tsunami wave propagation: Topics by Science.gov

Speeding up tsunami wave propagation modeling

NASA Astrophysics Data System (ADS)

Lavrentyev, Mikhail; Romanenko, Alexey

2014-05-01

Trans-oceanic wave propagation is one of the most time/CPU consuming parts of the tsunami modeling process. The so-called Method Of Splitting Tsunami (MOST) software package, developed at PMEL NOAA USA (Pacific Marine Environmental Laboratory of the National Oceanic and Atmospheric Administration, USA), is widely used to evaluate the tsunami parameters. However, it takes time to simulate trans-ocean wave propagation, that is up to 5 hours CPU time to "drive" the wave from Chili (epicenter) to the coast of Japan (even using a rather coarse computational mesh). Accurate wave height prediction requires fine meshes which leads to dramatic increase in time for simulation. Computation time is among the critical parameter as it takes only about 20 minutes for tsunami wave to approach the coast of Japan after earthquake at Japan trench or Sagami trench (as it was after the Great East Japan Earthquake on March 11, 2011). MOST solves numerically the hyperbolic system for three unknown functions, namely velocity vector and wave height (shallow water approximation). The system could be split into two independent systems by orthogonal directions (splitting method). Each system can be treated independently. This calculation scheme is well suited for SIMD architecture and GPUs as well. We performed adaptation of MOST package to GPU. Several numerical tests showed 40x performance gain for NVIDIA Tesla C2050 GPU vs. single core of Intel i7 processor. Results of numerical experiments were compared with other available simulation data. Calculation results, obtained at GPU, differ from the reference ones by 10^-3 cm of the wave height simulating 24 hours wave propagation. This allows us to speak about possibility to develop real-time system for evaluating tsunami danger.
Analytical and Numerical Modeling of Tsunami Wave Propagation for double layer state in Bore

NASA Astrophysics Data System (ADS)

Yuvaraj, V.; Rajasekaran, S.; Nagarajan, D.

2018-04-01

Tsunami wave enters into the river bore in the landslide. Tsunami wave propagation are described in two-layer states. The velocity and amplitude of the tsunami wave propagation are calculated using the double layer. The numerical and analytical solutions are given for the nonlinear equation of motion of the wave propagation in a bore.
NOAA Propagation Database Value in Tsunami Forecast Guidance

NASA Astrophysics Data System (ADS)

Eble, M. C.; Wright, L. M.

2016-02-01

The National Oceanic and Atmospheric Administration (NOAA) Center for Tsunami Research (NCTR) has developed a tsunami forecasting capability that combines a graphical user interface with data ingestion and numerical models to produce estimates of tsunami wave arrival times, amplitudes, current or water flow rates, and flooding at specific coastal communities. The capability integrates several key components: deep-ocean observations of tsunamis in real-time, a basin-wide pre-computed propagation database of water level and flow velocities based on potential pre-defined seismic unit sources, an inversion or fitting algorithm to refine the tsunami source based on the observations during an event, and tsunami forecast models. As tsunami waves propagate across the ocean, observations from the deep ocean are automatically ingested into the application in real-time to better define the source of the tsunami itself. Since passage of tsunami waves over a deep ocean reporting site is not immediate, we explore the value of the NOAA propagation database in providing placeholder forecasts in advance of deep ocean observations. The propagation database consists of water elevations and flow velocities pre-computed for 50 x 100 [km] unit sources in a continuous series along all known ocean subduction zones. The 2011 Japan Tohoku tsunami is presented as the case study
A Study of the Effects of Seafloor Topography on Tsunami Propagation

NASA Astrophysics Data System (ADS)

Ohata, T.; Mikada, H.; Goto, T.; Takekawa, J.

2011-12-01

For tsunami disaster mitigation, we consider the phenomena related to tsunami in terms of the generation, propagation, and run-up to the coast. With consideration for these three phenomena, we have to consider tsunami propagation to predict the arrival time and the run-up height of tsunami. Numerical simulations of tsunami that propagates from the source location to the coast have been widely used to estimate these important parameters. When a tsunami propagates, however, reflected and scattered waves arrive as later phases of tsunami. These waves are generated by the changes of water depth, and could influence the height estimation, especially in later phases. The maximum height of tsunami could be observed not as the first arrivals but as the later phases, therefore it is necessary to consider the effects of the seafloor topography on tsunami propagation. Since many simulations, however, mainly focus on the prediction of the first arrival times and the initial height of tsunami, it is difficult to simulate the later phases that are important for the tsunami disaster mitigation in the conventional methods. In this study, we investigate the effects of the seafloor topography on tsunami propagation after accommodating a tsunami simulation to the superposition of reflected and refracted waves caused by the smooth changes of water depths. Developing the new numerical code, we consider how the effects of the sea floor topography affect on the tsunami propagation, comparing with the tsunami simulated by the conventional method based on the liner long wave theory. Our simulation employs the three dimensional in-equally spaced grids in finite difference method (FDM) to introduce the real seafloor topography. In the simulation, we import the seafloor topography from the real bathymetry data near the Sendai-Bay, off the northeast Tohoku region, Japan, and simulate the tsunami propagation over the varying seafloor topography there. Comparing with the tsunami simulated by the
Role of Compressibility on Tsunami Propagation

NASA Astrophysics Data System (ADS)

Abdolali, Ali; Kirby, James T.

2017-12-01

In the present paper, we aim to reduce the discrepancies between tsunami arrival times evaluated from tsunami models and real measurements considering the role of ocean compressibility. We perform qualitative studies to reveal the phase speed reduction rate via a modified version of the Mild Slope Equation for Weakly Compressible fluid (MSEWC) proposed by Sammarco et al. (2013). The model is validated against a 3-D computational model. Physical properties of surface gravity waves are studied and compared with those for waves evaluated from an incompressible flow solver over realistic geometry for 2011 Tohoku-oki event, revealing reduction in phase speed.Plain Language SummarySubmarine earthquakes and submarine mass failures (SMFs), can generate long gravitational waves (or tsunamis) that propagate at the free surface. Tsunami waves can travel long distances and are known for their dramatic effects on coastal areas. Nowadays, numerical models are used to reconstruct the tsunamigenic events for many scientific and socioeconomic aspects i.e. Tsunami Early Warning Systems, inundation mapping, risk and hazard analysis, etc. A number of typically neglected parameters in these models cause discrepancies between model outputs and observations. Most of the tsunami models predict tsunami arrival times at distant stations slightly early in comparison to observations. In this study, we show how ocean compressibility would affect the tsunami wave propagation speed. In this framework, an efficient two-dimensional model equation for the weakly compressible ocean has been developed, validated and tested for simplified and real cases against three dimensional and incompressible solvers. Taking the effect of compressibility, the phase speed of surface gravity waves is reduced compared to that of an incompressible fluid. Then, we used the model for the case of devastating Tohoku-Oki 2011 tsunami event, improving the model accuracy. This </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2005AGUFMED53A0323L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2005AGUFMED53A0323L">The Waves and Tsunamis Project</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Lavin, M.; Strohschneider, D.; Maichle, R.; Frashure, K.; Micozzi, N.; Stephen, R. A. 2005-12-01 The goals of the Waves and Tsunamis Project are "to make waves real" to middle school students and to teach them some fundamental concepts of waves. The curriculum was designed in Fall 2004 (before the Sumatra Tsunami) and involves an ocean scientist classroom visit, hands-on demonstrations, and an interactive website designed to explain ocean wave properties. The website is called 'The Plymouth Wave Lab' and it has had more than 40,000 hits since the Sumatra event. One inexpensive and interesting demonstration is based on a string composed of alternating elastic bands and paper clips. Washers can be added to the paper clips to construct strings with varying mass. For example, a tapered string with mass decreasing in the wave propagation direction is an analog of tsunami waves propagating from deep to shallow water. The Waves and Tsunamis Project evolved as a collaborative effort involving an ocean science researcher and middle school science teachers. It was carried out through the direction of the Centers of Ocean Science Education Excellence New England (COSEE-NE) Ocean Science Education Institute (OSEI). COSEE-NE is involved in developing models for sustainable involvement of ocean science researchers in K-12 education ( http://necosee.net ). This work is supported by the National Science Foundation. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2003EAEJA......292W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2003EAEJA......292W">Generation, propagation and run-up of tsunamis due to the Chicxulub impact event</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Weisz, R.; Wuennenmann, K.; Bahlburg, H. 2003-04-01 The Chicxulub impact event can be investigated in (1) local, (2) regional and in (3) global scales. Our investigations focus on the regional scale, especially on the influence of tsunami waves on the coast around the Gulf of Mexico caused by the impact. During an impact two types of tsunamis are generated. The first wave is known as the "rim wave" and is generated in front of the ejecta curtain. The second one is linked to the late modification stage of the impact and results from the collapsing cavity of water. We designate this wave as "collapse wave". The "rim wave" and "collapse wave" are able to propagate over long distances, without a significant loss of wave amplitude. Corresponding to the amplitudes, the waves have a potentially large influence on the coastal areas. Run-up distance and run-up height can be used as parameters for describing this influence. We are utilizing a multimaterial hydrocode (SALE) to simulate the generation of tsunami waves. The propagation of the waves is based on the non-linear shallow water theory, because tsunami waves are defined to be long waves. The position of the coast line varies according to the tsunami run-up and is implemented with open boundary conditions. We show with our investigations (1) the generation of tsunami waves due to shallow water impacts, (2) wave damping during propagation, and (3) the influence of the "rim wave" and the "collapse wave" on the coastal areas. Here, we present our first results from numerical modeling of tsunami waves owing to a Chicxulub sized impactor. The characteristics of the “rim wave” depend on the size of the bolide and the water depth. However, the amplitude and velocity of the “collapse wave” is only determined by the water depth in the impact area. The numerical modeling of the tsunami propagation and run-up is calculated along a section from the impact point towards to the west and gives the moderate damping of both waves and the run-up on the coastal area. As a first </li> <li> <a target="_blank" onclick="trackOutboundLink('http://www.dtic.mil/docs/citations/ADA567535','DTIC-ST'); return false;" href="http://www.dtic.mil/docs/citations/ADA567535">Tsunami Propagation Models Based on First Principles</a> <a target="_blank" href="http://www.dtic.mil/">DTIC Science & Technology</a> 2012-11-21 geodesic lines from the epicenter shown in the figure are great circles with a longitudinal separation of 90o, which define a ‘ lune ’ that covers one...past which the waves begin to converge according to Model C. A tsunami propagating in this lune does not encounter any continental landmass until...2011 Japan tsunami in a lune of angle 90o with wavefronts at intervals of 5,000 km The 2011 Japan tsunami was felt throughout the Pacific Ocean </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2007AGUFM.S53A1036M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2007AGUFM.S53A1036M">New Theory for Tsunami Propagation and Estimation of Tsunami Source Parameters</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Mindlin, I. M. 2007-12-01 In numerical studies based on the shallow water equations for tsunami propagation, vertical accelerations and velocities within the sea water are neglected, so a tsunami is usually supposed to be produced by an initial free surface displacement in the initially still sea. In the present work, new theory for tsunami propagation across the deep sea is discussed, that accounts for the vertical accelerations and velocities. The theory is based on the solutions for the water surface displacement obtained in [Mindlin I.M. Integrodifferential equations in dynamics of a heavy layered liquid. Moscow: Nauka*Fizmatlit, 1996 (Russian)]. The solutions are valid when horizontal dimensions of the initially disturbed area in the sea surface are much larger than the vertical displacement of the surface, which applies to the earthquake tsunamis. It is shown that any tsunami is a combination of specific basic waves found analytically (not superposition: the waves are nonlinear), and consequently, the tsunami source (i.e., the initially disturbed body of water) can be described by the numerable set of the parameters involved in the combination. Thus the problem of theoretical reconstruction of a tsunami source is reduced to the problem of estimation of the parameters. The tsunami source can be modelled approximately with the use of a finite number of the parameters. Two-parametric model is discussed thoroughly. A method is developed for estimation of the model's parameters using the arrival times of the tsunami at certain locations, the maximum wave-heights obtained from tide gauge records at the locations, and the distances between the earthquake's epicentre and each of the locations. In order to evaluate the practical use of the theory, four tsunamis of different magnitude occurred in Japan are considered. For each of the tsunamis, the tsunami energy (E below), the duration of the tsunami source formation T, the maximum water elevation in the wave originating area H, mean radius of </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015E%26ES...23a2007Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015E%26ES...23a2007Z">A shallow water model for the propagation of tsunami via Lattice Boltzmann method</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Zergani, Sara; Aziz, Z. A.; Viswanathan, K. K. 2015-01-01 An efficient implementation of the lattice Boltzmann method (LBM) for the numerical simulation of the propagation of long ocean waves (e.g. tsunami), based on the nonlinear shallow water (NSW) wave equation is presented. The LBM is an alternative numerical procedure for the description of incompressible hydrodynamics and has the potential to serve as an efficient solver for incompressible flows in complex geometries. This work proposes the NSW equations for the irrotational surface waves in the case of complex bottom elevation. In recent time, equation involving shallow water is the current norm in modelling tsunami operations which include the propagation zone estimation. Several test-cases are presented to verify our model. Some implications to tsunami wave modelling are also discussed. Numerical results are found to be in excellent agreement with theory. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017JGRC..122.5786B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017JGRC..122.5786B">Tsunami and infragravity waves impacting Antarctic ice shelves</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Bromirski, P. D.; Chen, Z.; Stephen, R. A.; Gerstoft, P.; Arcas, D.; Diez, A.; Aster, R. C.; Wiens, D. A.; Nyblade, A. 2017-07-01 The responses of the Ross Ice Shelf (RIS) to the 16 September 2015 8.3 (Mw) Chilean earthquake tsunami (>75 s period) and to oceanic infragravity (IG) waves (50-300 s period) were recorded by a broadband seismic array deployed on the RIS from November 2014 to November 2016. Here we show that tsunami and IG-generated signals within the RIS propagate at gravity wave speeds (˜70 m/s) as water-ice coupled flexural-gravity waves. IG band signals show measureable attenuation away from the shelf front. The response of the RIS to Chilean tsunami arrivals is compared with modeled tsunami forcing to assess ice shelf flexural-gravity wave excitation by very long period (VLP; >300 s) gravity waves. Displacements across the RIS are affected by gravity wave incident direction, bathymetry under and north of the shelf, and water layer and ice shelf thicknesses. Horizontal displacements are typically about 10 times larger than vertical displacements, producing dynamical extensional motions that may facilitate expansion of existing fractures. VLP excitation is continuously observed throughout the year, with horizontal displacements highest during the austral winter with amplitudes exceeding 20 cm. Because VLP flexural-gravity waves exhibit no discernable attenuation, this energy must propagate to the grounding zone. Both IG and VLP band flexural-gravity waves excite mechanical perturbations of the RIS that likely promote tabular iceberg calving, consequently affecting ice shelf evolution. Understanding these ocean-excited mechanical interactions is important to determine their effect on ice shelf stability to reduce uncertainty in the magnitude and rate of global sea level rise. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018GeoJI.tmp..199P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018GeoJI.tmp..199P">Traveltime delay relative to the maximum energy of the wave train for dispersive tsunamis propagating across the Pacific Ocean: the case of 2010 and 2015 Chilean Tsunamis</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Poupardin, A.; Heinrich, P.; Hébert, H.; Schindelé, F.; Jamelot, A.; Reymond, D.; Sugioka, H. 2018-05-01 This paper evaluates the importance of frequency dispersion in the propagation of recent trans-Pacific tsunamis. Frequency dispersion induces a time delay for the most energetic waves, which increases for long propagation distances and short source dimensions. To calculate this time delay, propagation of tsunamis is simulated and analyzed from spectrograms of time-series at specific gauges in the Pacific Ocean. One- and two-dimensional simulations are performed by solving either shallow water or Boussinesq equations and by considering realistic seismic sources. One-dimensional sensitivity tests are first performed in a constant-depth channel to study the influence of the source width. Two-dimensional tests are then performed in a simulated Pacific Ocean with a 4000-m constant depth and by considering tectonic sources of 2010 and 2015 Chilean earthquakes. For these sources, both the azimuth and the distance play a major role in the frequency dispersion of tsunamis. Finally, simulations are performed considering the real bathymetry of the Pacific Ocean. Multiple reflections, refractions as well as shoaling of waves result in much more complex time series for which the effects of the frequency dispersion are hardly discernible. The main point of this study is to evaluate frequency dispersion in terms of traveltime delays by calculating spectrograms for a time window of 6 hours after the arrival of the first wave. Results of the spectral analysis show that the wave packets recorded by pressure and tide sensors in the Pacific Ocean seem to be better reproduced by the Boussinesq model than the shallow water model and approximately follow the theoretical dispersion relationship linking wave arrival times and frequencies. Additionally, a traveltime delay is determined above which effects of frequency dispersion are considered to be significant in terms of maximum surface elevations. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010EGUGA..12...38M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010EGUGA..12...38M">Influence of source extension of 26 December 2004 Sumatra earthquake on character of tsunami wave propagation</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Mazova, Raissa; Kisel'Man, Broneslav; Baranova, Natalya; Lobkovsky, Leopold 2010-05-01 The analysis of the Indian Ocean earthquake and tsunami on 26 December 2004 carried out in a number of works demonstrates that rupture process in the seismic source was realized during several minutes. In some works, there was suggested that a source probably consists of several segments with width near above hundred of kilometers and with total length more than 1000 km. Such a picture is consistent with subduction keyboard model of tsunamigenic earthquake (see, e.g. [1]) which treats the anomalously long source of Indian Ocean tsunami, caused by oblique subduction, as a multiblock piston mechanism with non-simultaneous realization of each block. Because of existing in literature uncertainty with source structure and movements at all its extent, it is interesting for given event to study in details the dependence of characteristics of surface water wave induced by seismic source on its extent [1,2]. In the work it was studied the influence of submarine seismic source extention to wave field distribution in basin of Bengal bay and central part of Indian ocean. To analyze, it was considered separately the influence of large segment of seismic source for given tsunami. On the basis of keyboard model it is considered the earthquake origin with extension near 1200 km comprises 3 seismic source: Sumatran, Andaman and Nicobar ones, each of which comprises 6, 4 and 3 keyboard blocks, respectively (1, 2 and 3 scenarios). It was calculated the maximal vertical displacement of these segments on 2-5 meters. The velocity of block movement was taken in correspondence with available data on characteristic times in the source. For scenario 1 tsunami source, formed at the ocean surface, generates almost circular wave which, due to bathymetry of given basin, preserve its form and propagates most quickly in west and south-west direction. To north-east, to Indian coast, the wave came with large delay, as compared with records of real mareographs. As follows from the wave field picture </li> <li> <a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/pages/biblio/1212469-first-tsunami-gravity-wave-detection-ionospheric-radio-occultation-data','SCIGOV-DOEP'); return false;" href="https://www.osti.gov/pages/biblio/1212469-first-tsunami-gravity-wave-detection-ionospheric-radio-occultation-data">First tsunami gravity wave detection in ionospheric radio occultation data</a> <a target="_blank" href="http://www.osti.gov/pages">DOE PAGES</a> Coïsson, Pierdavide; Lognonné, Philippe; Walwer, Damian; ... 2015-05-09 After the 11 March 2011 earthquake and tsunami off the coast of Tohoku, the ionospheric signature of the displacements induced in the overlying atmosphere has been observed by ground stations in various regions of the Pacific Ocean. We analyze here the data of radio occultation satellites, detecting the tsunami-driven gravity wave for the first time using a fully space-based ionospheric observation system. One satellite of the Constellation Observing System for Meteorology, Ionosphere and Climate (COSMIC) recorded an occultation in the region above the tsunami 2.5 h after the earthquake. The ionosphere was sounded from top to bottom, thus providing themore » vertical structure of the gravity wave excited by the tsunami propagation, observed as oscillations of the ionospheric Total Electron Content (TEC). The observed vertical wavelength was about 50 km, with maximum amplitude exceeding 1 total electron content unit when the occultation reached 200 km height. We compared the observations with synthetic data obtained by summation of the tsunami-coupled gravity normal modes of the Earth/Ocean/atmosphere system, which models the associated motion of the ionosphere plasma. These results provide experimental constraints on the attenuation of the gravity wave with altitude due to atmosphere viscosity, improving the understanding of the propagation of tsunami-driven gravity waves in the upper atmosphere. They demonstrate that the amplitude of the tsunami can be estimated to within 20% by the recorded ionospheric data.« less </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017SPIE10466E..4VS','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017SPIE10466E..4VS">Cloud manifestations of atmospheric gravity waves over the water area of the Kuril Islands during the propagation of powerful transoceanic tsunamis</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Skorokhodov, A. V.; Shevchenko, G. V.; Astafurov, V. G. 2017-11-01 The investigation results of atmospheric gravity waves cloudy manifestations observed over the water area of the Kuril Island ridge during the propagation of powerful transoceanic tsunami 2009-2010 are shown. The description of tsunami characteristics is based on the use of information from autonomous deep-water stations of the Institute of Marine Geology and Geophysics FEB RAS in the Southern Kuril Islands and the Tsunami Warning Service telemetering recorder located in one of the ports on Paramushir Island. The environment condition information was extracted from the results of remote sensing of the Earth from space by the MODIS sensor and aerological measurements at the meteorological station of Severo-Kurilsk. The results of analyzing the characteristics of wave processes in the atmosphere and the ocean are discussed and their comparison is carried out. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013EGUGA..15.4765N','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013EGUGA..15.4765N">An Earthquake Source Sensitivity Analysis for Tsunami Propagation in the Eastern Mediterranean</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Necmioglu, Ocal; Meral Ozel, Nurcan 2013-04-01 An earthquake source parameter sensitivity analysis for tsunami propagation in the Eastern Mediterranean has been performed based on 8 August 1303 Crete and Dodecanese Islands earthquake resulting in destructive inundation in the Eastern Mediterranean. The analysis involves 23 cases describing different sets of strike, dip, rake and focal depth, while keeping the fault area and displacement, thus the magnitude, same. The main conclusions of the evaluation are drawn from the investigation of the wave height distributions at Tsunami Forecast Points (TFP). The earthquake vs. initial tsunami source parameters comparison indicated that the maximum initial wave height values correspond in general to the changes in rake angle. No clear depth dependency is observed within the depth range considered and no strike angle dependency is observed in terms of amplitude change. Directivity sensitivity analysis indicated that for the same strike and dip, 180° shift in rake may lead to 20% change in the calculated tsunami wave height. Moreover, an approximately 10 min difference in the arrival time of the initial wave has been observed. These differences are, however, greatly reduced in the far field. The dip sensitivity analysis, performed separately for thrust and normal faulting, has both indicated that an increase in the dip angle results in the decrease of the tsunami wave amplitude in the near field approximately 40%. While a positive phase shift is observed, the period and the shape of the initial wave stays nearly the same for all dip angles at respective TFPs. These affects are, however, not observed at the far field. The resolution of the bathymetry, on the other hand, is a limiting factor for further evaluation. Four different cases were considered for the depth sensitivity indicating that within the depth ranges considered (15-60 km), the increase of the depth has only a smoothing effect on the synthetic tsunami wave height measurements at the selected TFPs. The strike </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016EGUGA..1811809K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016EGUGA..1811809K">Tsunami focusing and leading wave height</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Kanoglu, Utku 2016-04-01 Field observations from tsunami events show that sometimes the maximum tsunami amplitude might not occur for the first wave, such as the maximum wave from the 2011 Japan tsunami reaching to Papeete, Tahiti as a fourth wave 72 min later after the first wave. This might mislead local authorities and give a wrong sense of security to the public. Recently, Okal and Synolakis (2016, Geophys. J. Int. 204, 719-735) discussed "the factors contributing to the sequencing of tsunami waves in the far field." They consider two different generation mechanisms through an axial symmetric source -circular plug; one, Le Mehaute and Wang's (1995, World Scientific, 367 pp.) formalism where irritational wave propagation is formulated in the framework of investigating tsunamis generated by underwater explosions and two, Hammack's formulation (1972, Ph.D. Dissertation, Calif. Inst. Tech., 261 pp., Pasadena) which introduces deformation at the ocean bottom and does not represent an immediate deformation of the ocean surface, i.e. time dependent ocean surface deformation. They identify the critical distance for transition from the first wave being largest to the second wave being largest. To verify sequencing for a finite length source, Okal and Synolakis (2016) is then used NOAA's validated and verified real time forecasting numerical model MOST (Titov and Synolakis, 1998, J. Waterw. Port Coast. Ocean Eng., 124, 157-171) through Synolakis et al. (2008, Pure Appl. Geophys. 165, 2197-2228). As a reference, they used the parameters of the 1 April 2014 Iquique, Chile earthquake over real bathymetry, variants of this source (small, big, wide, thin, and long) over a flat bathymetry, and 2010 Chile and 211 Japan tsunamis over both real and flat bathymetries to explore the influence of the fault parameters on sequencing. They identified that sequencing more influenced by the source width rather than the length. We extend Okal and Synolakis (2016)'s analysis to an initial N-wave form (Tadepalli </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017ISPAr42W7.1291M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017ISPAr42W7.1291M">Spatiotemporal Visualization of Tsunami Waves Using Kml on Google Earth</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Mohammadi, H.; Delavar, M. R.; Sharifi, M. A.; Pirooz, M. D. 2017-09-01 Disaster risk is a function of hazard and vulnerability. Risk is defined as the expected losses, including lives, personal injuries, property damages, and economic disruptions, due to a particular hazard for a given area and time period. Risk assessment is one of the key elements of a natural disaster management strategy as it allows for better disaster mitigation and preparation. It provides input for informed decision making, and increases risk awareness among decision makers and other stakeholders. Virtual globes such as Google Earth can be used as a visualization tool. Proper spatiotemporal graphical representations of the concerned risk significantly reduces the amount of effort to visualize the impact of the risk and improves the efficiency of the decision-making process to mitigate the impact of the risk. The spatiotemporal visualization of tsunami waves for disaster management process is an attractive topic in geosciences to assist investigation of areas at tsunami risk. In this paper, a method for coupling virtual globes with tsunami wave arrival time models is presented. In this process we have shown 2D+Time of tsunami waves for propagation and inundation of tsunami waves, both coastal line deformation, and the flooded areas. In addition, the worst case scenario of tsunami on Chabahar port derived from tsunami modelling is also presented using KML on google earth. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009EGUGA..11..502P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009EGUGA..11..502P">The 1755 tsunami propagation in Atlantics and its effects on the French West Indies</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Pelinovsky, E.; Zahibo, N.; Yalciner, A.; Zaitsev, A.; Talipova, T.; Chernov, A.; Insel, I.; Dilmen, D.; Ozer, C.; Nikolkina, I. 2009-04-01 The present study examines the propagation of tsunami waves generated by the 1755 Lisbon earthquake in the Atlantic Ocean and its effects on the coasts of the French West Indies in the Caribbean Sea. Historical data of tsunami manifestation in the French West Indies are briefly reproduced. The mathematical model named NAMI DANCE which solves the shallow-water equations has been applied in the computations. Three possible seismic source alternatives of the tsunami source are selected for 1755 event in the simulations. The results obtained from the simulations demonstrate that the directivity of tsunami energy is divided into two strong beams directed to the southern part of North America (Florida, the Bahamas) and to the northern part of South America (Brazil). The tsunami waves reach the Lesser Antilles in 7 hrs. The computed distribution of tsunami wave height along the coasts of Guadeloupe and Martinique are presented. Calculated maximum of wave amplitudes reached 2 m in Guadeloupe and 1.5 m in Martinique. These results are also in agreement with observed data (1.8 - 3 m). The experience and data obtained in this study show that transatlantic events must also be considered in the tsunami hazard assessment and development of mitigation strategies for the French West Indies. </li> <li> <a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26119833','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26119833">Widespread tsunami-like waves of 23-27 June in the Mediterranean and Black Seas generated by high-altitude atmospheric forcing.</a> <a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a> Šepić, Jadranka; Vilibić, Ivica; Rabinovich, Alexander B; Monserrat, Sebastian 2015-06-29 A series of tsunami-like waves of non-seismic origin struck several southern European countries during the period of 23 to 27 June 2014. The event caused considerable damage from Spain to Ukraine. Here, we show that these waves were long-period ocean oscillations known as meteorological tsunamis which are generated by intense small-scale air pressure disturbances. An unique atmospheric synoptic pattern was tracked propagating eastward over the Mediterranean and the Black seas in synchrony with onset times of observed tsunami waves. This pattern favoured generation and propagation of atmospheric gravity waves that induced pronounced tsunami-like waves through the Proudman resonance mechanism. This is the first documented case of a chain of destructive meteorological tsunamis occurring over a distance of thousands of kilometres. Our findings further demonstrate that these events represent potentially dangerous regional phenomena and should be included in tsunami warning systems. </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li class="active">1</li> <li><a href="#" onclick='return showDiv("page_2");'>2</a></li> <li><a href="#" onclick='return showDiv("page_3");'>3</a></li> <li><a href="#" onclick='return showDiv("page_4");'>4</a></li> <li><a href="#" onclick='return showDiv("page_5");'>5</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> </div> <div id="page_2" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_1");'>1</a></li> <li class="active">2</li> <li><a href="#" onclick='return showDiv("page_3");'>3</a></li> <li><a href="#" onclick='return showDiv("page_4");'>4</a></li> <li><a href="#" onclick='return showDiv("page_5");'>5</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="21"> <li> <a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4483776','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4483776">Widespread tsunami-like waves of 23-27 June in the Mediterranean and Black Seas generated by high-altitude atmospheric forcing</a> <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a> Šepić, Jadranka; Vilibić, Ivica; Rabinovich, Alexander B.; Monserrat, Sebastian 2015-01-01 A series of tsunami-like waves of non-seismic origin struck several southern European countries during the period of 23 to 27 June 2014. The event caused considerable damage from Spain to Ukraine. Here, we show that these waves were long-period ocean oscillations known as meteorological tsunamis which are generated by intense small-scale air pressure disturbances. An unique atmospheric synoptic pattern was tracked propagating eastward over the Mediterranean and the Black seas in synchrony with onset times of observed tsunami waves. This pattern favoured generation and propagation of atmospheric gravity waves that induced pronounced tsunami-like waves through the Proudman resonance mechanism. This is the first documented case of a chain of destructive meteorological tsunamis occurring over a distance of thousands of kilometres. Our findings further demonstrate that these events represent potentially dangerous regional phenomena and should be included in tsunami warning systems. PMID:26119833 </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFMNH14A..04T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFMNH14A..04T">Tsunami Waves Joint Inversion Using Tsunami Inundation, Tsunami Deposits Distribution and Marine-Terrestrial Sediment Signal in Tsunami Deposit</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Tang, H.; WANG, J. 2017-12-01 Population living close to coastlines is increasing, which creates higher risks due to coastal hazards, such as the tsunami. However, the generation of a tsunami is not fully understood yet, especially for paleo-tsunami. Tsunami deposits are one of the concrete evidence in the geological record which we can apply for studying paleo-tsunami. The understanding of tsunami deposits has significantly improved over the last decades. There are many inversion models (e.g. TsuSedMod, TSUFLIND, and TSUFLIND-EnKF) to study the overland-flow characteristics based on tsunami deposits. However, none of them tries to reconstruct offshore tsunami wave characteristics (wave form, wave height, and length) based on tsunami deposits. Here we present a state-of-the-art inverse approach to reconstruct offshore tsunami wave based on the tsunami inundation data, the spatial distribution of tsunami deposits and Marine-terrestrial sediment signal in the tsunami deposits. Ensemble Kalman Filter (EnKF) Method is used for assimilating both sediment transport simulations and the field observation data. While more computationally expensive, the EnKF approach potentially provides more accurate reconstructions for tsunami waveform. In addition to the improvement of inversion results, the ensemble-based method can also quantify the uncertainties of the results. Meanwhile, joint inversion improves the resolution of tsunami waves compared with inversions using any single data type. The method will be tested by field survey data and gauge data from the 2011 Tohoku tsunami on Sendai plain area. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018JGRA..123.4329R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018JGRA..123.4329R">Tsunami Wave Height Estimation from GPS-Derived Ionospheric Data</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Rakoto, Virgile; Lognonné, Philippe; Rolland, Lucie; Coïsson, P. 2018-05-01 Large underwater earthquakes (Mw>7) can transmit part of their energy to the surrounding ocean through large seafloor motions, generating tsunamis that propagate over long distances. The forcing effect of tsunami waves on the atmosphere generates internal gravity waves that, when they reach the upper atmosphere, produce ionospheric perturbations. These perturbations are frequently observed in the total electron content (TEC) measured by multifrequency Global Navigation Satellite Systems (GNSS) such as GPS, GLONASS, and, in the future, Galileo. This paper describes the first inversion of the variation in sea level derived from GPS TEC data. We used a least squares inversion through a normal-mode summation modeling. This technique was applied to three tsunamis in far field associated to the 2012 Haida Gwaii, 2006 Kuril Islands, and 2011 Tohoku events and for Tohoku also in close field. With the exception of the Tohoku far-field case, for which the tsunami reconstruction by the TEC inversion is less efficient due to the ionospheric noise background associated to geomagnetic storm, which occurred on the earthquake day, we show that the peak-to-peak amplitude of the sea level variation inverted by this method can be compared to the tsunami wave height measured by a DART buoy with an error of less than 20%. This demonstrates that the inversion of TEC data with a tsunami normal-mode summation approach is able to estimate quite accurately the amplitude and waveform of the first tsunami arrival. </li> <li> <a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70036889','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70036889">Hydrodynamic modeling of tsunamis from the Currituck landslide</a> <a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a> Geist, E.L.; Lynett, P.J.; Chaytor, J.D. 2009-01-01 Tsunami generation from the Currituck landslide offshore North Carolina and propagation of waves toward the U.S. coastline are modeled based on recent geotechnical analysis of slide movement. A long and intermediate wave modeling package (COULWAVE) based on the non-linear Boussinesq equations are used to simulate the tsunami. This model includes procedures to incorporate bottom friction, wave breaking, and overland flow during runup. Potential tsunamis generated from the Currituck landslide are analyzed using four approaches: (1) tsunami wave history is calculated from several different scenarios indicated by geotechnical stability and mobility analyses; (2) a sensitivity analysis is conducted to determine the effects of both landslide failure duration during generation and bottom friction along the continental shelf during propagation; (3) wave history is calculated over a regional area to determine the propagation of energy oblique to the slide axis; and (4) a high-resolution 1D model is developed to accurately model wave breaking and the combined influence of nonlinearity and dispersion during nearshore propagation and runup. The primary source parameter that affects tsunami severity for this case study is landslide volume, with failure duration having a secondary influence. Bottom friction during propagation across the continental shelf has a strong influence on the attenuation of the tsunami during propagation. The high-resolution 1D model also indicates that the tsunami undergoes nonlinear fission prior to wave breaking, generating independent, short-period waves. Wave breaking occurs approximately 40-50??km offshore where a tsunami bore is formed that persists during runup. These analyses illustrate the complex nature of landslide tsunamis, necessitating the use of detailed landslide stability/mobility models and higher-order hydrodynamic models to determine their hazard. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFMNH51C..01H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFMNH51C..01H">Tsunami-Generated Atmospheric Gravity Waves and Their Atmospheric and Ionospheric Effects: a Review and Some Recent Modeling Results</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Hickey, M. P. 2017-12-01 Tsunamis propagate on the ocean surface at the shallow water phase speed which coincides with the phase speed of fast atmospheric gravity waves. The forcing frequency also corresponds with those of internal atmospheric gravity waves. Hence, the coupling and effective forcing of gravity waves due to tsunamis is particularly effective. The fast horizontal phase speeds of the resulting gravity waves allows them to propagate well into the thermosphere before viscous dissipation becomes strong, and the waves can achieve nonlinear amplitudes at these heights resulting in large amplitude traveling ionospheric disturbances (TIDs). Additionally, because the tsunami represents a moving source able to traverse large distances across the globe, the gravity waves and associated TIDs can be detected at large distances from the original tsunami (earthquake) source. Although it was during the mid 1970s when the tsunami source of gravity waves was first postulated, only relatively recently (over the last ten to fifteen years) has there has been a surge of interest in this research arena, driven largely by significant improvements in measurement technologies and computational capabilities. For example, the use of GPS measurements to derive total electron content has been a particularly powerful technique used to monitor the propagation and evolution of TIDs. Monitoring airglow variations driven by atmospheric gravity waves has also been a useful technique. The modeling of specific events and comparison with the observed gravity waves and/or TIDs has been quite revealing. In this talk I will review some of the most interesting aspects of this research and also discuss some interesting and outstanding issues that need to be addressed. New modeling results relevant to the Tohoku tsunami event will also be presented. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFMNH21D..08S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFMNH21D..08S">Challenges in Defining Tsunami Wave Height</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Stroker, K. J.; Dunbar, P. K.; Mungov, G.; Sweeney, A.; Arcos, N. P. 2017-12-01 The NOAA National Centers for Environmental Information (NCEI) and co-located World Data Service for Geophysics maintain the global tsunami archive consisting of the historical tsunami database, imagery, and raw and processed water level data. The historical tsunami database incorporates, where available, maximum wave heights for each coastal tide gauge and deep-ocean buoy that recorded a tsunami signal. These data are important because they are used for tsunami hazard assessment, model calibration, validation, and forecast and warning. There have been ongoing discussions in the tsunami community about the correct way to measure and report these wave heights. It is important to understand how these measurements might vary depending on how the data were processed and the definition of maximum wave height. On September 16, 2015, an 8.3 Mw earthquake located 48 km west of Illapel, Chile generated a tsunami that was observed all over the Pacific region. We processed the time-series water level data for 57 tide gauges that recorded this tsunami and compared the maximum wave heights determined from different definitions. We also compared the maximum wave heights from the NCEI-processed data with the heights reported by the NOAA Tsunami Warning Centers. We found that in the near field different methods of determining the maximum tsunami wave heights could result in large differences due to possible instrumental clipping. We also found that the maximum peak is usually larger than the maximum amplitude (½ peak-to-trough), but the differences for the majority of the stations were <20 cm. For this event, the maximum tsunami wave heights determined by either definition (maximum peak or amplitude) would have validated the forecasts issued by the NOAA Tsunami Warning Centers. Since there is currently only one field in the NCEI historical tsunami database to store the maximum tsunami wave height, NCEI will consider adding an additional field for the maximum peak measurement. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017PApGe.174.3043D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017PApGe.174.3043D">Challenges in Defining Tsunami Wave Heights</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Dunbar, Paula; Mungov, George; Sweeney, Aaron; Stroker, Kelly; Arcos, Nicolas 2017-08-01 The National Oceanic and Atmospheric Administration (NOAA) National Centers for Environmental Information (NCEI) and co-located World Data Service for Geophysics maintain the global tsunami archive consisting of the historical tsunami database, imagery, and raw and processed water level data. The historical tsunami database incorporates, where available, maximum wave heights for each coastal tide gauge and deep-ocean buoy that recorded a tsunami signal. These data are important because they are used for tsunami hazard assessment, model calibration, validation, and forecast and warning. There have been ongoing discussions in the tsunami community about the correct way to measure and report these wave heights. It is important to understand how these measurements might vary depending on how the data were processed and the definition of maximum wave height. On September 16, 2015, an 8.3 M w earthquake located 48 km west of Illapel, Chile generated a tsunami that was observed all over the Pacific region. We processed the time-series water level data for 57 coastal tide gauges that recorded this tsunami and compared the maximum wave heights determined from different definitions. We also compared the maximum wave heights from the NCEI-processed data with the heights reported by the NOAA Tsunami Warning Centers. We found that in the near field different methods of determining the maximum tsunami wave heights could result in large differences due to possible instrumental clipping. We also found that the maximum peak is usually larger than the maximum amplitude (½ peak-to-trough), but the differences for the majority of the stations were <20 cm. For this event, the maximum tsunami wave heights determined by either definition (maximum peak or amplitude) would have validated the forecasts issued by the NOAA Tsunami Warning Centers. Since there is currently only one field in the NCEI historical tsunami database to store the maximum tsunami wave height for each tide gauge and </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017EGUGA..19.3805R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017EGUGA..19.3805R">DTWT (Dispersive Tsunami Wave Tool): a new tool for computing the complete dispersion of tsunami travel time.</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Reymond, Dominique 2017-04-01 We present a tool for computing the complete arrival times of the dispersed wave-train of a tsunami. The calculus is made using the exact formulation of the tsunami dispersion (and without approximations), at any desired periods between one hour or more (concerning the gravity waves propagation) until 10s (the highly dispersed mode). The computation of the travel times is based on the a summation of the necessary time for a tsunami to cross all the elementary blocs of a grid of bathymetry following a path between the source and receiver at a given period. In addition the source dimensions and the focal mechanism are taken into account to adjust the minimum travel time to the different possible points of emission of the source. A possible application of this tool is to forecast the arrival time of late arrivals of tsunami waves that could produce the resonnance of some bays and sites at higher frequencies than the gravity mode. The theoretical arrival times are compared to the observed ones and to the results obtained by TTT (P. Wessel, 2009) and the ones obtained by numerical simulations. References: Wessel, P. (2009). Analysis of oberved and predicted tsunami travel times for the Pacic and Indian oceans. Pure Appl. Geophys., 166:301-324. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFMNH14A..08T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFMNH14A..08T">Modeling Extra-Long Tsunami Propagation: Assessing Data, Model Accuracy and Forecast Implications</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Titov, V. V.; Moore, C. W.; Rabinovich, A. 2017-12-01 Detecting and modeling tsunamis propagating tens of thousands of kilometers from the source is a formidable scientific challenge and seemingly satisfies only scientific curiosity. However, results of such analyses produce a valuable insight into the tsunami propagation dynamics, model accuracy and would provide important implications for tsunami forecast. The Mw = 9.3 megathrust earthquake of December 26, 2004 off the coast of Sumatra generated a tsunami that devastated Indian Ocean coastlines and spread into the Pacific and Atlantic oceans. The tsunami was recorded by a great number of coastal tide gauges, including those located in 15-25 thousand kilometers from the source area. To date, it is still the farthest instrumentally detected tsunami. The data from these instruments throughout the world oceans enabled to estimate various statistical parameters and energy decay of this event. High-resolution records of this tsunami from DARTs 32401 (offshore of northern Chile), 46405 and NeMO (both offshore of the US West Coast), combined with the mainland tide gauge measurements enabled us to examine far-field characteristics of the 2004 in the Pacific Ocean and to compare the results of global numerical simulations with the observations. Despite their small heights (less than 2 cm at deep-ocean locations), the records demonstrated consistent spatial and temporal structure. The numerical model described well the frequency content, amplitudes and general structure of the observed waves at deep-ocean and coastal gages. We present analysis of the measurements and comparison with model data to discuss implication for tsunami forecast accuracy. Model study for such extreme distances from the tsunami source and at extra-long times after the event is an attempt to find accuracy bounds for tsunami models and accuracy limitations of model use for forecast. We discuss results in application to tsunami model forecast and tsunami modeling in general. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AGUFMNH23A1870J','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AGUFMNH23A1870J">Sensitivity of Tsunami Waves and Coastal Inundation/Runup to Seabed Displacement Models: Application to the Cascadia Subduction zone</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Jalali Farahani, R.; Fitzenz, D. D.; Nyst, M. 2015-12-01 Major components of tsunami hazard modeling include earthquake source characterization, seabed displacement, wave propagation, and coastal inundation/run-up. Accurate modeling of these components is essential to identify the disaster risk exposures effectively, which would be crucial for insurance industry as well as policy makers to have tsunami resistant design of structures and evacuation planning (FEMA, 2008). In this study, the sensitivity and variability of tsunami coastal inundation due to Cascadia megathrust subduction earthquake are studied by considering the different approaches for seabed displacement model. The first approach is the analytical expressions that were proposed by Okada (1985, 1992) for the surface displacements and strains of rectangular sources. The second approach was introduced by Meade (2006) who introduced analytical solutions for calculating displacements, strains, and stresses on triangular sources. In this study, the seabed displacement using triangular representation of geometrically complex fault surfaces is compared with the Okada rectangular representations for the Cascadia subduction zone. In the triangular dislocation algorithm, the displacement is calculated using superposition of two angular dislocations for each of the three triangle legs. The triangular elements could give a better and gap-free representation of the fault surfaces. In addition, the rectangular representation gives large unphysical vertical displacement along the shallow-depth fault edge that generates unrealistic short-wavelength waves. To study the impact of these two different algorithms on the final tsunami inundation, the initial tsunami wave as well as wave propagation and the coastal inundation are simulated. To model the propagation of tsunami waves and coastal inundation, 2D shallow water equations are modeled using the seabed displacement as the initial condition for the numerical model. Tsunami numerical simulation has been performed on high </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015EGUGA..17..636K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015EGUGA..17..636K">Transformation of tsunami waves passing through the Straits of the Kuril Islands</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Kostenko, Irina; Kurkin, Andrey; Pelinovsky, Efim; Zaytsev, Andrey 2015-04-01 Pacific ocean and themselves Kuril Islands are located in the zone of high seismic activity, where underwater earthquakes cause tsunamis. They propagate across Pacific ocean and penetrates into the Okhotsk sea. It is natural to expect that the Kuril Islands reflect the Okhotsk sea from the Pacific tsunami waves. It has long been noted that the historical tsunami appeared less intense in the sea of Okhotsk in comparison with the Pacific coast of the Kuril Islands. Despite the fact that in the area of the Kuril Islands and in the Pacific ocean earthquakes with magnitude more than 8 occur, in the entire history of observations on the Okhotsk sea coast catastrophic tsunami was not registered. The study of the peculiarities of the propagation of historical and hypothetical tsunami in the North-Eastern part of the Pacific ocean was carried out in order to identify level of effect of the Kuril Islands and Straits on them. Tsunami sources were located in the Okhotsk sea and in the Pacific ocean. For this purpose, we performed a series of computational experiments using two bathymetries: 1) with use Kuril Islands; 2) without Kuril Islands. Magnitude and intensity of the tsunami, obtained during numerical simulation of height, were analyzed. The simulation results are compared with the observations. Numerical experiments have shown that in the simulation without the Kuril Islands tsunamis in the Okhotsk sea have higher waves, and in the Central part of the sea relatively quickly damped than in fact. Based on shallow-water equation tsunami numerical code NAMI DANCE was used for numerical simulations. This work was supported by ASTARTE project. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AGUFMNH23A1867K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AGUFMNH23A1867K">Leading Wave Amplitude of a Tsunami</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Kanoglu, U. 2015-12-01 Okal and Synolakis (EGU General Assembly 2015, Geophysical Research Abstracts-Vol. 17-7622) recently discussed that why the maximum amplitude of a tsunami might not occur for the first wave. Okal and Synolakis list observations from 2011 Japan tsunami, which reached to Papeete, Tahiti with a fourth wave being largest and 72 min later after the first wave; 1960 Chilean tsunami reached Hilo, Hawaii with a maximum wave arriving 1 hour later with a height of 5m, first wave being only 1.2m. Largest later waves is a problem not only for local authorities both in terms of warning to the public and rescue efforts but also mislead the public thinking that it is safe to return shoreline or evacuated site after arrival of the first wave. Okal and Synolakis considered Hammack's (1972, Ph.D. Dissertation, Calif. Inst. Tech., 261 pp., Pasadena) linear dispersive analytical solution with a tsunami generation through an uplifting of a circular plug on the ocean floor. They performed parametric study for the radius of the plug and the depth of the ocean since these are the independent scaling lengths in the problem. They identified transition distance, as the second wave being larger, regarding the parameters of the problem. Here, we extend their analysis to an initial wave field with a finite crest length and, in addition, to a most common tsunami initial wave form of N-wave as presented by Tadepalli and Synolakis (1994, Proc. R. Soc. A: Math. Phys. Eng. Sci., 445, 99-112). We compare our results with non-dispersive linear shallow water wave results as presented by Kanoglu et al. (2013, Proc. R. Soc. A: Math. Phys. Eng. Sci., 469, 20130015), investigating focusing feature. We discuss the results both in terms of leading wave amplitude and tsunami focusing. Acknowledgment: The research leading to these results has received funding from the European Union's Seventh Framework Programme (FP7/2007-2013) under grant agreement no 603839 (Project ASTARTE - Assessment, Strategy and Risk </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017JGRD..122.5076L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017JGRD..122.5076L">Tsunami-driven gravity waves in the presence of vertically varying background and tidal wind structures</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Laughman, B.; Fritts, D. C.; Lund, T. S. 2017-05-01 Many characteristics of tsunami-driven gravity waves (TDGWs) enable them to easily propagate into the thermosphere and ionosphere with appreciable amplitudes capable of producing detectable perturbations in electron densities and total electron content. The impact of vertically varying background and tidal wind structures on TDGW propagation is investigated with a series of idealized background wind profiles to assess the relative importance of wave reflection, critical-level approach, and dissipation. These numerical simulations employ a 2-D nonlinear anelastic finite-volume neutral atmosphere model which accounts for effects accompanying vertical gravity wave (GW) propagation such as amplitude growth with altitude. The GWs are excited by an idealized tsunami forcing with a 50 cm sea surface displacement, a 400 km horizontal wavelength, and a phase speed of 200 ms-1 consistent with previous studies of the tsunami generated by the 26 December 2004 Sumatra earthquake. Results indicate that rather than partial reflection and trapping, the dominant process governing TDGW propagation to thermospheric altitudes is refraction to larger and smaller vertical scales, resulting in respectively larger and smaller vertical group velocities and respectively reduced and increased viscous dissipation. Under all considered background wind profiles, TDGWs were able to attain ionospheric altitudes with appreciable amplitudes. Finally, evidence of nonlinear effects is observed and the conditions leading to their formation is discussed. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012AGUFMOS11C1651A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012AGUFMOS11C1651A">Errors in Tsunami Source Estimation from Tide Gauges</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Arcas, D. 2012-12-01 Linearity of tsunami waves in deep water can be assessed as a comparison of flow speed, u to wave propagation speed √gh. In real tsunami scenarios this evaluation becomes impractical due to the absence of observational data of tsunami flow velocities in shallow water. Consequently the extent of validity of the linear regime in the ocean is unclear. Linearity is the fundamental assumption behind tsunami source inversion processes based on linear combinations of unit propagation runs from a deep water propagation database (Gica et al., 2008). The primary tsunami elevation data for such inversion is usually provided by National Oceanic and Atmospheric (NOAA) deep-water tsunami detection systems known as DART. The use of tide gauge data for such inversions is more controversial due to the uncertainty of wave linearity at the depth of the tide gauge site. This study demonstrates the inaccuracies incurred in source estimation using tide gauge data in conjunction with a linear combination procedure for tsunami source estimation. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2005AGUFM.S51D1034L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2005AGUFM.S51D1034L">High-Performance Computing and Visualization of Tsunamis and Wind-Driven Waves</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Liu, Y. S.; Zhang, H.; Yuen, D. A.; Wang, M. 2005-12-01 The Sumatran earthquake and the tsunami waves produced have awakened great scientific interest in wave-propagation over undulated bottom topography and along complicated coastlines. The recent hurricane Katrina has also called our attention to shorter period waves near the coast. Analytical approximations are valid over long wavelengths in the far field. For near field regions with complex geography and other complications, such as islands and harbors, numerical simulations must be employed to obtain accurate predictions in time and space. Nowadays using 10**7 to 10**8 grid points become quite routine with massively parallel computers and large RAM and disk memories. Besides tsunamis, river discharges from upstream events and waves driven by hurricanes are also of societal relevance, especially in central China and now also in U.S.A. Using automatic grid generation methods, we have devised a finite-element based code, for the three stages which culminates with the use of the augmented Lagrangian method for the run-up process, as well as the Arbitrary Lagrange- Euler Configuration method to tackle the free surface problem near the seashore. This formulation allows for the wave surface to be self-consistently determined within a linearized framework and is computationally very fast. Our continuous efforts are focussed on seeking novel algorithms and state of art techniques, in order to unravel the mysteries associated with tsunami wave propagation and wind-driven waves in 3-D. We have cast the Navier-Stokes equations within the framework of a compressible model with an equation of state for sea-water. Our formulation allows the tracking and simulation of three stages , principally the formation, propagation and run-up stages of tsunami and waves coming ashore. The sequential version of this code can run on a workstation with 4 Gbyte memory less than 2 minutes per time step for one million grid points. This code has also been parallelized with MPI-2 and has good </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AGUFMNH53D..03B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUFMNH53D..03B">Applications of acoustic-gravity waves numerical modeling to tsunami signals observed by gravimetry satellites in very low orbit</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Brissaud, Q.; Garcia, R.; Sladen, A.; Martin, R.; Komatitsch, D. 2016-12-01 Acoustic and gravity waves propagating in planetary atmospheres have been studied intensively as markers of specific phenomena (tectonic events, explosions) or as contributors to atmosphere dynamics. To get a better understanding of the physics behind these dynamic processes, both acoustic and gravity waves propagation should be modeled in an attenuating and windy 3D atmosphere from the ground all the way to the upper thermosphere. Thus, in order to provide an efficient numerical tool at the regional or global scale we introduce a high-order finite-difference time domain (FDTD) approach that relies on the linearized compressible Navier-Stokes equations with spatially non constant physical parameters (density, viscosities and speed of sound) and background velocities (wind). We present applications of these simulations to the propagation of gravity waves generated by tsunamis for realistic cases for which atmospheric models are extracted from empirical models including variations with altitude of atmospheric parameters, and tsunami forcing at the ocean surface is extracted from shallow water simulations. We describe the specific difficulties induced by the size of the simulation, the boundary conditions and the spherical geometry and compare the simulation outputs to data gathered by gravimetric satellites crossing gravity waves generated by tsunamis. </li> <li> <a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/21148986-tsunami-wave-submerged-breakwater-interaction','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/21148986-tsunami-wave-submerged-breakwater-interaction">On the tsunami wave-submerged breakwater interaction</a> <a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a> Filianoti, P.; Piscopo, R. The tsunami wave loads on a submerged rigid breakwater are inertial. It is the result arising from the simple calculation method here proposed, and it is confirmed by the comparison with results obtained by other researchers. The method is based on the estimate of the speed drop of the tsunami wave passing over the breakwater. The calculation is rigorous for a sinusoidal wave interacting with a rigid submerged obstacle, in the framework of the linear wave theory. This new approach gives a useful and simple tool for estimating tsunami loads on submerged breakwaters.An unexpected novelty come out from a workedmore » example: assuming the same wave height, storm waves are more dangerous than tsunami waves, for the safety against sliding of submerged breakwaters.« less </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013EGUGA..15.8859G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013EGUGA..15.8859G">Rapid inundation estimates at harbor scale using tsunami wave heights offshore simulation and Green's law approach</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Gailler, Audrey; Hébert, Hélène; Loevenbruck, Anne 2013-04-01 Improvements in the availability of sea-level observations and advances in numerical modeling techniques are increasing the potential for tsunami warnings to be based on numerical model forecasts. Numerical tsunami propagation and inundation models are well developed and have now reached an impressive level of accuracy, especially in locations such as harbors where the tsunami waves are mostly amplified. In the framework of tsunami warning under real-time operational conditions, the main obstacle for the routine use of such numerical simulations remains the slowness of the numerical computation, which is strengthened when detailed grids are required for the precise modeling of the coastline response on the scale of an individual harbor. In fact, when facing the problem of the interaction of the tsunami wavefield with a shoreline, any numerical simulation must be performed over an increasingly fine grid, which in turn mandates a reduced time step, and the use of a fully non-linear code. Such calculations become then prohibitively time-consuming, which is clearly unacceptable in the framework of real-time warning. Thus only tsunami offshore propagation modeling tools using a single sparse bathymetric computation grid are presently included within the French Tsunami Warning Center (CENALT), providing rapid estimation of tsunami wave heights in high seas, and tsunami warning maps at western Mediterranean and NE Atlantic basins scale. We present here a preliminary work that performs quick estimates of the inundation at individual harbors from these deep wave heights simulations. The method involves an empirical correction relation derived from Green's law, expressing conservation of wave energy flux to extend the gridded wave field into the harbor with respect to the nearby deep-water grid node. The main limitation of this method is that its application to a given coastal area would require a large database of previous observations, in order to define the empirical </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015JGRC..120.6865L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015JGRC..120.6865L">Impacts of tides on tsunami propagation due to potential Nankai Trough earthquakes in the Seto Inland Sea, Japan</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Lee, Han Soo; Shimoyama, Tomohisa; Popinet, Stéphane 2015-10-01 The impacts of tides on extreme tsunami propagation due to potential Nankai Trough earthquakes in the Seto Inland Sea (SIS), Japan, are investigated through numerical experiments. Tsunami experiments are conducted based on five scenarios that consider tides at four different phases, such as flood, high, ebb, and low tides. The probes that were selected arbitrarily in the Bungo and Kii Channels show less significant effects of tides on tsunami heights and the arrival times of the first waves than those that experience large tidal ranges in inner basins and bays of the SIS. For instance, the maximum tsunami height and the arrival time at Toyomaesi differ by more than 0.5 m and nearly 1 h, respectively, depending on the tidal phase. The uncertainties defined in terms of calculated maximum tsunami heights due to tides illustrate that the calculated maximum tsunami heights in the inner SIS with standing tides have much larger uncertainties than those of two channels with propagating tides. Particularly in Harima Nada, the uncertainties due to the impacts of tides are greater than 50% of the tsunami heights without tidal interaction. The results recommend simulate tsunamis together with tides in shallow water environments to reduce the uncertainties involved with tsunami modeling and predictions for tsunami hazards preparedness. This article was corrected on 26 OCT 2015. See the end of the full text for details. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016APS..DFDD14007P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016APS..DFDD14007P">Generation of realistic tsunami waves using a bottom-tilting wave maker</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Park, Yong Sung; Hwang, Jin Hwan 2016-11-01 Tsunamis have caused more than 260,000 human losses and 250 billion in damage worldwide in the last ten years. Observations made during 2011 Japan Tohoku Tsunami revealed that the commonly used waves (solitary waves) to model tsunamis are at least an order-of-magnitude shorter than the real tsunamis, which calls for re-evaluation of the current understanding of tsunamis. To prompt the required paradigm shift, a new wave generator, namely the bottom-tilting wave generator, has been developed at the University of Dundee. The wave tank is fitted with an adjustable slope and a bottom flap hinged at the beginning of the slope. By moving the bottom flap up and down, we can generate very long waves. Here we will report characteristics of waves generated by simple bottom motions, either moving it upward or downward from an initial displacement ending it being horizontal. Two parameters, namely the initial displacement of the bottom and the speed of the motion, determine characteristics of the generated waves. Wave amplitudes scale well with the volume flux of the displaced water. On the other hand, due to combined effects of nonlinearity and dispersion, wavelengths show more complicated relationship with the two bottom motion parameters. We will also demonstrate that by combining simple up and down motions, it is possible to generate waves resembling the one measured during 2011 tsunami. YSP acknowledges financial support from the Royal Society of Edinburgh through the Royal Society of Edinburgh and Scottish Government Personal Research Fellowship Co-Funded by the Marie-Curie Actions. </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_1");'>1</a></li> <li class="active">2</li> <li><a href="#" onclick='return showDiv("page_3");'>3</a></li> <li><a href="#" onclick='return showDiv("page_4");'>4</a></li> <li><a href="#" onclick='return showDiv("page_5");'>5</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> </div> <div id="page_3" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_1");'>1</a></li> <li><a href="#" onclick='return showDiv("page_2");'>2</a></li> <li class="active">3</li> <li><a href="#" onclick='return showDiv("page_4");'>4</a></li> <li><a href="#" onclick='return showDiv("page_5");'>5</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="41"> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014EGUGA..1615964M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014EGUGA..1615964M">Tsunami Generation and Propagation by 3D deformable Landslides and Application to Scenarios</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> McFall, Brian C.; Fritz, Hermann M. 2014-05-01 Tsunamis generated by landslides and volcano flank collapse account for some of the most catastrophic natural disasters recorded and can be particularly devastative in the near field region due to locally high wave amplitudes and runup. The events of 1958 Lituya Bay, 1963 Vajont reservoir, 1980 Spirit Lake, 2002 Stromboli and 2010 Haiti demonstrate the danger of tsunamis generated by landslides or volcano flank collapses. Unfortunately critical field data from these events is lacking. Source and runup scenarios based on real world events are physically modeled using generalized Froude similarity in the three dimensional NEES tsunami wave basin at Oregon State University. A novel pneumatic landslide tsunami generator (LTG) was deployed to simulate landslides with varying geometry and kinematics. The bathymetric and topographic scenarios tested with the LTG are the basin-wide propagation and runup, fjord, curved headland fjord and a conical island setting representing a landslide off an island or a volcano flank collapse. The LTG consists of a sliding box filled with 1,350 kg of landslide material which is accelerated by means of four pneumatic pistons down a 2H:1V slope. The landslide is launched from the sliding box and continues to accelerate by gravitational forces up to velocities of 5 m/s. The landslide Froude number at impact with the water is in the range 1 <F <4. Two different materials are used to simulate landslides to study the granulometry effects: naturally rounded river gravel and cobble mixtures. Water surface elevations are recorded by an array of resistance wave gauges. The landslide deformation is measured from above and underwater camera recordings. The landslide deposit is measured on the basin floor with a multiple transducer acoustic array (MTA). Landslide surface reconstruction and kinematics are determined with a stereo particle image velocimetry (PIV) system. Wave runup is recorded with resistance wave gauges along the slope and verified </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013AGUFMNH41B1723W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013AGUFMNH41B1723W">Tsunami Hockey</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Weinstein, S.; Becker, N. C.; Wang, D.; Fryer, G. J. 2013-12-01 An important issue that vexes tsunami warning centers (TWCs) is when to cancel a tsunami warning once it is in effect. Emergency managers often face a variety of pressures to allow the public to resume their normal activities, but allowing coastal populations to return too quickly can put them at risk. A TWC must, therefore, exercise caution when cancelling a warning. Kim and Whitmore (2013) show that in many cases a TWC can use the decay of tsunami oscillations in a harbor to forecast when its amplitudes will fall to safe levels. This technique should prove reasonably robust for local tsunamis (those that are potentially dangerous within only 100 km of their source region) and for regional tsunamis (whose danger is limited to within 1000km of the source region) as well. For ocean-crossing destructive tsunamis such as the 11 March 2011 Tohoku tsunami, however, this technique may be inadequate. When a tsunami propagates across the ocean basin, it will encounter topographic obstacles such as seamount chains or coastlines, resulting in coherent reflections that can propagate great distances. When these reflections reach previously-impacted coastlines, they can recharge decaying tsunami oscillations and make them hazardous again. Warning center scientists should forecast sea-level records for 24 hours beyond the initial tsunami arrival in order to observe any potential reflections that may pose a hazard. Animations are a convenient way to visualize reflections and gain a broad geographic overview of their impacts. The Pacific Tsunami Warning Center has developed tools based on tsunami simulations using the RIFT tsunami forecast model. RIFT is a linear, parallelized numerical tsunami propagation model that runs very efficiently on a multi-CPU system (Wang et al, 2012). It can simulate 30-hours of tsunami wave propagation in the Pacific Ocean at 4 arc minute resolution in approximately 6 minutes of real time on a 12-CPU system. Constructing a 30-hour animation using 1 </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AGUFMNH43B1863G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUFMNH43B1863G">Development of new tsunami detection algorithms for high frequency radars and application to tsunami warning in British Columbia, Canada</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Grilli, S. T.; Guérin, C. A.; Shelby, M. R.; Grilli, A. R.; Insua, T. L.; Moran, P., Jr. 2016-12-01 A High-Frequency (HF) radar was installed by Ocean Networks Canada in Tofino, BC, to detect tsunamis from far- and near-field seismic sources; in particular, from the Cascadia Subduction Zone. This HF radar can measure ocean surface currents up to a 70-85 km range, depending on atmospheric conditions, based on the Doppler shift they cause in ocean waves at the Bragg frequency. In earlier work, we showed that tsunami currents must be at least 0.15 m/s to be directly detectable by a HF radar, when considering environmental noise and background currents (from tide/mesoscale circulation). This limits a direct tsunami detection to shallow water areas where currents are sufficiently strong due to wave shoaling and, hence, to the continental shelf. It follows that, in locations with a narrow shelf, warning times using a direct inversion method will be small. To detect tsunamis in deeper water, beyond the continental shelf, we proposed a new algorithm that does not require directly inverting currents, but instead is based on observing changes in patterns of spatial correlations of the raw radar signal between two radar cells located along the same wave ray, after time is shifted by the tsunami propagation time along the ray. A pattern change will indicate the presence of a tsunami. We validated this new algorithm for idealized tsunami wave trains propagating over a simple seafloor geometry in a direction normally incident to shore. Here, we further develop, extend, and validate the algorithm for realistic case studies of seismic tsunami sources impacting Vancouver Island, BC. Tsunami currents, computed with a state-of-the-art long wave model are spatially averaged over cells aligned along individual wave rays, located within the radar sweep area, obtained by solving the wave geometric optic equation; for long waves, such rays and tsunami propagation times along those are only function of the seafloor bathymetry, and hence can be precalculated for different incident tsunami </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013EGUGA..15.7776B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013EGUGA..15.7776B">Advanced Simulation of Coupled Earthquake and Tsunami Events</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Behrens, Joern 2013-04-01 Tsunami-Earthquakes represent natural catastrophes threatening lives and well-being of societies in a solitary and unexpected extreme event as tragically demonstrated in Sumatra (2004), Samoa (2009), Chile (2010), or Japan (2011). Both phenomena are consequences of the complex system of interactions of tectonic stress, fracture mechanics, rock friction, rupture dynamics, fault geometry, ocean bathymetry, and coastline geometry. The ASCETE project forms an interdisciplinary research consortium that couples the most advanced simulation technologies for earthquake rupture dynamics and tsunami propagation to understand the fundamental conditions of tsunami generation. We report on the latest research results in physics-based dynamic rupture and tsunami wave propagation simulation, using unstructured and adaptive meshes with continuous and discontinuous Galerkin discretization approaches. Coupling both simulation tools - the physics-based dynamic rupture simulation and the hydrodynamic tsunami wave propagation - will give us the possibility to conduct highly realistic studies of the interaction of rupture dynamics and tsunami impact characteristics. </li> <li> <a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=3650&hterms=worlds+oceans&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Dworlds%2Boceans','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=3650&hterms=worlds+oceans&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Dworlds%2Boceans">Deep Ocean Tsunami Waves off the Sri Lankan Coast</a> <a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a> 2004-01-01 fully understand the dynamics. Examination of other MISR images of this area, taken under similar illumination conditions, has not uncovered any surface patterns resembling those seen here. This image is an example of how MISR's multi-angular capability provides unique information for understanding how tsunamis propagate. Another application of MISR data enabled scientists to measure the motion of breaking tsunami waves along the eastern shores of Andhra Pradesh, India. The Multi-angle Imaging SpectroRadiometer observes the daylit Earth continuously and every 9 days views the entire globe between 82 degrees North and 82 degrees South latitude. These data products were generated from a portion of the imagery acquired during Terra orbit 26720 and utilize data from within blocks 85 to 86 within World Reference System-2 path 142. MISR was built and is managed by NASA's Jet Propulsion Laboratory, Pasadena, CA, for NASA's Office of Earth Science, Washington, DC. The Terra satellite is managed by NASA's Goddard Space Flight Center, Greenbelt, MD. Image courtesy NASA/GSFC/LaRC/JPL, MISR Team. Text by Clare Averill (Raytheon ITSS/JPL); Michael Garay and David J. Diner (JPL, California Institute of Technology); and Vasily Titov (NOAA/Pacific Marine Environmental Laboratory and University of Washington/Joint Institute for the Study of the Atmosphere and Oceans). </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015GeoRL..42.4736M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015GeoRL..42.4736M">A new physics-based modeling approach for tsunami-ionosphere coupling</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Meng, X.; Komjathy, A.; Verkhoglyadova, O. P.; Yang, Y.-M.; Deng, Y.; Mannucci, A. J. 2015-06-01 Tsunamis can generate gravity waves propagating upward through the atmosphere, inducing total electron content (TEC) disturbances in the ionosphere. To capture this process, we have implemented tsunami-generated gravity waves into the Global Ionosphere-Thermosphere Model (GITM) to construct a three-dimensional physics-based model WP (Wave Perturbation)-GITM. WP-GITM takes tsunami wave properties, including the wave height, wave period, wavelength, and propagation direction, as inputs and time-dependently characterizes the responses of the upper atmosphere between 100 km and 600 km altitudes. We apply WP-GITM to simulate the ionosphere above the West Coast of the United States around the time when the tsunami associated with the March 2011 Tohuku-Oki earthquke arrived. The simulated TEC perturbations agree with Global Positioning System observations reasonably well. For the first time, a fully self-consistent and physics-based model has reproduced the GPS-observed traveling ionospheric signatures of an actual tsunami event. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFMNH23A0256Y','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFMNH23A0256Y">Ocean-bottom pressure changes above a fault area for tsunami excitation and propagation observed by a submarine dense network</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Yomogida, K.; Saito, T. 2017-12-01 Conventional tsunami excitation and propagation have been formulated by incompressible fluid with velocity components. This approach is valid in most cases because we usually analyze tunamis as "long gravity waves" excited by submarine earthquakes. Newly developed ocean-bottom tsunami networks such as S-net and DONET have dramatically changed the above situation for the following two reasons: (1) tsunami propagations are now directly observed in a 2-D array manner without being suffered by complex "site effects" of sea shore, and (2) initial tsunami features can be directly detected just above a fault area. Removing the incompressibility assumption of sea water, we have formulated a new representation of tsunami excitation based on not velocity but displacement components. As a result, not only dynamics but static term (i.e., the component of zero frequency) can be naturally introduced, which is important for the pressure observed on the ocean floor, which ocean-bottom tsunami stations are going to record. The acceleration on the ocean floor should be combined with the conventional tsunami height (that is, the deformation of the sea level above a given station) in the measurement of ocean-bottom pressure although the acceleration exists only during fault motions in time. The M7.2 Off Fukushima earthquake on 22 November 2016 was the first event that excited large tsunamis within the territory of S-net stations. The propagation of tsunamis is found to be highly non-uniform, because of the strong velocity (i.e., sea depth) gradient perpendicular to the axis of Japan Trench. The earthquake was located in a shallow sea close to the coast, so that all the tsunami energy is reflected by the trench region of high velocity. Tsunami records (pressure gauges) within its fault area recorded clear slow motions of tsunamis (i.e., sea level changes) but also large high-frequency signals, as predicted by our theoretical result. That is, it may be difficult to extract tsunami </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012AGUFMSA33B..04T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012AGUFMSA33B..04T">Earthquake- and tsunami-induced ionospheric disturbances detected by GPS total electron content observation</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Tsugawa, T.; Nishioka, M.; Matsumura, M.; Shinagawa, H.; Maruyama, T.; Ogawa, T.; Saito, A.; Otsuka, Y.; Nagatsuma, T.; Murata, T. 2012-12-01 Ionospheric disturbances induced by the 2011 Tohoku earthquake and tsunami were studied by the high-resolution GPS total electron content (TEC) observation in Japan and in the world. The initial ionospheric disturbance appeared as sudden depletions by about 6 TEC unit (20%) about seven minutes after the earthquake onset, near the epicenter. From 06:00UT to 06:15UT, circular waves with short propagation distance propagated in the radial direction in the propagation velocity of 3,457, 783, 423 m/s for the first, second, third peak, respectively. Following these waves, concentric waves with long propagation distance appeared to propagate at the velocity of 138-288 m/s. In the vicinity of the epicenter, shortperiod oscillations with period of about 4 minutes were observed after 06:00 UT for 3 hours or more. We focus on the the circular and concentric waves in this paper. The circular or concentric structures indicate that these ionospheric disturbances had a point source. The center of these structures, termed as "ionospheric epicenter", was located around 37.5 deg N of latitude and 144.0 deg E of longitude, 170 km far from the epicenter to the southeast direction, and corresponded to the tsunami source. Comparing to the results of a numerical simulation using non-hydrostatic compressible atmosphere-ionosphere model, the first peak of circular wave would be caused by the acoustic waves generated from the propagating Rayleigh wave. The second and third waves would be caused by atmospheric gravity waves excited in the lower ionosphere due to the acoustic wave propagations from the tsunami source. The fourth and following waves are considered to be caused by the atmospheric gravity waves induced by the wavefronts of traveling tsunami. Long-propagation of these TEC disturbances were studied also using high-resolution GPS-TEC data in North America and Europe. Medium-scale wave structures with wavelengths of several 100 km appeared in the west part of North America at the </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AGUFMNH43B1857M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUFMNH43B1857M">Modeling Tsunami Wave Generation Using a Two-layer Granular Landslide Model</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Ma, G.; Kirby, J. T., Jr.; Shi, F.; Grilli, S. T.; Hsu, T. J. 2016-12-01 Tsunamis can be generated by subaerial or submarine landslides in reservoirs, lakes, fjords, bays and oceans. Compared to seismogenic tsunamis, landslide or submarine mass failure (SMF) tsunamis are normally characterized by relatively shorter wave lengths and stronger wave dispersion, and potentially may generate large wave amplitudes locally and high run-up along adjacent coastlines. Due to a complex interplay between the landslide and tsunami waves, accurate simulation of landslide motion as well as tsunami generation is a challenging task. We develop and test a new two-layer model for granular landslide motion and tsunami wave generation. The landslide is described as a saturated granular flow, accounting for intergranular stresses governed by Coulomb friction. Tsunami wave generation is simulated by the three-dimensional non-hydrostatic wave model NHWAVE, which is capable of capturing wave dispersion efficiently using a small number of discretized vertical levels. Depth-averaged governing equations for the granular landslide are derived in a slope-oriented coordinate system, taking into account the dynamic interaction between the lower-layer granular landslide and upper-layer water motion. The model is tested against laboratory experiments on impulsive wave generation by subaerial granular landslides. Model results illustrate a complex interplay between the granular landslide and tsunami waves, and they reasonably predict not only the tsunami wave generation but also the granular landslide motion from initiation to deposition. </li> <li> <a target="_blank" onclick="trackOutboundLink('https://pubs.usgs.gov/of/2013/1170/d/pdf/of2013-1170d.pdf','USGSPUBS'); return false;" href="https://pubs.usgs.gov/of/2013/1170/d/pdf/of2013-1170d.pdf">Modeling for the SAFRR Tsunami Scenario-generation, propagation, inundation, and currents in ports and harbors: Chapter D in The SAFRR (Science Application for Risk Reduction) Tsunami Scenario</a> <a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a> , 2013-01-01 locales in southern California. Importantly, section 6 provides a comparison of the effect of including horizontal displacements at the source described in section 1 and differences in bottom friction on wave heights and inundation in the Ports of Los Angeles and Long Beach. Modeling described in section 7 (Lynett and Son) uses a higher order physical model to determine variations of currents during the tsunami and complex flow structures such as jets and eddies. Section 7 also uses sediment transport models to estimate scour and deposition of sediment in ports and harbors—a significant effect that was observed in southern California following the 2011 Tohoku tsunami. Together, all of the sections in this report form the basis for damage, impact, and emergency preparedness aspects of the SAFRR tsunami scenario. Three sections of this report independently calculate wave height and inundation results using the source specified by Kirby and others (2013). Refer to figure 29 in section 3, figure 52 in section 4, and figure 62 in section 6. All of these results are relative to a mean high water (MHW) vertical datum. Slight differences in the results are observed in East Basin of the Port of Los Angeles, Alamitos Bay, and the Seal Beach National Wildlife Refuge. However, given that these three modeling efforts involved different implementations of the source, different numerical wave propagation and runup models, and slight differences in the digital elevation models (DEMs), the similarity among the results is remarkable. </li> <li> <a target="_blank" onclick="trackOutboundLink('https://images.nasa.gov/#/details-vger.html','SCIGOVIMAGE-NASA'); return false;" href="https://images.nasa.gov/#/details-vger.html">Voyager 1: Three "Tsunami Waves" in Interstellar Space</a> <a target="_blank" href="https://images.nasa.gov/">NASA Image and Video Library</a> 2017-03-22 Voyager 1: Three "Tsunami Waves" in Interstellar Space. The Voyager 1 spacecraft has experienced three "tsunami waves" in interstellar space. Listen to how these waves cause surrounding ionized matter to ring. More details on this sound can be found here: www.nasa.gov/jpl/nasa-voyager-t…nterstellar-space/ </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFMNH23A0202N','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFMNH23A0202N">A rapid calculation system for tsunami propagation in Japan by using the AQUA-MT/CMT solutions</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Nakamura, T.; Suzuki, W.; Yamamoto, N.; Kimura, H.; Takahashi, N. 2017-12-01 We developed a rapid calculation system of geodetic deformations and tsunami propagation in and around Japan. The system automatically conducts their forward calculations by using point source parameters estimated by the AQUA system (Matsumura et al., 2006), which analyze magnitude, hypocenter, and moment tensors for an event occurring in Japan in 3 minutes of the origin time at the earliest. An optimized calculation code developed by Nakamura and Baba (2016) is employed for the calculations on our computer server with 12 core processors of Intel Xeon 2.60 GHz. Assuming a homogeneous fault slip in the single fault plane as the source fault, the developed system calculates each geodetic deformation and tsunami propagation by numerically solving the 2D linear long-wave equations for the grid interval of 1 arc-min from two fault orientations simultaneously; i.e., one fault and its conjugate fault plane. Because fault models based on moment tensor analyses of event data are used, the system appropriately evaluate tsunami propagation even for unexpected events such as normal faulting in the subduction zone, which differs with the evaluation of tsunami arrivals and heights from a pre-calculated database by using fault models assuming typical types of faulting in anticipated source areas (e.g., Tatehata, 1998; Titov et al., 2005; Yamamoto et al., 2016). By the complete automation from event detection to output graphical figures, the calculation results can be available via e-mail and web site in 4 minutes of the origin time at the earliest. For moderate-sized events such as M5 to 6 events, the system helps us to rapidly investigate whether amplitudes of tsunamis at nearshore and offshore stations exceed a noise level or not, and easily identify actual tsunamis at the stations by comparing with obtained synthetic waveforms. In the case of using source models investigated from GNSS data, such evaluations may be difficult because of the low resolution of sources due to a low </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017EP%26S...69..117L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017EP%26S...69..117L">Should tsunami simulations include a nonzero initial horizontal velocity?</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Lotto, Gabriel C.; Nava, Gabriel; Dunham, Eric M. 2017-08-01 Tsunami propagation in the open ocean is most commonly modeled by solving the shallow water wave equations. These equations require initial conditions on sea surface height and depth-averaged horizontal particle velocity or, equivalently, horizontal momentum. While most modelers assume that initial velocity is zero, Y.T. Song and collaborators have argued for nonzero initial velocity, claiming that horizontal displacement of a sloping seafloor imparts significant horizontal momentum to the ocean. They show examples in which this effect increases the resulting tsunami height by a factor of two or more relative to models in which initial velocity is zero. We test this claim with a "full-physics" integrated dynamic rupture and tsunami model that couples the elastic response of the Earth to the linearized acoustic-gravitational response of a compressible ocean with gravity; the model self-consistently accounts for seismic waves in the solid Earth, acoustic waves in the ocean, and tsunamis (with dispersion at short wavelengths). Full-physics simulations of subduction zone megathrust ruptures and tsunamis in geometries with a sloping seafloor confirm that substantial horizontal momentum is imparted to the ocean. However, almost all of that initial momentum is carried away by ocean acoustic waves, with negligible momentum imparted to the tsunami. We also compare tsunami propagation in each simulation to that predicted by an equivalent shallow water wave simulation with varying assumptions regarding initial velocity. We find that the initial horizontal velocity conditions proposed by Song and collaborators consistently overestimate the tsunami amplitude and predict an inconsistent wave profile. Finally, we determine tsunami initial conditions that are rigorously consistent with our full-physics simulations by isolating the tsunami waves from ocean acoustic and seismic waves at some final time, and backpropagating the tsunami waves to their initial state by solving the </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2007NHESS...7..741D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2007NHESS...7..741D">Tsunami propagation modelling - a sensitivity study</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Dao, M. H.; Tkalich, P. 2007-12-01 Indian Ocean (2004) Tsunami and following tragic consequences demonstrated lack of relevant experience and preparedness among involved coastal nations. After the event, scientific and forecasting circles of affected countries have started a capacity building to tackle similar problems in the future. Different approaches have been used for tsunami propagation, such as Boussinesq and Nonlinear Shallow Water Equations (NSWE). These approximations were obtained assuming different relevant importance of nonlinear, dispersion and spatial gradient variation phenomena and terms. The paper describes further development of original TUNAMI-N2 model to take into account additional phenomena: astronomic tide, sea bottom friction, dispersion, Coriolis force, and spherical curvature. The code is modified to be suitable for operational forecasting, and the resulting version (TUNAMI-N2-NUS) is verified using test cases, results of other models, and real case scenarios. Using the 2004 Tsunami event as one of the scenarios, the paper examines sensitivity of numerical solutions to variation of different phenomena and parameters, and the results are analyzed and ranked accordingly. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016PApGe.173.3895G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016PApGe.173.3895G">Tsunami Detection by High-Frequency Radar Beyond the Continental Shelf</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Grilli, Stéphan T.; Grosdidier, Samuel; Guérin, Charles-Antoine 2016-12-01 Where coastal tsunami hazard is governed by near-field sources, such as submarine mass failures or meteo-tsunamis, tsunami propagation times may be too small for a detection based on deep or shallow water buoys. To offer sufficient warning time, it has been proposed to implement early warning systems relying on high-frequency (HF) radar remote sensing, that can provide a dense spatial coverage as far offshore as 200-300 km (e.g., for Diginext Ltd.'s Stradivarius radar). Shore-based HF radars have been used to measure nearshore currents (e.g., CODAR SeaSonde® system; http://www.codar.com/), by inverting the Doppler spectral shifts, these cause on ocean waves at the Bragg frequency. Both modeling work and an analysis of radar data following the Tohoku 2011 tsunami, have shown that, given proper detection algorithms, such radars could be used to detect tsunami-induced currents and issue a warning. However, long wave physics is such that tsunami currents will only rise above noise and background currents (i.e., be at least 10-15 cm/s), and become detectable, in fairly shallow water which would limit the direct detection of tsunami currents by HF radar to nearshore areas, unless there is a very wide shallow shelf. Here, we use numerical simulations of both HF radar remote sensing and tsunami propagation to develop and validate a new type of tsunami detection algorithm that does not have these limitations. To simulate the radar backscattered signal, we develop a numerical model including second-order effects in both wind waves and radar signal, with the wave angular frequency being modulated by a time-varying surface current, combining tsunami and background currents. In each "radar cell", the model represents wind waves with random phases and amplitudes extracted from a specified (wind speed dependent) energy density frequency spectrum, and includes effects of random environmental noise and background current; phases, noise, and background current are extracted from </li> <li> <a target="_blank" onclick="trackOutboundLink('http://dx.doi.org/10.1016/S0065-2687(09)05108-5','USGSPUBS'); return false;" href="http://dx.doi.org/10.1016/S0065-2687(09)05108-5">Chapter 3 – Phenomenology of Tsunamis: Statistical Properties from Generation to Runup</a> <a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a> Geist, Eric L. 2015-01-01 Observations related to tsunami generation, propagation, and runup are reviewed and described in a phenomenological framework. In the three coastal regimes considered (near-field broadside, near-field oblique, and far field), the observed maximum wave amplitude is associated with different parts of the tsunami wavefield. The maximum amplitude in the near-field broadside regime is most often associated with the direct arrival from the source, whereas in the near-field oblique regime, the maximum amplitude is most often associated with the propagation of edge waves. In the far field, the maximum amplitude is most often caused by the interaction of the tsunami coda that develops during basin-wide propagation and the nearshore response, including the excitation of edge waves, shelf modes, and resonance. Statistical distributions that describe tsunami observations are also reviewed, both in terms of spatial distributions, such as coseismic slip on the fault plane and near-field runup, and temporal distributions, such as wave amplitudes in the far field. In each case, fundamental theories of tsunami physics are heuristically used to explain the observations. </li> <li> <a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70148278','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70148278">Near-field tsunami edge waves and complex earthquake rupture</a> <a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a> Geist, Eric L. 2013-01-01 The effect of distributed coseismic slip on progressive, near-field edge waves is examined for continental shelf tsunamis. Detailed observations of edge waves are difficult to separate from the other tsunami phases that are observed on tide gauge records. In this study, analytic methods are used to compute tsunami edge waves distributed over a finite number of modes and for uniformly sloping bathymetry. Coseismic displacements from static elastic theory are introduced as initial conditions in calculating the evolution of progressive edge-waves. Both simple crack representations (constant stress drop) and stochastic slip models (heterogeneous stress drop) are tested on a fault with geometry similar to that of the M w = 8.8 2010 Chile earthquake. Crack-like ruptures that are beneath or that span the shoreline result in similar longshore patterns of maximum edge-wave amplitude. Ruptures located farther offshore result in reduced edge-wave excitation, consistent with previous studies. Introduction of stress-drop heterogeneity by way of stochastic slip models results in significantly more variability in longshore edge-wave patterns compared to crack-like ruptures for the same offshore source position. In some cases, regions of high slip that are spatially distinct will yield sub-events, in terms of tsunami generation. Constructive interference of both non-trapped and trapped waves can yield significantly larger tsunamis than those that produced by simple earthquake characterizations. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015PApGe.172.1679L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015PApGe.172.1679L">Advanced Tsunami Numerical Simulations and Energy Considerations by use of 3D-2D Coupled Models: The October 11, 1918, Mona Passage Tsunami</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> López-Venegas, Alberto M.; Horrillo, Juan; Pampell-Manis, Alyssa; Huérfano, Victor; Mercado, Aurelio 2015-06-01 The most recent tsunami observed along the coast of the island of Puerto Rico occurred on October 11, 1918, after a magnitude 7.2 earthquake in the Mona Passage. The earthquake was responsible for initiating a tsunami that mostly affected the northwestern coast of the island. Runup values from a post-tsunami survey indicated the waves reached up to 6 m. A controversy regarding the source of the tsunami has resulted in several numerical simulations involving either fault rupture or a submarine landslide as the most probable cause of the tsunami. Here we follow up on previous simulations of the tsunami from a submarine landslide source off the western coast of Puerto Rico as initiated by the earthquake. Improvements on our previous study include: (1) higher-resolution bathymetry; (2) a 3D-2D coupled numerical model specifically developed for the tsunami; (3) use of the non-hydrostatic numerical model NEOWAVE (non-hydrostatic evolution of ocean WAVE) featuring two-way nesting capabilities; and (4) comprehensive energy analysis to determine the time of full tsunami wave development. The three-dimensional Navier-Stokes model tsunami solution using the Navier-Stokes algorithm with multiple interfaces for two fluids (water and landslide) was used to determine the initial wave characteristic generated by the submarine landslide. Use of NEOWAVE enabled us to solve for coastal inundation, wave propagation, and detailed runup. Our results were in agreement with previous work in which a submarine landslide is favored as the most probable source of the tsunami, and improvement in the resolution of the bathymetry yielded inundation of the coastal areas that compare well with values from a post-tsunami survey. Our unique energy analysis indicates that most of the wave energy is isolated in the wave generation region, particularly at depths near the landslide, and once the initial wave propagates from the generation region its energy begins to stabilize. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018AcGeo.tmp...36A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018AcGeo.tmp...36A">Identifying the role of initial wave parameters on tsunami focusing</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Aydın, Baran 2018-04-01 Unexpected local tsunami amplification, which is referred to as tsunami focusing, is attributed to two different mechanisms: bathymetric features of the ocean bottom such as underwater ridges and dipolar shape of the initial wave itself. In this study, we characterize the latter; that is, we explore how amplitude and location of the focusing point vary with certain geometric parameters of the initial wave such as its steepness and crest length. Our results reveal two important features of tsunami focusing: for mild waves maximum wave amplitude increases significantly with transverse length of wave crest, while location of the focusing point is almost invariant. For steep waves, on the other hand, increasing crest length dislocates focusing point significantly, while it causes a rather small increase in wave maximum. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19890011928','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19890011928">Sedimentological effects of tsunamis, with particular reference to impact-generated and volcanogenic waves</a> <a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a> Bourgeois, Joanne; Wiberg, Patricia L. 1988-01-01 Impulse-generated waves (tsunamis) may be produced, at varying scales and global recurrence intervals (RI), by several processes. Meteorite-water impacts will produce tsunamis, and asteroid-scale impacts with associated mega-tsunamis may occur. A bolide-water impact would undoubtedly produce a major tsunami, whose sedimentological effects should be recognizable. Even a bolide-land impact might trigger major submarine landslides and thus tsunamis. In all posulated scenarios for the K/T boundary event, then, tsunamis are expected, and where to look for them must be determined, and how to distinguish deposits from different tsunamis. Also, because tsunamis decrease in height as they move away from their source, the proximal effects will differ by perhaps orders of magnitude from distal effects. Data on the characteristics of tsunamis at their origin are scarce. Some observations exist for tsunamis generated by thermonuclear explosions and for seismogenic tsunamis, and experimental work was conducted on impact-generated tsunamis. All tsunamis of interest have wave-lengths of 0(100) km and thus behave as shallow-water waves in all ocean depths. Typical wave periods are 0(10 to 100) minutes. The effect of these tsunamis can be estimated in the marine and coastal realm by calculating boundary shear stresses (expressed as U*, the shear velocity). An event layer at the K/T boundary in Texas occurs in mid-shelf muds. Only a large, long-period wave with a wave height of 0(50) m, is deemed sufficient to have produced this layer. Such wave heights imply a nearby volcanic explosion on the scale of Krakatau or larger, or a nearby submarine landslide also of great size, or a bolide-water impact in the ocean. </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_1");'>1</a></li> <li><a href="#" onclick='return showDiv("page_2");'>2</a></li> <li class="active">3</li> <li><a href="#" onclick='return showDiv("page_4");'>4</a></li> <li><a href="#" onclick='return showDiv("page_5");'>5</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> </div> <div id="page_4" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_2");'>2</a></li> <li><a href="#" onclick='return showDiv("page_3");'>3</a></li> <li class="active">4</li> <li><a href="#" onclick='return showDiv("page_5");'>5</a></li> <li><a href="#" onclick='return showDiv("page_6");'>6</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="61"> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AGUFMNH53D..04R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUFMNH53D..04R">Tsunami normal modes with solid earth and atmospheric coupling and inversion of the TEC data to estimate tsunami water height in the case of the Queen Charlotte tsunami.</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Rakoto, V.; Lognonne, P. H.; Rolland, L. 2016-12-01 Large underwater earthquakes (Mw > 7) can transmit part of their energy to the surrounding ocean through large sea-floor motions, generating tsunamis that propagate over long distances. The forcing effect of long period ocean surface vibrations due to tsunami waves on the atmosphere trigger atmospheric internal gravity waves (IGWs) that induce ionospheric disturbances when they reach the upper atmosphere. In this poster, we study the IGWs associated to tsunamis using a normal modes 1D modeling approach. Our model is first applied to the case of the October 2012 Haida Gwaii tsunami observed offshore Hawaii. We found three resonances between tsunami modes and the atmospheric gravity modes occurring around 1.5 mHz, 2 mHz and 2.5 mHz, with a large fraction of the energy of the tsunami modes transferred from the ocean to the atmosphere. At theses frequencies, the gravity branches are interacting with the tsunami one and have large amplitude in the ocean. As opposed to the tsunami, a fraction of their energy is therefore transferred from the atmosphere to the ocean. We also show that the fundamental of the gravity waves should arrive before the tsunami due to higher group velocity below 1.6 mHz. We demonstrate that only the 1.5 mHz resonance of the tsunami mode can trigger observable ionospheric perturbations, most often monitored using GPS dual-frequency measurements. Indeed, we show that the modes at 2 mHz and 2.5 mHz are already evanescent at the height of the F2 peak and have little energy in the ionosphere. This normal modes modeling offers a novel and comprehensive study of the transfer function from a propagating tsunami to the upper atmosphere. In particular, we can invert the perturbed TEC data induced by a tsunami in order to estimate the amplitude of the tsunami waveform using a least square method. This method has been performed in the case of the Haida Gwaii tsunami. The results showed a good agreement with the measurement of the dart buoy. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013AGUFMNH52A..04V','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013AGUFMNH52A..04V">CARIBE WAVE/LANTEX Caribbean and Western Atlantic Tsunami Exercises</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> von Hillebrandt-Andrade, C.; Whitmore, P.; Aliaga, B.; Huerfano Moreno, V. 2013-12-01 Over 75 tsunamis have been documented in the Caribbean and Adjacent Regions over the past 500 years. While most have been generated by local earthquakes, distant generated tsunamis can also affect the region. For example, waves from the 1755 Lisbon earthquake and tsunami were observed in Cuba, Dominican Republic, British Virgin Islands, as well as Antigua, Martinique, Guadalupe and Barbados in the Lesser Antilles. Since 1500, at least 4484 people are reported to have perished in these killer waves. Although the tsunami generated by the 2010 Haiti earthquake claimed only a few lives, in the 1530 El Pilar, Venezuela; 1602 Port Royale, Jamaica; 1918 Puerto Rico; and 1946 Samaná, Dominican Republic tsunamis the death tolls ranged to over a thousand. Since then, there has been an explosive increase in residents, visitors, infrastructure, and economic activity along the coastlines, increasing the potential for human and economic loss. It has been estimated that on any day, upwards of more than 500,000 people could be in harm's way just along the beaches, with hundreds of thousands more working and living in the tsunamis hazard zones. Given the relative infrequency of tsunamis, exercises are a valuable tool to test communications, evaluate preparedness and raise awareness. Exercises in the Caribbean are conducted under the framework of the UNESCO IOC Intergovernmental Coordination Group for the Tsunami and other Coastal Hazards Warning System for the Caribbean and Adjacent Regions (CARIBE EWS) and the US National Tsunami Hazard Mitigation Program. On March 23, 2011, 34 countries and territories participated in the first CARIBE WAVE/LANTEX regional tsunami exercise, while in the second exercise on March 20, 2013 a total of 45 countries and territories participated. 481 organizations (almost 200 more than in 2011) also registered to receive the bulletins issued by the Pacific Tsunami Warning Center (PTWC), West Coast and Alaska Tsunami Warning Center and/or the Puerto Rico </li> <li> <a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70017833','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70017833">Source parameters controlling the generation and propagation of potential local tsunamis along the cascadia margin</a> <a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a> Geist, E.; Yoshioka, S. 1996-01-01 The largest uncertainty in assessing hazards from local tsunamis along the Cascadia margin is estimating the possible earthquake source parameters. We investigate which source parameters exert the largest influence on tsunami generation and determine how each parameter affects the amplitude of the local tsunami. The following source parameters were analyzed: (1) type of faulting characteristic of the Cascadia subduction zone, (2) amount of slip during rupture, (3) slip orientation, (4) duration of rupture, (5) physical properties of the accretionary wedge, and (6) influence of secondary faulting. The effect of each of these source parameters on the quasi-static displacement of the ocean floor is determined by using elastic three-dimensional, finite-element models. The propagation of the resulting tsunami is modeled both near the coastline using the two-dimensional (x-t) Peregrine equations that includes the effects of dispersion and near the source using the three-dimensional (x-y-t) linear long-wave equations. The source parameters that have the largest influence on local tsunami excitation are the shallowness of rupture and the amount of slip. In addition, the orientation of slip has a large effect on the directivity of the tsunami, especially for shallow dipping faults, which consequently has a direct influence on the length of coastline inundated by the tsunami. Duration of rupture, physical properties of the accretionary wedge, and secondary faulting all affect the excitation of tsunamis but to a lesser extent than the shallowness of rupture and the amount and orientation of slip. Assessment of the severity of the local tsunami hazard should take into account that relatively large tsunamis can be generated from anomalous 'tsunami earthquakes' that rupture within the accretionary wedge in comparison to interplate thrust earthquakes of similar magnitude. ?? 1996 Kluwer Academic Publishers. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015EGUGA..17.4271R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015EGUGA..17.4271R">A Global Sensitivity Analysis Method on Maximum Tsunami Wave Heights to Potential Seismic Source Parameters</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Ren, Luchuan 2015-04-01 A Global Sensitivity Analysis Method on Maximum Tsunami Wave Heights to Potential Seismic Source Parameters Luchuan Ren, Jianwei Tian, Mingli Hong Institute of Disaster Prevention, Sanhe, Heibei Province, 065201, P.R. China It is obvious that the uncertainties of the maximum tsunami wave heights in offshore area are partly from uncertainties of the potential seismic tsunami source parameters. A global sensitivity analysis method on the maximum tsunami wave heights to the potential seismic source parameters is put forward in this paper. The tsunami wave heights are calculated by COMCOT ( the Cornell Multi-grid Coupled Tsunami Model), on the assumption that an earthquake with magnitude MW8.0 occurred at the northern fault segment along the Manila Trench and triggered a tsunami in the South China Sea. We select the simulated results of maximum tsunami wave heights at specific sites in offshore area to verify the validity of the method proposed in this paper. For ranking importance order of the uncertainties of potential seismic source parameters (the earthquake's magnitude, the focal depth, the strike angle, dip angle and slip angle etc..) in generating uncertainties of the maximum tsunami wave heights, we chose Morris method to analyze the sensitivity of the maximum tsunami wave heights to the aforementioned parameters, and give several qualitative descriptions of nonlinear or linear effects of them on the maximum tsunami wave heights. We quantitatively analyze the sensitivity of the maximum tsunami wave heights to these parameters and the interaction effects among these parameters on the maximum tsunami wave heights by means of the extended FAST method afterward. The results shows that the maximum tsunami wave heights are very sensitive to the earthquake magnitude, followed successively by the epicenter location, the strike angle and dip angle, the interactions effect between the sensitive parameters are very obvious at specific site in offshore area, and there </li> <li> <a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70156824','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70156824">Earthquake mechanism and seafloor deformation for tsunami generation</a> <a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a> Geist, Eric L.; Oglesby, David D.; Beer, Michael; Kougioumtzoglou, Ioannis A.; Patelli, Edoardo; Siu-Kui Au, Ivan 2014-01-01 Tsunamis are generated in the ocean by rapidly displacing the entire water column over a significant area. The potential energy resulting from this disturbance is balanced with the kinetic energy of the waves during propagation. Only a handful of submarine geologic phenomena can generate tsunamis: large-magnitude earthquakes, large landslides, and volcanic processes. Asteroid and subaerial landslide impacts can generate tsunami waves from above the water. Earthquakes are by far the most common generator of tsunamis. Generally, earthquakes greater than magnitude (M) 6.5–7 can generate tsunamis if they occur beneath an ocean and if they result in predominantly vertical displacement. One of the greatest uncertainties in both deterministic and probabilistic hazard assessments of tsunamis is computing seafloor deformation for earthquakes of a given magnitude. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20170005214','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20170005214">Asteroid Generated Tsunami Workshop: Summary of NASA/NOAA Workshop</a> <a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a> Morrison, David; Venkatapathy, Ethiraj 2017-01-01 A two-day workshop on tsunami generated by asteroid impacts in the ocean resulted in a broad consensus that the asteroid impact tsunami threat is not as great as previously thought, that airburst events in particular are unlikely to produce significant damage by tsunami, and that the tsunami contribution to the global ensemble impact hazard is substantially less than the contribution from land impacts. The workshop, led by Ethiraj Venkatapathy and David Morrison of NASA Ames, was organized into three sessions: 1) Near-field wave generation by the impact; 2) Long distance wave propagation; 3) Damage from coastal run-up and inundation, and associated hazard. Workshop approaches were to compare simulations to understand differences in the results and gain confidence in the modeling for both formation and propagation of tsunami from asteroid impacts, and to use this information for preliminary global risk assessment. The workshop focus was on smaller asteroids (diameter less than 250m), which represent the most frequent impacts. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2003EAEJA.....4971W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2003EAEJA.....4971W">Run-up of Tsunamis in the Gulf of Mexico caused by the Chicxulub Impact Event</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Weisz, R.; Wünnenmann, K.; Bahlburg, H. 2003-04-01 The Chicxulub impact event can be investigated on (1) local, (2) regional and in (3) global scales. Our investigations focus on the regional scale, especially on the run-up of tsunami waves on the coast around the Gulf of Mexico caused by the impact. An impact produces two types of tsunami waves: (1) the rim wave, (2) the collapse wave. Both waves propagate over long distances and reach coastal areas. Depending on the tsunami wave characteristics, they have a potentionally large influence on the coastal areas. Run-up distance and run-up height can be used as parameters for assessing this influence. To calculate these parameters, we are using a multi-material hydrocode (SALE) to simulate the generation of the tsunami wave, a non-linear shallow water approach for the propagation, and we implemented a special open boundary for considering the run-up of tsunami waves. With the help of the one-dimensional shallow water approach, we will give run-up heights and distances for the coastal area around the Gulf of Mexico. The calculations are done along several sections from the impact site towards the coast. These are a first approximation to run-up calculations for the entire coast of the Gulf of Mexico. The bathymetric data along the sections, used in the wave propagation and run-up, correspond to a linearized bathymetry of the recent Gulf of Mexico. Additionally, we will present preliminary results from our first two-dimensional experiments of propagation and run-up. These results will be compared with the one-dimensional approach. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015EGUGA..17.7622O','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015EGUGA..17.7622O">Sequencing of tsunami waves: Why the first wave is not always the largest</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Okal, Emile; Synolakis, Costas 2015-04-01 In many instances, the largest wave to hit a coastline during a tsunami is not the first one. Classical examples include the arrivals of the 1960 Chilean tsunami in Hilo, Hawaii, and of the 1964 Alaskan tsunami in Crescent City, California, where most casualties took place during later arrivals. This situation can be socially treacherous, since residents and civil defense authorities are led to believe that the worst is over after a first, relatively mild arrival, and to give an early "all clear" before the true largest wave, as was the case in Papeete, Tahiti during the 2011 Tohoku tsunami. We research this problem by using a number of simple models for which analytical solutions are available, as well as more realistic simulations of the large earthquake tsunamis of the past decade, and compare their results to a catalog of waveforms obtained at DART buoys spread over the Pacific Basin. Preliminary results indicate a transition from a regime of Maximum First Wave to one of Delayed Maximum when distance is increased, azimuth to receiver is moved away from the normal to fault strike, and/or source size is reduced. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013EGUGA..15.5562L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013EGUGA..15.5562L">Toward the Real-Time Tsunami Parameters Prediction</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Lavrentyev, Mikhail; Romanenko, Alexey; Marchuk, Andrey 2013-04-01 Today, a wide well-developed system of deep ocean tsunami detectors operates over the Pacific. Direct measurements of tsunami-wave time series are available. However, tsunami-warning systems fail to predict basic parameters of tsunami waves on time. Dozens examples could be provided. In our view, the lack of computational power is the main reason of these failures. At the same time, modern computer technologies such as, GPU (graphic processing unit) and FPGA (field programmable gates array), can dramatically improve data processing performance, which may enhance timely tsunami-warning prediction. Thus, it is possible to address the challenge of real-time tsunami forecasting for selected geo regions. We propose to use three new techniques in the existing tsunami warning systems to achieve real-time calculation of tsunami wave parameters. First of all, measurement system (DART buoys location, e.g.) should be optimized (both in terms of wave arriving time and amplitude parameter). The corresponding software application exists today and is ready for use [1]. We consider the example of the coastal line of Japan. Numerical tests show that optimal installation of only 4 DART buoys (accounting the existing sea bed cable) will reduce the tsunami wave detection time to only 10 min after an underwater earthquake. Secondly, as was shown by this paper authors, the use of GPU/FPGA technologies accelerates the execution of the MOST (method of splitting tsunami) code by 100 times [2]. Therefore, tsunami wave propagation over the ocean area 2000*2000 km (wave propagation simulation: time step 10 sec, recording each 4th spatial point and 4th time step) could be calculated at: 3 sec with 4' mesh 50 sec with 1' mesh 5 min with 0.5' mesh The algorithm to switch from coarse mesh to the fine grain one is also available. Finally, we propose the new algorithm for tsunami source parameters determination by real-time processing the time series, obtained at DART. It is possible to approximate </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013EGUGA..15.3631M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013EGUGA..15.3631M">Towards a robust framework for Probabilistic Tsunami Hazard Assessment (PTHA) for local and regional tsunami in New Zealand</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Mueller, Christof; Power, William; Fraser, Stuart; Wang, Xiaoming 2013-04-01 Probabilistic Tsunami Hazard Assessment (PTHA) is conceptually closely related to Probabilistic Seismic Hazard Assessment (PSHA). The main difference is that PTHA needs to simulate propagation of tsunami waves through the ocean and cannot rely on attenuation relationships, which makes PTHA computationally more expensive. The wave propagation process can be assumed to be linear as long as water depth is much larger than the wave amplitude of the tsunami. Beyond this limit a non-linear scheme has to be employed with significantly higher algorithmic run times. PTHA considering far-field tsunami sources typically uses unit source simulations, and relies on the linearity of the process by later scaling and combining the wave fields of individual simulations to represent the intended earthquake magnitude and rupture area. Probabilistic assessments are typically made for locations offshore but close to the coast. Inundation is calculated only for significantly contributing events (de-aggregation). For local and regional tsunami it has been demonstrated that earthquake rupture complexity has a significant effect on the tsunami amplitude distribution offshore and also on inundation. In this case PTHA has to take variable slip distributions and non-linearity into account. A unit source approach cannot easily be applied. Rupture complexity is seen as an aleatory uncertainty and can be incorporated directly into the rate calculation. We have developed a framework that manages the large number of simulations required for local PTHA. As an initial case study the effect of rupture complexity on tsunami inundation and the statistics of the distribution of wave heights have been investigated for plate-interface earthquakes in the Hawke's Bay region in New Zealand. Assessing the probability that water levels will be in excess of a certain threshold requires the calculation of empirical cumulative distribution functions (ECDF). We compare our results with traditional estimates for </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFMNH22A..03N','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFMNH22A..03N">Should tsunami models use a nonzero initial condition for horizontal velocity?</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Nava, G.; Lotto, G. C.; Dunham, E. M. 2017-12-01 Tsunami propagation in the open ocean is most commonly modeled by solving the shallow water wave equations. These equations require two initial conditions: one on sea surface height and another on depth-averaged horizontal particle velocity or, equivalently, horizontal momentum. While most modelers assume that initial velocity is zero, Y.T. Song and collaborators have argued for nonzero initial velocity, claiming that horizontal displacement of a sloping seafloor imparts significant horizontal momentum to the ocean. They show examples in which this effect increases the resulting tsunami height by a factor of two or more relative to models in which initial velocity is zero. We test this claim with a "full-physics" integrated dynamic rupture and tsunami model that couples the elastic response of the Earth to the linearized acoustic-gravitational response of a compressible ocean with gravity; the model self-consistently accounts for seismic waves in the solid Earth, acoustic waves in the ocean, and tsunamis (with dispersion at short wavelengths). We run several full-physics simulations of subduction zone megathrust ruptures and tsunamis in geometries with a sloping seafloor, using both idealized structures and a more realistic Tohoku structure. Substantial horizontal momentum is imparted to the ocean, but almost all momentum is carried away in the form of ocean acoustic waves. We compare tsunami propagation in each full-physics simulation to that predicted by an equivalent shallow water wave simulation with varying assumptions regarding initial conditions. We find that the initial horizontal velocity conditions proposed by Song and collaborators consistently overestimate the tsunami amplitude and predict an inconsistent wave profile. Finally, we determine tsunami initial conditions that are rigorously consistent with our full-physics simulations by isolating the tsunami waves (from ocean acoustic and seismic waves) at some final time, and backpropagating the tsunami </li> <li> <a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4887769','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4887769">Physical modelling of tsunamis generated by three-dimensional deformable granular landslides on planar and conical island slopes</a> <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a> 2016-01-01 Tsunamis generated by landslides and volcanic island collapses account for some of the most catastrophic events recorded, yet critically important field data related to the landslide motion and tsunami evolution remain lacking. Landslide-generated tsunami source and propagation scenarios are physically modelled in a three-dimensional tsunami wave basin. A unique pneumatic landslide tsunami generator was deployed to simulate landslides with varying geometry and kinematics. The landslides were generated on a planar hill slope and divergent convex conical hill slope to study lateral hill slope effects on the wave characteristics. The leading wave crest amplitude generated on a planar hill slope is larger on average than the leading wave crest generated on a convex conical hill slope, whereas the leading wave trough and second wave crest amplitudes are smaller. Between 1% and 24% of the landslide kinetic energy is transferred into the wave train. Cobble landslides transfer on average 43% more kinetic energy into the wave train than corresponding gravel landslides. Predictive equations for the offshore propagating wave amplitudes, periods, celerities and lengths generated by landslides on planar and divergent convex conical hill slopes are derived, which allow an initial rapid tsunami hazard assessment. PMID:27274697 </li> <li> <a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27274697','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27274697">Physical modelling of tsunamis generated by three-dimensional deformable granular landslides on planar and conical island slopes.</a> <a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a> McFall, Brian C; Fritz, Hermann M 2016-04-01 Tsunamis generated by landslides and volcanic island collapses account for some of the most catastrophic events recorded, yet critically important field data related to the landslide motion and tsunami evolution remain lacking. Landslide-generated tsunami source and propagation scenarios are physically modelled in a three-dimensional tsunami wave basin. A unique pneumatic landslide tsunami generator was deployed to simulate landslides with varying geometry and kinematics. The landslides were generated on a planar hill slope and divergent convex conical hill slope to study lateral hill slope effects on the wave characteristics. The leading wave crest amplitude generated on a planar hill slope is larger on average than the leading wave crest generated on a convex conical hill slope, whereas the leading wave trough and second wave crest amplitudes are smaller. Between 1% and 24% of the landslide kinetic energy is transferred into the wave train. Cobble landslides transfer on average 43% more kinetic energy into the wave train than corresponding gravel landslides. Predictive equations for the offshore propagating wave amplitudes, periods, celerities and lengths generated by landslides on planar and divergent convex conical hill slopes are derived, which allow an initial rapid tsunami hazard assessment. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013AGUFMNH43A1726G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013AGUFMNH43A1726G">Rapid inundation estimates at harbor scale using tsunami wave heights offshore simulation and coastal amplification laws</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Gailler, A.; Loevenbruck, A.; Hebert, H. 2013-12-01 Numerical tsunami propagation and inundation models are well developed and have now reached an impressive level of accuracy, especially in locations such as harbors where the tsunami waves are mostly amplified. In the framework of tsunami warning under real-time operational conditions, the main obstacle for the routine use of such numerical simulations remains the slowness of the numerical computation, which is strengthened when detailed grids are required for the precise modeling of the coastline response of an individual harbor. Thus only tsunami offshore propagation modeling tools using a single sparse bathymetric computation grid are presently included within the French Tsunami Warning Center (CENALT), providing rapid estimation of tsunami warning at western Mediterranean and NE Atlantic basins scale. We present here a preliminary work that performs quick estimates of the inundation at individual harbors from these high sea forecasting tsunami simulations. The method involves an empirical correction based on theoretical amplification laws (either Green's or Synolakis laws). The main limitation is that its application to a given coastal area would require a large database of previous observations, in order to define the empirical parameters of the correction equation. As no such data (i.e., historical tide gage records of significant tsunamis) are available for the western Mediterranean and NE Atlantic basins, we use a set of synthetic mareograms, calculated for both fake and well-known historical tsunamigenic earthquakes in the area. This synthetic dataset is obtained through accurate numerical tsunami propagation and inundation modeling by using several nested bathymetric grids of increasingly fine resolution close to the shores (down to a grid cell size of 3m in some Mediterranean harbors). Non linear shallow water tsunami modeling performed on a single 2' coarse bathymetric grid are compared to the values given by time-consuming nested grids simulations (and </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1995PApGe.144..875I','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1995PApGe.144..875I">Field survey of the 1994 Mindoro Island, Philippines tsunami</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Imamura, Fumihiko; Synolakis, Costas E.; Gica, Edison; Titov, Vasily; Listanco, Eddie; Lee, Ho Jun 1995-09-01 This is a report of the field survey of the November 15, 1994 Mindoro Island, Philippines, tsunami generated by an earthquake ( M=7.0) with a strike-slip motion. We will report runup heights from 54 locations on Luzon, Mindoro and other smaller islands in the Cape Verde passage between Mindoro and Luzon. Most of the damage was concentrated along the northern coast of Mindoro. Runup height distribution ranged 3 4 m at the most severely damaged areas and 2 4 in neighboring areas. The tsunami-affected area was limited to within 10 km of the epicenter. The largest recorded runup value of 7.3 m was measured on the southwestern coast of Baco Island while a runup of 6.1 m was detected on its northern coastline. The earthquake and tsunami killed 62 people, injured 248 and destroyed 800 houses. As observed in other recent tsunami disasters, most of the casualties were children. Nearly all eyewitnesses interviewed described the first wave as a leading-depression wave. Eyewitnesses reported that the main direction of tsunami propagation was SW in Subaang Bay, SE in Wawa and Calapan, NE on Baco Island and N on Verde Island, suggesting that the tsunami source area was in the southern Pass of Verde Island and that the wave propagated rapidly in all directions. The fault plane extended offshore to the N of Mindoro Island, with its rupture originating S of Verde Island and propagating almost directly south to the inland of Mindoro, thereby accounting for the relatively limited damage area observed on the N of Mindoro. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010EGUGA..1215694Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010EGUGA..1215694Z">February 27, 2010 Chilean Tsunami in Pacific and its Arrival to North East Asia</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Zaytsev, Andrey; Pelinovsky, Eï¬M.; Yalciner, Ahmet C.; Ozer, Ceren; Chernov, Anton; Kostenko, Irina; Shevchenko, Georgy 2010-05-01 The outskirts of the fault plane broken by the strong earthquake on February 27, 2010 in Chili with a magnitude 8.8 at the 35km depth of 35.909°S, 72.733°W coordinates generated a moderate size tsunami. The initial amplitude of the tsunami source is not so high because of the major area of the plane was at land. The tsunami waves propagated far distances in South and North directions to East Asia and Wet America coasts. The waves are also recorded by several gauges in Pacific during its propagation and arrival to coastal areas. The recorded and observed amplitudes of tsunami waves are important for the potential effects with the threatening amplitudes. The event also showed that a moderate size tsunami can be effective even if it propagates far distances in any ocean or a marginal sea. The far east coasts of Russia at North East Asia (Sakhalin, Kuriles, Kamchatka) are one of the important source (i.e. November 15, 2006, Kuril Island Tsunami) and target (i.e. February, 27, 2010 Chilean tsunami) areas of the Pacific tsunamis. Many efforts have been spent for establishment of the monitoring system and assessment of tsunamis and development of the mitigation strategies against tsunamis and other hazards in the region. Development of the computer technologies provided the advances in data collection, transfer, and processing. Furthermore it also contributed new developments in computational tools and made the computer modeling to be an efficient tool in tsunami warning systems. In this study the tsunami numerical model NAMI DANCE Nested version is used. NAMI-DANCE solves Nonlinear form of Long Wave (Shallow water) equations (with or without dispersion) using finite difference model in nested grid domains from the source to target areas in multiprocessor hardware environment. It is applied to 2010 Chilean tsunami and its propagation and coastal behavior at far distances near Sakhalin, Kuril and Kamchatka coasts. The main tide gauge records used in this study are from </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AGUFMEP14B..07S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AGUFMEP14B..07S">Numerical Modelling of Tsunami Generated by Deformable Submarine Slides: Parameterisation of Slide Dynamics for Coupling to Tsunami Propagation Model</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Smith, R. C.; Collins, G. S.; Hill, J.; Piggott, M. D.; Mouradian, S. L. 2015-12-01 Numerical modelling informs risk assessment of tsunami generated by submarine slides; however, for large-scale slides modelling can be complex and computationally challenging. Many previous numerical studies have approximated slides as rigid blocks that moved according to prescribed motion. However, wave characteristics are strongly dependent on the motion of the slide and previous work has recommended that more accurate representation of slide dynamics is needed. We have used the finite-element, adaptive-mesh CFD model Fluidity, to perform multi-material simulations of deformable submarine slide-generated waves at real world scales for a 2D scenario in the Gulf of Mexico. Our high-resolution approach represents slide dynamics with good accuracy, compared to other numerical simulations of this scenario, but precludes tracking of wave propagation over large distances. To enable efficient modelling of further propagation of the waves, we investigate an approach to extract information about the slide evolution from our multi-material simulations in order to drive a single-layer wave propagation model, also using Fluidity, which is much less computationally expensive. The extracted submarine slide geometry and position as a function of time are parameterised using simple polynomial functions. The polynomial functions are used to inform a prescribed velocity boundary condition in a single-layer simulation, mimicking the effect the submarine slide motion has on the water column. The approach is verified by successful comparison of wave generation in the single-layer model with that recorded in the multi-material, multi-layer simulations. We then extend this approach to 3D for further validation of this methodology (using the Gulf of Mexico scenario proposed by Horrillo et al., 2013) and to consider the effect of lateral spreading. This methodology is then used to simulate a series of hypothetical submarine slide events in the Arctic Ocean (based on evidence of historic </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AGUFMNH43A1819G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUFMNH43A1819G">Multiple Solutions of Real-time Tsunami Forecasting Using Short-term Inundation Forecasting for Tsunamis Tool</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Gica, E. 2016-12-01 The Short-term Inundation Forecasting for Tsunamis (SIFT) tool, developed by NOAA Center for Tsunami Research (NCTR) at the Pacific Marine Environmental Laboratory (PMEL), is used in forecast operations at the Tsunami Warning Centers in Alaska and Hawaii. The SIFT tool relies on a pre-computed tsunami propagation database, real-time DART buoy data, and an inversion algorithm to define the tsunami source. The tsunami propagation database is composed of 50×100km unit sources, simulated basin-wide for at least 24 hours. Different combinations of unit sources, DART buoys, and length of real-time DART buoy data can generate a wide range of results within the defined tsunami source. For an inexperienced SIFT user, the primary challenge is to determine which solution, among multiple solutions for a single tsunami event, would provide the best forecast in real time. This study investigates how the use of different tsunami sources affects simulated tsunamis at tide gauge locations. Using the tide gauge at Hilo, Hawaii, a total of 50 possible solutions for the 2011 Tohoku tsunami are considered. Maximum tsunami wave amplitude and root mean square error results are used to compare tide gauge data and the simulated tsunami time series. Results of this study will facilitate SIFT users' efforts to determine if the simulated tide gauge tsunami time series from a specific tsunami source solution would be within the range of possible solutions. This study will serve as the basis for investigating more historical tsunami events and tide gauge locations. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AGUFMNH41A1742K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUFMNH41A1742K">Tsunami Focusing and Leading Amplitude</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Kanoglu, U. 2016-12-01 Tsunamis transform substantially through spatial and temporal spreading from their source region. This substantial spreading might result unique maximum tsunami wave heights which might be attributed to the source configuration, directivity, the waveguide structures of mid-ocean ridges and continental shelves, focusing and defocusing through submarine seamounts, random focusing due to small changes in bathymetry, dispersion, and, most likely, combination of some of these effects. In terms of the maximum tsunami wave height, after Okal and Synolakis (2016 Geophys. J. Int. 204, 719-735), it is clear that dispersion would be one of the reasons to drive the leading wave amplitude in a tsunami wave train. Okal and Synolakis (2016), referring to this phenomenon as sequencing -later waves in the train becoming higher than the leading one, considered Hammack's (1972, Ph.D. Dissertation, Calif. Inst. Tech., 261 pp) formalism, in addition to LeMéhauté and Wang's (1995 Water waves generated by underwater explosion, World Scientific, 367 pp), to evaluate linear dispersive tsunami propagation from a circular plug uplifted on an ocean of constant depth. They identified transition distance, as the second wave being larger, performing parametric study for the radius of the plug and the depth of the ocean. Here, we extend Okal and Synolakis' (2016) analysis to an initial wave field with a finite crest length and, in addition, to a most common tsunami initial wave form of N-wave (Tadepalli and Synolakis, 1994 Proc. R. Soc. A: Math. Phys. Eng. Sci. 445, 99-112). First, we investigate the focusing feature in the leading-depression side, which enhance tsunami wave height as presented by Kanoglu et al. (2013 Proc. R. Soc. A: Math. Phys. Eng. Sci. 469, 20130015). We then discuss the results in terms of leading wave amplitude presenting a parametric study and identify a simple relation for the transition distance. The solution presented here could be used to better analyze dispersive </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AGUFMNH23A1848V','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AGUFMNH23A1848V">Validation and Performance Comparison of Numerical Codes for Tsunami Inundation</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Velioglu, D.; Kian, R.; Yalciner, A. C.; Zaytsev, A. 2015-12-01 In inundation zones, tsunami motion turns from wave motion to flow of water. Modelling of this phenomenon is a complex problem since there are many parameters affecting the tsunami flow. In this respect, the performance of numerical codes that analyze tsunami inundation patterns becomes important. The computation of water surface elevation is not sufficient for proper analysis of tsunami behaviour in shallow water zones and on land and hence for the development of mitigation strategies. Velocity and velocity patterns are also crucial parameters and have to be computed at the highest accuracy. There are numerous numerical codes to be used for simulating tsunami inundation. In this study, FLOW 3D and NAMI DANCE codes are selected for validation and performance comparison. Flow 3D simulates linear and nonlinear propagating surface waves as well as long waves by solving three-dimensional Navier-Stokes (3D-NS) equations. FLOW 3D is used specificaly for flood problems. NAMI DANCE uses finite difference computational method to solve linear and nonlinear forms of shallow water equations (NSWE) in long wave problems, specifically tsunamis. In this study, these codes are validated and their performances are compared using two benchmark problems which are discussed in 2015 National Tsunami Hazard Mitigation Program (NTHMP) Annual meeting in Portland, USA. One of the problems is an experiment of a single long-period wave propagating up a piecewise linear slope and onto a small-scale model of the town of Seaside, Oregon. Other benchmark problem is an experiment of a single solitary wave propagating up a triangular shaped shelf with an island feature located at the offshore point of the shelf. The computed water surface elevation and velocity data are compared with the measured data. The comparisons showed that both codes are in fairly good agreement with each other and benchmark data. All results are presented with discussions and comparisons. The research leading to these </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_2");'>2</a></li> <li><a href="#" onclick='return showDiv("page_3");'>3</a></li> <li class="active">4</li> <li><a href="#" onclick='return showDiv("page_5");'>5</a></li> <li><a href="#" onclick='return showDiv("page_6");'>6</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> </div> <div id="page_5" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_3");'>3</a></li> <li><a href="#" onclick='return showDiv("page_4");'>4</a></li> <li class="active">5</li> <li><a href="#" onclick='return showDiv("page_6");'>6</a></li> <li><a href="#" onclick='return showDiv("page_7");'>7</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="81"> <li> <a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5627378','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5627378">Uncertainties in the 2004 Sumatra–Andaman source through nonlinear stochastic inversion of tsunami waves</a> <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a> Venugopal, M.; Roy, D.; Rajendran, K.; Guillas, S.; Dias, F. 2017-01-01 Numerical inversions for earthquake source parameters from tsunami wave data usually incorporate subjective elements to stabilize the search. In addition, noisy and possibly insufficient data result in instability and non-uniqueness in most deterministic inversions, which are barely acknowledged. Here, we employ the satellite altimetry data for the 2004 Sumatra–Andaman tsunami event to invert the source parameters. We also include kinematic parameters that improve the description of tsunami generation and propagation, especially near the source. Using a finite fault model that represents the extent of rupture and the geometry of the trench, we perform a new type of nonlinear joint inversion of the slips, rupture velocities and rise times with minimal a priori constraints. Despite persistently good waveform fits, large uncertainties in the joint parameter distribution constitute a remarkable feature of the inversion. These uncertainties suggest that objective inversion strategies should incorporate more sophisticated physical models of seabed deformation in order to significantly improve the performance of early warning systems. PMID:28989311 </li> <li> <a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28989311','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28989311">Uncertainties in the 2004 Sumatra-Andaman source through nonlinear stochastic inversion of tsunami waves.</a> <a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a> Gopinathan, D; Venugopal, M; Roy, D; Rajendran, K; Guillas, S; Dias, F 2017-09-01 Numerical inversions for earthquake source parameters from tsunami wave data usually incorporate subjective elements to stabilize the search. In addition, noisy and possibly insufficient data result in instability and non-uniqueness in most deterministic inversions, which are barely acknowledged. Here, we employ the satellite altimetry data for the 2004 Sumatra-Andaman tsunami event to invert the source parameters. We also include kinematic parameters that improve the description of tsunami generation and propagation, especially near the source. Using a finite fault model that represents the extent of rupture and the geometry of the trench, we perform a new type of nonlinear joint inversion of the slips, rupture velocities and rise times with minimal a priori constraints. Despite persistently good waveform fits, large uncertainties in the joint parameter distribution constitute a remarkable feature of the inversion. These uncertainties suggest that objective inversion strategies should incorporate more sophisticated physical models of seabed deformation in order to significantly improve the performance of early warning systems. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AGUFM.S52A..01B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUFM.S52A..01B">Chilean Tsunami Rocks the Ross Ice Shelf</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Bromirski, P. D.; Gerstoft, P.; Chen, Z.; Stephen, R. A.; Diez, A.; Arcas, D.; Wiens, D.; Aster, R. C.; Nyblade, A. 2016-12-01 The response of the Ross Ice Shelf (RIS) to the September 16, 2015 9.3 Mb Chilean earthquake tsunami (> 75 s period) and infragravity (IG) waves (50 - 300 s period) were recorded by a broadband seismic array deployed on the RIS from November 2014 to November 2015. The array included two linear transects, one approximately orthogonal to the shelf front extending 430 km southward toward the grounding zone, and an east-west transect spanning the RIS roughly parallel to the front about 100 km south of the ice edge (https://scripps.ucsd.edu/centers/iceshelfvibes/). Signals generated by both the tsunami and IG waves were recorded at all stations on floating ice, with little ocean wave-induced energy reaching stations on grounded ice. Cross-correlation and dispersion curve analyses indicate that tsunami and IG wave-generated signals propagate across the RIS at gravity wave speeds (about 70 m/s), consistent with coupled water-ice flexural-gravity waves propagating through the ice shelf from the north. Gravity wave excitation at periods > 100 s is continuously observed during the austral winter, providing mechanical excitation of the RIS throughout the year. Horizontal displacements are typically about 3 times larger than vertical displacements, producing extensional motions that could facilitate expansion of existing fractures. The vertical and horizontal spectra in the IG band attenuate exponentially with distance from the front. Tsunami model data are used to assess variability of excitation of the RIS by long period gravity waves. Substantial variability across the RIS roughly parallel to the front is observed, likely resulting from a combination of gravity wave amplitude variability along the front, signal attenuation, incident angle of the wave forcing at the front that depends on wave generation location as well as bathymetry under and north of the shelf, and water layer and ice shelf thickness and properties. </li> <li> <a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/22220724-propagation-sound-waves-through-spatially-homogeneous-smoothly-time-dependent-medium','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/22220724-propagation-sound-waves-through-spatially-homogeneous-smoothly-time-dependent-medium">Propagation of sound waves through a spatially homogeneous but smoothly time-dependent medium</a> <a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a> Hayrapetyan, A.G., E-mail: armen@physi.uni-heidelberg.de; Max-Planck-Institut für Kernphysik, Saupfercheckweg 1, D-69117 Heidelberg; Grigoryan, K.K. 2013-06-15 The propagation of sound through a spatially homogeneous but non-stationary medium is investigated within the framework of fluid dynamics. For a non-vortical fluid, especially, a generalized wave equation is derived for the (scalar) potential of the fluid velocity distribution in dependence of the equilibrium mass density of the fluid and the sound wave velocity. A solution of this equation for a finite transition period τ is determined in terms of the hypergeometric function for a phenomenologically realistic, sigmoidal change of the mass density and sound wave velocity. Using this solution, it is shown that the energy flux of the soundmore » wave is not conserved but increases always for the propagation through a non-stationary medium, independent of whether the equilibrium mass density is increased or decreased. It is found, moreover, that this amplification of the transmitted wave arises from an energy exchange with the medium and that its flux is equal to the (total) flux of the incident and the reflected wave. An interpretation of the reflected wave as a propagation of sound backward in time is given in close analogy to Feynman and Stueckelberg for the propagation of anti-particles. The reflection and transmission coefficients of sound propagating through a non-stationary medium is analyzed in more detail for hypersonic waves with transition periods τ between 15 and 200 ps as well as the transformation of infrasound waves in non-stationary oceans. -- Highlights: •Analytically exact study of sound propagation through a non-stationary medium. •Energy exchange between the non-stationary medium and the sound wave. •Transformation of hypersonic and ultrasound frequencies in non-stationary media. •Propagation of sound backward in time in close analogy to anti-particles. •Prediction of tsunamis both in spatially and temporally inhomogeneous oceans.« less </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFMNH23A0194A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFMNH23A0194A">Preliminary Hazard Assessment for Tectonic Tsunamis in the Eastern Mediterranean</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Aydin, B.; Bayazitoglu, O.; Sharghi vand, N.; Kanoglu, U. 2017-12-01 There are many critical industrial facilities such as energy production units and energy transmission lines along the southeast coast of Turkey. This region is also active on tourism, and agriculture and aquaculture production. There are active faults in the region, i.e. the Cyprus Fault, which extends along the Mediterranean basin in the east-west direction and connects to the Hellenic Arc. Both the Cyprus Fault and the Hellenic Arc are seismologically active and are capable of generating earthquakes with tsunamigenic potential. Even a small tsunami in the region could cause confusion as shown by the recent 21 July 2017 earthquake of Mw 6.6, which occurred in the Aegean Sea, between Bodrum, Turkey and Kos Island, Greece since region is not prepared for such an event. Moreover, the Mediterranean Sea is one of the most vulnerable regions against sea level rise due to global warming, according to the 5th Report of the Intergovernmental Panel on Climate Change. For these reasons, a marine hazard such as a tsunami can cause much worse damage than expected in the region (Kanoglu et al., Phil. Trans. R. Soc. A 373, 2015). Hence, tsunami hazard assessment is required for the region. In this study, we first characterize earthquakes which have potential to generate a tsunami in the Eastern Mediterranean. Such study is a prerequisite for regional tsunami mitigation studies. For fast and timely predictions, tsunami warning systems usually employ databases that store pre-computed tsunami propagation resulting from hypothetical earthquakes with pre-defined parameters. These pre-defined sources are called tsunami unit sources and they are linearly superposed to mimic a real event, since wave propagation is linear offshore. After investigating historical earthquakes along the Cyprus Fault and the Hellenic Arc, we identified tsunamigenic earthquakes in the Eastern Mediterranean and proposed tsunami unit sources for the region. We used the tsunami numerical model MOST (Titov et al </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010EGUGA..12.3021L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010EGUGA..12.3021L">Computerized Workstation for Tsunami Hazard Monitoring</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Lavrentiev-Jr, Mikhail; Marchuk, Andrey; Romanenko, Alexey; Simonov, Konstantin; Titov, Vasiliy 2010-05-01 We present general structure and functionality of the proposed Computerized Workstation for Tsunami Hazard Monitoring (CWTHM). The tool allows interactive monitoring of hazard, tsunami risk assessment, and mitigation - at all stages, from the period of strong tsunamigenic earthquake preparation to inundation of the defended coastal areas. CWTHM is a software-hardware complex with a set of software applications, optimized to achieve best performance on hardware platforms in use. The complex is calibrated for selected tsunami source zone(s) and coastal zone(s) to be defended. The number of zones (both source and coastal) is determined, or restricted, by available hardware resources. The presented complex performs monitoring of selected tsunami source zone via the Internet. The authors developed original algorithms, which enable detection of the preparation zone of the strong underwater earthquake automatically. For the so-determined zone the event time, magnitude and spatial location of tsunami source are evaluated by means of energy of the seismic precursors (foreshocks) analysis. All the above parameters are updated after each foreshock. Once preparing event is detected, several scenarios are forecasted for wave amplitude parameters as well as the inundation zone. Estimations include the lowest and the highest wave amplitudes and the least and the most inundation zone. In addition to that, the most probable case is calculated. In case of multiple defended coastal zones, forecasts and estimates can be done in parallel. Each time the simulated model wave reaches deep ocean buoys or tidal gauge, expected values of wave parameters and inundation zones are updated with historical events information and pre-calculated scenarios. The Method of Splitting Tsunami (MOST) software package is used for mathematical simulation. The authors suggest code acceleration for deep water wave propagation. As a result, performance is 15 times faster compared to MOST, original version </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AGUOSPO14B2759C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUOSPO14B2759C">Tsunami Defense Efforts at Samcheok Port, Korea</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Cho, Y. S. 2016-02-01 Tsunamis mainly triggered by impulsive undersea motions are long waves and can propagate a long distance. Thus, they can cause huge casualties not only neighboring countries but also distant countries. Recently, several devastating tsunamis have been occurred around the Pacific Ocean rim. Among them, the Great East Japan tsunami occurred on March 11, 2011 is probably recorded as one of the most destructive tsunamis during last several decades. The Tsunami killed more than 20,000 people (including missing people) and deprived of property damage of approximately 300 billion USD. The eastern coast of the Korean Peninsula has been attacked historically by unexpected tsunami events. These tsunamis were generated by undersea earthquakes occurred off the west coast of Japan. For example, the Central East Sea Tsunami occurred on May 26, 1983 killed 3 people and caused serious property damage at Samcheok Port located at the eastern coast of Korea. Thus, a defense plan against unexpected tsunami strikes is an essential task for the port authority to protect lives of human beings and port facilities. In this study, a master plan of tsunami defense is introduced at Samcheok Port. A tsunami hazard map is also made by employing both propagation and inundation models. Detailed defense efforts are described including the procedure of development of a tsunami hazard map. Keywords: tsunami, hazard map, run-up height, emergency action plan </li> <li> <a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26392614','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26392614">The meteorite impact-induced tsunami hazard.</a> <a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a> Wünnemann, K; Weiss, R 2015-10-28 When a cosmic object strikes the Earth, it most probably falls into an ocean. Depending on the impact energy and the depth of the ocean, a large amount of water is displaced, forming a temporary crater in the water column. Large tsunami-like waves originate from the collapse of the cavity in the water and the ejecta splash. Because of the far-reaching destructive consequences of such waves, an oceanic impact has been suggested to be more severe than a similar-sized impact on land; in other words, oceanic impacts may punch over their weight. This review paper summarizes the process of impact-induced wave generation and subsequent propagation, whether the wave characteristic differs from tsunamis generated by other classical mechanisms, and what methods have been applied to quantify the consequences of an oceanic impact. Finally, the impact-induced tsunami hazard will be evaluated by means of the Eltanin impact event. © 2015 The Author(s). </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2004AGUFMOS23B1315V','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2004AGUFMOS23B1315V">Pyroclastic Flow Generated Tsunami Waves Detected by CALIPSO Borehole Strainmeters at Soufriere Hills, Montserrat During Massive Dome Collapse: Numerical Simulations and Observations</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> van Boskirk, E. J.; Voight, B.; Watts, P.; Widiwijayanti, C.; Mattioli, G. S.; Elsworth, D.; Hidayat, D.; Linde, A.; Malin, P.; Neuberg, J.; Sacks, S.; Shalev, E.; Sparks, R. J.; Young, S. R. 2004-12-01 The July 12-13, 2003 eruption (dome collapse plus explosions) of Soufriere Hills Volcano in Montserrat, WI, is the largest historical lava dome collapse with ˜120 million cubic meters of the dome lost. Pyroclastic flows entered the sea at 18:00 AST 12 July at the Tar River Valley (TRV) and continued until the early hours of 13 July. Low-amplitude tsunamis were reported at Antigua and Guadaloupe soon after the dome collapse. At the time of eruption, four CALIPSO borehole-monitoring stations were in the process of being installed, and three very-broad-band Sacks-Evertson dilatometers were operational and recorded the event at 50 sps. The strongest strain signals were recorded at the Trants site, 5 km north of the TRV entry zone, suggesting tsunami waves >1 m high. Debris strandlines closer to TRV recorded runup heights as much as 8 m. We test the hypothesis that the strain signal is related to tsunami waves generated by successive pyroclastic flows induced during the dome collapse. Tsunami simulation models have been generated using GEOWAVE, which uses simple physics to recreate waves generated by idealized pyroclastic flows entering the sea at TRV. Each simulation run contains surface wave amplitude gauges located in key positions to the three borehole sites. These simulated wave amplitudes and periods are compared quantitatively with the data recorded by the dilatometers and with field observations of wave runup, to elucidate the dynamics of pyroclastic flow tsunami genesis and its propagation in shallow ocean water. </li> <li> <a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70030808','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70030808">Case study: Mapping tsunami hazards associated with debris flow into a reservoir</a> <a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a> Walder, J.S.; Watts, P.; Waythomas, C.F. 2006-01-01 Debris-flow generated impulse waves (tsunamis) pose hazards in lakes, especially those used for hydropower or recreation. We describe a method for assessing tsunami-related hazards for the case in which inundation by coherent water waves, rather than chaotic splashing, is of primary concern. The method involves an experimentally based initial condition (tsunami source) and a Boussinesq model for tsunami propagation and inundation. Model results are used to create hazard maps that offer guidance for emergency planners and responders. An example application explores tsunami hazards associated with potential debris flows entering Baker Lake, a reservoir on the flanks of the Mount Baker volcano in the northwestern United States. ?? 2006 ASCE. </li> <li> <a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70073331','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70073331">Local tsunamis and earthquake source parameters</a> <a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a> Geist, Eric L.; Dmowska, Renata; Saltzman, Barry 1999-01-01 This chapter establishes the relationship among earthquake source parameters and the generation, propagation, and run-up of local tsunamis. In general terms, displacement of the seafloor during the earthquake rupture is modeled using the elastic dislocation theory for which the displacement field is dependent on the slip distribution, fault geometry, and the elastic response and properties of the medium. Specifically, nonlinear long-wave theory governs the propagation and run-up of tsunamis. A parametric study is devised to examine the relative importance of individual earthquake source parameters on local tsunamis, because the physics that describes tsunamis from generation through run-up is complex. Analysis of the source parameters of various tsunamigenic earthquakes have indicated that the details of the earthquake source, namely, nonuniform distribution of slip along the fault plane, have a significant effect on the local tsunami run-up. Numerical methods have been developed to address the realistic bathymetric and shoreline conditions. The accuracy of determining the run-up on shore is directly dependent on the source parameters of the earthquake, which provide the initial conditions used for the hydrodynamic models. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013EGUGA..15.3903K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013EGUGA..15.3903K">Integrated Tsunami Database: simulation and identification of seismic tsunami sources, 3D visualization and post-disaster assessment on the shore</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Krivorot'ko, Olga; Kabanikhin, Sergey; Marinin, Igor; Karas, Adel; Khidasheli, David 2013-04-01 One of the most important problems of tsunami investigation is the problem of seismic tsunami source reconstruction. Non-profit organization WAPMERR (http://wapmerr.org) has provided a historical database of alleged tsunami sources around the world that obtained with the help of information about seaquakes. WAPMERR also has a database of observations of the tsunami waves in coastal areas. The main idea of presentation consists of determining of the tsunami source parameters using seismic data and observations of the tsunami waves on the shore, and the expansion and refinement of the database of presupposed tsunami sources for operative and accurate prediction of hazards and assessment of risks and consequences. Also we present 3D visualization of real-time tsunami wave propagation and loss assessment, characterizing the nature of the building stock in cities at risk, and monitoring by satellite images using modern GIS technology ITRIS (Integrated Tsunami Research and Information System) developed by WAPMERR and Informap Ltd. The special scientific plug-in components are embedded in a specially developed GIS-type graphic shell for easy data retrieval, visualization and processing. The most suitable physical models related to simulation of tsunamis are based on shallow water equations. We consider the initial-boundary value problem in Î© := {(x,y) ?R2 : x ?(0,Lx ), y ?(0,Ly ), Lx,Ly > 0} for the well-known linear shallow water equations in the Cartesian coordinate system in terms of the liquid flow components in dimensional form Here ?(x,y,t) defines the free water surface vertical displacement, i.e. amplitude of a tsunami wave, q(x,y) is the initial amplitude of a tsunami wave. The lateral boundary is assumed to be a non-reflecting boundary of the domain, that is, it allows the free passage of the propagating waves. Assume that the free surface oscillation data at points (xm, ym) are given as a measured output data from tsunami records: fm(t) := ? (xm, ym,t), (xm </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AGUFMNH23C1894W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AGUFMNH23C1894W">Tsunami Modeling of Hikurangi Trench M9 Events: Case Study for Napier, New Zealand</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Williams, C. R.; Nyst, M.; Farahani, R.; Bryngelson, J.; Lee, R.; Molas, G. 2015-12-01 RMS has developed a tsunami model for New Zealand for the insurance industry to price and to manage their tsunami risks. A key tsunamigenic source for New Zealand is the Hikurangi Trench that lies offshore on the eastside of the North Island. The trench is the result of the subduction of the Pacific Plate beneath the North Island at a rate of 40-45 mm/yr. Though there have been no M9 historical events on the Hikurangi Trench, events in this magnitude range are considered in the latest version of the National Seismic Hazard Maps for New Zealand (Stirling et al., 2012). The RMS modeling approaches the tsunami lifecycle in three stages: event generation, ocean wave propagation, and coastal inundation. The tsunami event generation is modeled based on seafloor deformation resulting from an event rupture model. The ocean wave propagation and coastal inundation are modeled using a RMS-developed numerical solver, implemented on graphic processing units using a finite-volume approach to approximate two-dimensional, shallow-water wave equations over the ocean and complex topography. As the tsunami waves enter shallow water and approach the coast, the RMS model calculates the propagation of the waves along the wet-dry interface considering variable land friction. The initiation and characteristics of the tsunami are based on the event rupture model. As there have been no historical M9 events on the Hikurangi Trench, this rupture characterization posed unique challenges. This study examined the impacts of a suite of event rupture models to understand the key drivers in the variations in the tsunami inundation footprints. The goal was to develop a suite of tsunamigenic event characterizations that represent a range of potential tsunami outcomes for M9 events on the Hikurangi Trench. The focus of this case study is the Napier region as it represents an important exposure concentration in the region and has experience tsunami inundations in the past including during the 1931 Ms7 </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017EGUGA..1914824L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017EGUGA..1914824L">Joint numerical study of the 2011 Tohoku-Oki tsunami: comparative propagation simulations and high resolution coastal models</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Loevenbruck, Anne; Arpaia, Luca; Ata, Riadh; Gailler, Audrey; Hayashi, Yutaka; Hébert, Hélène; Heinrich, Philippe; Le Gal, Marine; Lemoine, Anne; Le Roy, Sylvestre; Marcer, Richard; Pedreros, Rodrigo; Pons, Kevin; Ricchiuto, Mario; Violeau, Damien 2017-04-01 This study is part of the joint actions carried out within TANDEM (Tsunamis in northern AtlaNtic: Definition of Effects by Modeling). This French project, mainly dedicated to the appraisal of coastal effects due to tsunami waves on the French coastlines, was initiated after the catastrophic 2011 Tohoku-Oki tsunami. This event, which tragically struck Japan, drew the attention to the importance of tsunami risk assessment, in particular when nuclear facilities are involved. As a contribution to this challenging task, the TANDEM partners intend to provide guidance for the French Atlantic area based on numerical simulation. One of the identified objectives consists in designing, adapting and validating simulation codes for tsunami hazard assessment. Besides an integral benchmarking workpackage, the outstanding database of the 2011 event offers the TANDEM partners the opportunity to test their numerical tools with a real case. As a prerequisite, among the numerous published seismic source models arisen from the inversion of the various available records, a couple of coseismic slip distributions have been selected to provide common initial input parameters for the tsunami computations. After possible adaptations or specific developments, the different codes are employed to simulate the Tohoku-Oki tsunami from its source to the northeast Japanese coastline. The results are tested against the numerous tsunami measurements and, when relevant, comparisons of the different codes are carried out. First, the results related to the oceanic propagation phase are compared with the offshore records. Then, the modeled coastal impacts are tested against the onshore data. Flooding at a regional scale is considered, but high resolution simulations are also performed with some of the codes. They allow examining in detail the runup amplitudes and timing, as well as the complexity of the tsunami interaction with the coastal structures. The work is supported by the Tandem project in the </li> <li> <a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19860032177&hterms=tsunami&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3Dtsunami','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19860032177&hterms=tsunami&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3Dtsunami">The origin of the 1883 Krakatau tsunamis</a> <a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a> Francis, P. W. 1985-01-01 Three hypotheses proposed to explain possible causes of the Aug. 27, 1883 Krakatau tsunamis were analyzed: (1) large-scale collapse of the northern part of Krakatau island (Verbeek, 1884), (2) submarine explosion (Yokoyama, 1981), and (3) emplacement of pyroclastic flows (Latter, 1981). A study of timings of the air and sea waves between Krakatau and Batavia, showing that no precise sea wave travel times can be obtained, and a study of the tide and pressure gage records made on August 27, indicating that the air and sea waves were propagated from the focus of eruption on Krakatau island, suggest that neither hypothesis 2 or 3 are sufficiently substantiated. In addition, the event that caused the major air and sea wave was preceded (by 40 min) by a similar, smaller event which generated the second largest tsunami and an air wave. It is concluded that the most likely mechanism for the eruption is a Mt. St. Helens scenario, close to the hypothesis of Verbeek, in which collapse of part of the original volcanic edifice propagated a major explosion. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016EGUGA..18.1104S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016EGUGA..18.1104S">Meteotsunamis, destructive tsunami-like waves: from observations and simulations towards a warning system (MESSI)</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Sepic, Jadranka; Vilibic, Ivica 2016-04-01 Atmospherically-generated tsunami-like waves, also known as meteotsunamis, pose a severe threat for exposed coastlines. Although not as destructive as ordinary tsunamis, several meters high meteotsunami waves can bring destruction, cause loss of human lives and raise panic. For that reason, MESSI, an integrative meteotsunami research & warning project, has been developed and will be presented herein. The project has a threefold base: (1) research of atmosphere-ocean interaction with focus on (i) source processes in the atmosphere, (ii) energy transfer to the ocean and (iii) along-propagation growth of meteotsunami waves; (2) estimation of meteotsunami occurrence rates in past, present and future climate, and mapping of meteotsunami hazard; (3) construction of a meteotsunami warning system prototype, with the latter being the main objective of the project. Due to a great frequency of meteotsunamis and its complex bathymetry which varies from the shallow shelf in the north towards deep pits in the south, with a number of funnel-shaped bays and harbours substantially amplifying incoming tsunami-like waves, the Adriatic, northernmost of the Mediterranean seas, has been chosen as an ideal area for realization of the MESSI project and implementation of the warning system. This warning system will however be designed to allow for a wider applicability and easy-to-accomplish transfer to other endangered locations. The architecture of the warning system will integrate several components: (1) real-time measurements of key oceanographic and atmospheric parameters, (2) coupled atmospheric-ocean models run in real time (warning) mode, and (3) semi-automatic procedures and protocols for warning of civil protection, local authorities and public. The effectiveness of the warning system will be tested over the historic events. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018AdWR..115..273B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018AdWR..115..273B">A well-balanced meshless tsunami propagation and inundation model</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Brecht, Rüdiger; Bihlo, Alexander; MacLachlan, Scott; Behrens, Jörn 2018-05-01 We present a novel meshless tsunami propagation and inundation model. We discretize the nonlinear shallow-water equations using a well-balanced scheme relying on radial basis function based finite differences. For the inundation model, radial basis functions are used to extrapolate the dry region from nearby wet points. Numerical results against standard one- and two-dimensional benchmarks are presented. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013AGUFMNH41B1711W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013AGUFMNH41B1711W">Developing a global tsunami propagation database and its application for coastal hazard assessments in China</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Wang, N.; Tang, L.; Titov, V.; Newman, J. C.; Dong, S.; Wei, Y. 2013-12-01 The tragedies of the 2004 Indian Ocean and 2011 Japan tsunamis have increased awareness of tsunami hazards for many nations, including China. The low land level and high population density of China's coastal areas place it at high risk for tsunami hazards. Recent research (Komatsubara and Fujiwara, 2007) highlighted concerns of a magnitude 9.0 earthquake on the Nankai trench, which may affect China's coasts not only in South China Sea, but also in the East Sea and Yellow Sea. Here we present our work in progress towards developing a global tsunami propagation database that can be used for hazard assessments by many countries. The propagation scenarios are computed by using NOAA's MOST numerical model. Each scenario represents a typical Mw 7.5 earthquake with predefined earthquake parameters (Gica et al., 2008). The model grid was interpolated from ETOPO1 at 4 arc-min resolution, covering -80° to72°N and 0 to 360°E. We use this database for preliminary tsunami hazard assessment along China's coastlines. </li> <li> <a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70160542','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70160542">Non-linear resonant coupling of tsunami edge waves using stochastic earthquake source models</a> <a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a> Geist, Eric L. 2016-01-01 Non-linear resonant coupling of edge waves can occur with tsunamis generated by large-magnitude subduction zone earthquakes. Earthquake rupture zones that straddle beneath the coastline of continental margins are particularly efficient at generating tsunami edge waves. Using a stochastic model for earthquake slip, it is shown that a wide range of edge-wave modes and wavenumbers can be excited, depending on the variability of slip. If two modes are present that satisfy resonance conditions, then a third mode can gradually increase in amplitude over time, even if the earthquake did not originally excite that edge-wave mode. These three edge waves form a resonant triad that can cause unexpected variations in tsunami amplitude long after the first arrival. An M ∼ 9, 1100 km-long continental subduction zone earthquake is considered as a test case. For the least-variable slip examined involving a Gaussian random variable, the dominant resonant triad includes a high-amplitude fundamental mode wave with wavenumber associated with the along-strike dimension of rupture. The two other waves that make up this triad include subharmonic waves, one of fundamental mode and the other of mode 2 or 3. For the most variable slip examined involving a Cauchy-distributed random variable, the dominant triads involve higher wavenumbers and modes because subevents, rather than the overall rupture dimension, control the excitation of edge waves. Calculation of the resonant period for energy transfer determines which cases resonant coupling may be instrumentally observed. For low-mode triads, the maximum transfer of energy occurs approximately 20–30 wave periods after the first arrival and thus may be observed prior to the tsunami coda being completely attenuated. Therefore, under certain circumstances the necessary ingredients for resonant coupling of tsunami edge waves exist, indicating that resonant triads may be observable and implicated in late, large-amplitude tsunami arrivals. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018PApGe.175.1387D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018PApGe.175.1387D">Tsunami Wave Run-up on a Vertical Wall in Tidal Environment</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Didenkulova, Ira; Pelinovsky, Efim 2018-04-01 We solve analytically a nonlinear problem of shallow water theory for the tsunami wave run-up on a vertical wall in tidal environment. Shown that the tide can be considered static in the process of tsunami wave run-up. In this approximation, it is possible to obtain the exact solution for the run-up height as a function of the incident wave height. This allows us to investigate the tide influence on the run-up characteristics. </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_3");'>3</a></li> <li><a href="#" onclick='return showDiv("page_4");'>4</a></li> <li class="active">5</li> <li><a href="#" onclick='return showDiv("page_6");'>6</a></li> <li><a href="#" onclick='return showDiv("page_7");'>7</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> </div> <div id="page_6" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_4");'>4</a></li> <li><a href="#" onclick='return showDiv("page_5");'>5</a></li> <li class="active">6</li> <li><a href="#" onclick='return showDiv("page_7");'>7</a></li> <li><a href="#" onclick='return showDiv("page_8");'>8</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="101"> <li> <a target="_blank" onclick="trackOutboundLink('https://eric.ed.gov/?q=tsunami&pg=7&id=EJ758490','ERIC'); return false;" href="https://eric.ed.gov/?q=tsunami&pg=7&id=EJ758490">Waves and Tsunami Project</a> <a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a> Frashure, K. M.; Chen, R. F.; Stephen, R. A.; Bolmer, T.; Lavin, M.; Strohschneider, D.; Maichle, R.; Micozzi, N.; Cramer, C. 2007-01-01 Demonstrating wave processes quantitatively in the classroom using standard classroom tools (such as Slinkys and wave tanks) can be difficult. For example, waves often travel too fast for students to actually measure amplitude or wavelength. Also, when teaching propagating waves, reflections from the ends set up standing waves, which can confuse… </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011PApGe.168.2043I','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011PApGe.168.2043I">Anatomy of Historical Tsunamis: Lessons Learned for Tsunami Warning</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Igarashi, Y.; Kong, L.; Yamamoto, M.; McCreery, C. S. 2011-11-01 Tsunamis are high-impact disasters that can cause death and destruction locally within a few minutes of their occurrence and across oceans hours, even up to a day, afterward. Efforts to establish tsunami warning systems to protect life and property began in the Pacific after the 1946 Aleutian Islands tsunami caused casualties in Hawaii. Seismic and sea level data were used by a central control center to evaluate tsunamigenic potential and then issue alerts and warnings. The ensuing events of 1952, 1957, and 1960 tested the new system, which continued to expand and evolve from a United States system to an international system in 1965. The Tsunami Warning System in the Pacific (ITSU) steadily improved through the decades as more stations became available in real and near-real time through better communications technology and greater bandwidth. New analysis techniques, coupled with more data of higher quality, resulted in better detection, greater solution accuracy, and more reliable warnings, but limitations still exist in constraining the source and in accurately predicting propagation of the wave from source to shore. Tsunami event data collected over the last two decades through international tsunami science surveys have led to more realistic models for source generation and inundation, and within the warning centers, real-time tsunami wave forecasting will become a reality in the near future. The tsunami warning system is an international cooperative effort amongst countries supported by global and national monitoring networks and dedicated tsunami warning centers; the research community has contributed to the system by advancing and improving its analysis tools. Lessons learned from the earliest tsunamis provided the backbone for the present system, but despite 45 years of experience, the 2004 Indian Ocean tsunami reminded us that tsunamis strike and kill everywhere, not just in the Pacific. Today, a global intergovernmental tsunami warning system is coordinated </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012EGUGA..14..105D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012EGUGA..14..105D">Nonlinear wave runup in long bays and firths: Samoa 2009 and Tohoku 2011 tsunamis</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Didenkulova, I.; Pelinovsky, E. 2012-04-01 Last catastrophic tsunami events in Samoa on 29 September 2009 and in Japan on 11 March 2011 demonstrated that tsunami may experience abnormal amplification in long bays and firths and result in an unexpectedly high wave runup. The capital city Pago Pago, which is located at the toe of a narrow 4-km-long bay and represents the most characteristic example of a long and narrow bay, was considerably damaged during Samoa 2009 tsunami (destroyed infrastructures, boats and shipping containers carried inland into commercial areas, etc.) The runup height there reached 8 m over an inundation of 538 m at its toe, while the tsunami wave height measured by the tide-gauge at the entrance of the bay was at most 3 m. The same situation was observed during catastrophic Tohoku tsunami in Japan, which coast contains numerous long bays and firths, which experienced the highest wave runup and the strongest amplification. Such examples are villages: Ofunato, Ryori Bay, where the wave runup reached 30 m high, and Onagawa, where the wave amplified up to 17 m. Here we study the nonlinear dynamics of tsunami waves in an inclined U-shaped bay. Nonlinear shallow water equations can in this case be written in 1D form and solved analytically with the use of the hodograph transformation. This approach generalizes the well-known Carrier-Greenspan transformation for long wave runup on a plane beach. In the case of an inclined U-shaped bay it leads to the associated generalized wave equation for symmetrical wave in fractal space. In the special case of the channel of parabolic cross-section it is a spherical symmetrical linear wave equation. As a result, the solution of the Cauchy problem can be expressed in terms of elementary functions and has a simple form (with respect to analysis) for any kind of initial conditions. Wave regimes associated with various localized initial conditions, corresponding to problems of evolution and runup of tsunami, are considered and analyzed. Special attention is </li> <li> <a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/20995674-evaluation-numerical-simulation-tsunami-coastal-nuclear-power-plants-india','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/20995674-evaluation-numerical-simulation-tsunami-coastal-nuclear-power-plants-india">Evaluation and Numerical Simulation of Tsunami for Coastal Nuclear Power Plants of India</a> <a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a> Sharma, Pavan K.; Singh, R.K.; Ghosh, A.K. 2006-07-01 Recent tsunami generated on December 26, 2004 due to Sumatra earthquake of magnitude 9.3 resulted in inundation at the various coastal sites of India. The site selection and design of Indian nuclear power plants demand the evaluation of run up and the structural barriers for the coastal plants: Besides it is also desirable to evaluate the early warning system for tsunami-genic earthquakes. The tsunamis originate from submarine faults, underwater volcanic activities, sub-aerial landslides impinging on the sea and submarine landslides. In case of a submarine earthquake-induced tsunami the wave is generated in the fluid domain due to displacement of themore » seabed. There are three phases of tsunami: generation, propagation, and run-up. Reactor Safety Division (RSD) of Bhabha Atomic Research Centre (BARC), Trombay has initiated computational simulation for all the three phases of tsunami source generation, its propagation and finally run up evaluation for the protection of public life, property and various industrial infrastructures located on the coastal regions of India. These studies could be effectively utilized for design and implementation of early warning system for coastal region of the country apart from catering to the needs of Indian nuclear installations. This paper presents some results of tsunami waves based on different analytical/numerical approaches with shallow water wave theory. (authors)« less </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AGUFMNH41A1748M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUFMNH41A1748M">Advancing our understanding of the onshore propagation of tsunami bores over rough surfaces through numerical modeling</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Marras, S.; Suckale, J.; Eguzkitza, B.; Houzeaux, G.; Vázquez, M.; Lesage, A. C. 2016-12-01 The propagation of tsunamis in the open ocean has been studied in detail with many excellent numerical approaches available to researchers. Our understanding of the processes that govern the onshore propagation of tsunamis is less advanced. Yet, the reach of tsunamis on land is an important predictor of the damage associated with a given event, highlighting the need to investigate the factors that govern tsunami propagation onshore. In this study, we specifically focus on understanding the effect of bottom roughness at a variety of scales. The term roughness is to be understood broadly, as it represents scales ranging from small features like rocks, to vegetation, up to the size of larger structures and topography. In this poster, we link applied mathematics, computational fluid dynamics, and tsunami physics to analyze the small scales features of coastal hydrodynamics and the effect of roughness on the motion of tsunamis as they run up a sloping beach and propagate inland. We solve the three-dimensional Navier-Stokes equations of incompressible flows with free surface, which is tracked by a level set function in combination with an accurate re-distancing scheme. We discretize the equations via linear finite elements for space approximation and fully implicit time integration. Stabilization is achieved via the variational multiscale method whereas the subgrid scales for our large eddy simulations are modeled using a dynamically adaptive Smagorinsky eddy viscosity. As the geometrical characteristics of roughness in this study vary greatly across different scales, we implement a scale-dependent representation of the roughness elements. We model the smallest sub-grid scale roughness features by the use of a properly defined law of the wall. Furthermore, we utilize a Manning formula to compute the shear stress at the boundary. As the geometrical scales become larger, we resolve the geometry explicitly and compute the effective volume drag introduced by large scale </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2008spa..book.1535W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2008spa..book.1535W">Seismic Wave Propagation</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Wu, Xianyun; Wu, Ru-Shan A seismic wave is a mechanical disturbance or energy packet that can propagate from point to point in the Earth. Seismic waves can be generated by a sudden release of energy such as an earthquake, volcanic eruption, or chemical explosion. There are several types of seismic waves, often classified as body waves, which propagate through the volume of the Earth, and surface waves, which travel along the surface of the Earth. Compressional and shear waves are the two main types of body wave and Rayleigh and Love waves are the most common forms of surface wave. </li> <li> <a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/22230771-tsunami-acoustic-gravity-waves-water-constant-depth','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/22230771-tsunami-acoustic-gravity-waves-water-constant-depth">Tsunami and acoustic-gravity waves in water of constant depth</a> <a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a> Hendin, Gali; Stiassnie, Michael 2013-08-15 A study of wave radiation by a rather general bottom displacement, in a compressible ocean of otherwise constant depth, is carried out within the framework of a three-dimensional linear theory. Simple analytic expressions for the flow field, at large distance from the disturbance, are derived. Realistic numerical examples indicate that the Acoustic-Gravity waves, which significantly precede the Tsunami, are expected to leave a measurable signature on bottom-pressure records that should be considered for early detection of Tsunami. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012AGUFMNH32A..04K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012AGUFMNH32A..04K">Tsunami Forecasting in the Atlantic Basin</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Knight, W. R.; Whitmore, P.; Sterling, K.; Hale, D. A.; Bahng, B. 2012-12-01 The mission of the West Coast and Alaska Tsunami Warning Center (WCATWC) is to provide advance tsunami warning and guidance to coastal communities within its Area-of-Responsibility (AOR). Predictive tsunami models, based on the shallow water wave equations, are an important part of the Center's guidance support. An Atlantic-based counterpart to the long-standing forecasting ability in the Pacific known as the Alaska Tsunami Forecast Model (ATFM) is now developed. The Atlantic forecasting method is based on ATFM version 2 which contains advanced capabilities over the original model; including better handling of the dynamic interactions between grids, inundation over dry land, new forecast model products, an optional non-hydrostatic approach, and the ability to pre-compute larger and more finely gridded regions using parallel computational techniques. The wide and nearly continuous Atlantic shelf region presents a challenge for forecast models. Our solution to this problem has been to develop a single unbroken high resolution sub-mesh (currently 30 arc-seconds), trimmed to the shelf break. This allows for edge wave propagation and for kilometer scale bathymetric feature resolution. Terminating the fine mesh at the 2000m isobath keeps the number of grid points manageable while allowing for a coarse (4 minute) mesh to adequately resolve deep water tsunami dynamics. Higher resolution sub-meshes are then included around coastal forecast points of interest. The WCATWC Atlantic AOR includes eastern U.S. and Canada, the U.S. Gulf of Mexico, Puerto Rico, and the Virgin Islands. Puerto Rico and the Virgin Islands are in very close proximity to well-known tsunami sources. Because travel times are under an hour and response must be immediate, our focus is on pre-computing many tsunami source "scenarios" and compiling those results into a database accessible and calibrated with observations during an event. Seismic source evaluation determines the order of model pre </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018PApGe.175.1545S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018PApGe.175.1545S">Odessa Tsunami of 27 June 2014: Observations and Numerical Modelling</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Šepić, Jadranka; Rabinovich, Alexander B.; Sytov, Victor N. 2018-04-01 On 27 June, a 1-2-m high wave struck the beaches of Odessa, the third largest Ukrainian city, and the neighbouring port-town Illichevsk (northwestern Black Sea). Throughout the day, prominent seiche oscillations were observed in several other ports of the Black Sea. Tsunamigenic synoptic conditions were found over the Black Sea, stretching from Romania in the west to the Crimean Peninsula in the east. Intense air pressure disturbances and convective thunderstorm clouds were associated with these conditions; right at the time of the event, a 1.5-hPa air pressure jump was recorded at Odessa and a few hours earlier in Romania. We have utilized a barotropic ocean numerical model to test two hypotheses: (1) a tsunami-like wave was generated by an air pressure disturbance propagating directly over Odessa ("Experiment 1"); (2) a tsunami-like wave was generated by an air pressure disturbance propagating offshore, approximately 200 km to the south of Odessa, and along the shelf break ("Experiment 2"). Both experiments decisively confirm the meteorological origin of the tsunami-like waves on the coast of Odessa and imply that intensified long ocean waves in this region were generated via the Proudman resonance mechanism while propagating over the northwestern Black Sea shelf. The "Odessa tsunami" of 27 June 2014 was identified as a "beach meteotsunami", similar to events regularly observed on the beaches of Florida, USA, but different from the "harbour meteotsunamis", which occurred 1-3 days earlier in Ciutadella (Baleares, Spain), Mazara del Vallo (Sicily, Italy) and Vela Luka (Croatia) in the Mediterranean Sea, despite that they were associated with the same atmospheric system moving over the Mediterranean/Black Sea region on 23-27 June 2014. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AGUFMNH34A..03S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUFMNH34A..03S">SEQUENCING of TSUNAMI WAVES: Why the first wave is not always the largest?</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Synolakis, C.; Okal, E. 2016-12-01 We discuss what contributes to the `sequencing' of tsunami waves in the far field, that is, to the distribution of the maximum sea surface amplitude inside the dominant wave packet constituting the primary arrival at a distant harbour. Based on simple models of sources for which analytical solutions are available, we show that, as range is increased, the wave pattern evolves from a regime of maximum amplitude in the first oscillation to one of delayed maximum, where the largest amplitude takes place during a subsequent oscillation. In the case of the simple, instantaneous uplift of a circular disk at the surface of an ocean of constant depth, the critical distance for transition between those patterns scales as r 30 /h2 where r0 is the radius of the disk and h the depth of the ocean. This behaviour is explained from simple arguments based on a model where sequencing results from frequency dispersion in the primary wave packet, as the width of its spectrum around its dominant period T0 becomes dispersed in time in an amount comparable to T0 , the latter being controlled by a combination of source size and ocean depth. The general concepts in this model are confirmed in the case of more realistic sources for tsunami excitation by a finite-time deformation of the ocean floor, as well as in real-life simulations of tsunamis excited by large subduction events, for which we find that the influence of fault width on the distribution of sequencing is more important than that of fault length. Finally, simulation of the major events of Chile (2010) and Japan (2011) at large arrays of virtual gauges in the Pacific Basin correctly predicts the majority of the sequencing patterns observed on DART buoys during these events. By providing insight into the evolution with time of wave amplitudes inside primary wave packets for far field tsunamis generated by large earthquakes, our results stress the importance, for civil defense authorities, of issuing warning and evacuation orders </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010EGUGA..1210998Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010EGUGA..1210998Z">Modeling of influence from remote tsunami at the coast of Sakhalin and Kuriles islands.</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Zaytsev, Andrey; Pelinovsky, Efim; Yalciner, Ahmet; Chernov, Anton; Kostenko, Irina 2010-05-01 The Far East coast of Russia (Kuriles islands, Sakhalin, Kamchatka) is the area where the dangerous natural phenomena as tsunami is located. A lot of works are established for decreasing of tsunami's influence. Tsunami mapping and mitigation strategy are given for some regions. The centers of Tsunami Warning System are opened, enough plenty of records of a tsunami are collected. The properties of local tsunami are studied well. At the same time, the catastrophic event of the Indonesian tsunami, which had happened in December, 2004, when the sufficient waves have reached the coasts of Africa and South America, it is necessary to note, that the coats, which was far from the epicenter of earthquakes can be effected by catastrophic influence. Moreover, it is practically unique case, when using Tsunami Warning System can reduce the number of human victims to zero. Development of the computer technologies, numerical methods for the solution of systems of the nonlinear differential equations makes computer modeling real and hypothetical tsunamis is the basic method of studying features of distribution of waves in water areas and their influence at coast. Numerical modeling of distribution of historical tsunami from the seismic sources in the Pacific Ocean was observed. The events with an epicenter, remote from Far East coast of Russia were considered. The estimation of the remote tsunami waves propagation was developed. Impact force of tsunamis was estimated. The features of passage of tsunami through Kuril Straits were considered. The spectral analysis of records in settlements of Sakhalin and Kuriles is lead. NAMI-DANCE program was used for tsunami propagation numerical modeling. It is used finite element numerical schemes for Shallow Water Equations and Nonlinear-Dispersive Equations, with use Nested Grid. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AGUFMNH43B1849Y','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUFMNH43B1849Y">Hydraulic experiment on tsunami sand deposits relating with grain size distribution and magnitude of incident waves</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Yamamoto, A.; Takahashi, T.; Harada, K.; Nojima, K. 2016-12-01 A huge earthquake occurred off the Tohoku district in Japan on March 11th, 2011. A massive tsunami generated by the earthquake attacked coastal areas and caused serious damage. The tsunami disaster requires to reconsider tsunami measures in the Nankai Trough. Many of the measures are based on histories of large earthquakes and tsunamis. Because they are low frequency disasters and their historical documents are limited, tsunami sand deposits have been expected to analyze paleotsunamis. Tsunami sand deposits, however, are only used to confirm the fact of tsunamis and to determine the relative magnitudes. The thickness of sand layer and the grain size may be clues to estimate the tsunami force. Further, it could reveal the tsunami source. These results are also useful to improve the present tsunami measures. The objective of this study is to investigate the formation mechanism of tsunami sand deposits by hydraulic experiment. A two-dimensional water channel consisted of a wave maker, a flat section and a slope section. A movable bed section with various grain sizes and distribution of sand was set at the end of flat section. Bore waves of several heights transported the sand to the slope section by run-up. Water surface elevation and velocity were measured at several points. Tsunami sand deposit distribution was also measured along the slope section. The experimental result showed that the amount of tsunami sand deposit was relating with the grain size distribution and the magnitude of incident waves. Further, the number of incident waves affected the profile of tsunami sand deposits. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AGUOSPO12A..03M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUOSPO12A..03M">Modeling the propagation, transformation and the impact of tsunami on urban areas using the coupling STOC-ML/IC/CADMAS in nested grids - Application to specific sites of Chile to improve the tsunami induced loads prediction.</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Mokrani, C.; Catalan, P. A.; Cienfuegos, R.; Arikawa, T. 2016-02-01 A large part of coasts around the world are affected by tsunami impacts, which supposes a challenge when designing coastal protection structures. Numerical models provide predictions of tsunami-induced loads and there time evolution, which can be used to improve sizing rules of coastal structures. However, the numerical assessment of impact loads is an hard stake. Indeed, recent experimental studies have shown that pressure dynamics generated during tsunami impacts are highly sensitive to the incident local shape of the tsunami. Therefore, high numerical resolutions and very accurate models are required to model all stages during which the tsunami shape is modified before the impact. Given the large distances involved in tsunami events, this can be disregarded in favor of computing time. The Port and Airport Research Institute (PARI) has recently developed a three-way coupled model which allows to accurately model the incident tsunami shape while maintaining reasonable computational time. This coupling approach uses three models used in nested grids (cf. Figure 1). The first one (STOC-ML) solves Nonlinear Shallow Water Equations with hydrostatic pressure. It is used to model the tsunami propagation off the coast. The second one (STOC-IC) is a 3D non-hydrostatic model, on which the free-surface position is estimated through the integrated continuity equation. It has shown to accurately describe dispersive and weakly linear effects occurring at the coast vicinity. The third model (CADMAS-SURF) solves fully three-dimensional Navier-Stokes equations and use a VOF method. Highly nonlinear, dispersive effects and wave breaking processes can be included at the wave scale and therefore, a very accurate description of the incident tsunami is provided. Each model have been separately validated from analytical and/or experimental data. The present objective is to highlight recent advances in Coastal Ocean modeling for tsunami modeling and loads prediction by applying this </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010EGUGA..12.5812H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010EGUGA..12.5812H">Large Historical Earthquakes and Tsunami Hazards in the Western Mediterranean: Source Characteristics and Modelling</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Harbi, Assia; Meghraoui, Mustapha; Belabbes, Samir; Maouche, Said 2010-05-01 The western Mediterranean region was the site of numerous large earthquakes in the past. Most of these earthquakes are located at the East-West trending Africa-Eurasia plate boundary and along the coastline of North Africa. The most recent recorded tsunamigenic earthquake occurred in 2003 at Zemmouri-Boumerdes (Mw 6.8) and generated ~ 2-m-high tsunami wave. The destructive wave affected the Balearic Islands and Almeria in southern Spain and Carloforte in southern Sardinia (Italy). The earthquake provided a unique opportunity to gather instrumental records of seismic waves and tide gauges in the western Mediterranean. A database that includes a historical catalogue of main events, seismic sources and related fault parameters was prepared in order to assess the tsunami hazard of this region. In addition to the analysis of the 2003 records, we study the 1790 Oran and 1856 Jijel historical tsunamigenic earthquakes (Io = IX and X, respectively) that provide detailed observations on the heights and extension of past tsunamis and damage in coastal zones. We performed the modelling of wave propagation using NAMI-DANCE code and tested different fault sources from synthetic tide gauges. We observe that the characteristics of seismic sources control the size and directivity of tsunami wave propagation on both northern and southern coasts of the western Mediterranean. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2007AGUFM.S53A1029L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2007AGUFM.S53A1029L">Tsunami Detection Systems for International Requirements</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Lawson, R. A. 2007-12-01 Results are presented regarding the first commercially available, fully operational, tsunami detection system to have passed stringent U.S. government testing requirements and to have successfully demonstrated its ability to detect an actual tsunami at sea. Spurred by the devastation of the December 26, 2004, Indian Ocean tsunami that killed more than 230,000 people, the private sector actively supported the Intergovernmental Oceanographic Commission's (IOC"s) efforts to develop a tsunami warning system and mitigation plan for the Indian Ocean region. As each country in the region developed its requirements, SAIC recognized that many of these underdeveloped countries would need significant technical assistance to fully execute their plans. With the original focus on data fusion, consequence assessment tools, and warning center architecture, it was quickly realized that the cornerstone of any tsunami warning system would be reliable tsunami detection buoys that could meet very stringent operational standards. Our goal was to leverage extensive experience in underwater surveillance and oceanographic sensing to produce an enhanced and reliable deep water sensor that could meet emerging international requirements. Like the NOAA Deep-ocean Assessment and Recording of Tsunamis (DART TM ) buoy, the SAIC Tsunami Buoy (STB) system consists of three subsystems: a surfaccommunications buoy subsystem, a bottom pressure recorder subsystem, and a buoy mooring subsystem. With the operational success that DART has demonstrated, SAIC decided to build and test to the same high standards. The tsunami detection buoy system measures small changes in the depth of the deep ocean caused by tsunami waves as they propagate past the sensor. This is accomplished by using an extremely sensitive bottom pressure sensor/recorder to measure very small changes in pressure as the waves move past the buoy system. The bottom pressure recorder component includes a processor with algorithms that </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017EGUGA..1913813V','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017EGUGA..1913813V">Modeling the 16 September 2015 Chile tsunami source with the inversion of deep-ocean tsunami records by means of the r - solution method</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Voronina, Tatyana; Romanenko, Alexey; Loskutov, Artem 2017-04-01 The key point in the state-of-the-art in the tsunami forecasting is constructing a reliable tsunami source. In this study, we present an application of the original numerical inversion technique to modeling the tsunami sources of the 16 September 2015 Chile tsunami. The problem of recovering a tsunami source from remote measurements of the incoming wave in the deep-water tsunameters is considered as an inverse problem of mathematical physics in the class of ill-posed problems. This approach is based on the least squares and the truncated singular value decomposition techniques. The tsunami wave propagation is considered within the scope of the linear shallow-water theory. As in inverse seismic problem, the numerical solutions obtained by mathematical methods become unstable due to the presence of noise in real data. A method of r-solutions makes it possible to avoid instability in the solution to the ill-posed problem under study. This method seems to be attractive from the computational point of view since the main efforts are required only once for calculating the matrix whose columns consist of computed waveforms for each harmonic as a source (an unknown tsunami source is represented as a part of a spatial harmonics series in the source area). Furthermore, analyzing the singular spectra of the matrix obtained in the course of numerical calculations one can estimate the future inversion by a certain observational system that will allow offering a more effective disposition for the tsunameters with the help of precomputations. In other words, the results obtained allow finding a way to improve the inversion by selecting the most informative set of available recording stations. The case study of the 6 February 2013 Solomon Islands tsunami highlights a critical role of arranging deep-water tsunameters for obtaining the inversion results. Implementation of the proposed methodology to the 16 September 2015 Chile tsunami has successfully produced tsunami source model </li> <li> <a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28203640','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28203640">Tsunami mitigation by resonant triad interaction with acoustic-gravity waves.</a> <a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a> Kadri, Usama 2017-01-01 Tsunamis have been responsible for the loss of almost a half million lives, widespread long lasting destruction, profound environmental effects, and global financial crisis, within the last two decades. The main tsunami properties that determine the size of impact at the shoreline are its wavelength and amplitude in the ocean. Here, we show that it is in principle possible to reduce the amplitude of a tsunami, and redistribute its energy over a larger space, through forcing it to interact with resonating acoustic-gravity waves. In practice, generating the appropriate acoustic-gravity modes introduces serious challenges due to the high energy required for an effective interaction. However, if the findings are extended to realistic tsunami properties and geometries, we might be able to mitigate tsunamis and so save lives and properties. Moreover, such a mitigation technique would allow for the harnessing of the tsunami's energy. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2008AGUSM.H53B..01F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2008AGUSM.H53B..01F">Peru 2007 tsunami runup observations and modeling</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Fritz, H. M.; Kalligeris, N.; Borrero, J. C. 2008-05-01 On 15 August 2007 an earthquake with moment magnitude (Mw) of 8.0 centered off the coast of central Peru, generated a tsunami with locally focused runup heights of up to 10 m. A reconnaissance team was deployed in the immediate aftermath and investigated the tsunami effects at 51 sites. The largest runup heights were measured in a sparsely populated desert area south of the Paracas Peninsula resulting in only 3 tsunami fatalities. Numerical modeling of the earthquake source and tsunami suggest that a region of high slip near the coastline was primarily responsible for the extreme runup heights. The town of Pisco was spared by the presence of the Paracas Peninsula, which blocked tsunami waves from propagating northward from the high slip region. The coast of Peru has experienced numerous deadly and destructive tsunamis throughout history, which highlights the importance of ongoing tsunami awareness and education efforts in the region. The Peru tsunami is compared against recent mega-disasters such as the 2004 Indian Ocean tsunami and Hurricane Katrina. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017JGRA..122.7742B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017JGRA..122.7742B">Origin of the ahead of tsunami traveling ionospheric disturbances during Sumatra tsunami and offshore forecasting</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Bagiya, Mala S.; Kherani, E. A.; Sunil, P. S.; Sunil, A. S.; Sunda, S.; Ramesh, D. S. 2017-07-01 The presence of ionospheric disturbances associated with Sumatra 2004 tsunami that propagated ahead of tsunami itself has previously been identified. However, their origin remains unresolved till date. Focusing on their origin mechanism, we document these ionospheric disturbances referred as Ahead of tsunami Traveling Ionospheric Disturbances (ATIDs). Using total electron content (TEC) data from GPS Aided GEO Augmented Navigation GPS receivers located near the Indian east coast, we first confirm the ATIDs presence in TEC that appear 90 min ahead of the arrival of tsunami at the Indian east coast. We propose here a simulation study based on tsunami-atmospheric-ionospheric coupling that considers tsunamigenic acoustic gravity waves (AGWs) to excite these disturbances. We explain the ATIDs generation based on the dissipation of transverse mode of the primary AGWs. The simulation corroborates the excitation of ATIDs with characteristics similar to the observations. Therefore, we offer an alternative theoretical tool to monitor the offshore ATIDs where observations are either rare or not available and could be potentially important for the tsunami early warning. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018JGRC..123.2965T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018JGRC..123.2965T">Tsunami Waves and Tsunami-Induced Natural Oscillations Determined by HF Radar in Ise Bay, Japan</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Toguchi, Y.; Fujii, S.; Hinata, H. 2018-04-01 Tsunami waves and the subsequent natural oscillations generated by the 2011 Tohoku earthquake were observed by two high-frequency (HF) radars and four tidal gauge records in Ise Bay. The radial velocity components of both records increased abruptly at approximately 17:00 (JST) and continued for more than 24 h. This indicated that natural oscillations followed the tsunami in Ise Bay. The spectral analyses showed that the tsunami wave arrivals had periods of 16-19, 30-40, 60-90, and 120-140 min. The three longest periods were remarkably amplified. Time-frequency analysis also showed the energy increase and duration of these periods. We used an Empirical Orthogonal Function (EOF) to analyze the total velocity of the currents to find the underlying oscillation patterns in the three longest periods. To verify the physical properties of the EOF analysis results, we calculated the oscillation modes in Ise Bay using a numerical model proposed by Loomis. The results of EOF analysis showed that the oscillation modes of 120-140 and 60-90 min period bands were distributed widely, whereas the oscillation mode of the 30-40 min period band was distributed locally. The EOF spatial patterns of each period showed good agreement with the eigenmodes calculated by the method of Loomis (1975). Thus, the HF radars were capable of observing the tsunami arrival and the subsequent oscillations. </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_4");'>4</a></li> <li><a href="#" onclick='return showDiv("page_5");'>5</a></li> <li class="active">6</li> <li><a href="#" onclick='return showDiv("page_7");'>7</a></li> <li><a href="#" onclick='return showDiv("page_8");'>8</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> </div> <div id="page_7" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_5");'>5</a></li> <li><a href="#" onclick='return showDiv("page_6");'>6</a></li> <li class="active">7</li> <li><a href="#" onclick='return showDiv("page_8");'>8</a></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="121"> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AGUFM.S21A4417O','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AGUFM.S21A4417O">Tsunami hazard assessment in the Colombian Caribbean Coast with a deterministic approach</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Otero Diaz, L.; Correa, R.; Ortiz R, J. C.; Restrepo L, J. C. 2014-12-01 For the Caribbean Sea, we propose six potential tectonic sources of tsunami, defining for each source the worst credible earthquake from the analysis of historical seismicity, tectonics, pasts tsunami, and review of IRIS, PDE, NOAA, and CMT catalogs. The generation and propagation of tsunami waves in the selected sources were simulated with COMCOT 1.7, which is a numerical model that solves the linear and nonlinear long wave equations in finite differences in both Cartesian, and spherical coordinates. The results of the modeling are presented in maps of maximum displacement of the free surface for the Colombian Caribbean coast and the island areas, and they show that the event would produce greater impact is generated in the source of North Panama Deformed Belt (NPDB), where the first wave train reaches the central Colombian coast in 40 minutes, generating wave heights up to 3.7 m. In San Andrés and Providencia island, tsunami waves reach more than 4.5 m due effects of edge waves caused by interactions between waves and a barrier coral reef around of each island. The results obtained in this work are useful for planning systems and future regional and local warning systems and to identify priority areas to conduct detailed research to the tsunami threat. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010AGUFM.G33A0830U','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010AGUFM.G33A0830U">Modeling influence of tide stages on forecasts of the 2010 Chilean tsunami</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Uslu, B. U.; Chamberlin, C.; Walsh, D.; Eble, M. C. 2010-12-01 The impact of the 2010 Chilean tsunami is studied using the NOAA high-resolution tsunami forecast model augmented to include modeled tide heights in addition to deep-water tsunami propagation as boundary-condition input. The Chilean tsunami was observed at the Los Angeles tide station at mean low water, Hilo at low, Pago Pago at mid tide and Wake Island near high tide. Because the tsunami arrived at coastal communities at a representative variety of tide stages, 2010 Chile tsunami provides opportunity to study the tsunami impacts at different tide levels to different communities. The current forecast models are computed with a constant tidal stage, and this study evaluates techniques for adding an additional varying predicted tidal component in a forecasting context. Computed wave amplitudes, wave currents and flooding are compared at locations around the Pacific, and the difference in tsunami impact due to tidal stage is studied. This study focuses on how tsunami impacts vary with different tide levels, and helps us understand how the inclusion of tidal components can improve real-time forecast accuracy. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015JGRC..120.4945R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015JGRC..120.4945R">Source location impact on relative tsunami strength along the U.S. West Coast</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Rasmussen, L.; Bromirski, P. D.; Miller, A. J.; Arcas, D.; Flick, R. E.; Hendershott, M. C. 2015-07-01 Tsunami propagation simulations are used to identify which tsunami source locations would produce the highest amplitude waves on approach to key population centers along the U.S. West Coast. The reasons for preferential influence of certain remote excitation sites are explored by examining model time sequences of tsunami wave patterns emanating from the source. Distant bathymetric features in the West and Central Pacific can redirect tsunami energy into narrow paths with anomalously large wave height that have disproportionate impact on small areas of coastline. The source region generating the waves can be as little as 100 km along a subduction zone, resulting in distinct source-target pairs with sharply amplified wave energy at the target. Tsunami spectral ratios examined for transects near the source, after crossing the West Pacific, and on approach to the coast illustrate how prominent bathymetric features alter wave spectral distributions, and relate to both the timing and magnitude of waves approaching shore. To contextualize the potential impact of tsunamis from high-amplitude source-target pairs, the source characteristics of major historical earthquakes and tsunamis in 1960, 1964, and 2011 are used to generate comparable events originating at the highest-amplitude source locations for each coastal target. This creates a type of "worst-case scenario," a replicate of each region's historically largest earthquake positioned at the fault segment that would produce the most incoming tsunami energy at each target port. An amplification factor provides a measure of how the incoming wave height from the worst-case source compares to the historical event. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2008AGUFMOS43D1341B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2008AGUFMOS43D1341B">Near Source 2007 Peru Tsunami Runup Observations and Modeling</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Borrero, J. C.; Fritz, H. M.; Kalligeris, N.; Broncano, P.; Ortega, E. 2008-12-01 On 15 August 2007 an earthquake with moment magnitude (Mw) of 8.0 centered off the coast of central Peru, generated a tsunami with locally focused runup heights of up to 10 m. A reconnaissance team was deployed two weeks after the event and investigated the tsunami effects at 51 sites. Three tsunami fatalities were reported south of the Paracas Peninsula in a sparsely populated desert area where the largest tsunami runup heights and massive inundation distances up to 2 km were measured. Numerical modeling of the earthquake source and tsunami suggest that a region of high slip near the coastline was primarily responsible for the extreme runup heights. The town of Pisco was spared by the Paracas Peninsula, which blocked tsunami waves from propagating northward from the high slip region. As with all near field tsunamis, the waves struck within minutes of the massive ground shaking. Spontaneous evacuations coordinated by the Peruvian Coast Guard minimized the fatalities and illustrate the importance of community-based education and awareness programs. The residents of the fishing village Lagunilla were unaware of the tsunami hazard after an earthquake and did not evacuate, which resulted in 3 fatalities. Despite the relatively benign tsunami effects at Pisco from this event, the tsunami hazard for this city (and its liquefied natural gas terminal) cannot be underestimated. Between 1687 and 1868, the city of Pisco was destroyed 4 times by tsunami waves. Since then, two events (1974 and 2007) have resulted in partial inundation and moderate damage. The fact that potentially devastating tsunami runup heights were observed immediately south of the peninsula only serves to underscore this point. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFMNH13A0111T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFMNH13A0111T">Quantifying Coastal Hazard of Airburst-Generated Tsunamis</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Titov, V. V.; Boslough, M. 2017-12-01 The effort to prevent or mitigate the effects of an impact on Earth is known as planetary defense. A significant component of planetary defense research involves risk assessment. Much of our understanding of the risk from near-Earth objects comes from the geologic record in the form of impact craters, but not all asteroid impacts are crater-forming events. Small asteroids explode before reaching the surface, generating an airburst, and most impacts into the ocean do not penetrate the water to form a crater in the sea floor. The risk from these non-crater-forming ocean impacts and airbursts is difficult to quantify and represents a significant uncertainty in our assessment of the overall threat. One of the suggested mechanisms for the production of asteroid-generated tsunami is by direct coupling of the pressure wave to the water, analogous to the means by which a moving weather front can generate a meteotsunami. To test this hypothesis, we have run a series of airburst simulations and provided time-resolved pressure and wind profiles for tsunami modelers to use as source functions. We used hydrocodes to model airburst scenarios and provide time dependent boundary conditions as input to shallow-water wave propagation codes. The strongest and most destructive meteotsunami are generated by atmospheric pressure oscillations with amplitudes of only a few hPa, corresponding to changes in sea level of a few cm. The resulting wave is strongest when there is a resonance between the ocean and the atmospheric forcing. The blast wave from an airburst propagates at a speed close to a tsunami speed only in the deepest part of the ocean, and a Proudman resonance cannot be usually achieved even though the overpressures are orders of magnitude greater. However, blast wave profiles are N-waves in which a sharp shock wave leading to overpressure is followed by a more gradual rarefaction to a much longer-duration underpressure phase. Even though the blast outruns the water wave it is </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017PApGe.174.2961Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017PApGe.174.2961Z">The 2011 Tohoku Tsunami on the Coast of Mexico: A Case Study</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Zaytsev, Oleg; Rabinovich, Alexander B.; Thomson, Richard E. 2017-08-01 The Tohoku (East Japan) earthquake of 11 March 2011 ( M w 9.0) generated a great trans-oceanic tsunami that spread throughout the Pacific Ocean, where it was measured by numerous coastal tide gauges and open-ocean DART (Deep-ocean Assessment and Reporting of Tsunamis) stations. Statistical and spectral analyses of the tsunami waves recorded along the Pacific coast of Mexico have enabled us to estimate the principal parameters of the waves along the coast and to compare statistical features of the tsunami with other tsunamis recorded on this coast. We identify coastal "hot spots"—Manzanillo, Zihuatanejo, Acapulco, and Ensenada—corresponding to sites having highest tsunami hazard potential, where wave heights during the 2011 event exceeded 1.5-2 m and tsunami-induced currents were strong enough to close port operations. Based on a joint spectral analysis of the tsunamis and background noise, we reconstructed the spectra of tsunami waves in the deep ocean and found that, with the exception of the high-frequency spectral band (>5 cph), the spectra are in close agreement with the "true" tsunami spectra determined from DART bottom pressure records. The departure of the high-frequency spectra in the coastal region from the deep-sea spectra is shown to be related to background infragravity waves generated in the coastal zone. The total energy and frequency content of the Tohoku tsunami is compared with the corresponding results for the 2010 Chilean tsunami. Our findings show that the integral open-ocean tsunami energy, I 0, was 2.30 cm2, or approximately 1.7 times larger than for the 2010 event. Comparison of this parameter with the mean coastal tsunami variance (451 cm2) indicates that tsunami waves propagating onshore from the open ocean amplified by 14 times; the same was observed for the 2010 tsunami. The "tsunami colour" (frequency content) for the 2011 Tohoku tsunami was "red", with about 65% of the total energy associated with low-frequency waves at frequencies </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016GeoJI.204..719O','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016GeoJI.204..719O">Sequencing of tsunami waves: why the first wave is not always the largest</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Okal, Emile A.; Synolakis, Costas E. 2016-02-01 This paper examines the factors contributing to the `sequencing' of tsunami waves in the far field, that is, to the distribution of the maximum sea surface amplitude inside the dominant wave packet constituting the primary arrival at a distant harbour. Based on simple models of sources for which analytical solutions are available, we show that, as range is increased, the wave pattern evolves from a regime of maximum amplitude in the first oscillation to one of delayed maximum, where the largest amplitude takes place during a subsequent oscillation. In the case of the simple, instantaneous uplift of a circular disk at the surface of an ocean of constant depth, the critical distance for transition between those patterns scales as r_0^3 / h^2 where r0 is the radius of the disk and h the depth of the ocean. This behaviour is explained from simple arguments based on a model where sequencing results from frequency dispersion in the primary wave packet, as the width of its spectrum around its dominant period T0 becomes dispersed in time in an amount comparable to T0, the latter being controlled by a combination of source size and ocean depth. The general concepts in this model are confirmed in the case of more realistic sources for tsunami excitation by a finite-time deformation of the ocean floor, as well as in real-life simulations of tsunamis excited by large subduction events, for which we find that the influence of fault width on the distribution of sequencing is more important than that of fault length. Finally, simulation of the major events of Chile (2010) and Japan (2011) at large arrays of virtual gauges in the Pacific Basin correctly predicts the majority of the sequencing patterns observed on DART buoys during these events. By providing insight into the evolution with time of wave amplitudes inside primary wave packets for far field tsunamis generated by large earthquakes, our results stress the importance, for civil defense authorities, of issuing warning and </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017PrOce.159..296R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017PrOce.159..296R">The tsunami phenomenon</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Röbke, B. R.; Vött, A. 2017-12-01 With human activity increasingly concentrating on coasts, tsunamis (from Japanese tsu = harbour, nami = wave) are a major natural hazard to today's society. Stimulated by disastrous tsunami impacts in recent years, for instance in south-east Asia (2004) or in Japan (2011), tsunami science has significantly flourished, which has brought great advances in hazard assessment and mitigation plans. Based on tsunami research of the last decades, this paper provides a thorough treatise on the tsunami phenomenon from a geoscientific point of view. Starting with the wave features, tsunamis are introduced as long shallow water waves or wave trains crossing entire oceans without major energy loss. At the coast, tsunamis typically show wave shoaling, funnelling and resonance effects as well as a significant run-up and backflow. Tsunami waves are caused by a sudden displacement of the water column due to a number of various trigger mechanisms. Such are earthquakes as the main trigger, submarine and subaerial mass wastings, volcanic activity, atmospheric disturbances (meteotsunamis) and cosmic impacts, as is demonstrated by giving corresponding examples from the past. Tsunamis are known to have a significant sedimentary and geomorphological off- and onshore response. So-called tsunamites form allochthonous high-energy deposits that are left at the coast during tsunami landfall. Tsunami deposits show typical sedimentary features, as basal erosional unconformities, fining-upward and -landward, a high content of marine fossils, rip-up clasts from underlying units and mud caps, all reflecting the hydrodynamic processes during inundation. The on- and offshore behaviour of tsunamis and related sedimentary processes can be simulated using hydro- and morphodynamic numerical models. The paper provides an overview of the basic tsunami modelling techniques, including discretisation, guidelines for appropriate temporal and spatial resolution as well as the nesting method. Furthermore, the </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013EGUGA..15.6397K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013EGUGA..15.6397K">2011 Great East Japan tsunami in Okhotsk Sea region: numerical modelings and observation data</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Kostenko, Irina; Zaytsev, Andrey; Yalciner, Ahmet; Pelinovsky, Efim 2013-04-01 The 11 March, 2011 Great East Japan Earthquake with Mw: 9.0 occurred at 05:46:23 UTC with its epicenter estimated at 38.322_N, 142.369_E, and focal depth of 32 km (USGS, 2011). Tsunami waves propagated in Pacific Ocean to all directions. At Russian coast the highest waves were observed in the Kuril Islands (Malokurilskoye, Kunashir Island) which located in between Pacific ocean and the Okhotsk Sea. Kuril island provides limited transmission of tsunami waves from Pacific ocean. tsunami In 2011 Great East Japan Earthquake and Tsunami event, the maximum amplitude of the tsunami was observed as 3 m in Kuril islands. However, tsunami arrived Okhotsk Sea losing a significant amount of energy. Therefore the tsunami amplitudes at the coast of the Okhotsk Sea were smaller. In order to estimate the level of energy loss while passing through the narrow straits of the Kuril Islands, a series of numerical simulations was done by using tsunami numerical code NAMI DANCE. Ten largest earthquake shocks capable of generating tsunami were used as inputs of tsunami sources in the modeling. Hence the relation between the transmission of tsunami and the dimensions of the straits are compared and discussed. Finally the characteristics of tsunami propagation (arrival time and coastal amplification) at the coast in the Okhotsk Sea. The varying grid structure is used in numerical modeling in order to make finer analysis of tsunami passing through narrow straits of the Kuril Islands. This allows to combine exactly the installation locations of stationary and computational gauges. The simulation results are compared with the observations. The linear form of shallow water equations are used in the deep ocean region offshore part of the Sea of Okhotsk. Boussinesq type equations were also used at the near shore area in simulations. Since the Okhotsk Sea Results are a semi enclosed basin, the reflection characteristics at the coastal boundaries may be important. The numerical experiments are also </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013AGUFMNH52A..07E','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013AGUFMNH52A..07E">Tsunami Hazard Assessment: Source regions of concern to U.S. interests derived from NOAA Tsunami Forecast Model Development</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Eble, M. C.; uslu, B. U.; Wright, L. 2013-12-01 Synthetic tsunamis generated from source regions around the Pacific Basin are analyzed in terms of their relative impact on United States coastal locations.. The region of tsunami origin is as important as the expected magnitude and the predicted inundation for understanding tsunami hazard. The NOAA Center for Tsunami Research has developed high-resolution tsunami models capable of predicting tsunami arrival time and amplitude of waves at each location. These models have been used to conduct tsunami hazard assessments to assess maximum impact and tsunami inundation for use by local communities in education and evacuation map development. Hazard assessment studies conducted for Los Angeles, San Francisco, Crescent City, Hilo, and Apra Harbor are combined with results of tsunami forecast model development at each of seventy-five locations. Complete hazard assessment, identifies every possible tsunami variation from a pre-computed propagation database. Study results indicate that the Eastern Aleutian Islands and Alaska are the most likely regions to produce the largest impact on the West Coast of the United States, while the East Philippines and Mariana trench regions impact Apra Harbor, Guam. Hawaii appears to be impacted equally from South America, Alaska and the Kuril Islands. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018PApGe.175.1371S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018PApGe.175.1371S">Ray Tracing for Dispersive Tsunamis and Source Amplitude Estimation Based on Green's Law: Application to the 2015 Volcanic Tsunami Earthquake Near Torishima, South of Japan</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Sandanbata, Osamu; Watada, Shingo; Satake, Kenji; Fukao, Yoshio; Sugioka, Hiroko; Ito, Aki; Shiobara, Hajime 2018-04-01 Ray tracing, which has been widely used for seismic waves, was also applied to tsunamis to examine the bathymetry effects during propagation, but it was limited to linear shallow-water waves. Green's law, which is based on the conservation of energy flux, has been used to estimate tsunami amplitude on ray paths. In this study, we first propose a new ray tracing method extended to dispersive tsunamis. By using an iterative algorithm to map two-dimensional tsunami velocity fields at different frequencies, ray paths at each frequency can be traced. We then show that Green's law is valid only outside the source region and that extension of Green's law is needed for source amplitude estimation. As an application example, we analyzed tsunami waves generated by an earthquake that occurred at a submarine volcano, Smith Caldera, near Torishima, Japan, in 2015. The ray-tracing results reveal that the ray paths are very dependent on its frequency, particularly at deep oceans. The validity of our frequency-dependent ray tracing is confirmed by the comparison of arrival angles and travel times with those of observed tsunami waveforms at an array of ocean bottom pressure gauges. The tsunami amplitude at the source is nearly twice or more of that just outside the source estimated from the array tsunami data by Green's law. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013EGUGA..15.6373A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013EGUGA..15.6373A">Advanced Geospatial Hydrodynamic Signals Analysis for Tsunami Event Detection and Warning</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Arbab-Zavar, Banafshe; Sabeur, Zoheir 2013-04-01 Current early tsunami warning can be issued upon the detection of a seismic event which may occur at a given location offshore. This also provides an opportunity to predict the tsunami wave propagation and run-ups at potentially affected coastal zones by selecting the best matching seismic event from a database of pre-computed tsunami scenarios. Nevertheless, it remains difficult and challenging to obtain the rupture parameters of the tsunamigenic earthquakes in real time and simulate the tsunami propagation with high accuracy. In this study, we propose a supporting approach, in which the hydrodynamic signal is systematically analysed for traces of a tsunamigenic signal. The combination of relatively low amplitudes of a tsunami signal at deep waters and the frequent occurrence of background signals and noise contributes to a generally low signal to noise ratio for the tsunami signal; which in turn makes the detection of this signal difficult. In order to improve the accuracy and confidence of detection, a re-identification framework in which a tsunamigenic signal is detected via the scan of a network of hydrodynamic stations with water level sensing is performed. The aim is to attempt the re-identification of the same signatures as the tsunami wave spatially propagates through the hydrodynamic stations sensing network. The re-identification of the tsunamigenic signal is technically possible since the tsunami signal at the open ocean itself conserves its birthmarks relating it to the source event. As well as supporting the initial detection and improving the confidence of detection, a re-identified signal is indicative of the spatial range of the signal, and thereby it can be used to facilitate the identification of certain background signals such as wind waves which do not have as large a spatial reach as tsunamis. In this paper, the proposed methodology for the automatic detection of tsunamigenic signals has been achieved using open data from NOAA with a recorded </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AGUFMNH43B1860G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUFMNH43B1860G">Quantification of uncertainties in the tsunami hazard for Cascadia using statistical emulation</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Guillas, S.; Day, S. J.; Joakim, B. 2016-12-01 We present new high resolution tsunami wave propagation and coastal inundation for the Cascadia region in the Pacific Northwest. The coseismic representation in this analysis is novel, and more realistic than in previous studies, as we jointly parametrize multiple aspects of the seabed deformation. Due to the large computational cost of such simulators, statistical emulation is required in order to carry out uncertainty quantification tasks, as emulators efficiently approximate simulators. The emulator replaces the tsunami model VOLNA by a fast surrogate, so we are able to efficiently propagate uncertainties from the source characteristics to wave heights, in order to probabilistically assess tsunami hazard for Cascadia. We employ a new method for the design of the computer experiments in order to reduce the number of runs while maintaining good approximations properties of the emulator. Out of the initial nine parameters, mostly describing the geometry and time variation of the seabed deformation, we drop two parameters since these turn out to not have an influence on the resulting tsunami waves at the coast. We model the impact of another parameter linearly as its influence on the wave heights is identified as linear. We combine this screening approach with the sequential design algorithm MICE (Mutual Information for Computer Experiments), that adaptively selects the input values at which to run the computer simulator, in order to maximize the expected information gain (mutual information) over the input space. As a result, the emulation is made possible and accurate. Starting from distributions of the source parameters that encapsulate geophysical knowledge of the possible source characteristics, we derive distributions of the tsunami wave heights along the coastline. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016EGUGA..1811285M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016EGUGA..1811285M">Scenario based tsunami wave height estimation towards hazard evaluation for the Hellenic coastline and examples of extreme inundation zones in South Aegean</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Melis, Nikolaos S.; Barberopoulou, Aggeliki; Frentzos, Elias; Krassanakis, Vassilios 2016-04-01 A scenario based methodology for tsunami hazard assessment is used, by incorporating earthquake sources with the potential to produce extreme tsunamis (measured through their capacity to cause maximum wave height and inundation extent). In the present study we follow a two phase approach. In the first phase, existing earthquake hazard zoning in the greater Aegean region is used to derive representative maximum expected earthquake magnitude events, with realistic seismotectonic source characteristics, and of greatest tsunamigenic potential within each zone. By stacking the scenario produced maximum wave heights a global maximum map is constructed for the entire Hellenic coastline, corresponding to all expected extreme offshore earthquake sources. Further evaluation of the produced coastline categories based on the maximum expected wave heights emphasizes the tsunami hazard in selected coastal zones with important functions (i.e. touristic crowded zones, industrial zones, airports, power plants etc). Owing to its proximity to the Hellenic Arc, many urban centres and being a popular tourist destination, Crete Island and the South Aegean region are given a top priority to define extreme inundation zoning. In the second phase, a set of four large coastal cities (Kalamata, Chania, Heraklion and Rethymno), important for tsunami hazard, due i.e. to the crowded beaches during the summer season or industrial facilities, are explored towards preparedness and resilience for tsunami hazard in Greece. To simulate tsunamis in the Aegean region (generation, propagation and runup) the MOST - ComMIT NOAA code was used. High resolution DEMs for bathymetry and topography were joined via an interface, specifically developed for the inundation maps in this study and with similar products in mind. For the examples explored in the present study, we used 5m resolution for the topography and 30m resolution for the bathymetry, respectively. Although this study can be considered as </li> <li> <a target="_blank" onclick="trackOutboundLink('http://www.dtic.mil/docs/citations/ADA627138','DTIC-ST'); return false;" href="http://www.dtic.mil/docs/citations/ADA627138">Observation and Modeling of Tsunami-Generated Gravity Waves in the Earth’s Upper Atmosphere</a> <a target="_blank" href="http://www.dtic.mil/">DTIC Science & Technology</a> 2015-10-08 Observation and modeling of tsunami -generated gravity waves in the earth’s upper atmosphere 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6...ABSTRACT Build a compatible set of models which 1) calculate the spectrum of atmospheric GWs excited by a tsunami (using ocean model data as input...for public release; distribution is unlimited. Observation and modeling of tsunami -generated gravity waves in the earth’s upper atmosphere Sharon </li> <li> <a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20170004626','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20170004626">Contribution of Asteroid Generated Tsunami to the Impact Hazard</a> <a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a> Morrison, David; Venkatapathy, Ethiraj 2017-01-01 The long-standing uncertainty about the importance of asteroid-generated tsunami was addressed at a workshop in August 2016, co-sponsored by NASA and NOAA. Experts from NASA, NOAA, the DoE tri-labs (LLNL, SNL, and LANL), DHS, FEMA, and academia addressed the hazard of tsunami created by asteroid impacts, focusing primarily on NEAs with diameter less than 250m. Participants jointly identified key issues and shared information for nearly a year to coordinate their results for discussion at the workshop. They used modern computational tools to examine 1) Near-field wave generation by the impact; 2) Long-distance wave propagation; 3) Damage from coastal run-up and inundation, and associated hazard. The workshop resulted in broad consensus that the asteroid impact tsunami threat is not as great as previously thought. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFMNH23A0218O','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFMNH23A0218O">Landslide Tsunami Hazard in Madeira Island, NE Atlantic - Numerical Simulation of the 4 March 1930 Tsunami</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Omira, R.; Baptista, M. A.; Quartau, R.; Ramalho, M. I. 2017-12-01 Madeira, the main Island of the Madeira Archipelago with an area of 728 km2, is a North East Atlantic volcanic Island highly susceptible to cliff instability. Historical records contain accounts of a number of mass-wasting events along the Island, namely in 1969, 1804, 1929 and 1930. Collapses of cliffs are major hazards in oceanic Islands as they involve relatively large volumes of material, generating fast running debris avalanches, and even cause destructive tsunamis when entering the sea. On March 4th, 1930, a sector of the Cape Girão cliff, located in the southern shore of Madeira Island, collapsed into the sea and generated an 8 m tsunami wave height. The landslide-induced tsunami propagated along Madeirás south coast and flooded the Vigário beach, 200-300 m of inundation extent, causing 20 casualties. In this study, we investigate the 1930 subaerial landslide-induced tsunami and its impact on the nearest coasts using numerical modelling. We first reconstruct the pre-event morphology of the area, and then simulate the initial movement of the sliding mass, the propagation of the tsunami wave and the inundation of the coast. We use a multi-layer numerical model, in which the lower layer represents the deformable slide, assumed to be a visco-plastic fluid, and bounded above by air, in the subaerial motion phase, and by seawater governed by shallow water equations. The results of the simulation are compared with the historical descriptions of the event to calibrate the numerical model and evaluate the coastal impact of a similar event in present-day coastline configuration of the Island. This work is supported by FCT- project UID/GEO/50019/2013 - Instituto Dom Luiz and by TROYO project. </li> <li> <a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20030111299&hterms=tsunami&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Dtsunami','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20030111299&hterms=tsunami&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Dtsunami">Impact-generated Tsunamis: An Over-rated Hazard</a> <a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a> Melosh, H. J. 2003-01-01 A number of authors have suggested that oceanic waves (tsunami) created by the impact of relatively small asteroids into the Earth's oceans might cause widespread devastation to coastal cities. If correct, this suggests that asteroids > 100 m in diameter may pose a serious hazard to humanity and could require a substantial expansion of the current efforts to identify earth-crossing asteroids > 1 km in diameter. The debate on this hazard was recently altered by the release of a document previously inaccessible to the scientific community. In 1968 the US Office of Naval Research commissioned a summary of several decades of research into the hazard proposed by waves generated by nuclear explosions in the ocean. Authored by tsunami expert William Van Dorn, this 173-page report entitled Handbook of Explosion-Generated Water Waves affords new insight into the process of impact wave formation, propagation, and run up onto the shoreline. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013EGUGA..1511690K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013EGUGA..1511690K">GPS-TEC of the Ionospheric Disturbances as a Tool for Early Tsunami Warning</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Kunitsyn, Viacheslav E.; Nesterov, Ivan A.; Shalimov, Sergey L.; Krysanov, Boris Yu.; Padokhin, Artem M.; Rekenthaler, Douglas 2013-04-01 Recently, the GPS measurements were used for retrieving the information on the various types of ionospheric responses to seismic events (earthquakes, seismic Rayleigh waves, and tsunami) which generate atmospheric waves propagating up to the ionospheric altitudes where the collisions between the neutrals and charge particles give rise to the motion of the ionospheric plasma. These experimental results can well be used in architecture of the future tsunami warning system. The point is an earlier (in comparison with seismological methods) detection of the ionospheric signal that can indicate the moment of tsunami generation. As an example we consider the two-dimensional distributions of the vertical total electron content (TEC) variations in the ionosphere both close to and far from the epicenter of the Japan undersea earthquake of March 11, 2011 using radio tomographic (RT) reconstruction of high-temporal-resolution (2-minute) data from the Japan and the US GPS networks. Near-zone TEC variations shows a diverging ionospheric perturbation with multi-component spectral composition emerging after the main shock. The initial phase of the disturbance can be used as an indicator of the tsunami generation and subsequently for the tsunami early warning. Far-zone TEC variations reveals distinct wave train associated with gravity waves generated by tsunami. According to observations tsunami arrives at Hawaii and further at the coast of Southern California with delay relative to the gravity waves. Therefore the gravity wave pattern can be used in the early tsunami warning. We support this scenario by the results of modeling with the parameters of the ocean surface perturbation corresponding to the considered earthquake. In addition it was observed in the modeling that at long distance from the source the gravity wave can pass ahead of the tsunami. The work was supported by the Russian Foundation for Basic Research (grants 11-05-01157 and 12-05-33065). </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014EGUGA..16.6375K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014EGUGA..16.6375K">Fast algorithm for calculation of the moving tsunami wave height</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Krivorotko, Olga; Kabanikhin, Sergey 2014-05-01 One of the most urgent problems of mathematical tsunami modeling is estimation of a tsunami wave height while a wave approaches to the coastal zone. There are two methods for solving this problem, namely, Airy-Green formula in one-dimensional case ° --- S(x) = S(0) 4 H(0)/H (x), and numerical solution of an initial-boundary value problem for linear shallow water equations ( { ηtt = div (gH (x,y)gradη), (x,y,t) ∈ ΩT := Ω ×(0,T); ( η|t=0 = q(x,y), ηt|t=0 = 0, (x,y ) ∈ Ω := (0,Lx)× (0,Ly ); (1) η|δΩT = 0. Here η(x,y,t) is the free water surface vertical displacement, H(x,y) is the depth at point (x,y), q(x,y) is the initial amplitude of a tsunami wave, S(x) is a moving tsunami wave height at point x. The main difficulty problem of tsunami modeling is a very big size of the computational domain ΩT. The calculation of the function η(x,y,t) of three variables in ΩT requires large computing resources. We construct a new algorithm to solve numerically the problem of determining the moving tsunami wave height which is based on kinematic-type approach and analytical representation of fundamental solution (2). The wave is supposed to be generated by the seismic fault of the bottom η(x,y,0) = g(y) ·θ(x), where θ(x) is a Heaviside theta-function. Let τ(x,y) be a solution of the eikonal equation 1 τ2x +τ2y = --, gH (x,y) satisfying initial conditions τ(0,y) = 0 and τx(0,y) = (gH (0,y))-1/2. Introducing new variables and new functions: ° -- z = τ(x,y), u(z,y,t) = ηt(x,y,t), b(z,y) = gH(x,y). We obtain an initial-boundary value problem in new variables from (1) ( 2 2 (2 bz- ) { utt = uzz + b uyy + 2b τyuzy + b(τxx + τyy) + 2b + 2bbyτy uz+ ( +2b(bzτy + by)uy, z,y- >2 0,t > 0,2 -1/2 u|t 0,t > 0. Then after some mathematical transformation we get the structure of the function u(x,y,t) in the form u(z,y,t) = S(z,y)·θ(t - z) + ˜u(z,y,t). (2) Here Å©(z,y,t) is a smooth function, S(z,y) is the solution of the problem: { S + b2τ S + (1b2(τ +� </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_5");'>5</a></li> <li><a href="#" onclick='return showDiv("page_6");'>6</a></li> <li class="active">7</li> <li><a href="#" onclick='return showDiv("page_8");'>8</a></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> </div> <div id="page_8" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_6");'>6</a></li> <li><a href="#" onclick='return showDiv("page_7");'>7</a></li> <li class="active">8</li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="141"> <li> <a target="_blank" onclick="trackOutboundLink('https://images.nasa.gov/#/details-PIA04373.html','SCIGOVIMAGE-NASA'); return false;" href="https://images.nasa.gov/#/details-PIA04373.html">Deep Ocean Tsunami Waves off the Sri Lankan Coast</a> <a target="_blank" href="https://images.nasa.gov/">NASA Image and Video Library</a> 2005-01-26 The initial tsunami waves resulting from the undersea earthquake that occurred at 00:58:53 UTC Coordinated Universal Time on 26 December 2004 off the island of Sumatra, Indonesia, as seen by NASA Terra spacecraft. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013AGUFMNH53A..04W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013AGUFMNH53A..04W">Tsunami Speed Variations in Density-stratified Compressible Global Oceans</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Watada, S. 2013-12-01 Recent tsunami observations in the deep ocean have accumulated unequivocal evidence that tsunami traveltime delays compared with the linear long-wave tsunami simulations occur during tsunami propagation in the deep ocean. The delay is up to 2% of the tsunami traveltime. Watada et al. [2013] investigated the cause of the delay using the normal mode theory of tsunamis and attributed the delay to the compressibility of seawater, the elasticity of the solid earth, and the gravitational potential change associated with mass motion during the passage of tsunamis. Tsunami speed variations in the deep ocean caused by seawater density stratification is investigated using a newly developed propagator matrix method that is applicable to seawater with depth-variable sound speeds and density gradients. For a 4-km deep ocean, the total tsunami speed reduction is 0.45% compared with incompressible homogeneous seawater; two thirds of the reduction is due to elastic energy stored in the water and one third is due to water density stratification mainly by hydrostatic compression. Tsunami speeds are computed for global ocean density and sound speed profiles and characteristic structures are discussed. Tsunami speed reductions are proportional to ocean depth with small variations, except for in warm Mediterranean seas. The impacts of seawater compressibility and the elasticity effect of the solid earth on tsunami traveltime should be included for precise modeling of trans-oceanic tsunamis. Data locations where a vertical ocean profile deeper than 2500 m is available in World Ocean Atlas 2009. The dark gray area indicates the Pacific Ocean defined in WOA09. a) Tsunami speed variations. Red, gray and black bars represent global, Pacific, and Mediterranean Sea, respectively. b) Regression lines of the tsunami velocity reduction for all oceans. c)Vertical ocean profiles at grid points indicated by the stars in Figure 1. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011AGUFMSA21B..01M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011AGUFMSA21B..01M">Imaging, radio, and modeling results pertaining to the ionospheric signature of the 11 March 2011 tsunami over the Pacific Ocean</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Makela, J. J.; Lognonne, P.; Occhipinti, G.; Hebert, H.; Gehrels, T.; Coisson, P.; Rolland, L. M.; Allgeyer, S.; Kherani, A. 2011-12-01 The Mw=9.0 earthquake that occurred off the east coast of Honshu, Japan on 11 March 2011 launched a tsunami that traveled across the Pacific Ocean, in turn launching vertically propagating atmospheric gravity waves. Upon reaching 250-350 km in altitude, these waves impressed their signature on the thermosphere/ionosphere system. We present observations of this signature obtained using a variety of radio instruments and an imaging system located on the islands of Hawaii. These measurements represent the first optical images recorded of the airglow signature resulting from the passage of a tsunami. Results from these instruments clearly show wave structure propagating in the upper atmosphere with the same velocity as the ocean tsunami, emphasizing the coupled nature of the ocean, atmosphere, and ionosphere. Modeling results are also presented to highlight current understandings of this coupling process. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2008GeoRL..3510604F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2008GeoRL..3510604F">The 15 August 2007 Peru tsunami runup observations and modeling</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Fritz, Hermann M.; Kalligeris, Nikos; Borrero, Jose C.; Broncano, Pablo; Ortega, Erick 2008-05-01 On 15 August 2007 an earthquake with moment magnitude (Mw) of 8.0 centered off the coast of central Peru, generated a tsunami with locally focused runup heights of up to10 m. A reconnaissance team was deployed two weeks after the event and investigated the tsunami effects at 51 sites. Three tsunami fatalities were reported south of the Paracas Peninsula in a sparsely populated desert area where the largest tsunami runup heights were measured. Numerical modeling of the earthquake source and tsunami suggest that a region of high slip near the coastline was primarily responsible for the extreme runup heights. The town of Pisco was spared by the Paracas Peninsula, which blocked tsunami waves from propagating northward from the high slip region. The coast of Peru has experienced numerous deadly and destructive tsunamis throughout history, which highlights the importance of ongoing tsunami awareness and education efforts to ensure successful self-evacuation. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2006AGUFM.U53C..06H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2006AGUFM.U53C..06H">Estimating Seismic Moment From Broadband P-Waves for Tsunami Warnings.</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Hirshorn, B. F. 2006-12-01 The Richard H. Hagemeyer Pacific Tsunami Warning Center (PTWC), located in Ewa Beach, Oahu, Hawaii, is responsible for issuing local, regional, and distant tsunami warnings to Hawaii, and for issuing regional and distant tsunami warnings to the rest of the Pacific Basin, exclusive of the US West Coast. The PTWC must provide these tsunami warnings as soon as technologically possible, based entirely on estimates of a potentially tsunamigenic earthquake's source parameters. We calculate the broadband P-wave moment magnitude, Mwp, from the P or pP wave velocity seismograms [Tsuboi et al., 1995, 1999]. This method appears to work well for regional and teleseismic events [ Tsuboi et al (1999], Whitmore et al (2002), Hirshorn et al (2004) ]. Following Tsuboi, [1995], we consider the displacement record of the P-wave portion of the broadband seismograms as an approximate source time function and integrate this record to obtain the moment rate function, Mo(t), and the moment magnitude [Hanks and Kanamori, 1972] as a function of time, Mw(t). We present results for Mwp for local, regional, and teleseismic broad band recordings for earthquakes in the Mw 5 to 9.3 range. As large Hawaii events are rare, we tested this local case using other Pacific events in the magnitude 5.0 to 7.5 range recorded by nearby stations. Signals were excluded, however, if the epicentral distance was so small (generally less than 1 degree) that there was contamination by the S-wave too closely following the P-waves. Scatter plots of Mwp against the Harvard Mw for these events shows that Mwp does predict Mw well from seismograms recorded at local, regional, and teleseismic distances. For some complex earthquakes, eg. the Mw 8.4(HRV) Peru earthquake of June 21, 2001, Mwp underestimates Mw if the first moment release is not the largest. Our estimates of Mwp for the Mw 9.3 Summatra-Andaman Island's earthquake of December 26, 2004 and for the Mw 8.7 (HRV) Summatra event of March 28, 2005, were Mwp 8 </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017EGUGA..1912891R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017EGUGA..1912891R">Combining historical eyewitness accounts on tsunami-induced waves and numerical simulations for getting insights in uncertainty of source parameters</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Rohmer, Jeremy; Rousseau, Marie; Lemoine, Anne; Pedreros, Rodrigo; Lambert, Jerome; benki, Aalae 2017-04-01 Recent tsunami events including the 2004 Indian Ocean tsunami and the 2011 Tohoku tsunami have caused many casualties and damages to structures. Advances in numerical simulation of tsunami-induced wave processes have tremendously improved forecast, hazard and risk assessment and design of early warning for tsunamis. Among the major challenges, several studies have underlined uncertainties in earthquake slip distributions and rupture processes as major contributor on tsunami wave height and inundation extent. Constraining these uncertainties can be performed by taking advantage of observations either on tsunami waves (using network of water level gauge) or on inundation characteristics (using field evidence and eyewitness accounts). Despite these successful applications, combining tsunami observations and simulations still faces several limitations when the problem is addressed for past tsunamis events like 1755 Lisbon. 1) While recent inversion studies can benefit from current modern networks (e.g., tide gauges, sea bottom pressure gauges, GPS-mounted buoys), the number of tide gauges can be very scarce and testimonies on tsunami observations can be limited, incomplete and imprecise for past tsunamis events. These observations often restrict to eyewitness accounts on wave heights (e.g., maximum reached wave height at the coast) instead of the full observed waveforms; 2) Tsunami phenomena involve a large span of spatial scales (from ocean basin scales to local coastal wave interactions), which can make the modelling very demanding: the computation time cost of tsunami simulation can be very prohibitive; often reaching several hours. This often limits the number of allowable long-running simulations for performing the inversion, especially when the problem is addressed from a Bayesian inference perspective. The objective of the present study is to overcome both afore-described difficulties in the view to combine historical observations on past tsunami-induced waves </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016JIEIC..97..493A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016JIEIC..97..493A">New Offshore Approach to Reduce Impact of Tsunami Waves</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Anant Chatorikar, Kaustubh 2016-07-01 The world is facing an increasing frequency and intensity of natural disaster that has devastating impacts on society. As per International Strategy for Disaster Reduction (ISDR), it has been observed that over five million people were killed or affected in last 10 years and huge amount of economic losses occurred due to natural disaster. The 2011 tsunami in Japan showed a tremendous setback to existing technology of tsunami protection. More than 25,000 lives have been lost, Apart from that the damage to the nuclear power stations has severely affected the nearby populace and marine life. After the 2004 tsunami, world's effort has been concentrated on early warning and effective mitigation plans to defend against tsunami. It is anybody's guess as to what would have happened if such natural calamity specifically tsunami of such magnitude strikes our nation as country has already suffered from it in 2004 and seen its disastrous effects. But the point is what if such calamity strikes the mega cities like Chennai, Mumbai and Kolkata again where there is extensive human habitation and conventional warning systems and mitigation methods are not effective when it comes to huge population of these cities, destruction caused by it will be worse than nuclear weapon strike as there is also very high possibility of deaths due to stampede. This paper talks about an idea inspired from daily routine and its relation with fundamental physics as well as method of its deployment is discussed. According to this idea when wave will strike the coast, aim is not to stop it but to reduce its impact within the permissible impact limits of existing infrastructure by converting it into foam wave with help of surfactants, thereby saving human lives as well as complications of Mitigation. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013AGUFMPA43B2041B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013AGUFMPA43B2041B">Scientific Animations for Tsunami Hazard Mitigation: The Pacific Tsunami Warning Center's YouTube Channel</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Becker, N. C.; Wang, D.; Shiro, B.; Ward, B. 2013-12-01 Outreach and education save lives, and the Pacific Tsunami Warning Center (PTWC) has a new tool--a YouTube Channel--to advance its mission to protect lives and property from dangerous tsunamis. Such outreach and education is critical for coastal populations nearest an earthquake since they may not get an official warning before a tsunami reaches them and will need to know what to do when they feel strong shaking. Those who live far enough away to receive useful official warnings and react to them, however, can also benefit from PTWC's education and outreach efforts. They can better understand a tsunami warning message when they receive one, can better understand the danger facing them, and can better anticipate how events will unfold while the warning is in effect. The same holds true for emergency managers, who have the authority to evacuate the public they serve, and for the news media, critical partners in disseminating tsunami hazard information. PTWC's YouTube channel supplements its formal outreach and education efforts by making its computer animations available 24/7 to anyone with an Internet connection. Though the YouTube channel is only a month old (as of August 2013), it should rapidly develop a large global audience since similar videos on PTWC's Facebook page have reached over 70,000 viewers during organized media events, while PTWC's official web page has received tens of millions of hits during damaging tsunamis. These animations are not mere cartoons but use scientific data and calculations to render graphical depictions of real-world phenomena as accurately as possible. This practice holds true whether the animation is a simple comparison of historic earthquake magnitudes or a complex simulation cycling through thousands of high-resolution data grids to render tsunami waves propagating across an entire ocean basin. PTWC's animations fall into two broad categories. The first group illustrates concepts about seismology and how it is critical to </li> <li> <a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70173968','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70173968">Beat-the-wave evacuation mapping for tsunami hazards in Seaside, Oregon, USA</a> <a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a> Priest, George R.; Stimely, Laura; Wood, Nathan J.; Madin, Ian; Watzig, Rudie 2016-01-01 Previous pedestrian evacuation modeling for tsunamis has not considered variable wave arrival times or critical junctures (e.g., bridges), nor does it effectively communicate multiple evacuee travel speeds. We summarize an approach that identifies evacuation corridors, recognizes variable wave arrival times, and produces a map of minimum pedestrian travel speeds to reach safety, termed a “beat-the-wave” (BTW) evacuation analysis. We demonstrate the improved approach by evaluating difficulty of pedestrian evacuation of Seaside, Oregon, for a local tsunami generated by a Cascadia subduction zone earthquake. We establish evacuation paths by calculating the least cost distance (LCD) to safety for every grid cell in a tsunami-hazard zone using geospatial, anisotropic path distance algorithms. Minimum BTW speed to safety on LCD paths is calculated for every grid cell by dividing surface distance from that cell to safety by the tsunami arrival time at safety. We evaluated three scenarios of evacuation difficulty: (1) all bridges are intact with a 5-minute evacuation delay from the start of earthquake, (2) only retrofitted bridges are considered intact with a 5-minute delay, and (3) only retrofitted bridges are considered intact with a 10-minute delay. BTW maps also take into account critical evacuation points along complex shorelines (e.g., peninsulas, bridges over shore-parallel estuaries) where evacuees could be caught by tsunami waves. The BTW map is able to communicate multiple pedestrian travel speeds, which are typically visualized by multiple maps with current LCD-based mapping practices. Results demonstrate that evacuation of Seaside is problematic seaward of the shore-parallel waterways for those with any limitations on mobility. Tsunami vertical-evacuation refuges or additional pedestrian bridges may be effective ways of reducing loss of life seaward of these waterways. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFMNH23A0248G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFMNH23A0248G">Evaluation of Tsunami Run-Up on Coastal Areas at Regional Scale</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> González, M.; Aniel-Quiroga, Í.; Gutiérrez, O. 2017-12-01 Tsunami hazard assessment is tackled by means of numerical simulations, giving as a result, the areas flooded by tsunami wave inland. To get this, some input data is required, i.e., the high resolution topobathymetry of the study area, the earthquake focal mechanism parameters, etc. The computational cost of these kinds of simulations are still excessive. An important restriction for the elaboration of large scale maps at National or regional scale is the reconstruction of high resolution topobathymetry on the coastal zone. An alternative and traditional method consists of the application of empirical-analytical formulations to calculate run-up at several coastal profiles (i.e. Synolakis, 1987), combined with numerical simulations offshore without including coastal inundation. In this case, the numerical simulations are faster but some limitations are added as the coastal bathymetric profiles are very simply idealized. In this work, we present a complementary methodology based on a hybrid numerical model, formed by 2 models that were coupled ad hoc for this work: a non-linear shallow water equations model (NLSWE) for the offshore part of the propagation and a Volume of Fluid model (VOF) for the areas near the coast and inland, applying each numerical scheme where they better reproduce the tsunami wave. The run-up of a tsunami scenario is obtained by applying the coupled model to an ad-hoc numerical flume. To design this methodology, hundreds of worldwide topobathymetric profiles have been parameterized, using 5 parameters (2 depths and 3 slopes). In addition, tsunami waves have been also parameterized by their height and period. As an application of the numerical flume methodology, the coastal parameterized profiles and tsunami waves have been combined to build a populated database of run-up calculations. The combination was tackled by means of numerical simulations in the numerical flume The result is a tsunami run-up database that considers real profiles shape </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2008AGUFMOS43D1334S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2008AGUFMOS43D1334S">The Contribution of Coseismic Displacements due to Splay Faults Into the Local Wavefield of the 1964 Alaska Tsunami</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Suleimani, E.; Ruppert, N.; Fisher, M.; West, D.; Hansen, R. 2008-12-01 The Alaska Earthquake Information Center conducts tsunami inundation mapping for coastal communities in Alaska. For many locations in the Gulf of Alaska, the 1964 tsunami generated by the Mw9.2 Great Alaska earthquake may be the worst-case tsunami scenario. We use the 1964 tsunami observations to verify our numerical model of tsunami propagation and runup, therefore it is essential to use an adequate source function of the 1964 earthquake to reduce the level of uncertainty in the modeling results. It was shown that the 1964 co-seismic slip occurred both on the megathrust and crustal splay faults (Plafker, 1969). Plafker (2006) suggested that crustal faults were a major contributor to vertical displacements that generated local tsunami waves. Using eyewitness arrival times of the highest observed waves, he suggested that the initial tsunami wave was higher and closer to the shore, than if it was generated by slip on the megathrust. We conduct a numerical study of two different source functions of the 1964 tsunami to test whether the crustal splay faults had significant effects on local tsunami runup heights and arrival times. The first source function was developed by Johnson et al. (1996) through joint inversion of the far-field tsunami waveforms and geodetic data. The authors did not include crustal faults in the inversion, because the contribution of these faults to the far-field tsunami was negligible. The second is the new coseismic displacement model developed by Suito and Freymueller (2008, submitted). This model extends the Montague Island fault farther along the Kenai Peninsula coast and thus reduces slip on the megathrust in that region. We also use an improved geometry of the Patton Bay fault based on the deep crustal seismic reflection and earthquake data. We propagate tsunami waves generated by both source models across the Pacific Ocean and record wave amplitudes at the locations of the tide gages that recorded the 1964 tsunami. As expected, the two </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AGUFMNH43B1846G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUFMNH43B1846G">Tsunami hazard assessment at Port Alberni, BC, Canada: preliminary model results</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Grilli, S. T.; Insua, T. L.; Grilli, A. R.; Douglas, K. L.; Shelby, M. R.; Wang, K.; Gao, D. 2016-12-01 Located in the heart of Vancouver Island, BC, Port Alberni has a well-known history of tsunamis. Many of the Nuu-Chah-Nulth First Nations share oral stories about a strong fight between a thunderbird and a whale that caused big waves in a winter night, a story that is compatible with the recently recognized great Cascadia tsunami in January, 1700. Port Alberni, with a total population of approximately 20,000 people, lies beside the Somass River, at the very end of Barkley Sound Inlet. The narrow canal connecting this town to the Pacific Ocean runs for more than 64 km ( 40 miles) between steep mountains, providing an ideal setting for the amplification of tsunami waves through funnelling effects. The devastating effects of tsunamis are still fresh in residents' memories from the impact of the 1964 Alaska tsunami that caused serious damage to the city. In June 2016, Emergency Management BC ran a coastal exercise in Port Alberni, simulating the response to an earthquake and a tsunami. During three days, the emergency teams in the City of Port Alberni practiced and learned from the experience. Ocean Networks Canada contributed to this exercise with the development of preliminary simulations of tsunami impact on the city from a buried rupture of the Cascadia Subduction Zone, including the Explorer segment. Wave propagation was simulated with the long-wave model FUNWAVE-TVD. Preliminary results indicate a strong amplification of tsunami waves in the Port Alberni area. The inundation zone in Port Alberni had a footprint similar to that of the 1700 Cascadia and 1964 Alaska tsunamis, inundating the area surrounding the Somass river and preferentially following the Kitsuksis and Roger Creek river margins into the city. Several other tsunami source scenarios, including splay faulting and trench-breaching ruptures are currently being modeled for the city of Port Alberni following a similar approach. These results will be presented at the conference. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009JGRC..11412025T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009JGRC..11412025T">Development, testing, and applications of site-specific tsunami inundation models for real-time forecasting</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Tang, L.; Titov, V. V.; Chamberlin, C. D. 2009-12-01 The study describes the development, testing and applications of site-specific tsunami inundation models (forecast models) for use in NOAA's tsunami forecast and warning system. The model development process includes sensitivity studies of tsunami wave characteristics in the nearshore and inundation, for a range of model grid setups, resolutions and parameters. To demonstrate the process, four forecast models in Hawaii, at Hilo, Kahului, Honolulu, and Nawiliwili are described. The models were validated with fourteen historical tsunamis and compared with numerical results from reference inundation models of higher resolution. The accuracy of the modeled maximum wave height is greater than 80% when the observation is greater than 0.5 m; when the observation is below 0.5 m the error is less than 0.3 m. The error of the modeled arrival time of the first peak is within 3% of the travel time. The developed forecast models were further applied to hazard assessment from simulated magnitude 7.5, 8.2, 8.7 and 9.3 tsunamis based on subduction zone earthquakes in the Pacific. The tsunami hazard assessment study indicates that use of a seismic magnitude alone for a tsunami source assessment is inadequate to achieve such accuracy for tsunami amplitude forecasts. The forecast models apply local bathymetric and topographic information, and utilize dynamic boundary conditions from the tsunami source function database, to provide site- and event-specific coastal predictions. Only by combining a Deep-ocean Assessment and Reporting of Tsunami-constrained tsunami magnitude with site-specific high-resolution models can the forecasts completely cover the evolution of earthquake-generated tsunami waves: generation, deep ocean propagation, and coastal inundation. Wavelet analysis of the tsunami waves suggests the coastal tsunami frequency responses at different sites are dominated by the local bathymetry, yet they can be partially related to the locations of the tsunami sources. The study </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009EGUGA..11.3162O','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009EGUGA..11.3162O">Tsunami Impact in Morocco due to Most Credible Tsunami Scenarios in the Gulf of Cadiz.</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Omira, R.; Baptista, M. A.; Miranda, J. M.; Toto, E. A. 2009-04-01 In the Gulf of Cadiz, the tsunami risk should be considered major due to the peculiar geological context close to the Nubia-Eurasia plate boundary and also to the high vulnerability of the coastlines in the region. The extensive occupation of coastal areas in the surrounding countries - Portugal, Spain and Morocco, the enormous influxes of tourists during high season and the large economic value of harbors and other coastal facilities increase considerably the vulnerability to tsunami impact. In order to establish the Most Credible Tsunami Scenarios we used the earthquake scenarios in the Gulf of Cadiz area. Each scenario has an associated typical fault/or faults and a set of fault parameters that are used as input to compute the sea bottom deformation using Okada's equations. Tsunami propagation uses COMCOT-LX, modified version of the COMCOT Cornnell University code. Maximum wave height (MWH) and tsunami energy direction are computed, for each tsunamigenic scenario for the north Atlantic coast of Morocco. Finally we selected the harbor of Casablanca for the production of inundation maps for Casablanca This research was funded by NEAREST and TRANSFER, 6FP-European Union. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AGUFM.U22A..02B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AGUFM.U22A..02B">Development of a GNSS-Enhanced Tsunami Early Warning System</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Bawden, G. W.; Melbourne, T. I.; Bock, Y.; Song, Y. T.; Komjathy, A. 2015-12-01 The past decade has witnessed a terrible loss of life and economic disruption caused by large earthquakes and resultant tsunamis impacting coastal communities and infrastructure across the Indo-Pacific region. NASA has funded the early development of a prototype real-time Global Navigation Satellite System (RT-GNSS) based rapid earthquake and tsunami early warning (GNSS-TEW) system that may be used to enhance seismic tsunami early warning systems for large earthquakes. This prototype GNSS-TEW system geodetically estimates fault parameters (earthquake magnitude, location, strike, dip, and slip magnitude/direction on a gridded fault plane both along strike and at depth) and tsunami source parameters (seafloor displacement, tsunami energy scale, and 3D tsunami initials) within minutes after the mainshock based on dynamic numerical inversions/regressions of the real-time measured displacements within a spatially distributed real-time GNSS network(s) spanning the epicentral region. It is also possible to measure fluctuations in the ionosphere's total electron content (TEC) in the RT-GNSS data caused by the pressure wave from the tsunami. This TEC approach can detect if a tsunami has been triggered by an earthquake, track its waves as they propagate through the oceanic basins, and provide upwards of 45 minutes early warning. These combined real-time geodetic approaches will very quickly address a number of important questions in the immediate minutes following a major earthquake: How big was the earthquake and what are its fault parameters? Could the earthquake have produced a tsunami and was a tsunami generated? </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009EGUGA..1113137N','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009EGUGA..1113137N">Earthquake and Tsunami: a movie and a book for seismic and tsunami risk reduction in Italy.</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Nostro, C.; Baroux, E.; Maramai, A.; Graziani, L.; Tertulliani, A.; Castellano, C.; Arcoraci, L.; Casale, P.; Ciaccio, M. G.; Frepoli, A. 2009-04-01 Italy is a country well known for the seismic and volcanic hazard. However, a similarly great hazard, although not well recognized, is posed by the occurrence of tsunami waves along the Italian coastline. This is testified by a rich catalogue and by field evidence of deposits left over by pre- and historical tsunamis, even in places today considered safe. This observation is of great importance since many of the areas affected by tsunamis in the past are today touristic places. The Italian tsunamis can be caused by different sources: 1- off-shore or near coast in-land earthquakes; 2- very large earthquakes on distant sources in the Mediterranean; 3- submarine volcanic explosion in the Tyrrhenian sea; 4- submarine landslides triggered by earthquakes and volcanic activity. The consequence of such a wide spectrum of sources is that an important part of the more than 7000 km long Italian coast line is exposed to the tsunami risk, and thousands of inhabitants (with numbers increasing during summer) live near hazardous coasts. The main historical tsunamis are the 1783 and 1908 events that hit Calabrian and Sicilian coasts. The recent tsunami is that caused by the 2002 Stromboli landslide. In order to reduce this risk and following the emotional impact of the December 2004 Sumatra earthquake and tsunami, we developed an outreach program consisting in talks given by scientists and in a movie and a book, both exploring the causes of the tsunami waves, how do they propagate in deep and shallow waters, and what are the effects on the coasts. Hints are also given on the most dangerous Italian coasts (as deduced by scientific studies), and how to behave in the case of a tsunami approaching the coast. These seminars are open to the general public, but special programs are developed with schools of all grades. In this talk we want to present the book and the movie used during the seminars and scientific expositions, that was realized from a previous 3D version originally </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AGUFMNH12A..09B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUFMNH12A..09B">Simulations and analysis of asteroid-generated tsunamis using the shallow water equations</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Berger, M. J.; LeVeque, R. J.; Weiss, R. 2016-12-01 We discuss tsunami propagation for asteroid-generated air bursts and water impacts. We present simulations for a range of conditions using the GeoClaw simulation software. Examples include meteors that span 5 to 250 MT of kinetic energy, and use bathymetry from the U.S. coastline. We also study radially symmetric one-dimensional equations to better explore the nature and decay rate of waves generated by air burst pressure disturbances traveling at the speed of sound in air, which is much greater than the gravity wave speed of the tsunami generated. One-dimensional simulations along a transect of bathymetry are also used to explore the resolution needed for the full two-dimensional simulations, which are much more expensive even with the use of adaptive mesh refinement due to the short wave lengths of these tsunamis. For this same reason, shallow water equations may be inadequate and we also discuss dispersive effects. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFMNH23A0255O','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFMNH23A0255O">Ionospheric detection of tsunami earthquakes: observation, modeling and ideas for future early warning</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Occhipinti, G.; Manta, F.; Rolland, L.; Watada, S.; Makela, J. J.; Hill, E.; Astafieva, E.; Lognonne, P. H. 2017-12-01 Detection of ionospheric anomalies following the Sumatra and Tohoku earthquakes (e.g., Occhipinti 2015) demonstrated that ionosphere is sensitive to earthquake and tsunami propagation: ground and oceanic vertical displacement induces acoustic-gravity waves propagating within the neutral atmosphere and detectable in the ionosphere. Observations supported by modelling proved that ionospheric anomalies related to tsunamis are deterministic and reproducible by numerical modeling via the ocean/neutral-atmosphere/ionosphere coupling mechanism (Occhipinti et al., 2008). To prove that the tsunami signature in the ionosphere is routinely detected we show here perturbations of total electron content (TEC) measured by GPS and following tsunamigenic earthquakes from 2004 to 2011 (Rolland et al. 2010, Occhipinti et al., 2013), nominally, Sumatra (26 December, 2004 and 12 September, 2007), Chile (14 November, 2007), Samoa (29 September, 2009) and the recent Tohoku-Oki (11 Mars, 2011). Based on the observations close to the epicenter, mainly performed by GPS networks located in Sumatra, Chile and Japan, we highlight the TEC perturbation observed within the first 8 min after the seismic rupture. This perturbation contains information about the ground displacement, as well as the consequent sea surface displacement resulting in the tsunami. In addition to GNSS-TEC observations close to the epicenter, new exciting measurements in the far-field were performed by airglow measurement in Hawaii show the propagation of the internal gravity waves induced by the Tohoku tsunami (Occhipinti et al., 2011). This revolutionary imaging technique is today supported by two new observations of moderate tsunamis: Queen Charlotte (M: 7.7, 27 October, 2013) and Chile (M: 8.2, 16 September 2015). We finally detail here our recent work (Manta et al., 2017) on the case of tsunami alert failure following the Mw7.8 Mentawai event (25 October, 2010), and its twin tsunami alert response following the Mw7 </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AGUFMNH21A3830K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AGUFMNH21A3830K">Influence of Earthquake Parameters on Tsunami Wave Height and Inundation</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Kulangara Madham Subrahmanian, D.; Sri Ganesh, J.; Venkata Ramana Murthy, M.; V, R. M. 2014-12-01 After Indian Ocean Tsunami (IOT) on 26th December, 2004, attempts are being made to assess the threat of tsunami originating from different sources for different parts of India. The Andaman - Sumatra trench is segmented by transcurrent faults and differences in the rate of subduction which is low in the north and increases southward. Therefore key board model with initial deformation calculated using different strike directions, slip rates, are used. This results in uncertainties in the earthquake parameters. This study is made to identify the location of origin of most destructive tsunami for Southeast coast of India and to infer the influence of the earthquake parameters in tsunami wave height travel time in deep ocean as well as in the shelf and inundation in the coast. Five tsunamigenic sources were considered in the Andaman - Sumatra trench taking into consideration the tectonic characters of the trench described by various authors and the modeling was carried out using TUNAMI N2 code. The model results were validated using the travel time and runup in the coastal areas and comparing the water elevation along Jason - 1's satellite track. The inundation results are compared from the field data. The assessment of the tsunami threat for the area south of Chennai city the metropolitan city of South India shows that a tsunami originating in Car Nicobar segment of the Andaman - Sumatra subduction zone can generate the most destructive tsunami. Sensitivity analysis in the modelling indicates that fault length influences the results significantly and the tsunami reaches early and with higher amplitude. Strike angle is also modifying the tsunami followed by amount of slip. </li> <li> <a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70026083','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70026083">Tsunamis generated by subaerial mass flows</a> <a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a> Walder, S.J.; Watts, P.; Sorensen, O.E.; Janssen, K. 2003-01-01 Tsunamis generated in lakes and reservoirs by subaerial mass flows pose distinctive problems for hazards assessment because the domain of interest is commonly the "near field," beyond the zone of complex splashing but close enough to the source that wave propagation effects are not predominant. Scaling analysis of the equations governing water wave propagation shows that near-field wave amplitude and wavelength should depend on certain measures of mass flow dynamics and volume. The scaling analysis motivates a successful collapse (in dimensionless space) of data from two distinct sets of experiments with solid block "wave makers." To first order, wave amplitude/water depth is a simple function of the ratio of dimensionless wave maker travel time to dimensionless wave maker volume per unit width. Wave amplitude data from previous laboratory investigations with both rigid and deformable wave makers follow the same trend in dimensionless parameter space as our own data. The characteristic wavelength/water depth for all our experiments is simply proportional to dimensionless wave maker travel time, which is itself given approximately by a simple function of wave maker length/water depth. Wave maker shape and rigidity do not otherwise influence wave features. Application of the amplitude scaling relation to several historical events yields "predicted" near-field wave amplitudes in reasonable agreement with measurements and observations. Together, the scaling relations for near-field amplitude, wavelength, and submerged travel time provide key inputs necessary for computational wave propagation and hazards assessment. </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_6");'>6</a></li> <li><a href="#" onclick='return showDiv("page_7");'>7</a></li> <li class="active">8</li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> </div> <div id="page_9" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_7");'>7</a></li> <li><a href="#" onclick='return showDiv("page_8");'>8</a></li> <li class="active">9</li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="161"> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016EGUGA..1811036L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016EGUGA..1811036L">Implementation of a Global Navigation Satellite System (GNSS) Augmentation to Tsunami Early Warning Systems</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> LaBrecque, John 2016-04-01 The Global Geodetic Observing System has issued a Call for Participation to research scientists, geodetic research groups and national agencies in support of the implementation of the IUGG recommendation for a Global Navigation Satellite System (GNSS) Augmentation to Tsunami Early Warning Systems. The call seeks to establish a working group to be a catalyst and motivating force for the definition of requirements, identification of resources, and for the encouragement of international cooperation in the establishment, advancement, and utilization of GNSS for Tsunami Early Warning. During the past fifteen years the populations of the Indo-Pacific region experienced a series of mega-thrust earthquakes followed by devastating tsunamis that claimed nearly 300,000 lives. The future resiliency of the region will depend upon improvements to infrastructure and emergency response that will require very significant investments from the Indo-Pacific economies. The estimation of earthquake moment magnitude, source mechanism and the distribution of crustal deformation are critical to rapid tsunami warning. Geodetic research groups have demonstrated the use of GNSS data to estimate earthquake moment magnitude, source mechanism and the distribution of crustal deformation sufficient for the accurate and timely prediction of tsunamis generated by mega-thrust earthquakes. GNSS data have also been used to measure the formation and propagation of tsunamis via ionospheric disturbances acoustically coupled to the propagating surface waves; thereby providing a new technique to track tsunami propagation across ocean basins, opening the way for improving tsunami propagation models, and providing accurate warning to communities in the far field. These two new advancements can deliver timely and accurate tsunami warnings to coastal communities in the near and far field of mega-thrust earthquakes. This presentation will present the justification for and the details of the GGOS Call for </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017EGUGA..1919608B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017EGUGA..1919608B">A Benchmarking setup for Coupled Earthquake Cycle - Dynamic Rupture - Tsunami Simulations</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Behrens, Joern; Bader, Michael; van Dinther, Ylona; Gabriel, Alice-Agnes; Madden, Elizabeth H.; Ulrich, Thomas; Uphoff, Carsten; Vater, Stefan; Wollherr, Stephanie; van Zelst, Iris 2017-04-01 We developed a simulation framework for coupled physics-based earthquake rupture generation with tsunami propagation and inundation on a simplified subduction zone system for the project "Advanced Simulation of Coupled Earthquake and Tsunami Events" (ASCETE, funded by the Volkswagen Foundation). Here, we present a benchmarking setup that can be used for complex rupture models. The workflow begins with a 2D seismo-thermo-mechanical earthquake cycle model representing long term deformation along a planar, shallowly dipping subduction zone interface. Slip instabilities that approximate earthquakes arise spontaneously along the subduction zone interface in this model. The absolute stress field and material properties for a single slip event are used as initial conditions for a dynamic earthquake rupture model.The rupture simulation is performed with SeisSol, which uses an ADER discontinuous Galerkin discretization scheme with an unstructured tetrahedral mesh. The seafloor displacements resulting from this rupture are transferred to the tsunami model with a simple coastal run-up profile. An adaptive mesh discretizing the shallow water equations with a Runge-Kutta discontinuous Galerkin (RKDG) scheme subsequently allows for an accurate and efficient representation of the tsunami evolution and inundation at the coast. This workflow allows for evaluation of how the rupture behavior affects the hydrodynamic wave propagation and coastal inundation. We present coupled results for differing earthquake scenarios. Examples include megathrust only ruptures versus ruptures with splay fault branching off the megathrust near the surface. Coupling to the tsunami simulation component is performed either dynamically (time dependent) or statically, resulting in differing tsunami wave and inundation behavior. The simplified topographical setup allows for systematic parameter studies and reproducible physical studies. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFMNH51C..04R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFMNH51C..04R">Atmospheric resonances of the Rayleigh and tsunami normal modes and its sensitivity to local time and geographical location.</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Rakoto, V.; Astafyeva, E.; Lognonne, P. H. 2017-12-01 It is known that natural hazard events, such as earthquakes, tsunamis, volcano eruptions, etc. can generate atmospheric/ionospheric perturbations. During earthquakes, vertical displacements of the ground or of the ocean floor generate acoustic-gravity waves that further propagate upward in the upper atmosphere and ionosphere. In turn, tsunamis propagating in the open sea, generate gravity waves which propagate obliquely and reach the ionosphere in 45-60 min. The properties of the atmospheric "channel" in the vertical and oblique propagation depend on a variety of factors such as solar and geomagnetic conditions, latitude, local time, season, and their influence on propagation and properties of co-seismic and co-tsunamic perturbations is not well understood yet. In this work, we use present a detailed study of the coupling efficiency between solid earth, ocean and atmosphere. For this purpose, we use the normal mode technique extended to the whole solid Earth-ocean-atmosphere system. In our study, we focus on the Rayleigh modes (solid modes) and tsunami modes (oceanic modes). As the normal modes amplitude are also depending on the spatial and temporal variation of the structure of the atmosphere, we also performed a sensitivity study location of the normal modes amplitude with local time and geographical position. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014EGUGA..16..752K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014EGUGA..16..752K">Display of historical and hypothetical tsunami on the coast of Sakhalin Island</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Kostenko, Irina; Zaytsev, Andrey; Kurkin, Andrey; Yalciner, Ahmet 2014-05-01 Tsunami waves achieve the coast of the Sakhalin Island and their sources are located in the Japan Sea, in the Okhotsk Sea, in Kuril Islands region and in the Pacific Ocean. Study of tsunami generation characteristics and its propagation allows studying display of the tsunami on the various parts of the island coast. For this purpose the series of computational experiments of some historical tsunamis was carried out. Their sources located in Japan Sea and Kuril Islands region. The simulation results are compared with the observations. Analysis of all recorded historical tsunami on coast of Sakhalin Island was done. To identify the possible display of the tsunami on the coast of Sakhalin Island the series of computational experiments of hypothetical tsunamis was carried out. Their sources located in the Japan Sea and in the Okhotsk Sea. There were used hydrodynamic sources. There were used different parameters of sources (length, width, height, raising and lowering of sea level), which correspond to earthquakes of various magnitudes. The analysis of the results was carried out. Pictures of the distribution of maximum amplitudes from each tsunami were done. Areas of Okhotsk Sea, Japan Sea and offshore strip of Sakhalin Island with maximum tsunami amplitudes were defined. Graphs of the distribution of maximum tsunami wave heights along the coast of the Sakhalin Island were plotted. Based on shallow-water equation tsunami numerical code NAMI DANCE was used for numerical simulations. This work was supported by ASTARTE project. </li> <li> <a target="_blank" onclick="trackOutboundLink('https://images.nasa.gov/#/details-PIA07219.html','SCIGOVIMAGE-NASA'); return false;" href="https://images.nasa.gov/#/details-PIA07219.html">NASA/French Satellite Data Reveal New Details of Tsunami</a> <a target="_blank" href="https://images.nasa.gov/">NASA Image and Video Library</a> 2005-01-12 Displayed in blue color is the height of sea surface (shown in blue) measured by the Jason satellite two hours after the initial magnitude 9 earthquake hit the region (shown in red) southwest of Sumatra on December 26, 2004. The data were taken by a radar altimeter onboard the satellite along a track traversing the Indian Ocean when the tsunami waves had just filled the entire Bay of Bengal (see the model simulation inset image). The data shown are the changes of sea surface height from previous observations made along the same track 20-30 days before the earthquake, reflecting the signals of the tsunami waves. The maximum height of the leading wave crest was about 50 cm (or 1.6 ft), followed by a trough of sea surface depression of 40 cm. The directions of wave propagation along the satellite track are shown by the blue arrows. http://photojournal.jpl.nasa.gov/catalog/PIA07219 </li> <li> <a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20170000319','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20170000319">Tsunami Generation from Asteroid Airburst and Ocean Impact and Van Dorn Effect</a> <a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a> Robertson, Darrel 2016-01-01 Airburst - In the simulations explored energy from the airburst couples very weakly with the water making tsunami dangerous over a shorter distance than the blast for asteroid sizes up to the maximum expected size that will still airburst (approx.250MT). Future areas of investigation: - Low entry angle airbursts create more cylindrical blasts and might couple more efficiently - Bursts very close to the ground will increase coupling - Inclusion of thermosphere (>80km altitude) may show some plume collapse effects over a large area although with much less pressure center dot Ocean Impact - Asteroid creates large cavity in ocean. Cavity backfills creating central jet. Oscillation between the cavity and jet sends out tsunami wave packet. - For deep ocean impact waves are deep water waves (Phase speed = 2x Group speed) - If the tsunami propagation and inundation calculations are correct for the small (<250MT) asteroids in these simulations where they impact deep ocean basins, the resulting tsunami is not a significant hazard unless particularly close to vulnerable communities. Future work: - Shallow ocean impact. - Effect of continental shelf and beach profiles - Tsunami vs. blast damage radii for impacts close to populated areas - Larger asteroids below presumed threshold of global effects (Ø200 - 800m). </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014JGRB..119.5574Y','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014JGRB..119.5574Y">Rupture process of the 2010 Mw 7.8 Mentawai tsunami earthquake from joint inversion of near-field hr-GPS and teleseismic body wave recordings constrained by tsunami observations</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Yue, Han; Lay, Thorne; Rivera, Luis; Bai, Yefei; Yamazaki, Yoshiki; Cheung, Kwok Fai; Hill, Emma M.; Sieh, Kerry; Kongko, Widjo; Muhari, Abdul 2014-07-01 The 25 October 2010 Mentawai tsunami earthquake (Mw 7.8) ruptured the shallow portion of the Sunda megathrust seaward of the Mentawai Islands, offshore of Sumatra, Indonesia, generating a strong tsunami that took 509 lives. The rupture zone was updip of those of the 12 September 2007 Mw 8.5 and 7.9 underthrusting earthquakes. High-rate (1 s sampling) GPS instruments of the Sumatra GPS Array network deployed on the Mentawai Islands and Sumatra mainland recorded time-varying and static ground displacements at epicentral distances from 49 to 322 km. Azimuthally distributed tsunami recordings from two deepwater sensors and two tide gauges that have local high-resolution bathymetric information provide additional constraints on the source process. Finite-fault rupture models, obtained by joint inversion of the high-rate (hr)-GPS time series and numerous teleseismic broadband P and S wave seismograms together with iterative forward modeling of the tsunami recordings, indicate rupture propagation ~50 km up dip and ~100 km northwest along strike from the hypocenter, with a rupture velocity of ~1.8 km/s. Subregions with large slip extend from 7 to 10 km depth ~80 km northwest from the hypocenter with a maximum slip of 8 m and from ~5 km depth to beneath thin horizontal sedimentary layers beyond the prism deformation front for ~100 km along strike, with a localized region having >15 m of slip. The seismic moment is 7.2 × 1020 N m. The rupture model indicates that local heterogeneities in the shallow megathrust can accumulate strain that allows some regions near the toe of accretionary prisms to fail in tsunami earthquakes. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017ISPAr42W7..461D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017ISPAr42W7..461D">Tsunami Risk Assessment Modelling in Chabahar Port, Iran</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Delavar, M. R.; Mohammadi, H.; Sharifi, M. A.; Pirooz, M. D. 2017-09-01 The well-known historical tsunami in the Makran Subduction Zone (MSZ) region was generated by the earthquake of November 28, 1945 in Makran Coast in the North of Oman Sea. This destructive tsunami killed over 4,000 people in Southern Pakistan and India, caused great loss of life and devastation along the coasts of Western India, Iran and Oman. According to the report of "Remembering the 1945 Makran Tsunami", compiled by the Intergovernmental Oceanographic Commission (UNESCO/IOC), the maximum inundation of Chabahar port was 367 m toward the dry land, which had a height of 3.6 meters from the sea level. In addition, the maximum amount of inundation at Pasni (Pakistan) reached to 3 km from the coastline. For the two beaches of Gujarat (India) and Oman the maximum run-up height was 3 m from the sea level. In this paper, we first use Makran 1945 seismic parameters to simulate the tsunami in generation, propagation and inundation phases. The effect of tsunami on Chabahar port is simulated using the ComMIT model which is based on the Method of Splitting Tsunami (MOST). In this process the results are compared with the documented eyewitnesses and some reports from researchers for calibration and validation of the result. Next we have used the model to perform risk assessment for Chabahar port in the south of Iran with the worst case scenario of the tsunami. The simulated results showed that the tsunami waves will reach Chabahar coastline 11 minutes after generation and 9 minutes later, over 9.4 Km2 of the dry land will be flooded with maximum wave amplitude reaching up to 30 meters. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015EGUGA..17.4219G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015EGUGA..17.4219G">Ionospheric manifestations of earthquakes and tsunamis in a dynamic atmosphere</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Godin, Oleg A.; Zabotin, Nikolay A.; Zabotina, Liudmila 2015-04-01 Observations of the ionosphere provide a new, promising modality for characterizing large-scale physical processes that occur on land and in the ocean. There is a large and rapidly growing body of evidence that a number of natural hazards, including large earthquakes, strong tsunamis, and powerful tornadoes, have pronounced ionospheric manifestations, which are reliably detected by ground-based and satellite-borne instruments. As the focus shifts from detecting the ionospheric features associated with the natural hazards to characterizing the hazards for the purposes of improving early warning systems and contributing to disaster recovery, it becomes imperative to relate quantitatively characteristics of the observed ionospheric disturbances and the underlying natural hazard. The relation between perturbations at the ground level and their ionospheric manifestations is strongly affected by parameters of the intervening atmosphere. In this paper, we employ the ray theory to model propagation of acoustic-gravity waves in three-dimensionally inhomogeneous atmosphere. Huygens' wavefront-tracing and Hamiltonian ray-tracing algorithms are used to simulate propagation of body waves from an earthquake hypocenter through the earth's crust and ocean to the upper atmosphere. We quantify the influence of temperature stratification and winds, including their seasonal variability, and air viscosity and thermal conductivity on the geometry and amplitude of ionospheric disturbances that are generated by seismic surface waves and tsunamis. Modeling results are verified by comparing observations of the velocity fluctuations at altitudes of 150-160 km by a coastal Dynasonde HF radar system with theoretical predictions of ionospheric manifestations of background infragravity waves in the ocean. Dynasonde radar systems are shown to be a promising means for monitoring acoustic-gravity wave activity and observing ionospheric perturbations due to earthquakes and tsunamis. We will discuss </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016EGUGA..18.9727M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016EGUGA..18.9727M">How can coastal parks contain the destructive impact of a tsunami? A numerical approach to the understanding of tsunami-triggered waves in the presence of coastal hills</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Marras, Simone; Suckale, Jenny; Lunghino, Brent; Giraldo, Francis X.; Constantinescu, Emil 2016-04-01 From the now common idea that vegetated shores may reduce the power of a destructive storm surge, an increasing number of coastal communities around the world are extending this thinking to the design of coastal parks as a way to limit the impact of a tsunami. Tsunamis and storm surges are significantly different in nature and behavior, and it is implausible that vegetation alone could act as a tsunami mitigation tool. A more comprehensive approach relies on the installation of vegetated, scattered mitigation hills in front of the shore to deviate the incoming tsunami wave instead. The analysis of how natural obstacles affect non-linear tsunami waves is still very limited and consists mostly of one-dimensional studies (e.g., [1, 2]). To that end, this work aims to extend the analysis of the interaction of waves of different shapes (solitary wave, N-wave), sizes (amplitude and wave length), and configurations with large obstacles to two-dimensional flows. The following metrics are used for a quantification of the results: 1) tsunami run-up and run-down and 2) a measure of channelization (via the flow kinetic energy and discharge). First, preliminary results show that the configuration of the obstacles is consequential as long as the amplitude of the incoming wave is large enough relative to the obstacles. In second instance, we also observed that the channelization of the flow between two neighboring obstacles may not be greatly affected solely by the distance between obstacles, but must be analyzed in relationship to the initial wave/wave train. This study is based on the numerical solution of the viscous shallow water equations via high order discontinuous finite elements method (DG) using a quadrilateral version of the model described in [3] and with fully implicit time integration [4]. Large and relatively massive hills appear to be a better solution than any offshore concrete walls, which have shown to possibly enhance the tsunami catastrophic power rather than </li> <li> <a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20060044038&hterms=tsunami&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Dtsunami','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20060044038&hterms=tsunami&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Dtsunami">The 26 December 2004 tsunami source estimated from satellite radar altimetry and seismic waves</a> <a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a> Song, Tony Y.; Ji, Chen; Fu, L. -L.; Zlotnicki, Victor; Shum, C. K.; Yi, Yuchan; Hjorleifsdottir, Vala 2005-01-01 The 26 December 2004 Indian Ocean tsunami was the first earthquake tsunami of its magnitude to occur since the advent of both digital seismometry and satellite radar altimetry. Both have independently recorded the event from different physical aspects. The seismic data has then been used to estimate the earthquake fault parameters, and a three-dimensional ocean-general-circulation-model (OGCM) coupled with the fault information has been used to simulate the satellite-observed tsunami waves. Here we show that these two datasets consistently provide the tsunami source using independent methodologies of seismic waveform inversion and ocean modeling. Cross-examining the two independent results confirms that the slip function is the most important condition controlling the tsunami strength, while the geometry and the rupture velocity of the tectonic plane determine the spatial patterns of the tsunami. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014PApGe.171.3351F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014PApGe.171.3351F">Marshall Islands Fringing Reef and Atoll Lagoon Observations of the Tohoku Tsunami</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Ford, Murray; Becker, Janet M.; Merrifield, Mark A.; Song, Y. Tony 2014-12-01 The magnitude 9.0 Tohoku earthquake on 11 March 2011 generated a tsunami which caused significant impacts throughout the Pacific Ocean. A description of the tsunami within the lagoons and on the surrounding fringing reefs of two mid-ocean atoll islands is presented using bottom pressure observations from the Majuro and Kwajalein atolls in the Marshall Islands, supplemented by tide gauge data in the lagoons and by numerical model simulations in the deep ocean. Although the initial wave arrival was not captured by the pressure sensors, subsequent oscillations on the reef face resemble the deep ocean tsunami signal simulated by two numerical models, suggesting that the tsunami amplitudes over the atoll outer reefs are similar to that in deep water. In contrast, tsunami oscillations in the lagoon are more energetic and long lasting than observed on the reefs or modelled in the deep ocean. The tsunami energy in the Majuro lagoon exhibits persistent peaks in the 30 and 60 min period bands that suggest the excitation of closed and open basin normal modes, while energy in the Kwajalein lagoon spans a broader range of frequencies with weaker, multiple peaks than observed at Majuro, which may be associated with the tsunami behavior within the more irregular geometry of the Kwajalein lagoon. The propagation of the tsunami across the reef flats is shown to be tidally dependent, with amplitudes increasing/decreasing shoreward at high/low tide. The impact of the tsunami on the Marshall Islands was reduced due to the coincidence of peak wave amplitudes with low tide; however, the observed wave amplitudes, particularly in the atoll lagoon, would have led to inundation at different tidal phases. </li> <li> <a target="_blank" onclick="trackOutboundLink('https://medlineplus.gov/tsunamis.html','NIH-MEDLINEPLUS'); return false;" href="https://medlineplus.gov/tsunamis.html">Tsunamis</a> <a target="_blank" href="http://medlineplus.gov/">MedlinePlus</a> A tsunami is a series of huge ocean waves created by an underwater disturbance. Causes include earthquakes, landslides, volcanic ... space that strike the surface of Earth. A tsunami can move hundreds of miles per hour in ... </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018PApGe.175.1405C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018PApGe.175.1405C">A Collaborative Effort Between Caribbean States for Tsunami Numerical Modeling: Case Study CaribeWave15</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Chacón-Barrantes, Silvia; López-Venegas, Alberto; Sánchez-Escobar, Rónald; Luque-Vergara, Néstor 2018-04-01 Historical records have shown that tsunami have affected the Caribbean region in the past. However infrequent, recent studies have demonstrated that they pose a latent hazard for countries within this basin. The Hazard Assessment Working Group of the ICG/CARIBE-EWS (Intergovernmental Coordination Group of the Early Warning System for Tsunamis and Other Coastal Threats for the Caribbean Sea and Adjacent Regions) of IOC/UNESCO has a modeling subgroup, which seeks to develop a modeling platform to assess the effects of possible tsunami sources within the basin. The CaribeWave tsunami exercise is carried out annually in the Caribbean region to increase awareness and test tsunami preparedness of countries within the basin. In this study we present results of tsunami inundation using the CaribeWave15 exercise scenario for four selected locations within the Caribbean basin (Colombia, Costa Rica, Panamá and Puerto Rico), performed by tsunami modeling researchers from those selected countries. The purpose of this study was to provide the states with additional results for the exercise. The results obtained here were compared to co-seismic deformation and tsunami heights within the basin (energy plots) provided for the exercise to assess the performance of the decision support tools distributed by PTWC (Pacific Tsunami Warning Center), the tsunami service provider for the Caribbean basin. However, comparison of coastal tsunami heights was not possible, due to inconsistencies between the provided fault parameters and the modeling results within the provided exercise products. Still, the modeling performed here allowed to analyze tsunami characteristics at the mentioned states from sources within the North Panamá Deformed Belt. The occurrence of a tsunami in the Caribbean may affect several countries because a great variety of them share coastal zones in this basin. Therefore, collaborative efforts similar to the one presented in this study, particularly between neighboring </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017PApGe.tmp..406C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017PApGe.tmp..406C">A Collaborative Effort Between Caribbean States for Tsunami Numerical Modeling: Case Study CaribeWave15</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Chacón-Barrantes, Silvia; López-Venegas, Alberto; Sánchez-Escobar, Rónald; Luque-Vergara, Néstor 2017-10-01 Historical records have shown that tsunami have affected the Caribbean region in the past. However infrequent, recent studies have demonstrated that they pose a latent hazard for countries within this basin. The Hazard Assessment Working Group of the ICG/CARIBE-EWS (Intergovernmental Coordination Group of the Early Warning System for Tsunamis and Other Coastal Threats for the Caribbean Sea and Adjacent Regions) of IOC/UNESCO has a modeling subgroup, which seeks to develop a modeling platform to assess the effects of possible tsunami sources within the basin. The CaribeWave tsunami exercise is carried out annually in the Caribbean region to increase awareness and test tsunami preparedness of countries within the basin. In this study we present results of tsunami inundation using the CaribeWave15 exercise scenario for four selected locations within the Caribbean basin (Colombia, Costa Rica, Panamá and Puerto Rico), performed by tsunami modeling researchers from those selected countries. The purpose of this study was to provide the states with additional results for the exercise. The results obtained here were compared to co-seismic deformation and tsunami heights within the basin (energy plots) provided for the exercise to assess the performance of the decision support tools distributed by PTWC (Pacific Tsunami Warning Center), the tsunami service provider for the Caribbean basin. However, comparison of coastal tsunami heights was not possible, due to inconsistencies between the provided fault parameters and the modeling results within the provided exercise products. Still, the modeling performed here allowed to analyze tsunami characteristics at the mentioned states from sources within the North Panamá Deformed Belt. The occurrence of a tsunami in the Caribbean may affect several countries because a great variety of them share coastal zones in this basin. Therefore, collaborative efforts similar to the one presented in this study, particularly between neighboring </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AGUFMNH12A..08G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AGUFMNH12A..08G">Development of algorithms for tsunami detection by High Frequency Radar based on modeling tsunami case studies in the Mediterranean Sea</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Grilli, S. T.; Guérin, C. A.; Grosdidier, S. 2014-12-01 Where coastal tsunami hazard is governed by near-field sources, Submarine Mass Failures (SMFs) or earthquakes, tsunami propagation times may be too small for a detection based on deep or shallow water buoys. To offer sufficient warning time, it has been proposed by others to implement early warning systems relying on High Frequency Radar (HFR) remote sensing, that has a dense spatial coverage far offshore. A new HFR, referred to as STRADIVARIUS, is being deployed by Diginext Inc. (in Fall 2014), to cover the "Golfe du Lion" (GDL) in the Western Mediterranean Sea. This radar uses a proprietary phase coding technology that allows detection up to 300 km, in a bistatic configuration (for which radar and antennas are separated by about 100 km). Although the primary purpose of the radar is vessel detection in relation to homeland security, the 4.5 MHz HFR will provide a strong backscattered signal for ocean surface waves at the so-called Bragg frequency (here, wavelength of 30 m). The current caused by an arriving tsunami will shift the Bragg frequency, by a value proportional to the current magnitude (projected on the local radar ray direction), which can be easily obtained from the Doppler spectrum of the HFR signal. Using state of the art tsunami generation and propagation models, we modeled tsunami case studies in the western Mediterranean basin (both seismic and SMFs) and simulated the HFR backscattered signal that would be detected for the entire GDL and beyond. Based on simulated HFR signal, we developed two types of tsunami detection algorithms: (i) one based on standard Doppler spectra, for which we found that to be detectable within the environmental and background current noises, the Doppler shift requires tsunami currents to be at least 10-15 cm/s, which typically only occurs on the continental shelf in fairly shallow water; (ii) to allow earlier detection, a second algorithm computes correlations of the HFR signals at two distant locations, shifted in time </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015EGUGA..17.6564G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015EGUGA..17.6564G">Development of algorithms for tsunami detection by High Frequency Radar based on modeling tsunami case studies in the Mediterranean Sea</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Grilli, Stéphan; Guérin, Charles-Antoine; Grosdidier, Samuel 2015-04-01 Where coastal tsunami hazard is governed by near-field sources, Submarine Mass Failures (SMFs) or earthquakes, tsunami propagation times may be too small for a detection based on deep or shallow water buoys. To offer sufficient warning time, it has been proposed by others to implement early warning systems relying on High Frequency Surface Wave Radar (HFSWR) remote sensing, that has a dense spatial coverage far offshore. A new HFSWR, referred to as STRADIVARIUS, has been recently deployed by Diginext Inc. to cover the "Golfe du Lion" (GDL) in the Western Mediterranean Sea. This radar, which operates at 4.5 MHz, uses a proprietary phase coding technology that allows detection up to 300 km in a bistatic configuration (with a baseline of about 100 km). Although the primary purpose of the radar is vessel detection in relation to homeland security, it can also be used for ocean current monitoring. The current caused by an arriving tsunami will shift the Bragg frequency by a value proportional to a component of its velocity, which can be easily obtained from the Doppler spectrum of the HFSWR signal. Using state of the art tsunami generation and propagation models, we modeled tsunami case studies in the western Mediterranean basin (both seismic and SMFs) and simulated the HFSWR backscattered signal that would be detected for the entire GDL and beyond. Based on simulated HFSWR signal, we developed two types of tsunami detection algorithms: (i) one based on standard Doppler spectra, for which we found that to be detectable within the environmental and background current noises, the Doppler shift requires tsunami currents to be at least 10-15 cm/s, which typically only occurs on the continental shelf in fairly shallow water; (ii) to allow earlier detection, a second algorithm computes correlations of the HFSWR signals at two distant locations, shifted in time by the tsunami propagation time between these locations (easily computed based on bathymetry). We found that this </li> <li> <a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/16123264','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/16123264">The global reach of the 26 December 2004 Sumatra tsunami.</a> <a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a> Titov, Vasily; Rabinovich, Alexander B; Mofjeld, Harold O; Thomson, Richard E; González, Frank I 2005-09-23 Numerical model simulations, combined with tide-gauge and satellite altimetry data, reveal that wave amplitudes, directionality, and global propagation patterns of the 26 December 2004 Sumatra tsunami were primarily determined by the orientation and intensity of the offshore seismic line source and subsequently by the trapping effect of mid-ocean ridge topographic waveguides. </li> <li> <a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4346147','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4346147">Method of calculating tsunami travel times in the Andaman Sea region</a> <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a> Visuthismajarn, Parichart; Tanavud, Charlchai; Robson, Mark G. 2014-01-01 A new model to calculate tsunami travel times in the Andaman Sea region has been developed. The model specifically provides more accurate travel time estimates for tsunamis propagating to Patong Beach on the west coast of Phuket, Thailand. More generally, the model provides better understanding of the influence of the accuracy and resolution of bathymetry data on the accuracy of travel time calculations. The dynamic model is based on solitary wave theory, and a lookup function is used to perform bilinear interpolation of bathymetry along the ray trajectory. The model was calibrated and verified using data from an echosounder record, tsunami photographs, satellite altimetry records, and eyewitness accounts of the tsunami on 26 December 2004. Time differences for 12 representative targets in the Andaman Sea and the Indian Ocean regions were calculated. The model demonstrated satisfactory time differences (<2 min/h), despite the use of low resolution bathymetry (ETOPO2v2). To improve accuracy, the dynamics of wave elevation and a velocity correction term must be considered, particularly for calculations in the nearshore region. PMID:25741129 </li> <li> <a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25741129','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25741129">Method of calculating tsunami travel times in the Andaman Sea region.</a> <a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a> Kietpawpan, Monte; Visuthismajarn, Parichart; Tanavud, Charlchai; Robson, Mark G 2008-07-01 A new model to calculate tsunami travel times in the Andaman Sea region has been developed. The model specifically provides more accurate travel time estimates for tsunamis propagating to Patong Beach on the west coast of Phuket, Thailand. More generally, the model provides better understanding of the influence of the accuracy and resolution of bathymetry data on the accuracy of travel time calculations. The dynamic model is based on solitary wave theory, and a lookup function is used to perform bilinear interpolation of bathymetry along the ray trajectory. The model was calibrated and verified using data from an echosounder record, tsunami photographs, satellite altimetry records, and eyewitness accounts of the tsunami on 26 December 2004. Time differences for 12 representative targets in the Andaman Sea and the Indian Ocean regions were calculated. The model demonstrated satisfactory time differences (<2 min/h), despite the use of low resolution bathymetry (ETOPO2v2). To improve accuracy, the dynamics of wave elevation and a velocity correction term must be considered, particularly for calculations in the nearshore region. </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_7");'>7</a></li> <li><a href="#" onclick='return showDiv("page_8");'>8</a></li> <li class="active">9</li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> </div> <div id="page_10" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_8");'>8</a></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li class="active">10</li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="181"> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AGUFMNH51A1923R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUFMNH51A1923R">Contribution of ionospheric monitoring to tsunami warning: results from a benchmark exercise</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Rolland, L.; Makela, J. J.; Drob, D. P.; Occhipinti, G.; Lognonne, P. H.; Kherani, E. A.; Sladen, A.; Rakoto, V.; Grawe, M.; Meng, X.; Komjathy, A.; Liu, T. J. Y.; Astafyeva, E.; Coisson, P.; Budzien, S. A. 2016-12-01 Deep ocean pressure sensors have proven very effective to quantify tsunami waves in real-time. Yet, the cost of these sensors and maintenance strongly limit the extensive deployment of dense networks. Thus a complete observation of the tsunami wave-field is not possible so far. In the last decade, imprints of moderate to large transpacific tsunami wave-fields have been registered in the ionosphere through the atmospheric internal gravity wave coupled with the tsunami during its propagation. Those ionospheric observations could provide a an additional description of the phenomenon with a high spatial coverage. Ionospheric observations have been supported by numerical modeling of the ocean-atmosphere-ionosphere coupling, developed by different groups. We present here the first results of a cross-validation exercise aimed at testing various forward simulation techniques. In particular, we compare different approaches for modeling tsunami-induced gravity waves including a pseudo-spectral method, finite difference schemes, a fully coupled normal modes modeling approach, a Fourier-Laplace compressible ray-tracing solution, and a self-consistent, three-dimensional physics-based wave perturbation (WP) model based on the augmented Global Thermosphere-Ionosphere Model (WP-GITM). These models and other existing models use either a realistic sea-surface motion input model or a simple analytic model. We discuss the advantages and drawbacks of the different methods and setup common inputs to the models so that meaningful comparisons of model outputs can be made to higlight physical conclusions and understanding. Nominally, we highlight how the different models reproduce or disagree for two study cases: the ionospheric observations related to the 2012 Mw7.7 Haida Gwaii, Canada, and 2015 Mw8.3 Illapel, Chile, events. Ultimately, we explore the possibility of computing a transfer function in order to convert ionospheric perturbations directly into tsunami height estimates. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016JGRC..121.7701B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016JGRC..121.7701B">Tsunami generation and associated waves in the water column and seabed due to an asymmetric earthquake motion within an anisotropic substratum</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Bagheri, Amirhossein; Greenhalgh, Stewart; Khojasteh, Ali; Rahimian, Mohammad; Attarnejad, Reza 2016-10-01 In this paper, closed-form integral expressions are derived to describe how surface gravity waves (tsunamis) are generated when general asymmetric ground displacement (due to earthquake rupturing), involving both horizontal and vertical components of motion, occurs at arbitrary depth within the interior of an anisotropic subsea solid beneath the ocean. In addition, we compute the resultant hydrodynamic pressure within the seawater and the elastic wavefield within the seabed at any position. The method of potential functions and an integral transform approach, accompanied by a special contour integration scheme, are adopted to handle the equations of motion and produce the numerical results. The formulation accounts for any number of possible acoustic-gravity modes and is valid for both shallow and deep water situations as well as for any focal depth of the earthquake source. Phase and group velocity dispersion curves are developed for surface gravity (tsunami mode), acoustic-gravity, Rayleigh, and Scholte waves. Several asymptotic cases which arise from the general analysis are discussed and compared to existing solutions. The role of effective parameters such as hypocenter location and frequency of excitation is examined and illustrated through several figures which show the propagation pattern in the vertical and horizontal directions. Attention is directed to the unexpected contribution from the horizontal ground motion. The results have important application in several fields such as tsunami hazard prediction, marine seismology, and offshore and coastal engineering. In a companion paper, we examine the effect of ocean stratification on the appearance and character of internal and surface gravity waves. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017JGRC..122.7992R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017JGRC..122.7992R">The 2004 Sumatra tsunami in the Southeastern Pacific Ocean: New Global Insight from Observations and Modeling</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Rabinovich, A. B.; Titov, V. V.; Moore, C. W.; Eblé, M. C. 2017-10-01 The 2004 Sumatra tsunami was an unprecedented global disaster measured throughout the world oceans. The present study focused on a region of the southeastern Pacific Ocean where the "westward" circumferentially propagating tsunami branch converged with the "eastward" branch, based on data from fortuitously placed Chilean DART 32401 and tide gauges along the coast of South America. By comparison of the tsunami and background spectra, we suppressed the influence of topography and reconstructed coastal "spectral ratios" that were in close agreement with a ratio at DART 32401 and spectral ratios in other oceans. Findings indicate that even remote tsunami records carry spectral source signatures ("birth-marks"). The 2004 tsunami waves were found to occupy the broad frequency band of 0.25-10 cph with the prominent ratio peak at period of 40 min related to the southern fast-slip source domain. This rupture "hot-spot" of ˜350 km was responsible for the global impact of the 2004 tsunami. Data from DART 32401 provided validation of model results: the simulated maximum tsunami wave height of 2.25 cm was a conservative approximation to the measured height of 2.05 cm; the computed tsunami travel time of 25 h 35 min to DART 32401, although 20 min earlier than the actual travel time, provided a favorable result in comparison with 24 h 25 min estimated from classical kinematic theory. The numerical simulations consistently reproduced the wave height changes observed along the coast of South America, including local amplification of tsunami waves at the northern stations of Arica (72 cm) and Callao (67 cm). </li> <li> <a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/24399356','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/24399356">Tsunami: ocean dynamo generator.</a> <a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a> Sugioka, Hiroko; Hamano, Yozo; Baba, Kiyoshi; Kasaya, Takafumi; Tada, Noriko; Suetsugu, Daisuke 2014-01-08 Secondary magnetic fields are induced by the flow of electrically conducting seawater through the Earth's primary magnetic field ('ocean dynamo effect'), and hence it has long been speculated that tsunami flows should produce measurable magnetic field perturbations, although the signal-to-noise ratio would be small because of the influence of the solar magnetic fields. Here, we report on the detection of deep-seafloor electromagnetic perturbations of 10-micron-order induced by a tsunami, which propagated through a seafloor electromagnetometer array network. The observed data extracted tsunami characteristics, including the direction and velocity of propagation as well as sea-level change, first to verify the induction theory. Presently, offshore observation systems for the early forecasting of tsunami are based on the sea-level measurement by seafloor pressure gauges. In terms of tsunami forecasting accuracy, the integration of vectored electromagnetic measurements into existing scalar observation systems would represent a substantial improvement in the performance of tsunami early-warning systems. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014EGUGA..1611137L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014EGUGA..1611137L">Tsunami Ionospheric warning and Ionospheric seismology</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Lognonne, Philippe; Rolland, Lucie; Rakoto, Virgile; Coisson, Pierdavide; Occhipinti, Giovanni; Larmat, Carene; Walwer, Damien; Astafyeva, Elvira; Hebert, Helene; Okal, Emile; Makela, Jonathan 2014-05-01 The last decade demonstrated that seismic waves and tsunamis are coupled to the ionosphere. Observations of Total Electron Content (TEC) and airglow perturbations of unique quality and amplitude were made during the Tohoku, 2011 giant Japan quake, and observations of much lower tsunamis down to a few cm in sea uplift are now routinely done, including for the Kuril 2006, Samoa 2009, Chili 2010, Haida Gwai 2012 tsunamis. This new branch of seismology is now mature enough to tackle the new challenge associated to the inversion of these data, with either the goal to provide from these data maps or profile of the earth surface vertical displacement (and therefore crucial information for tsunami warning system) or inversion, with ground and ionospheric data set, of the various parameters (atmospheric sound speed, viscosity, collision frequencies) controlling the coupling between the surface, lower atmosphere and the ionosphere. We first present the state of the art in the modeling of the tsunami-atmospheric coupling, including in terms of slight perturbation in the tsunami phase and group velocity and dependance of the coupling strength with local time, ocean depth and season. We then show the confrontation of modelled signals with observations. For tsunami, this is made with the different type of measurement having proven ionospheric tsunami detection over the last 5 years (ground and space GPS, Airglow), while we focus on GPS and GOCE observation for seismic waves. These observation systems allowed to track the propagation of the signal from the ground (with GPS and seismometers) to the neutral atmosphere (with infrasound sensors and GOCE drag measurement) to the ionosphere (with GPS TEC and airglow among other ionospheric sounding techniques). Modelling with different techniques (normal modes, spectral element methods, finite differences) are used and shown. While the fits of the waveform are generally very good, we analyse the differences and draw direction of future </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1983ReAer...1...13G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1983ReAer...1...13G">VHF electromagnetic wave propagation</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Gole, P. Theoretical and experimental study of large-scale VHF propagation characteristics is presented. Certain phenomena that are difficult to model, such as the effects of ground near the antenna, are examined from a purely experimental point of view. The characteristics of electromagnetic waves over a spherical surface and through a medium having a certain refractive index, such as is the case for waves propagated over the earth's surface, are analytically described. Two mathematical models are used, one for the case of the receiver being within the radioelectric horizon of the transmitter and the other for when it is not. Propagation phenomena likely to increase the false alarm probability of an air surveillance radar are briefly considered. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018SedG..364..242L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018SedG..364..242L">Boulder emplacement and remobilisation by cyclone and submarine landslide tsunami waves near Suva City, Fiji</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Lau, A. Y. Annie; Terry, James P.; Ziegler, Alan; Pratap, Arti; Harris, Daniel 2018-02-01 The characteristics of a reef-top boulder field created by a local submarine landslide tsunami are presented for the first time. Our examination of large reef-derived boulders deposited by the 1953 tsunami near Suva City, Fiji, revealed that shorter-than-normal-period tsunami waves generated by submarine landslides can create a boulder field resembling a storm boulder field due to relatively short boulder transport distances. The boulder-inferred 1953 tsunami flow velocity is estimated at over 9 m s- 1 at the reef edge. Subsequent events, for example Cyclone Kina (1993), appear to have remobilised some large boulders. While prior research has demonstrated headward retreat of Suva Canyon in response to the repeated occurrence of earthquakes over the past few millennia, our results highlight the lingering vulnerability of the Fijian coastlines to high-energy waves generated both in the presence (tsunami) and absence (storm) of submarine failures and/or earthquakes. To explain the age discrepancies of U-Th dated coral comprising the deposited boulders, we introduce a conceptual model showing the role of repeated episodes of tsunamigenic submarine landslides in removing reef front sections through collapse. Subsequent high-energy wave events transport boulders from exposed older sections of the reef front onto the reef where they are deposited as 'new' boulders, alongside freshly detached sections of the living reef. In similar situations where anachronistic deposits complicate the deposition signal, age-dating of the coral boulders should not be used as a proxy for determining the timing of the submarine landslides or the tsunamis that generated them. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011AGUFMNH13G..04M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011AGUFMNH13G..04M">An unified numerical simulation of seismic ground motion, ocean acoustics, coseismic deformations and tsunamis of 2011 Tohoku earthquake</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Maeda, T.; Furumura, T.; Noguchi, S.; Takemura, S.; Iwai, K.; Lee, S.; Sakai, S.; Shinohara, M. 2011-12-01 The fault rupture of the 2011 Tohoku (Mw9.0) earthquake spread approximately 550 km by 260 km with a long source rupture duration of ~200 s. For such large earthquake with a complicated source rupture process the radiation of seismic wave from the source rupture and initiation of tsunami due to the coseismic deformation is considered to be very complicated. In order to understand such a complicated process of seismic wave, coseismic deformation and tsunami, we proposed a unified approach for total modeling of earthquake induced phenomena in a single numerical scheme based on a finite-difference method simulation (Maeda and Furumura, 2011). This simulation model solves the equation of motion of based on the linear elastic theory with equilibrium between quasi-static pressure and gravity in the water column. The height of tsunami is obtained from this simulation as a vertical displacement of ocean surface. In order to simulate seismic waves, ocean acoustics, coseismic deformations, and tsunami from the 2011 Tohoku earthquake, we assembled a high-resolution 3D heterogeneous subsurface structural model of northern Japan. The area of simulation is 1200 km x 800 km and 120 km in depth, which have been discretized with grid interval of 1 km in horizontal directions and 0.25 km in vertical direction, respectively. We adopt a source-rupture model proposed by Lee et al. (2011) which is obtained by the joint inversion of teleseismic, near-field strong motion, and coseismic deformation. For conducting such a large-scale simulation, we fully parallelized our simulation code based on a domain-partitioning procedure which achieved a good speed-up by parallel computing up to 8192 core processors with parallel efficiency of 99.839%. The simulation result demonstrates clearly the process in which the seismic wave radiates from the complicated source rupture over the fault plane and propagating in heterogeneous structure of northern Japan. Then, generation of tsunami from coseismic </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015PApGe.172..791C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015PApGe.172..791C">New Tsunami Forecast Tools for the French Polynesia Tsunami Warning System</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Clément, Joël; Reymond, Dominique 2015-03-01 This paper presents the tsunami warning tools, which are used for the estimation of the seismic source parameters. These tools are grouped under a method called Preliminary Determination of Focal Mechanism_2 ( PDFM2), that has been developed at the French Polynesia Warning Center, in the framework of the system, as a plug-in concept. The first tool determines the seismic moment and the focal geometry (strike, dip, and slip), and the second tool identifies the "tsunami earthquakes" (earthquakes that cause much bigger tsunamis than their magnitude would imply). In a tsunami warning operation, initial assessment of the tsunami potential is based on location and magnitude. The usual quick magnitude methods which use waves, work fine for smaller earthquakes. For major earthquakes these methods drastically underestimate the magnitude and its tsunami potential because the radiated energy shifts to the longer period waves. Since French Polynesia is located far away from the subduction zones of the Pacific rim, the tsunami threat is not imminent, and this luxury of time allows to use the long period surface wave data to determine the true size of a major earthquake. The source inversion method presented in this paper uses a combination of surface waves amplitude spectra and P wave first motions. The advantage of using long period surface data is that there is a much more accurate determination of earthquake size, and the advantage of using P wave first motion is to have a better constrain of the focal geometry than using the surface waves alone. The method routinely gives stable results at minutes, with being the origin time of an earthquake. Our results are then compared to the Global Centroid Moment Tensor catalog for validating both the seismic moment and the source geometry. The second tool discussed in this paper is the slowness parameter and is the energy-to-moment ratio. It has been used to identify tsunami earthquakes, which are characterized by having unusual slow </li> <li> <a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70036505','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70036505">Combined effects of tectonic and landslide-generated Tsunami Runup at Seward, Alaska during the Mw 9.2 1964 earthquake</a> <a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a> Suleimani, E.; Nicolsky, D.J.; Haeussler, Peter J.; Hansen, R. 2011-01-01 We apply a recently developed and validated numerical model of tsunami propagation and runup to study the inundation of Resurrection Bay and the town of Seward by the 1964 Alaska tsunami. Seward was hit by both tectonic and landslide-generated tsunami waves during the Mw 9.2 1964 mega thrust earthquake. The earthquake triggered a series of submarine mass failures around the fjord, which resulted in land sliding of part of the coastline into the water, along with the loss of the port facilities. These submarine mass failures generated local waves in the bay within 5 min of the beginning of strong ground motion. Recent studies estimate the total volume of underwater slide material that moved in Resurrection Bay to be about 211 million m3 (Haeussler et al. in Submarine mass movements and their consequences, pp 269-278, 2007). The first tectonic tsunami wave arrived in Resurrection Bay about 30 min after the main shock and was about the same height as the local landslide-generated waves. Our previous numerical study, which focused only on the local land slide generated waves in Resurrection Bay, demonstrated that they were produced by a number of different slope failures, and estimated relative contributions of different submarine slide complexes into tsunami amplitudes (Suleimani et al. in Pure Appl Geophys 166:131-152, 2009). This work extends the previous study by calculating tsunami inundation in Resurrection Bay caused by the combined impact of landslide-generated waves and the tectonic tsunami, and comparing the composite inundation area with observations. To simulate landslide tsunami runup in Seward, we use a viscous slide model of Jiang and LeBlond (J Phys Oceanogr 24(3):559-572, 1994) coupled with nonlinear shallow water equations. The input data set includes a high resolution multibeam bathymetry and LIDAR topography grid of Resurrection Bay, and an initial thickness of slide material based on pre- and post-earthquake bathymetry difference maps. For </li> <li> <a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4872529','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4872529">Tsunami waves extensively resurfaced the shorelines of an early Martian ocean</a> <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a> Rodriguez, J. Alexis P.; Fairén, Alberto G.; Tanaka, Kenneth L.; Zarroca, Mario; Linares, Rogelio; Platz, Thomas; Komatsu, Goro; Miyamoto, Hideaki; Kargel, Jeffrey S.; Yan, Jianguo; Gulick, Virginia; Higuchi, Kana; Baker, Victor R.; Glines, Natalie 2016-01-01 It has been proposed that ~3.4 billion years ago an ocean fed by enormous catastrophic floods covered most of the Martian northern lowlands. However, a persistent problem with this hypothesis is the lack of definitive paleoshoreline features. Here, based on geomorphic and thermal image mapping in the circum-Chryse and northwestern Arabia Terra regions of the northern plains, in combination with numerical analyses, we show evidence for two enormous tsunami events possibly triggered by bolide impacts, resulting in craters ~30 km in diameter and occurring perhaps a few million years apart. The tsunamis produced widespread littoral landforms, including run-up water-ice-rich and bouldery lobes, which extended tens to hundreds of kilometers over gently sloping plains and boundary cratered highlands, as well as backwash channels where wave retreat occurred on highland-boundary surfaces. The ice-rich lobes formed in association with the younger tsunami, showing that their emplacement took place following a transition into a colder global climatic regime that occurred after the older tsunami event. We conclude that, on early Mars, tsunamis played a major role in generating and resurfacing coastal terrains. PMID:27196957 </li> <li> <a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27196957','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27196957">Tsunami waves extensively resurfaced the shorelines of an early Martian ocean.</a> <a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a> Rodriguez, J Alexis P; Fairén, Alberto G; Tanaka, Kenneth L; Zarroca, Mario; Linares, Rogelio; Platz, Thomas; Komatsu, Goro; Miyamoto, Hideaki; Kargel, Jeffrey S; Yan, Jianguo; Gulick, Virginia; Higuchi, Kana; Baker, Victor R; Glines, Natalie 2016-05-19 It has been proposed that ~3.4 billion years ago an ocean fed by enormous catastrophic floods covered most of the Martian northern lowlands. However, a persistent problem with this hypothesis is the lack of definitive paleoshoreline features. Here, based on geomorphic and thermal image mapping in the circum-Chryse and northwestern Arabia Terra regions of the northern plains, in combination with numerical analyses, we show evidence for two enormous tsunami events possibly triggered by bolide impacts, resulting in craters ~30 km in diameter and occurring perhaps a few million years apart. The tsunamis produced widespread littoral landforms, including run-up water-ice-rich and bouldery lobes, which extended tens to hundreds of kilometers over gently sloping plains and boundary cratered highlands, as well as backwash channels where wave retreat occurred on highland-boundary surfaces. The ice-rich lobes formed in association with the younger tsunami, showing that their emplacement took place following a transition into a colder global climatic regime that occurred after the older tsunami event. We conclude that, on early Mars, tsunamis played a major role in generating and resurfacing coastal terrains. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AGUFMNH41A1754B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUFMNH41A1754B">Tsunami Modeling and Prediction Using a Data Assimilation Technique with Kalman Filters</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Barnier, G.; Dunham, E. M. 2016-12-01 Earthquake-induced tsunamis cause dramatic damages along densely populated coastlines. It is difficult to predict and anticipate tsunami waves in advance, but if the earthquake occurs far enough from the coast, there may be enough time to evacuate the zones at risk. Therefore, any real-time information on the tsunami wavefield (as it propagates towards the coast) is extremely valuable for early warning systems. After the 2011 Tohoku earthquake, a dense tsunami-monitoring network (S-net) based on cabled ocean-bottom pressure sensors has been deployed along the Pacific coast in Northeastern Japan. Maeda et al. (GRL, 2015) introduced a data assimilation technique to reconstruct the tsunami wavefield in real time by combining numerical solution of the shallow water wave equations with additional terms penalizing the numerical solution for not matching observations. The penalty or gain matrix is determined though optimal interpolation and is independent of time. Here we explore a related data assimilation approach using the Kalman filter method to evolve the gain matrix. While more computationally expensive, the Kalman filter approach potentially provides more accurate reconstructions. We test our method on a 1D tsunami model derived from the Kozdon and Dunham (EPSL, 2014) dynamic rupture simulations of the 2011 Tohoku earthquake. For appropriate choices of model and data covariance matrices, the method reconstructs the tsunami wavefield prior to wave arrival at the coast. We plan to compare the Kalman filter method to the optimal interpolation method developed by Maeda et al. (GRL, 2015) and then to implement the method for 2D. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012AGUFMNH43B1648D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012AGUFMNH43B1648D">2011 Tohoku, Japan tsunami data available from the National Oceanic and Atmospheric Administration/National Geophysical Data Center</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Dunbar, P. K.; Mccullough, H. L.; Mungov, G.; Harris, E. 2012-12-01 The U.S. National Oceanic and Atmospheric Administration (NOAA) has primary responsibility for providing tsunami warnings to the Nation, and a leadership role in tsunami observations and research. A key component of this effort is easy access to authoritative data on past tsunamis, a responsibility of the National Geophysical Data Center (NGDC) and collocated World Service for Geophysics. Archive responsibilities include the global historical tsunami database, coastal tide-gauge data from US/NOAA operated stations, the Deep-ocean Assessment and Reporting of Tsunami (DART®) data, damage photos, as well as other related hazards data. Taken together, this integrated archive supports tsunami forecast, warning, research, mitigation and education efforts of NOAA and the Nation. Understanding the severity and timing of tsunami effects is important for tsunami hazard mitigation and warning. The global historical tsunami database includes the date, time, and location of the source event, magnitude of the source, event validity, maximum wave height, the total number of fatalities and dollar damage. The database contains additional information on run-ups (locations where tsunami waves were observed by eyewitnesses, field reconnaissance surveys, tide gauges, or deep ocean sensors). The run-up table includes arrival times, distance from the source, measurement type, maximum wave height, and the number of fatalities and damage for the specific run-up location. Tide gauge data are required for modeling the interaction of tsunami waves with the coast and for verifying propagation and inundation models. NGDC is the long-term archive for all NOAA coastal tide gauge data and is currently archiving 15-second to 1-minute water level data from the NOAA Center for Operational Oceanographic Products and Services (CO-OPS) and the NOAA Tsunami Warning Centers. DART® buoys, which are essential components of tsunami warning systems, are now deployed in all oceans, giving coastal communities </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013AGUFM.S32A..03F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013AGUFM.S32A..03F">Duration of Tsunami Generation Longer than Duration of Seismic Wave Generation in the 2011 Mw 9.0 Tohoku-Oki Earthquake</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Fujihara, S.; Korenaga, M.; Kawaji, K.; Akiyama, S. 2013-12-01 We try to compare and evaluate the nature of tsunami generation and seismic wave generation in occurrence of the 2011 Tohoku-Oki earthquake (hereafter, called as TOH11), in terms of two type of moment rate functions, inferred from finite source imaging of tsunami waveforms and seismic waveforms. Since 1970's, the nature of "tsunami earthquakes" has been discussed in many researches (e.g. Kanamori, 1972; Kanamori and Kikuchi, 1993; Kikuchi and Kanamori, 1995; Ide et al., 1993; Satake, 1994) mostly based on analysis of seismic waveform data , in terms of the "slow" nature of tsunami earthquakes (e.g., the 1992 Nicaragura earthquake). Although TOH11 is not necessarily understood as a tsunami earthquake, TOH11 is one of historical earthquakes that simultaneously generated large seismic waves and tsunami. Also, TOH11 is one of earthquakes which was observed both by seismic observation network and tsunami observation network around the Japanese islands. Therefore, for the purpose of analyzing the nature of tsunami generation, we try to utilize tsunami waveform data as much as possible. In our previous studies of TOH11 (Fujihara et al., 2012a; Fujihara et al., 2012b), we inverted tsunami waveforms at GPS wave gauges of NOWPHAS to image the spatio-temporal slip distribution. The "temporal" nature of our tsunami source model is generally consistent with the other tsunami source models (e.g., Satake et al, 2013). For seismic waveform inversion based on 1-D structure, here we inverted broadband seismograms at GSN stations based on the teleseismic body-wave inversion scheme (Kikuchi and Kanamori, 2003). Also, for seismic waveform inversion considering the inhomogeneous internal structure, we inverted strong motion seismograms at K-NET and KiK-net stations, based on 3-D Green's functions (Fujihara et al., 2013a; Fujihara et al., 2013b). The gross "temporal" nature of our seismic source models are generally consistent with the other seismic source models (e.g., Yoshida et al </li> <li> <a target="_blank" onclick="trackOutboundLink('https://eric.ed.gov/?q=landslides&pg=2&id=EJ721578','ERIC'); return false;" href="https://eric.ed.gov/?q=landslides&pg=2&id=EJ721578">What Causes Tsunamis?</a> <a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a> Mogil, H. Michael 2005-01-01 On December 26, 2004, a disastrous tsunami struck many parts of South Asia. The scope of this disaster has resulted in an outpouring of aid throughout the world and brought attention to the science of tsunamis. "Tsunami" means "harbor wave" in Japanese, and the Japanese have a long history of tsunamis. The word… </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2004AGUFMOS23D1350K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2004AGUFMOS23D1350K">Tsunami Risk for the Caribbean Coast</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Kozelkov, A. S.; Kurkin, A. A.; Pelinovsky, E. N.; Zahibo, N. 2004-12-01 The tsunami problem for the coast of the Caribbean basin is discussed. Briefly the historical data of tsunami in the Caribbean Sea are presented. Numerical simulation of potential tsunamis in the Caribbean Sea is performed in the framework of the nonlinear-shallow theory. The tsunami wave height distribution along the Caribbean Coast is computed. These results are used to estimate the far-field tsunami potential of various coastal locations in the Caribbean Sea. In fact, five zones with tsunami low risk are selected basing on prognostic computations, they are: the bay "Golfo de Batabano" and the coast of province "Ciego de Avila" in Cuba, the Nicaraguan Coast (between Bluefields and Puerto Cabezas), the border between Mexico and Belize, the bay "Golfo de Venezuela" in Venezuela. The analysis of historical data confirms that there was no tsunami in the selected zones. Also, the wave attenuation in the Caribbean Sea is investigated; in fact, wave amplitude decreases in an order if the tsunami source is located on the distance up to 1000 km from the coastal location. Both factors wave attenuation and wave height distribution should be taken into account in the planned warning system for the Caribbean Sea. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017EGUGA..1916564R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017EGUGA..1916564R">Inversion of the perturbation GPS-TEC data induced by tsunamis in order to estimate the sea level anomaly.</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Rakoto, Virgile; Lognonné, Philippe; Rolland, Lucie; Coïsson, Pierdavide; Drilleau, Mélanie 2017-04-01 Large underwater earthquakes (Mw > 7) can transmit part of their energy to the surrounding ocean through large sea-floor motions, generating tsunamis that propagate over long distances. The forcing effect of tsunami waves on the atmosphere generate internal gravity waves which produce detectable ionospheric perturbations when they reach the upper atmosphere. Theses perturbations are frequently observed in the total electron content (TEC) measured by the multi-frequency Global navigation Satellite systems (GNSS) data (e.g., GPS,GLONASS). In this paper, we performed for the first time an inversion of the sea level anomaly using the GPS TEC data using a least square inversion (LSQ) through a normal modes summation modeling technique. Using the tsunami of the 2012 Haida Gwaii in far field as a test case, we showed that the amplitude peak to peak of the sea level anomaly inverted using this method is below 10 % error. Nevertheless, we cannot invert the second wave arriving 20 minutes later. This second wave is generaly explain by the coastal reflection which the normal modeling does not take into account. Our technique is then applied to two other tsunamis : the 2006 Kuril Islands tsunami in far field, and the 2011 Tohoku tsunami in closer field. This demonstrates that the inversion using a normal mode approach is able to estimate fairly well the amplitude of the first arrivals of the tsunami. In the future, we plan to invert in real the TEC data in order to retrieve the tsunami height. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014EGUGA..16.8561H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014EGUGA..16.8561H">Landslide-generated tsunamis in a perialpine lake: Historical events and numerical models</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Hilbe, Michael; Anselmetti, Flavio S. 2014-05-01 Many of the perialpine lakes in Central Europe - the large, glacier-carved basins formed during the Pleistocene glaciations of the Alps - have proven to be environments prone to subaquatic landsliding. Among these, Lake Lucerne (Switzerland) has a particularly well-established record of subaquatic landslides and related tsunamis. Its sedimentary archive documents numerous landslides over the entire Holocene, which have either been triggered by earthquakes, or which occurred apparently spontaneously, possibly due to rapid sediment accumulation on delta slopes. Due to their controlled boundary conditions and the possibility to be investigated on a complete basinal scale, such lacustrine tsunamis may be used as textbook analogons for their marine counterparts. Two events in the 17th century illustrate these processes and their consequences: In AD 1601, an earthquake (Mw ~ 5.9) led to widespread failure of the sediment drape covering the lateral slopes in several basins. The resulting landslides generated tsunami waves that reached a runup of several metres, as reported in historical accounts. The waves caused widespread damage as well as loss of lives in communities along the shores. In AD 1687, the apparently spontaneous collapse of a river delta in the lake led to similar waves that damaged nearby villages. Based on detailed information on topography, bathymetry and the geometry of the landslide deposits, numerical simulations combining two-dimensional, depth-averaged models for landslide propagation, as well as for tsunami generation, propagation and inundation, are able to reproduce most of the reported tsunami effects for these events. Calculated maximum runup of the waves is 6 to >10 m in the directly affected lake basins, but significantly less in neighbouring basins. Flat alluvial plains adjacent to the most heavily affected areas are inundated over distances of several hundred metres. Taken as scenarios for possible future events, these past events suggest </li> <li> <a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19870045671&hterms=relationship+form&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3Drelationship%2Bform','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19870045671&hterms=relationship+form&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3Drelationship%2Bform">Relationship between directions of wave and energy propagation for cold plasma waves</a> <a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a> Musielak, Zdzislaw E. 1986-01-01 The dispersion relation for plasma waves is considered in the 'cold' plasma approximation. General formulas for the dependence of the phase and group velocities on the direction of wave propagation with respect to the local magnetic field are obtained for a cold magnetized plasma. The principal cold plasma resonances and cut-off frequencies are defined for an arbitrary angle and are used to establish basic regimes of frequency where the cold plasma waves can propagate or can be evanescent. The relationship between direction of wave and energy propagation, for cold plasma waves in hydrogen atmosphere, is presented in the form of angle diagrams (angle between group velocity and magnetic field versus angle between phase velocity and magnetic field) and polar diagrams (also referred to as 'Friedrich's diagrams') for different directions of wave propagation. Morphological features of the diagrams as well as some critical angles of propagation are discussed. </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_8");'>8</a></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li class="active">10</li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> </div> <div id="page_11" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li class="active">11</li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="201"> <li> <a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20050170625','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20050170625">Offshore Breaking of Impact Tsunami: Van Dorn was Right</a> <a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a> Korycansky, D. G.; Lynett, P. J. 2005-01-01 Tsunami generated by the impacts of asteroids and comets into the Earth s oceans are widely recognized as a potentially catastrophic hazard to the Earth s population (e.g. Chapman and Morrison 1994, Nature, 367, 33; Hills et al. 1994, in Hazards Due to Comets and Asteroids, (ed. T. Gehrels), 779; Atkinson et al. 2000, Report of the UK Task Force on Potentially Hazardous NEOs; Ward and Asphaug 2000, Icarus, 145, 64). A peculiarity of ocean impacts is the potential global effects of an impact that would otherwise be of only regional or local importance should it occur on land. This is, of course, due to the ability of waves to propagate globally, as seen by the terrible effects of the recent earthquake off the coast of Sumatra. The overall process of an impact tsunami is complex and falls into several distinct phases: 1) initial impact of the bolide into the ocean and formation of a transient cavity in the water, 2) collapse of the cavity and propagation of large waves from the impact center outward over deep water (typically several km in depth), 3) initial effects on wave amplitude as shallower water of the continental slope is reached ("wave shoaling"), possible breaking of waves in relatively shallow water (less than 100 m depth), on continental shelves, and 5) final contact of waves with the shore and their progression onto dry land ("run-up" and "run-in"). Here we report on numerical calculations (and semi-analytic theory) covering phases 3 and 4. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFMNH23A0244J','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFMNH23A0244J">Tsunami Amplitude Estimation from Real-Time GNSS.</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Jeffries, C.; MacInnes, B. T.; Melbourne, T. I. 2017-12-01 Tsunami early warning systems currently comprise modeling of observations from the global seismic network, deep-ocean DART buoys, and a global distribution of tide gauges. While these tools work well for tsunamis traveling teleseismic distances, saturation of seismic magnitude estimation in the near field can result in significant underestimation of tsunami excitation for local warning. Moreover, DART buoy and tide gauge observations cannot be used to rectify the underestimation in the available time, typically 10-20 minutes, before local runup occurs. Real-time GNSS measurements of coseismic offsets may be used to estimate finite faulting within 1-2 minutes and, in turn, tsunami excitation for local warning purposes. We describe here a tsunami amplitude estimation algorithm; implemented for the Cascadia subduction zone, that uses continuous GNSS position streams to estimate finite faulting. The system is based on a time-domain convolution of fault slip that uses a pre-computed catalog of hydrodynamic Green's functions generated with the GeoClaw shallow-water wave simulation software and maps seismic slip along each section of the fault to points located off the Cascadia coast in 20m of water depth and relies on the principle of the linearity in tsunami wave propagation. The system draws continuous slip estimates from a message broker, convolves the slip with appropriate Green's functions which are then superimposed to produce wave amplitude at each coastal location. The maximum amplitude and its arrival time are then passed into a database for subsequent monitoring and display. We plan on testing this system using a suite of synthetic earthquakes calculated for Cascadia whose ground motions are simulated at 500 existing Cascadia GPS sites, as well as real earthquakes for which we have continuous GNSS time series and surveyed runup heights, including Maule, Chile 2010 and Tohoku, Japan 2011. This system has been implemented in the CWU Geodesy Lab for the Cascadia </li> <li> <a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/1083297','DOE-PATENT-XML'); return false;" href="https://www.osti.gov/servlets/purl/1083297">Reconstruction of nonlinear wave propagation</a> <a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a> Fleischer, Jason W; Barsi, Christopher; Wan, Wenjie 2013-04-23 Disclosed are systems and methods for characterizing a nonlinear propagation environment by numerically propagating a measured output waveform resulting from a known input waveform. The numerical propagation reconstructs the input waveform, and in the process, the nonlinear environment is characterized. In certain embodiments, knowledge of the characterized nonlinear environment facilitates determination of an unknown input based on a measured output. Similarly, knowledge of the characterized nonlinear environment also facilitates formation of a desired output based on a configurable input. In both situations, the input thus characterized and the output thus obtained include features that would normally be lost in linear propagations. Such features can include evanescent waves and peripheral waves, such that an image thus obtained are inherently wide-angle, farfield form of microscopy. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AGUFMNH33A1903F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AGUFMNH33A1903F">Landslide-Generated Tsunami Model for Quick Hazard Assessment</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Franz, M.; Rudaz, B.; Locat, J.; Jaboyedoff, M.; Podladchikov, Y. 2015-12-01 Alpine regions are likely to be areas at risk regarding to landslide-induced tsunamis, because of the proximity between lakes and potential instabilities and due to the concentration of the population in valleys and on the lakes shores. In particular, dam lakes are often surrounded by steep slopes and frequently affect the stability of the banks. In order to assess comprehensively this phenomenon together with the induced risks, we have developed a 2.5D numerical model which aims to simulate the propagation of the landslide, the generation and the propagation of the wave and eventually the spread on the shores or the associated downstream flow. To perform this task, the process is done in three steps. Firstly, the geometry of the sliding mass is constructed using the Sloping Local Base Level (SLBL) concept. Secondly, the propagation of this volume is performed using a model based on viscous flow equations. Finally, the wave generation and its propagation are simulated using the shallow water equations stabilized by the Lax-Friedrichs scheme. The transition between wet and dry bed is performed by the combination of the two latter sets of equations. The proper behavior of our model is demonstrated by; (1) numerical tests from Toro (2001), and (2) by comparison with a real event where the horizontal run-up distance is known (Nicolet landslide, Quebec, Canada). The model is of particular interest due to its ability to perform quickly the 2.5D geometric model of the landslide, the tsunami simulation and, consequently, the hazard assessment. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AGUFMNH23A1852S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AGUFMNH23A1852S">Benchmarking on Tsunami Currents with ComMIT</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Sharghi vand, N.; Kanoglu, U. 2015-12-01 There were no standards for the validation and verification of tsunami numerical models before 2004 Indian Ocean tsunami. Even, number of numerical models has been used for inundation mapping effort, evaluation of critical structures, etc. without validation and verification. After 2004, NOAA Center for Tsunami Research (NCTR) established standards for the validation and verification of tsunami numerical models (Synolakis et al. 2008 Pure Appl. Geophys. 165, 2197-2228), which will be used evaluation of critical structures such as nuclear power plants against tsunami attack. NCTR presented analytical, experimental and field benchmark problems aimed to estimate maximum runup and accepted widely by the community. Recently, benchmark problems were suggested by the US National Tsunami Hazard Mitigation Program Mapping & Modeling Benchmarking Workshop: Tsunami Currents on February 9-10, 2015 at Portland, Oregon, USA (http://nws.weather.gov/nthmp/index.html). These benchmark problems concentrated toward validation and verification of tsunami numerical models on tsunami currents. Three of the benchmark problems were: current measurement of the Japan 2011 tsunami in Hilo Harbor, Hawaii, USA and in Tauranga Harbor, New Zealand, and single long-period wave propagating onto a small-scale experimental model of the town of Seaside, Oregon, USA. These benchmark problems were implemented in the Community Modeling Interface for Tsunamis (ComMIT) (Titov et al. 2011 Pure Appl. Geophys. 168, 2121-2131), which is a user-friendly interface to the validated and verified Method of Splitting Tsunami (MOST) (Titov and Synolakis 1995 J. Waterw. Port Coastal Ocean Eng. 121, 308-316) model and is developed by NCTR. The modeling results are compared with the required benchmark data, providing good agreements and results are discussed. Acknowledgment: The research leading to these results has received funding from the European Union's Seventh Framework Programme (FP7/2007-2013) under grant </li> <li> <a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70195105','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70195105">Probabilistic tsunami hazard analysis: Multiple sources and global applications</a> <a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a> Grezio, Anita; Babeyko, Andrey; Baptista, Maria Ana; Behrens, Jörn; Costa, Antonio; Davies, Gareth; Geist, Eric L.; Glimsdal, Sylfest; González, Frank I.; Griffin, Jonathan; Harbitz, Carl B.; LeVeque, Randall J.; Lorito, Stefano; Løvholt, Finn; Omira, Rachid; Mueller, Christof; Paris, Raphaël; Parsons, Thomas E.; Polet, Jascha; Power, William; Selva, Jacopo; Sørensen, Mathilde B.; Thio, Hong Kie 2017-01-01 Applying probabilistic methods to infrequent but devastating natural events is intrinsically challenging. For tsunami analyses, a suite of geophysical assessments should be in principle evaluated because of the different causes generating tsunamis (earthquakes, landslides, volcanic activity, meteorological events, and asteroid impacts) with varying mean recurrence rates. Probabilistic Tsunami Hazard Analyses (PTHAs) are conducted in different areas of the world at global, regional, and local scales with the aim of understanding tsunami hazard to inform tsunami risk reduction activities. PTHAs enhance knowledge of the potential tsunamigenic threat by estimating the probability of exceeding specific levels of tsunami intensity metrics (e.g., run-up or maximum inundation heights) within a certain period of time (exposure time) at given locations (target sites); these estimates can be summarized in hazard maps or hazard curves. This discussion presents a broad overview of PTHA, including (i) sources and mechanisms of tsunami generation, emphasizing the variety and complexity of the tsunami sources and their generation mechanisms, (ii) developments in modeling the propagation and impact of tsunami waves, and (iii) statistical procedures for tsunami hazard estimates that include the associated epistemic and aleatoric uncertainties. Key elements in understanding the potential tsunami hazard are discussed, in light of the rapid development of PTHA methods during the last decade and the globally distributed applications, including the importance of considering multiple sources, their relative intensities, probabilities of occurrence, and uncertainties in an integrated and consistent probabilistic framework. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017RvGeo..55.1158G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017RvGeo..55.1158G">Probabilistic Tsunami Hazard Analysis: Multiple Sources and Global Applications</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Grezio, Anita; Babeyko, Andrey; Baptista, Maria Ana; Behrens, Jörn; Costa, Antonio; Davies, Gareth; Geist, Eric L.; Glimsdal, Sylfest; González, Frank I.; Griffin, Jonathan; Harbitz, Carl B.; LeVeque, Randall J.; Lorito, Stefano; Løvholt, Finn; Omira, Rachid; Mueller, Christof; Paris, Raphaël.; Parsons, Tom; Polet, Jascha; Power, William; Selva, Jacopo; Sørensen, Mathilde B.; Thio, Hong Kie 2017-12-01 Applying probabilistic methods to infrequent but devastating natural events is intrinsically challenging. For tsunami analyses, a suite of geophysical assessments should be in principle evaluated because of the different causes generating tsunamis (earthquakes, landslides, volcanic activity, meteorological events, and asteroid impacts) with varying mean recurrence rates. Probabilistic Tsunami Hazard Analyses (PTHAs) are conducted in different areas of the world at global, regional, and local scales with the aim of understanding tsunami hazard to inform tsunami risk reduction activities. PTHAs enhance knowledge of the potential tsunamigenic threat by estimating the probability of exceeding specific levels of tsunami intensity metrics (e.g., run-up or maximum inundation heights) within a certain period of time (exposure time) at given locations (target sites); these estimates can be summarized in hazard maps or hazard curves. This discussion presents a broad overview of PTHA, including (i) sources and mechanisms of tsunami generation, emphasizing the variety and complexity of the tsunami sources and their generation mechanisms, (ii) developments in modeling the propagation and impact of tsunami waves, and (iii) statistical procedures for tsunami hazard estimates that include the associated epistemic and aleatoric uncertainties. Key elements in understanding the potential tsunami hazard are discussed, in light of the rapid development of PTHA methods during the last decade and the globally distributed applications, including the importance of considering multiple sources, their relative intensities, probabilities of occurrence, and uncertainties in an integrated and consistent probabilistic framework. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://library.lanl.gov/tsunami/ts261.pdf','USGSPUBS'); return false;" href="http://library.lanl.gov/tsunami/ts261.pdf">Preliminary analysis of the earthquake (MW 8.1) and tsunami of April 1, 2007, in the Solomon Islands, southwestern Pacific Ocean</a> <a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a> Fisher, Michael A.; Geist, Eric L.; Sliter, Ray; Wong, Florence L.; Reiss, Carol; Mann, Dennis M. 2007-01-01 On April 1, 2007, a destructive earthquake (Mw 8.1) and tsunami struck the central Solomon Islands arc in the southwestern Pacific Ocean. The earthquake had a thrust-fault focal mechanism and occurred at shallow depth (between 15 km and 25 km) beneath the island arc. The combined effects of the earthquake and tsunami caused dozens of fatalities and thousands remain without shelter. We present a preliminary analysis of the Mw-8.1 earthquake and resulting tsunami. Multichannel seismic-reflection data collected during 1984 show the geologic structure of the arc's frontal prism within the earthquake's rupture zone. Modeling tsunami-wave propagation indicates that some of the islands are so close to the earthquake epicenter that they were hard hit by tsunami waves as soon as 5 min. after shaking began, allowing people scant time to react. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018OcMod.124...61B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018OcMod.124...61B">Amplification of drawdown and runup over Hawaii's insular shelves by tsunami N-waves from mega Aleutian earthquakes</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Bai, Yefei; Yamazaki, Yoshiki; Cheung, Kwok Fai 2018-04-01 The latest tsunami evacuation maps of Hawaii include an extreme scenario triggered by an Mw 9.3 Aleutian earthquake with large near-trench rupture. The tectonic plate motion produces concentrated seafloor uplift toward the deepest part of the trench generating a tsunami with strong non-hydrostatic characters. A parametric study shows the skewed seafloor uplift produces a dispersive leading crest followed by a prominent trough in the form of an N-wave. The trough maintains its depth across the ocean in the absence of side lobes and dispersion. Shifting of the uplift toward the trench tends to deepen the trough, but has diminishing effects on the wave crest away from the source. While the attenuated leading crest produces relatively moderate runup on north-facing shores of the Hawaiian Islands, with matching of the N-wave and shelf resonance periods, the trough produces an impulsive drawdown followed by an energetic upswing with unprecedented runup for a far-field tsunami. A set of control computations without dispersion reaffirms that a non-hydrostatic model is essential to account for these complex wave processes from the source to the shore. This case study highlights the unique tsunami hazards posed by the Aleutians to Hawaii and the role of wave troughs in delineating the impacts for hazard assessment and engineering design. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017EGUGA..19.3941S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017EGUGA..19.3941S">Real-Time Detection of Tsunami Ionospheric Disturbances with a Stand-Alone GNSS Receiver: An Integration of GPS and Galileo Systems</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Savastano, Giorgio; Komjathy, Attila; Verkhoglyadova, Olga; Wei, Yong; Mazzoni, Augusto; Crespi, Mattia 2017-04-01 Tsunamis can produce gravity waves that propagate up to the ionosphere generating disturbed electron densities in the E and F regions. These ionospheric disturbances are studied in detail using ionospheric total electron content (TEC) measurements collected by continuously operating ground-based receivers from the Global Navigation Satellite Systems (GNSS). Here, we present results using a new approach, named VARION (Variometric Approach for Real-Time Ionosphere Observation), and for the first time, we estimate slant TEC (sTEC) variations in a real-time scenario from GPS and Galileo constellations. Specifically, we study the 2016 New Zealand tsunami event using GNSS receivers with multi-constellation tracking capabilities located in the Pacific region. We compare sTEC estimates obtained using GPS and Galileo constellations. The efficiency of the real-time sTEC estimation using the VARION algorithm has been demonstrated for the 2012 Haida Gwaii tsunami event. TEC variations induced by the tsunami event are computed using 56 GPS receivers in Hawai'i. We observe TEC perturbations with amplitudes up to 0.25 TEC units and traveling ionospheric disturbances moving away from the epicenter at a speed of about 316 m/s. We present comparisons with the real-time tsunami model MOST (Method of Splitting Tsunami) provided by the NOAA Center for Tsunami Research. We observe variations in TEC that correlate well in time and space with the propagating tsunami waves. We conclude that the integration of different satellite constellations is a crucial step forward to increasing the reliability of real-time tsunami detection systems using ground-based GNSS receivers as an augmentation to existing tsunami early warning systems. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010RvGeo..48.4006W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010RvGeo..48.4006W">Impact of a Cosmic Body into Earth's Ocean and the Generation of Large Tsunami Waves: Insight from Numerical Modeling</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Wünnemann, K.; Collins, G. S.; Weiss, R. 2010-12-01 The strike of a cosmic body into a marine environment differs in several respects from impact on land. Oceans cover approximately 70% of the Earth's surface, implying not only that oceanic impact is a very likely scenario for future impacts but also that most impacts in Earth's history must have happened in marine environments. Therefore, the study of oceanic impact is imperative in two respects: (1) to quantify the hazard posed by future oceanic impacts, including the potential threat of large impact-generated tsunami-like waves, and (2) to reconstruct Earth's impact record by accounting for the large number of potentially undiscovered crater structures in the ocean crust. Reconstruction of the impact record is of crucial importance both for assessing the frequency of collision events in the past and for better predicting the probability of future impact. We summarize the advances in the study of oceanic impact over the last decades and focus in particular on how numerical models have improved our understanding of cratering in the oceanic environment and the generation of waves by impact. We focus on insight gleaned from numerical modeling studies into the deceleration of the projectile by the water, cratering of the ocean floor, the late stage modification of the crater due to gravitational collapse, and water resurge. Furthermore, we discuss the generation and propagation of large tsunami-like waves as a result of a strike of a cosmic body in marine environments. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFM.S33G2942G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFM.S33G2942G">Far-field tsunami of 2017 Mw 8.1 Tehuantepec, Mexico earthquake recorded by Chilean tide gauge network: Implications for tsunami warning systems</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> González-Carrasco, J. F.; Benavente, R. F.; Zelaya, C.; Núñez, C.; Gonzalez, G. 2017-12-01 The 2017 Mw 8.1, Tehuantepec earthquake generated a moderated tsunami, which was registered in near-field tide gauges network activating a tsunami threat state for Mexico issued by PTWC. In the case of Chile, the forecast of tsunami waves indicate amplitudes less than 0.3 meters above the tide level, advising an informative state of threat, without activation of evacuation procedures. Nevertheless, during sea level monitoring of network we detect wave amplitudes (> 0.3 m) indicating a possible change of threat state. Finally, NTWS maintains informative level of threat based on mathematical filtering analysis of sea level records. After 2010 Mw 8.8, Maule earthquake, the Chilean National Tsunami Warning System (NTWS) has increased its observational capabilities to improve early response. Most important operational efforts have focused on strengthening tide gauge network for national area of responsibility. Furthermore, technological initiatives as Integrated Tsunami Prediction and Warning System (SIPAT) has segmented the area of responsibility in blocks to focus early warning and evacuation procedures on most affected coastal areas, while maintaining an informative state for distant areas of near-field earthquake. In the case of far-field events, NTWS follow the recommendations proposed by Pacific Tsunami Warning Center (PTWC), including a comprehensive monitoring of sea level records, such as tide gauges and DART (Deep-Ocean Assessment and Reporting of Tsunami) buoys, to evaluate the state of tsunami threat in the area of responsibility. The main objective of this work is to analyze the first-order physical processes involved in the far-field propagation and coastal impact of tsunami, including implications for decision-making of NTWS. To explore our main question, we construct a finite-fault model of the 2017, Mw 8.1 Tehuantepec earthquake. We employ the rupture model to simulate a transoceanic tsunami modeled by Neowave2D. We generate synthetic time series at </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013EGUGA..15.5595L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013EGUGA..15.5595L">New method to determine initial surface water displacement at tsunami source</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Lavrentyev, Mikhail; Romanenko, Alexey; Tatarintsev, Pavel 2013-04-01 Friday, March 11, 2011 at 05:46:23 UTC, Japan was struck by an 8.9-magnitude earthquake near its Northeastern coast. This is one of the largest earthquakes that Japan has ever experienced. Tsunami waves swept away houses and cars and caused massive human losses. To predict tsunami wave parameters better and faster, we propose to improve data inversion scheme and achieve the performance gain of data processing. One of the reasons of inaccurate predictions of tsunami parameters is that very little information is available about the initial disturbance of the sea bed at tsunami source. In this paper, we suggest a new way of improving the quality of tsunami source parameters prediction. Modern computational technologies can accurately calculate tsunami wave propagation over the deep ocean provided that the initial displacement (perturbation of the sea bed at tsunami source) is known [4]. Direct geophysical measurements provide the location of an earthquake hypocenter and its magnitude (the released energy evaluation). Among the methods of determination of initial displacement the following ones should be considered. Calculation through the known fault structure and available seismic information. This method is widely used and provides useful information. However, even if the exact knowledge about rock blocks shifts is given, recalculation in terms of sea bed displacement is needed. This results in a certain number of errors. GPS data analysis. This method was developed after the December 2004 event in the Indian Ocean. A good correlation between dry land based GPS sensors and tsunami wave parameters was observed in the particular case of the West coast of Sumatra, Indonesia. This approach is very unique and can hardly been used in other geo locations. Satellite image analysis. The resolution of modern satellite images has dramatically improved. In the future, correct data of sea surface displacement will probably be available in real time, right after a tsunamigenic </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017JGRC..122.9605W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017JGRC..122.9605W">How Do Tides and Tsunamis Interact in a Highly Energetic Channel? The Case of Canal Chacao, Chile</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Winckler, Patricio; Sepúlveda, Ignacio; Aron, Felipe; Contreras-López, Manuel 2017-12-01 This study aims at understanding the role of tidal level, speed, and direction in tsunami propagation in highly energetic tidal channels. The main goal is to comprehend whether tide-tsunami interactions enhance/reduce elevation, currents speeds, and arrival times, when compared to pure tsunami models and to simulations in which tides and tsunamis are linearly superimposed. We designed various numerical experiments to compute the tsunami propagation along Canal Chacao, a highly energetic channel in the Chilean Patagonia lying on a subduction margin prone to megathrust earthquakes. Three modeling approaches were implemented under the same seismic scenario: a tsunami model with a constant tide level, a series of six composite models in which independent tide and tsunami simulations are linearly superimposed, and a series of six tide-tsunami nonlinear interaction models (full models). We found that hydrodynamic patterns differ significantly among approaches, being the composite and full models sensitive to both the tidal phase at which the tsunami is triggered and the local depth of the channel. When compared to full models, composite models adequately predicted the maximum surface elevation, but largely overestimated currents. The amplitude and arrival time of the tsunami-leading wave computed with the full model was found to be strongly dependent on the direction of the tidal current and less responsive to the tide level and the tidal current speed. These outcomes emphasize the importance of addressing more carefully the interactions of tides and tsunamis on hazard assessment studies. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013NHESS..13.1795T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013NHESS..13.1795T">The UBO-TSUFD tsunami inundation model: validation and application to a tsunami case study focused on the city of Catania, Italy</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Tinti, S.; Tonini, R. 2013-07-01 Nowadays numerical models are a powerful tool in tsunami research since they can be used (i) to reconstruct modern and historical events, (ii) to cast new light on tsunami sources by inverting tsunami data and observations, (iii) to build scenarios in the frame of tsunami mitigation plans, and (iv) to produce forecasts of tsunami impact and inundation in systems of early warning. In parallel with the general recognition of the importance of numerical tsunami simulations, the demand has grown for reliable tsunami codes, validated through tests agreed upon by the tsunami community. This paper presents the tsunami code UBO-TSUFD that has been developed at the University of Bologna, Italy, and that solves the non-linear shallow water (NSW) equations in a Cartesian frame, with inclusion of bottom friction and exclusion of the Coriolis force, by means of a leapfrog (LF) finite-difference scheme on a staggered grid and that accounts for moving boundaries to compute sea inundation and withdrawal at the coast. Results of UBO-TSUFD applied to four classical benchmark problems are shown: two benchmarks are based on analytical solutions, one on a plane wave propagating on a flat channel with a constant slope beach; and one on a laboratory experiment. The code is proven to perform very satisfactorily since it reproduces quite well the benchmark theoretical and experimental data. Further, the code is applied to a realistic tsunami case: a scenario of a tsunami threatening the coasts of eastern Sicily, Italy, is defined and discussed based on the historical tsunami of 11 January 1693, i.e. one of the most severe events in the Italian history. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFMNH22A..01T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFMNH22A..01T">Tsunami waves generated by dynamically triggered aftershocks of the 2010 Haiti earthquake</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Ten Brink, U. S.; Wei, Y.; Fan, W.; Miller, N. C.; Granja, J. L. 2017-12-01 Dynamically-triggered aftershocks, thought to be set off by the passage of surface waves, are currently not considered in tsunami warnings, yet may produce enough seafloor deformation to generate tsunamis on their own, as judged from new findings about the January 12, 2010 Haiti earthquake tsunami in the Caribbean Sea. This tsunami followed the Mw7.0 Haiti mainshock, which resulted from a complex rupture along the north shore of Tiburon Peninsula, not beneath the Caribbean Sea. The mainshock, moreover, had a mixed strike-slip and thrust focal mechanism. There were no recorded aftershocks in the Caribbean Sea, only small coastal landslides and rock falls on the south shore of Tiburon Peninsula. Nevertheless, a tsunami was recorded on deep-sea DART buoy 42407 south of the Dominican Republic and on the Santo Domingo tide gauge, and run-ups of ≤3 m were observed along a 90-km-long stretch of the SE Haiti coast. Three dynamically-triggered aftershocks south of Haiti have been recently identified within the coda of the mainshock (<200 s) by analyzing P wave arrivals recorded by dense seismic arrays, parsing the arrivals into 20-s-long stacks, and back-projecting the arrivals to the vicinity of the main shock (50-300 km). Two of the aftershocks, coming 20-40 s and 40-60 s after the mainshock, plot along NW-SE-trending submarine ridges in the Caribbean Sea south of Haiti. The third event, 120-140 s was located along the steep eastern slope of Bahoruco Peninsula, which is delineated by a normal fault. Forward tsunami models show that the arrival times of the DART buoy and tide gauge times are best fit by the earliest of the three aftershocks, with a Caribbean source 60 km SW of the mainshock rupture zone. Preliminary inversion of the DART buoy time series for fault locations and orientations confirms the location of the first source, but requires an additional unidentified source closer to shore 40 km SW of the mainshock rupture zone. This overall agreement between </li> <li> <a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/23510921','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/23510921">Longitudinal nonlinear wave propagation through soft tissue.</a> <a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a> Valdez, M; Balachandran, B 2013-04-01 In this paper, wave propagation through soft tissue is investigated. A primary aim of this investigation is to gain a fundamental understanding of the influence of soft tissue nonlinear material properties on the propagation characteristics of stress waves generated by transient loadings. Here, for computational modeling purposes, the soft tissue is modeled as a nonlinear visco-hyperelastic material, the geometry is assumed to be one-dimensional rod geometry, and uniaxial propagation of longitudinal waves is considered. By using the linearized model, a basic understanding of the characteristics of wave propagation is developed through the dispersion relation and in terms of the propagation speed and attenuation. In addition, it is illustrated as to how the linear system can be used to predict brain tissue material parameters through the use of available experimental ultrasonic attenuation curves. Furthermore, frequency thresholds for wave propagation along internal structures, such as axons in the white matter of the brain, are obtained through the linear analysis. With the nonlinear material model, the authors analyze cases in which one of the ends of the rods is fixed and the other end is subjected to a loading. Two variants of the nonlinear model are analyzed and the associated predictions are compared with the predictions of the corresponding linear model. The numerical results illustrate that one of the imprints of the nonlinearity on the wave propagation phenomenon is the steepening of the wave front, leading to jump-like variations in the stress wave profiles. This phenomenon is a consequence of the dependence of the local wave speed on the local deformation of the material. As per the predictions of the nonlinear material model, compressive waves in the structure travel faster than tensile waves. Furthermore, it is found that wave pulses with large amplitudes and small elapsed times are attenuated over shorter spans. This feature is due to the elevated </li> <li> <a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/103551-propagation-fluidization-combustion-wave','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/103551-propagation-fluidization-combustion-wave">Propagation of a fluidization - combustion wave</a> <a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a> Pron, G.P.; Gusachenko, L.K.; Zarko, V.E. 1994-05-01 A fluidization-combustion wave propagating through a fixed and initially cool bed was created by igniting coal at the top surface of the bed. The proposed physical interpretation of the phenomenon is in qualitative agreement with the experimental dependences of the characteristics of the process on determining parameters. A kindling regime with forced wave propagation is suggested. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011AGUFM.U53D0075W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011AGUFM.U53D0075W">The Pacific Tsunami Warning Center's Response to the Tohoku Earthquake and Tsunami</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Weinstein, S. A.; Becker, N. C.; Shiro, B.; Koyanagi, K. K.; Sardina, V.; Walsh, D.; Wang, D.; McCreery, C. S.; Fryer, G. J.; Cessaro, R. K.; Hirshorn, B. F.; Hsu, V. 2011-12-01 The largest Pacific basin earthquake in 47 years, and also the largest magnitude earthquake since the Sumatra 2004 earthquake, struck off of the east coast of the Tohoku region of Honshu, Japan at 5:46 UTC on 11 March 2011. The Tohoku earthquake (Mw 9.0) generated a massive tsunami with runups of up to 40m along the Tohoku coast. The tsunami waves crossed the Pacific Ocean causing significant damage as far away as Hawaii, California, and Chile, thereby becoming the largest, most destructive tsunami in the Pacific Basin since 1960. Triggers on the seismic stations at Erimo, Hokkaido (ERM) and Matsushiro, Honshu (MAJO), alerted Pacific Tsunami Warning Center (PTWC) scientists 90 seconds after the earthquake began. Four minutes after its origin, and about one minute after the earthquake's rupture ended, PTWC issued an observatory message reporting a preliminary magnitude of 7.5. Eight minutes after origin time, the Japan Meteorological Agency (JMA) issued its first international tsunami message in its capacity as the Northwest Pacific Tsunami Advisory Center. In accordance with international tsunami warning system protocols, PTWC then followed with its first international tsunami warning message using JMA's earthquake parameters, including an Mw of 7.8. Additional Mwp, mantle wave, and W-phase magnitude estimations based on the analysis of later-arriving seismic data at PTWC revealed that the earthquake magnitude reached at least 8.8, and that a destructive tsunami would likely be crossing the Pacific Ocean. The earthquake damaged the nearest coastal sea-level station located 90 km from the epicenter in Ofunato, Japan. The NOAA DART sensor situated 600 km off the coast of Sendai, Japan, at a depth of 5.6 km recorded a tsunami wave amplitude of nearly two meters, making it by far the largest tsunami wave ever recorded by a DART sensor. Thirty minutes later, a coastal sea-level station at Hanasaki, Japan, 600 km from the epicenter, recorded a tsunami wave amplitude of </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFMNH23A0240B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFMNH23A0240B">Tsunami Scenario in the Nankai Trough, Japan, Based on the GPS-A and GNSS Velocities</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Bock, Y.; Watanabe, S. I.; Melgar, D.; Tadokoro, K. 2017-12-01 We present two local tsunami scenarios for the Nankai trough, Japan, an area of significant seismic risk, using GPS-A and GNSS velocities and two different plate interface geometries to better assess the slip deficit rate. We expand on the work of Yokota et al. [2016, Nature] by: (1) Adding seafloor data collected by Nagoya University [Tadokoro et al., 2012 GRL] at the Kumano basin, (2) Aligning the geodetic data to the Nankai block (forearc sliver) to the tectonic model of Loveless and Meade [2010 JGR] - the earlier work ignored block boundaries such as the Median Tectonic Line (MTL) and may have overestimated the slip deficit rate, (3) Considering two different plate interface geometries - it is essential to use the accurate depth of the plate interface, especially for the offshore region where the faults are located near the observation sites, (4) Estimating and correcting for the postseismic displacements of the 2004 southeastern off the Kii Peninsula earthquakes (MJMA 7.1, 7.4). Based upon the refined model, we calculate the coseismic displacements and tsunami wave propagation assuming that a hundred years of constant slip deficit accumulation is released instantaneously. We used the open source software GeoClaw v5.3.1, which solves the two-dimensional shallow water equations with the finite volume technique [LeVeque, 2002 Cambridge University Press], for the local tsunami scenarios. We present the expected tsunami propagation models and wave profiles based on the geodetically-derived distribution of slip, stressing the importance of identifying fault locations and geometries. The location of the downdip edge of the coseismic rupture is essential to assess whether the coastal area would subside or not. The sensitivity to the plate interface geometries is increased in the near-trough region. From the point of view of disaster prevention, subsidence at the southern coast would heighten the tsunami runup distance (e.g., at gauges in Shimotsu and Irago). Further </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li class="active">11</li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> </div> <div id="page_12" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li class="active">12</li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="221"> <li> <a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26093439','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26093439">Conversion of evanescent Lamb waves into propagating waves via a narrow aperture edge.</a> <a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a> Yan, Xiang; Yuan, Fuh-Gwo 2015-06-01 This paper presents a quantitative study of conversion of evanescent Lamb waves into propagating in isotropic plates. The conversion is substantiated by prescribing time-harmonic Lamb displacements/tractions through a narrow aperture at an edge of a semi-infinite plate. Complex-valued dispersion and group velocity curves are employed to characterize the conversion process. The amplitude coefficient of the propagating Lamb modes converted from evanescent is quantified based on the complex reciprocity theorem via a finite element analysis. The power flow generated into the plate can be separated into radiative and reactive parts made on the basis of propagating and evanescent Lamb waves, where propagating Lamb waves are theoretically proved to radiate pure real power flow, and evanescent Lamb waves carry reactive pure imaginary power flow. The propagating power conversion efficiency is then defined to quantitatively describe the conversion. The conversion efficiency is strongly frequency dependent and can be significant. With the converted propagating waves from evanescent, sensors at far-field can recapture some localized damage information that is generally possessed in evanescent waves and may have potential application in structural health monitoring. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017PApGe.174.2925G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017PApGe.174.2925G">Fault Slip Distribution of the 2016 Fukushima Earthquake Estimated from Tsunami Waveforms</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Gusman, Aditya Riadi; Satake, Kenji; Shinohara, Masanao; Sakai, Shin'ichi; Tanioka, Yuichiro 2017-08-01 The 2016 Fukushima normal-faulting earthquake (Mjma 7.4) occurred 40 km off the coast of Fukushima within the upper crust. The earthquake generated a moderate tsunami which was recorded by coastal tide gauges and offshore pressure gauges. First, the sensitivity of tsunami waveforms to fault dimensions and depths was examined and the best size and depth were determined. Tsunami waveforms computed based on four available focal mechanisms showed that a simple fault striking northeast-southwest and dipping southeast (strike = 45°, dip = 41°, rake = -95°) yielded the best fit to the observed waveforms. This fault geometry was then used in a tsunami waveform inversion to estimate the fault slip distribution. A large slip of 3.5 m was located near the surface and the major slip region covered an area of 20 km × 20 km. The seismic moment, calculated assuming a rigidity of 2.7 × 1010 N/m2 was 3.70 × 1019 Nm, equivalent to Mw = 7.0. This is slightly larger than the moments from the moment tensor solutions (Mw 6.9). Large secondary tsunami peaks arrived approximately an hour after clear initial peaks were recorded by the offshore pressure gauges and the Sendai and Ofunato tide gauges. Our tsunami propagation model suggests that the large secondary tsunami signals were from tsunami waves reflected off the Fukushima coast. A rather large tsunami amplitude of 75 cm at Kuji, about 300 km north of the source, was comparable to those recorded at stations located much closer to the epicenter, such as Soma and Onahama. Tsunami simulations and ray tracing for both real and artificial bathymetry indicate that a significant portion of the tsunami wave was refracted to the coast located around Kuji and Miyako due to bathymetry effects. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://www.dtic.mil/docs/citations/AD1013882','DTIC-ST'); return false;" href="http://www.dtic.mil/docs/citations/AD1013882">Elastic Wave Propagation Mechanisms in Underwater Acoustic Environments</a> <a target="_blank" href="http://www.dtic.mil/">DTIC Science & Technology</a> 2015-09-30 Elastic wave propagation mechanisms in underwater acoustic environments Scott D. Frank Marist College Department of Mathematics Poughkeepsie...conversion from elastic propagation to acoustic propagation, and intense interface waves on underwater acoustic environments with elastic bottoms...acoustic propagation will be considered as a means to predict the presence of elastic ice layers. APPROACH In a cylindrically symmetric environment </li> <li> <a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20030110765&hterms=tsunami&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Dtsunami','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20030110765&hterms=tsunami&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Dtsunami">Impact Tsunami Calculations: Hydrodynamical Simulations vs. Linear Theory</a> <a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a> Korycansky, E.; Asphaug, E.; Ward, S. N. 2003-01-01 Tsunamis generated by the impacts of asteroids and comets into the Earth oceans are widely recognized as a potential catastrophic hazard to the Earth s population. Our general conclusion is that linear theory is a reasonably accurate guide to behavior of tsunamis generated by impactors of moderate size, where the initial transient impact cavity is of moderate depth compared to the ocean depth. This is particularly the case for long wavelength waves that propagate fastest and would reach coastlines first. Such tsunamis would be generated in the open ocean by impactors of 300 meters in diameter, which might be expected to strike the Earth once every few thousand years, on the average. Larger impactors produce cavities deep enough to reach the ocean floor; even here, linear theory is applicable if the starting point is chosen at a later phase in the calculation when the impact crater has slumped back to produce a cavity of moderate depth and slope. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012AGUFMNH33A1643C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012AGUFMNH33A1643C">Validation of NEOWAVE with Measurements from the 2011 Tohoku Tsunami</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Cheung, K.; Yamazaki, Y. 2012-12-01 An accurate and reliable numerical model is essential in mapping tsunami hazards for mitigation and preparedness. The model NEOWAVE (Non-hydrostatic Evolution of Ocean WAVEs) is being used for tsunami inundation mapping in Hawaii, American Samoa, the Gulf coast states, and Puerto Rico. In addition to the benchmarks established by the National Tsunami Hazard Mitigation Program, we have been conducting a thorough investigation of NEOWAVE's capability in reproducing the 2011 Tohoku tsunami and its impact across the Pacific. The shock-capturing non-hydrostatic model is well suited to handle tsunami conditions in a variety of coastal environments in the near and far field. It describes dispersive waves through non-hydrostatic pressure and vertical velocity, which also account for tsunami generation from time histories of seafloor deformation. The semi-implicit, staggered finite difference model captures flow discontinuities associated with bores or hydraulic jumps through a momentum conservation scheme. The model supports up to five levels of two-way nested grids in spherical coordinates to describe tsunami processes of varying time and spatial scales from the open ocean to the coast. We first define the source mechanism through forward modeling of the near-field tsunami recorded by coastal and deep-ocean buoys. A finite-fault solution based on teleseismic P-wave inversion serves as the starting point of the iterative process, in which the source parameters are systematically adjusted to achieve convergence of the computed tsunami with the near-field records. The capability of NEOWAVE in modeling propagation of the tsunami is evaluated with DART data across the Pacific as well as water-level and current measurements in Hawaii. These far-field water-level records, which are not considered in the forward modeling, also provide an independently assessment of the source model. The computed runup and inundation are compared with measurements along Northeastern Japan coasts </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012AGUFMNH31D..08T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012AGUFMNH31D..08T">Tsunami hazard assessment along the U. S. East Coast</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Tajalli Bakhsh, T.; Grilli, S. T.; Harris, J. C.; Kirby, J. T.; Shi, F.; Tehranirad, B. 2012-12-01 In 2005, the National Tsunami Hazard Mitigation Program (NTHMP) was tasked by Congress to develop tsunami inundation maps for the entire US coastline. This work provides an overview of the modeling work related to the development inundation maps along the US east coast. In this region the paucity of historical tsunami records and lack of paleotsunami observations yields a large uncertainty on the source and magnitude of potential extreme tsunami events, and their related coastal hazard. In the Atlantic Ocean basin significant tsunami hazard may result from far-field earthquakes, such as a repeat of the M8.9 Lisbon 1755 event in the Azores convergence zone, or a hypothetical extreme M9 earthquake in the Puerto Rico Trench (PRT). Additionally, it is believed that a repeat of one of the large historical collapses, identified at the toe of the Cumbre Vieja volcano on La Palma (Canary Islands; i.e., with a maximum volume of 450 km3), could pose a major tsunami hazard to the entire US east coast. Finally, in the near-field, large submarine mass failure (SMF) scars have been mapped by USGS, particularly North of the Carolinas (e.g., Currituck), which are believed to have caused past tsunamis. Large SMFs can be triggered by moderate seismicity (M7 or so), such as can occur on the east coast. In fact, one of the few historical tsunamis that significantly affected this region was caused by the 1929 Grand Bank underwater slide, which was triggered by a M7.2 earthquake. In this work we identify and parameterize all potential tsunami sources affecting the US east coast, and perform simulations of tsunami generation, propagation, and coastal impact in a series of increasingly resolved nested grids. Following this methodology, tsunami inundation maps are currently being developed for a few of the most affected areas. In simulations, we use a robust and well-validated Fully Nonlinear Boussinesq long-wave model (FUNWAVE-TVD), on Cartesian or spherical grids. Coseismic tsunami </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFMNH22A..02S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFMNH22A..02S">Tsunami hazard assessments with consideration of uncertain earthquakes characteristics</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Sepulveda, I.; Liu, P. L. F.; Grigoriu, M. D.; Pritchard, M. E. 2017-12-01 The uncertainty quantification of tsunami assessments due to uncertain earthquake characteristics faces important challenges. First, the generated earthquake samples must be consistent with the properties observed in past events. Second, it must adopt an uncertainty propagation method to determine tsunami uncertainties with a feasible computational cost. In this study we propose a new methodology, which improves the existing tsunami uncertainty assessment methods. The methodology considers two uncertain earthquake characteristics, the slip distribution and location. First, the methodology considers the generation of consistent earthquake slip samples by means of a Karhunen Loeve (K-L) expansion and a translation process (Grigoriu, 2012), applicable to any non-rectangular rupture area and marginal probability distribution. The K-L expansion was recently applied by Le Veque et al. (2016). We have extended the methodology by analyzing accuracy criteria in terms of the tsunami initial conditions. Furthermore, and unlike this reference, we preserve the original probability properties of the slip distribution, by avoiding post sampling treatments such as earthquake slip scaling. Our approach is analyzed and justified in the framework of the present study. Second, the methodology uses a Stochastic Reduced Order model (SROM) (Grigoriu, 2009) instead of a classic Monte Carlo simulation, which reduces the computational cost of the uncertainty propagation. The methodology is applied on a real case. We study tsunamis generated at the site of the 2014 Chilean earthquake. We generate earthquake samples with expected magnitude Mw 8. We first demonstrate that the stochastic approach of our study generates consistent earthquake samples with respect to the target probability laws. We also show that the results obtained from SROM are more accurate than classic Monte Carlo simulations. We finally validate the methodology by comparing the simulated tsunamis and the tsunami records for </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AGUFMNH23B..06H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AGUFMNH23B..06H">A Hybrid Tsunami Risk Model for Japan</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Haseemkunju, A. V.; Smith, D. F.; Khater, M.; Khemici, O.; Betov, B.; Scott, J. 2014-12-01 Around the margins of the Pacific Ocean, denser oceanic plates slipping under continental plates cause subduction earthquakes generating large tsunami waves. The subducting Pacific and Philippine Sea plates create damaging interplate earthquakes followed by huge tsunami waves. It was a rupture of the Japan Trench subduction zone (JTSZ) and the resultant M9.0 Tohoku-Oki earthquake that caused the unprecedented tsunami along the Pacific coast of Japan on March 11, 2011. EQECAT's Japan Earthquake model is a fully probabilistic model which includes a seismo-tectonic model describing the geometries, magnitudes, and frequencies of all potential earthquake events; a ground motion model; and a tsunami model. Within the much larger set of all modeled earthquake events, fault rupture parameters for about 24000 stochastic and 25 historical tsunamigenic earthquake events are defined to simulate tsunami footprints using the numerical tsunami model COMCOT. A hybrid approach using COMCOT simulated tsunami waves is used to generate inundation footprints, including the impact of tides and flood defenses. Modeled tsunami waves of major historical events are validated against observed data. Modeled tsunami flood depths on 30 m grids together with tsunami vulnerability and financial models are then used to estimate insured loss in Japan from the 2011 tsunami. The primary direct report of damage from the 2011 tsunami is in terms of the number of buildings damaged by municipality in the tsunami affected area. Modeled loss in Japan from the 2011 tsunami is proportional to the number of buildings damaged. A 1000-year return period map of tsunami waves shows high hazard along the west coast of southern Honshu, on the Pacific coast of Shikoku, and on the east coast of Kyushu, primarily associated with major earthquake events on the Nankai Trough subduction zone (NTSZ). The highest tsunami hazard of more than 20m is seen on the Sanriku coast in northern Honshu, associated with the JTSZ. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016EGUGA..18.2925V','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016EGUGA..18.2925V">Validation and Comparison of 2D and 3D Codes for Nearshore Motion of Long Waves Using Benchmark Problems</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Velioǧlu, Deniz; Cevdet Yalçıner, Ahmet; Zaytsev, Andrey 2016-04-01 Tsunamis are huge waves with long wave periods and wave lengths that can cause great devastation and loss of life when they strike a coast. The interest in experimental and numerical modeling of tsunami propagation and inundation increased considerably after the 2011 Great East Japan earthquake. In this study, two numerical codes, FLOW 3D and NAMI DANCE, that analyze tsunami propagation and inundation patterns are considered. Flow 3D simulates linear and nonlinear propagating surface waves as well as long waves by solving three-dimensional Navier-Stokes (3D-NS) equations. NAMI DANCE uses finite difference computational method to solve 2D depth-averaged linear and nonlinear forms of shallow water equations (NSWE) in long wave problems, specifically tsunamis. In order to validate these two codes and analyze the differences between 3D-NS and 2D depth-averaged NSWE equations, two benchmark problems are applied. One benchmark problem investigates the runup of long waves over a complex 3D beach. The experimental setup is a 1:400 scale model of Monai Valley located on the west coast of Okushiri Island, Japan. Other benchmark problem is discussed in 2015 National Tsunami Hazard Mitigation Program (NTHMP) Annual meeting in Portland, USA. It is a field dataset, recording the Japan 2011 tsunami in Hilo Harbor, Hawaii. The computed water surface elevation and velocity data are compared with the measured data. The comparisons showed that both codes are in fairly good agreement with each other and benchmark data. The differences between 3D-NS and 2D depth-averaged NSWE equations are highlighted. All results are presented with discussions and comparisons. Acknowledgements: Partial support by Japan-Turkey Joint Research Project by JICA on earthquakes and tsunamis in Marmara Region (JICA SATREPS - MarDiM Project), 603839 ASTARTE Project of EU, UDAP-C-12-14 project of AFAD Turkey, 108Y227, 113M556 and 213M534 projects of TUBITAK Turkey, RAPSODI (CONCERT_Dis-021) of CONCERT </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AGUFMNH13A3716B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AGUFMNH13A3716B">Development of Parallel Code for the Alaska Tsunami Forecast Model</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Bahng, B.; Knight, W. R.; Whitmore, P. 2014-12-01 The Alaska Tsunami Forecast Model (ATFM) is a numerical model used to forecast propagation and inundation of tsunamis generated by earthquakes and other means in both the Pacific and Atlantic Oceans. At the U.S. National Tsunami Warning Center (NTWC), the model is mainly used in a pre-computed fashion. That is, results for hundreds of hypothetical events are computed before alerts, and are accessed and calibrated with observations during tsunamis to immediately produce forecasts. ATFM uses the non-linear, depth-averaged, shallow-water equations of motion with multiply nested grids in two-way communications between domains of each parent-child pair as waves get closer to coastal waters. Even with the pre-computation the task becomes non-trivial as sub-grid resolution gets finer. Currently, the finest resolution Digital Elevation Models (DEM) used by ATFM are 1/3 arc-seconds. With a serial code, large or multiple areas of very high resolution can produce run-times that are unrealistic even in a pre-computed approach. One way to increase the model performance is code parallelization used in conjunction with a multi-processor computing environment. NTWC developers have undertaken an ATFM code-parallelization effort to streamline the creation of the pre-computed database of results with the long term aim of tsunami forecasts from source to high resolution shoreline grids in real time. Parallelization will also permit timely regeneration of the forecast model database with new DEMs; and, will make possible future inclusion of new physics such as the non-hydrostatic treatment of tsunami propagation. The purpose of our presentation is to elaborate on the parallelization approach and to show the compute speed increase on various multi-processor systems. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AGUFMNH21A3833H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AGUFMNH21A3833H">Multiscale Modelling of the 2011 Tohoku Tsunami with Fluidity: Coastal Inundation and Run-up.</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Hill, J.; Martin-Short, R.; Piggott, M. D.; Candy, A. S. 2014-12-01 Tsunami-induced flooding represents one of the most dangerous natural hazards to coastal communities around the world, as exemplified by Tohoku tsunami of March 2011. In order to further understand this hazard and to design appropriate mitigation it is necessary to develop versatile, accurate software capable of simulating large scale tsunami propagation and interaction with coastal geomorphology on a local scale. One such software package is Fluidity, an open source, finite element, multiscale, code that is capable of solving the fully three dimensional Navier-Stokes equations on unstructured meshes. Such meshes are significantly better at representing complex coastline shapes than structured meshes and have the advantage of allowing variation in element size across a domain. Furthermore, Fluidity incorporates a novel wetting and drying algorithm, which enables accurate, efficient simulation of tsunami run-up over complex, multiscale, topography. Fluidity has previously been demonstrated to accurately simulate the 2011 Tohoku tsunami (Oishi et al 2013) , but its wetting and drying facility has not yet been tested on a geographical scale. This study makes use of Fluidity to simulate the 2011 Tohoku tsunami and its interaction with Japan's eastern shoreline, including coastal flooding. The results are validated against observations made by survey teams, aerial photographs and previous modelling efforts in order to evaluate Fluidity's current capabilities and suggest methods of future improvement. The code is shown to perform well at simulating flooding along the topographically complex Tohoku coast of Japan, with major deviations between model and observation arising mainly due to limitations imposed by bathymetry resolution, which could be improved in future. In theory, Fluidity is capable of full multiscale tsunami modelling, thus enabling researchers to understand both wave propagation across ocean basins and flooding of coastal landscapes down to interaction </li> <li> <a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70035272','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70035272">Near-field hazard assessment of March 11, 2011 Japan Tsunami sources inferred from different methods</a> <a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a> Wei, Y.; Titov, V.V.; Newman, A.; Hayes, G.; Tang, L.; Chamberlin, C. 2011-01-01 Tsunami source is the origin of the subsequent transoceanic water waves, and thus the most critical component in modern tsunami forecast methodology. Although impractical to be quantified directly, a tsunami source can be estimated by different methods based on a variety of measurements provided by deep-ocean tsunameters, seismometers, GPS, and other advanced instruments, some in real time, some in post real-time. Here we assess these different sources of the devastating March 11, 2011 Japan tsunami by model-data comparison for generation, propagation and inundation in the near field of Japan. This study provides a comparative study to further understand the advantages and shortcomings of different methods that may be potentially used in real-time warning and forecast of tsunami hazards, especially in the near field. The model study also highlights the critical role of deep-ocean tsunami measurements for high-quality tsunami forecast, and its combination with land GPS measurements may lead to better understanding of both the earthquake mechanisms and tsunami generation process. ?? 2011 MTS. </li> <li> <a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5399489','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5399489">Real-Time Detection of Tsunami Ionospheric Disturbances with a Stand-Alone GNSS Receiver: A Preliminary Feasibility Demonstration</a> <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a> Savastano, Giorgio; Komjathy, Attila; Verkhoglyadova, Olga; Mazzoni, Augusto; Crespi, Mattia; Wei, Yong; Mannucci, Anthony J. 2017-01-01 It is well known that tsunamis can produce gravity waves that propagate up to the ionosphere generating disturbed electron densities in the E and F regions. These ionospheric disturbances can be studied in detail using ionospheric total electron content (TEC) measurements collected by continuously operating ground-based receivers from the Global Navigation Satellite Systems (GNSS). Here, we present results using a new approach, named VARION (Variometric Approach for Real-Time Ionosphere Observation), and estimate slant TEC (sTEC) variations in a real-time scenario. Using the VARION algorithm we compute TEC variations at 56 GPS receivers in Hawaii as induced by the 2012 Haida Gwaii tsunami event. We observe TEC perturbations with amplitudes of up to 0.25 TEC units and traveling ionospheric perturbations (TIDs) moving away from the earthquake epicenter at an approximate speed of 316 m/s. We perform a wavelet analysis to analyze localized variations of power in the TEC time series and we find perturbation periods consistent with a tsunami typical deep ocean period. Finally, we present comparisons with the real-time tsunami MOST (Method of Splitting Tsunami) model produced by the NOAA Center for Tsunami Research and we observe variations in TEC that correlate in time and space with the tsunami waves. PMID:28429754 </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017NatSR...746607S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017NatSR...746607S">Real-Time Detection of Tsunami Ionospheric Disturbances with a Stand-Alone GNSS Receiver: A Preliminary Feasibility Demonstration</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Savastano, Giorgio; Komjathy, Attila; Verkhoglyadova, Olga; Mazzoni, Augusto; Crespi, Mattia; Wei, Yong; Mannucci, Anthony J. 2017-04-01 It is well known that tsunamis can produce gravity waves that propagate up to the ionosphere generating disturbed electron densities in the E and F regions. These ionospheric disturbances can be studied in detail using ionospheric total electron content (TEC) measurements collected by continuously operating ground-based receivers from the Global Navigation Satellite Systems (GNSS). Here, we present results using a new approach, named VARION (Variometric Approach for Real-Time Ionosphere Observation), and estimate slant TEC (sTEC) variations in a real-time scenario. Using the VARION algorithm we compute TEC variations at 56 GPS receivers in Hawaii as induced by the 2012 Haida Gwaii tsunami event. We observe TEC perturbations with amplitudes of up to 0.25 TEC units and traveling ionospheric perturbations (TIDs) moving away from the earthquake epicenter at an approximate speed of 316 m/s. We perform a wavelet analysis to analyze localized variations of power in the TEC time series and we find perturbation periods consistent with a tsunami typical deep ocean period. Finally, we present comparisons with the real-time tsunami MOST (Method of Splitting Tsunami) model produced by the NOAA Center for Tsunami Research and we observe variations in TEC that correlate in time and space with the tsunami waves. </li> <li> <a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28429754','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28429754">Real-Time Detection of Tsunami Ionospheric Disturbances with a Stand-Alone GNSS Receiver: A Preliminary Feasibility Demonstration.</a> <a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a> Savastano, Giorgio; Komjathy, Attila; Verkhoglyadova, Olga; Mazzoni, Augusto; Crespi, Mattia; Wei, Yong; Mannucci, Anthony J 2017-04-21 It is well known that tsunamis can produce gravity waves that propagate up to the ionosphere generating disturbed electron densities in the E and F regions. These ionospheric disturbances can be studied in detail using ionospheric total electron content (TEC) measurements collected by continuously operating ground-based receivers from the Global Navigation Satellite Systems (GNSS). Here, we present results using a new approach, named VARION (Variometric Approach for Real-Time Ionosphere Observation), and estimate slant TEC (sTEC) variations in a real-time scenario. Using the VARION algorithm we compute TEC variations at 56 GPS receivers in Hawaii as induced by the 2012 Haida Gwaii tsunami event. We observe TEC perturbations with amplitudes of up to 0.25 TEC units and traveling ionospheric perturbations (TIDs) moving away from the earthquake epicenter at an approximate speed of 316 m/s. We perform a wavelet analysis to analyze localized variations of power in the TEC time series and we find perturbation periods consistent with a tsunami typical deep ocean period. Finally, we present comparisons with the real-time tsunami MOST (Method of Splitting Tsunami) model produced by the NOAA Center for Tsunami Research and we observe variations in TEC that correlate in time and space with the tsunami waves. </li> <li> <a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/29390792','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/29390792">Lamb wave propagation in monocrystalline silicon wafers.</a> <a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a> Fromme, Paul; Pizzolato, Marco; Robyr, Jean-Luc; Masserey, Bernard 2018-01-01 Monocrystalline silicon wafers are widely used in the photovoltaic industry for solar panels with high conversion efficiency. Guided ultrasonic waves offer the potential to efficiently detect micro-cracks in the thin wafers. Previous studies of ultrasonic wave propagation in silicon focused on effects of material anisotropy on bulk ultrasonic waves, but the dependence of the wave propagation characteristics on the material anisotropy is not well understood for Lamb waves. The phase slowness and beam skewing of the two fundamental Lamb wave modes A 0 and S 0 were investigated. Experimental measurements using contact wedge transducer excitation and laser measurement were conducted. Good agreement was found between the theoretically calculated angular dependency of the phase slowness and measurements for different propagation directions relative to the crystal orientation. Significant wave skew and beam widening was observed experimentally due to the anisotropy, especially for the S 0 mode. Explicit finite element simulations were conducted to visualize and quantify the guided wave beam skew. Good agreement was found for the A 0 mode, but a systematic discrepancy was observed for the S 0 mode. These effects need to be considered for the non-destructive testing of wafers using guided waves. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2003PApGe.160..509W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2003PApGe.160..509W">Wave Propagation, Scattering and Imaging Using Dual-domain One-way and One-return Propagators</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Wu, R.-S. - Dual-domain one-way propagators implement wave propagation in heterogeneous media in mixed domains (space-wavenumber domains). One-way propagators neglect wave reverberations between heterogeneities but correctly handle the forward multiple-scattering including focusing/defocusing, diffraction, refraction and interference of waves. The algorithm shuttles between space-domain and wavenumber-domain using FFT, and the operations in the two domains are self-adaptive to the complexity of the media. The method makes the best use of the operations in each domain, resulting in efficient and accurate propagators. Due to recent progress, new versions of dual-domain methods overcame some limitations of the classical dual-domain methods (phase-screen or split-step Fourier methods) and can propagate large-angle waves quite accurately in media with strong velocity contrasts. These methods can deliver superior image quality (high resolution/high fidelity) for complex subsurface structures. One-way and one-return (De Wolf approximation) propagators can be also applied to wave-field modeling and simulations for some geophysical problems. In the article, a historical review and theoretical analysis of the Born, Rytov, and De Wolf approximations are given. A review on classical phase-screen or split-step Fourier methods is also given, followed by a summary and analysis of the new dual-domain propagators. The applications of the new propagators to seismic imaging and modeling are reviewed with several examples. For seismic imaging, the advantages and limitations of the traditional Kirchhoff migration and time-space domain finite-difference migration, when applied to 3-D complicated structures, are first analyzed. Then the special features, and applications of the new dual-domain methods are presented. Three versions of GSP (generalized screen propagators), the hybrid pseudo-screen, the wide-angle Padé-screen, and the higher-order generalized screen propagators are discussed. Recent </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016PEPS....3...12K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016PEPS....3...12K">Examination of the largest-possible tsunamis (Level 2) generated along the Nankai and Suruga troughs during the past 4000 years based on studies of tsunami deposits from the 2011 Tohoku-oki tsunami</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Kitamura, Akihisa 2016-12-01 Japanese historical documents reveal that Mw 8 class earthquakes have occurred every 100-150 years along the Suruga and Nankai troughs since the 684 Hakuho earthquake. These earthquakes have commonly caused large tsunamis with wave heights of up to 10 m in the Japanese coastal area along the Suruga and Nankai troughs. From the perspective of tsunami disaster management, these tsunamis are designated as Level 1 tsunamis and are the basis for the design of coastal protection facilities. A Mw 9.0 earthquake (the 2011 Tohoku-oki earthquake) and a mega-tsunami with wave heights of 10-40 m struck the Pacific coast of the northeastern Japanese mainland on 11 March 2011, and far exceeded pre-disaster predictions of wave height. Based on the lessons learned from the 2011 Tohoku-oki earthquake, the Japanese Government predicted the tsunami heights of the largest-possible tsunami (termed a Level 2 tsunami) that could be generated in the Suruga and Nankai troughs. The difference in wave heights between Level 1 and Level 2 tsunamis exceeds 20 m in some areas, including the southern Izu Peninsula. This study reviews the distribution of prehistorical tsunami deposits and tsunami boulders during the past 4000 years, based on previous studies in the coastal area of Shizuoka Prefecture, Japan. The results show that a tsunami deposit dated at 3400-3300 cal BP can be traced between the Shimizu, Shizuoka and Rokken-gawa lowlands, whereas no geologic evidence related to the corresponding tsunami (the Rokken-gawa-Oya tsunami) was found on the southern Izu Peninsula. Thus, the Rokken-gawa-Oya tsunami is not classified as a Level 2 tsunami. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016EGUGA..1812085D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016EGUGA..1812085D">Numerical tsunami hazard assessment of the submarine volcano Kick 'em Jenny in high resolution are</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Dondin, Frédéric; Dorville, Jean-Francois Marc; Robertson, Richard E. A. 2016-04-01 (VolcFlow-Matlab). The wave have been propagated on the coastal area of two island with high resolution bathymetry (Litto3D). Keywords - Volcano edifice stability, Collapse volume estimate, Tsunami impact, Kick 'em Jenny, wave propagation, Lesser Antilles, High resolution bathymetry </li> <li> <a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70024701','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70024701">Evaluating tsunami hazards from debris flows</a> <a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a> Watts, P.; Walder, J.S.; , 2003-01-01 Debris flows that enter water bodies may have significant kinetic energy, some of which is transferred to water motion or waves that can impact shorelines and structures. The associated hazards depend on the location of the affected area relative to the point at which the debris flow enters the water. Three distinct regions (splash zone, near field, and far field) may be identified. Experiments demonstrate that characteristics of the near field water wave, which is the only coherent wave to emerge from the splash zone, depend primarily on debris flow volume, debris flow submerged time of motion, and water depth at the point where debris flow motion stops. Near field wave characteristics commonly may be used as & proxy source for computational tsunami propagation. This result is used to assess hazards associated with potential debris flows entering a reservoir in the northwestern USA. ?? 2003 Millpress,. </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li class="active">12</li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> </div> <div id="page_13" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li class="active">13</li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="241"> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018PApGe.tmp.1331V','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018PApGe.tmp.1331V">Performance Comparison of NAMI DANCE and FLOW-3D® Models in Tsunami Propagation, Inundation and Currents using NTHMP Benchmark Problems</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Velioglu Sogut, Deniz; Yalciner, Ahmet Cevdet 2018-06-01 Field observations provide valuable data regarding nearshore tsunami impact, yet only in inundation areas where tsunami waves have already flooded. Therefore, tsunami modeling is essential to understand tsunami behavior and prepare for tsunami inundation. It is necessary that all numerical models used in tsunami emergency planning be subject to benchmark tests for validation and verification. This study focuses on two numerical codes, NAMI DANCE and FLOW-3D®, for validation and performance comparison. NAMI DANCE is an in-house tsunami numerical model developed by the Ocean Engineering Research Center of Middle East Technical University, Turkey and Laboratory of Special Research Bureau for Automation of Marine Research, Russia. FLOW-3D® is a general purpose computational fluid dynamics software, which was developed by scientists who pioneered in the design of the Volume-of-Fluid technique. The codes are validated and their performances are compared via analytical, experimental and field benchmark problems, which are documented in the ``Proceedings and Results of the 2011 National Tsunami Hazard Mitigation Program (NTHMP) Model Benchmarking Workshop'' and the ``Proceedings and Results of the NTHMP 2015 Tsunami Current Modeling Workshop". The variations between the numerical solutions of these two models are evaluated through statistical error analysis. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AGUFM.S21A4388R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AGUFM.S21A4388R">New Perspective of Tsunami Deposit Investigations: Insight from the 1755 Lisbon Tsunami in Martinique, Lesser Antilles.</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Roger, J.; Clouard, V.; Moizan, E. 2014-12-01 The recent devastating tsunamis having occurred during the last decades have highlighted the essential necessity to deploy operationnal warning systems and educate coastal populations. This could not be prepared correctly without a minimum knowledge about the tsunami history. That is the case of the Lesser Antilles islands, where a few handfuls of tsunamis have been reported over the past 5 centuries, some of them leading to notable destructions and inundations. But the lack of accurate details for most of the historical tsunamis and the limited period during which we could find written information represents an important problem for tsunami hazard assessment in this region. Thus, it is of major necessity to try to find other evidences of past tsunamis by looking for sedimentary deposits. Unfortunately, island tropical environments do not seem to be the best places to keep such deposits burried. In fact, heavy rainfalls, storms, and all other phenomena leading to coastal erosion, and associated to human activities such as intensive sugarcane cultivation in coastal flat lands, could caused the loss of potential tsunami deposits. Lots of places have been accurately investigated within the Lesser Antilles (from Sainte-Lucia to the British Virgin Islands) the last 3 years and nothing convincing has been found. That is when archeaological investigations excavated a 8-cm thick sandy and shelly layer in downtown Fort-de-France (Martinique), wedged between two well-identified layers of human origin (Fig. 1), that we found new hope: this sandy layer has been quickly attributed without any doubt to the 1755 tsunami, using on one hand the information provided by historical reports of the construction sites, and on the other hand by numerical modeling of the tsunami (wave heights, velocity fields, etc.) showing the ability of this transoceanic tsunami to wrap around the island after ~7 hours of propagation, enter Fort-de-France's Bay with enough energy to carry sediments, and </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017SMaS...26l5027C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017SMaS...26l5027C">Propagation and dispersion of shock waves in magnetoelastic materials</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Crum, R. S.; Domann, J. P.; Carman, G. P.; Gupta, V. 2017-12-01 Previous studies examining the response of magnetoelastic materials to shock waves have predominantly focused on applications involving pulsed power generation, with limited attention given to the actual wave propagation characteristics. This study provides detailed magnetic and mechanical measurements of magnetoelastic shock wave propagation and dispersion. Laser generated rarefacted shock waves exceeding 3 GPa with rise times of 10 ns were introduced to samples of the magnetoelastic material Galfenol. The resulting mechanical measurements reveal the evolution of the shock into a compressive acoustic front with lateral release waves. Importantly, the wave continues to disperse even after it has decayed into an acoustic wave, due in large part to magnetoelastic coupling. The magnetic data reveal predominantly shear wave mediated magnetoelastic coupling, and were also used to noninvasively measure the wave speed. The external magnetic field controlled a 30% increase in wave propagation speed, attributed to a 70% increase in average stiffness. Finally, magnetic signals propagating along the sample over 20× faster than the mechanical wave were measured, indicating these materials can act as passive antennas that transmit information in response to mechanical stimuli. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017EGUGA..1910542K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017EGUGA..1910542K">Tsunami mitigation - redistribution of energy</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Kadri, Usama 2017-04-01 Tsunamis are water waves caused by the displacement of a large volume of water, in the deep ocean or a large lake, following an earthquake, landslide, underwater explosion, meteorite impacts, or other violent geological events. On the coastline, the resulting waves evolve from unnoticeable to devastating, reaching heights of tens of meters and causing destruction of property and loss of life. Over 225,000 people were killed in the 2004 Indian Ocean tsunami alone. For many decades, scientists have been studying tsunami, and progress has been widely reported in connection with the causes (1), forecasting (2), and recovery (3). However, none of the studies ratifies the approach of a direct mitigation of tsunamis, with the exception of mitigation using submarine barriers (e.g. see Ref. (4)). In an attempt to open a discussion on direct mitigation, I examine the feasibility of redistributing the total energy of a very long surface ocean (gravity) wave over a larger space through nonlinear resonant interaction with two finely tuned acoustic-gravity waves (see Refs. (5-8)). Theoretically, while the energy input in the acoustic-gravity waves required for an effective interaction is comparable to that in a tsunami (i.e. impractically large), employing the proposed mitigation technique the initial tsunami amplitude could be reduced substantially resulting in a much milder impact at the coastline. Moreover, such a technique would allow for the harnessing of the tsunami's own energy. Practically, this mitigation technique requires the design of highly accurate acoustic-gravity wave frequency transmitters or modulators, which is a rather challenging ongoing engineering problem. References 1. E. Bryant, 2014. Tsunami: the underrated hazard. Springer, doi:10.1007/978-3-319- 06133-7. 2. V. V. Titov, F. I. Gonza`lez, E. N. Bernard, M. C. Eble, H. O. Mofjeld, J. C. Newman, A. J. Venturato, 2005. Real-Time Tsunami Forecasting: Challenges and Solutions. Nat. Hazards 35:41-58, doi:10 </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016OcMod.107...14P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016OcMod.107...14P">Lattice Boltzmann approach for hydro-acoustic waves generated by tsunamigenic sea bottom displacement</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Prestininzi, P.; Abdolali, A.; Montessori, A.; Kirby, J. T.; La Rocca, Michele 2016-11-01 Tsunami waves are generated by sea bottom failures, landslides and faults. The concurrent generation of hydro-acoustic waves (HAW), which travel much faster than the tsunami, has received much attention, motivated by their possible exploitation as precursors of tsunamis. This feature makes the detection of HAW particularly well-suited for building an early-warning system. Accuracy and efficiency of the modeling approaches for HAW thus play a pivotal role in the design of such systems. Here, we present a Lattice Boltzmann Method (LBM) for the generation and propagation of HAW resulting from tsunamigenic ground motions and verify it against commonly employed modeling solutions. LBM is well known for providing fast and accurate solutions to both hydrodynamics and acoustics problems, thus it naturally becomes a candidate as a comprehensive computational tool for modeling generation and propagation of HAW. </li> <li> <a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70109244','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70109244">Tsunami forecast by joint inversion of real-time tsunami waveforms and seismic of GPS data: application to the Tohoku 2011 tsunami</a> <a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a> Yong, Wei; Newman, Andrew V.; Hayes, Gavin P.; Titov, Vasily V.; Tang, Liujuan 2014-01-01 Correctly characterizing tsunami source generation is the most critical component of modern tsunami forecasting. Although difficult to quantify directly, a tsunami source can be modeled via different methods using a variety of measurements from deep-ocean tsunameters, seismometers, GPS, and other advanced instruments, some of which in or near real time. Here we assess the performance of different source models for the destructive 11 March 2011 Japan tsunami using model–data comparison for the generation, propagation, and inundation in the near field of Japan. This comparative study of tsunami source models addresses the advantages and limitations of different real-time measurements with potential use in early tsunami warning in the near and far field. The study highlights the critical role of deep-ocean tsunami measurements and rapid validation of the approximate tsunami source for high-quality forecasting. We show that these tsunami measurements are compatible with other real-time geodetic data, and may provide more insightful understanding of tsunami generation from earthquakes, as well as from nonseismic processes such as submarine landslide failures. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2008AGUSM.U54A..02A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2008AGUSM.U54A..02A">Tsunami Hazard in the Algerian Coastline</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Amir, L. A. 2008-05-01 . Generation and propagation of induced seismic waves were estimated with another program adapted from the swan code for the resolution of the hydrodynamic shallow water equations. The results obtained will be firstly presented. Then, based on seismic waves travel times and run up height values, a large discussion will focus on the tsunami alert program for cities marked by fast urban development. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016NHESS..16.1239O','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016NHESS..16.1239O">Tsunami hazard potential for the equatorial southwestern Pacific atolls of Tokelau from scenario-based simulations</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Orpin, Alan R.; Rickard, Graham J.; Gerring, Peter K.; Lamarche, Geoffroy 2016-05-01 Devastating tsunami over the last decade have significantly heightened awareness of the potential consequences and vulnerability of low-lying Pacific islands and coastal regions. Our appraisal of the potential tsunami hazard for the atolls of the Tokelau Islands is based on a tsunami source-propagation-inundation model using Gerris Flow Solver, adapted from the companion study by Lamarche et al. (2015) for the islands of Wallis and Futuna. We assess whether there is potential for tsunami flooding on any of the village islets from a selection of 14 earthquake-source experiments. These earthquake sources are primarily based on the largest Pacific earthquakes of Mw ≥ 8.1 since 1950 and other large credible sources of tsunami that may impact Tokelau. Earthquake-source location and moment magnitude are related to tsunami-wave amplitudes and tsunami flood depths simulated for each of the three atolls of Tokelau. This approach yields instructive results for a community advisory but is not intended to be fully deterministic. Rather, the underlying aim is to identify credible sources that present the greatest potential to trigger an emergency response. Results from our modelling show that wave fields are channelled by the bathymetry of the Pacific basin in such a way that the swathes of the highest waves sweep immediately northeast of the Tokelau Islands. Our limited simulations suggest that trans-Pacific tsunami from distant earthquake sources to the north of Tokelau pose the most significant inundation threat. In particular, our assumed worst-case scenario for the Kuril Trench generated maximum modelled-wave amplitudes in excess of 1 m, which may last a few hours and include several wave trains. Other sources can impact specific sectors of the atolls, particularly distant earthquakes from Chile and Peru, and regional earthquake sources to the south. Flooding is dependent on the wave orientation and direct alignment to the incoming tsunami. Our "worst-case" tsunami </li> <li> <a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/20481860','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/20481860">Inward propagating chemical waves in Taylor vortices.</a> <a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a> Thompson, Barnaby W; Novak, Jan; Wilson, Mark C T; Britton, Melanie M; Taylor, Annette F 2010-04-01 Advection-reaction-diffusion (ARD) waves in the Belousov-Zhabotinsky reaction in steady Taylor-Couette vortices have been visualized using magnetic-resonance imaging and simulated using an adapted Oregonator model. We show how propagating wave behavior depends on the ratio of advective, chemical and diffusive time scales. In simulations, inward propagating spiral flamelets are observed at high Damköhler number (Da). At low Da, the reaction distributes itself over several vortices and then propagates inwards as contracting ring pulses--also observed experimentally. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015EGUGA..17..422K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015EGUGA..17..422K">Mathematics of tsunami: modelling and identification</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Krivorotko, Olga; Kabanikhin, Sergey 2015-04-01 Tsunami (long waves in the deep water) motion caused by underwater earthquakes is described by shallow water equations ( { ηtt = div (gH (x,y)-gradη), (x,y) ∈ Ω, t ∈ (0,T ); η|t=0 = q(x,y), ηt|t=0 = 0, (x,y) ∈ Ω. ( (1) Bottom relief H(x,y) characteristics and the initial perturbation data (a tsunami source q(x,y)) are required for the direct simulation of tsunamis. The main difficulty problem of tsunami modelling is a very big size of the computational domain (Ω = 500 × 1000 kilometres in space and about one hour computational time T for one meter of initial perturbation amplitude max|q|). The calculation of the function η(x,y,t) of three variables in Ω × (0,T) requires large computing resources. We construct a new algorithm to solve numerically the problem of determining the moving tsunami wave height S(x,y) which is based on kinematic-type approach and analytical representation of fundamental solution. Proposed algorithm of determining the function of two variables S(x,y) reduces the number of operations in 1.5 times than solving problem (1). If all functions does not depend on the variable y (one dimensional case), then the moving tsunami wave height satisfies of the well-known Airy-Green formula: S(x) = S(0)° --- 4H (0)/H (x). The problem of identification parameters of a tsunami source using additional measurements of a passing wave is called inverse tsunami problem. We investigate two different inverse problems of determining a tsunami source q(x,y) using two different additional data: Deep-ocean Assessment and Reporting of Tsunamis (DART) measurements and satellite altimeters wave-form images. These problems are severely ill-posed. The main idea consists of combination of two measured data to reconstruct the source parameters. We apply regularization techniques to control the degree of ill-posedness such as Fourier expansion, truncated singular value decomposition, numerical regularization. The algorithm of selecting the truncated number of </li> <li> <a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/1418915-propagation-dispersion-shock-waves-magnetoelastic-materials','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/1418915-propagation-dispersion-shock-waves-magnetoelastic-materials">Propagation and dispersion of shock waves in magnetoelastic materials</a> <a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a> Crum, R. S.; Domann, J. P.; Carman, G. P. Previous studies examining the response of magnetoelastic materials to shock waves have predominantly focused on applications involving pulsed power generation, with limited attention given to the actual wave propagation characteristics. This study provides detailed magnetic and mechanical measurements of magnetoelastic shock wave propagation and dispersion. Laser generated rarefacted shock waves exceeding 3 GPa with rise times of 10 ns were introduced to samples of the magnetoelastic material Galfenol. The resulting mechanical measurements reveal the evolution of the shock into a compressive acoustic front with lateral release waves. Importantly, the wave continues to disperse even after it has decayed into anmore » acoustic wave, due in large part to magnetoelastic coupling. The magnetic data reveal predominantly shear wave mediated magnetoelastic coupling, and were also used to noninvasively measure the wave speed. The external magnetic field controlled a 30% increase in wave propagation speed, attributed to a 70% increase in average stiffness. Lastly, magnetic signals propagating along the sample over 20× faster than the mechanical wave were measured, indicating these materials can act as passive antennas that transmit information in response to mechanical stimuli.« less </li> <li> <a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/pages/biblio/1418915-propagation-dispersion-shock-waves-magnetoelastic-materials','SCIGOV-DOEP'); return false;" href="https://www.osti.gov/pages/biblio/1418915-propagation-dispersion-shock-waves-magnetoelastic-materials">Propagation and dispersion of shock waves in magnetoelastic materials</a> <a target="_blank" href="http://www.osti.gov/pages">DOE PAGES</a> Crum, R. S.; Domann, J. P.; Carman, G. P.; ... 2017-11-15 Previous studies examining the response of magnetoelastic materials to shock waves have predominantly focused on applications involving pulsed power generation, with limited attention given to the actual wave propagation characteristics. This study provides detailed magnetic and mechanical measurements of magnetoelastic shock wave propagation and dispersion. Laser generated rarefacted shock waves exceeding 3 GPa with rise times of 10 ns were introduced to samples of the magnetoelastic material Galfenol. The resulting mechanical measurements reveal the evolution of the shock into a compressive acoustic front with lateral release waves. Importantly, the wave continues to disperse even after it has decayed into anmore » acoustic wave, due in large part to magnetoelastic coupling. The magnetic data reveal predominantly shear wave mediated magnetoelastic coupling, and were also used to noninvasively measure the wave speed. The external magnetic field controlled a 30% increase in wave propagation speed, attributed to a 70% increase in average stiffness. Lastly, magnetic signals propagating along the sample over 20× faster than the mechanical wave were measured, indicating these materials can act as passive antennas that transmit information in response to mechanical stimuli.« less </li> <li> <a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70168678','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70168678">The Pacific tsunami warning system</a> <a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a> Pararas-Carayannis, G. 1986-01-01 The impact of tsunamis on human societies can be traced back in written history to 480 BC, when the Minoan civilization in the Eastern Mediterranean was wiped out by great tsunami waves generated by the volcanic explosion of the island of Santorin. In the Pacific Ocean where the majority of these waves have been generated, the historical record, although brief, shows tremendous destruction. In Japan which has one of the most populated coastal regions in the world and a long history of earthquake activity, tsunamis have destroyed entire coastal communities. There is also history of tsunami destruction in Alaska, in Hawaiian Islands, and in South America. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009AGUFMNH43C1352O','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009AGUFMNH43C1352O">Earthquakes & Tsunamis flirting with the Ionosphere: the Sumatra gossip !!</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Occhipinti, G.; Coïsson, P.; Rolland, L. M.; Lognonne, P. 2009-12-01 The December 26, 2004 Sumatra Earthquake and the related Indian Ocean Tsunami generated the largest remote sensing data-set observing natural hazards. The observations showed both, ground motion and ocean sea surface displacement, as well as the related strong ionospheric anomalies. Total electron content (TEC) perturbations have been observed on a global scale, using ground-based GPS receivers [DasGupta et al., 2006, Liu et al., 2006b] and dual-frequency altimeters (e.g., Jason-1 and Topex/Poseidon [Artru et al., 2005]); plasma velocity perturbation has been observed by Doppler soundings [Liu et al., 2006b, Occhipinti et al., 2009]. The observed perturbations may be characterized as two different waves: the first one is an atmospheric wave in the acoustic domain induced by propagation of Rayleigh waves on the Earth surface; the second one is a slower atmospheric wave in the gravity domain strongly coupled with the generated tsunami. Both waves are reproduced by our accurate modeling taking into account the earthquake/tsunami-neutral atmosphere coupling at the base of the atmosphere, as well as the neutral-plasma coupling in the overlying ionosphere [Occhipinti et al., 2006, 2006, 2009]. Here we present a review of the ionospheric observations related to the Sumatra event in the light of modeling to deeply investigate the coupling mechanism between Solid-Earth/Ocean/Atmosphere/Ionosphere. The matching between data and modeling opens new perspectives in the solid earth research as well as in the tsunami detection providing a new insight into the role of the remote sensing in the monitoring of natural hazard. [Artru et al., 2005] Geophys. J. Int., 160, 2005 [DasGupta et al., 2006] Earth Planet. Space, 35, 929-959. [Liu et al., 2006a] Geophys. Res. Lett., 33, L02103, 2006. [Liu et al., 2006b] J. Geophys. Res., 111, A05303. [Occhipinti et al., 2006] Geophys. Res. Lett., 33, L20104, 2006 [Occhipinti et al., 2008] Geophys. J. Int., 173, 3, 753-1135, 2008. [Occhipinti et </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017NHESS..17..641Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017NHESS..17..641Z">A numerical study of tsunami wave impact and run-up on coastal cliffs using a CIP-based model</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Zhao, Xizeng; Chen, Yong; Huang, Zhenhua; Hu, Zijun; Gao, Yangyang 2017-05-01 There is a general lack of understanding of tsunami wave interaction with complex geographies, especially the process of inundation. Numerical simulations are performed to understand the effects of several factors on tsunami wave impact and run-up in the presence of gentle submarine slopes and coastal cliffs, using an in-house code, a constrained interpolation profile (CIP)-based model. The model employs a high-order finite difference method, the CIP method, as the flow solver; utilizes a VOF-type method, the tangent of hyperbola for interface capturing/slope weighting (THINC/SW) scheme, to capture the free surface; and treats the solid boundary by an immersed boundary method. A series of incident waves are arranged to interact with varying coastal geographies. Numerical results are compared with experimental data and good agreement is obtained. The influences of gentle submarine slope, coastal cliff and incident wave height are discussed. It is found that the tsunami amplification factor varying with incident wave is affected by gradient of cliff slope, and the critical value is about 45°. The run-up on a toe-erosion cliff is smaller than that on a normal cliff. The run-up is also related to the length of a gentle submarine slope with a critical value of about 2.292 m in the present model for most cases. The impact pressure on the cliff is extremely large and concentrated, and the backflow effect is non-negligible. Results of our work are highly precise and helpful in inverting tsunami source and forecasting disaster. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016PApGe.173.3999S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016PApGe.173.3999S">Tsunami hazard assessment in the Hudson River Estuary based on dynamic tsunami-tide simulations</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Shelby, Michael; Grilli, Stéphan T.; Grilli, Annette R. 2016-12-01 -way coupling. Four levels of nested grids are used, from a 1 arc-min spherical coordinate grid in the deep ocean down to a 39-m Cartesian grid in the HRE. Bottom friction coefficients in the finer grids are calibrated for the tide to achieve the local spatially averaged MHW level at high tide in the HRE. Combined tsunami-tide simulations are then performed for four phases of the tide corresponding to each tsunami arriving at Sandy Hook (NJ): 1.5 h ahead, concurrent with, 1.5 h after, and 3 h after the local high tide. These simulations are forced along the offshore boundary of the third-level grid by linearly superposing time series of surface elevation and horizontal currents of the calibrated tide and each tsunami wave train; this is done in deep enough water for a linear superposition to be accurate. Combined tsunami-tide simulations are then performed with FUNWAVE-TVD in this and the finest nested grids. Results show that, for the 3 PMTs, depending on the tide phase, the dynamic simulations lead to no or to a slightly increased inundation in the HRE (by up to 0.15 m depending on location), and to larger currents than for the simulations over a static level; the CRT SMF proxy tsunami is the PMT leading to maximum inundation in the HRE. For all tide phases, nonlinear interactions between tide and tsunami currents modify the elevation, current, and celerity of tsunami wave trains, mostly in the shallower water areas of the HRE where bottom friction dominates, as compared to a linear superposition of wave elevations and currents. We note that, while dynamic simulations predict a slight increase in inundation, this increase may be on the same order as, or even less than sources of uncertainty in the modeling of tsunami sources, such as their initial water elevation, and in bottom friction and bathymetry used in tsunami grids. Nevertheless, results in this paper provide insight into the magnitude and spatial variability of tsunami propagation and impact in the complex inland </li> <li> <a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70021726','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70021726">Wave-propagation formulation of seismic response of multistory buildings</a> <a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a> Safak, E. 1999-01-01 This paper presents a discrete-time wave-propagation method to calculate the seismic response of multistory buildings, founded on layered soil media and subjected to vertically propagating shear waves. Buildings are modeled as an extension of the layered soil media by considering each story as another layer in the wave-propagation path. The seismic response is expressed in terms of wave travel times between the layers and wave reflection and transmission coefficients at layer interfaces. The method accounts for the filtering effects of the concentrated foundation and floor masses. Compared with commonly used vibration formulation, the wave-propagation formulation provides several advantages, including simplicity, improved accuracy, better representation of damping, the ability to incorporate the soil layers under the foundation, and providing better tools for identification and damage detection from seismic records. Examples are presented to show the versatility and the superiority of the method. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AIPC.1870d0009K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AIPC.1870d0009K">Modeling the mitigation effect of coastal forests on tsunami</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Kh'ng, Xin Yi; Teh, Su Yean; Koh, Hock Lye 2017-08-01 As we have learned from the 26 Dec 2004 mega Andaman tsunami that killed 250, 000 lives worldwide, tsunami is a devastating natural disaster that can cause severe impacts including immense loss of human lives and extensive destruction of properties. The wave energy can be dissipated by the presence of coastal mangrove forests, which provide some degree of protection against tsunami waves. On the other hand, costly artificial structures such as reinforced walls can substantially diminish the aesthetic value and may cause environmental problems. To quantify the effectiveness of coastal forests in mitigating tsunami waves, an in-house 2-D model TUNA-RP is developed and used to quantify the reduction in wave heights and velocities due to the presence of coastal forests. The degree of reduction varies significantly depending on forest flow-resistant properties such as vegetation characteristics, forest density and forest width. The ability of coastal forest in reducing tsunami wave heights along the west coast of Penang Island is quantified by means of model simulations. Comparison between measured tsunami wave heights for the 2004 Andaman tsunami and 2-D TUNA-RP model simulated values demonstrated good agreement. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018JPhCS.957a2005F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018JPhCS.957a2005F">Gravitational Waves Propagation through the Stochastic Background of Gravitational Waves</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Frajuca, C.; Bortoli, F. S.; Nakamoto, F. Y.; Santos, G. A. 2018-02-01 With the recent claim that gravitational waves were finally detected and with other efforts around the world for GWs detection, its is reasonable to imagine that the relic gravitational wave background could be detected in some time in the future and with such information gather some hints about the origin of the universe. But, it’s also be considered that gravity has self-interaction, with such assumption it’s reasonable to expect that these gravitational wave will interact with the relic or nonrelic GW background by scattering, for example. Such interaction should decrease the distance which such propagating waves could be detected The propagation of gravitational waves (GWs) is analyzed in an asymptotically de Sitter space by the perturbation expansion around Minkowski space using a scalar component. Using the case of de Sitter inflationary phase scenario, the perturbation propagates through a FRW background. The GW, using the actual value for the Hubble scale (Ho), has a damping factor with a very small valor for the size of the observational universe; the stochastic relic GW background is given by a dimensionless function of the frequency. In this work we analyze this same damping including the gravitational wave background due to astrophysical sources such background is 3 orders of magnitude bigger in some frequencies and produces a higher damping factor. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011GeoJI.187.1699O','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011GeoJI.187.1699O">An irregular lattice method for elastic wave propagation</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> O'Brien, Gareth S.; Bean, Christopher J. 2011-12-01 Lattice methods are a class of numerical scheme which represent a medium as a connection of interacting nodes or particles. In the case of modelling seismic wave propagation, the interaction term is determined from Hooke's Law including a bond-bending term. This approach has been shown to model isotropic seismic wave propagation in an elastic or viscoelastic medium by selecting the appropriate underlying lattice structure. To predetermine the material constants, this methodology has been restricted to regular grids, hexagonal or square in 2-D or cubic in 3-D. Here, we present a method for isotropic elastic wave propagation where we can remove this lattice restriction. The methodology is outlined and a relationship between the elastic material properties and an irregular lattice geometry are derived. The numerical method is compared with an analytical solution for wave propagation in an infinite homogeneous body along with comparing the method with a numerical solution for a layered elastic medium. The dispersion properties of this method are derived from a plane wave analysis showing the scheme is more dispersive than a regular lattice method. Therefore, the computational costs of using an irregular lattice are higher. However, by removing the regular lattice structure the anisotropic nature of fracture propagation in such methods can be removed. </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li class="active">13</li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> </div> <div id="page_14" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li class="active">14</li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="261"> <li> <a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70019856','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70019856">Propagation of seismic waves in tall buildings</a> <a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a> Safak, E. 1998-01-01 A discrete-time wave propagation formulation of the seismic response of tall buildings is introduced. The building is modeled as a layered medium, similar to a layered soil medium, and is subjected to vertically propagating seismic shear waves. Soil layers and the bedrock under the foundation are incorporated in the formulation as additional layers. Seismic response is expressed in terms of the wave travel times between the layers, and the wave reflection and transmission coefficients at the layer interfaces. The equations account for the frequency-dependent filtering effects of the foundation and floor masses. The calculation of seismic response is reduced to a pair of simple finite-difference equations for each layer, which can be solved recursively starting from the bedrock. Compared to the commonly used vibration formulation, the wave propagation formulation provides several advantages, including simplified calculations, better representation of damping, ability to account for the effects of the soil layers under the foundation, and better tools for identification and damage detection from seismic records. Examples presented show the versatility of the method. ?? 1998 John Wiley & Sons, Ltd. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2008AGUFMOS43D1340U','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2008AGUFMOS43D1340U">Solomon Islands 2007 Tsunami Near-Field Modeling and Source Earthquake Deformation</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Uslu, B.; Wei, Y.; Fritz, H.; Titov, V.; Chamberlin, C. 2008-12-01 The earthquake of 1 April 2007 left behind momentous footages of crust rupture and tsunami impact along the coastline of Solomon Islands (Fritz and Kalligeris, 2008; Taylor et al., 2008; McAdoo et al., 2008; PARI, 2008), while the undisturbed tsunami signals were also recorded at nearby deep-ocean tsunameters and coastal tide stations. These multi-dimensional measurements provide valuable datasets to tackle the challenging aspects at the tsunami source directly by inversion from tsunameter records in real time (available in a time frame of minutes), and its relationship with the seismic source derived either from the seismometer records (available in a time frame of hours or days) or from the crust rupture measurements (available in a time frame of months or years). The tsunami measurements in the near field, including the complex vertical crust motion and tsunami runup, are particularly critical to help interpreting the tsunami source. This study develops high-resolution inundation models for the Solomon Islands to compute the near-field tsunami impact. Using these models, this research compares the tsunameter-derived tsunami source with the seismic-derived earthquake sources from comprehensive perceptions, including vertical uplift and subsidence, tsunami runup heights and their distributional pattern among the islands, deep-ocean tsunameter measurements, and near- and far-field tide gauge records. The present study stresses the significance of the tsunami magnitude, source location, bathymetry and topography in accurately modeling the generation, propagation and inundation of the tsunami waves. This study highlights the accuracy and efficiency of the tsunameter-derived tsunami source in modeling the near-field tsunami impact. As the high- resolution models developed in this study will become part of NOAA's tsunami forecast system, these results also suggest expanding the system for potential applications in tsunami hazard assessment, search and rescue operations </li> <li> <a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19880015884','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19880015884">Linear and nonlinear acoustic wave propagation in the atmosphere</a> <a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a> Hariharan, S. I.; Yu, Ping 1988-01-01 The investigation of the acoustic wave propagation theory and numerical implementation for the situation of an isothermal atmosphere is described. A one-dimensional model to validate an asymptotic theory and a 3-D situation to relate to a realistic situation are considered. In addition, nonlinear wave propagation and the numerical treatment are included. It is known that the gravitational effects play a crucial role in the low frequency acoustic wave propagation. They propagate large distances and, as such, the numerical treatment of those problems become difficult in terms of posing boundary conditions which are valid for all frequencies. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018JGRA..123..587L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018JGRA..123..587L">One-Dimensional Full Wave Simulation of Equatorial Magnetosonic Wave Propagation in an Inhomogeneous Magnetosphere</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Liu, Xu; Chen, Lunjin; Yang, Lixia; Xia, Zhiyang; Malaspina, David M. 2018-01-01 The effect of the plasmapause on equatorially radially propagating fast magnetosonic (MS) waves in the Earth's dipole magnetic field is studied by using finite difference time domain method. We run 1-D simulation for three different density profiles: (1) no plasmapause, (2) with a plasmapause, and (3) with a plasmapause accompanied with fine-scale density irregularity. We find that (1) without plasmapause the radially inward propagating MS wave can reach ionosphere and continuously propagate to lower altitude if no damping mechanism is considered. The wave properties follow the cold plasma dispersion relation locally along its trajectory. (2) For simulation with a plasmapause with a scale length of 0.006 RE compared to wavelength, only a small fraction of the MS wave power is reflected by the plasmapause. WKB approximation is generally valid for such plasmapause. (3) The multiple fine-scale density irregularities near the outer edge of plasmapause can effectively block the MS wave propagation, resulting in a terminating boundary for MS waves near the plasmapause. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1998P%26SS...47..273S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1998P%26SS...47..273S">Low frequency wave propagation in a cold magnetized dusty plasma</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Sarkar, S.; Ghosh, S.; Khan, M. 1998-12-01 In this paper several characteristics of low frequency waves in a cold magnetized dusty plasma propagating parallel and perpendicular to the static background magnetic field have been investigated. In the case of parallel propagation the negatively charged dust particles resonate with the right circularly polarized (RCP) component of em waves when the wave frequency equals the dust cyclotron frequency. It has been shown that an RCP wave in dusty plasma consists of two branches and there exists a region where an RCP wave propagation is not possible. Dispersion relation, phase velocity and group velocity of RCP waves have been obtained and propagation characteristics have been shown graphically. Poynting flux and Faraday rotation angles have been calculated for both lower and upper branches of the RCP wave. It has been observed that sense of rotation of the plane of polarization of the RCP wave corresponding to two distinct branches are opposite. Finally, the effect of dust particles on the induced magnetization from the inverse Faraday effect (IFE) due to the interaction of low frequency propagating and standing em waves with dusty plasmas has been evaluated. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016EGUGA..18.9483V','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016EGUGA..18.9483V">Generation and Upper Atmospheric Propagation of Acoustic Gravity Waves according to Numerical Modeling and Radio Tomography</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Vorontsov, Artem; Andreeva, Elena; Nesterov, Ivan; Padokhin, Artem; Kurbatov, Grigory 2016-04-01 The acoustic-gravity waves (AGW) in the upper atmosphere and ionosphere can be generated by a variety of the phenomena in the near-Earth environment and atmosphere as well as by some perturbations of the Earth's ground or ocean surface. For instance, the role of the AGW sources can be played by the earthquakes, explosions, thermal heating, seisches, tsunami waves. We present the examples of AGWs excited by the tsunami waves traveling in the ocean, by seisches, and by ionospheric heating by the high-power radio wave. In the last case, the gravity waves are caused by the pulsed modulation of the heating wave. The AGW propagation in the upper atmosphere induces the variations and irregularities in the electron density distribution of the ionosphere, whose structure can be efficiently reconstructed by the method of the ionospheric radio tomography (RT) based on the data from the global navigational satellite systems (GNSS). The input data for RT diagnostics are composed of the 150/400 MHz radio signals from the low-orbiting (LO) satellites and 1.2-1.5 GHz radio signals from the high-orbiting (HO) satellites with their orbits at ~1000 and ~20000 km above the ground, respectively. These data enable ionospheric imaging on different spatiotemporal scales with different spatiotemporal resolution and coverage, which is suitable, inter alia, for tracking the waves and wave-like features in the ionosphere. In particular, we demonstrate the maps of the ionospheric responses to the tornado at Moore (Oklahoma, USA) of May 20, 2013, which are reconstructed from the HO data. We present the examples of LORT images containing the waves and wavelike disturbances associated with various sources (e.g., auroral precipitation and high-power heating of the ionosphere). We also discuss the results of modeling the AGW generation by the surface and volumetric sources. The millihertz AGW from these sources initiate the ionospheric perturbation with a typical scale of a few hundred km at the </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017NHESS..17..685K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017NHESS..17..685K">Stand-alone tsunami alarm equipment</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Katsumata, Akio; Hayashi, Yutaka; Miyaoka, Kazuki; Tsushima, Hiroaki; Baba, Toshitaka; Catalán, Patricio A.; Zelaya, Cecilia; Riquelme Vasquez, Felipe; Sanchez-Olavarria, Rodrigo; Barrientos, Sergio 2017-05-01 One of the quickest means of tsunami evacuation is transfer to higher ground soon after strong and long ground shaking. Ground shaking itself is a good initiator of the evacuation from disastrous tsunami. Longer period seismic waves are considered to be more correlated with the earthquake magnitude. We investigated the possible application of this to tsunami hazard alarm using single-site ground motion observation. Information from the mass media is sometimes unavailable due to power failure soon after a large earthquake. Even when an official alarm is available, multiple information sources of tsunami alert would help people become aware of the coming risk of a tsunami. Thus, a device that indicates risk of a tsunami without requiring other data would be helpful to those who should evacuate. Since the sensitivity of a low-cost MEMS (microelectromechanical systems) accelerometer is sufficient for this purpose, tsunami alarm equipment for home use may be easily realized. Amplitude of long-period (20 s cutoff) displacement was proposed as the threshold for the alarm based on empirical relationships among magnitude, tsunami height, hypocentral distance, and peak ground displacement of seismic waves. Application of this method to recent major earthquakes indicated that such equipment could effectively alert people to the possibility of tsunami. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014NHESS..14.1155O','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014NHESS..14.1155O">Tsunami hazard assessment in the southern Colombian Pacific basin and a proposal to regenerate a previous barrier island as protection</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Otero, L. J.; Restrepo, J. C.; Gonzalez, M. 2014-05-01 In this study, the tsunami hazard posed to 120 000 inhabitants of Tumaco (Colombia) is assessed, and an evaluation and analysis of regenerating the previous El Guano Island for tsunami protection is conducted. El Guano Island was a sandy barrier island in front of the city of Tumaco until its disappearance during the tsunami of 1979; the island is believed to have played a protective role, substantially reducing the scale of the disaster. The analysis is conducted by identifying seismotectonic parameters and focal mechanisms of tsunami generation in the area, determining seven potential generation sources, applying a numerical model for tsunami generation and propagation, and evaluating the effect of tsunamis on Tumaco. The results show that in the current situation, this area is vulnerable to impact and flooding by tsunamis originating nearby. El Guano Island was found to markedly reduce flood levels and the energy flux of tsunami waves in Tumaco during the 1979 tsunami. By reducing the risk of flooding due to tsunamis, the regeneration and morphological modification of El Guano Island would help to protect Tumaco. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013NHESD...1.1173O','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013NHESD...1.1173O">Tsunami hazard assessment in the southern Colombian Pacific Basin and a proposal to regenerate a previous barrier island as protection</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Otero, L. J.; Restrepo, J. C.; Gonzalez, M. 2013-04-01 In this study, the tsunami hazard posed to 120 000 inhabitants of Tumaco (Colombia) is assessed, and an evaluation and analysis of regenerating the previous El Guano Island for tsunami protection is conducted. El Guano Island was a sandy barrier island in front of the city of Tumaco until its disappearance during the tsunami of 1979; the island is believed to have played a protective role, substantially reducing the scale of the disaster. The analysis is conducted by identifying seismotectonic parameters and focal mechanisms of tsunami generation in the area, determining seven potential generation sources, applying a numerical model for tsunami generation and propagation, and evaluating the effect of tsunamis on Tumaco. The results show that in the current situation, this area is vulnerable to impact and flooding by tsunamis originating nearby. El Guano Island was found to markedly reduce flood levels and the energy flux of tsunami waves in Tumaco during the 1979 tsunami. To reduce the risk of flooding due to tsunamis, the regeneration and morphological modification of El Guano Island would help to protect Tumaco. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011AGUFM.S14A..03F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011AGUFM.S14A..03F">The Chile tsunami of 27 February 2010: Field survey and modeling</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Fritz, H. M.; Petroff, C. M.; Catalan, P. A.; Cienfuegos, R.; Winckler, P.; Kalligeris, N.; Weiss, R.; Meneses, G.; Valderas-Bermejo, C.; Barrientos, S. E.; Ebeling, C. W.; Papadopoulos, A.; Contreras, M.; Almar, R.; Dominguez, J.; Synolakis, C. 2011-12-01 between Caleta Chome and Punta Morguilla. More than 2 m vertical uplift were measured on Santa Maria Island. Tsunami propagation in the Pacific Ocean is simulated using the benchmarked tsunami model MOST (Titov and Gonzalez, 1997; Titov and Synolakis, 1998). For initial conditions the inversion model of Lorito et al. (2011) is utilized. The model results highlight the directivity of the highest tsunami waves towards Juan Fernández and Easter Island during the transoceanic propagation. The team interviewed numerous eyewitnesses and educated residents about tsunami hazards since community-based education and awareness programs are essential to save lives in locales at risk from locally generated tsunamis. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AGUFMNH21A3827C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AGUFMNH21A3827C">When is a Tsunami a Mega-Tsunami?</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Chague-Goff, C.; Goff, J. R.; Terry, J. P.; Goto, K. 2014-12-01 The 2004 Indian Ocean Tsunami is commonly called a mega-tsunami, and this attribute has also been linked to the 2011 Tohoku-oki tsunami. However, since this term was first coined in the early 1990's there have been very few attempts to define it. As such it has been applied in a rather arbitrary fashion to a number of tsunami characteristics, such as wave height or amplitude at both the source and at distant locations, run-up height, geographical extent and impact. The first use of the term is related to a tsunami generated by a large bolide impact and indeed it seems entirely appropriate that the term should be used for such rare events on geological timescales. However, probably as a result of media-driven hyperbole, scientists have used this term at least twice in the last decade, which is hardly a significant portion of the geological timescale. It therefore seems reasonable to suggest that these recent unexpectedly large events do not fall in the category of mega-tsunami but into a category of exceptional events within historical experience and local perspective. The use of the term mega-tsunami over the past 14 years is discussed and a definition is provided that marks the relative uniqueness of these events and a new term, appropriately Japanese in origin, namely that of souteigai-tsunami, is proposed. Examples of these tsunamis will be provided. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014NJPh...16c3012G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014NJPh...16c3012G">Stationary propagation of a wave segment along an inhomogeneous excitable stripe</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Gao, Xiang; Zhang, Hong; Zykov, Vladimir; Bodenschatz, Eberhard 2014-03-01 We report a numerical and theoretical study of an excitation wave propagating along an inhomogeneous stripe of an excitable medium. The stripe inhomogeneity is due to a jump of the propagation velocity in the direction transverse to the wave motion. Stationary propagating wave segments of rather complicated curved shapes are observed. We demonstrate that the stationary segment shape strongly depends on the initial conditions which are used to initiate the excitation wave. In a certain parameter range, the wave propagation is blocked at the inhomogeneity boundary, although the wave propagation is supported everywhere within the stripe. A free-boundary approach is applied to describe these phenomena which are important for a wide variety of applications from cardiology to information processing. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AGUFMNH23B..05K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AGUFMNH23B..05K">Real-time tsunami inundation forecasting and damage mapping towards enhancing tsunami disaster resiliency</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Koshimura, S.; Hino, R.; Ohta, Y.; Kobayashi, H.; Musa, A.; Murashima, Y. 2014-12-01 With use of modern computing power and advanced sensor networks, a project is underway to establish a new system of real-time tsunami inundation forecasting, damage estimation and mapping to enhance society's resilience in the aftermath of major tsunami disaster. The system consists of fusion of real-time crustal deformation monitoring/fault model estimation by Ohta et al. (2012), high-performance real-time tsunami propagation/inundation modeling with NEC's vector supercomputer SX-ACE, damage/loss estimation models (Koshimura et al., 2013), and geo-informatics. After a major (near field) earthquake is triggered, the first response of the system is to identify the tsunami source model by applying RAPiD Algorithm (Ohta et al., 2012) to observed RTK-GPS time series at GEONET sites in Japan. As performed in the data obtained during the 2011 Tohoku event, we assume less than 10 minutes as the acquisition time of the source model. Given the tsunami source, the system moves on to running tsunami propagation and inundation model which was optimized on the vector supercomputer SX-ACE to acquire the estimation of time series of tsunami at offshore/coastal tide gauges to determine tsunami travel and arrival time, extent of inundation zone, maximum flow depth distribution. The implemented tsunami numerical model is based on the non-linear shallow-water equations discretized by finite difference method. The merged bathymetry and topography grids are prepared with 10 m resolution to better estimate the tsunami inland penetration. Given the maximum flow depth distribution, the system performs GIS analysis to determine the numbers of exposed population and structures using census data, then estimates the numbers of potential death and damaged structures by applying tsunami fragility curve (Koshimura et al., 2013). Since the tsunami source model is determined, the model is supposed to complete the estimation within 10 minutes. The results are disseminated as mapping products to </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012NHESS..12.1855U','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012NHESS..12.1855U">Web-based Tsunami Early Warning System: a case study of the 2010 Kepulaunan Mentawai Earthquake and Tsunami</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Ulutas, E.; Inan, A.; Annunziato, A. 2012-06-01 This study analyzes the response of the Global Disasters Alerts and Coordination System (GDACS) in relation to a case study: the Kepulaunan Mentawai earthquake and related tsunami, which occurred on 25 October 2010. The GDACS, developed by the European Commission Joint Research Center, combines existing web-based disaster information management systems with the aim to alert the international community in case of major disasters. The tsunami simulation system is an integral part of the GDACS. In more detail, the study aims to assess the tsunami hazard on the Mentawai and Sumatra coasts: the tsunami heights and arrival times have been estimated employing three propagation models based on the long wave theory. The analysis was performed in three stages: (1) pre-calculated simulations by using the tsunami scenario database for that region, used by the GDACS system to estimate the alert level; (2) near-real-time simulated tsunami forecasts, automatically performed by the GDACS system whenever a new earthquake is detected by the seismological data providers; and (3) post-event tsunami calculations using GCMT (Global Centroid Moment Tensor) fault mechanism solutions proposed by US Geological Survey (USGS) for this event. The GDACS system estimates the alert level based on the first type of calculations and on that basis sends alert messages to its users; the second type of calculations is available within 30-40 min after the notification of the event but does not change the estimated alert level. The third type of calculations is performed to improve the initial estimations and to have a better understanding of the extent of the possible damage. The automatic alert level for the earthquake was given between Green and Orange Alert, which, in the logic of GDACS, means no need or moderate need of international humanitarian assistance; however, the earthquake generated 3 to 9 m tsunami run-up along southwestern coasts of the Pagai Islands where 431 people died. The post </li> <li> <a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3055284','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3055284">Evaluation of a wave-vector-frequency-domain method for nonlinear wave propagation</a> <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a> Jing, Yun; Tao, Molei; Clement, Greg T. 2011-01-01 A wave-vector-frequency-domain method is presented to describe one-directional forward or backward acoustic wave propagation in a nonlinear homogeneous medium. Starting from a frequency-domain representation of the second-order nonlinear acoustic wave equation, an implicit solution for the nonlinear term is proposed by employing the Green’s function. Its approximation, which is more suitable for numerical implementation, is used. An error study is carried out to test the efficiency of the model by comparing the results with the Fubini solution. It is shown that the error grows as the propagation distance and step-size increase. However, for the specific case tested, even at a step size as large as one wavelength, sufficient accuracy for plane-wave propagation is observed. A two-dimensional steered transducer problem is explored to verify the nonlinear acoustic field directional independence of the model. A three-dimensional single-element transducer problem is solved to verify the forward model by comparing it with an existing nonlinear wave propagation code. Finally, backward-projection behavior is examined. The sound field over a plane in an absorptive medium is backward projected to the source and compared with the initial field, where good agreement is observed. PMID:21302985 </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012EGUGA..14.4667M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012EGUGA..14.4667M">Rapid processing of data based on high-performance algorithms for solving inverse problems and 3D-simulation of the tsunami and earthquakes</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Marinin, I. V.; Kabanikhin, S. I.; Krivorotko, O. I.; Karas, A.; Khidasheli, D. G. 2012-04-01 We consider new techniques and methods for earthquake and tsunami related problems, particularly - inverse problems for the determination of tsunami source parameters, numerical simulation of long wave propagation in soil and water and tsunami risk estimations. In addition, we will touch upon the issue of database management and destruction scenario visualization. New approaches and strategies, as well as mathematical tools and software are to be shown. The long joint investigations by researchers of the Institute of Mathematical Geophysics and Computational Mathematics SB RAS and specialists from WAPMERR and Informap have produced special theoretical approaches, numerical methods, and software tsunami and earthquake modeling (modeling of propagation and run-up of tsunami waves on coastal areas), visualization, risk estimation of tsunami, and earthquakes. Algorithms are developed for the operational definition of the origin and forms of the tsunami source. The system TSS numerically simulates the source of tsunami and/or earthquakes and includes the possibility to solve the direct and the inverse problem. It becomes possible to involve advanced mathematical results to improve models and to increase the resolution of inverse problems. Via TSS one can construct maps of risks, the online scenario of disasters, estimation of potential damage to buildings and roads. One of the main tools for the numerical modeling is the finite volume method (FVM), which allows us to achieve stability with respect to possible input errors, as well as to achieve optimum computing speed. Our approach to the inverse problem of tsunami and earthquake determination is based on recent theoretical results concerning the Dirichlet problem for the wave equation. This problem is intrinsically ill-posed. We use the optimization approach to solve this problem and SVD-analysis to estimate the degree of ill-posedness and to find the quasi-solution. The software system we developed is intended to </li> <li> <a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26392617','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26392617">Source mechanisms of volcanic tsunamis.</a> <a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a> Paris, Raphaël 2015-10-28 Volcanic tsunamis are generated by a variety of mechanisms, including volcano-tectonic earthquakes, slope instabilities, pyroclastic flows, underwater explosions, shock waves and caldera collapse. In this review, we focus on the lessons that can be learnt from past events and address the influence of parameters such as volume flux of mass flows, explosion energy or duration of caldera collapse on tsunami generation. The diversity of waves in terms of amplitude, period, form, dispersion, etc. poses difficulties for integration and harmonization of sources to be used for numerical models and probabilistic tsunami hazard maps. In many cases, monitoring and warning of volcanic tsunamis remain challenging (further technical and scientific developments being necessary) and must be coupled with policies of population preparedness. © 2015 The Author(s). </li> <li> <a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/22561929','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/22561929">Common omissions and misconceptions of wave propagation in turbulence: discussion.</a> <a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a> Charnotskii, Mikhail 2012-05-01 This review paper addresses typical mistakes and omissions that involve theoretical research and modeling of optical propagation through atmospheric turbulence. We discuss the disregard of some general properties of narrow-angle propagation in refractive random media, the careless use of simplified models of turbulence, and omissions in the calculations of the second moment of the propagating wave. We also review some misconceptions regarding short-exposure imaging, propagation of polarized waves, and calculations of the scintillation index of the beam waves. © 2012 Optical Society of America </li> <li> <a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25632135','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25632135">Propagating waves can explain irregular neural dynamics.</a> <a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a> Keane, Adam; Gong, Pulin 2015-01-28 Cortical neurons in vivo fire quite irregularly. Previous studies about the origin of such irregular neural dynamics have given rise to two major models: a balanced excitation and inhibition model, and a model of highly synchronized synaptic inputs. To elucidate the network mechanisms underlying synchronized synaptic inputs and account for irregular neural dynamics, we investigate a spatially extended, conductance-based spiking neural network model. We show that propagating wave patterns with complex dynamics emerge from the network model. These waves sweep past neurons, to which they provide highly synchronized synaptic inputs. On the other hand, these patterns only emerge from the network with balanced excitation and inhibition; our model therefore reconciles the two major models of irregular neural dynamics. We further demonstrate that the collective dynamics of propagating wave patterns provides a mechanistic explanation for a range of irregular neural dynamics, including the variability of spike timing, slow firing rate fluctuations, and correlated membrane potential fluctuations. In addition, in our model, the distributions of synaptic conductance and membrane potential are non-Gaussian, consistent with recent experimental data obtained using whole-cell recordings. Our work therefore relates the propagating waves that have been widely observed in the brain to irregular neural dynamics. These results demonstrate that neural firing activity, although appearing highly disordered at the single-neuron level, can form dynamical coherent structures, such as propagating waves at the population level. Copyright © 2015 the authors 0270-6474/15/351591-15$15.00/0. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015SPIE.9674E..0LT','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015SPIE.9674E..0LT">A propagation method with adaptive mesh grid based on wave characteristics for wave optics simulation</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Tang, Qiuyan; Wang, Jing; Lv, Pin; Sun, Quan 2015-10-01 Propagation simulation method and choosing mesh grid are both very important to get the correct propagation results in wave optics simulation. A new angular spectrum propagation method with alterable mesh grid based on the traditional angular spectrum method and the direct FFT method is introduced. With this method, the sampling space after propagation is not limited to propagation methods no more, but freely alterable. However, choosing mesh grid on target board influences the validity of simulation results directly. So an adaptive mesh choosing method based on wave characteristics is proposed with the introduced propagation method. We can calculate appropriate mesh grids on target board to get satisfying results. And for complex initial wave field or propagation through inhomogeneous media, we can also calculate and set the mesh grid rationally according to above method. Finally, though comparing with theoretical results, it's shown that the simulation result with the proposed method coinciding with theory. And by comparing with the traditional angular spectrum method and the direct FFT method, it's known that the proposed method is able to adapt to a wider range of Fresnel number conditions. That is to say, the method can simulate propagation results efficiently and correctly with propagation distance of almost zero to infinity. So it can provide better support for more wave propagation applications such as atmospheric optics, laser propagation and so on. </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li class="active">14</li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> </div> <div id="page_15" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li class="active">15</li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="281"> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AGUFMNH52A..03O','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUFMNH52A..03O">From Sumatra 2004 to Today, through Tohoku-Oki 2011: what we learn about Tsunami detection by ionospheric sounding.</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Occhipinti, G.; Rolland, L.; Watada, S.; Makela, J. J.; Bablet, A.; Coisson, P.; Lognonne, P. H.; Hebert, H. 2016-12-01 The tsunamigenic Tohoku earthquake (2011) strongly affirms, after the 26 December 2004, the necessity to open new paradigms in oceanic monitoring. Detection of ionospheric anomalies following the Sumatra earthquake tsunami (Occhipinti et al. 2006) demonstrated that ionosphere is sensitive to earthquake and tsunami propagation: ground and oceanic vertical displacement induces acoustic-gravity waves propagating within the neutral atmosphere and detectable in the ionosphere. Observations supported by modelling proved that tsunamigenic ionospheric anomalies are deterministic and reproducible by numerical modeling (Occhipinti et al., 2008). To prove that the tsunami signature in the ionosphere is routinely detected we show perturbations of total electron content (TEC) measured by GPS and following tsunamigenic eartquakes from 2004 to 2011 (Rolland et al. 2010, Occhipinti et al., 2013), nominally, Sumatra (26 December, 2004 and 12 September, 2007), Chile (14 November, 2007), Samoa (29 September, 2009) and the Tohoku-Oki (11 Mars, 2011). Additionally, new exciting measurements in the far-field were performed by Airglow measurement in Hawaii: those measurements show the propagation of the IGWs induced by the Tohoku tsunami in the Pacific Ocean (Occhipinti et al., 2011), as well as by two new recent tsunamis: the Queen Charlotte (27 October, 2013, Mw 7,7) and Chili (16 September, 2015, Mw 8.2). The detection of those two new events strongly confirm the potential interest and perspective of the tsunami monitoring by airglow camera, ground-located or potentially onboard on satelites. Based on the observations close to the epicenter, mainly performed by GPS networks located in Sumatra, Chile and Japan, we highlight the TEC perturbation observed within the first hour after the seismic rupture (Occhipinti et al., 2013). This perturbation contains informations about the ground displacement, as well as the consequent sea surface displacement resulting in the tsunami. In this talk </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010EGUGA..1212827Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010EGUGA..1212827Z">Statistical Analysis of Tsunami Variability</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Zolezzi, Francesca; Del Giudice, Tania; Traverso, Chiara; Valfrè, Giulio; Poggi, Pamela; Parker, Eric J. 2010-05-01 The purpose of this paper was to investigate statistical variability of seismically generated tsunami impact. The specific goal of the work was to evaluate the variability in tsunami wave run-up due to uncertainty in fault rupture parameters (source effects) and to the effects of local bathymetry at an individual location (site effects). This knowledge is critical to development of methodologies for probabilistic tsunami hazard assessment. Two types of variability were considered: • Inter-event; • Intra-event. Generally, inter-event variability refers to the differences of tsunami run-up at a given location for a number of different earthquake events. The focus of the current study was to evaluate the variability of tsunami run-up at a given point for a given magnitude earthquake. In this case, the variability is expected to arise from lack of knowledge regarding the specific details of the fault rupture "source" parameters. As sufficient field observations are not available to resolve this question, numerical modelling was used to generate run-up data. A scenario magnitude 8 earthquake in the Hellenic Arc was modelled. This is similar to the event thought to have caused the infamous 1303 tsunami. The tsunami wave run-up was computed at 4020 locations along the Egyptian coast between longitudes 28.7° E and 33.8° E. Specific source parameters (e.g. fault rupture length and displacement) were varied, and the effects on wave height were determined. A Monte Carlo approach considering the statistical distribution of the underlying parameters was used to evaluate the variability in wave height at locations along the coast. The results were evaluated in terms of the coefficient of variation of the simulated wave run-up (standard deviation divided by mean value) for each location. The coefficient of variation along the coast was between 0.14 and 3.11, with an average value of 0.67. The variation was higher in areas of irregular coast. This level of variability is </li> <li> <a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19730006669&hterms=tsunami&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3Dtsunami','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19730006669&hterms=tsunami&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3Dtsunami">Tides and tsunamis</a> <a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a> Zetler, B. D. 1972-01-01 Although tides and tsunamis are both shallow water waves, it does not follow that they are equally amenable to an observational program using an orbiting altimeter on a satellite. A numerical feasibility investigation using a hypothetical satellite orbit, real tide observations, and sequentially increased levels of white noise has been conducted to study the degradation of the tidal harmonic constants caused by adding noise to the tide data. Tsunami waves, possibly a foot high and one hundred miles long, must be measured in individual orbits, thus requiring high relative resolution. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2005AGUFM.U11A0807F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2005AGUFM.U11A0807F">Tsunami Source Model of the 2004 Sumatra-Andaman Earthquake inferred from Tide Gauge and Satellite Data</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Fujii, Y.; Satake, K. 2005-12-01 The tsunami generation process of the 2004 Sumatra-Andaman earthquake were estimated from the tsunami waveforms recorded on tide gauges and sea surface heights captured by satellite altimetry measurements over the Indian Ocean. The earthquake (0:58:53, 26, Dec., 2004, UTC), the largest in the last 40 years, caused devastating tsunami damages to the countries around the Indian Ocean. One of the important questions is the source length; the aftershocks were distributed along the Sunda trench for 1000 to 1200 km, from off northwestern part of Sumatra island through Nicobar islands to Andaman island, while seismic wave analyses indicate much shorter source length (several hundred km). We used instrumental data of this tsunami, tide gauges and sea surface heights. Tide gauge data have been collected by Global Sea Level Observing System (GLOSS). We have also used another tide gauges data for tsunami simulation analysis. Tsunami propagation was captured as sea surface heights of Jason-1 satellite altimetry measurements over the Indian Ocean for the first time (Gower, 2005). We numerically compute tsunami propagation on actually bathymetry. ETOPO2 (Smith and Sandwell, 1997), the gridded data of global ocean depth from bathymetry soundings and satellite gravity data, are less reliable in the shallow ocean. To improve the accuracy, we have digitized the charts near coasts and merged the digitized data with the ETOPO2 data. The long-wave equation and the equation of motion were numerically solved by finite-difference method (Satake, 1995). As the initial condition, a static deformation of seafloor has been calculated using rectangular fault model (Okada, 1985). The source region is divided into 22 subfaults. We fixed the size and geometry of each subfault, and varied the slip amount and rise time (or slip duration) for each subfault, and rupture velocity. Tsunami waveforms or Greens functions for each subfault were calculated for the rise times of 3, 10, 30 and 60 minutes </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017EGUGA..19.1246Y','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017EGUGA..19.1246Y">Assessment of Efficiency and Performance in Tsunami Numerical Modeling with GPU</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Yalciner, Bora; Zaytsev, Andrey 2017-04-01 Non-linear shallow water equations (NSWE) are used to solve the propagation and coastal amplification of long waves and tsunamis. Leap Frog scheme of finite difference technique is one of the satisfactory numerical methods which is widely used in these problems. Tsunami numerical models are necessary for not only academic but also operational purposes which need faster and accurate solutions. Recent developments in information technology provide considerably faster numerical solutions in this respect and are becoming one of the crucial requirements. Tsunami numerical code NAMI DANCE uses finite difference numerical method to solve linear and non-linear forms of shallow water equations for long wave problems, specifically for tsunamis. In this study, the new code is structured for Graphical Processing Unit (GPU) using CUDA API. The new code is applied to different (analytical, experimental and field) benchmark problems of tsunamis for tests. One of those applications is 2011 Great East Japan tsunami which was instrumentally recorded on various types of gauges including tide and wave gauges and offshore GPS buoys cabled Ocean Bottom Pressure (OBP) gauges and DART buoys. The accuracy of the results are compared with the measurements and fairly well agreements are obtained. The efficiency and performance of the code is also compared with the version using multi-core Central Processing Unit (CPU). Dependence of simulation speed with GPU on linear or non-linear solutions is also investigated. One of the results is that the simulation speed is increased up to 75 times comparing to the process time in the computer using single 4/8 thread multi-core CPU. The results are presented with comparisons and discussions. Furthermore how multi-dimensional finite difference problems fits towards GPU architecture is also discussed. The research leading to this study has received funding from the European Union's Seventh Framework Programme (FP7/2007-2013) under grant agreement No </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AGUFMNH43B1853F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUFMNH43B1853F">2015 Volcanic Tsunami Earthquake near Torishima Island: Array analysis of ocean bottom pressure gauge records</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Fukao, Y.; Sugioka, H.; Ito, A.; Shiobara, H.; Sandanbata, O.; Watada, S.; Satake, K. 2016-12-01 An array of ocean bottom pressure gauges was deployed off east of Aogashima island of the Izu-Bonin arc from May 2014 to May 2015. The array consists of 10 ocean bottom pressure gauges using ParoScientific quartz resonators which can measure absolute water pressure at 7000m depth with nano-resolution. The array configures equilateral triangles with minimum and maximum lengths of 10 and 30km. This array recorded seismic and tsunami waves from the CLVD-type earthquake (M5.7) of May 02, 2015, that occurred near Torishima Island 100 km distant from the array. Comparison with records of ordinary thrust earthquakes with similar magnitudes at similar distances indicates that this event generated anomalously large tsunamis relative to seismic waves. We made an array analysis for the phase speed, propagating azimuth and travel time of tsunami wave in a frequency range 1-10 mHz, where the dispersion effect is significant. The results show excellent agreements with the frequency-dependent ray-tracing calculations. The tsunami trace apparently starts with positive onset (pressure increase) and reaches a maximum amplitude of about 200Pa (≈2cm in tsunami height). A closer inspection, however, shows a preceding negative small pulse (Fig. 1), suggesting that the seafloor deformation at the tsunami source consists of a central large uplift and a peripheral small depression. This mode of deformation is qualitatively consistent with a finite CLVD source uniformly shortened laterally and uniformly stretched vertically without volume change. The detection of weak initial motions is indebted to the array deployment of sensitive pressure gauges far away from coastal regions. The bandpass-filtered waveform is drastically different between the lower and higher frequency ranges. The waveform is single-peaked in the lower frequency range (<5 mHz) but is ringing in the higher frequency range (>5 mHz), corresponding to the tsunami spectrum that consists of the broad primary peak around 3.5 m </li> <li> <a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3677718','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3677718">Shear wave propagation in anisotropic soft tissues and gels</a> <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a> Namani, Ravi; Bayly, Philip V. 2013-01-01 The propagation of shear waves in soft tissue can be visualized by magnetic resonance elastography (MRE) [1] to characterize tissue mechanical properties. Dynamic deformation of brain tissue arising from shear wave propagation may underlie the pathology of blast-induced traumatic brain injury. White matter in the brain, like other biological materials, exhibits a transversely isotropic structure, due to the arrangement of parallel fibers. Appropriate mathematical models and well-characterized experimental systems are needed to understand wave propagation in these structures. In this paper we review the theory behind waves in anisotropic, soft materials, including small-amplitude waves superimposed on finite deformation of a nonlinear hyperelastic material. Some predictions of this theory are confirmed in experimental studies of a soft material with controlled anisotropy: magnetically-aligned fibrin gel. PMID:19963987 </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AGUFMOS21F..06C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AGUFMOS21F..06C">Wave energy converter effects on wave propagation: A sensitivity study in Monterey Bay, CA</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Chang, G.; Jones, C. A.; Roberts, J.; Magalen, J.; Ruehl, K.; Chartrand, C. 2014-12-01 The development of renewable offshore energy in the United States is growing rapidly and wave energy is one of the largest resources currently being evaluated. The deployment of wave energy converter (WEC) arrays required to harness this resource could feasibly number in the hundreds of individual devices. The WEC arrays have the potential to alter nearshore wave propagation and circulation patterns and ecosystem processes. As the industry progresses from pilot- to commercial-scale it is important to understand and quantify the effects of WECs on the natural nearshore processes that support a local, healthy ecosystem. To help accelerate the realization of commercial-scale wave power, predictive modeling tools have been developed and utilized to evaluate the likelihood of environmental impact. At present, direct measurements of the effects of different types of WEC arrays on nearshore wave propagation are not available; therefore wave model simulations provide the groundwork for investigations of the sensitivity of model results to prescribed WEC characteristics over a range of anticipated wave conditions. The present study incorporates a modified version of an industry standard wave modeling tool, SWAN (Simulating WAves Nearshore), to simulate wave propagation through a hypothetical WEC array deployment site on the California coast. The modified SWAN, referred to as SNL-SWAN, incorporates device-specific WEC power take-off characteristics to more accurately evaluate a WEC device's effects on wave propagation. The primary objectives were to investigate the effects of a range of WEC devices and device and array characteristics (e.g., device spacing, number of WECs in an array) on nearshore wave propagation using SNL-SWAN model simulations. Results showed that significant wave height was most sensitive to variations in WEC device type and size and the number of WEC devices in an array. Locations in the lee centerline of the arrays in each modeled scenario showed the </li> <li> <a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70028313','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70028313">Numerical simulation of tsunami generation by cold volcanic mass flows at Augustine Volcano, Alaska</a> <a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a> Waythomas, C.F.; Watts, P.; Walder, J.S. 2006-01-01 Many of the world's active volcanoes are situated on or near coastlines. During eruptions, diverse geophysical mass flows, including pyroclastic flows, debris avalanches, and lahars, can deliver large volumes of unconsolidated debris to the ocean in a short period of time and thereby generate tsunamis. Deposits of both hot and cold volcanic mass flows produced by eruptions of Aleutian arc volcanoes are exposed at many locations along the coastlines of the Bering Sea, North Pacific Ocean, and Cook Inlet, indicating that the flows entered the sea and in some cases may have initiated tsunamis. We evaluate the process of tsunami generation by cold granular subaerial volcanic mass flows using examples from Augustine Volcano in southern Cook Inlet. Augustine Volcano is the most historically active volcano in the Cook Inlet region, and future eruptions, should they lead to debris-avalanche formation and tsunami generation, could be hazardous to some coastal areas. Geological investigations at Augustine Volcano suggest that as many as 12-14 debris avalanches have reached the sea in the last 2000 years, and a debris avalanche emplaced during an A.D. 1883 eruption may have initiated a tsunami that was observed about 80 km east of the volcano at the village of English Bay (Nanwalek) on the coast of the southern Kenai Peninsula. Numerical simulation of mass-flow motion, tsunami generation, propagation, and inundation for Augustine Volcano indicate only modest wave generation by volcanic mass flows and localized wave effects. However, for east-directed mass flows entering Cook Inlet, tsunamis are capable of reaching the more populated coastlines of the southwestern Kenai Peninsula, where maximum water amplitudes of several meters are possible. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018SPIE10602E..0BA','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018SPIE10602E..0BA">Bulk-wave ultrasonic propagation imagers</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Abbas, Syed Haider; Lee, Jung-Ryul 2018-03-01 Laser-based ultrasound systems are described that utilize the ultrasonic bulk-wave sensing to detect the damages and flaws in the aerospace structures. These systems apply pulse-echo or through transmission methods to detect longitudinal through-the-thickness bulk-waves. These thermoelastic waves are generated using Q-switched laser and non-contact sensing is performed using a laser Doppler vibrometer (LDV). Laser-based raster scanning is performed by either twoaxis translation stage for linear-scanning or galvanometer-based laser mirror scanner for angular-scanning. In all ultrasonic propagation imagers, the ultrasonic data is captured and processed in real-time and the ultrasonic propagation can be visualized during scanning. The scanning speed can go up to 1.8 kHz for two-axis linear translation stage based B-UPIs and 10 kHz for galvanometer-based laser mirror scanners. In contrast with the other available ultrasound systems, these systems have the advantage of high-speed, non-contact, real-time, and non-destructive inspection. In this paper, the description of all bulk-wave ultrasonic imagers (B-UPIs) are presented and their advantages are discussed. Experiments are performed with these system on various structures to proof the integrity of their results. The C-scan results produced from non-dispersive, through-the-thickness, bulk-wave detection show good agreement in detection of structural variances and damage location in all inspected structures. These results show that bulk-wave UPIs can be used for in-situ NDE of engineering structures. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017EPJWC.14002023S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017EPJWC.14002023S">Wave propagation of spectral energy content in a granular chain</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Shrivastava, Rohit Kumar; Luding, Stefan 2017-06-01 A mechanical wave is propagation of vibration with transfer of energy and momentum. Understanding the spectral energy characteristics of a propagating wave through disordered granular media can assist in understanding the overall properties of wave propagation through inhomogeneous materials like soil. The study of these properties is aimed at modeling wave propagation for oil, mineral or gas exploration (seismic prospecting) or non-destructive testing of the internal structure of solids. The focus is on the total energy content of a pulse propagating through an idealized one-dimensional discrete particle system like a mass disordered granular chain, which allows understanding the energy attenuation due to disorder since it isolates the longitudinal P-wave from shear or rotational modes. It is observed from the signal that stronger disorder leads to faster attenuation of the signal. An ordered granular chain exhibits ballistic propagation of energy whereas, a disordered granular chain exhibits more diffusive like propagation, which eventually becomes localized at long time periods. For obtaining mean-field macroscopic/continuum properties, ensemble averaging has been used, however, such an ensemble averaged spectral energy response does not resolve multiple scattering, leading to loss of information, indicating the need for a different framework for micro-macro averaging. </li> <li> <a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70025111','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70025111">Theoretical analysis of tsunami generation by pyroclastic flows</a> <a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a> Watts, P.; Waythomas, C.F. 2003-01-01 Pyroclastic flows are a common product of explosive volcanism and have the potential to initiate tsunamis whenever thick, dense flows encounter bodies of water. We evaluate the process of tsunami generation by pyroclastic flow by decomposing the pyroclastic flow into two components, the dense underflow portion, which we term the pyroclastic debris flow, and the plume, which includes the surge and coignimbrite ash cloud parts of the flow. We consider five possible wave generation mechanisms. These mechanisms consist of steam explosion, pyroclastic debris flow, plume pressure, plume shear, and pressure impulse wave generation. Our theoretical analysis of tsunami generation by these mechanisms provides an estimate of tsunami features such as a characteristic wave amplitude and wavelength. We find that in most situations, tsunami generation is dominated by the pyroclastic debris flow component of a pyroclastic flow. This work presents information sufficient to construct tsunami sources for an arbitrary pyroclastic flow interacting with most bodies of water. Copyright 2003 by the American Geophysical Union. </li> <li> <a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70031901','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70031901">Implications of the 26 December 2004 Sumatra-Andaman earthquake on tsunami forecast and assessment models for great subduction-zone earthquakes</a> <a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a> Geist, Eric L.; Titov, Vasily V.; Arcas, Diego; Pollitz, Fred F.; Bilek, Susan L. 2007-01-01 Results from different tsunami forecasting and hazard assessment models are compared with observed tsunami wave heights from the 26 December 2004 Indian Ocean tsunami. Forecast models are based on initial earthquake information and are used to estimate tsunami wave heights during propagation. An empirical forecast relationship based only on seismic moment provides a close estimate to the observed mean regional and maximum local tsunami runup heights for the 2004 Indian Ocean tsunami but underestimates mean regional tsunami heights at azimuths in line with the tsunami beaming pattern (e.g., Sri Lanka, Thailand). Standard forecast models developed from subfault discretization of earthquake rupture, in which deep- ocean sea level observations are used to constrain slip, are also tested. Forecast models of this type use tsunami time-series measurements at points in the deep ocean. As a proxy for the 2004 Indian Ocean tsunami, a transect of deep-ocean tsunami amplitudes recorded by satellite altimetry is used to constrain slip along four subfaults of the M >9 Sumatra–Andaman earthquake. This proxy model performs well in comparison to observed tsunami wave heights, travel times, and inundation patterns at Banda Aceh. Hypothetical tsunami hazard assessments models based on end- member estimates for average slip and rupture length (Mw 9.0–9.3) are compared with tsunami observations. Using average slip (low end member) and rupture length (high end member) (Mw 9.14) consistent with many seismic, geodetic, and tsunami inversions adequately estimates tsunami runup in most regions, except the extreme runup in the western Aceh province. The high slip that occurred in the southern part of the rupture zone linked to runup in this location is a larger fluctuation than expected from standard stochastic slip models. In addition, excess moment release (∼9%) deduced from geodetic studies in comparison to seismic moment estimates may generate additional tsunami energy, if the </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010EGUGA..1212792C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010EGUGA..1212792C">Tsunami hazard assessment for the Azores archipelago: a historical review</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Cabral, Nuno; Ferreira, Teresa; Queiroz, Maria Gabriela 2010-05-01 The Azores islands due to its complex geographical and geodynamic setting are exposed to tsunamigenic events associated to different triggering mechanisms, local or distant. Since the settlement of the Azores, in the fifteenth century, there are several documents that relate coastal areas flooding episodes with unusually high waves which caused death and destruction. This work had as main objective the characterization of the different events that can be associated with tsunamigenic phenomena, registered in the archipelago. With this aim, it was collected diverse documentation like chronics, manuscripts, newspaper articles and magazines, scientific publications, and international databases available online. From all the studied tsunami events it was identified the occurrence of some teletsunamis, among which the most relevant was triggered by the 1st November 1755 Lisbon earthquake, with an epicenter SW of Portugal, which killed 6 people in Terceira island. It is also noted the teletsunami generated by the 1761 earthquake, located in the same region as the latest, and the one generated in 1929 by an earthquake-triggered submarine landslide in the Grand Banks of Newfoundland. From the local events, originated in the Azores, the most significant were the tsunamis triggered by 1757 and 1980 earthquakes, both associated with the Terceira Rift dynamics. In the first case the waves may also be due to earthquake-triggered. With respect to tsunamis triggered by sea cliffs landslides it is important to mention the 1847 Quebrada Nova and the 1980 Rocha Alta events, both located in the Flores Island. The 1847 event is the deadliest tsunami recorded in Azores since 10 people died in Flores and Corvo islands in result of the propagated wave. The developed studies improve knowledge of the tsunami sources that affected the Azores during its history, also revealing the importance of awareness about this natural phenomenon. The obtained results showed that the tsunami hazard in the </li> <li> <a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70036490','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70036490">Effects of fringing reefs on tsunami inundation: American Samoa</a> <a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a> Gelfenbaum, G.; Apotsos, A.; Stevens, A.W.; Jaffe, B. 2011-01-01 A numerical model of tsunami inundation, Delft3D, which has been validated for the 29 September 2009 tsunami in Tutuila, American Samoa, is used to better understand the impact of fringing coral reefs and embayments on tsunami wave heights, inundation distances, and velocities. The inundation model is used to explore the general conditions under which fringing reefs act as coastal buffers against incoming tsunamis. Of particular interest is the response of tsunamis to reefs of varying widths, depths, and roughness, as well as the effects of channels incised in the reef and the focusing effect of embayments. Model simulations for conditions similar to Tutuila, yet simplified to be uniform in the alongshore, suggest that for narrow reefs, less than about 200 m wide, the shoaling owing to shallow water depths over the fringing reef dominates, inducing greater wave heights onshore under some conditions and farther inundation inland. As the reef width increases, wave dissipation through bottom friction begins to dominate and the reef causes the tsunami wave heights to decrease and the tsunami to inundate less far inland. A sensitivity analysis suggests that coral reef roughness is important in determining the manner in which a fringing reef affects tsunami inundation. Smooth reefs are more likely to increase the onshore velocity within the tsunami compared to rough reefs. A larger velocity will likely result in an increased impact of the tsunami on structures and buildings. Simulations developed to explore 2D coastal morphology show that incised channels similar to those found around Tutuila, as well as coastal embayments, also affect tsunami inundation, allowing larger waves to penetrate farther inland. The largest effect is found for channels located within embayments, and for embayments that narrow landward. These simulations suggest that embayments that narrow landward, such as Fagafue Bay on the north side of Tutuila, and that have an incised deep channel, can </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009EGUGA..1112704K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009EGUGA..1112704K">Modelling tsunami inundation for risk analysis at the Andaman Sea Coast of Thailand</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Kaiser, G.; Kortenhaus, A. 2009-04-01 The mega-tsunami of Dec. 26, 2004 strongly impacted the Andaman Sea coast of Thailand and devastated coastal ecosystems as well as towns, settlements and tourism resorts. In addition to the tragic loss of many lives, the destruction or damage of life-supporting infrastructure, such as buildings, roads, water & power supply etc. caused high economic losses in the region. To mitigate future tsunami impacts there is a need to assess the tsunami hazard and vulnerability in flood prone areas at the Andaman Sea coast in order to determine the spatial distribution of risk and to develop risk management strategies. In the bilateral German-Thai project TRAIT research is performed on integrated risk assessment for the Provinces Phang Nga and Phuket in southern Thailand, including a hazard analysis, i.e. modelling tsunami propagation to the coast, tsunami wave breaking and inundation characteristics, as well as vulnerability analysis of the socio-economic and the ecological system in order to determine the scenario-based, specific risk for the region. In this presentation results of the hazard analysis and the inundation simulation are presented and discussed. Numerical modelling of tsunami propagation and inundation simulation is an inevitable tool for risk analysis, risk management and evacuation planning. While numerous investigations have been made to model tsunami wave generation and propagation in the Indian Ocean, there is still a lack in determining detailed inundation patterns, i.e. water depth and flow dynamics. However, for risk management and evacuation planning this knowledge is essential. As the accuracy of the inundation simulation is strongly depending on the available bathymetric and the topographic data, a multi-scale approach is chosen in this work. The ETOPO Global Relief Model as a bathymetric basis and the Shuttle Radar Topography Mission (SRTM90) have been widely applied in tsunami modelling approaches as these data are free and almost world </li> <li> <a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19770004172','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19770004172">Wave propagation in fiber composite laminates, part 2</a> <a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a> Daniel, I. M.; Liber, T. 1976-01-01 An experimental investigation was conducted to determine the wave propagation characteristics, transient strains and residual properties in unidirectional and angle-ply boron/epoxy and graphite/epoxy laminates impacted with silicone rubber projectiles at velocities up to 250 MS-1. The predominant wave is flexural, propagating at different velocities in different directions. In general, measured wave velocities were higher than theoretically predicted values. The amplitude of the in-plane wave is less than ten percent of that of the flexural wave. Peak strains and strain rates in the transverse to the (outer) fiber direction are much higher than those in the direction of the fibers. The dynamics of impact were also studied with high speed photography. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017EGUGA..1916874C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017EGUGA..1916874C">Tsunami Simulators in Physical Modelling - Concept to Practical Solutions</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Chandler, Ian; Allsop, William; Robinson, David; Rossetto, Tiziana; McGovern, David; Todd, David 2017-04-01 Whilst many researchers have conducted simple 'tsunami impact' studies, few engineering tools are available to assess the onshore impacts of tsunami, with no agreed methods available to predict loadings on coastal defences, buildings or related infrastructure. Most previous impact studies have relied upon unrealistic waveforms (solitary or dam-break waves and bores) rather than full-duration tsunami waves, or have used simplified models of nearshore and over-land flows. Over the last 10+ years, pneumatic Tsunami Simulators for the hydraulic laboratory have been developed into an exciting and versatile technology, allowing the forces of real-world tsunami to be reproduced and measured in a laboratory environment for the first time. These devices have been used to model generic elevated and N-wave tsunamis up to and over simple shorelines, and at example coastal defences and infrastructure. They have also reproduced full-duration tsunamis including Mercator 2004 and Tohoku 2011, both at 1:50 scale. Engineering scale models of these tsunamis have measured wave run-up on simple slopes, forces on idealised sea defences, pressures / forces on buildings, and scour at idealised buildings. This presentation will describe how these Tsunami Simulators work, demonstrate how they have generated tsunami waves longer than the facilities within which they operate, and will present research results from three generations of Tsunami Simulators. Highlights of direct importance to natural hazard modellers and coastal engineers include measurements of wave run-up levels, forces on single and multiple buildings and comparison with previous theoretical predictions. Multiple buildings have two malign effects. The density of buildings to flow area (blockage ratio) increases water depths and flow velocities in the 'streets'. But the increased building densities themselves also increase the cost of flow per unit area (both personal and monetary). The most recent study with the Tsunami </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2008AGUSM.U53A..05G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2008AGUSM.U53A..05G">Observations and Modeling of Environmental and Human Damages by the 2004 Indian Ocean tsunami</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Goto, K.; Imamura, F.; Koshimura, S.; Yanagisawa, H. 2008-05-01 On 26 December 2004, one of the largest tsunamis in human history (the 2004 Indian Ocean tsunami) struck coastal areas of countries surrounding the Indian Ocean, causing severe property damage and loss of life and causing us to think anew about the fearful consequences of a tsunami disaster. The tsunami devastated more than 10 countries around the ocean including Indonesia, Sri Lanka, India, and Thailand. Since its energy remains almost constant, the tsunami wave height grows tremendously in shallow water. It ranged in runups of ~48m on the western shore of Sumatra, ~18m in Thailand, and ~15m in Sri Lanka. The tsunami killed nearly 230,000 people, including visitors from foreign countries, resulting in great economic losses. The tsunami was also affected coastal environment at these countries and induced severe topographic change, and damages to the marine ecosystems as well as vegetations on land. Immediately following the tsunami, number of research teams has investigated damages of environment and human communities by tsunamis. Numerical analyses of tsunami propagation have also been carried out to understand the behavior and wave properties of tsunamis. However, there are few studies that focused on the integration of the field observations and numerical results, nevertheless that such analysis is critically important to evaluate the environmental and human damages by the tsunami. In this contribution, we first review damages to the environment and humans due to the 2004 Indian Ocean tsunami at Thailand, Indonesia, and Sri Lanka based on our field observations, and then we evaluate these damages based on high resolution numerical results. For example, we conducted field observation as well as high-resolution (17 m grid cells) numerical calculation for damages of corals (reef rocks) and mangroves at Pakarang Cape, Thailand. We found that hundreds of reef rocks were emplaced on the tidal bench, and 70 % of mangroves were destroyed at the cape. Our numerical </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017JSV...406...89L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017JSV...406...89L">Wave propagation characteristics of a magnetic granular chain</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Leng, Dingxin; Liu, Guijie; Sun, Lingyu; Wang, Xiaojie 2017-10-01 We investigate the wave propagation characteristics of a horizontal alignment of magnetic grains under a non-uniform magnetic field. The magnetic force of each grain is obtained using Maxwell's principle. The contact interaction of grains is based on Hertz potential. The effects of magnetic field strength on the dynamic responses of a granular chain under strong, intermediate, and weak amplitudes of incident impulses in comparison with static precompression force are studied. Different wave propagation modes induced by the magnetic field are observed. The applied field strength demonstrably reinforces the granular-position-dependent behaviors of decreasing amplitude and increasing wave propagation velocity. The magnetic field-induced features of a magnetic granular chain have potential applications in adaptive structures for shock attenuation. </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li class="active">15</li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> </div> <div id="page_16" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li class="active">16</li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="301"> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1994PhDT.......106B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1994PhDT.......106B">Magnetic Field Effects and Electromagnetic Wave Propagation in Highly Collisional Plasmas.</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Bozeman, Steven Paul The homogeneity and size of radio frequency (RF) and microwave driven plasmas are often limited by insufficient penetration of the electromagnetic radiation. To investigate increasing the skin depth of the radiation, we consider the propagation of electromagnetic waves in a weakly ionized plasma immersed in a steady magnetic field where the dominant collision processes are electron-neutral and ion-neutral collisions. Retaining both the electron and ion dynamics, we have adapted the theory for cold collisionless plasmas to include the effects of these collisions and obtained the dispersion relation at arbitrary frequency omega for plane waves propagating at arbitrary angles with respect to the magnetic field. We discuss in particular the cases of magnetic field enhanced wave penetration for parallel and perpendicular propagation, examining the experimental parameters which lead to electromagnetic wave propagation beyond the collisional skin depth. Our theory predicts that the most favorable scaling of skin depth with magnetic field occurs for waves propagating nearly parallel to B and for omega << Omega_{rm e} where Omega_{rm e} is the electron cyclotron frequency. The scaling is less favorable for propagation perpendicular to B, but the skin depth does increase for this case as well. Still, to achieve optimal wave penetration, we find that one must design the plasma configuration and antenna geometry so that one generates primarily the appropriate angles of propagation. We have measured plasma wave amplitudes and phases using an RF magnetic probe and densities using Stark line broadening. These measurements were performed in inductively coupled plasmas (ICP's) driven with a standard helical coil, a reverse turn (Stix) coil, and a flat spiral coil. Density measurements were also made in a microwave generated plasma. The RF magnetic probe measurements of wave propagation in a conventional ICP with wave propagation approximately perpendicular to B show an increase in </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018CMT...tmp...46Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018CMT...tmp...46Z">Wave propagation model of heat conduction and group speed</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Zhang, Long; Zhang, Xiaomin; Peng, Song 2018-03-01 In view of the finite relaxation model of non-Fourier's law, the Cattaneo and Vernotte (CV) model and Fourier's law are presented in this work for comparing wave propagation modes. Independent variable translation is applied to solve the partial differential equation. Results show that the general form of the time spatial distribution of temperature for the three media comprises two solutions: those corresponding to the positive and negative logarithmic heating rates. The former shows that a group of heat waves whose spatial distribution follows the exponential function law propagates at a group speed; the speed of propagation is related to the logarithmic heating rate. The total speed of all the possible heat waves can be combined to form the group speed of the wave propagation. The latter indicates that the spatial distribution of temperature, which follows the exponential function law, decays with time. These features show that propagation accelerates when heated and decelerates when cooled. For the model media that follow Fourier's law and correspond to the positive heat rate of heat conduction, the propagation mode is also considered the propagation of a group of heat waves because the group speed has no upper bound. For the finite relaxation model with non-Fourier media, the interval of group speed is bounded and the maximum speed can be obtained when the logarithmic heating rate is exactly the reciprocal of relaxation time. And for the CV model with a non-Fourier medium, the interval of group speed is also bounded and the maximum value can be obtained when the logarithmic heating rate is infinite. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016EGUGA..18.6352K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016EGUGA..18.6352K">Wave Propagation in Bimodular Geomaterials</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Kuznetsova, Maria; Pasternak, Elena; Dyskin, Arcady; Pelinovsky, Efim 2016-04-01 Observations and laboratory experiments show that fragmented or layered geomaterials have the mechanical response dependent on the sign of the load. The most adequate model accounting for this effect is the theory of bimodular (bilinear) elasticity - a hyperelastic model with different elastic moduli for tension and compression. For most of geo- and structural materials (cohesionless soils, rocks, concrete, etc.) the difference between elastic moduli is such that their modulus in compression is considerably higher than that in tension. This feature has a profound effect on oscillations [1]; however, its effect on wave propagation has not been comprehensively investigated. It is believed that incorporation of bilinear elastic constitutive equations within theory of wave dynamics will bring a deeper insight to the study of mechanical behaviour of many geomaterials. The aim of this paper is to construct a mathematical model and develop analytical methods and numerical algorithms for analysing wave propagation in bimodular materials. Geophysical and exploration applications and applications in structural engineering are envisaged. The FEM modelling of wave propagation in a 1D semi-infinite bimodular material has been performed with the use of Marlow potential [2]. In the case of the initial load expressed by a harmonic pulse loading strong dependence on the pulse sign is observed: when tension is applied before compression, the phenomenon of disappearance of negative (compressive) strains takes place. References 1. Dyskin, A., Pasternak, E., & Pelinovsky, E. (2012). Periodic motions and resonances of impact oscillators. Journal of Sound and Vibration, 331(12), 2856-2873. 2. Marlow, R. S. (2008). A Second-Invariant Extension of the Marlow Model: Representing Tension and Compression Data Exactly. In ABAQUS Users' Conference. </li> <li> <a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/29047527','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/29047527">Invertible propagator for plane wave illumination of forward-scattering structures.</a> <a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a> Samelsohn, Gregory 2017-05-10 Propagation of directed waves in forward-scattering media is considered. It is assumed that the evolution of the wave field is governed by the standard parabolic wave equation. An efficient one-step momentum-space propagator, suitable for a tilted plane wave illumination of extended objects, is derived. It is expressed in terms of a propagation operator that transforms (the complex exponential of) a linogram of the illuminated object into a set of its diffraction patterns. The invertibility of the propagator is demonstrated, which permits a multiple-shot scatter correction to be performed, and makes the solution especially attractive for either projective or tomographic imaging. As an example, high-resolution tomograms are obtained in numerical simulations implemented for a synthetic phantom, with both refractive and absorptive inclusions. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016APS..DFDG26004M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016APS..DFDG26004M">Effect of fuel stratification on detonation wave propagation</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Masselot, Damien; Fievet, Romain; Raman, Venkat 2016-11-01 Rotating detonation engines (RDEs) form a class of pressure-gain combustion systems of higher efficiency compared to conventional gas turbine engines. One of the key features of the design is the injection system, as reactants need to be continuously provided to the detonation wave to sustain its propagation speed. As inhomogeneities in the reactant mixture can perturb the detonation wave front, premixed fuel jet injectors might seem like the most stable solution. However, this introduces the risk of the detonation wave propagating through the injector, causing catastrophic failure. On the other hand, non-premixed fuel injection will tend to quench the detonation wave near the injectors, reducing the likelihood of such failure. Still, the effects of such non-premixing and flow inhomogeneities ahead of a detonation wave have yet to be fully understood and are the object of this study. A 3D channel filled with O2 diluted in an inert gas with circular H2 injectors is simulated as a detonation wave propagates through the system. The impact of key parameters such as injector spacing, injector size, mixture composition and time variations will be discussed. PhD Candidate. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017EGUGA..1918772G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017EGUGA..1918772G">Comparison and Computational Performance of Tsunami-HySEA and MOST Models for the LANTEX 2013 scenario</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> González-Vida, Jose M.; Macías, Jorge; Mercado, Aurelio; Ortega, Sergio; Castro, Manuel J. 2017-04-01 Tsunami-HySEA model is used to simulate the Caribbean LANTEX 2013 scenario (LANTEX is the acronym for Large AtlaNtic Tsunami EXercise, which is carried out annually). The numerical simulation of the propagation and inundation phases, is performed with both models but using different mesh resolutions and nested meshes. Some comparisons with the MOST tsunami model available at the University of Puerto Rico (UPR) are made. Both models compare well for propagating tsunami waves in open sea, producing very similar results. In near-shore shallow waters, Tsunami-HySEA should be compared with the inundation version of MOST, since the propagation version of MOST is limited to deeper waters. Regarding the inundation phase, a 1 arc-sec (approximately 30 m) resolution mesh covering all of Puerto Rico, is used, and a three-level nested meshes technique implemented. In the inundation phase, larger differences between model results are observed. Nevertheless, the most striking difference resides in computational time; Tsunami-HySEA is coded using the advantages of GPU architecture, and can produce a 4 h simulation in a 60 arcsec resolution grid for the whole Caribbean Sea in less than 4 min with a single general-purpose GPU and as fast as 11 s with 32 general-purpose GPUs. In the inundation stage with nested meshes, approximately 8 hours of wall clock time is needed for a 2-h simulation in a single GPU (versus more than 2 days for the MOST inundation, running three different parts of the island—West, Center, East—at the same time due to memory limitations in MOST). When domain decomposition techniques are finally implemented by breaking up the computational domain into sub-domains and assigning a GPU to each sub-domain (multi-GPU Tsunami-HySEA version), we show that the wall clock time significantly decreases, allowing high-resolution inundation modelling in very short computational times, reducing, for example, if eight GPUs are used, the wall clock time to around 1 hour </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018JMMM..450....7L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018JMMM..450....7L">Homogeneous microwave field emitted propagating spin waves: Direct imaging and modeling</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Lohman, Mathis; Mozooni, Babak; McCord, Jeffrey 2018-03-01 We explore the generation of propagating dipolar spin waves by homogeneous magnetic field excitation in the proximity of the boundaries of magnetic microstructures. Domain wall motion, precessional dynamics, and propagating spin waves are directly imaged by time-resolved wide-field magneto-optical Kerr effect microscopy. The aspects of spin wave generation are clarified by micromagnetic calculations matching the experimental results. The region of dipolar spin wave formation is confined to the local resonant excitation due to non-uniform internal demagnetization fields at the edges of the patterned sample. Magnetic domain walls act as a border for the propagation of plane and low damped spin waves, thus restraining the spin waves within the individual magnetic domains. The findings are of significance for the general understanding of structural and configurational magnetic boundaries for the creation, the propagation, and elimination of spin waves. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFMNH13B..03Y','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFMNH13B..03Y">Hydraulic experiment on formation mechanism of tsunami deposit and verification of sediment transport model for tsunamis</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Yamamoto, A.; Takahashi, T.; Harada, K.; Sakuraba, M.; Nojima, K. 2017-12-01 An underestimation of the 2011 Tohoku tsunami caused serious damage in coastal area. Reconsideration for tsunami estimation needs knowledge of paleo tsunamis. The historical records of giant tsunamis are limited, because they had occurred infrequently. Tsunami deposits may include many of tsunami records and are expected to analyze paleo tsunamis. However, present research on tsunami deposits are not able to estimate the tsunami source and its magnitude. Furthermore, numerical models of tsunami and its sediment transport are also important. Takahashi et al. (1999) proposed a model of movable bed condition due to tsunamis, although it has some issues. Improvement of the model needs basic data on sediment transport and deposition. This study investigated the formation mechanism of tsunami deposit by hydraulic experiment using a two-dimensional water channel with slope. In a fixed bed condition experiment, velocity, water level and suspended load concentration were measured at many points. In a movable bed condition, effects of sand grains and bore wave on the deposit were examined. Yamamoto et al. (2016) showed deposition range varied with sand grain sizes. In addition, it is revealed that the range fluctuated by number of waves and wave period. The measurements of velocity and water level showed that flow was clearly different near shoreline and in run-up area. Large velocity by return flow was affected the amount of sand deposit near shoreline. When a cutoff wall was installed on the slope, the amount of sand deposit repeatedly increased and decreased. Especially, sand deposit increased where velocity decreased. Takahashi et al. (1999) adapted the proposed model into Kesennuma bay when the 1960 Chilean tsunami arrived, although the amount of sand transportation was underestimated. The cause of the underestimation is inferred that the velocity of this model was underestimated. A relationship between velocity and sediment transport has to be studied in detail, but </li> <li> <a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25786963','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25786963">Nonlinear guided wave propagation in prestressed plates.</a> <a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a> Pau, Annamaria; Lanza di Scalea, Francesco 2015-03-01 The measurement of stress in a structure presents considerable interest in many fields of engineering. In this paper, the diagnostic potential of nonlinear elastic guided waves in a prestressed plate is investigated. To do so, an analytical model is formulated accounting for different aspects involved in the phenomenon. The fact that the initial strains can be finite is considered using the Green Lagrange strain tensor, and initial and final configurations are not merged, as it would be assumed in the infinitesimal strain theory. Moreover, an appropriate third-order expression of the strain energy of the hyperelastic body is adopted to account for the material nonlinearities. The model obtained enables to investigate both the linearized case, which gives the variation of phase and group velocity as a function of the initial stress, and the nonlinear case, involving second-harmonic generation as a function of the initial state of stress. The analysis is limited to Rayleigh-Lamb waves propagating in a plate. Three cases of initial prestress are considered, including prestress in the direction of the wave propagation, prestress orthogonal to the direction of wave propagation, and plane isotropic stress. </li> <li> <a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19910070861&hterms=propagation+layering&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dpropagation%2Blayering','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19910070861&hterms=propagation+layering&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dpropagation%2Blayering">Wave propagation in composite media and material characterization</a> <a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a> Datta, Subhendu K.; Shah, A. H.; Karunasena, W. 1990-01-01 Characteristics of wave propagation in an undamaged composite medium are influenced by many factors, the most important of which are: microstructure, constituent properties, interfaces, residual stress fields, and ply lay-ups. Measurements of wave velocities, attenuation, and dispersion provide a powerful tool for nondestructive evaluation of these properties. Recent developments are reviewed for modeling ultrasonic wave propagation in fiber and particle-reinforced composite media. Additionally, some modeling studies are reviewed for the effects of interfaces and layering on attenuation and dispersion. These studies indicate possible ways of characterizing material properties by ultrasonic means. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AGUFMNH32B..04B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUFMNH32B..04B">Development of Physics and Control of Multiple Forcing Mechanisms for the Alaska Tsunami Forecast Model</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Bahng, B.; Whitmore, P.; Macpherson, K. A.; Knight, W. R. 2016-12-01 The Alaska Tsunami Forecast Model (ATFM) is a numerical model used to forecast propagation and inundation of tsunamis generated by earthquakes or other mechanisms in either the Pacific Ocean, Atlantic Ocean or Gulf of Mexico. At the U.S. National Tsunami Warning Center (NTWC), the use of the model has been mainly for tsunami pre-computation due to earthquakes. That is, results for hundreds of hypothetical events are computed before alerts, and are accessed and calibrated with observations during tsunamis to immediately produce forecasts. The model has also been used for tsunami hindcasting due to submarine landslides and due to atmospheric pressure jumps, but in a very case-specific and somewhat limited manner. ATFM uses the non-linear, depth-averaged, shallow-water equations of motion with multiply nested grids in two-way communications between domains of each parent-child pair as waves approach coastal waters. The shallow-water wave physics is readily applicable to all of the above tsunamis as well as to tides. Recently, the model has been expanded to include multiple forcing mechanisms in a systematic fashion, and to enhance the model physics for non-earthquake events.ATFM is now able to handle multiple source mechanisms, either individually or jointly, which include earthquake, submarine landslide, meteo-tsunami and tidal forcing. As for earthquakes, the source can be a single unit source or multiple, interacting source blocks. Horizontal slip contribution can be added to the sea-floor displacement. The model now includes submarine landslide physics, modeling the source either as a rigid slump, or as a viscous fluid. Additional shallow-water physics have been implemented for the viscous submarine landslides. With rigid slumping, any trajectory can be followed. As for meteo-tsunami, the forcing mechanism is capable of following any trajectory shape. Wind stress physics has also been implemented for the meteo-tsunami case, if required. As an example of multiple </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017E%26PSL.458..213L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017E%26PSL.458..213L">The effect of compliant prisms on subduction zone earthquakes and tsunamis</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Lotto, Gabriel C.; Dunham, Eric M.; Jeppson, Tamara N.; Tobin, Harold J. 2017-01-01 Earthquakes generate tsunamis by coseismically deforming the seafloor, and that deformation is largely controlled by the shallow rupture process. Therefore, in order to better understand how earthquakes generate tsunamis, one must consider the material structure and frictional properties of the shallowest part of the subduction zone, where ruptures often encounter compliant sedimentary prisms. Compliant prisms have been associated with enhanced shallow slip, seafloor deformation, and tsunami heights, particularly in the context of tsunami earthquakes. To rigorously quantify the role compliant prisms play in generating tsunamis, we perform a series of numerical simulations that directly couple dynamic rupture on a dipping thrust fault to the elastodynamic response of the Earth and the acoustic response of the ocean. Gravity is included in our simulations in the context of a linearized Eulerian description of the ocean, which allows us to model tsunami generation and propagation, including dispersion and related nonhydrostatic effects. Our simulations span a three-dimensional parameter space of prism size, prism compliance, and sub-prism friction - specifically, the rate-and-state parameter b - a that determines velocity-weakening or velocity-strengthening behavior. We find that compliant prisms generally slow rupture velocity and, for larger prisms, generate tsunamis more efficiently than subduction zones without prisms. In most but not all cases, larger, more compliant prisms cause greater amounts of shallow slip and larger tsunamis. Furthermore, shallow friction is also quite important in determining overall slip; increasing sub-prism b - a enhances slip everywhere along the fault. Counterintuitively, we find that in simulations with large prisms and velocity-strengthening friction at the base of the prism, increasing prism compliance reduces rather than enhances shallow slip and tsunami wave height. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017NHESS..17..693T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017NHESS..17..693T">Simulations of moving effect of coastal vegetation on tsunami damping</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Tsai, Ching-Piao; Chen, Ying-Chi; Octaviani Sihombing, Tri; Lin, Chang 2017-05-01 A coupled wave-vegetation simulation is presented for the moving effect of the coastal vegetation on tsunami wave height damping. The problem is idealized by solitary wave propagation on a group of emergent cylinders. The numerical model is based on general Reynolds-averaged Navier-Stokes equations with renormalization group turbulent closure model by using volume of fluid technique. The general moving object (GMO) model developed in computational fluid dynamics (CFD) code Flow-3D is applied to simulate the coupled motion of vegetation with wave dynamically. The damping of wave height and the turbulent kinetic energy along moving and stationary cylinders are discussed. The simulated results show that the damping of wave height and the turbulent kinetic energy by the moving cylinders are clearly less than by the stationary cylinders. The result implies that the wave decay by the coastal vegetation may be overestimated if the vegetation was represented as stationary state. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AGUFMNH31C3878R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AGUFMNH31C3878R">Inversion of tsunami height using ionospheric observations. The case of the 2012 Haida Gwaii tsunami</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Rakoto, V.; Lognonne, P. H.; Rolland, L. 2014-12-01 Large and moderate tsunamis generate atmospheric internal gravity waves that are detectable using ionospheric monitoring. Indeed tsunamis of height 2cm and more in open ocean were detected with GPS (Rolland et al. 2010). We present a new method to retrieve the tsunami height from GPS-derived Total Electron Content observations. We present the case of the Mw 7.8 Haida Gwaii earthquake that occured the 28 october 2012 offshore the Queen Charlotte island near the canadian west coast. This event created a moderate tsunami of 4cm offshore the Hawaii archipelago. Equipped with more than 50 receivers it was possible to image the tsunami-induced ionospheric perturbation. First, our forward model leading to the TEC perturbation follows three steps : (1) 3D modeling of the neutral atmosphere perturbation by summation of tsunami-induced gravity waves normal modes. (2) Coupling of the neutral atmosphere perturbation with the ionosphere to retrieve the electron density perturbation. (3) Integration of the electron density perturbation along each satellite-station ray path. Then we compare this results to the data acquired by the Hawaiian GPS network. Finally, we examine the possibility to invert the TEC data in order to retrieve the tsunami height and waveform. For this we investigate the link between the height of tsunamis and the perturbed TEC in the ionosphere. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017EGUGA..1919572S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017EGUGA..1919572S">Field experiments to determine wave propagation principles and mechanical properties of snow</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Simioni, Stephan; Gebhard, Felix; Dual, Jürg; Schweizer, Jürg 2017-04-01 To understand the release of snow avalanches by explosions one needs to know how acoustic waves travel above and within the snowpack. Hitherto, wave propagation was investigated in the laboratory with small samples or in the field in the shock wave region. We developed a measurement system and layout to derive wave attenuation in snow, wave speeds and elastic moduli on small-scale (1-2 m) field experiments to close the gap between the lab scale (0.1 m) and the scale of artificial release (10-100 m). We used solid explosives and hammer blows to create the load and accelerometers to measure the resulting wave within the snowpack. The strong attenuation we observed indicates that we measured the second longitudinal wave which propagates through the pore space. The wave speeds, however, corresponded to the speeds of the first longitudinal wave within the ice skeleton. The elastic moduli were high on the order of several tens of MPa for lower densities (150 kg m-3) and agreed well with earlier lab studies, in particular for the higher densities 250-400 kg m-3). However, the scatter was rather large as expected for in-situ experiments in the layered snow cover. In addition, we measured accelerations during propagation saw test experiments. The propagation of cracks during this type of snow instability test has mainly been studied by analysing the bending of the slab (due to the saw cut) using particle tracking velocimetry. We used the accelerometers to measure crack propagation speeds. The wave speeds were slightly higher for most experiments than reported previously. Furthermore, in some experiments, we encountered to different wave types with one propagating at a higher speed. This finding may be interpreted as the actual crack propagation and the settling of the weak layer (collapse wave). Our results show that field measurements of propagation properties are feasible and that crack propagation as observed during propagation saw tests may involve different processes </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AGUFMNH23A1851A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AGUFMNH23A1851A">Application of Seismic Array Processing to Tsunami Early Warning</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> An, C.; Meng, L. 2015-12-01 Tsunami wave predictions of the current tsunami warning systems rely on accurate earthquake source inversions of wave height data. They are of limited effectiveness for the near-field areas since the tsunami waves arrive before data are collected. Recent seismic and tsunami disasters have revealed the need for early warning to protect near-source coastal populations. In this work we developed the basis for a tsunami warning system based on rapid earthquake source characterisation through regional seismic array back-projections. We explored rapid earthquake source imaging using onshore dense seismic arrays located at regional distances on the order of 1000 km, which provides faster source images than conventional teleseismic back-projections. We implement this method in a simulated real-time environment, and analysed the 2011 Tohoku earthquake rupture with two clusters of Hi-net stations in Kyushu and Northern Hokkaido, and the 2014 Iquique event with the Earthscope USArray Transportable Array. The results yield reasonable estimates of rupture area, which is approximated by an ellipse and leads to the construction of simple slip models based on empirical scaling of the rupture area, seismic moment and average slip. The slip model is then used as the input of the tsunami simulation package COMCOT to predict the tsunami waves. In the example of the Tohoku event, the earthquake source model can be acquired within 6 minutes from the start of rupture and the simulation of tsunami waves takes less than 2 min, which could facilitate a timely tsunami warning. The predicted arrival time and wave amplitude reasonably fit observations. Based on this method, we propose to develop an automatic warning mechanism that provides rapid near-field warning for areas of high tsunami risk. The initial focus will be Japan, Pacific Northwest and Alaska, where dense seismic networks with the capability of real-time data telemetry and open data accessibility, such as the Japanese HiNet (>800 </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AGUFMNH43A1822G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUFMNH43A1822G">New Methodology for Computing Subaerial Landslide-Tsunamis: Application to the 2015 Tyndall Glacier Landslide, Alaska</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> George, D. L.; Iverson, R. M.; Cannon, C. M. 2016-12-01 Landslide-generated tsunamis pose significant hazards to coastal communities and infrastructure, but developing models to assess these hazards presents challenges beyond those confronted when modeling seismically generated tsunamis. We present a new methodology in which our depth-averaged two-phase model D-Claw (Proc. Roy. Soc. A, 2014, doi: 10.1098/rspa.2013.0819 and doi:10.1098/rspa.2013.0820) is used to simulate all stages of landslide dynamics and subsequent tsunami generation and propagation. D-Claw was developed to simulate landslides and debris-flows, but if granular solids are absent, then the D-Claw equations reduce to the shallow-water equations commonly used to model tsunamis. Because the model describes the evolution of solid and fluid volume fractions, it treats both landslides and tsunamis as special cases of a more general class of phenomena, and the landslide and tsunami can be simulated as a single-layer continuum with spatially and temporally evolving solid-grain concentrations. This seamless approach accommodates wave generation via mass displacement and longitudinal momentum transfer, the dominant mechanisms producing impulse waves when large subaerial landslides impact relatively shallow bodies of water. To test our methodology, we used D-Claw to model a large subaerial landslide and resulting tsunami that occurred on October, 17, 2015, in Taan Fjord near the terminus of Tyndall Glacier, Alaska. The estimated landslide volume derived from radiated long-period seismicity (C. Stark (2015), Abstract EP51D-08, AGU Fall Meeting) was about 70-80 million cubic meters. Guided by satellite imagery and this volume estimate, we inferred an approximate landslide basal slip surface, and we used material property values identical to those used in our previous modeling of the 2014 Oso, Washington, landslide. With these inputs the modeled tsunami inundation patterns on shorelines compare well with observations derived from satellite imagery. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015PhDT........76M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015PhDT........76M">Efficient techniques for wave-based sound propagation in interactive applications</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Mehra, Ravish Sound propagation techniques model the effect of the environment on sound waves and predict their behavior from point of emission at the source to the final point of arrival at the listener. Sound is a pressure wave produced by mechanical vibration of a surface that propagates through a medium such as air or water, and the problem of sound propagation can be formulated mathematically as a second-order partial differential equation called the wave equation. Accurate techniques based on solving the wave equation, also called the wave-based techniques, are too expensive computationally and memory-wise. Therefore, these techniques face many challenges in terms of their applicability in interactive applications including sound propagation in large environments, time-varying source and listener directivity, and high simulation cost for mid-frequencies. In this dissertation, we propose a set of efficient wave-based sound propagation techniques that solve these three challenges and enable the use of wave-based sound propagation in interactive applications. Firstly, we propose a novel equivalent source technique for interactive wave-based sound propagation in large scenes spanning hundreds of meters. It is based on the equivalent source theory used for solving radiation and scattering problems in acoustics and electromagnetics. Instead of using a volumetric or surface-based approach, this technique takes an object-centric approach to sound propagation. The proposed equivalent source technique generates realistic acoustic effects and takes orders of magnitude less runtime memory compared to prior wave-based techniques. Secondly, we present an efficient framework for handling time-varying source and listener directivity for interactive wave-based sound propagation. The source directivity is represented as a linear combination of elementary spherical harmonic sources. This spherical harmonic-based representation of source directivity can support analytical, data </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017SPIE10170E..2BP','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017SPIE10170E..2BP">High frequency guided wave propagation in monocrystalline silicon wafers</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Pizzolato, Marco; Masserey, Bernard; Robyr, Jean-Luc; Fromme, Paul 2017-04-01 Monocrystalline silicon wafers are widely used in the photovoltaic industry for solar panels with high conversion efficiency. The cutting process can introduce micro-cracks in the thin wafers and lead to varying thickness. High frequency guided ultrasonic waves are considered for the structural monitoring of the wafers. The anisotropy of the monocrystalline silicon leads to variations of the wave characteristics, depending on the propagation direction relative to the crystal orientation. Full three-dimensional Finite Element simulations of the guided wave propagation were conducted to visualize and quantify these effects for a line source. The phase velocity (slowness) and skew angle of the two fundamental Lamb wave modes (first anti-symmetric mode A0 and first symmetric mode S0) for varying propagation directions relative to the crystal orientation were measured experimentally. Selective mode excitation was achieved using a contact piezoelectric transducer with a custom-made wedge and holder to achieve a controlled contact pressure. The out-of-plane component of the guided wave propagation was measured using a noncontact laser interferometer. Good agreement was found with the simulation results and theoretical predictions based on nominal material properties of the silicon wafer. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19720022244','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19720022244">Holographic measurement of wave propagation in axi-symmetric shells</a> <a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a> Evensen, D. A.; Aprahamian, R.; Jacoby, J. L. 1972-01-01 The report deals with the use of pulsed, double-exposure holographic interferometry to record the propagation of transverse waves in thin-walled axi-symmetric shells. The report is subdivided into sections dealing with: (1) wave propagation in circular cylindrical shells, (2) wave propagation past cut-outs and stiffeners, and (3) wave propagation in conical shells. Several interferograms are presented herein which show the waves reflecting from the shell boundaries, from cut-outs, and from stiffening rings. The initial response of the shell was nearly axi-symmetric in all cases, but nonsymmetric modes soon appeared in the radial response. This result suggests that the axi-symmetric response of the shell may be dynamically unstable, and thus may preferentially excite certain circumferential harmonics through parametric excitation. Attempts were made throughout to correlate the experimental data with analysis. For the most part, good agreement between theory and experiment was obtained. Occasional differences were attributed primarily to simplifying assumptions used in the analysis. From the standpoint of engineering applications, it is clear that pulsed laser holography can be used to obtain quantitative engineering data. Areas of dynamic stress concentration, stress concentration factors, local anomalies, etc., can be readily determined by holography. </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li class="active">16</li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> </div> <div id="page_17" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li class="active">17</li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="321"> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFMNH23A0205S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFMNH23A0205S">How Perturbing Ocean Floor Disturbs Tsunami Waves</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Salaree, A.; Okal, E. 2017-12-01 Bathymetry maps play, perhaps the most crucial role in optimal tsunami simulations. Regardless of the simulation method, on one hand, it is desirable to include every detailed bathymetry feature in the simulation grids in order to predict tsunami amplitudes as accurately as possible, but on the other hand, large grids result in long simulation times. It is therefore, of interest to investigate a "sufficiency" level - if any - for the amount of details in bathymetry grids needed to reconstruct the most important features in tsunami simulations, as obtained from the actual bathymetry. In this context, we use a spherical harmonics series approach to decompose the bathymetry of the Pacific ocean into its components down to a resolution of 4 degrees (l=100) and create bathymetry grids by accumulating the resulting terms. We then use these grids to simulate the tsunami behavior from pure thrust events around the Pacific through the MOST algorithm (e.g. Titov & Synolakis, 1995; Titov & Synolakis, 1998). Our preliminary results reveal that one would only need to consider the sum of the first 40 coefficients (equivalent to a resolution of 1000 km) to reproduce the main components of the "real" results. This would result in simpler simulations, and potentially allowing for more efficient tsunami warning algorithms. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016EGUGA..1816602P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016EGUGA..1816602P">Seismic Shaking, Tsunami Wave Erosion And Generation of Seismo-Turbidites in the Ionian Sea</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Polonia, Alina; Nelson, Hans; Romano, Stefania; Vaiani, Stefano Claudio; Colizza, Ester; Gasparotto, Giorgio; Gasperini, Luca 2016-04-01 We are investigating the effects of earthquakes and tsunamis on the sedimentary record in the Ionian Sea through the analysis of turbidite deposits. A comparison between radiometric dating and historical earthquake catalogs suggests that recent turbidite generation is triggered by great earthquakes in the Calabrian and hellenic Arcs such as the AD 1908 Messina, AD 1693 Catania, AD 1169 Eastern Sicily and AD 365 Crete earthquakes. Textural, micropaleontological, geochemical and mineralogical signatures of the youngest three seismo-turbidites reveal cyclic patterns of sedimentary units. The basal stacked turbidites result from multiple slope failure sources as shown by different sedimentary structures as well as mineralogic, geochemical and micropaleontological compositions. The homogenite units, are graded muds deposited from the waning flows of the multiple turbidity currents that are trapped in the Ionian Sea confined basin. The uppermost unit is divided into two parts. The lower marine sourced laminated part without textural gradation, we interpret to result from seiching of the confined water mass that appears to be generated by earthquake ruptures combined with tsunami waves. The uppermost part we interpret as the tsunamite cap that is deposited by the slow settling suspension cloud created by tsunami wave backwash erosion of the shoreline and continental shelf. This tsunami process interpretation is based on the final textural gradation of the upper unit and a more continental source of the tsunami cap which includes C/N >10, the lack of abyssal foraminifera species wirth the local occurrence of inner shelf foraminifera. Seismic reflection images show that some deeper turbidite beds are very thick and marked by acoustic transparent homogenite mud layers at their top. Based on a high resolution study of the most recent of such megabeds (Homogenite/Augias turbidite, i.e. HAT), we show that it was triggered by the AD 365 Crete earthquake. Radiometric dating </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018PhPl...25c1901S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018PhPl...25c1901S">Wave propagation in and around negative-dielectric-constant discharge plasma</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Sakai, Osamu; Iwai, Akinori; Omura, Yoshiharu; Iio, Satoshi; Naito, Teruki 2018-03-01 The modes of wave propagation in media with a negative dielectric constant are not simple, unlike those for electromagnetic waves in media with a positive dielectric constant (where modes propagate inside the media with positive phase velocity since the refractive index is usually positive). Instead, they depend on the permeability sign, either positive or negative, and exhibit completely different features. In this report, we investigated a wave confined on the surface of a negative-dielectric-constant and a positive-permeability plasma medium for which the refractive index is imaginary. The propagation mode is similar to surface plasmon polaritons on the metal containing free electrons, but its frequency band is different due to the significant spatial gradient of the dielectric constant and a different pressure term. We also studied a wave with a negative dielectric constant and negative permeability, where the refractive index is negative. This wave can propagate inside the media, but its phase velocity is negative. It also shares similar qualities with waves in plasmonic devices with negative permeability in the photon range. </li> <li> <a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70148006','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70148006">Tsunamis: stochastic models of occurrence and generation mechanisms</a> <a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a> Geist, Eric L.; Oglesby, David D. 2014-01-01 The devastating consequences of the 2004 Indian Ocean and 2011 Japan tsunamis have led to increased research into many different aspects of the tsunami phenomenon. In this entry, we review research related to the observed complexity and uncertainty associated with tsunami generation, propagation, and occurrence described and analyzed using a variety of stochastic methods. In each case, seismogenic tsunamis are primarily considered. Stochastic models are developed from the physical theories that govern tsunami evolution combined with empirical models fitted to seismic and tsunami observations, as well as tsunami catalogs. These stochastic methods are key to providing probabilistic forecasts and hazard assessments for tsunamis. The stochastic methods described here are similar to those described for earthquakes (Vere-Jones 2013) and volcanoes (Bebbington 2013) in this encyclopedia. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AcMSn..31....1Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AcMSn..31....1Z">Modeling ocean wave propagation under sea ice covers</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Zhao, Xin; Shen, Hayley H.; Cheng, Sukun 2015-02-01 Operational ocean wave models need to work globally, yet current ocean wave models can only treat ice-covered regions crudely. The purpose of this paper is to provide a brief overview of ice effects on wave propagation and different research methodology used in studying these effects. Based on its proximity to land or sea, sea ice can be classified as: landfast ice zone, shear zone, and the marginal ice zone. All ice covers attenuate wave energy. Only long swells can penetrate deep into an ice cover. Being closest to open water, wave propagation in the marginal ice zone is the most complex to model. The physical appearance of sea ice in the marginal ice zone varies. Grease ice, pancake ice, brash ice, floe aggregates, and continuous ice sheet may be found in this zone at different times and locations. These types of ice are formed under different thermal-mechanical forcing. There are three classic models that describe wave propagation through an idealized ice cover: mass loading, thin elastic plate, and viscous layer models. From physical arguments we may conjecture that mass loading model is suitable for disjoint aggregates of ice floes much smaller than the wavelength, thin elastic plate model is suitable for a continuous ice sheet, and the viscous layer model is suitable for grease ice. For different sea ice types we may need different wave ice interaction models. A recently proposed viscoelastic model is able to synthesize all three classic models into one. Under suitable limiting conditions it converges to the three previous models. The complete theoretical framework for evaluating wave propagation through various ice covers need to be implemented in the operational ocean wave models. In this review, we introduce the sea ice types, previous wave ice interaction models, wave attenuation mechanisms, the methods to calculate wave reflection and transmission between different ice covers, and the effect of ice floe breaking on shaping the sea ice morphology </li> <li> <a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4525157','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4525157">Investigating Alfvénic wave propagation in coronal open-field regions</a> <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a> Morton, R. J.; Tomczyk, S.; Pinto, R. 2015-01-01 The physical mechanisms behind accelerating solar and stellar winds are a long-standing astrophysical mystery, although recent breakthroughs have come from models invoking the turbulent dissipation of Alfvén waves. The existence of Alfvén waves far from the Sun has been known since the 1970s, and recently the presence of ubiquitous Alfvénic waves throughout the solar atmosphere has been confirmed. However, the presence of atmospheric Alfvénic waves does not, alone, provide sufficient support for wave-based models; the existence of counter-propagating Alfvénic waves is crucial for the development of turbulence. Here, we demonstrate that counter-propagating Alfvénic waves exist in open coronal magnetic fields and reveal key observational insights into the details of their generation, reflection in the upper atmosphere and outward propagation into the solar wind. The results enhance our knowledge of Alfvénic wave propagation in the solar atmosphere, providing support and constraints for some of the recent Alfvén wave turbulence models. PMID:26213234 </li> <li> <a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/22590580-all-electrical-propagating-spin-wave-spectroscopy-broadband-wavevector-capability','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/22590580-all-electrical-propagating-spin-wave-spectroscopy-broadband-wavevector-capability">All electrical propagating spin wave spectroscopy with broadband wavevector capability</a> <a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a> Ciubotaru, F., E-mail: Florin.Ciubotaru@imec.be; KU Leuven, Departement Electrotechniek; Devolder, T. 2016-07-04 We developed an all electrical experiment to perform the broadband phase-resolved spectroscopy of propagating spin waves in micrometer sized thin magnetic stripes. The magnetostatic surface spin waves are excited and detected by scaled down to 125 nm wide inductive antennas, which award ultra broadband wavevector capability. The wavevector selection can be done by applying an excitation frequency above the ferromagnetic resonance. Wavevector demultiplexing is done at the spin wave detector thanks to the rotation of the spin wave phase upon propagation. A simple model accounts for the main features of the apparatus transfer functions. Our approach opens an avenue for themore » all electrical study of wavevector-dependent spin wave properties including dispersion spectra or non-reciprocal propagation.« less </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AGUFMNH41A1746A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUFMNH41A1746A">Tsunami Simulators in Physical Modelling Laboratories - From Concept to Proven Technique</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Allsop, W.; Chandler, I.; Rossetto, T.; McGovern, D.; Petrone, C.; Robinson, D. 2016-12-01 Before 2004, there was little public awareness around Indian Ocean coasts of the potential size and effects of tsunami. Even in 2011, the scale and extent of devastation by the Japan East Coast Tsunami was unexpected. There were very few engineering tools to assess onshore impacts of tsunami, so no agreement on robust methods to predict forces on coastal defences, buildings or related infrastructure. Modelling generally used substantial simplifications of either solitary waves (far too short durations) or dam break (unrealistic and/or uncontrolled wave forms).This presentation will describe research from EPI-centre, HYDRALAB IV, URBANWAVES and CRUST projects over the last 10 years that have developed and refined pneumatic Tsunami Simulators for the hydraulic laboratory. These unique devices have been used to model generic elevated and N-wave tsunamis up to and over simple shorelines, and at example defences. They have reproduced full-duration tsunamis including the Mercator trace from 2004 at 1:50 scale. Engineering scale models subjected to those tsunamis have measured wave run-up on simple slopes, forces on idealised sea defences and pressures / forces on buildings. This presentation will describe how these pneumatic Tsunami Simulators work, demonstrate how they have generated tsunami waves longer than the facility within which they operate, and will highlight research results from the three generations of Tsunami Simulator. Of direct relevance to engineers and modellers will be measurements of wave run-up levels and comparison with theoretical predictions. Recent measurements of forces on individual buildings have been generalized by separate experiments on buildings (up to 4 rows) which show that the greatest forces can act on the landward (not seaward) buildings. Continuing research in the 70m long 4m wide Fast Flow Facility on tsunami defence structures have also measured forces on buildings in the lee of a failed defence wall. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016EGUGA..1816169G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016EGUGA..1816169G">Performance Benchmarking of tsunami-HySEA for NTHMP Inundation Mapping Activities</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> González Vida, Jose M.; Castro, Manuel J.; Ortega Acosta, Sergio; Macías, Jorge; Millán, Alejandro 2016-04-01 According to the 2006 USA Tsunami Warning and Education Act, the tsunami inundation models used in the National Tsunami Hazard Mitigation Program (NTHMP) projects must be validated against some existing standard problems (see [OAR-PMEL-135], [Proceedings of the 2011 NTHMP Model Benchmarking Workshop]). These Benchmark Problems (BPs) cover different tsunami processes related to the inundation stage that the models must meet to achieve the NTHMP Mapping and Modeling Subcommittee (MMS) approval. Tsunami-HySEA solves the two-dimensional shallow-water system using a high-order path-conservative finite volume method. Values of h, qx and qy in each grid cell represent cell averages of the water depth and momentum components. The numerical scheme is conservative for both mass and momentum in flat bathymetries, and, in general, is mass preserving for arbitrary bathymetries. Tsunami-HySEA implements a PVM-type method that uses the fastest and the slowest wave speeds, similar to HLL method (see [Castro et al, 2012]). A general overview of the derivation of the high order methods is performed in [Castro et al, 2009]. For very big domains, Tsunami-HySEA also implements a two-step scheme similar to leap-frog for the propagation step and a second-order TVD-WAF flux-limiter scheme described in [de la Asunción et al, 2013] for the inundation step. Here, we present the results obtained by the model tsunami-HySEA against the proposed BPs. BP1: Solitary wave on a simple beach (non-breaking - analytic experiment). BP4: Solitary wave on a simple beach (breaking - laboratory experiment). BP6: Solitary wave on a conical island (laboratory experiment). BP7 - Runup on Monai Valley beach (laboratory experiment) and BP9: Okushiri Island tsunami (field experiment). The analysis and results of Tsunami-HySEA model are presented, concluding that the model meets the required objectives for all the BP proposed. References - Castro M.J., E.D. Fernández, A.M. Ferreiro, A. García, C. Parés (2009 </li> <li> <a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/17718331','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/17718331">Elastic guided wave propagation in electrical cables.</a> <a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a> Mateo, Carlos; Talavera, Juan A; Muñoz, Antonio 2007-07-01 This article analyzes the propagation modes of ultrasound waves inside an electrical cable in order to assess its behavior as an acoustic transmission channel. A theoretical model for propagation of elastic waves in electric power cables is presented. The power cables are represented as viscoelastic-layered cylindrical structures with a copper core and a dielectric cover. The model equations then have been applied and numerically resolved for this and other known structures such as solid and hollow cylinders. The results are compared with available data from other models. Several experimental measures were carried out and were compared with results from the numerical simulations. Experimental and simulated results showed a significant difference between elastic wave attenuation inside standard versus bare, low-voltage power cables. </li> <li> <a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/21405841','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/21405841">Spherical shock-wave propagation in three-dimensional granular packings.</a> <a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a> Xue, Kun; Bai, Chun-Hua 2011-02-01 We investigate numerically the spherical shock-wave propagation in an open dense granular packing perturbed by the sudden expansion of a spherical intruder in the interior of the pack, focusing on the correlation between geometrical fabrics and propagating properties. The measurements of the temporal and spatial variations in a variety of propagating properties define a consistent serrated wave substructure with characteristic length on the orders of particle diameters. Further inspection of particle packing reveals a well-defined particle layering that persists several particle diameters away from the intruder, although its dominant effects are only within one to two diameters. This interface-induced layering not only exactly coincides with the serrated wave profile, but also highlights the competition between two energy transmission mechanisms involving distinct transport speeds. The alternating dominances between these two mechanisms contribute to the nonlinear wave propagation on the particle scale. Moreover, the proliferation of intricate three-dimensional contact force networks suggests the anisotropic stress transmission, which is found to also arise from the localized packing structure in the vicinity of the intruder. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014PApGe.171.3175R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014PApGe.171.3175R">Introduction to "Tsunamis in the Pacific Ocean: 2011-2012"</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Rabinovich, Alexander B.; Borrero, Jose C.; Fritz, Hermann M. 2014-12-01 With this volume of the Pure and Applied Geophysics (PAGEOPH) topical issue "Tsunamis in the Pacific Ocean: 2011-2012", we are pleased to present 21 new papers discussing tsunami events occurring in this two-year span. Owing to the profound impact resulting from the unique crossover of a natural and nuclear disaster, research into the 11 March 2011 Tohoku, Japan earthquake and tsunami continues; here we present 12 papers related to this event. Three papers report on detailed field survey results and updated analyses of the wave dynamics based on these surveys. Two papers explore the effects of the Tohoku tsunami on the coast of Russia. Three papers discuss the tsunami source mechanism, and four papers deal with tsunami hydrodynamics in the far field or over the wider Pacific basin. In addition, a series of five papers presents studies of four new tsunami and earthquake events occurring over this time period. This includes tsunamis in El Salvador, the Philippines, Japan and the west coast of British Columbia, Canada. Finally, we present four new papers on tsunami science, including discussions on tsunami event duration, tsunami wave amplitude, tsunami energy and tsunami recurrence. </li> <li> <a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20150006003&hterms=foster&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAuthor-Name%26N%3D0%26No%3D40%26Ntt%3Dfoster','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20150006003&hterms=foster&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAuthor-Name%26N%3D0%26No%3D40%26Ntt%3Dfoster">Observing Tsunamis in the Ionosphere Using Ground Based GPS Measurements</a> <a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a> Galvan, D. A.; Komjathy, A.; Song, Y. Tony; Stephens, P.; Hickey, M. P.; Foster, J. 2011-01-01 Ground-based Global Positioning System (GPS) measurements of ionospheric Total Electron Content (TEC) show variations consistent with atmospheric internal gravity waves caused by ocean tsunamis following recent seismic events, including the Tohoku tsunami of March 11, 2011. We observe fluctuations correlated in time, space, and wave properties with this tsunami in TEC estimates processed using JPL's Global Ionospheric Mapping Software. These TEC estimates were band-pass filtered to remove ionospheric TEC variations with periods outside the typical range of internal gravity waves caused by tsunamis. Observable variations in TEC appear correlated with the Tohoku tsunami near the epicenter, at Hawaii, and near the west coast of North America. Disturbance magnitudes are 1-10% of the background TEC value. Observations near the epicenter are compared to estimates of expected tsunami-driven TEC variations produced by Embry Riddle Aeronautical University's Spectral Full Wave Model, an atmosphere-ionosphere coupling model, and found to be in good agreement. The potential exists to apply these detection techniques to real-time GPS TEC data, providing estimates of tsunami speed and amplitude that may be useful for future early warning systems. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013AGUFMNH43B1753M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013AGUFMNH43B1753M">Physical Modeling of Tsunamis Generated By 3D Deformable Landslides in Various Scenarios From Fjords to Conical Islands</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> McFall, B. C.; Fritz, H. M. 2013-12-01 Tsunamis generated by landslides and volcano flank collapse can be particularly devastative in the near field region due to locally high wave amplitudes and runup. The events of 1958 Lituya Bay, 1963 Vajont reservoir, 1980 Spirit Lake, 2002 Stromboli and 2010 Haiti demonstrate the danger of tsunamis generated by landslides or volcano flank collapses. Unfortunately critical field data from these events is lacking. Source and runup scenarios based on real world events are physically modeled using generalized Froude similarity in the three dimensional NEES tsunami wave basin at Oregon State University. A novel pneumatic landslide tsunami generator (LTG) was deployed to simulate landslides with varying geometry and kinematics. Two different materials are used to simulate landslides to study the granulometry effects: naturally rounded river gravel and cobble mixtures. The LTG consists of a sliding box filled with 1,350 kg of landslide material which is accelerated by means of four pneumatic pistons down a 2H:1V slope. The landslide is launched from the sliding box and continues to accelerate by gravitational forces up to velocities of 5 m/s. The landslide Froude number at impact with the water is in the range 1 <F <4. The bathymetric and topographic scenarios tested with the LTG are the basin-wide propagation and runup, fjord, curved headland fjord and a conical island setting representing a landslide off an island or a volcano flank collapse. Water surface elevations are recorded by an array of resistance wave gauges. The landslide deformation is measured from above and underwater camera recordings. The landslide deposit is measured on the basin floor with a multiple transducer acoustic array (MTA). Landslide surface reconstruction and kinematics are determined with a stereo particle image velocimetry (PIV) system. Wave runup is recorded with resistance wave gauges along the slope and verified with video image processing. The measured landslide and wave parameters are </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AGUFMIN32A..06B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUFMIN32A..06B">Seismogeodesy for rapid earthquake and tsunami characterization</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Bock, Y. 2016-12-01 Rapid estimation of earthquake magnitude and fault mechanism is critical for earthquake and tsunami warning systems. Traditionally, the monitoring of earthquakes and tsunamis has been based on seismic networks for estimating earthquake magnitude and slip, and tide gauges and deep-ocean buoys for direct measurement of tsunami waves. These methods are well developed for ocean basin-wide warnings but are not timely enough to protect vulnerable populations and infrastructure from the effects of local tsunamis, where waves may arrive within 15-30 minutes of earthquake onset time. Direct measurements of displacements by GPS networks at subduction zones allow for rapid magnitude and slip estimation in the near-source region, that are not affected by instrumental limitations and magnitude saturation experienced by local seismic networks. However, GPS displacements by themselves are too noisy for strict earthquake early warning (P-wave detection). Optimally combining high-rate GPS and seismic data (in particular, accelerometers that do not clip), referred to as seismogeodesy, provides a broadband instrument that does not clip in the near field, is impervious to magnitude saturation, and provides accurate real-time static and dynamic displacements and velocities in real time. Here we describe a NASA-funded effort to integrate GPS and seismogeodetic observations as part of NOAA's Tsunami Warning Centers in Alaska and Hawaii. It consists of a series of plug-in modules that allow for a hierarchy of rapid seismogeodetic products, including automatic P-wave picking, hypocenter estimation, S-wave prediction, magnitude scaling relationships based on P-wave amplitude (Pd) and peak ground displacement (PGD), finite-source CMT solutions and fault slip models as input for tsunami warnings and models. For the NOAA/NASA project, the modules are being integrated into an existing USGS Earthworm environment, currently limited to traditional seismic data. We are focused on a network of </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFMNH23A0203S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFMNH23A0203S">Estimation of the Characterized Tsunami Source Model considering the Complicated Shape of Tsunami Source by Using the observed waveforms of GPS Buoys in the Nankai Trough</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Seto, S.; Takahashi, T. 2017-12-01 In the 2011 Tohoku earthquake tsunami disaster, the delay of understanding damage situation increased the human damage. To solve this problem, it is important to search the severe damaged areas. The tsunami numerical modeling is useful to estimate damages and the accuracy of simulation depends on the tsunami source. Seto and Takahashi (2017) proposed a method to estimate the characterized tsunami source model by using the limited observed data of GPS buoys. The model consists of Large slip zone (LSZ), Super large slip zone (SLSZ) and background rupture zone (BZ) as the Cabinet Office, Government of Japan (below COGJ) reported after the Tohoku tsunami. At the beginning of this method, the rectangular fault model is assumed based on the seismic magnitude and hypocenter reported right after an earthquake. By using the fault model, tsunami propagation is simulated numerically, and the fault model is improved after comparing the computed data with the observed data repeatedly. In the comparison, correlation coefficient and regression coefficient are used as indexes. They are calculated with the observed and the computed tsunami wave profiles. This repetition is conducted to get the two coefficients close to 1.0, which makes the precise of the fault model higher. However, it was indicated as the improvement that the model did not examine a complicated shape of tsunami source. In this study, we proposed an improved model to examine the complicated shape. COGJ(2012) assumed that possible tsunami source region in the Nankai trough consisted of the several thousands small faults. And, we use these small faults to estimate the targeted tsunami source in this model. Therefore, we can estimate the complicated tsunami source by using these small faults. The estimation of BZ is carried out as a first step, and LSZ and SLSZ are estimated next as same as the previous model. The proposed model by using GPS buoy was applied for a tsunami scenario in the Nankai Trough. As a result </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AGUFMNH22A..06C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AGUFMNH22A..06C">Determination of Tsunami Warning Criteria for Current Velocity</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Chen, R.; Wang, D. 2015-12-01 Present Tsunami warning issuance largely depends on an event's predicted wave height and inundation depth. Specifically, a warning is issued if the on-shore wave height is greater than 1m. This project examines whether any consideration should be given to current velocity. We apply the idea of force balance to determine theoretical minimum velocity thresholds for injuring people and damaging properties as a function of wave height. Results show that even at a water depth of less than 1m, a current velocity of 2 m/s is enough to pose a threat to humans and cause potential damage to cars and houses. Next, we employ a 1-dimensional shallow water model to simulate Tsunamis with various amplitudes and an assumed wavelength of 250km. This allows for the profiling of current velocity and wave height behavior as the Tsunamis reach shore. We compare this data against our theoretical thresholds to see if any real world scenarios would be dangerous to people and properties. We conclude that for such Tsunamis, the present warning criteria are effective at protecting people against larger events with amplitude greater than ~0.3m. However, for events with amplitude less than ~0.2m, it is possible to have waves less than 1m with current velocity high enough to endanger humans. Thus, the inclusion of current velocity data would help the present Tsunami warning criteria become more robust and efficient, especially for smaller Tsunami events. </li> <li> <a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70000187','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70000187">Coarse-clast ridge complexes of the Caribbean: A preliminary basis for distinguishing tsunami and storm-wave origins</a> <a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a> Morton, R.A.; Richmond, B.M.; Jaffe, B.E.; Gelfenbaum, G. 2008-01-01 Coastal gravel-ridge complexes deposited on islands in the Caribbean Sea are recorders of past extreme-wave events that could be associated with either tsunamis or hurricanes. The ridge complexes of Bonaire, Jamaica, Puerto Rico (Isla de Mona), and Guadeloupe consist of polymodal clasts ranging in size from sand to coarse boulders that are derived from the adjacent coral reefs or subjacent rock platforms. Ridge-complex morphologies and crest elevations are largely controlled by availability of sediments, clast sizes, and heights of wave runup. The ridge complexes are internally organized, display textural sorting and a broad range of ages including historical events. Some display seaward-dipping beds and ridge-and-swale topography, and some terminate in fans or steep avalanche slopes. Together, the morphologic, sedimentologic, lithostratigraphic, and chronostratigraphic evidence indicates that shore-parallet ridge complexes composed of gravel and sand that are tens of meters wide and several meters thick are primarily storm-constructed features that have accumulated for a few centuries or millennia as a result of multiple high-frequency intense-wave events. They are not entirely the result of one or a few tsunamis as recently reported. Tsunami deposition may account for some of the lateral ridge-complex accretion or boulder fields and isolated blocks that are associated with the ridge complexes. Copyright ?? 2008, SEPM (Society for Sedimentary Geology). </li> <li> <a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19840024048','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19840024048">Time dependent wave envelope finite difference analysis of sound propagation</a> <a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a> Baumeister, K. J. 1984-01-01 A transient finite difference wave envelope formulation is presented for sound propagation, without steady flow. Before the finite difference equations are formulated, the governing wave equation is first transformed to a form whose solution tends not to oscillate along the propagation direction. This transformation reduces the required number of grid points by an order of magnitude. Physically, the transformed pressure represents the amplitude of the conventional sound wave. The derivation for the wave envelope transient wave equation and appropriate boundary conditions are presented as well as the difference equations and stability requirements. To illustrate the method, example solutions are presented for sound propagation in a straight hard wall duct and in a two dimensional straight soft wall duct. The numerical results are in good agreement with exact analytical results. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AGUFM.S21A4406A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AGUFM.S21A4406A">Optimization of the Number and Location of Tsunami Stations in a Tsunami Warning System</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> An, C.; Liu, P. L. F.; Pritchard, M. E. 2014-12-01 Optimizing the number and location of tsunami stations in designing a tsunami warning system is an important and practical problem. It is always desirable to maximize the capability of the data obtained from the stations for constraining the earthquake source parameters, and to minimize the number of stations at the same time. During the 2011 Tohoku tsunami event, 28 coastal gauges and DART buoys in the near-field recorded tsunami waves, providing an opportunity for assessing the effectiveness of those stations in identifying the earthquake source parameters. Assuming a single-plane fault geometry, inversions of tsunami data from combinations of various number (1~28) of stations and locations are conducted and evaluated their effectiveness according to the residues of the inverse method. Results show that the optimized locations of stations depend on the number of stations used. If the stations are optimally located, 2~4 stations are sufficient to constrain the source parameters. Regarding the optimized location, stations must be uniformly spread in all directions, which is not surprising. It is also found that stations within the source region generally give worse constraint of earthquake source than stations farther from source, which is due to the exaggeration of model error in matching large amplitude waves at near-source stations. Quantitative discussions on these findings will be given in the presentation. Applying similar analysis to the Manila Trench based on artificial scenarios of earthquakes and tsunamis, the optimal location of tsunami stations are obtained, which provides guidance of deploying a tsunami warning system in this region. </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li class="active">17</li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> </div> <div id="page_18" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li class="active">18</li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="341"> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFMNH12A..05A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFMNH12A..05A">High-Resolution Observations of a Meteo-Tsunami</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Assink, J. D.; Evers, L. G.; Smink, M.; Apituley, A. 2017-12-01 In the early morning of 29 May 2017, unusually large waves of over 2 m height hit the west coast of the Netherlands, leading to some property damage. The waves were due to a meteo-tsunami, which is a tsunami of meteorological origin, unlike seismogenic tsunamis. This particular event was caused by a rapidly moving cold front which featured a sharp squall line that moved towards the coast. Associated was a large perturbation in air pressure of 5 hPa which, along with Proudman resonance effects and the upsloping seabottom lead to the tidal surge. While the meteorological conditions leading up to such an event are relatively common, the more extreme events appear to happen under specific conditions only. As a result of the meteo-tsunami, gravity waves were observed all over the Netherlands with a variety of meteorlogical instruments, including weather radar, ceilometers and a network of microbarometers that are typically used for the detection of infrasound. In this presentation, these high-resolution observations of gravity waves are compared with mesoscale weather models. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017PApGe.174.3003G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017PApGe.174.3003G">Tsunami Detection by High Frequency Radar Beyond the Continental Shelf: II. Extension of Time Correlation Algorithm and Validation on Realistic Case Studies</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Grilli, Stéphan T.; Guérin, Charles-Antoine; Shelby, Michael; Grilli, Annette R.; Moran, Patrick; Grosdidier, Samuel; Insua, Tania L. 2017-08-01 In past work, tsunami detection algorithms (TDAs) have been proposed, and successfully applied to offline tsunami detection, based on analyzing tsunami currents inverted from high-frequency (HF) radar Doppler spectra. With this method, however, the detection of small and short-lived tsunami currents in the most distant radar ranges is challenging due to conflicting requirements on the Doppler spectra integration time and resolution. To circumvent this issue, in Part I of this work, we proposed an alternative TDA, referred to as time correlation (TC) TDA, that does not require inverting currents, but instead detects changes in patterns of correlations of radar signal time series measured in pairs of cells located along the main directions of tsunami propagation (predicted by geometric optics theory); such correlations can be maximized when one signal is time-shifted by the pre-computed long wave propagation time. We initially validated the TC-TDA based on numerical simulations of idealized tsunamis in a simplified geometry. Here, we further develop, extend, and apply the TC algorithm to more realistic tsunami case studies. These are performed in the area West of Vancouver Island, BC, where Ocean Networks Canada recently deployed a HF radar (in Tofino, BC), to detect tsunamis from far- and near-field sources, up to a 110 km range. Two case studies are considered, both simulated using long wave models (1) a far-field seismic, and (2) a near-field landslide, tsunami. Pending the availability of radar data, a radar signal simulator is parameterized for the Tofino HF radar characteristics, in particular its signal-to-noise ratio with range, and combined with the simulated tsunami currents to produce realistic time series of backscattered radar signal from a dense grid of cells. Numerical experiments show that the arrival of a tsunami causes a clear change in radar signal correlation patterns, even at the most distant ranges beyond the continental shelf, thus making an </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018JGRB..123.1711T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018JGRB..123.1711T">Sensitivities of Near-field Tsunami Forecasts to Megathrust Deformation Predictions</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Tung, S.; Masterlark, T. 2018-02-01 This study reveals how modeling configurations of forward and inverse analyses of coseismic deformation data influence the estimations of seismic and tsunami sources. We illuminate how the predictions of near-field tsunami change when (1) a heterogeneous (HET) distribution of crustal material is introduced to the elastic dislocation model, and (2) the near-trench rupture is either encouraged or suppressed to invert spontaneous coseismic displacements. Hypothetical scenarios of megathrust earthquakes are studied with synthetic Global Positioning System displacements in Cascadia. Finite-element models are designed to mimic the subsurface heterogeneity across the curved subduction margin. The HET lithospheric domain modifies the seafloor displacement field and alters tsunami predictions from those of a homogeneous (HOM) crust. Uncertainties persist as the inverse analyses of geodetic data produce nonrealistic slip artifacts over the HOM domain, which propagates into the prediction errors of subsequent tsunami arrival and amplitudes. A stochastic analysis further shows that the uncertainties of seismic tomography models do not degrade the solution accuracy of HET over HOM. Whether the source ruptures near the trench also controls the details of the seafloor disturbance. Deeper subsurface slips induce more seafloor uplift near the coast and cause an earlier arrival of tsunami waves than surface-slipping events. We suggest using the solutions of zero-updip-slip and zero-updip-slip-gradient rupture boundary conditions as end-members to constrain the tsunami behavior for forecasting purposes. The findings are important for the near-field tsunami warning that primarily relies on the near-real-time geodetic or seismic data for source calibration before megawaves hit the nearest shore upon tsunamigenic events. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018GeoJI.tmp..184C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018GeoJI.tmp..184C">Influence of off-great-circle propagation of Rayleigh waves on event-based surface wave tomography in Northeast China</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Chen, Haopeng; Ni, Sidao; Chu, Risheng; Chong, Jiajun; Liu, Zhikun; Zhu, Liangbao 2018-05-01 Surface waves are generally assumed to propagate along great-circle paths in most surface-wave tomography. However, when lateral heterogeneity is strong, off-great-circle propagation may occur and deteriorate surface wave tomography results based on the great-circle assumption. In this study, we used teleseismic waveforms recorded by the NECESSArray in Northeast China to study off-great-circle propagation of Rayleigh waves using the beamforming method and evaluated the influence of off-great-circle propagation on event-based surface wave tomography. The results show that arrival angle anomalies generally increase with decreasing period. The arrival angle anomalies at 60 and 50 s periods are smaller than that at 40 and 30 s periods, which indicates that the off-great-circle propagation is relatively weak for longer periods. At 30 s period, the arrival angle anomalies are relatively larger and some of the measurements can exceed 20°, which represents a strong off-great-circle propagation effect. In some areas, the arrival angle anomalies of adjacent events differ significantly, which may be attributed to multipathing propagation of surface waves. To evaluate the influence of off-great-circle propagation on event-based surface wave tomography, we used measured arrival angle anomalies to correct two-station phase velocity measurements, and performed azimuthal anisotropy tomography using dispersion datasets with and without the arrival angle correction. At longer periods, such as 60 s, the influence of off-great-circle propagation on surface wave tomography is weak even though the corrected model has better data fit than the uncorrected model. However, the influence of off-great-circle propagation is non-negligible at short periods. The tomography results at 30 s period show that the differences in phase velocity, the strength of anisotropy and the fast direction can be as large as 1.5 per cent, 1.0 per cent and 30°, respectively. Furthermore, the corrected phase </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014RMRE...47..561M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014RMRE...47..561M">Long-Wavelength Elastic Wave Propagation Across Naturally Fractured Rock Masses</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Mohd-Nordin, Mohd Mustaqim; Song, Ki-Il; Cho, Gye-Chun; Mohamed, Zainab 2014-03-01 Geophysical site investigation techniques based on elastic waves have been widely used to characterize rock masses. However, characterizing jointed rock masses by using such techniques remains challenging because of a lack of knowledge about elastic wave propagation in multi-jointed rock masses. In this paper, the roughness of naturally fractured rock joint surfaces is estimated by using a three-dimensional (3D) image-processing technique. The classification of the joint roughness coefficient (JRC) is enhanced by introducing the scan line technique. The peak-to-valley height is selected as a key indicator for JRC classification. Long-wavelength P-wave and torsional S-wave propagation across rock masses containing naturally fractured joints are simulated through the quasi-static resonant column (QSRC) test. In general, as the JRC increases, the S-wave velocity increases within the range of stress levels considered in this paper, whereas the P-wave velocity and the damping ratio of the shear wave decrease. In particular, the two-dimensional joint specimen underestimates the S-wave velocity while overestimating the P-wave velocity. This suggests that 3D joint surfaces should be implicated to obtain the reliable elastic wave velocity in jointed rock masses. The contact characteristic and degree of roughness and waviness of the joint surface are identified as a factor influencing P-wave and S-wave propagation in multi-jointed rock masses. The results indicate a need for a better understanding of the sensitivity of contact area alterations to the elastic wave velocity induced by changes in normal stress. This paper's framework can be a reference for future research on elastic wave propagation in naturally multi-jointed rock masses. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2003AGUFMOS22B1154W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2003AGUFMOS22B1154W">Volcanic Tsunami Generation in the Aleutian Arc of Alaska</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Waythomas, C. F.; Watts, P. 2003-12-01 , geological evidence of tsunamis, such as tsunami deposits on land, should be found in the area around Augustine Island. Paradoxically, unequivocal evidence for tsunami inundation has been found. Augustine Volcano is the most historically active volcano in the Cook Inlet region and a future tsunami from the volcano would have devastating consequences to villages, towns, oil-production facilities, and the fishing industry, especially if it occurred at high tide (the tidal range in this area is about 5 m). Numerical simulation experiments of tsunami generation, propagation and inundation using a subaerial debris avalanche source at Augustine volcano indicate only modest wave generation because of the shallow water surrounding the volcano (maximum water depth about 25 m). Lahar flows produced during eruptions at snow and ice clad volcanoes in the Aleutian arc also deliver copious amounts of sediment to the sea. These flows only rarely transform to subaqueous debris flows that may become tsunamigenic. However, the accumulation of loose, unconsolidated sediment on the continental shelf may lead to subaqueous debris flows and landslides if these deposits become mobilized by large earthquakes. Tsunamis produced by this mechanism could potentially reach coastlines all along the Pacific Rim. Finally, recent work in the western Aleutian Islands indicates that many of the island volcanoes in this area have experienced large-scale flank collapse. Because these volcanoes are surrounded by deep water, the tsunami hazard associated with a future sector collapse could be significant. </li> <li> <a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/22518783-apparent-cross-field-superslow-propagation-magnetohydrodynamic-waves-solar-plasmas','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/22518783-apparent-cross-field-superslow-propagation-magnetohydrodynamic-waves-solar-plasmas">APPARENT CROSS-FIELD SUPERSLOW PROPAGATION OF MAGNETOHYDRODYNAMIC WAVES IN SOLAR PLASMAS</a> <a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a> Kaneko, T.; Yokoyama, T.; Goossens, M. 2015-10-20 In this paper we show that the phase-mixing of continuum Alfvén waves and/or continuum slow waves in the magnetic structures of the solar atmosphere as, e.g., coronal arcades, can create the illusion of wave propagation across the magnetic field. This phenomenon could be erroneously interpreted as fast magnetosonic waves. The cross-field propagation due to the phase-mixing of continuum waves is apparent because there is no real propagation of energy across the magnetic surfaces. We investigate the continuous Alfvén and slow spectra in two-dimensional (2D) Cartesian equilibrium models with a purely poloidal magnetic field. We show that apparent superslow propagation acrossmore » the magnetic surfaces in solar coronal structures is a consequence of the existence of continuum Alfvén waves and continuum slow waves that naturally live on those structures and phase-mix as time evolves. The apparent cross-field phase velocity is related to the spatial variation of the local Alfvén/slow frequency across the magnetic surfaces and is slower than the Alfvén/sound velocities for typical coronal conditions. Understanding the nature of the apparent cross-field propagation is important for the correct analysis of numerical simulations and the correct interpretation of observations.« less </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012JOC....33...57J','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012JOC....33...57J">Re-evaluation of ``;The Propagation of Radiation in the Spherical Wave Form''</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Joshi, Narahari V. 2012-03-01 It is well accepted that radiation propagates in the free space (without obstacles) in a spherical wave form as well as in a plane wave form. Almost all observed phenomena such as interference, diffraction etc are explained satisfactorily on the basis of spherical wave propagation with a slight alteration in the mathematical treatment. However, one of the fundamental aspects, namely the intensity of the radiation as a function of the distance still remains an unsolved problem as the intensity varies with <italic>1/</italic>(distance)<italic>2</italic> when one represents the propagation in terms of spherical waves while it is independent of the distance if it is considered as a plane wave. In order to understand this puzzle, the propagation by a spherical wave form is reexamined. It is found that conversion of fields into particle (vice versa), via the field quantization process, explains several dilemma related with the radiation propagation. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19730019124','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19730019124">ATS-5 millimeter wave propagation measurements</a> <a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a> Ippolito, L. J. 1973-01-01 Long term experimental measurements to determine the propagation characteristics of 15 and 32 GHz earth-space links and to evaluate performance characteristics of operational millimeter wave systems are reported. The ATS 5 millimeter wave experimental link experienced attenuation and fading characteristics as a function of rainfall rate and other meteorological parameters. A method of site selection for the lowest attenuation rainfall rate improved reception tremendously. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010EGUGA..12.2588G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010EGUGA..12.2588G">Modelling of Charles Darwin's tsunami reports</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Galiev, Shamil 2010-05-01 Darwin landed at Valdivia and Concepcion, Chile, just before, during, and after a great 1835 earthquake. He described his impressions and results of the earthquake-induced natural catastrophe in The Voyage of the Beagle. His description of the tsunami could easily be read as a report from Indonesia or Sri Lanka, after the catastrophic tsunami of 26 December 2004. In particular, Darwin emphasised the dependence of earthquake-induced waves on a form of the coast and the coastal depth: ‘… Talcuhano and Callao are situated at the head of great shoaling bays, and they have always suffered from this phenomenon; whereas, the town of Valparaiso, which is seated close on the border of a profound ocean... has never been overwhelmed by one of these terrific deluges…' . He reports also, that ‘… the whole body of the sea retires from the coast, and then returns in great waves of overwhelming force ...' (we cite the Darwin's sentences following researchspace. auckland. ac. nz/handle/2292/4474). The coastal evolution of a tsunami was analytically studied in many publications (see, for example, Synolakis, C.E., Bernard, E.N., 2006. Philos. Trans. R. Soc., Ser. A, 364, 2231-2265; Tinti, S., Tonini, R. 205. J.Fluid Mech., 535, 11-21). However, the Darwin's reports and the influence of the coastal depth on the formation and the evolution of the steep front and the profile of tsunami did not practically discuss. Recently, a mathematical theory of these phenomena was presented in researchspace. auckland. ac. nz/handle/2292/4474. The theory describes the waves which are excited due to nonlinear effects within a shallow coastal zone. The tsunami elevation is described by two components: . Here is the linear (prime) component. It describes the wave coming from the deep ocean. is the nonlinear component. This component may become very important near the coastal line. After that the theory of the shallow waves is used. This theory yields the linear equation for and the weakly </li> <li> <a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20130011523','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20130011523">On the Propagation and Interaction of Spherical Blast Waves</a> <a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a> Kandula, Max; Freeman, Robert 2007-01-01 The characteristics and the scaling laws of isolated spherical blast waves have been briefly reviewed. Both self-similar solutions and numerical solutions of isolated blast waves are discussed. Blast profiles in the near-field (strong shock region) and the far-field (weak shock region) are examined. Particular attention is directed at the blast overpressure and shock propagating speed. Consideration is also given to the interaction of spherical blast waves. Test data for the propagation and interaction of spherical blast waves emanating from explosives placed in the vicinity of a solid propellant stack are presented. These data are discussed with regard to the scaling laws concerning the decay of blast overpressure. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFMNH23A0234M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFMNH23A0234M">Assessing Potential Tsunami Sources for Extreme Wave Deposits on Southwest Isla de Mona, Puerto Rico, Using Numerical Simulations and Hydrodynamic Boulder Transport Equations</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Matos-Llavona, P. I.; Lopez, A. M.; Jaffe, B. E.; Richmond, B. M. 2017-12-01 Extreme waves on coastlines pose a threat to human life, habitats, and critical coastal infrastructure. Geological evidence of extreme waves can provide valuable information on the magnitude, frequency, wave characteristics and source of past events, thus improving coastal hazard assessment. Reef-rock boulders, as much as 5m in diameter, are found up to 500 m inland on the southwestern coast of Isla de Mona, Puerto Rico. These boulders were emplaced 4000 years ago based on age dates from encrusting corals (Taggart et al., 1993). This study aims to identify an event capable of forming these deposits. For this, a numerical model of the 1918 Mona Passage tsunami was constructed using the New Evolution of Ocean Wave (NEOWAVE) model with three nested grids of 3, 1 and 1/3 arc-second resolution, respectively. A second simulation of a submarine landslide (1km3 volume) located 300m from the southwestern Mona shoreline was run using 3D Tsunami Solution Using Navier-Stokes Algorithm with Multiple Interfaces (TSUNAMI3D). The resulting inundation and wave heights at the shoreline are compared to minimum wave heights required to initiate transport (sub-aerial and submerged) of measured boulders and idealized cubic boulders with varying volumes. The 1918 Mona Passage tsunami simulation shows no significant inundation on the SSW Mona coast and a maximum wave height of 1.3m, which is below the minimum wave height required to initiate transport of a 1m diameter boulder. This result suggests that a tsunami like the one generated in 1918 is not capable of transporting even the smaller boulders. However, the submarine landslide generated extensive inundation on the SW coast with maximum wave height of 10m at the shoreline, 20m run-up, and 900m inundation distance. This is greater than the minimum wave height needed to initiate transport in both submerged and subaerial pre-transport settings; therefore, a submarine landslide with characteristics of the modeled landslide can form the </li> <li> <a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/22308064-post-fukushima-tsunami-simulations-malaysian-coasts','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/22308064-post-fukushima-tsunami-simulations-malaysian-coasts">Post Fukushima tsunami simulations for Malaysian coasts</a> <a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a> Koh, Hock Lye, E-mail: kohhl@ucsiuniversity.edu.my; Teh, Su Yean, E-mail: syteh@usm.my; Abas, Mohd Rosaidi Che The recent recurrences of mega tsunamis in the Asian region have rekindled concern regarding potential tsunamis that could inflict severe damage to affected coastal facilities and communities. The 11 March 2011 Fukushima tsunami that crippled nuclear power plants in Northern Japan has further raised the level of caution. The recent discovery of petroleum reserves in the coastal water surrounding Malaysia further ignites the concern regarding tsunami hazards to petroleum facilities located along affected coasts. Working in a group, federal government agencies seek to understand the dynamics of tsunami and their impacts under the coordination of the Malaysian National Centre formore » Tsunami Research, Malaysian Meteorological Department. Knowledge regarding the generation, propagation and runup of tsunami would provide the scientific basis to address safety issues. An in-house tsunami simulation models known as TUNA has been developed by the authors to assess tsunami hazards along affected beaches so that mitigation measures could be put in place. Capacity building on tsunami simulation plays a critical role in the development of tsunami resilience. This paper aims to first provide a simple introduction to tsunami simulation towards the achievement of tsunami simulation capacity building. The paper will also present several scenarios of tsunami dangers along affected Malaysia coastal regions via TUNA simulations to highlight tsunami threats. The choice of tsunami generation parameters reflects the concern following the Fukushima tsunami.« less </li> <li> <a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70055623','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70055623">Simulated tsunami inundation for a range of Cascadia megathrust earthquake scenarios at Bandon, Oregon, USA</a> <a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a> Witter, Robert C.; Zhang, Yinglong J.; Wang, Kelin; Priest, George R.; Goldfinger, Chris; Stimely, Laura; English, John T.; Ferro, Paul A. 2013-01-01 Characterizations of tsunami hazards along the Cascadia subduction zone hinge on uncertainties in megathrust rupture models used for simulating tsunami inundation. To explore these uncertainties, we constructed 15 megathrust earthquake scenarios using rupture models that supply the initial conditions for tsunami simulations at Bandon, Oregon. Tsunami inundation varies with the amount and distribution of fault slip assigned to rupture models, including models where slip is partitioned to a splay fault in the accretionary wedge and models that vary the updip limit of slip on a buried fault. Constraints on fault slip come from onshore and offshore paleoseismological evidence. We rank each rupture model using a logic tree that evaluates a model’s consistency with geological and geophysical data. The scenarios provide inputs to a hydrodynamic model, SELFE, used to simulate tsunami generation, propagation, and inundation on unstructured grids with <5–15 m resolution in coastal areas. Tsunami simulations delineate the likelihood that Cascadia tsunamis will exceed mapped inundation lines. Maximum wave elevations at the shoreline varied from ∼4 m to 25 m for earthquakes with 9–44 m slip and Mw 8.7–9.2. Simulated tsunami inundation agrees with sparse deposits left by the A.D. 1700 and older tsunamis. Tsunami simulations for large (22–30 m slip) and medium (14–19 m slip) splay fault scenarios encompass 80%–95% of all inundation scenarios and provide reasonable guidelines for land-use planning and coastal development. The maximum tsunami inundation simulated for the greatest splay fault scenario (36–44 m slip) can help to guide development of local tsunami evacuation zones. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFM.S11B0574F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFM.S11B0574F">Multiple geophysical observations indicate possible splay fault activation during the 2006 Java Tsunami earthquake</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Fan, W.; Bassett, D.; Denolle, M.; Shearer, P. M.; Ji, C.; Jiang, J. 2017-12-01 The 2006 Mw 7.8 Java earthquake was a tsunami earthquake, exhibiting frequency-dependent seismic radiation along strike. High-frequency global back-projection results suggest two distinct rupture stages. The first stage lasted 65 s with a rupture speed of 1.2 km/s, while the second stage lasted from 65 to 150 s with a rupture speed of 2.7 km/s. In addition, P-wave high-frequency radiated energy and fall-off rates indicate a rupture transition at 60 s. High-frequency radiators resolved with back-projection during the second stage spatially correlate with splay fault traces mapped from residual free-air gravity anomalies. These splay faults also collocate with a major tsunami source associated with the earthquake inferred from tsunami first-crest back-propagation simulation. These correlations suggest that the splay faults may have been reactivated during the Java earthquake, as has been proposed for other tsunamigenic earthquakes, such as the 1944 Mw 8.1 Tonankai earthquake in the Nankai Trough. </li> <li> <a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70030665','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70030665">Probabilistic analysis of tsunami hazards</a> <a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a> Geist, E.L.; Parsons, T. 2006-01-01 Determining the likelihood of a disaster is a key component of any comprehensive hazard assessment. This is particularly true for tsunamis, even though most tsunami hazard assessments have in the past relied on scenario or deterministic type models. We discuss probabilistic tsunami hazard analysis (PTHA) from the standpoint of integrating computational methods with empirical analysis of past tsunami runup. PTHA is derived from probabilistic seismic hazard analysis (PSHA), with the main difference being that PTHA must account for far-field sources. The computational methods rely on numerical tsunami propagation models rather than empirical attenuation relationships as in PSHA in determining ground motions. Because a number of source parameters affect local tsunami runup height, PTHA can become complex and computationally intensive. Empirical analysis can function in one of two ways, depending on the length and completeness of the tsunami catalog. For site-specific studies where there is sufficient tsunami runup data available, hazard curves can primarily be derived from empirical analysis, with computational methods used to highlight deficiencies in the tsunami catalog. For region-wide analyses and sites where there are little to no tsunami data, a computationally based method such as Monte Carlo simulation is the primary method to establish tsunami hazards. Two case studies that describe how computational and empirical methods can be integrated are presented for Acapulco, Mexico (site-specific) and the U.S. Pacific Northwest coastline (region-wide analysis). </li> <li> <a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/24650976','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/24650976">Source and listener directivity for interactive wave-based sound propagation.</a> <a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a> Mehra, Ravish; Antani, Lakulish; Kim, Sujeong; Manocha, Dinesh 2014-04-01 We present an approach to model dynamic, data-driven source and listener directivity for interactive wave-based sound propagation in virtual environments and computer games. Our directional source representation is expressed as a linear combination of elementary spherical harmonic (SH) sources. In the preprocessing stage, we precompute and encode the propagated sound fields due to each SH source. At runtime, we perform the SH decomposition of the varying source directivity interactively and compute the total sound field at the listener position as a weighted sum of precomputed SH sound fields. We propose a novel plane-wave decomposition approach based on higher-order derivatives of the sound field that enables dynamic HRTF-based listener directivity at runtime. We provide a generic framework to incorporate our source and listener directivity in any offline or online frequency-domain wave-based sound propagation algorithm. We have integrated our sound propagation system in Valve's Source game engine and use it to demonstrate realistic acoustic effects such as sound amplification, diffraction low-passing, scattering, localization, externalization, and spatial sound, generated by wave-based propagation of directional sources and listener in complex scenarios. We also present results from our preliminary user study. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://www.agu.org/pubs/crossref/2011/2010GL046498.shtml','USGSPUBS'); return false;" href="http://www.agu.org/pubs/crossref/2011/2010GL046498.shtml">The 25 October 2010 Mentawai tsunami earthquake, from real-time discriminants, finite-fault rupture, and tsunami excitation</a> <a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a> Newman, Andrew V.; Hayes, Gavin P.; Wei, Yong; Convers, Jaime 2011-01-01 The moment magnitude 7.8 earthquake that struck offshore the Mentawai islands in western Indonesia on 25 October 2010 created a locally large tsunami that caused more than 400 human causalities. We identify this earthquake as a rare slow-source tsunami earthquake based on: 1) disproportionately large tsunami waves; 2) excessive rupture duration near 125 s; 3) predominantly shallow, near-trench slip determined through finite-fault modeling; and 4) deficiencies in energy-to-moment and energy-to-duration-cubed ratios, the latter in near-real time. We detail the real-time solutions that identified the slow-nature of this event, and evaluate how regional reductions in crustal rigidity along the shallow trench as determined by reduced rupture velocity contributed to increased slip, causing the 5–9 m local tsunami runup and observed transoceanic wave heights observed 1600 km to the southeast. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015IzAOP..51..557B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015IzAOP..51..557B">Propagation of inertial-gravity waves on an island shelf</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Bondur, V. G.; Sabinin, K. D.; Grebenyuk, Yu. V. 2015-09-01 The propagation of inertial-gravity waves (IGV) at the boundary of the Pacific shelf near the island of Oahu (Hawaii), whose generation was studied in the first part of this work [1], is analyzed. It is shown that a significant role there is played by the plane oblique waves; whose characteristics were identified by the method of estimating 3D wave parameters for the cases when the measurements are available only for two verticals. It is established that along with the descending propagation of energy that is typical of IGVs, wave packets ascend from the bottom to the upper layers, which is caused by the emission of waves from intense jets of discharged waters flowing out of a diffusor located at the bottom. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2005EL.....72..341G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2005EL.....72..341G">Generic short-time propagation of sharp-boundaries wave packets</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Granot, E.; Marchewka, A. 2005-11-01 A general solution to the "shutter" problem is presented. The propagation of an arbitrary initially bounded wave function is investigated, and the general solution for any such function is formulated. It is shown that the exact solution can be written as an expression that depends only on the values of the function (and its derivatives) at the boundaries. In particular, it is shown that at short times (t << 2mx2/hbar, where x is the distance to the boundaries) the wave function propagation depends only on the wave function's values (or its derivatives) at the boundaries of the region. Finally, we generalize these findings to a non-singular wave function (i.e., for wave packets with finite-width boundaries) and suggest an experimental verification. </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li class="active">18</li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> </div> <div id="page_19" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li class="active">19</li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="361"> <li> <a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/pages/biblio/1369205-simulations-seismic-wave-propagation-mars','SCIGOV-DOEP'); return false;" href="https://www.osti.gov/pages/biblio/1369205-simulations-seismic-wave-propagation-mars">Simulations of Seismic Wave Propagation on Mars</a> <a target="_blank" href="http://www.osti.gov/pages">DOE PAGES</a> Bozdağ, Ebru; Ruan, Youyi; Metthez, Nathan; ... 2017-03-23 In this paper, we present global and regional synthetic seismograms computed for 1D and 3D Mars models based on the spectral-element method. For global simulations, we implemented a radially-symmetric Mars model with a 110 km thick crust. For this 1D model, we successfully benchmarked the 3D seismic wave propagation solver SPECFEM3D_GLOBE against the 2D axisymmetric wave propagation solver AxiSEM at periods down to 10 s. We also present higher-resolution body-wave simulations with AxiSEM down to 1 s in a model with a more complex 1D crust, revealing wave propagation effects that would have been difficult to interpret based on raymore » theory. For 3D global simulations based on SPECFEM3D_GLOBE, we superimposed 3D crustal thickness variations capturing the distinct crustal dichotomy between Mars’ northern and southern hemispheres, as well as topography, ellipticity, gravity, and rotation. The global simulations clearly indicate that the 3D crust speeds up body waves compared to the reference 1D model, whereas it significantly changes surface waveforms and their dispersive character depending on its thickness. We also perform regional simulations with the solver SES3D based on 3D crustal models derived from surface composition, thereby addressing the effects of various distinct crustal features down to 2 s. The regional simulations confirm the strong effects of crustal variations on waveforms. Finally, we conclude that the numerical tools are ready for examining more scenarios, including various other seismic models and sources.« less </li> <li> <a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/1369205','SCIGOV-STC'); return false;" href="https://www.osti.gov/servlets/purl/1369205">Simulations of Seismic Wave Propagation on Mars</a> <a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a> Bozdağ, Ebru; Ruan, Youyi; Metthez, Nathan In this paper, we present global and regional synthetic seismograms computed for 1D and 3D Mars models based on the spectral-element method. For global simulations, we implemented a radially-symmetric Mars model with a 110 km thick crust. For this 1D model, we successfully benchmarked the 3D seismic wave propagation solver SPECFEM3D_GLOBE against the 2D axisymmetric wave propagation solver AxiSEM at periods down to 10 s. We also present higher-resolution body-wave simulations with AxiSEM down to 1 s in a model with a more complex 1D crust, revealing wave propagation effects that would have been difficult to interpret based on raymore » theory. For 3D global simulations based on SPECFEM3D_GLOBE, we superimposed 3D crustal thickness variations capturing the distinct crustal dichotomy between Mars’ northern and southern hemispheres, as well as topography, ellipticity, gravity, and rotation. The global simulations clearly indicate that the 3D crust speeds up body waves compared to the reference 1D model, whereas it significantly changes surface waveforms and their dispersive character depending on its thickness. We also perform regional simulations with the solver SES3D based on 3D crustal models derived from surface composition, thereby addressing the effects of various distinct crustal features down to 2 s. The regional simulations confirm the strong effects of crustal variations on waveforms. Finally, we conclude that the numerical tools are ready for examining more scenarios, including various other seismic models and sources.« less </li> <li> <a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/1050486','SCIGOV-STC'); return false;" href="https://www.osti.gov/servlets/purl/1050486">Tsunamis warning from space :Ionosphere seismology</a> <a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a> Larmat, Carene 2012-09-04 Ionosphere is the layer of the atmosphere from about 85 to 600km containing electrons and electrically charged atoms that are produced by solar radiation. Perturbations - layering affected by day and night, X-rays and high-energy protons from the solar flares, geomagnetic storms, lightning, drivers-from-below. Strategic for radio-wave transmission. This project discusses the inversion of ionosphere signals, tsunami wave amplitude and coupling parameters, which improves tsunami warning systems. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016EGUGA..1817332C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016EGUGA..1817332C">Coupled Eulerian-Lagrangian transport of large debris by tsunamis</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Conde, Daniel A. S.; Ferreira, Rui M. L.; Sousa Oliveira, Carlos 2016-04-01 Tsunamis are notorious for the large disruption they can cause on coastal environments, not only due to the imparted momentum of the incoming wave but also due to its capacity to transport large quantities of solid debris, either from natural or human-made sources, over great distances. A 2DH numerical model under development at CERIS-IST (Ferreira et al., 2009; Conde, 2013) - STAV2D - capable of simulating solid transport in both Eulerian and Lagrangian paradigms will be used to assess the relevance of Lagrangian-Eulerian coupling when modelling the transport of solid debris by tsunamis. The model has been previously validated and applied to tsunami scenarios (Conde, 2013), being well-suited for overland tsunami propagation and capable of handling morphodynamic changes in estuaries and seashores. The discretization scheme is an explicit Finite Volume technique employing flux-vector splitting and a reviewed Roe-Riemann solver. Source term formulations are employed in a semi-implicit way, including the two-way coupling of the Lagrangian and Eulerian solvers by means of conservative mass and momentum transfers between fluid and solid phases. The model was applied to Sines Port, a major commercial port in Portugal, where two tsunamigenic scenarios are considered: an 8.5 Mw scenario, consistent with the Great Lisbon Earthquake and Tsunami of the 1st November 1755 (Baptista, 2009), and an hypothetical 9.5 Mw worst-case scenario based on the same historical event. Open-ocean propagation of these scenarios were simulated with GeoClaw model from ClawPack (Leveque, 2011). Following previous efforts on the modelling of debris transport by tsunamis in seaports (Conde, 2015), this work discusses the sensitivity of the obtained results with respect to the phenomenological detail of the employed Eulerian-Lagrangian formulation and the resolution of the mesh used in the Eulerian solver. The results have shown that the fluid to debris mass ratio is the key parameter regarding the </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFMSH33B2783T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFMSH33B2783T">Wave Propagation Around Coronal Structures: Stratification, Buoyancy, Small Scale Formation</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Tomlinson, S. M.; Rappazzo, F.; Velli, M. 2017-12-01 We study the propagation of waves in a coronal medium characterized by stratification and structure in density. temperature and magnetic field. It is well known that average gradients affect the propagation of Alfvén and other MHD waves via reflection, phase mixing, resonant absorption and other coupling phenomena. Here we discuss how the interplay of propagation on inhomogeneous, stratified structures with nonlinear interactions may lead to interesting effects including preferential heating, buoyancy, and plasma acceleration. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012PMB....57L...9R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012PMB....57L...9R">Counter-propagating wave interaction for contrast-enhanced ultrasound imaging</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Renaud, G.; Bosch, J. G.; ten Kate, G. L.; Shamdasani, V.; Entrekin, R.; de Jong, N.; van der Steen, A. F. W. 2012-11-01 Most techniques for contrast-enhanced ultrasound imaging require linear propagation to detect nonlinear scattering of contrast agent microbubbles. Waveform distortion due to nonlinear propagation impairs their ability to distinguish microbubbles from tissue. As a result, tissue can be misclassified as microbubbles, and contrast agent concentration can be overestimated; therefore, these artifacts can significantly impair the quality of medical diagnoses. Contrary to biological tissue, lipid-coated gas microbubbles used as a contrast agent allow the interaction of two acoustic waves propagating in opposite directions (counter-propagation). Based on that principle, we describe a strategy to detect microbubbles that is free from nonlinear propagation artifacts. In vitro images were acquired with an ultrasound scanner in a phantom of tissue-mimicking material with a cavity containing a contrast agent. Unlike the default mode of the scanner using amplitude modulation to detect microbubbles, the pulse sequence exploiting counter-propagating wave interaction creates no pseudoenhancement behind the cavity in the contrast image. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AGUFM.S14A..03G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AGUFM.S14A..03G">Mega Tsunamis of the World Ocean and Their Implication for the Tsunami Hazard Assessment</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Gusiakov, V. K. 2014-12-01 Mega tsunamis are the strongest tsunamigenic events of tectonic origin that are characterized by run-up heights up to 40-50 m measured along a considerable part of the coastline (up to 1000 km). One of the most important features of mega-tsunamis is their ability to cross the entire oceanic basin and to cause an essential damage to its opposite coast. Another important feature is their ability to penetrate into the marginal seas (like the Sea of Okhotsk, the Bering Sea) and cause dangerous water level oscillations along the parts of the coast, which are largely protected by island arcs against the impact of the strongest regional tsunamis. Among all known historical tsunamis (nearly 2250 events during the last 4000 years) they represent only a small fraction (less than 1%) however they are responsible for more than half the total tsunami fatalities and a considerable part of the overall tsunami damage. The source of all known mega tsunamis is subduction submarine earthquakes with magnitude 9.0 or higher having a return period from 200-300 years to 1000-1200 years. The paper presents a list of 15 mega tsunami events identified so far in historical catalogs with their basic source parameters, near-field and far-field impact effects and their generation and propagation features. The far-field impact of mega tsunamis is largely controlled by location and orientation of their earthquake source as well as by deep ocean bathymetry features. We also discuss the problem of the long-term tsunami hazard assessment when the occurrence of mega tsunamis is taken into account. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017EGUGA..1911503H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017EGUGA..1911503H">Numerical tsunami simulations in the western Pacific Ocean and East China Sea from hypothetical M 9 earthquakes along the Nankai trough</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Harada, Tomoya; Satake, Kenji; Furumura, Takashi 2017-04-01 We carried out tsunami numerical simulations in the western Pacific Ocean and East China Sea in order to examine the behavior of massive tsunami outside Japan from the hypothetical M 9 tsunami source models along the Nankai Trough proposed by the Cabinet Office of Japanese government (2012). The distribution of MTHs (maximum tsunami heights for 24 h after the earthquakes) on the east coast of China, the east coast of the Philippine Islands, and north coast of the New Guinea Island show peaks with approximately 1.0-1.7 m，4.0-7.0 m，4.0-5.0 m, respectively. They are significantly higher than that from the 1707 Ho'ei earthquake (M 8.7), the largest earthquake along the Nankai trough in recent Japanese history. Moreover, the MTH distributions vary with the location of the huge slip(s) in the tsunami source models although the three coasts are far from the Nankai trough. Huge slip(s) in the Nankai segment mainly contributes to the MTHs, while huge slip(s) or splay faulting in the Tokai segment hardly affects the MTHs. The tsunami source model was developed for responding to the unexpected occurrence of the 2011 Tohoku Earthquake, with 11 models along the Nanakai trough, and simulated MTHs along the Pacific coasts of the western Japan from these models exceed 10 m, with a maximum height of 34.4 m. Tsunami propagation was computed by the finite-difference method of the non-liner long-wave equations with the Corioli's force and bottom friction (Satake, 1995) in the area of 115-155 ° E and 8° S-40° N. Because water depth of the East China Sea is shallower than 200 m, the tsunami propagation is likely to be affected by the ocean bottom fiction. The 30 arc-seconds gridded bathymetry data provided by the General Bathymetric Chart of the Oceans (GEBCO-2014) are used. For long propagation of tsunami we simulated tsunamis for 24 hours after the earthquakes. This study was supported by the"New disaster mitigation research project on Mega thrust earthquakes around Nankai </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016PApGe.173.4089V','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016PApGe.173.4089V">The New Method of Tsunami Source Reconstruction With r-Solution Inversion Method</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Voronina, T. A.; Romanenko, A. A. 2016-12-01 Application of the r-solution method to reconstructing the initial tsunami waveform is discussed. This methodology is based on the inversion of remote measurements of water-level data. The wave propagation is considered within the scope of a linear shallow-water theory. The ill-posed inverse problem in question is regularized by means of a least square inversion using the truncated Singular Value Decomposition method. As a result of the numerical process, an r-solution is obtained. The method proposed allows one to control the instability of a numerical solution and to obtain an acceptable result in spite of ill posedness of the problem. Implementation of this methodology to reconstructing of the initial waveform to 2013 Solomon Islands tsunami validates the theoretical conclusion for synthetic data and a model tsunami source: the inversion result strongly depends on data noisiness, the azimuthal and temporal coverage of recording stations with respect to the source area. Furthermore, it is possible to make a preliminary selection of the most informative set of the available recording stations used in the inversion process. </li> <li> <a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/21389149-plasma-control-modification-helicon-wave-propagation-low-magnetic-fields','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/21389149-plasma-control-modification-helicon-wave-propagation-low-magnetic-fields">Plasma control by modification of helicon wave propagation in low magnetic fields</a> <a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a> Lafleur, T.; Charles, C.; Boswell, R. W. 2010-07-15 By making use of nonuniform magnetic fields, it is shown experimentally that control of helicon wave propagation can be achieved in a low pressure (0.08 Pa) expanding plasma. The m=1 helicon waves are formed during a direct capacitive to wave mode transition that occurs in a low diverging magnetic field (B{sub 0}<3 mT). In this initial configuration, waves are prevented from reaching the downstream region, but slight modifications to the magnetic field allows the axial distance over which waves can propagate to be controlled. By changing the effective propagation distance in this way, significant modification of the density and plasmamore » potential profiles can be achieved, showing that the rf power deposition can be spatially controlled as well. Critical to the modification of the wave propagation behavior is the magnetic field strength (and geometry) near the exit of the plasma source region, which gives electron cyclotron frequencies close to the wave frequency of 13.56 MHz.« less </li> <li> <a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70037131','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70037131">Tsunamis and splay fault dynamics</a> <a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a> Wendt, J.; Oglesby, D.D.; Geist, E.L. 2009-01-01 The geometry of a fault system can have significant effects on tsunami generation, but most tsunami models to date have not investigated the dynamic processes that determine which path rupture will take in a complex fault system. To gain insight into this problem, we use the 3D finite element method to model the dynamics of a plate boundary/splay fault system. We use the resulting ground deformation as a time-dependent boundary condition for a 2D shallow-water hydrodynamic tsunami calculation. We find that if me stress distribution is homogeneous, rupture remains on the plate boundary thrust. When a barrier is introduced along the strike of the plate boundary thrust, rupture propagates to the splay faults, and produces a significantly larger tsunami man in the homogeneous case. The results have implications for the dynamics of megathrust earthquakes, and also suggest mat dynamic earthquake modeling may be a useful tool in tsunami researcn. Copyright 2009 by the American Geophysical Union. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014EGUGA..16.5296K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014EGUGA..16.5296K">Numerical reconstruction of tsunami source using combined seismic, satellite and DART data</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Krivorotko, Olga; Kabanikhin, Sergey; Marinin, Igor 2014-05-01 Recent tsunamis, for instance, in Japan (2011), in Sumatra (2004), and at the Indian coast (2004) showed that a system of producing exact and timely information about tsunamis is of a vital importance. Numerical simulation is an effective instrument for providing such information. Bottom relief characteristics and the initial perturbation data (a tsunami source) are required for the direct simulation of tsunamis. The seismic data about the source are usually obtained in a few tens of minutes after an event has occurred (the seismic waves velocity being about five hundred kilometres per minute, while the velocity of tsunami waves is less than twelve kilometres per minute). A difference in the arrival times of seismic and tsunami waves can be used when operationally refining the tsunami source parameters and modelling expected tsunami wave height on the shore. The most suitable physical models related to the tsunamis simulation are based on the shallow water equations. The problem of identification parameters of a tsunami source using additional measurements of a passing wave is called inverse tsunami problem. We investigate three different inverse problems of determining a tsunami source using three different additional data: Deep-ocean Assessment and Reporting of Tsunamis (DART) measurements, satellite wave-form images and seismic data. These problems are severely ill-posed. We apply regularization techniques to control the degree of ill-posedness such as Fourier expansion, truncated singular value decomposition, numerical regularization. The algorithm of selecting the truncated number of singular values of an inverse problem operator which is agreed with the error level in measured data is described and analyzed. In numerical experiment we used gradient methods (Landweber iteration and conjugate gradient method) for solving inverse tsunami problems. Gradient methods are based on minimizing the corresponding misfit function. To calculate the gradient of the misfit </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017SPIE10214E..11G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017SPIE10214E..11G">Analysis of pulse thermography using similarities between wave and diffusion propagation</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Gershenson, M. 2017-05-01 Pulse thermography or thermal wave imaging are commonly used as nondestructive evaluation (NDE) method. While the technical aspect has evolve with time, theoretical interpretation is lagging. Interpretation is still using curved fitting on a log log scale. A new approach based directly on the governing differential equation is introduced. By using relationships between wave propagation and the diffusive propagation of thermal excitation, it is shown that one can transform from solutions in one type of propagation to the other. The method is based on the similarities between the Laplace transforms of the diffusion equation and the wave equation. For diffusive propagation we have the Laplace variable s to the first power, while for the wave propagation similar equations occur with s2. For discrete time the transformation between the domains is performed by multiplying the temperature data vector by a matrix. The transform is local. The performance of the techniques is tested on synthetic data. The application of common back projection techniques used in the processing of wave data is also demonstrated. The combined use of the transform and back projection makes it possible to improve both depth and lateral resolution of transient thermography. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFMNH21D..04K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFMNH21D..04K">Coastal Tsunami and Risk Assessment for Eastern Mediterranean Countries</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Kentel, E.; Yavuz, C. 2017-12-01 Tsunamis are rarely experienced events that have enormous potential to cause large economic destruction on the critical infrastructures and facilities, social devastation due to mass casualty, and environmental adverse effects like erosion, accumulation and inundation. Especially for the past two decades, nations have encountered devastating tsunami events. The aim of this study is to investigate risks along the Mediterranean coastline due to probable tsunamis based on simulations using reliable historical data. In order to do this, 50 Critical Regions, CRs, (i.e. city centers, agricultural areas and summer villages) and 43 Critical Infrastructures, CIs, (i.e. airports, ports & marinas and industrial structures) are determined to perform people-centered risk assessment along Eastern Mediterranean region covering 7 countries. These countries include Turkey, Syria, Lebanon, Israel, Egypt, Cyprus, and Libya. Bathymetry of the region is given in Figure 1. In this study, NAMI-DANCE is used to carry out tsunami simulations. Source of a sample tsunami simulation and maximum wave propagation in the study area for this sample tsunami are given in Figures 2 and 3, respectively.Richter magnitude,, focal depth, time of occurrence in a day and season are considered as the independent parameters of the earthquake. Historical earthquakes are used to generate reliable probability distributions for these parameters. Monte Carlo (MC) Simulations are carried out to evaluate overall risks at the coastline. Inundation level, population density, number of passenger or employee, literacy rate, annually income level and existence of human are used in risk estimations. Within each MC simulation and for each grid in the study area, people-centered tsunami risk for each of the following elements at risk is calculated: i. City centers ii. Agricultural areas iii. Summer villages iv. Ports and marinas v. Airports vi. Industrial structures Risk levels at each grid along the shoreline are </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013EOSTr..94R.297L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013EOSTr..94R.297L">Landslides Cause Tsunami Waves: Insights From Aysén Fjord, Chile</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Lastras, Galderic; Amblas, David; Calafat, Antoni M.; Canals, Miquel; Frigola, Jaime; Hermanns, Reginald L.; Lafuerza, Sara; Longva, Oddvar; Micallef, Aaron; Sepúlveda, Sergio A.; Vargas, Gabriel; Batist, Marc De; Daele, Maarten Van; Azpiroz, María.; Bascuñán, Ignacio; Duhart, Paul; Iglesias, Olaia; Kempf, Philipp; Rayo, Xavier 2013-08-01 On 21 April 2007, an Mw 6.2 earthquake produced an unforeseen chain of events in the Aysén fjord (Chilean Patagonia, 45.5°S). The earthquake triggered hundreds of subaerial landslides along the fjord flanks. Some of the landslides eventually involved a subaqueous component that, in turn, generated a series of displacement waves—tsunami-like waves produced by the fast entry of a subaerial landmass into a water body—within the fjord [Naranjo et al., 2009; Sepúlveda and Serey, 2009; Hermanns et al., 2013]. These waves, with run-ups several meters high along the shoreline, caused 10 fatalities. In addition, they severely damaged salmon farms, which constitute the main economic activity in the region, setting free millions of cultivated salmon with still unknown ecological consequences. </li> <li> <a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2722927','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2722927">Surface Current Density Mapping for Identification of Gastric Slow Wave Propagation</a> <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a> Bradshaw, L. A.; Cheng, L. K.; Richards, W. O.; Pullan, A. J. 2009-01-01 The magnetogastrogram records clinically relevant parameters of the electrical slow wave of the stomach noninvasively. Besides slow wave frequency, gastric slow wave propagation velocity is a potentially useful clinical indicator of the state of health of gastric tissue, but it is a difficult parameter to determine from noninvasive bioelectric or biomagnetic measurements. We present a method for computing the surface current density (SCD) from multichannel magnetogastrogram recordings that allows computation of the propagation velocity of the gastric slow wave. A moving dipole source model with hypothetical as well as realistic biomagnetometer parameters demonstrates that while a relatively sparse array of magnetometer sensors is sufficient to compute a single average propagation velocity, more detailed information about spatial variations in propagation velocity requires higher density magnetometer arrays. Finally, the method is validated with simultaneous MGG and serosal EMG measurements in a porcine subject. PMID:19403355 </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AGUFMSH21D2561G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUFMSH21D2561G">Obliquely Propagating Waves in Bi-Kappa Plasmas</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Gaelzer, R.; Ziebell, L. F.; Meneses, A. R. 2016-12-01 The effects of kappa velocity distribution functions (VDFs) have been the subjectof intense research. Such functions have beenfound to provide a better fitting to the VDFs measured by spacecraftin the solar wind. An anisotropic VDF contains free energy that can excite wavesin the plasma. The induced turbulence also determines the observed shape of the VDF.The general treatment for waves excited by (bi-)Maxwellian plasmas is well-established.However, for kappa distributions (isotropic or anisotropic), the majority of the studieswere restricted to the limiting cases of purely parallel or perpendicular propagation.Contributions to the general case of obliquely-propagating waves have been scarcely reported.The absence of a general treatment prevents a complete analysis of the wave-particle interactionin kappa plasmas, since some instabilities can operate both in the parallel and oblique directions.A series of papers published by the authors begin to remedy this situation. In a first work [1],we have obtained the dielectric tensor and dispersion relations for quasi-perpendicular dispersive Alfvén waves resulting from a kappa VDF. This approach was later generalized by [2],where the formalism was extended to the general case of electrostatic/electromagnetic waves propagatingin an isotropic kappa plasma in any frequency range and for arbitrary angles.In the present work [3], we generalize even further the formalism by the derivation of thegeneral dielectric tensor of an anisotropic bi-kappa plasma. We present the state-of-the-art of theformalism and show how it enables a systematic study of waves and instabilities propagating inarbitrary directions and frequencies in a bi-kappa plasma.[1] R. Gaelzer, L. F. Ziebell, J. Geophys. Res. 119, 9334 (2014), doi: 10.1002/2014JA020667.[2] R. Gaelzer, L. F. Ziebell, Phys. Plasmas 23, 022110 (2016), doi: 10.1063/1.4941260.[3] R. Gaelzer et al., Phys. Plasmas 23, 062108 (2016), doi: 10.1063/1.4953430. </li> <li> <a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/7199622-nonlinear-wave-equation-nonadiabatic-flame-propagation','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/7199622-nonlinear-wave-equation-nonadiabatic-flame-propagation">A nonlinear wave equation in nonadiabatic flame propagation</a> <a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a> Booty, M.R.; Matalon, M.; Matkowsky, B.J. 1988-06-01 The authors derive a nonlinear wave equation from the diffusional thermal model of gaseous combustion to describe the evolution of a flame front. The equation arises as a long wave theory, for values of the volumeric heat loss in a neighborhood of the extinction point (beyond which planar uniformly propagating flames cease to exist), and for Lewis numbers near the critical value beyond which uniformly propagating planar flames lose stability via a degenerate Hopf bifurcation. Analysis of the equation suggests the possibility of a singularity developing in finite time. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2005AGUFM.T31C..06D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2005AGUFM.T31C..06D">Historic Tsunami in the Indian Ocean</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Dominey-Howes, D.; Cummins, P. R.; Burbidge, D. 2005-12-01 The 2004 Boxing Day Tsunami dramatically highlighted the need for a better understanding of the tsunami hazard in the Indian Ocean. One of the most important foundations on which to base such an assessment is knowledge of tsunami that have affected the region in the historical past. We present a summary of the previously published catalog of Indian Ocean tsunami and the results of a preliminary search of archival material held at the India Records Office at the British Library in London. We demonstrate that in some cases, normal tidal movements and floods associated with tropical cyclones have been erroneously listed as tsunami. We summarise interesting archival material for tsunami that occurred in 1945, 1941, 1881, 1819, 1762 and a tsunami in 1843 not previously identified or reported. We also note the recent discovery, by a Canadian team during a post-tsunami survey following the 2004 Boxing Day Tsunami, of archival evidence that the Great Sumatra Earthquake of 1833 generated a teletsunami. Open ocean wave heights are calculated for some of the historical tsunami and compared with those of the Boxing Day Tsunami. </li> <li> <a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3777432','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3777432">A k-Space Method for Moderately Nonlinear Wave Propagation</a> <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a> Jing, Yun; Wang, Tianren; Clement, Greg T. 2013-01-01 A k-space method for moderately nonlinear wave propagation in absorptive media is presented. The Westervelt equation is first transferred into k-space via Fourier transformation, and is solved by a modified wave-vector time-domain scheme. The present approach is not limited to forward propagation or parabolic approximation. One- and two-dimensional problems are investigated to verify the method by comparing results to analytic solutions and finite-difference time-domain (FDTD) method. It is found that to obtain accurate results in homogeneous media, the grid size can be as little as two points per wavelength, and for a moderately nonlinear problem, the Courant–Friedrichs–Lewy number can be as large as 0.4. Through comparisons with the conventional FDTD method, the k-space method for nonlinear wave propagation is shown here to be computationally more efficient and accurate. The k-space method is then employed to study three-dimensional nonlinear wave propagation through the skull, which shows that a relatively accurate focusing can be achieved in the brain at a high frequency by sending a low frequency from the transducer. Finally, implementations of the k-space method using a single graphics processing unit shows that it required about one-seventh the computation time of a single-core CPU calculation. PMID:22899114 </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li class="active">19</li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> </div> <div id="page_20" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li class="active">20</li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="381"> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016JTePh..61.1765V','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016JTePh..61.1765V">Modeling the propagation of electromagnetic waves over the surface of the human body</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Vendik, I. B.; Vendik, O. G.; Kirillov, V. V.; Pleskachev, V. V.; Tural'chuk, P. A. 2016-12-01 The results of modeling and an experimental study of electromagnetic (EM) waves in microwave range propagating along the surface of the human body have been presented. The parameters of wave propagation, such as the attenuation and phase velocity, have also been investigated. The calculation of the propagation of EM waves by the numerical method FDTD (finite difference time domain), as well as the use of the analytical model of the propagation of the EM wave along flat and curved surfaces has been fulfilled. An experimental study on a human body has been conducted. It has been shown that creeping waves are slow and exhibit a noticeable dispersion, while the surface waves are dispersionless and propagate at the speed of light in free space. A comparison of the results of numerical simulation, analytical calculation, and experimental investigations at a frequency of 2.55 GHz has been carried out. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AGUFM.S21A4412H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AGUFM.S21A4412H">Web-based Tsunami Early Warning System with instant Tsunami Propagation Calculations in the GPU Cloud</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Hammitzsch, M.; Spazier, J.; Reißland, S. 2014-12-01 Usually, tsunami early warning and mitigation systems (TWS or TEWS) are based on several software components deployed in a client-server based infrastructure. The vast majority of systems importantly include desktop-based clients with a graphical user interface (GUI) for the operators in early warning centers. However, in times of cloud computing and ubiquitous computing the use of concepts and paradigms, introduced by continuously evolving approaches in information and communications technology (ICT), have to be considered even for early warning systems (EWS). Based on the experiences and the knowledge gained in three research projects - 'German Indonesian Tsunami Early Warning System' (GITEWS), 'Distant Early Warning System' (DEWS), and 'Collaborative, Complex, and Critical Decision-Support in Evolving Crises' (TRIDEC) - new technologies are exploited to implement a cloud-based and web-based prototype to open up new prospects for EWS. This prototype, named 'TRIDEC Cloud', merges several complementary external and in-house cloud-based services into one platform for automated background computation with graphics processing units (GPU), for web-mapping of hazard specific geospatial data, and for serving relevant functionality to handle, share, and communicate threat specific information in a collaborative and distributed environment. The prototype in its current version addresses tsunami early warning and mitigation. The integration of GPU accelerated tsunami simulation computations have been an integral part of this prototype to foster early warning with on-demand tsunami predictions based on actual source parameters. However, the platform is meant for researchers around the world to make use of the cloud-based GPU computation to analyze other types of geohazards and natural hazards and react upon the computed situation picture with a web-based GUI in a web browser at remote sites. The current website is an early alpha version for demonstration purposes to give the </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009AGUFM.U21E2184W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009AGUFM.U21E2184W">Role of State Tsunami Geoscientists during Emergency Response Activities: Example from the State of California (USA) during September 29, 2009, Samoa Tsunami Event</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Wilson, R. I.; Dengler, L. A.; Goltz, J. D.; Legg, M.; Miller, K. M.; Parrish, J. G.; Whitmore, P. 2009-12-01 California tsunami geoscientists work closely with federal, state and local government emergency managers to help prepare coastal communities for potential impacts from a tsunami before, during, and after an event. For teletsunamis, as scientific information (forecast model wave heights, first-wave arrival times, etc.) from NOAA’s West Coast and Alaska’s Tsunami Warning Center is made available, state-level emergency managers must help convey this information in a concise and comprehendible manner to local officials who ultimately determine the appropriate response activities for their jurisdictions. During the Samoa Tsunami Advisory for California on September 29, 2009, geoscientists from the California Geological Survey and Humboldt State University assisted the California Emergency Management Agency in this information transfer by providing technical assistance during teleconference meetings with NOAA and other state and local emergency managers prior to the arrival of the tsunami. State geoscientists gathered additional background information on anticipated tidal conditions and wave heights for areas not covered by NOAA’s forecast models. The participation of the state geoscientists in the emergency response process resulted in clarifying which regions were potentially at-risk, as well as those having a low risk from the tsunami. Future tsunami response activities for state geoscientists include: 1) working closely with NOAA to simplify their tsunami alert messaging and expand their forecast modeling coverage, 2) creation of “playbooks” containing information from existing tsunami scenarios for local emergency managers to reference during an event, and 3) development of a state-level information “clearinghouse” and pre-tsunami field response team to assist local officials as well as observe and report tsunami effects. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1995ApOpt..34.2089C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1995ApOpt..34.2089C">Simulation of wave propagation in three-dimensional random media</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Coles, Wm. A.; Filice, J. P.; Frehlich, R. G.; Yadlowsky, M. 1995-04-01 Quantitative error analyses for the simulation of wave propagation in three-dimensional random media, when narrow angular scattering is assumed, are presented for plane-wave and spherical-wave geometry. This includes the errors that result from finite grid size, finite simulation dimensions, and the separation of the two-dimensional screens along the propagation direction. Simple error scalings are determined for power-law spectra of the random refractive indices of the media. The effects of a finite inner scale are also considered. The spatial spectra of the intensity errors are calculated and compared with the spatial spectra of </li> <li> <a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70036867','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70036867">The 25 October 2010 Mentawai tsunami earthquake, from real-time discriminants, finite-fault rupture, and tsunami excitation</a> <a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a> Newman, A.V.; Hayes, G.; Wei, Y.; Convers, J. 2011-01-01 The moment magnitude 7.8 earthquake that struck offshore the Mentawai islands in western Indonesia on 25 October 2010 created a locally large tsunami that caused more than 400 human causalities. We identify this earthquake as a rare slow-source tsunami earthquake based on: 1) disproportionately large tsunami waves; 2) excessive rupture duration near 125 s; 3) predominantly shallow, near-trench slip determined through finite-fault modeling; and 4) deficiencies in energy-to-moment and energy-to-duration-cubed ratios, the latter in near-real time. We detail the real-time solutions that identified the slow-nature of this event, and evaluate how regional reductions in crustal rigidity along the shallow trench as determined by reduced rupture velocity contributed to increased slip, causing the 5-9 m local tsunami runup and observed transoceanic wave heights observed 1600 km to the southeast. Copyright 2011 by the American Geophysical Union. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012EGUGA..14.2242G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012EGUGA..14.2242G">Tsunami hazard and risk assessment in El Salvador</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> González, M.; González-Riancho, P.; Gutiérrez, O. Q.; García-Aguilar, O.; Aniel-Quiroga, I.; Aguirre, I.; Alvarez, J. A.; Gavidia, F.; Jaimes, I.; Larreynaga, J. A. 2012-04-01 Tsunamis are relatively infrequent phenomena representing a greater threat than earthquakes, hurricanes and tornadoes, causing the loss of thousands of human lives and extensive damage to coastal infrastructure around the world. Several works have attempted to study these phenomena in order to understand their origin, causes, evolution, consequences, and magnitude of their damages, to finally propose mechanisms to protect coastal societies. Advances in the understanding and prediction of tsunami impacts allow the development of adaptation and mitigation strategies to reduce risk on coastal areas. This work -Tsunami Hazard and Risk Assessment in El Salvador-, funded by AECID during the period 2009-12, examines the state of the art and presents a comprehensive methodology for assessing the risk of tsunamis at any coastal area worldwide and applying it to the coast of El Salvador. The conceptual framework is based on the definition of Risk as the probability of harmful consequences or expected losses resulting from a given hazard to a given element at danger or peril, over a specified time period (European Commission, Schneiderbauer et al., 2004). The HAZARD assessment (Phase I of the project) is based on propagation models for earthquake-generated tsunamis, developed through the characterization of tsunamigenic sources -sismotectonic faults- and other dynamics under study -tsunami waves, sea level, etc.-. The study area is located in a high seismic activity area and has been hit by 11 tsunamis between 1859 and 1997, nine of them recorded in the twentieth century and all generated by earthquakes. Simulations of historical and potential tsunamis with greater or lesser affection to the country's coast have been performed, including distant sources, intermediate and close. Deterministic analyses of the threats under study -coastal flooding- have been carried out, resulting in different hazard maps (maximum wave height elevation, maximum water depth, minimum tsunami </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2006ihy..workE..42D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2006ihy..workE..42D">Propagation and Dissipation of MHD Waves in Coronal Holes</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Dwivedi, B. N. 2006-11-01 bholadwivedi@gmail.com In view of the landmark result on the solar wind outflow, starting between 5 Mm and 20 Mm above the photosphere in magnetic funnels, we investigate the propagation and dissipation of MHD waves in coronal holes. We underline the importance of Alfvén wave dissipation in the magnetic funnels through the viscous and resistive plasma. Our results show that Alfvén waves are one of the primary energy sources in the innermost part of coronal holes where the solar wind outflow starts. We also consider compressive viscosity and thermal conductivity to study the propagation and dissipation of long period slow longitudinal MHD waves in polar coronal holes. We discuss their likely role in the line profile narrowing, and in the energy budget for coronal holes and the solar wind. We compare the contribution of longitudinal MHD waves with high frequency Alfvén waves. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2001AGUFM.S52A0617D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2001AGUFM.S52A0617D">Impacts of the June 23, 2001 Peru Tsunami</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Dengler, L. 2001-12-01 The tsunami generated by the June 23, 2001 Peru earthquake caused significant damage to a 20-km long stretch of coastline in the Municipality of Camana, southern Peru. Over 3000 structures were damaged or destroyed and 2000 hectares of farmland flooded and covered with sand. 22 people were killed in the Municipality and 62 were reported missing. All of the casualties were attributed to the tsunami; in Camana the earthquake produced Modified Mercalli Intensities only of VI or VII. The International Tsunami Survey Team (ITST) were in Peru July 5 - 15 and measured inundation, spoke with City, Red Cross, and Health Department officials, and interviewed survivors. The preliminary ITST findings: All eyewitnesses described an initial draw-down that lasted a substantial amount of time (15 minutes or more). The initial positive wave was small, followed by two destructive waves of near similar impact. Observing the water recede was the key to self-evacuation. No one responded to the ground shaking even though all felt the earthquake strongly. Damage was concentrated along a flat coastal beach no higher than 5 m above sea level. The largest waves (5 to 8 meters) produced by this tsunami coincided with the most developed beach area along the southern Peruvian coast. Tsunami waves penetrated 1.2-km inland and damaged or destroyed nearly all of the structures in this zone. Poorly built adobe and infilled wall structures performed very poorly in the tsunami impacted area. The few structures that survived appeared to have deeper foundations and more reinforcing. The most tsunami-vulnerable populations were newcomers to the coast. Most victims were farm workers and domestic summerhouse sitters who had not grown up along the coast and were unaware of tsunami hazards. Economic impacts are likely to last a long time. The main industries in Camana are tourism and agriculture and the tsunami damaged both. While the extent of inundation and the number of structures damaged or destroyed </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013OcDyn..63.1213P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013OcDyn..63.1213P">Forecasting tsunamis in Poverty Bay, New Zealand, with deep-ocean gauges</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Power, William; Tolkova, Elena 2013-12-01 The response/transfer function of a coastal site to a remote open-ocean point is introduced, with the intent to directly convert open-ocean measurements into the wave time history at the site. We show that the tsunami wave at the site can be predicted as the wave is measured in the open ocean as far as 1,000+ km away from the site, with a straightforward computation which can be performed almost instantaneously. The suggested formalism is demonstrated for the purpose of tsunami forecasting in Poverty Bay, in the Gisborne region of New Zealand. Directional sensitivity of the site response due to different conditions for the excitation of the shelf and the bay's normal modes is investigated and used to explain tsunami observations. The suggested response function formalism is validated with available records of the 2010 Chilean tsunami at Gisborne tide gauge and at the nearby deep-ocean assessment and reporting of tsunamis (DART) station 54401. The suggested technique is also demonstrated by hindcasting the 2011 Tohoku tsunami and 2012 Haida Gwaii tsunami at Monterey Bay, CA, using an offshore record of each tsunami at DART station 46411. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014EGUGA..16.2584S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014EGUGA..16.2584S">Parallel Processing of Numerical Tsunami Simulations on a High Performance Cluster based on the GDAL Library</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Schroeder, Matthias; Jankowski, Cedric; Hammitzsch, Martin; Wächter, Joachim 2014-05-01 Thousands of numerical tsunami simulations allow the computation of inundation and run-up along the coast for vulnerable areas over the time. A so-called Matching Scenario Database (MSDB) [1] contains this large number of simulations in text file format. In order to visualize these wave propagations the scenarios have to be reprocessed automatically. In the TRIDEC project funded by the seventh Framework Programme of the European Union a Virtual Scenario Database (VSDB) and a Matching Scenario Database (MSDB) were established amongst others by the working group of the University of Bologna (UniBo) [1]. One part of TRIDEC was the developing of a new generation of a Decision Support System (DSS) for tsunami Early Warning Systems (TEWS) [2]. A working group of the GFZ German Research Centre for Geosciences was responsible for developing the Command and Control User Interface (CCUI) as central software application which support operator activities, incident management and message disseminations. For the integration and visualization in the CCUI, the numerical tsunami simulations from MSDB must be converted into the shapefiles format. The usage of shapefiles enables a much easier integration into standard Geographic Information Systems (GIS). Since also the CCUI is based on two widely used open source products (GeoTools library and uDig), whereby the integration of shapefiles is provided by these libraries a priori. In this case, for an example area around the Western Iberian margin several thousand tsunami variations were processed. Due to the mass of data only a program-controlled process was conceivable. In order to optimize the computing efforts and operating time the use of an existing GFZ High Performance Computing Cluster (HPC) had been chosen. Thus, a geospatial software was sought after that is capable for parallel processing. The FOSS tool Geospatial Data Abstraction Library (GDAL/OGR) was used to match the coordinates with the wave heights and generates the </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFMNH14A..02R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFMNH14A..02R">Open-Ocean and Coastal Properties of Recent Major Tsunamis</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Rabinovich, A.; Thomson, R.; Zaytsev, O. 2017-12-01 The properties of six major tsunamis during the period 2009-2015 (2009 Samoa; 2010 Chile; 2011 Tohoku; 2012 Haida Gwaii; 2014 and 2015 Chile) were thoroughly examined using coastal data from British Columbia, the U.S. West Coast and Mexico, and offshore open-ocean DART and NEPTUNE stations. Based on joint spectral analyses of the tsunamis and background noise, we have developed a method to suppress the influence of local topography and to use coastal observations to determine the underlying spectra of tsunami waves in the deep ocean. The "reconstructed" open-ocean tsunami spectra were found to be in close agreement with the actual tsunami spectra evaluated from the analysis of directly measured open-ocean tsunami records. We have further used the spectral estimates to parameterize tsunamis based on their integral open-ocean spectral characteristics. Three key parameters are introduced to describe individual tsunami events: (1) Integral open-ocean energy; (2) Amplification factor (increase of the mean coastal tsunami variance relative to the open-ocean variance); and (3) Tsunami colour, the frequency composition of the open-ocean tsunami waves. In particular, we found that the strongest tsunamis, associated with large source areas (the 2010 Chile and 2011 Tohoku) are "reddish" (indicating the dominance of low-frequency motions), while small-source events (the 2009 Samoa and 2012 Haida Gwaii) are "bluish" (indicating strong prevalence of high-frequency motions). </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFMNH23A0231S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFMNH23A0231S">Tsunami Source Modeling of the 2015 Volcanic Tsunami Earthquake near Torishima, South of Japan</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Sandanbata, O.; Watada, S.; Satake, K.; Fukao, Y.; Sugioka, H.; Ito, A.; Shiobara, H. 2017-12-01 An abnormal earthquake occurred at a submarine volcano named Smith Caldera, near Torishima Island on the Izu-Bonin arc, on May 2, 2015. The earthquake, which hereafter we call "the 2015 Torishima earthquake," has a CLVD-type focal mechanism with a moderate seismic magnitude (M5.7) but generated larger tsunami waves with an observed maximum height of 50 cm at Hachijo Island [JMA, 2015], so that the earthquake can be regarded as a "tsunami earthquake." In the region, similar tsunami earthquakes were observed in 1984, 1996 and 2006, but their physical mechanisms are still not well understood. Tsunami waves generated by the 2015 earthquake were recorded by an array of ocean bottom pressure (OBP) gauges, 100 km northeastern away from the epicenter. The waves initiated with a small downward signal of 0.1 cm and reached peak amplitude (1.5-2.0 cm) of leading upward signals followed by continuous oscillations [Fukao et al., 2016]. For modeling its tsunami source, or sea-surface displacement, we perform tsunami waveform simulations, and compare synthetic and observed waveforms at the OBP gauges. The linear Boussinesq equations are adapted with the tsunami simulation code, JAGURS [Baba et al., 2015]. We first assume a Gaussian-shaped sea-surface uplift of 1.0 m with a source size comparable to Smith Caldera, 6-7 km in diameter. By shifting source location around the caldera, we found the uplift is probably located within the caldera rim, as suggested by Sandanbata et al. [2016]. However, synthetic waves show no initial downward signal that was observed at the OBP gauges. Hence, we add a ring of subsidence surrounding the main uplift, and examine sizes and amplitudes of the main uplift and the subsidence ring. As a result, the model of a main uplift of around 1.0 m with a radius of 4 km surrounded by a ring of small subsidence shows good agreement of synthetic and observed waveforms. The results yield two implications for the deformation process that help us to understanding </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016IJT....37..101G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016IJT....37..101G">Laser-Generated Rayleigh Waves Propagating in Transparent Viscoelastic Adhesive Coating/Metal Substrate Systems</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Guan, Yi-jun; Sun, Hong-xiang; Yuan, Shou-qi; Zhang, Shu-yi; Ge, Yong 2016-10-01 We have established numerical models for simulating laser-generated Rayleigh waves in coating/substrate systems by a finite element method and investigated the propagation characteristics of Rayleigh waves in systems concerning the viscoelasticity and transparency of adhesive coatings. In this way, we have studied the influence of the mechanical properties of the coating, such as the elastic moduli, viscoelastic moduli, coating thickness, transparency, and coating material, on the propagation characteristics of the Rayleigh waves. The results show that the propagation characteristics of the Rayleigh waves can be divided into low- and high-frequency parts. The high-frequency propagation characteristics of the Rayleigh wave are closely related to the properties of the adhesive coating. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017APS..DPPT11056V','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017APS..DPPT11056V">Propagation of radio frequency waves through density fluctuations</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Valvis, S. I.; Papagiannis, P.; Papadopoulos, A.; Hizanidis, K.; Glytsis, E.; Bairaktaris, F.; Zisis, A.; Tigelis, I.; Ram, A. K. 2017-10-01 On their way to the core of a tokamak plasma, radio frequency (RF) waves, excited in the vacuum region, have to propagate through a variety of density fluctuations in the edge region. These fluctuations include coherent structures, like blobs that can be field aligned or not, as well as turbulent and filamentary structures. We have been studying the effect of fluctuations on RF propagation using both theoretical (analytical) and computational models. The theoretical results are being compared with those obtained by two different numerical codes ``a Finite Difference Frequency Domain code and the commercial COMSOL package. For plasmas with arbitrary distribution of coherent and turbulent fluctuations, we have formulated an effective dielectric permittivity of the edge plasma. This permittivity tensor is then used in numerical simulations to study the effect of multi-scale turbulence on RF waves. We not only consider plane waves but also Gaussian beams in the electron cyclotron and lower hybrid range of frequencies. The analytical theory and results from simulations on the propagation of RF waves will be presented. Supported in part by the Hellenic National Programme on Controlled Thermonuclear Fusion associated with the EUROfusion Consortium and by DoE Grant DE-FG02-91ER-54109. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012EGUGA..14...76F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012EGUGA..14...76F">A review of potential tsunami impacts to the Suez Canal</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Finkl, C.; Pelinovsky, E. 2012-04-01 Destructive tsunamis in the eastern Mediterranean and Red seas, induced by earthquakes and/or volcanic activity, pose potential hazards to docked seaport shipping and fixed harbor infrastructure as well as to in-transit international shipping within the Suez Canal. Potential vulnerabilities of the Suez Canal to possible tsunami impacts are reviewed by reference to geological, historical, archaeoseismological, and anecdotal data. Tsunami catalogues and databases compiled by earlier researchers are perused to estimate potential return periods for tsunami events that could affect directly the Suez Canal and its closely associated operational infrastructures. Analysis of these various records indicates a centurial return period, or multiples thereof, for long-wave repetition that could generally affect the Nile Delta. It is estimated that tsunami waves 2 m high would have a breaking length about 5 km down Canal whereas a 10 m wave break would occur about 1 km into the Canal. Should a tsunami strike the eastern flanks of the Nile Delta, it would damage Egypt's maritime infrastructure and multi-national commercial vessels and military ships then using the Canal. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010AGUFM.U13A0013F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010AGUFM.U13A0013F">Tsunamis triggered by the 12 January 2010 Earthquake in Haiti</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Fritz, H. M.; Hillaire, J. V.; Molière, E.; Mohammed, F.; Wei, Y. 2010-12-01 On 12 January 2010 a magnitude Mw 7.0 earthquake occurred 25 km west-southwest of Haiti’s Capital of Port-au-Prince, which resulted in more than 230,000 fatalities. In addition tsunami waves triggered by the earthquake caused at least 3 fatalities at Petit Paradis. Unfortunately, the people of Haiti had neither ancestral knowledge nor educational awareness of tsunami hazards despite the 1946 Dominican Republic tsunami at Hispaniola’s northeast coast. In sharp contrast Sri Lankan UN-soldiers on duty at Jacmel self-evacuated given the memory of the 2004 Indian Ocean tsunami. The International Tsunami Survey Team (ITST) documented flow depths, runup heights, inundation distances, sediment deposition, damage patterns at various scales, and performance of the man-made infrastructure and impact on the natural environment. The 31 January to 7 February 2010 ITST covered the greater Bay of Port-au-Prince and more than 100 km of Hispaniola’s south coast between Pedernales, Dominican Republic and Jacmel, Haiti. The Hispaniola survey data includes more than 20 runup and flow depth measurements. The tsunami impacts peaked with maximum flow depths exceeding 3 m both at Petit Paradis inside the Bay of Grand Goâve located 45 km west-southwest of Port-au-Prince and at Jacmel on Haiti’s south coast. A significant variation in tsunami impact was observed on Hispaniola and tsunami runup of more than 1 m was still observed at Pedernales in the Dominican Republic. Jacmel, which is near the center of the south coast, represents an unfortunate example of a village and harbor that was located for protection from storm waves but is vulnerable to tsunami waves with runup doubling from the entrance to the head of the bay. Inundation and damage was limited to less than 100 m inland at both Jacmel and Petit Paradis. Differences in wave period were documented between the tsunami waves at Petit Paradis and Jacmel. The Petit Paradis tsunami is attributed to a coastal submarine landslide </li> <li> <a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20130008672','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20130008672">Assessing Tsunami Vulnerabilities of Geographies with Shallow Water Equations</a> <a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a> Aras, Rifat; Shen, Yuzhong 2012-01-01 Tsunami preparedness is crucial for saving human lives in case of disasters that involve massive water movement. In this work, we develop a framework for visual assessment of tsunami preparedness of geographies. Shallow water equations (also called Saint Venant equations) are a set of hyperbolic partial differential equations that are derived by depth-integrating the Navier-Stokes equations and provide a great abstraction of water masses that have lower depths compared to their free surface area. Our specific contribution in this study is to use Microsoft's XNA Game Studio to import underwater and shore line geographies, create different tsunami scenarios, and visualize the propagation of the waves and their impact on the shore line geography. Most importantly, we utilized the computational power of graphical processing units (GPUs) as HLSL based shader files and delegated all of the heavy computations to the GPU. Finally, we also conducted a validation study, in which we have tested our model against a controlled shallow water experiment. We believe that such a framework with an easy to use interface that is based on readily available software libraries, which are widely available and easily distributable, would encourage not only researchers, but also educators to showcase ideas. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AGUFMNH43B1834T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUFMNH43B1834T">Seismic probabilistic tsunami hazard: from regional to local analysis and use of geological and historical observations</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Tonini, R.; Lorito, S.; Orefice, S.; Graziani, L.; Brizuela, B.; Smedile, A.; Volpe, M.; Romano, F.; De Martini, P. M.; Maramai, A.; Selva, J.; Piatanesi, A.; Pantosti, D. 2016-12-01 Site-specific probabilistic tsunami hazard analyses demand very high computational efforts that are often reduced by introducing approximations on tsunami sources and/or tsunami modeling. On one hand, the large variability of source parameters implies the definition of a huge number of potential tsunami scenarios, whose omission could easily lead to important bias in the analysis. On the other hand, detailed inundation maps computed by tsunami numerical simulations require very long running time. When tsunami effects are calculated at regional scale, a common practice is to propagate tsunami waves in deep waters (up to 50-100 m depth) neglecting non-linear effects and using coarse bathymetric meshes. Then, maximum wave heights on the coast are empirically extrapolated, saving a significant amount of computational time. However, moving to local scale, such assumptions drop out and tsunami modeling would require much greater computational resources. In this work, we perform a local Seismic Probabilistic Tsunami Hazard Analysis (SPTHA) for the 50 km long coastal segment between Augusta and Siracusa, a touristic and commercial area placed along the South-Eastern Sicily coast, Italy. The procedure consists in using the outcomes of a regional SPTHA as input for a two-step filtering method to select and substantially reduce the number of scenarios contributing to the specific target area. These selected scenarios are modeled using high resolution topo-bathymetry for producing detailed inundation maps. Results are presented as probabilistic hazard curves and maps, with the goal of analyze, compare and highlight the different results provided by regional and local hazard assessments. Moreover, the analysis is enriched by the use of local observed tsunami data, both geological and historical. Indeed, tsunami data-sets available for the selected target areas are particularly rich with respect to the scarce and heterogeneous data-sets usually available elsewhere. Therefore </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013AGUFMSA53A..04Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013AGUFMSA53A..04Z">Tracing Acoustic-Gravity Waves from the Ocean into the Ionosphere</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Zabotin, N. A.; Godin, O. A.; Bullett, T. W.; Negrea, C. 2013-12-01 Ionospheric manifestations of tsunamis provide dramatic evidence of a connection between wave processes in the ocean and in the atmosphere. But tsunamis are only a transient feature of a more general phenomenon, infragravity waves (IGWs). IGWs are permanently present surface gravity waves in the ocean with periods longer than the longest periods (~30 s) of wind-generated waves. IGWs propagate transoceanic distances and, because of their long wavelengths (from ~1 km to hundreds of km), provide a mechanism for coupling wave processes in the ocean, atmosphere, and the solid Earth. The notion that tsunamis may generate waves in the upper atmosphere has existed for a long time but no quantitative coupling theory for the background waves has been proposed. We provide a strict physical justification for the influence of the background IGWs on the upper atmosphere. Taking into account both fluid compressibility and the gravity in a coupled atmosphere-ocean system, we show that there exist two distinct regimes of IGW penetration into the atmosphere. At higher frequencies, one has evanescent waves in the atmosphere propagating horizontally along the ocean surface. At lower frequencies, IGWs continuously radiate their energy into the upper atmosphere in the form of acoustic gravity waves (AGWs). The transition frequency depends on the ocean depth; it varies slowly near 3 mHz for typical depth values and drops to zero sharply only for extremely large depths. Using semi-empirical model of the IGW power spectrum, we derive an estimate of the flux of the mechanical energy and mechanical momentum from the deep ocean into the atmosphere due to background IGWs and predict specific forcing on the atmosphere in coastal regions. We compare spectra of wave processes in the ionosphere measured using Dynasonde technique over Wallops Island, VA and San Juan, PR and interpret the differences in terms of the oceanic effects. We conclude that AGWs of oceanic origin may have an observable </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2003ASAJ..113.2186C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2003ASAJ..113.2186C">Chaos and wave propagation regimes</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Colosi, John 2003-04-01 Ray chaos theory and parabolic equation numerical modeling were two thrusts of Fred Tappert's research that were perpetually in tension. Fred was interested in the problem of identifying wave propagation regimes, most notably the strong focusing caustic regime and its evolution into the saturation regime. On the one hand, chaos theory held the seed of the complexity Fred believed existed in ocean acoustic wavefields; on the other hand ocean acoustic ray chaos theory (which Fred helped to pioneer) was a disdainful approximation to the full wave treatments offered by parabolic equation calculations. Fred was convinced that the saturation limit could not be obtained using ray theory and therefore he examined a new field of inquiry: a blend of chaotic ray insight and full wave dynamics called wave chaos. This talk will discuss some of Fred's insights on this topic and how they relate to observations from basin scale acoustic transmissions. </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li class="active">20</li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> </div> <div id="page_21" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li class="active">21</li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="401"> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013AGUSMNH51A..03M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013AGUSMNH51A..03M">Hydrodynamics of the 1868 and 1877 tsunamis in Southern Peru and Northern Chile</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Morales, S.; Soto-Sandoval, J.; Monardez, P. 2013-05-01 The tsunami occurred on 27th February 2010 offshore central Chile due to a mega-thrust earthquake (Mw=8.8), showed a complex hydrodynamic behavior in the near field that is not completely understood and could not be well characterized using linear models (Cox 2011, Fujima 2011). Several floods separated by several minutes that lasted over eight hours, which flowed parallel to the coast were reported. A reasonable physical explication for this phenomena has been published. Due to the distance from the rupture zone to the coast is shorter than a complete tsunami wave, the latter cannot be created then secondary effects are triggered (Monárdez and Salinas, 2011). This was validated using numerical models based on RANS equations and measurements and field observations in the 2010 Chilean tsunami. Due to this knowledge, the 1868 and 1877 last mega-thrust earthquakes in the Southern Peru and Northern Chile are analyzed. This became necessary, since this zone is known as one the major seismic gap in the area. Scenarios with different fault parameters were implemented for the 1868 and 1877 tsunamis and important results were obtained. In both of the tsunamis, several floods were observed and the arrival time and direction of flow propagation were according to historical reports. In the 1868 tsunami, the effects on the Chilean coast are due to secondary effects such as it is described in historical observations, e.g. in Arica port three main floods 40, 120 and 156 minutes after the earthquakes are observed. In the 1877 tsunami secondary effects were present mainly on the Peruvian coast. Finally, a new classification for near and far field tsunami is proposed. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018RMRE...51.1347N','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018RMRE...51.1347N">Determining the Viscosity Coefficient for Viscoelastic Wave Propagation in Rock Bars</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Niu, Leilei; Zhu, Wancheng; Li, Shaohua; Guan, Kai 2018-05-01 Rocks with microdefects exhibit viscoelastic behavior during stress wave propagation. The viscosity coefficient of the wave can be used to characterize the attenuation as the wave propagates in rock. In this study, a long artificial bar with a readily adjustable viscosity coefficient was fabricated to investigate stress wave attenuation. The viscoelastic behavior of the artificial bar under dynamic loading was investigated, and the initial viscoelastic coefficient was obtained based on the amplitude attenuation of the incident harmonic wave. A one-dimensional wave propagation program was compiled to reproduce the time history of the stress wave measured during the experiments, and the program was well fitted to the Kelvin-Voigt model. The attenuation and dispersion of the stress wave in long artificial viscoelastic bars were quantified to accurately determine the viscoelastic coefficient. Finally, the method used to determine the viscoelastic coefficient of a long artificial bar based on the experiments and numerical simulations was extended to determine the viscoelastic coefficient of a short rock bar. This study provides a new method of determining the viscosity coefficient of rock. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2005AGUSM.U52A..05B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2005AGUSM.U52A..05B">Multi-sensor investigation of the Sumatran Tsunami: observations and analysis of hydroacoustic, seismic, infrasonic, and tide gauge data</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Bhattacharyya, J.; Pulli, J.; Gibson, R.; Upton, Z. 2005-05-01 We present an analysis of the acoustic signals from the December 26, 2004 Sumatra earthquakes, in conjunction with the seismic and tide gauge information from the event. The M9.0 mainshock and its aftershocks were recorded by a suite of seismic sensors around the globe, giving us information on its location and the source process. Recently installed sensor assets in the Indian Ocean have enabled us to study additional features of this significant event. Hydroacoustic signals were recorded by three hydrophone arrays, and the direction finding capability of these arrays allows us to examine the location, time and extent of the T-wave generation process. We detect a clear variation of the back-azimuth that is consistent with the spatial extent of the source rupture. Recordings from nearly co-located seismometers provide insights into the acoustic-to-seismic conversion process for T-waves at islands, along with the variation in signal characteristics with source size. Two separate infrasound arrays detect the atmospheric signals generated by the event, along with additional observations of the seismic surface wave and the T-phase. We will present a comparison of the signals from the mainshock, as a function of location and size, with those from aftershocks and similar events in the nearby region. Our acoustic observations compare favorably with model predictions of wave propagation in the region. For the hydroacoustic data, the azimuth, arrival time, and signal blockage characteristics, from three separate arrays, associate the onset of the signal with the mainshock and with a time extent consistent with the rupture propagation. Our analysis of the T-phase travel times suggests that the seismic-to-acoustic conversion occurs more than 100 km from the epicenter. The infrasound signal's arrival time and signal duration are consistent with both stratospheric and thermospheric propagation from a source region near the mainshock. We use the tide gauge data from stations </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFMNH23A0236S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFMNH23A0236S">Characteristics of Recent Tsunamis</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Sweeney, A. D.; Eble, M. C.; Mungov, G. 2017-12-01 How long do tsunamis impact a coast? How often is the largest tsunami wave the first to arrive? How do measurements in the far field differ from those made close to the source? Extending the study of Eblé et al. (2015) who showed the prevalence of a leading negative phase, we assimilate and summarize characteristics of known tsunami events recorded on bottom pressure and coastal water level stations throughout the world oceans to answer these and other questions. An extensive repository of data from the National Centers for Environmental Information (NCEI) archive for tsunami-ready U.S. tide gauge stations, housing more than 200 sites going back 10 years are utilized as are some of the more 3000 marigrams (analog or paper tide gauge records) for tsunami events. The focus of our study is on five tsunamis generated by earthquakes: 2010 Chile (Maule), 2011 East Japan (Tohoku), 2012 Haida Gwaii, 2014 Chile (Iquique), and 2015 Central Chile and one meteorologically generated tsunami on June 2013 along the U.S. East Coast and Caribbean. Reference: Eblé, M., Mungov, G. & Rabinovich, A. On the Leading Negative Phase of Major 2010-2014 Tsunamis. Pure Appl. Geophys. (2015) 172: 3493. https://doi.org/10.1007/s00024-015-1127-5 </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010AIPC.1253..140M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010AIPC.1253..140M">Laser vibrometry for guided wave propagation phenomena visualisation and damage detection</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Malinowski, Pawel; Wandowski, Tomasz; Kudela, Pawel; Ostachowicz, Wieslaw 2010-05-01 This paper presents research on the damage localization method. The method is based on guided wave propagation phenomena. The investigation was focused on application of this method to monitor the condition of structural elements such as aluminium or composite panels. These elements are commonly used in aerospace industry and it is crucial to provide a methodology to determine their condition, in order to prevent from unexpected and dangerous collapse of a structure. Propagating waves interact with cracks, notches, rivets, thickness changes, stiffeners and other discontinuities present in structural elements. It means that registering these waves one can obtain information about the structure condition—whether it is damaged or not. Furthermore these methods can be applied not only to aerospace structures but also to wind turbine blades and pipelines. In reported investigation piezoelectric transducer was used to excite guided waves in considered panel. Measurement of the wave field was realized using laser scanning vibrometer that registered the velocity responses at a defined points belonging to a defined mesh. Mesh spacing was investigated in order to ensure fine wave propagation visualisation. Firstly, wave propagation in pristine specimen was investigated. Secondly, artificial damage was introduced to the specimen. Finally, wave interaction with damage was visualised and conclusions regarding potentials of application of laser vibrometer for damage detection were drawn. All the processing was made with the developed MATLAB procedures. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AGUFM.S41C4492P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AGUFM.S41C4492P">Determination of source process and the tsunami simulation of the 2013 Santa Cruz earthquake</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Park, S. C.; Lee, J. W.; Park, E.; Kim, S. 2014-12-01 In order to understand the characteristics of large tsunamigenic earthquakes, we analyzed the earthquake source process of the 2013 Santa Cruz earthquake and simulated the following tsunami. We first estimated the fault length of about 200 km using 3-day aftershock distribution and the source duration of about 110 seconds using the duration of high-frequency energy radiation (Hara, 2007). Moment magnitude was estimated to be 8.0 using the formula of Hara (2007). From the results of 200 km of fault length and 110 seconds of source duration, we used the initial value of rupture velocity as 1.8 km/s for teleseismic waveform inversions. Teleseismic body wave inversion was carried out using the inversion package by Kikuchi and Kanamori (1991). Teleseismic P waveform data from 14 stations were used and band-pass filter of 0.005 ~ 1 Hz was applied. Our best-fit solution indicated that the earthquake occurred on the northwesterly striking (strike = 305) and shallowly dipping (dip = 13) fault plane. Focal depth was determined to be 23 km indicating shallow event. Moment magnitude of 7.8 was obtained showing somewhat smaller than the result obtained above and that of previous study (Lay et al., 2013). Large slip area was seen around the hypocenter. Using the slip distribution obtained by teleseismic waveform inversion, we calculated the surface deformations using formulas of Okada (1985) assuming as the initial change of sea water by tsunami. Then tsunami simulation was carred out using Conell Multi-grid Coupled Tsunami Model (COMCOT) code and 1 min-grid topographic data for water depth from the General Bathymetric Chart of the Ocenas (GEBCO). According to the tsunami simulation, most of tsunami waves propagated to the directions of southwest and northeast which are perpendicular to the fault strike. DART buoy data were used to verify our simulation. In the presentation, we will discuss more details on the results of source process and tsunami simulation and compare them </li> <li> <a target="_blank" onclick="trackOutboundLink('http://library.lanl.gov/tsunami/','USGSPUBS'); return false;" href="http://library.lanl.gov/tsunami/">Confirmation and calibration of computer modeling of tsunamis produced by Augustine volcano, Alaska</a> <a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a> Beget, James E.; Kowalik, Zygmunt 2006-01-01 Numerical modeling has been used to calculate the characteristics of a tsunami generated by a landslide into Cook Inlet from Augustine Volcano. The modeling predicts travel times of ca. 50-75 minutes to the nearest populated areas, and indicates that significant wave amplification occurs near Mt. Iliamna on the western side of Cook Inlet, and near the Nanwelak and the Homer-Anchor Point areas on the east side of Cook Inlet. Augustine volcano last produced a tsunami during an eruption in 1883, and field evidence of the extent and height of the 1883 tsunamis can be used to test and constrain the results of the computer modeling. Tsunami deposits on Augustine Island indicate waves near the landslide source were more than 19 m high, while 1883 tsunami deposits in distal sites record waves 6-8 m high. Paleotsunami deposits were found at sites along the coast near Mt. Iliamna, Nanwelak, and Homer, consistent with numerical modeling indicating significant tsunami wave amplification occurs in these areas. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2002cosp...34E2976E','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2002cosp...34E2976E">Tsunami process: From upper mantle to atmosphere</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Ershov, S.; Mikhaylovskaya, I.; Novik, O. Earthquakes in near sea regions and/or tsunamis are manifestations of powerful geodynamic processes beneath the Ocean floor (75 % of the Earth' surface). An effective monitoring of these large-scale processes is not possible without satellites as well as without understanding of physical nature of signals accompanying these processes, e.g. connection between parameters of a seismic excitation in ocean lithosphere and electromagnetic (EM) signals in atmosphere. Basing on the theory of elasticity, electrodynamics, fluid dynamics and geophysical data we formulate a nonlinear mathematical model of generation and propagation of seismo-EM signals in the basin of a marginal sea including transfer of seismic and EM energy from upper mantle to hydrosphere and EM emission into atmosphere up to ionosphere domain D. For a model basin approximately similar to the central part of the Sea of Japan, we calculate signals caused by moderate elastic displacements (EDs): the ampl of a few cm, the main freq. 0.01-10 Hz and duration up to 10 sec (by runs with different acceptable data) which are supposed to be arising at the moment t=0 at the bottom of the upper mantle layer M. The EM signal appears near the bottom of the conductive (0.02 S/m) layer M and reaches for the sea bottom by t=3.5 sec with the ampl. Of 50 pT. This signal propagate in sea water (4 S/m) rather slowly and seems to be "frozen": its front is located near the sea bottom and is replicating the bottom's configuration up to the moment (t=5.2 sec) of the seismic P wave (from M) arrival at the sea bottom. The EM field is generated in seismically disturbed sea water in presence of the geomagnetic field" a specific structure of a seismo-hydrodynamic flow, a spatial break of the diffusive magnetic field, joining of its contours, and other details of the seismo-hydro-EM tsunami process are shown to clear out the out the physical nature of its signals. By the moderate EDs (above), the magnetic signal (freq. 0.01-10 Hz, i </li> <li> <a target="_blank" onclick="trackOutboundLink('https://eosweb.larc.nasa.gov/project/misr/gallery/tsunami_sri_lanka','SCIGOV-ASDC'); return false;" href="https://eosweb.larc.nasa.gov/project/misr/gallery/tsunami_sri_lanka">Tsunami: Sri Lanka</a> <a target="_blank" href="http://eosweb.larc.nasa.gov/">Atmospheric Science Data Center </a> 2013-04-16 ... View Larger Image The initial tsunami waves resulting from the undersea earthquake ... ITSS/Jet Propulsion Laboratory); Michael Garay and David J. Diner (Jet Propulsion Laboratory, California Institute of Technology); and ... </li> <li> <a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20150008554&hterms=foster&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAuthor-Name%26N%3D0%26No%3D40%26Ntt%3Dfoster','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20150008554&hterms=foster&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAuthor-Name%26N%3D0%26No%3D40%26Ntt%3Dfoster">Observing Traveling Ionospheric Disturbances Caused by Tsunamis Using GPS TEC Measurements</a> <a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a> Galvan, David A.; Komjathy, Attila; Hickey, Michael; Foster, James; Mannucci, Anthony J. 2010-01-01 Ground-based Global Positioning System (GPS) measurements of ionospheric Total Electron Content (TEC) show variations consistent with atmospheric internal gravity waves caused by ocean tsunamis following two recent seismic events: the American Samoa earthquake of September 29, 2009, and the Chile earthquake of February 27, 2010. Fluctuations in TEC correlated in time, space, and wave properties with these tsunamis were observed in TEC estimates processed using JPL's Global Ionospheric Mapping Software. These TEC estimates were band-pass filtered to remove ionospheric TEC variations with wavelengths and periods outside the typical range of internal gravity waves caused by tsunamis. Observable variations in TEC appear correlated with the tsunamis in certain locations, but not in others. Where variations are observed, the typical amplitude tends to be on the order of 1% of the background TEC value. Variations with amplitudes 0.1 - 0.2 TECU are observable with periods and timing affiliated with the tsunami. These observations are compared to estimates of expected tsunami-driven TEC variations produced by Embry Riddle Aeronautical University's Spectral Full Wave Model, an atmosphere-ionosphere coupling model, and found to be in good agreement in some locations, though there are cases when the model predicts an observable tsunami-driven signature and none is observed. These TEC variations are not always seen when a tsunami is present, but in these two events the regions where a strong ocean tsunami was observed did coincide with clear TEC observations, while a lack of clear TEC observations coincided with smaller tsunami amplitudes. There exists the potential to apply these detection techniques to real-time GPS TEC data, providing estimates of tsunami speed and amplitude that may be useful for early warning systems. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AGUFMNH43B1841F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUFMNH43B1841F">A consistent model for tsunami actions on buildings</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Foster, A.; Rossetto, T.; Eames, I.; Chandler, I.; Allsop, W. 2016-12-01 The Japan (2011) and Indian Ocean (2004) tsunami resulted in significant loss of life, buildings, and critical infrastructure. The tsunami forces imposed upon structures in coastal regions are initially due to wave slamming, after which the quasi-steady flow of the sea water around buildings becomes important. An essential requirement in both design and loss assessment is a consistent model that can accurately predict these forces. A model suitable for predicting forces in the in the quasi-steady range has been established as part of a systematic programme of research by the UCL EPICentre to understand the fundamental physical processes of tsunami actions on buildings, and more generally their social and economic consequences. Using the pioneering tsunami generator at HR Wallingford, this study considers the influence of unsteady flow conditions on the forces acting upon a rectangular building occupying 10-80% of a channel for 20-240 second wave periods. A mathematical model based upon basic open-channel flow principles is proposed, which provides empirical estimates for drag and hydrostatic coefficients. A simple force prediction equation, requiring only basic flow velocity and wave height inputs is then developed, providing good agreement with the experimental results. The results of this study demonstrate that the unsteady forces from the very long waves encountered during tsunami events can be predicted with a level of accuracy and simplicity suitable for design and risk assessment. </li> <li> <a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20170000013&hterms=tsunami&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dtsunami','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20170000013&hterms=tsunami&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dtsunami">Tsunami Waves Extensively Resurfaced the Shorelines of an Early Martian Ocean</a> <a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a> Rodriguez, J. A. P.; Fairen, A. G.; Linares, R.; Zarroca, M.; Platz, T.; Komatsu, G.; Kargel, J. S.; Gulick, V.; Jianguo, Y.; Higuchi, K.; <a style="text-decoration: none; " href="javascript:void(0); " onClick="displayelement('author_20170000013'); toggleEditAbsImage('author_20170000013_show'); toggleEditAbsImage('author_20170000013_hide'); "> <img style="display:inline; width:12px; height:12px; " src="images/arrow-up.gif" width="12" height="12" border="0" alt="hide" id="author_20170000013_show"> <img style="width:12px; height:12px; display:none; " src="images/arrow-down.gif" width="12" height="12" border="0" alt="hide" id="author_20170000013_hide"> 2016-01-01 Viking image-based mapping of a widespread deposit covering most of the northern low-lands of Mars led to the proposal by Parker et al. that the deposit represents the vestiges of an enormous ocean that existed approx. 3.4 Ga. Later identified as the Vastitas Borealis Formation, the latest geologic map of Mars identifies this deposit as the Late Hesperian lowland unit (lHl). This deposit is typically bounded by raised lobate margins. In addition, some margins have associated rille channels, which could have been produced sub-aerially by the back-wash of high-energy tsunami waves. Radar-sounding data indicate that the deposit is ice-rich. However, until now, the lack of wave-cut shoreline features and the presence of lobate margins have remained an im-pediment to the acceptance of the paleo-ocean hypothesis. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016JaJAP..55gKF01H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016JaJAP..55gKF01H">High resolution wavenumber analysis for investigation of arterial pulse wave propagation</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Hasegawa, Hideyuki; Sato, Masakazu; Irie, Takasuke 2016-07-01 The propagation of the pulse wave along the artery is relatively fast (several m/s), and a high-temporal resolution is required to measure pulse wave velocity (PWV) in a regional segment of the artery. High-frame-rate ultrasound enables the measurement of the regional PWV. In analyses of wave propagation phenomena, the direction and propagation speed are generally identified in the frequency-wavenumber space using the two-dimensional Fourier transform. However, the wavelength of the pulse wave is very long (1 m at a propagation velocity of 10 m/s and a temporal frequency of 10 Hz) compared with a typical lateral field of view of 40 mm in ultrasound imaging. Therefore, PWV cannot be identified in the frequency-wavenumber space owing to the low resolution of the two-dimensional Fourier transform. In the present study, PWV was visualized in the wavenumber domain using phases of arterial wall acceleration waveforms measured by high-frame-rate ultrasound. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009GeoJI.176..589F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009GeoJI.176..589F">Spectral modification of seismic waves propagating through solids exhibiting a resonance frequency: a 1-D coupled wave propagation-oscillation model</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Frehner, Marcel; Schmalholz, Stefan M.; Podladchikov, Yuri 2009-02-01 A 1-D model is presented that couples the microscale oscillations of non-wetting fluid blobs in a partially saturated poroelastic medium with the macroscale wave propagation through the elastic skeleton. The fluid oscillations are caused by surface tension forces that act as the restoring forces driving the oscillations. The oscillations are described mathematically with the equation for a linear oscillator and the wave propagation is described with the 1-D elastic wave equation. Coupling is done using Hamilton's variational principle for continuous systems. The resulting linear system of two partial differential equations is solved numerically with explicit finite differences. Numerical simulations are used to analyse the effect of solids exhibiting internal oscillations, and consequently a resonance frequency, on seismic waves propagating through such media. The phase velocity dispersion relation shows a higher phase velocity in the high-frequency limit and a lower phase velocity in the low-frequency limit. At the resonance frequency a singularity in the dispersion relation occurs. Seismic waves can initiate oscillations of the fluid by transferring energy from solid to fluid at the resonance frequency. Due to this transfer, the spectral amplitude of the solid particle velocity decreases at the resonance frequency. After initiation, the oscillatory movement of the fluid continuously transfers energy at the resonance frequency back to the solid. Therefore, the spectral amplitude of the solid particle velocity is increased at the resonance frequency. Once initiated, fluid oscillations decrease in amplitude with increasing time. Consequently, the spectral peak of the solid particle velocity at the resonance frequency decreases with time. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017PApGe.174.2945C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017PApGe.174.2945C">Numerical Simulations of the 1991 Limón Tsunami, Costa Rica Caribbean Coast</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Chacón-Barrantes, Silvia; Zamora, Natalia 2017-08-01 The second largest recorded tsunami along the Caribbean margin of Central America occurred 25 years ago. On April 22nd, 1991, an earthquake with magnitude Mw 7.6 ruptured along the thrust faults that form the North Panamá Deformed Belt (NPDB). The earthquake triggered a tsunami that affected the Caribbean coast of Costa Rica and Panamá within few minutes, generating two casualties. These are the only deaths caused by a tsunami in Costa Rica. Coseismic uplift up to 1.6 m and runup values larger than 2 m were measured along some coastal sites. Here, we consider three solutions for the seismic source as initial conditions to model the tsunami, each considering a single rupture plane. We performed numerical modeling of the tsunami propagation and runup using NEOWAVE numerical model (Yamazaki et al. in Int J Numer Methods Fluids 67:2081-2107, 2010, doi: 10.1002/fld.2485 ) on a system of nested grids from the entire Caribbean Sea to Limón city. The modeled surface deformation and tsunami runup agreed with the measured data along most of the coastal sites with one preferred model that fits the field data. The model results are useful to determine how the 1991 tsunami could have affected regions where tsunami records were not preserved and to simulate the effects of the coastal surface deformations as buffer to tsunami. We also performed tsunami modeling to simulate the consequences if a similar event with larger magnitude Mw 7.9 occurs offshore the southern Costa Rican Caribbean coast. Such event would generate maximum wave heights of more than 5 m showing that Limón and northwestern Panamá coastal areas are exposed to moderate-to-large tsunamis. These simulations considering historical events and maximum credible scenarios can be useful for hazard assessment and also as part of studies leading to tsunami evacuation maps and mitigation plans, even when that is not the scope of this paper. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2008JGRC..113.1020K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2008JGRC..113.1020K">Kuril Islands tsunami of November 2006: 1. Impact at Crescent City by distant scattering</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Kowalik, Z.; Horrillo, J.; Knight, W.; Logan, Tom 2008-01-01 A numerical model for the global tsunami computation constructed by Kowalik et al. (2005, 2007a) is applied to the tsunami of November 15, 2006 in the northern Pacific with spatial resolution of one minute. Numerical results are compared to sea level data collected by Pacific DART buoys. The tide gauge at Crescent City (CC) recorded an initial tsunami wave of about 20 cm amplitude and a second larger energy packet arriving 2 hours later. The first energy input into the CC harbor was the primary (direct) wave traveling over the deep waters of the North Pacific. Interactions with submarine ridges and numerous seamounts located in the tsunami path were a larger source of tsunami energy than the direct wave. Travel time for these amplified energy fluxes is longer than for the direct wave. Prime sources for the larger fluxes at CC are interactions with Koko Guyot and Hess Rise. Tsunami waves travel next over the Mendocino Escarpment where the tsunami energy flux is concentrated owing to refraction and directed toward CC. Local tsunami amplification over the shelf break and shelf are important as well. In many locations along the North Pacific coast, the first arriving signal or forerunner has lower amplitude than the main signal, which often is delayed. Understanding this temporal distribution is important for an application to tsunami warning and prediction. As a tsunami hazard mitigation tool, we propose that along with the sea level records (which are often quite noisy), an energy flux for prediction of the delayed tsunami signals be used. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016EGUGA..1814477A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016EGUGA..1814477A">Propagation of uncertainties for an evaluation of the Azores-Gibraltar Fracture Zone tsunamigenic potential</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Antoshchenkova, Ekaterina; Imbert, David; Richet, Yann; Bardet, Lise; Duluc, Claire-Marie; Rebour, Vincent; Gailler, Audrey; Hébert, Hélène 2016-04-01 The aim of this study is to assess evaluation the tsunamigenic potential of the Azores-Gibraltar Fracture Zone (AGFZ). This work is part of the French project TANDEM (Tsunamis in the Atlantic and English ChaNnel: Definition of the Effects through numerical Modeling; www-tandem.cea.fr), special attention is paid to French Atlantic coasts. Structurally, the AGFZ region is complex and not well understood. However, a lot of its faults produce earthquakes with significant vertical slip, of a type that can result in tsunami. We use the major tsunami event of the AGFZ on purpose to have a regional estimation of the tsunamigenic potential of this zone. The major reported event for this zone is the 1755 Lisbon event. There are large uncertainties concerning source location and focal mechanism of this earthquake. Hence, simple deterministic approach is not sufficient to cover on the one side the whole AGFZ with its geological complexity and on the other side the lack of information concerning the 1755 Lisbon tsunami. A parametric modeling environment Promethée (promethee.irsn.org/doku.php) was coupled to tsunami simulation software based on shallow water equations with the aim of propagation of uncertainties. Such a statistic point of view allows us to work with multiple hypotheses simultaneously. In our work we introduce the seismic source parameters in a form of distributions, thus giving a data base of thousands of tsunami scenarios and tsunami wave height distributions. Exploring our tsunami scenarios data base we present preliminary results for France. Tsunami wave heights (within one standard deviation of the mean) can be about 0.5 m - 1 m for the Atlantic coast and approaching 0.3 m for the English Channel. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AGUFM.T13D3041E','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AGUFM.T13D3041E">Seismic Wave Propagation on the Tablet Computer</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Emoto, K. 2015-12-01 Tablet computers widely used in recent years. The performance of the tablet computer is improving year by year. Some of them have performance comparable to the personal computer of a few years ago with respect to the calculation speed and the memory size. The convenience and the intuitive operation are the advantage of the tablet computer compared to the desktop PC. I developed the iPad application of the numerical simulation of the seismic wave propagation. The numerical simulation is based on the 2D finite difference method with the staggered-grid scheme. The number of the grid points is 512 x 384 = 196,608. The grid space is 200m in both horizontal and vertical directions. That is the calculation area is 102km x 77km. The time step is 0.01s. In order to reduce the user waiting time, the image of the wave field is drawn simultaneously with the calculation rather than playing the movie after the whole calculation. P and S wave energies are plotted on the screen every 20 steps (0.2s). There is the trade-off between the smooth simulation and the resolution of the wave field image. In the current setting, it takes about 30s to calculate the 10s wave propagation (50 times image updates). The seismogram at the receiver is displayed below of the wave field updated in real time. The default medium structure consists of 3 layers. The layer boundary is defined by 10 movable points with linear interpolation. Users can intuitively change to the arbitrary boundary shape by moving the point. Also users can easily change the source and the receiver positions. The favorite structure can be saved and loaded. For the advance simulation, users can introduce the random velocity fluctuation whose spectrum can be changed to the arbitrary shape. By using this application, everyone can simulate the seismic wave propagation without the special knowledge of the elastic wave equation. So far, the Japanese version of the application is released on the App Store. Now I am preparing the </li> <li> <a target="_blank" onclick="trackOutboundLink('https://eric.ed.gov/?q=mechanical+AND+properties&pg=3&id=EJ860670','ERIC'); return false;" href="https://eric.ed.gov/?q=mechanical+AND+properties&pg=3&id=EJ860670">A Problem-Based Approach to Elastic Wave Propagation: The Role of Constraints</a> <a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a> Fazio, Claudio; Guastella, Ivan; Tarantino, Giovanni 2009-01-01 A problem-based approach to the teaching of mechanical wave propagation, focused on observation and measurement of wave properties in solids and on modelling of these properties, is presented. In particular, some experimental results, originally aimed at measuring the propagation speed of sound waves in metallic rods, are used in order to deepen… </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1995PhDT........11A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1995PhDT........11A">Study of Surface Wave Propagation in Fluid-Saturated Porous Solids.</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Azcuaga, Valery Francisco Godinez 1995-01-01 This study addresses the surface wave propagation phenomena on fluid-saturated porous solids. The analytical method for calculation of surface wave velocities (Feng and Johnson, JASA, 74, 906, 1983) is extended to the case of a porous solid saturated with a wetting fluid in contact with a non-wetting fluid, in order to study a material combination suitable for experimental investigation. The analytical method is further extended to the case of a non-wetting fluid/wetting fluid-saturated porous solid interface with an arbitrary finite surface stiffness. These extensions of the analytical method allows to theoretically study surface wave propagation phenomena during the saturation process. A modification to the 2-D space-time reflection Green's function (Feng and Johnson, JASA, 74, 915, 1983) is introduced in order to simulate the behavior of surface wave signals detected during the experimental investigation of surface wave propagation on fluid-saturated porous solids (Nagy, Appl. Phys. Lett., 60, 2735, 1992). This modification, together with the introduction of an excess attenuation for the Rayleigh surface mode, makes it possible to explain the apparent velocity changes observed on the surface wave signals during saturation. Experimental results concerning the propagation of surface waves on an alcohol-saturated porous glass are presented. These experiments were performed at frequencies of 500 and 800 kHz and show the simultaneous propagation of the two surface modes predicted by the extended analytical method. Finally an analysis of the displacements associated with the different surface modes is presented. This analysis reveals that it is possible to favor the generation of the Rayleigh surface mode or of the slow surface mode, simply by changing the type of transducer used in the generation of surface waves. Calculations show that a shear transducer couples more energy into the Rayleigh mode, whereas a longitudinal transducer couples more energy into the slow </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li class="active">21</li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> </div> <div id="page_22" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li class="active">22</li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="421"> <li> <a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3219142','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3219142">Influence of coastal vegetation on the 2004 tsunami wave impact in west Aceh</a> <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a> Laso Bayas, Juan Carlos; Marohn, Carsten; Dercon, Gerd; Dewi, Sonya; Piepho, Hans Peter; Joshi, Laxman; van Noordwijk, Meine; Cadisch, Georg 2011-01-01 In a tsunami event human casualties and infrastructure damage are determined predominantly by seaquake intensity and offshore properties. On land, wave energy is attenuated by gravitation (elevation) and friction (land cover). Tree belts have been promoted as “bioshields” against wave impact. However, given the lack of quantitative evidence of their performance in such extreme events, tree belts have been criticized for creating a false sense of security. This study used 180 transects perpendicular to over 100 km on the west coast of Aceh, Indonesia to analyze the influence of coastal vegetation, particularly cultivated trees, on the impact of the 2004 tsunami. Satellite imagery; land cover maps; land use characteristics; stem diameter, height, and planting density; and a literature review were used to develop a land cover roughness coefficient accounting for the resistance offered by different land uses to the wave advance. Applying a spatial generalized linear mixed model, we found that while distance to coast was the dominant determinant of impact (casualties and infrastructure damage), the existing coastal vegetation in front of settlements also significantly reduced casualties by an average of 5%. In contrast, dense vegetation behind villages endangered human lives and increased structural damage. Debris carried by the backwash may have contributed to these dissimilar effects of land cover. For sustainable and effective coastal risk management, location of settlements is essential, while the protective potential of coastal vegetation, as determined by its spatial arrangement, should be regarded as an important livelihood provider rather than just as a bioshield. PMID:22065751 </li> <li> <a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/21344675-wave-propagation-downstream-high-power-helicon-dipolelike-magnetic-field','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/21344675-wave-propagation-downstream-high-power-helicon-dipolelike-magnetic-field">Wave propagation downstream of a high power helicon in a dipolelike magnetic field</a> <a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a> Prager, James; Winglee, Robert; Roberson, B. Race 2010-01-15 The wave propagating downstream of a high power helicon source in a diverging magnetic field was investigated experimentally. The magnetic field of the wave has been measured both axially and radially. The three-dimensional structure of the propagating wave is observed and its wavelength and phase velocity are determined. The measurements are compared to predictions from helicon theory and that of a freely propagating whistler wave. The implications of this work on the helicon as a thruster are also discussed. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017PEPS....4...42I','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017PEPS....4...42I">Paleo-tsunami history along the northern Japan Trench: evidence from Noda Village, northern Sanriku coast, Japan</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Inoue, Taiga; Goto, Kazuhisa; Nishimura, Yuichi; Watanabe, Masashi; Iijima, Yasutaka; Sugawara, Daisuke 2017-12-01 Throughout history, large tsunamis have frequently affected the Sanriku area of the Pacific coast of the Tohoku region, Japan, which faces the Japan Trench. Although a few studies have examined paleo-tsunami deposits along the Sanriku coast, additional studies of paleo-earthquakes and tsunamis are needed to improve our knowledge of the timing, recurrence interval, and size of historical and pre-historic tsunamis. At Noda Village, in Iwate Prefecture on the northern Sanriku coast, we found at least four distinct gravelly sand layers based on correlation and chronological data. Sedimentary features such as grain size and thickness suggest that extreme waves from the sea formed these layers. Numerical modeling of storm waves further confirmed that even extremely large storm waves cannot account for the distribution of the gravelly sand layers, suggesting that these deposits are highly likely to have formed by tsunami waves. The numerical method of storm waves can be useful to identify sand layers as tsunami deposits if the deposits are observed far inland or at high elevations. The depositional age of the youngest tsunami deposit is consistent with the AD 869 Jogan earthquake tsunami, a possible predecessor of the AD 2011 Tohoku-oki tsunami. If this is the case, then the study site currently defines the possible northern extent of the AD 869 Jogan tsunami deposit, which is an important step in improving the tsunami source model of the AD 869 Jogan tsunami. Our results suggest that four large tsunamis struck the Noda site between 1100 and 2700 cal BP. The local tsunami sizes are comparable to the AD 2011 and AD 1896 Meiji Sanriku tsunamis, considering the landward extent of each tsunami deposit. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017A%26A...602A..75R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017A%26A...602A..75R">Observations of apparent superslow wave propagation in solar prominences</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Raes, J. O.; Van Doorsselaere, T.; Baes, M.; Wright, A. N. 2017-06-01 Context. Phase mixing of standing continuum Alfvén waves and/or continuum slow waves in atmospheric magnetic structures such as coronal arcades can create the apparent effect of a wave propagating across the magnetic field. Aims: We observe a prominence with SDO/AIA on 2015 March 15 and find the presence of oscillatory motion. We aim to demonstrate that interpreting this motion as a magneto hydrodynamic (MHD) wave is faulty. We also connect the decrease of the apparent velocity over time with the phase mixing process, which depends on the curvature of the magnetic field lines. Methods: By measuring the displacement of the prominence at different heights to calculate the apparent velocity, we show that the propagation slows down over time, in accordance with the theoretical work of Kaneko et al. We also show that this propagation speed drops below what is to be expected for even slow MHD waves for those circumstances. We use a modified Kippenhahn-Schlüter prominence model to calculate the curvature of the magnetic field and fit our observations accordingly. Results: Measuring three of the apparent waves, we get apparent velocities of 14, 8, and 4 km s-1. Fitting a simple model for the magnetic field configuration, we obtain that the filament is located 103 Mm below the magnetic centre. We also obtain that the scale of the magnetic field strength in the vertical direction plays no role in the concept of apparent superslow waves and that the moment of excitation of the waves happened roughly one oscillation period before the end of the eruption that excited the oscillation. Conclusions: Some of the observed phase velocities are lower than expected for slow modes for the circumstances, showing that they rather fit with the concept of apparent superslow propagation. A fit with our magnetic field model allows for inferring the magnetic geometry of the prominence. The movie attached to Fig. 1 is available at http://www.aanda.org </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2007APS..DPPGP8031A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2007APS..DPPGP8031A">Studies of nonlinear interactions between counter-propagating Alfv'en waves in the LAPD</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Auerbach, D. W.; Perez, J. C.; Carter, T. A.; Boldyrev, S. 2007-11-01 From a weak turbulence point of view, nonlinear interactions between shear Alfv'en waves are fundamental to the energy cascade in low-frequency magnetic turbulence. We report here on an experimental study of counter-propagating Alfv'en wave interactions in the Large Plasma Device (LAPD) at UCLA. Colliding, orthogonally polarized kinetic Alfv'en waves are generated by two antennae, separated by 5m along the guide magnetic field. Magnetic field and langmuir probes record plasma behavior between the antennae. When each antenna is operated separately, linearly polarized Alfv'en waves propagate in opposite directions along the guide field. When two antennae simultaneously excite counter propagating waves, we observe multiple side bands in the frequency domain, whose amplitude scales quadratically with wave amplitude. In the spatial domain we observe non-linear superposition in the 2D structure of the waves and spectral broadening in the perpendicular wave-number spectrum. This indicates the presence of nonlinear interaction of the counter propagating Alfv'en waves, and opens the possiblity to investigate Alfv'enic plasma turbulence in controlled and reproducible laboratory experiments. </li> <li> <a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70034454','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70034454">Nearshore Tsunami Inundation Model Validation: Toward Sediment Transport Applications</a> <a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a> Apotsos, Alex; Buckley, Mark; Gelfenbaum, Guy; Jaffe, Bruce; Vatvani, Deepak 2011-01-01 Model predictions from a numerical model, Delft3D, based on the nonlinear shallow water equations are compared with analytical results and laboratory observations from seven tsunami-like benchmark experiments, and with field observations from the 26 December 2004 Indian Ocean tsunami. The model accurately predicts the magnitude and timing of the measured water levels and flow velocities, as well as the magnitude of the maximum inundation distance and run-up, for both breaking and non-breaking waves. The shock-capturing numerical scheme employed describes well the total decrease in wave height due to breaking, but does not reproduce the observed shoaling near the break point. The maximum water levels observed onshore near Kuala Meurisi, Sumatra, following the 26 December 2004 tsunami are well predicted given the uncertainty in the model setup. The good agreement between the model predictions and the analytical results and observations demonstrates that the numerical solution and wetting and drying methods employed are appropriate for modeling tsunami inundation for breaking and non-breaking long waves. Extension of the model to include sediment transport may be appropriate for long, non-breaking tsunami waves. Using available sediment transport formulations, the sediment deposit thickness at Kuala Meurisi is predicted generally within a factor of 2. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017SSRv..211..571B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017SSRv..211..571B">Simulations of Seismic Wave Propagation on Mars</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Bozdağ, Ebru; Ruan, Youyi; Metthez, Nathan; Khan, Amir; Leng, Kuangdai; van Driel, Martin; Wieczorek, Mark; Rivoldini, Attilio; Larmat, Carène S.; Giardini, Domenico; Tromp, Jeroen; Lognonné, Philippe; Banerdt, Bruce W. 2017-10-01 We present global and regional synthetic seismograms computed for 1D and 3D Mars models based on the spectral-element method. For global simulations, we implemented a radially-symmetric Mars model with a 110 km thick crust (Sohl and Spohn in J. Geophys. Res., Planets 102(E1):1613-1635, 1997). For this 1D model, we successfully benchmarked the 3D seismic wave propagation solver SPECFEM3D_GLOBE (Komatitsch and Tromp in Geophys. J. Int. 149(2):390-412, 2002a; 150(1):303-318, 2002b) against the 2D axisymmetric wave propagation solver AxiSEM (Nissen-Meyer et al. in Solid Earth 5(1):425-445, 2014) at periods down to 10 s. We also present higher-resolution body-wave simulations with AxiSEM down to 1 s in a model with a more complex 1D crust, revealing wave propagation effects that would have been difficult to interpret based on ray theory. For 3D global simulations based on SPECFEM3D_GLOBE, we superimposed 3D crustal thickness variations capturing the distinct crustal dichotomy between Mars' northern and southern hemispheres, as well as topography, ellipticity, gravity, and rotation. The global simulations clearly indicate that the 3D crust speeds up body waves compared to the reference 1D model, whereas it significantly changes surface waveforms and their dispersive character depending on its thickness. We also perform regional simulations with the solver SES3D (Fichtner et al. Geophys. J. Int. 179:1703-1725, 2009) based on 3D crustal models derived from surface composition, thereby addressing the effects of various distinct crustal features down to 2 s. The regional simulations confirm the strong effects of crustal variations on waveforms. We conclude that the numerical tools are ready for examining more scenarios, including various other seismic models and sources. </li> <li> <a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26245839','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26245839">Destructive tsunami-like wave generated by surf beat over a coral reef during Typhoon Haiyan.</a> <a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a> Roeber, Volker; Bricker, Jeremy D 2015-08-06 Storm surges cause coastal inundation due to setup of the water surface resulting from atmospheric pressure, surface winds and breaking waves. Here we show that during Typhoon Haiyan, the setup generated by breaking waves near the fringing-reef-protected town of Hernani, the Philippines, oscillated with the incidence of large and small wave groups, and steepened into a tsunami-like wave that caused extensive damage and casualties. Though fringing reefs usually protect coastal communities from moderate storms, they can exacerbate flooding during strong events with energetic waves. Typical for reef-type bathymetries, a very short wave-breaking zone over the steep reef face facilitates the freeing of infragravity-period fluctuations (surf beat) with little energy loss. Since coastal flood planning relies on phase-averaged wave modelling, infragravity surges are not being accounted for. This highlights the necessity for a policy change and the adoption of phase-resolving wave models for hazard assessment in regions with fringing reefs. </li> <li> <a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4918328','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4918328">Destructive tsunami-like wave generated by surf beat over a coral reef during Typhoon Haiyan</a> <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a> Roeber, Volker; Bricker, Jeremy D. 2015-01-01 Storm surges cause coastal inundation due to setup of the water surface resulting from atmospheric pressure, surface winds and breaking waves. Here we show that during Typhoon Haiyan, the setup generated by breaking waves near the fringing-reef-protected town of Hernani, the Philippines, oscillated with the incidence of large and small wave groups, and steepened into a tsunami-like wave that caused extensive damage and casualties. Though fringing reefs usually protect coastal communities from moderate storms, they can exacerbate flooding during strong events with energetic waves. Typical for reef-type bathymetries, a very short wave-breaking zone over the steep reef face facilitates the freeing of infragravity-period fluctuations (surf beat) with little energy loss. Since coastal flood planning relies on phase-averaged wave modelling, infragravity surges are not being accounted for. This highlights the necessity for a policy change and the adoption of phase-resolving wave models for hazard assessment in regions with fringing reefs. PMID:26245839 </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018PhPl...25a3707D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018PhPl...25a3707D">Propagation characteristics of electromagnetic waves in dusty plasma with full ionization</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Dan, Li; Guo, Li-Xin; Li, Jiang-Ting 2018-01-01 This study investigates the propagation characteristics of electromagnetic (EM) waves in fully ionized dusty plasmas. The propagation characteristics of fully ionized plasma with and without dust under the Fokker-Planck-Landau (FPL) and Bhatnagar-Gross-Krook (BGK) models are compared to those of weakly ionized plasmas by using the propagation matrix method. It is shown that the FPL model is suitable for the analysis of the propagation characteristics of weakly collisional and fully ionized dusty plasmas, as is the BGK model. The influence of varying the dust parameters on the propagation properties of EM waves in the fully ionized dusty plasma was analyzed using the FPL model. The simulation results indicated that the densities and average radii of dust grains influence the reflection and transmission coefficients of fully ionized dusty plasma slabs. These results may be utilized to analyze the effects of interaction between EM waves and dusty plasmas, such as those associated with hypersonic vehicles. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016JMSA...15..307L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016JMSA...15..307L">Development of jacket platform tsunami risk rating system in waters offshore North Borneo</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Lee, H. E.; Liew, M. S.; Mardi, N. H.; Na, K. L.; Toloue, Iraj; Wong, S. K. 2016-09-01 This work details the simulation of tsunami waves generated by seaquakes in the Manila Trench and their effect on fixed oil and gas jacket platforms in waters offshore North Borneo. For this study, a four-leg living quarter jacket platform located in a water depth of 63m is modelled in SACS v5.3. Malaysia has traditionally been perceived to be safe from the hazards of earthquakes and tsunamis. Local design practices tend to neglect tsunami waves and include no such provisions. In 2004, a 9.3 M w seaquake occurred off the northwest coast of Aceh, which generated tsunami waves that caused destruction in Malaysia totalling US 25 million and 68 deaths. This event prompted an awareness of the need to study the reliability of fixed offshore platforms scattered throughout Malaysian waters. In this paper, we present a review of research on the seismicity of the Manila Trench, which is perceived to be high risk for Southeast Asia. From the tsunami numerical model TUNA-M2, we extract computer-simulated tsunami waves at prescribed grid points in the vicinity of the platforms in the region. Using wave heights as input, we simulate the tsunami using SACS v5.3 structural analysis software of offshore platforms, which is widely accepted by the industry. We employ the nonlinear solitary wave theory in our tsunami loading calculations for the platforms, and formulate a platform-specific risk quantification system. We then perform an intensive structural sensitivity analysis and derive a corresponding platform-specific risk rating model. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010ASSP...19..433G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010ASSP...19..433G">Statistical Detection of Propagating Waves in a Polar Coronal Hole</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Gupta, G. R.; O'Shea, E.; Banerjee, D.; Popescu, M.; Doyle, J. G. Waves are important in the heating of the solar corona and the acceleration of the solar wind. We have examined a long spectral time series sampling a southern coronal hole, observed on the 25 February 1997 using the SUMER spectrometer onboard SoHO. The observations used the spectra lines NIV 765Å, formed in the transition region, and Ne VIII 770Å, formed in the low corona. The spectra indicate the presence of compressional waves with periods of about 18 min, and also significant power at shorter periods. Using Fourier techniques, we measured the phase delays between the intensity as well as the velocity oscillations in the two lines as a function of frequency. From these measurements we derive the travel time of the propagating oscillations and so the propagation speeds of the waves producing the oscillations. As the measured propagation speeds are subsonic, we conclude that the observed waves are slow magneto-acoustic ones. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AIPC.1650.1178K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AIPC.1650.1178K">Numerical simulation and experimental validation of Lamb wave propagation behavior in composite plates</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Kim, Sungwon; Uprety, Bibhisha; Mathews, V. John; Adams, Daniel O. 2015-03-01 Structural Health Monitoring (SHM) based on Acoustic Emission (AE) is dependent on both the sensors to detect an impact event as well as an algorithm to determine the impact location. The propagation of Lamb waves produced by an impact event in thin composite structures is affected by several unique aspects including material anisotropy, ply orientations, and geometric discontinuities within the structure. The development of accurate numerical models of Lamb wave propagation has important benefits towards the development of AE-based SHM systems for impact location estimation. Currently, many impact location algorithms utilize the time of arrival or velocities of Lamb waves. Therefore the numerical prediction of characteristic wave velocities is of great interest. Additionally, the propagation of the initial symmetric (S0) and asymmetric (A0) wave modes is important, as these wave modes are used for time of arrival estimation. In this investigation, finite element analyses were performed to investigate aspects of Lamb wave propagation in composite plates with active signal excitation. A comparative evaluation of two three-dimensional modeling approaches was performed, with emphasis placed on the propagation and velocity of both the S0 and A0 wave modes. Results from numerical simulations are compared to experimental results obtained from active AE testing. Of particular interest is the directional dependence of Lamb waves in quasi-isotropic carbon/epoxy composite plates. Numerical and experimental results suggest that although a quasi-isotropic composite plate may have the same effective elastic modulus in all in-plane directions, the Lamb wave velocity may have some directional dependence. Further numerical analyses were performed to investigate Lamb wave propagation associated with circular cutouts in composite plates. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017JASTP.159....7J','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017JASTP.159....7J">Ionospheric effects of magneto-acoustic-gravity waves: Dispersion relation</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Jones, R. Michael; Ostrovsky, Lev A.; Bedard, Alfred J. 2017-06-01 There is extensive evidence for ionospheric effects associated with earthquake-related atmospheric disturbances. Although the existence of earthquake precursors is controversial, one suggested method of detecting possible earthquake precursors and tsunamis is by observing possible ionospheric effects of atmospheric waves generated by such events. To study magneto-acoustic-gravity waves in the atmosphere, we have derived a general dispersion relation including the effects of the Earth's magnetic field. This dispersion relation can be used in a general atmospheric ray tracing program to calculate the propagation of magneto-acoustic-gravity waves from the ground to the ionosphere. The presence of the Earth's magnetic field in the ionosphere can radically change the dispersion properties of the wave. The general dispersion relation obtained here reduces to the known dispersion relations for magnetoacoustic waves and acoustic-gravity waves in the corresponding particular cases. The work described here is the first step in achieving a generalized ray tracing program permitting propagation studies of magneto-acoustic-gravity waves. </li> <li> <a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70190383','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70190383">Tsunami simulations of the 1867 Virgin Island earthquake: Constraints on epicenter location and fault parameters</a> <a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a> Barkan, Roy; ten Brink, Uri S. 2010-01-01 The 18 November 1867 Virgin Island earthquake and the tsunami that closely followed caused considerable loss of life and damage in several places in the northeast Caribbean region. The earthquake was likely a manifestation of the complex tectonic deformation of the Anegada Passage, which cuts across the Antilles island arc between the Virgin Islands and the Lesser Antilles. In this article, we attempt to characterize the 1867 earthquake with respect to fault orientation, rake, dip, fault dimensions, and first tsunami wave propagating phase, using tsunami simulations that employ high-resolution multibeam bathymetry. In addition, we present new geophysical and geological observations from the region of the suggested earthquake source. Results of our tsunami simulations based on relative amplitude comparison limit the earthquake source to be along the northern wall of the Virgin Islands basin, as suggested by Reid and Taber (1920), or on the carbonate platform north of the basin, and not in the Virgin Islands basin, as commonly assumed. The numerical simulations suggest the 1867 fault was striking 120°–135° and had a mixed normal and left-lateral motion. First propagating wave phase analysis suggests a fault striking 300°–315° is also possible. The best-fitting rupture length was found to be relatively small (50 km), probably indicating the earthquake had a moment magnitude of ∼7.2. Detailed multibeam echo sounder surveys of the Anegada Passage bathymetry between St. Croix and St. Thomas reveal a scarp, which cuts the northern wall of the Virgin Islands basin. High-resolution seismic profiles further indicate it to be a reasonable fault candidate. However, the fault orientation and the orientation of other subparallel faults in the area are more compatible with right-lateral motion. For the other possible source region, no clear disruption in the bathymetry or seismic profiles was found on the carbonate platform north of the basin. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010AGUFM.T23C2280G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010AGUFM.T23C2280G">Forecasting database for the tsunami warning regional center for the western Mediterranean Sea</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Gailler, A.; Hebert, H.; Loevenbruck, A.; Hernandez, B. 2010-12-01 Improvements in the availability of sea-level observations and advances in numerical modeling techniques are increasing the potential for tsunami warnings to be based on numerical model forecasts. Numerical tsunami propagation and inundation models are well developed, but they present a challenge to run in real-time, partly due to computational limitations and also to a lack of detailed knowledge on the earthquake rupture parameters. Through the establishment of the tsunami warning regional center for NE Atlantic and western Mediterranean Sea, the CEA is especially in charge of providing rapidly a map with uncertainties showing zones in the main axis of energy at the Mediterranean scale. The strategy is based initially on a pre-computed tsunami scenarios database, as source parameters available a short time after an earthquake occurs are preliminary and may be somewhat inaccurate. Existing numerical models are good enough to provide a useful guidance for warning structures to be quickly disseminated. When an event will occur, an appropriate variety of offshore tsunami propagation scenarios by combining pre-computed propagation solutions (single or multi sources) may be recalled through an automatic interface. This approach would provide quick estimates of tsunami offshore propagation, and aid hazard assessment and evacuation decision-making. As numerical model accuracy is inherently limited by errors in bathymetry and topography, and as inundation maps calculation is more complex and expensive in term of computational time, only tsunami offshore propagation modeling will be included in the forecasting database using a single sparse bathymetric computation grid for the numerical modeling. Because of too much variability in the mechanism of tsunamigenic earthquakes, all possible magnitudes cannot be represented in the scenarios database. In principle, an infinite number of tsunami propagation scenarios can be constructed by linear combinations of a finite number of </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2002EGSGA..27.1427S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2002EGSGA..27.1427S">Numerical Simulations of Upstream Propagating Solitary Waves and Wave Breaking In A Stratified Fjord</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Stastna, M.; Peltier, W. R. In this talk we will discuss ongoing numerical modeling of the flow of a stratified fluid over large scale topography motivated by observations in Knight Inlet, a fjord in British Columbia, Canada. After briefly surveying the work done on the topic in the past we will discuss our latest set of simulations in which we have observed the gener- ation and breaking of three different types of nonlinear internal waves in the lee of the sill topography. The first type of wave observed is a large lee wave in the weakly strat- ified main portion of the water column, The second is an upward propagating internal wave forced by topography that breaks in the strong, near-surface pycnocline. The third is a train of upstream propagating solitary waves that, in certain circumstances, form as breaking waves consisting of a nearly solitary wave envelope and a highly unsteady core near the surface. Time premitting, we will comment on the implications of these results for our long term goal of quantifying tidally driven mixing in Knight Inlet. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018JOpt...20d5603F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018JOpt...20d5603F">Wave propagation in metamaterials mimicking the topology of a cosmic string</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Fernández-Núñez, Isabel; Bulashenko, Oleg 2018-04-01 We study the interference and diffraction of light when it propagates through a metamaterial medium mimicking the spacetime of a cosmic string—a topological defect with curvature singularity. The phenomenon may look like a gravitational analogue of the Aharonov-Bohm effect, since the light propagates in a region where the Riemann tensor vanishes, being nonetheless affected by the non-zero curvature confined to the string core. We carry out the full-wave numerical simulation of the metamaterial medium and give the analytical interpretation of the results by use of the asymptotic theory of diffraction, which turns out to be in excellent agreement. In particular, we show that the main features of wave propagation in a medium with conical singularity can be explained by four-wave interference involving two geometrical optics and two diffracted waves. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012APS..MARW15010H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012APS..MARW15010H">Manipulation of propagating spin waves in straight and curved magnetic microstrips</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Haldar, Arabinda; Liu, Hau-Jian; Schultheiss, Helmut; Vogt, Katrin; Hoffmann, Axel; Buchanan, Kristen 2012-02-01 The main challenges in realizing magnonics devices are the generation, manipulation and detection of spin waves, especially in metallic magnetic materials where the length scales are of interest for applications. We have studied the propagation of spin waves in transversely magnetized Permalloy (Py) microstrips of different shapes using micro-Brillouin light scattering. The Py stripe was 30-nm thick, several micrometers wide and >50 μm long. Spin waves were excited in the Py strip using a 2-μm wide antenna. We compare the spin wave propagation along a straight wire to the propagation along a magnetic microstrip with a smooth bend. We will also discuss the use of a current through a gold wire under the Permalloy to provide a local magnetic field to maintain a transverse magnetization around the bend. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2006APhy...52..623A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2006APhy...52..623A">Parabolic equation for nonlinear acoustic wave propagation in inhomogeneous moving media</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Aver'yanov, M. V.; Khokhlova, V. A.; Sapozhnikov, O. A.; Blanc-Benon, Ph.; Cleveland, R. O. 2006-12-01 A new parabolic equation is derived to describe the propagation of nonlinear sound waves in inhomogeneous moving media. The equation accounts for diffraction, nonlinearity, absorption, scalar inhomogeneities (density and sound speed), and vectorial inhomogeneities (flow). A numerical algorithm employed earlier to solve the KZK equation is adapted to this more general case. A two-dimensional version of the algorithm is used to investigate the propagation of nonlinear periodic waves in media with random inhomogeneities. For the case of scalar inhomogeneities, including the case of a flow parallel to the wave propagation direction, a complex acoustic field structure with multiple caustics is obtained. Inclusion of the transverse component of vectorial random inhomogeneities has little effect on the acoustic field. However, when a uniform transverse flow is present, the field structure is shifted without changing its morphology. The impact of nonlinearity is twofold: it produces strong shock waves in focal regions, while, outside the caustics, it produces higher harmonics without any shocks. When the intensity is averaged across the beam propagating through a random medium, it evolves similarly to the intensity of a plane nonlinear wave, indicating that the transverse redistribution of acoustic energy gives no considerable contribution to nonlinear absorption. </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li class="active">22</li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> </div> <div id="page_23" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li class="active">23</li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>25</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="441"> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017SMaS...26b5020R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017SMaS...26b5020R">Visualization of stress wave propagation via air-coupled acoustic emission sensors</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Rivey, Joshua C.; Lee, Gil-Yong; Yang, Jinkyu; Kim, Youngkey; Kim, Sungchan 2017-02-01 We experimentally demonstrate the feasibility of visualizing stress waves propagating in plates using air-coupled acoustic emission sensors. Specifically, we employ a device that embeds arrays of microphones around an optical lens in a helical pattern. By implementing a beamforming technique, this remote sensing system allows us to record wave propagation events in situ via a single-shot and full-field measurement. This is a significant improvement over the conventional wave propagation tracking approaches based on laser doppler vibrometry or digital image correlation techniques. In this paper, we focus on demonstrating the feasibility and efficacy of this air-coupled acoustic emission technique by using large metallic plates exposed to external impacts. The visualization results of stress wave propagation will be shown under various impact scenarios. The proposed technique can be used to characterize and localize damage by detecting the attenuation, reflection, and scattering of stress waves that occurs at damage locations. This can ultimately lead to the development of new structural health monitoring and nondestructive evaluation methods for identifying hidden cracks or delaminations in metallic or composite plate structures, simultaneously negating the need for mounted contact sensors. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFMNH51B0119Y','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFMNH51B0119Y">Atmospheric gravity wave detection following the 2011 Tohoku earthquakes combining COSMIC occultation and GPS observations</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Yan, X.; Tao, Y.; Xia, C.; Qi, Y.; Zuo, X. 2017-12-01 Several studies have reported the earthquake-induced atmospheric gravity waves detected by some new technologies such as airglow (Makela et al., 2011), GOCE (Garcia et al., 2013), GRACE (Yang et al., 2014), F3/C radio occultation sounding (Coïsson et al., 2015). In this work, we collected all occultation events on 11 March, and selected four events to analyze at last. The original and filtered podTEC is represented as function of the altitude of the impact parameter and UT of the four events. Then, the travel time diagrams of filtered podTEC derived from the events were analyzed. The occultation signal from one event (marked as No.73) is consistent with the previous results reported by Coïsson. 2015, which is corresponds to the ionospheric signal induced from tsunami gravity wave. What is noticeable, in this work, is that three occultation events of No.403, 77 and 118 revealed a disturbance of atmospheric gravity wave with velocity 300m/s, preceding the tsunami. It would probably be correspond to the gravity waves caused by seismic rupture but not tsunami. In addition, it can be seen that the perturbation height of occultation observation TEC is concentrated at 200-400km, corresponding ionosphere F region. The signals detected above are compared with GPS measurements of TEC from GEONET and IGS. From GPS data, traveling ionospheric disturbances were observed spreading out from the epicenter as a quasi-circular propagation pattern with the time. Exactly, we observed an acoustic wave coupled with Rayleigh wave starting from the epicenter with a speed of 3.0km/s and a superimposed acoustic-gravity wave moving with a speed of 800m/s. The acoustic-gravity wave generated at the epicenter and gradually attenuated 800km away, then it is replaced by a gravity wave coupled with the tsunami that moves with a speed of between 100 and 300m/s. It is necessary to confirm the propagation process of the waves if we attempt to evaluate the use of ionospheric seismology as a </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018GeoRL..45.2064D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018GeoRL..45.2064D">Rossby Wave Propagation into the Northern Hemisphere Stratosphere: The Role of Zonal Phase Speed</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Domeisen, Daniela I. V.; Martius, Olivia; Jiménez-Esteve, Bernat 2018-02-01 Sudden stratospheric warming (SSW) events are to a dominant part induced by upward propagating planetary waves. While theory predicts that the zonal phase speed of a tropospheric wave forcing affects wave propagation into the stratosphere, its relevance for SSW events has so far not been considered. This study shows in a linear wave diagnostic and in reanalysis data that phase speeds tend eastward as waves propagate upward, indicating that the stratosphere preselects eastward phase speeds for propagation, especially for zonal wave number 2. This also affects SSW events: Split SSW events tend to be preceded by anomalously eastward zonal phase speeds. Zonal phase speed may indeed explain part of the increased wave flux observed during the preconditioning of SSW events, as, for example, for the record 2009 SSW event. </li> <li> <a target="_blank" onclick="trackOutboundLink('https://rosap.ntl.bts.gov/view/dot/14682','DOTNTL'); return false;" href="https://rosap.ntl.bts.gov/view/dot/14682">An introduction to wave propagation in pavements and soils : theory and practice</a> <a target="_blank" href="http://ntlsearch.bts.gov/tris/index.do">DOT National Transportation Integrated Search</a> 1999-02-01 This paper introduces the physics and analyst of wave propagation in pavement and soils. The study of wave propagation in soils can yield useful results to engineers concerned with resilient characteristics of a particular site, dynamic soils structu... </li> <li> <a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26482393','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26482393">Propagation of ultrasonic Love waves in nonhomogeneous elastic functionally graded materials.</a> <a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a> Kiełczyński, P; Szalewski, M; Balcerzak, A; Wieja, K 2016-02-01 This paper presents a theoretical study of the propagation behavior of ultrasonic Love waves in nonhomogeneous functionally graded elastic materials, which is a vital problem in the mechanics of solids. The elastic properties (shear modulus) of a semi-infinite elastic half-space vary monotonically with the depth (distance from the surface of the material). The Direct Sturm-Liouville Problem that describes the propagation of Love waves in nonhomogeneous elastic functionally graded materials is formulated and solved by using two methods: i.e., (1) Finite Difference Method, and (2) Haskell-Thompson Transfer Matrix Method. The dispersion curves of phase and group velocity of surface Love waves in inhomogeneous elastic graded materials are evaluated. The integral formula for the group velocity of Love waves in nonhomogeneous elastic graded materials has been established. The effect of elastic non-homogeneities on the dispersion curves of Love waves is discussed. Two Love wave waveguide structures are analyzed: (1) a nonhomogeneous elastic surface layer deposited on a homogeneous elastic substrate, and (2) a semi-infinite nonhomogeneous elastic half-space. Obtained in this work, the phase and group velocity dispersion curves of Love waves propagating in the considered nonhomogeneous elastic waveguides have not previously been reported in the scientific literature. The results of this paper may give a deeper insight into the nature of Love waves propagation in elastic nonhomogeneous functionally graded materials, and can provide theoretical guidance for the design and optimization of Love wave based devices. Copyright © 2015 Elsevier B.V. All rights reserved. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1999JMP....40..511P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1999JMP....40..511P">Propagation estimates for dispersive wave equations: Application to the stratified wave equation</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Pravica, David W. 1999-01-01 The plane-stratified wave equation (∂t2+H)ψ=0 with H=-c(y)2∇z2 is studied, where z=x⊕y, x∈Rk, y∈R1 and |c(y)-c∞|→0 as |y|→∞. Solutions to such an equation are solved for the propagation of waves through a layered medium and can include waves which propagate in the x-directions only (i.e., trapped modes). This leads to a consideration of the pseudo-differential wave equation (∂t2+ω(-Δx))ψ=0 such that the dispersion relation ω(ξ2) is analytic and satisfies c1⩽ω'(ξ2)⩽c2 for c*>0. Uniform propagation estimates like ∫|x|⩽|t|αE(UtP±φ0)dkx⩽Cα,β(1+|t|)-β∫E(φ0)dkx are obtained where Ut is the evolution group, P± are projection operators onto the Hilbert space of initial conditions φ∈H and E(ṡ) is the local energy density. In special cases scattering of trapped modes off a local perturbation satisfies the causality estimate ||P+ρΛjSP-ρΛk||⩽Cνρ-ν for each ν<1/2. Here P+ρΛj (P-ρΛk) are remote outgoing/detector (incoming/transmitter) projections for the jth (kth) trapped mode. Also Λ⋐R+ is compact, so the projections localize onto formally-incoming (eventually-outgoing) states. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFMNH23A0208T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFMNH23A0208T">Real-time correction of tsunami site effect by frequency-dependent tsunami-amplification factor</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Tsushima, H. 2017-12-01 For tsunami early warning, I developed frequency-dependent tsunami-amplification factor and used it to design a recursive digital filter that can be applicable for real-time correction of tsunami site response. In this study, I assumed that a tsunami waveform at an observing point could be modeled by convolution of source, path and site effects in time domain. Under this assumption, spectral ratio between offshore and the nearby coast can be regarded as site response (i.e. frequency-dependent amplification factor). If the amplification factor can be prepared before tsunamigenic earthquakes, its temporal convolution to offshore tsunami waveform provides tsunami prediction at coast in real time. In this study, tsunami waveforms calculated by tsunami numerical simulations were used to develop frequency-dependent tsunami-amplification factor. Firstly, I performed numerical tsunami simulations based on nonlinear shallow-water theory from many tsuanmigenic earthquake scenarios by varying the seismic magnitudes and locations. The resultant tsunami waveforms at offshore and the nearby coastal observing points were then used in spectral-ratio analysis. An average of the resulted spectral ratios from the tsunamigenic-earthquake scenarios is regarded as frequency-dependent amplification factor. Finally, the estimated amplification factor is used in design of a recursive digital filter that can be applicable in time domain. The above procedure is applied to Miyako bay at the Pacific coast of northeastern Japan. The averaged tsunami-height spectral ratio (i.e. amplification factor) between the location at the center of the bay and the outside show a peak at wave-period of 20 min. A recursive digital filter based on the estimated amplification factor shows good performance in real-time correction of tsunami-height amplification due to the site effect. This study is supported by Japan Society for the Promotion of Science (JSPS) KAKENHI grant 15K16309. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2008AGUFM.U33C..04G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2008AGUFM.U33C..04G">Issues and Advances in Understanding Landslide-Generated Tsunamis: Toward a Unified Model</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Geist, E. L.; Locat, J.; Lee, H. J.; Lynett, P. J.; Parsons, T.; Kayen, R. E.; Hart, P. E. 2008-12-01 matrix affects the overall rheologic behavior during slide dynamics. For more rigid materials, such as carbonate and volcanic rocks, models are being developed that encompass the initial fracturing and eventual disintegration associated with debris avalanches. Lastly, the physics dictating the hydrodynamics of landslide-generated tsunamis is equally complex. The effects of non-linearity and dispersion are not necessarily negligible for landslides (in contrast to most earthquake-generated tsunamis), indicating that numerical implementation of the non-linear Boussinesq equations is often needed. Moreover, we show that for near-field landslide tsunamis propagating across the continental shelf, bottom friction (bottom boundary layer turbulence) and wave breaking can be important energy sinks. Detailed geophysical surveys can dissect landslide complexes to determine the geometry of individual events and help estimate rheological properties of the flowing mass, whereas cores in landslide provinces can determine the mechanical properties and pore-pressure distribution for pre- and post-failure sediment. This information is critical toward developing well-documented case histories for validating physics-based landslide tsunami models. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012AIPC.1430.1299B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012AIPC.1430.1299B">Lamb wave propagation in a restricted geometry composite pi-joint specimen</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Blackshire, James L.; Soni, Som 2012-05-01 The propagation of elastic waves in a material can involve a number of complex physical phenomena, resulting in both subtle and dramatic effects on detected signal content. In recent years, the use of advanced methods for characterizing and imaging elastic wave propagation and scattering processes has increased, where for example the use of scanning laser vibrometry and advanced computational models have been used very effectively to identify propagating modes, scattering phenomena, and damage feature interactions. In the present effort, the propagation of Lamb waves within a narrow, constrained geometry composite pi-joint structure are studied using 3D finite element models and scanning laser vibrometry measurements, where the effects of varying sample thickness, complex joint curvatures, and restricted structure geometries are highlighted, and a direct comparison of computational and experimental results are provided for simulated and realistic geometry composite pi-joint samples. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://www.dtic.mil/docs/citations/ADA103878','DTIC-ST'); return false;" href="http://www.dtic.mil/docs/citations/ADA103878">Acceleration Wave Propagation in Hyperelastic Rods of Variable Cross-Section.</a> <a target="_blank" href="http://www.dtic.mil/">DTIC Science & Technology</a> 1981-07-01 direction of propagation. Many authors have considered both static and dynamic problems for such materials, of whom we mention only Antman [2] and... Antman and Jordan [3] who studied the Kirchhoff problem for nonlinearly elastic rods and qualitative properties in general, Jeffrey and Teymur [4] and...Jeffrey and Suhubi [5] who considered shock wave formation and acceleration wave propagation through periodically layered media, and Antman and Liu [6 </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017JGRD..12211301X','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017JGRD..12211301X">Impacts of Horizontal Propagation of Orographic Gravity Waves on the Wave Drag in the Stratosphere and Lower Mesosphere</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Xu, Xin; Wang, Yuan; Xue, Ming; Zhu, Kefeng 2017-11-01 The impact of horizontal propagation of mountain waves on the orographic gravity wave drag (OGWD) in the stratosphere and lower mesosphere of the Northern Hemisphere is evaluated for the first time. Using a fine-resolution (1 arc min) terrain and 2.5°×2.5° European Centre for Medium-Range Weather Forecasts ERA-Interim reanalysis data during 2011-2016, two sets of OGWD are calculated offline according to a traditional parameterization scheme (without horizontal propagation) and a newly proposed scheme (with horizontal propagation). In both cases, the zonal mean OGWDs show similar spatial patterns and undergo a notable seasonal variation. In winter, the OGWD is mainly distributed in the upper stratosphere and lower mesosphere of middle to high latitudes, whereas the summertime OGWD is confined in the lower stratosphere. Comparison between the two sets of OGWD reveal that the horizontal propagation of mountain waves tends to decrease (increase) the OGWD in the lower stratosphere (middle to upper stratosphere and lower mesosphere). Consequently, including the horizontal propagation of mountain waves in the parameterization of OGWD can reduce the excessive OGWD in the lower stratosphere and strengthen the insufficient gravity wave forcing in the mesosphere, which are the known problems of traditional OGWD schemes. The impact of horizontal propagation is more prominent in winter than in summer, with the OGWD in western Tibetan Plateau, Rocky Mountains, and Greenland notably affected. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2008GMS...182..147T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2008GMS...182..147T">The double landslide-induced tsunami</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Tinti, S.; Armigliat, A.; Manucci, A.; Pagnoni, G.; Tonini, R.; Zaniboni, F.; Maramai, A.; Graziani, L. The 2002 crisis of Stromboli culminated on December 30 in a series of mass failures detached from the Sciara del Fuoco, with two main landslides, one submarine followed about 7 min later by a second subaerial. These landslides caused two distinct tsunamis that were seen by most people in the island as a unique event. The double tsunami was strongly damaging, destroying several houses in the waterfront at Ficogrande, Punta Lena, and Scari localities in the northeastern coast of Stromboli. The waves affected also Panarea and were observed in the northern Sicily coast and even in Campania, but with minor effects. There are no direct instrumental records of these tsunamis. What we know resides on (1) observations and quantification of the impact of the waves on the coast, collected in a number of postevent field surveys; (2) interviews of eyewitnesses and a collection of tsunami images (photos and videos) taken by observers; and (3) on results of numerical simulations. In this paper, we propose a critical reconstruction of the events where all the available pieces of information are recomposed to form a coherent and consistent mosaic. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2006EP%26S...58..233P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2006EP%26S...58..233P">The large tsunami of 26 December 2004: Field observations and eyewitnesses accounts from Sri Lanka, Maldives Is. and Thailand</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Papadopoulos, Gerassimos A.; Caputo, Riccardo; McAdoo, Brian; Pavlides, Spyros; Karastathis, Vassilios; Fokaefs, Anna; Orfanogiannaki, Katerina; Valkaniotis, Sotiris 2006-02-01 Blue Lagoon Port of Phuket island as well as in Maya Bay, Phi-Phi islands, Thailand, were interviewed on the basis of a standard questionnaire. The first sea motion was a retreat of at least 100 m. Then, two main waves arrived, the first being the strong one occurring at about 09:55-10:05 local time, with h ˜ 6m in Padong causing significant destruction and human victims. The collected information clearly indicates that the tsunami propagated as the leading crest wave to the west side, e.g. in Sri Lanka and Maldives, and as the leading trough wave to the east, e.g. in Thailand. </li> <li> <a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4015334','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4015334">The stimulus-evoked population response in visual cortex of awake monkey is a propagating wave</a> <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a> Muller, Lyle; Reynaud, Alexandre; Chavane, Frédéric; Destexhe, Alain 2014-01-01 Propagating waves occur in many excitable media and were recently found in neural systems from retina to neocortex. While propagating waves are clearly present under anaesthesia, whether they also appear during awake and conscious states remains unclear. One possibility is that these waves are systematically missed in trial-averaged data, due to variability. Here we present a method for detecting propagating waves in noisy multichannel recordings. Applying this method to single-trial voltage-sensitive dye imaging data, we show that the stimulus-evoked population response in primary visual cortex of the awake monkey propagates as a travelling wave, with consistent dynamics across trials. A network model suggests that this reliability is the hallmark of the horizontal fibre network of superficial cortical layers. Propagating waves with similar properties occur independently in secondary visual cortex, but maintain precise phase relations with the waves in primary visual cortex. These results show that, in response to a visual stimulus, propagating waves are systematically evoked in several visual areas, generating a consistent spatiotemporal frame for further neuronal interactions. PMID:24770473 </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013AGUFMNH41B1722C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013AGUFMNH41B1722C">Transient Tsunamis in Lakes</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Couston, L.; Mei, C.; Alam, M. 2013-12-01 A large number of lakes are surrounded by steep and unstable mountains with slopes prone to failure. As a result, landslides are likely to occur and impact water sitting in closed reservoirs. These rare geological phenomena pose serious threats to dam reservoirs and nearshore facilities because they can generate unexpectedly large tsunami waves. In fact, the tallest wave experienced by contemporary humans occurred because of a landslide in the narrow bay of Lituya in 1958, and five years later, a deadly landslide tsunami overtopped Lake Vajont's dam, flooding and damaging villages along the lakefront and in the Piave valley. If unstable slopes and potential slides are detected ahead of time, inundation maps can be drawn to help people know the risks, and mitigate the destructive power of the ensuing waves. These maps give the maximum wave runup height along the lake's vertical and sloping boundaries, and can be obtained by numerical simulations. Keeping track of the moving shorelines along beaches is challenging in classical Eulerian formulations because the horizontal extent of the fluid domain can change over time. As a result, assuming a solid slide and nonbreaking waves, here we develop a nonlinear shallow-water model equation in the Lagrangian framework to address the problem of transient landslide-tsunamis. In this manner, the shorelines' three-dimensional motion is part of the solution. The model equation is hyperbolic and can be solved numerically by finite differences. Here, a 4th order Runge-Kutta method and a compact finite-difference scheme are implemented to integrate in time and spatially discretize the forced shallow-water equation in Lagrangian coordinates. The formulation is applied to different lake and slide geometries to better understand the effects of the lake's finite lengths and slide's forcing mechanism on the generated wavefield. Specifically, for a slide moving down a plane beach, we show that edge-waves trapped by the shoreline and free-waves </li> <li> <a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27657478','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27657478">Fourier Transform Ultrasound Spectroscopy for the determination of wave propagation parameters.</a> <a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a> Pal, Barnana 2017-01-01 The reported results for ultrasonic wave attenuation constant (α) in pure water show noticeable inconsistency in magnitude. A "Propagating-Wave" model analysis of the most popular pulse-echo technique indicates that this is a consequence of the inherent wave propagation characteristics in a bounded medium. In the present work Fourier Transform Ultrasound Spectroscopy (FTUS) is adopted to determine ultrasonic wave propagation parameters, the wave number (k) and attenuation constant (α) at 1MHz frequency in tri-distilled water at room temperature (25°C). Pulse-echo signals obtained under same experimental conditions regarding the exciting input signal and reflecting boundary wall of the water container for various lengths of water columns are captured. The Fast Fourier Transform (FFT) components of the echo signals are taken to compute k, α and r, the reflection constant at the boundary, using Oak Ridge and Oxford method. The results are compared with existing literature values. Copyright © 2016 Elsevier B.V. All rights reserved. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19730021203','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19730021203">A critical survey of wave propagation and impact in composite materials</a> <a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a> Moon, F. C. 1973-01-01 A review of the field of stress waves in composite materials is presented covering the period up to December 1972. The major properties of waves in composites are discussed and a summary is made of the major experimental results in this field. Various theoretical models for analysis of wave propagation in laminated, fiber and particle reinforced composites are surveyed. The anisotropic, dispersive and dissipative properties of stress pulses and shock waves in such materials are reviewed. A review of the behavior of composites under impact loading is presented along with the application of wave propagation concepts to the determination of impact stresses in composite plates. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2006AGUFMOS43C0683W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2006AGUFMOS43C0683W">Sediments from the Boxing Day tsunami on the coasts of southeastern India and Kenya</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Weiss, R.; Bahlburg, H. 2006-12-01 On the Boxing Day 2004, the world community experienced a catastrophic tsunami in the Indian Ocean and could also saw how unprepared and unaware countries along the Indian ocean were. Beyond the tragedy of the tremendous loss of lives, the result of this event is an opportunity to study a global tsunami (mega-tsunami) in many regards. Here, we report on tsunami sediments left behind on beaches at the coast of Tamil Nadu (India) and on beaches between Malindi and Lamu (Kenya). Characteristic debris accumulations on the beach surface at Tamil Nadu (India) showed the impact of three tsunami waves. In this area, the tsunami climbed ~5 m up the beach; the last traces of a tsunami wave were found ~580 m away from the shoreline. Palm trees indicated an overland flow depth of 3.5 m, ~50 m from the shoreline. The tsunami deposits were up to 30 cm thick. They had an erosional base to the underlying soil and pre-tsunami beach deposits and were made up of moderately well- to well-sorted coarse and medium sand. The sand sheet thins inland, but without a decrease in grain size. Three distinct layers could be identified within the tsunami deposit. The lower one occasionally displayed cross-bedding with foresets dipping landward indicating deposition during run-up. The two upper layers were graded or parallel-laminated without indicators of flow directions. The boundaries between the different layers were marked by dark laminae, rich in heavy minerals. Also, the presence of benthic foraminifera indicates entrainment of sediment into the water column by the incoming tsunami wave in water depths less than 30 m. On beaches between Malindi and Lamu, Kenya, the traces of only one tsunami wave could be found, which attained a run-up height of about 3 m and traveled ~35 m inland with respect to the tidal stage at tsunami impact. The tsunami sediments consist of one layer of fine sand and are predominantly composed of heavy minerals supplied to the sea by nearby rivers. A slight fining </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016RPPh...79i6601A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016RPPh...79i6601A">Nonlinear physics of electrical wave propagation in the heart: a review</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Alonso, Sergio; Bär, Markus; Echebarria, Blas 2016-09-01 The beating of the heart is a synchronized contraction of muscle cells (myocytes) that is triggered by a periodic sequence of electrical waves (action potentials) originating in the sino-atrial node and propagating over the atria and the ventricles. Cardiac arrhythmias like atrial and ventricular fibrillation (AF,VF) or ventricular tachycardia (VT) are caused by disruptions and instabilities of these electrical excitations, that lead to the emergence of rotating waves (VT) and turbulent wave patterns (AF,VF). Numerous simulation and experimental studies during the last 20 years have addressed these topics. In this review we focus on the nonlinear dynamics of wave propagation in the heart with an emphasis on the theory of pulses, spirals and scroll waves and their instabilities in excitable media with applications to cardiac modeling. After an introduction into electrophysiological models for action potential propagation, the modeling and analysis of spatiotemporal alternans, spiral and scroll meandering, spiral breakup and scroll wave instabilities like negative line tension and sproing are reviewed in depth and discussed with emphasis on their impact for cardiac arrhythmias. </li> <li> <a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/15620512','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/15620512">Control of wave propagation in a biological excitable medium by an external electric field.</a> <a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a> Sebestikova, Lenka; Slamova, Elena; Sevcikova, Hana 2005-03-01 We present an experimental evidence of effects of external electric fields (EFs) on the velocity of pulse waves propagating in a biological excitable medium. The excitable medium used is formed by a layer of starving cells of Dictyostelium discoideum through which the waves of increased concentration of cAMP propagate by reaction-diffusion mechanism. External dc EFs of low intensities (up to 5 V/cm) are shown to speed up the propagation of cAMP waves towards the positive electrode and slow it down towards the negative electrode. Electric fields were also found to support an emergence of new centers, emitting cAMP waves, in front of cAMP waves propagating towards the negative electrode. </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li class="active">23</li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>25</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> </div> <div id="page_24" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li class="active">24</li> <li><a href="#" onclick='return showDiv("page_25");'>25</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="461"> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017JMPSo.106...34D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017JMPSo.106...34D">Wave propagation in elastic and damped structures with stabilized negative-stiffness components</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Drugan, W. J. 2017-09-01 Effects on wave propagation achievable by introduction of a negative-stiffness component are investigated via perhaps the simplest discrete repeating element that can remain stable in the component's presence. When the system is elastic, appropriate tuning of the stabilized component's negative stiffness introduces a no-pass zone theoretically extending from zero to an arbitrarily high frequency, tunable by a mass ratio adjustment. When the negative-stiffness component is tuned to the system's stability limit and a mass ratio is sufficiently small, the system restricts propagation to waves of approximately a single arbitrary frequency, adjustable by tuning the stiffness ratio of the positive-stiffness components. The elastic system's general solutions are closed-form and transparent. When damping is added, the general solutions are still closed-form, but so complex that they do not clearly display how the negative stiffness component affects the system's response and how it should best be tuned to achieve desired effects. Approximate solutions having these features are obtained via four perturbation analyses: one for long wavelengths; one for small damping; and two for small mass ratios. The long-wavelengths solution shows that appropriate tuning of the negative-stiffness component can prevent propagation of long-wavelength waves. The small damping solution shows that the zero-damping low-frequency no-pass zone remains, while waves that do propagate are highly damped when a mass ratio is made small. Finally, very interesting effects are achievable at the full system's stability limit. For small mass ratios, the wavelength range of waves prohibited from propagation can be adjusted, from all to none, by tuning the system's damping: When one mass ratio is small, all waves with wavelengths larger than an arbitrary damping-adjusted value can be prohibited from propagation, while when the inverse of this mass ratio is small, all waves with wavelengths outside an </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AGUFMNH53A..08Y','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AGUFMNH53A..08Y">Recent Advances in Remote Sensing of Natural Hazards-Induced Atmospheric and Ionospheric Perturbations</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Yang, Y. M.; Komjathy, A.; Meng, X.; Verkhoglyadova, O. P.; Langley, R. B.; Mannucci, A. J. 2015-12-01 Traveling ionospheric disturbances (TIDs) induced by acoustic-gravity waves in the neutral atmosphere have significant impact on trans-ionospheric radio waves such as Global Navigation Satellite System (GNSS, including Global Position System (GPS)) measurements. Natural hazards and solid Earth events, such as earthquakes, tsunamis and volcanic eruptions are actual sources that may trigger acoustic and gravity waves resulting in traveling ionospheric disturbances (TIDs) in the upper atmosphere. Trans-ionospheric radio wave measurements sense the total electron content (TEC) along the signal propagation path. In this research, we introduce a novel GPS-based detection and estimation technique for remote sensing of atmospheric wave-induced TIDs including space weather phenomena induced by major natural hazard events, using TEC time series collected from worldwide ground-based dual-frequency GNSS (including GPS) receiver networks. We demonstrate the ability of using ground- and space-based dual-frequency GPS measurements to detect and monitor tsunami wave propagation from the 2011 Tohoku-Oki earthquake and tsunami. Major wave trains with different propagation speeds and wavelengths were identified through analysis of the GPS remote sensing observations. Dominant physical characteristics of atmospheric wave-induced TIDs are found to be associated with specific tsunami propagations and oceanic Rayleigh waves. In this research, we compared GPS-based observations, corresponding model simulations and tsunami wave propagation. Results are shown to lead to a better understanding of the tsunami-induced ionosphere responses. Based on current distribution of Plate Boundary Observatory GPS stations, the results indicate that tsunami-induced TIDs may be detected about 60 minutes prior to tsunamis arriving at the U.S. west coast. It is expected that this GNSS-based technology will become an integral part of future early-warning systems. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1997PhDT.......302H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1997PhDT.......302H">Microstructure of wave propagation during combustion synthesis of advanced materials: Experiments and theory</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Hwang, Stephen Combustion synthesis (CS) is an attractive method for producing advanced materials, including ceramics, intermetallics, and composites. In this process, after initiation by an external heat source, a highly exothermic reaction propagates through the sample in a self-sustained combustion wave. The process offers the possibility of producing materials with novel structures and properties. At conventional magnifications and imaging rates, the combustion wave appears to propagate in a planar, steady manner. However, using higher magnifications (>400X) and imaging rates (1000 frames/sec), fluctuations in the shape and propagation of the combustion front were observed. These variations in local conditions (i.e., the microstructure of the combustion wave) can influence the microstructure and properties of materials produced by combustion synthesis. In this work, the microstructure of wave propagation during combustion synthesis is investigated experimentally and theoretically. Using microscopic high-speed imaging, the spatial and temporal fluctuations of the combustion front shape and propagation were investigated. New image analysis methods were developed to characterize the heterogeneity of the combustion front quantitatively. The initial organization of the reaction medium was found to affect the heterogeneity of the combustion wave. Moreover, at the microscopic level, two different regimes of combustion propagation were observed. In the quasihomogeneous mechanism, the microstructure of the combustion wave resembles what is viewed macroscopically, and steady, planar propagation is observed. In the relay-race mechanism, while planar at the macroscopic level, the combustion front profiles are irregularly shaped, with arc-shaped convexities and concavities at the microscopic level. Also, the reaction front propagates as a series of rapid jumps and hesitations. Based on the combustion wave microstructure, new criteria were developed to determine the boundaries between </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018SMaS...27a5030A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018SMaS...27a5030A">Application of magnetoelastic materials in spatiotemporally modulated phononic crystals for nonreciprocal wave propagation</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Ansari, M. H.; Attarzadeh, M. A.; Nouh, M.; Karami, M. Amin 2018-01-01 In this paper, a physical platform is proposed to change the properties of phononic crystals in space and time in order to achieve nonreciprocal wave transmission. The utilization of magnetoelastic materials in elastic phononic systems is studied. Material properties of magnetoelastic materials change significantly with an external magnetic field. This property is used to design systems with a desired wave propagation pattern. The properties of the magnetoelastic medium are changed in a traveling wave pattern, which changes in both space and time. A phononic crystal with such a modulation exhibits one-way wave propagation behavior. An extended transfer matrix method (TMM) is developed to model a system with time varying properties. The stop band and the pass band of a reciprocal and a nonreciprocal bar are found using this method. The TMM is used to find the transfer function of a magnetoelastic bar. The obtained results match those obtained via the theoretical Floquet-Bloch approach and numerical simulations. It is shown that the stop band in the transfer function of a system with temporal varying property for the forward wave propagation is different from the same in the backward wave propagation. The proposed configuration enables the physical realization of a class of smart structures that incorporates nonreciprocal wave propagation. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AGUFMNH52A..07C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUFMNH52A..07C">Lessons for tsunami risk mitigation from recent events occured in Chile: research findings for alerting and evacuation from interdisciplinary perspectives</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Cienfuegos, R.; Catalan, P. A.; Leon, J.; Gonzalez, G.; Repetto, P.; Urrutia, A.; Tomita, T.; Orellana, V. 2016-12-01 In the wake of the 2010 tsunami that hit Chile, a major public effort to promote interdisciplinary disaster reseach was undertaken by the Comisión Nacional de Investigación Científica y Tecnológica (Conicyt) allocating funds to create the Center for Integrated Research on Natural Risks Management (CIGIDEN). This effort has been key in promoting associativity between national and international research teams in order to transform the frequent occurrence of extreme events that affect Chile into an opportunity for interdisciplinary research. In this presentation we will summarize some of the fundamental research findings regarding tsunami forecasting, alerting, and evacuation processes based on interdisciplinary field work campaigns and modeling efforts conducted in the wake of the three most recent destructive events that hit Chile in 2010, 2014, and 2015. One of the main results that we shall emphatize from these findings, is that while research and operational efforts to model and forecast tsunamis are important, technological positivisms should not undermine educational efforts that have proved to be effective in reducing casualties due to tsunamis in the near field. Indeed, in recent events that hit Chile, first tsunami waves reached the adjacent generation zones in time scales comparable with the required time for data gathering and modeling even for the most sophisticated early warning tsunami algorithms currently available. The latter emphasizes self-evacuation from coastal areas, while forecasting and monitoring tsunami hazards remain very important for alerting more distant areas, and are essential for alert cancelling especially when shelf and embayment resonance, and edge wave propagation may produce destructive late tsunami arrivals several hours after the nucleation of the earthquake. By combining some of the recent evidence we have gathered in Chile on seismic source uncertainities (both epistemic and aleatoric), tsunami hydrodynamics, the response </li> <li> <a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/22599157-propagation-electromagnetic-waves-weak-collisional-fully-ionized-dusty-plasma','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/22599157-propagation-electromagnetic-waves-weak-collisional-fully-ionized-dusty-plasma">Propagation of electromagnetic waves in a weak collisional and fully ionized dusty plasma</a> <a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a> Jia, Jieshu; Yuan, Chengxun, E-mail: yuancx@hit.edu.cn; Gao, Ruilin 2016-04-15 The propagation properties of electromagnetic (EM) waves in fully ionized dusty plasmas is the subject of this study. The dielectric relationships for EM waves propagating in a fully ionized dusty plasma was derived from the Boltzmann distribution law, taking into consideration the collision and charging effects of the dust grains. The propagation properties of the EM waves in a dusty plasma were numerically calculated and studied. The study results indicated that the dusty grains with an increased radius and charge were more likely to impede the penetration of EM waves. Dust grains with large radii and high charge cause themore » attenuation of the EM wave in the dusty plasma. The different density of the dust in the plasma appeared to have no obvious effect on the transmission of the EM waves. The propagation of the EM waves in a weakly ionized dusty plasma varies from that in a fully ionized dusty plasma. The results are helpful to analyze the effects of dust in dusty plasmas and also provide a theoretical basis for future studies.« less </li> <li> <a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19940004262&hterms=Lamb&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3DLamb','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19940004262&hterms=Lamb&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3DLamb">Experimental and theoretical study of Rayleigh-Lamb wave propagation</a> <a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a> Rogers, Wayne P.; Datta, Subhendu K.; Ju, T. H. 1990-01-01 Many space structures, such as the Space Station Freedom, contain critical thin-walled components. The structural integrity of thin-walled plates and shells can be monitored effectively using acoustic emission and ultrasonic testing in the Rayleigh-Lamb wave frequency range. A new PVDF piezoelectric sensor has been developed that is well suited to remote, inservice nondestructive evaluation of space structures. In the present study the new sensor was used to investigate Rayleigh-Lamb wave propagation in a plate. The experimental apparatus consisted of a glass plate (2.3 m x 25.4 mm x 5.6 mm) with PVDF sensor (3 mm diam.) mounted at various positions along its length. A steel ball impact served as a simulated acoustic emission source, producing surface waves, shear waves and longitudinal waves with dominant frequencies between 1 kHz and 200 kHz. The experimental time domain wave-forms were compared with theoretical predictions of the wave propagation in the plate. The model uses an analytical solution for the Green's function and the measured response at a single position to predict response at any other position in the plate. Close agreement was found between the experimental and theoretical results. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19950013131','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19950013131">Simulation of wave propagation in three-dimensional random media</a> <a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a> Coles, William A.; Filice, J. P.; Frehlich, R. G.; Yadlowsky, M. 1993-01-01 Quantitative error analysis for simulation of wave propagation in three dimensional random media assuming narrow angular scattering are presented for the plane wave and spherical wave geometry. This includes the errors resulting from finite grid size, finite simulation dimensions, and the separation of the two-dimensional screens along the propagation direction. Simple error scalings are determined for power-law spectra of the random refractive index of the media. The effects of a finite inner scale are also considered. The spatial spectra of the intensity errors are calculated and compared to the spatial spectra of intensity. The numerical requirements for a simulation of given accuracy are determined for realizations of the field. The numerical requirements for accurate estimation of higher moments of the field are less stringent. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AGUFMNH43B1845M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUFMNH43B1845M">A computationally fast, reduced model for simulating landslide dynamics and tsunamis generated by landslides in natural terrains</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Mohammed, F. 2016-12-01 Landslide hazards such as fast-moving debris flows, slow-moving landslides, and other mass flows cause numerous fatalities, injuries, and damage. Landslide occurrences in fjords, bays, and lakes can additionally generate tsunamis with locally extremely high wave heights and runups. Two-dimensional depth-averaged models can successfully simulate the entire lifecycle of the three-dimensional landslide dynamics and tsunami propagation efficiently and accurately with the appropriate assumptions. Landslide rheology is defined using viscous fluids, visco-plastic fluids, and granular material to account for the possible landslide source materials. Saturated and unsaturated rheologies are further included to simulate debris flow, debris avalanches, mudflows, and rockslides respectively. The models are obtained by reducing the fully three-dimensional Navier-Stokes equations with the internal rheological definition of the landslide material, the water body, and appropriate scaling assumptions to obtain the depth-averaged two-dimensional models. The landslide and tsunami models are coupled to include the interaction between the landslide and the water body for tsunami generation. The reduced models are solved numerically with a fast semi-implicit finite-volume, shock-capturing based algorithm. The well-balanced, positivity preserving algorithm accurately accounts for wet-dry interface transition for the landslide runout, landslide-water body interface, and the tsunami wave flooding on land. The models are implemented as a General-Purpose computing on Graphics Processing Unit-based (GPGPU) suite of models, either coupled or run independently within the suite. The GPGPU implementation provides up to 1000 times speedup over a CPU-based serial computation. This enables simulations of multiple scenarios of hazard realizations that provides a basis for a probabilistic hazard assessment. The models have been successfully validated against experiments, past studies, and field data </li> <li> <a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70035147','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70035147">Scenarios for earthquake-generated tsunamis on a complex tectonic area of diffuse deformation and low velocity: The Alboran Sea, Western Mediterranean</a> <a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a> Alvarez-Gomez, J. A.; Aniel-Quiroga, I.; Gonzalez, M.; Olabarrieta, Maitane; Carreno, E. 2011-01-01 The tsunami impact on the Spanish and North African coasts of the Alboran Sea generated by several reliable seismic tsunamigenic sources in this area was modeled. The tectonic setting is complex and a study of the potential sources from geological data is basic to obtain probable source characteristics. The tectonic structures considered in this study as potentially tsunamigenic are: the Alboran Ridge associated structures, the Carboneras Fault Zone and the Yusuf Fault Zone. We characterized 12 probable tsunamigenic seismic sources in the Alboran Basin based on the results of recent oceanographical studies. The strain rate in the area is low and therefore its seismicity is moderate and cannot be used to infer characteristics of the major seismic sources. These sources have been used as input for the numerical simulation of the wave propagation, based on the solution of the nonlinear shallow water equations through a finite-difference technique. We calculated the Maximum Wave Elevations, and Tsunami Travel Times using the numerical simulations. The results are shown as maps and profiles along the Spanish and African coasts. The sources associated with the Alboran Ridge show the maximum potential to generate damaging tsunamis, with maximum wave elevations in front of the coast exceeding 1.5 m. The Carboneras and Yusuf faults are not capable of generating disastrous tsunamis on their own, although their proximity to the coast could trigger landslides and associated sea disturbances. The areas which are more exposed to the impact of tsunamis generated in the Alboran Sea are the Spanish coast between Malaga and Adra, and the African coast between Alhoceima and Melilla. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AIPC.1899f0006Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AIPC.1899f0006Z">Mathematical investigation of tsunami-like long waves interaction with submerge dike of different thickness</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Zhiltsov, Konstantin; Kostyushin, Kirill; Kagenov, Anuar; Tyryshkin, Ilya 2017-11-01 This paper presents a mathematical investigation of the interaction of a long tsunami-type wave with a submerge dike. The calculations were performed by using the freeware package OpenFOAM. Unsteady two-dimensional Navier-Stokes equations were used for mathematical modeling of incompressible two-phase medium. The Volume of Fluid (VOF) method is used to capture the free surface of a liquid. The effects caused by long wave of defined amplitude motion through a submerged dike of varying thickness were discussed in detail. Numerical results show that after wave passing through the barrier, multiple vortex structures were formed behind. Intensity of vortex depended on the size of the barrier. The effectiveness of the submerge barrier was estimated by evaluating the wave reflection and transmission coefficients using the energy integral method. Then, the curves of the dependences of the reflection and transmission coefficients were obtained for the interaction of waves with the dike. Finally, it was confirmed that the energy of the wave could be reduced by more than 50% when it passed through the barrier. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012A%26A...538A..79N','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012A%26A...538A..79N">Modification of wave propagation and wave travel-time by the presence of magnetic fields in the solar network atmosphere</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Nutto, C.; Steiner, O.; Schaffenberger, W.; Roth, M. 2012-02-01 Context. Observations of waves at frequencies above the acoustic cut-off frequency have revealed vanishing wave travel-times in the vicinity of strong magnetic fields. This detection of apparently evanescent waves, instead of the expected propagating waves, has remained a riddle. Aims: We investigate the influence of a strong magnetic field on the propagation of magneto-acoustic waves in the atmosphere of the solar network. We test whether mode conversion effects can account for the shortening in wave travel-times between different heights in the solar atmosphere. Methods: We carry out numerical simulations of the complex magneto-atmosphere representing the solar magnetic network. In the simulation domain, we artificially excite high frequency waves whose wave travel-times between different height levels we then analyze. Results: The simulations demonstrate that the wave travel-time in the solar magneto-atmosphere is strongly influenced by mode conversion. In a layer enclosing the surface sheet defined by the set of points where the Alfvén speed and the sound speed are equal, called the equipartition level, energy is partially transferred from the fast acoustic mode to the fast magnetic mode. Above the equipartition level, the fast magnetic mode is refracted due to the large gradient of the Alfvén speed. The refractive wave path and the increasing phase speed of the fast mode inside the magnetic canopy significantly reduce the wave travel-time, provided that both observing levels are above the equipartition level. Conclusions: Mode conversion and the resulting excitation and propagation of fast magneto-acoustic waves is responsible for the observation of vanishing wave travel-times in the vicinity of strong magnetic fields. In particular, the wave propagation behavior of the fast mode above the equipartition level may mimic evanescent behavior. The present wave propagation experiments provide an explanation of vanishing wave travel-times as observed with multi </li> <li> <a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28343360','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28343360">Tsunami run-up and inundation along the coast of Sabah and Sarawak, Malaysia due to a potential Brunei submarine mass failure.</a> <a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a> Tan, Wai Kiat; Teh, Su Yean; Koh, Hock Lye 2017-07-01 Submarine landslides, also known as submarine mass failures (SMFs), are major natural marine disasters that could critically damage coastal facilities such as nuclear power plants and oil and gas platforms. It is therefore essential to investigate submarine landslides for potential tsunami hazard assessment. Three-dimensional seismic data from offshore Brunei have revealed a giant seabed mass deposited by a previous SMF. The submarine mass extends over 120 km from the continental slope of the Baram Canyon at 200 m water depth to the deep basin floor of the Northwest Borneo Trough. A suite of in-house two-dimensional depth-averaged tsunami simulation model TUNA (Tsunami-tracking Utilities and Application) is developed to assess the vulnerability of coastal communities in Sabah and Sarawak subject to potential SMF tsunami. The submarine slide is modeled as a rigid body moving along a planar slope with the center of mass motion parallel to the planar slope and subject to external forces due to added mass, gravity, and dissipation. The nonlinear shallow water equations are utilized to simulate tsunami propagation from deepwater up to the shallow offshore areas. A wetting-drying algorithm is used when a tsunami wave reaches the shoreline to compute run up of tsunami along the shoreline. Run-up wave height and inundation maps are provided for seven densely populated locations in Sabah and Sarawak to highlight potential risks at each location, subject to two scenarios of slide slopes: 2° and 4°. The first wave may arrive at Kudat as early as 0.4 h after the SMF, giving local communities little time to evacuate. Over a small area, maximum inundated depths reaching 20.3 m at Kudat, 26.1 m at Kota Kinabalu, and 15.5 m at Miri are projected, while the maximum inundation distance of 4.86 km is expected at Miri due to its low-lying coast. In view of the vulnerability of some locations to the SMF tsunami, it is important to develop and implement community resilience </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011AGUFM.U41D..03Y','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011AGUFM.U41D..03Y">Source Mechanism and Near-field Characteristics of the 2011 Tohoku-oki Tsunami</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Yamazaki, Y.; Cheung, K.; Lay, T. 2011-12-01 The Tohoku-oki great earthquake ruptured the megathrust fault offshore of Miyagi and Fukushima in Northeast Honshu with moment magnitude of Mw 9.0 on March 11, 2011, and generated strong shaking across the region. The resulting tsunami devastated the northeastern Japan coasts and damaged coastal infrastructure across the Pacific. The extensive global seismic networks, dense geodetic instruments, well-positioned buoys and wave gauges, and comprehensive runup records along the northeast Japan coasts provide datasets of unprecedented quality and coverage for investigation of the tsunami source mechanism and near-field wave characteristics. Our finite-source model reconstructs detailed source rupture processes by inversion of teleseismic P waves recorded around the globe. The finite-source solution is validated through comparison with the static displacements recoded at the ARIA (JPL-GSI) GPS stations and models obtained by inversion of high-rate GPS observations. The rupture model has two primary slip regions, near the hypocenter and along the trench; the maximum slip is about 60 m near the trench. Together with the low rupture velocity, the Tohoku-oki event has characteristics in common with tsunami earthquakes, although it ruptured across the entire megathrust. Superposition of the deformation of the subfaults from the planar fault model according to their rupture initiation and rise times specifies the seafloor vertical displacement and velocity for tsunami modeling. We reconstruct the 2011 Tohoku-oki tsunami from the time histories of the seafloor deformation using the dispersive long-wave model NEOWAVE (Non-hydrostatic Evolution of Ocean WAVEs). The computed results are compared with data from six GPS gauges and three wave gauges near the source at 120~200-m and 50-m water depth, as well as DART buoys positioned across the Pacific. The shock-capturing model reproduces near-shore tsunami bores and the runup data gathered by the 2011 Tohoku Earthquake Tsunami Joint </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2007Geo....35...25M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2007Geo....35...25M">Unique and remarkable dilatometer measurements of pyroclastic flow generated tsunamis</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Mattioli, G. S.; Voight, B.; Linde, A. T.; Sacks, I. S.; Watts, P.; Widiwijayanti, C.; Young, S. R.; Hidayat, D.; Elsworth, D.; Malin, P. E.; Shalev, E.; van Boskirk, E.; Johnston, W.; Sparks, R. S. J.; Neuberg, J.; Bass, V.; Dunkley, P.; Herd, R.; Syers, T.; Williams, P.; Williams, D. 2007-01-01 Pyroclastic flows entering the sea may cause tsunamis at coastal volcanoes worldwide, but geophysically monitored field occurrences are rare. We document the process of tsunami generation during a prolonged gigantic collapse of the Soufrière Hills volcano lava dome on Montserrat on 12 13 July 2003. Tsunamis were initiated by large-volume pyroclastic flows entering the ocean. We reconstruct the collapse from seismic records and report unique and remarkable borehole dilatometer observations, which recorded clearly the passage of wave packets at periods of 250 500 s over several hours. Strain signals are consistent in period and amplitude with water loading from passing tsunamis; each wave packet can be correlated with individual pyroclastic flow packages recorded by seismic data, proving that multiple tsunamis were initiated by pyroclastic flows. Any volcano within a few kilometers of water and capable of generating hot pyroclastic flows or cold debris flows with volumes greater than 5 × 106 m3 may generate significant and possibly damaging tsunamis during future eruptions. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012AGUFMOS21G..06G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012AGUFMOS21G..06G">In Search of the Largest Possible Tsunami: An Example Following the 2011 Japan Tsunami</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Geist, E. L.; Parsons, T. 2012-12-01 Many tsunami hazard assessments focus on estimating the largest possible tsunami: i.e., the worst-case scenario. This is typically performed by examining historic and prehistoric tsunami data or by estimating the largest source that can produce a tsunami. We demonstrate that worst-case assessments derived from tsunami and tsunami-source catalogs are greatly affected by sampling bias. Both tsunami and tsunami sources are well represented by a Pareto distribution. It is intuitive to assume that there is some limiting size (i.e., runup or seismic moment) for which a Pareto distribution is truncated or tapered. Likelihood methods are used to determine whether a limiting size can be determined from existing catalogs. Results from synthetic catalogs indicate that several observations near the limiting size are needed for accurate parameter estimation. Accordingly, the catalog length needed to empirically determine the limiting size is dependent on the difference between the limiting size and the observation threshold, with larger catalog lengths needed for larger limiting-threshold size differences. Most, if not all, tsunami catalogs and regional tsunami source catalogs are of insufficient length to determine the upper bound on tsunami runup. As an example, estimates of the empirical tsunami runup distribution are obtained from the Miyako tide gauge station in Japan, which recorded the 2011 Tohoku-oki tsunami as the largest tsunami among 51 other events. Parameter estimation using a tapered Pareto distribution is made both with and without the Tohoku-oki event. The catalog without the 2011 event appears to have a low limiting tsunami runup. However, this is an artifact of undersampling. Including the 2011 event, the catalog conforms more to a pure Pareto distribution with no confidence in estimating a limiting runup. Estimating the size distribution of regional tsunami sources is subject to the same sampling bias. Physical attenuation mechanisms such as wave breaking </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011AGUFMNH14A..05C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011AGUFMNH14A..05C">Modeling of the 2011 Tohoku-oki Tsunami and its Impacts on Hawaii</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Cheung, K.; Yamazaki, Y.; Roeber, V.; Lay, T. 2011-12-01 The 2011 Tohoku-oki great earthquake (Mw 9.0) generated a destructive tsunami along the entire Pacific coast of northeastern Japan. The tsunami, which registered 6.7 m amplitude at a coastal GPS gauge and 1.75 m at an open-ocean DART buoy, triggered warnings across the Pacific. The waves reached Hawaii 7 hours after the earthquake and caused localized damage and persistent coastal oscillations along the island chain. Several tide gauges and a DART buoy west of Hawaii Island recorded clear signals of the tsunami. The Tsunami Observer Program of Hawaii State Civil Defense immediately conducted field surveys to gather runup and inundation data on Kauai, Oahu, Maui, and Hawaii Island. The extensive global seismic networks and geodetic instruments allows evaluation and validation of finite fault solutions for the tsunami modeling. We reconstruct the 2011 Tohoku-oki tsunami using the long-wave model NEOWAVE (Non-hydrostatic Evolution of Ocean WAVEs) and a finite fault solution based on inversion of teleseismic P waves. The depth-integrated model describes dispersive waves through the non-hydrostatic pressure and vertical velocity, which also account for tsunami generation from time histories of seafloor deformation. The semi-implicit, staggered finite difference model captures flow discontinuities associated with bores or hydraulic jumps through the momentum-conserved advection scheme. Four levels of two-way nested grids in spherical coordinates allow description of tsunami evolution processes of different time and spatial scales for investigation of the impacts around the Hawaiian Islands. The model results are validated with DART data across the Pacific as well as tide gauge and runup measurements in Hawaii. Spectral analysis of the computed surface elevation reveals a series of resonance modes over the insular shelf and slope complex along the archipelago. Resonance oscillations provide an explanation for the localized impacts and the persistent wave activities in the </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018MS%26E..300a2049K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018MS%26E..300a2049K">Modification of 2-D Time-Domain Shallow Water Wave Equation using Asymptotic Expansion Method</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Khairuman, Teuku; Nasruddin, MN; Tulus; Ramli, Marwan 2018-01-01 Generally, research on the tsunami wave propagation model can be conducted by using a linear model of shallow water theory, where a non-linear side on high order is ignored. In line with research on the investigation of the tsunami waves, the Boussinesq equation model underwent a change aimed to obtain an improved quality of the dispersion relation and non-linearity by increasing the order to be higher. To solve non-linear sides at high order is used a asymptotic expansion method. This method can be used to solve non linear partial differential equations. In the present work, we found that this method needs much computational time and memory with the increase of the number of elements. </li> <li> <a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/21567649-spatial-damping-propagating-kink-waves-prominence-threads','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/21567649-spatial-damping-propagating-kink-waves-prominence-threads">SPATIAL DAMPING OF PROPAGATING KINK WAVES IN PROMINENCE THREADS</a> <a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a> Soler, R.; Oliver, R.; Ballester, J. L., E-mail: roberto.soler@wis.kuleuven.be Transverse oscillations and propagating waves are frequently observed in threads of solar prominences/filaments and have been interpreted as kink magnetohydrodynamic (MHD) modes. We investigate the spatial damping of propagating kink MHD waves in transversely nonuniform and partially ionized prominence threads. Resonant absorption and ion-neutral collisions (Cowling's diffusion) are the damping mechanisms taken into account. The dispersion relation of resonant kink waves in a partially ionized magnetic flux tube is numerically solved by considering prominence conditions. Analytical expressions of the wavelength and damping length as functions of the kink mode frequency are obtained in the thin tube and thin boundary approximations.more » For typically reported periods of thread oscillations, resonant absorption is an efficient mechanism for the kink mode spatial damping, while ion-neutral collisions have a minor role. Cowling's diffusion dominates both the propagation and damping for periods much shorter than those observed. Resonant absorption may explain the observed spatial damping of kink waves in prominence threads. The transverse inhomogeneity length scale of the threads can be estimated by comparing the observed wavelengths and damping lengths with the theoretically predicted values. However, the ignorance of the form of the density profile in the transversely nonuniform layer introduces inaccuracies in the determination of the inhomogeneity length scale.« less </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013SCPMA..56.1542Q','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013SCPMA..56.1542Q">Propagation of elastic wave in nanoporous material with distributed cylindrical nanoholes</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Qiang, FangWei; Wei, PeiJun; Liu, XiQiang 2013-08-01 The effective propagation constants of plane longitudinal and shear waves in nanoporous material with random distributed parallel cylindrical nanoholes are studied. The surface elastic theory is used to consider the surface stress effects and to derive the nontraditional boundary condition on the surface of nanoholes. The plane wave expansion method is used to obtain the scattering waves from the single nanohole. The multiple scattering effects are taken into consideration by summing the scattered waves from all scatterers and performing the configuration averaging of random distributed scatterers. The effective propagation constants of coherent waves along with the associated dynamic effective elastic modulus are numerically evaluated. The influences of surface stress are discussed based on the numerical results. </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li class="active">24</li> <li><a href="#" onclick='return showDiv("page_25");'>25</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> </div> <div id="page_25" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li class="active">25</li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="481"> <li> <a target="_blank" onclick="trackOutboundLink('http://www.dtic.mil/docs/citations/AD1046558','DTIC-ST'); return false;" href="http://www.dtic.mil/docs/citations/AD1046558">Quantifying Electromagnetic Wave Propagation Environment Using Measurements From A Small Buoy</a> <a target="_blank" href="http://www.dtic.mil/">DTIC Science & Technology</a> 2017-06-01 ELECTROMAGNETIC WAVE PROPAGATION ENVIRONMENT USING MEASUREMENTS FROM A SMALL BUOY by Andrew E. Sweeney June 2017 Thesis Advisor: Qing Wang...TYPE AND DATES COVERED Master’s thesis 4. TITLE AND SUBTITLE QUANTIFYING ELECTROMAGNETIC WAVE PROPAGATION ENVIRONMENT USING MEASUREMENTS FROM A...the Coupled Air Sea Processes and Electromagnetic (EM) ducting Research (CASPER), to understand air-sea interaction processes and their representation </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017PhyEd..52b5001S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017PhyEd..52b5001S">Laboratory model of the cardiovascular system for experimental demonstration of pulse wave propagation</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Stojadinović, Bojana; Nestorović, Zorica; Djurić, Biljana; Tenne, Tamar; Zikich, Dragoslav; Žikić, Dejan 2017-03-01 The velocity by which a disturbance moves through the medium is the wave velocity. Pulse wave velocity is among the key parameters in hemodynamics. Investigation of wave propagation through the fluid-filled elastic tube has a great importance for the proper biophysical understanding of the nature of blood flow through the cardiovascular system. Here, we present a laboratory model of the cardiovascular system. We have designed an experimental setup which can help medical and nursing students to properly learn and understand basic fluid hemodynamic principles, pulse wave and the phenomenon of wave propagation in blood vessels. Demonstration of wave propagation allowed a real time observation of the formation of compression and expansion waves by students, thus enabling them to better understand the difference between the two waves, and also to measure the pulse wave velocity for different fluid viscosities. The laboratory model of the cardiovascular system could be useful as an active learning methodology and a complementary tool for understanding basic principles of hemodynamics. </li> <li> <a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/pages/biblio/1259966-conical-wave-propagation-diffraction-two-dimensional-hexagonally-packed-granular-lattices','SCIGOV-DOEP'); return false;" href="https://www.osti.gov/pages/biblio/1259966-conical-wave-propagation-diffraction-two-dimensional-hexagonally-packed-granular-lattices">Conical wave propagation and diffraction in two-dimensional hexagonally packed granular lattices</a> <a target="_blank" href="http://www.osti.gov/pages">DOE PAGES</a> Chong, C.; Kevrekidis, P. G.; Ablowitz, M. J.; ... 2016-01-25 We explore linear and nonlinear mechanisms for conical wave propagation in two-dimensional lattices in the realm of phononic crystals. As a prototypical example, a statically compressed granular lattice of spherical particles arranged in a hexagonal packing configuration is analyzed. Upon identifying the dispersion relation of the underlying linear problem, the resulting diffraction properties are considered. Analysis both via a heuristic argument for the linear propagation of a wave packet and via asymptotic analysis leading to the derivation of a Dirac system suggests the occurrence of conical diffraction. This analysis is valid for strong precompression, i.e., near the linear regime. Formore » weak precompression, conical wave propagation is still possible, but the resulting expanding circular wave front is of a nonoscillatory nature, resulting from the complex interplay among the discreteness, nonlinearity, and geometry of the packing. Lastly, the transition between these two types of propagation is explored.« less </li> <li> <a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/877842','SCIGOV-STC'); return false;" href="https://www.osti.gov/servlets/purl/877842">Modeling Propagation of Shock Waves in Metals</a> <a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a> Howard, W M; Molitoris, J D 2005-08-19 We present modeling results for the propagation of strong shock waves in metals. In particular, we use an arbitrary Lagrange Eulerian (ALE3D) code to model the propagation of strong pressure waves (P {approx} 300 to 400 kbars) generated with high explosives in contact with aluminum cylinders. The aluminum cylinders are assumed to be both flat-topped and have large-amplitude curved surfaces. We use 3D Lagrange mechanics. For the aluminum we use a rate-independent Steinberg-Guinan model, where the yield strength and shear modulus depend on pressure, density and temperature. The calculation of the melt temperature is based on the Lindermann law. Atmore » melt the yield strength and shear modulus is set to zero. The pressure is represented as a seven-term polynomial as a function of density. For the HMX-based high explosive, we use a JWL, with a program burn model that give the correct detonation velocity and C-J pressure (P {approx} 390 kbars). For the case of the large-amplitude curved surface, we discuss the evolving shock structure in terms of the early shock propagation experiments by Sakharov.« less </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2006AIPC..845..319H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2006AIPC..845..319H">Modeling Propagation of Shock Waves in Metals</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Howard, W. M.; Molitoris, J. D. 2006-07-01 We present modeling results for the propagation of strong shock waves in metals. In particular, we use an arbitrary Lagrange Eulerian (ALE3D) code to model the propagation of strong pressure waves (P ˜ 300 to 400 kbars) generated with high explosives in contact with aluminum cylinders. The aluminum cylinders are assumed to be both flat-topped and have large-amplitude curved surfaces. We use 3D Lagrange mechanics. For the aluminum we use a rate-independent Steinberg-Guinan model, where the yield strength and shear modulus depend on pressure, density and temperature. The calculation of the melt temperature is based on the Lindermann law. At melt the yield strength and shear modulus is set to zero. The pressure is represented as a seven-term polynomial as a function of density. For the HMX-based high explosive, we use a JWL, with a program burn model that give the correct detonation velocity and C-J pressure (P ˜ 390 kbars). For the case of the large-amplitude curved surface, we discuss the evolving shock structure in terms of the early shock propagation experiments by Sakharov. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2006cosp...36..465N','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2006cosp...36..465N">Initial tsunami signals in the lithosphere-ocean-atmosphere medium</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Novik, O.; Ershov, S.; Mikhaylovskaya, I. Satellite and ground based instrumentations for monitoring of dynamical processes under the Ocean floor 3 4 of the Earth surface and resulting catastrophic events should be adapted to unknown physical nature of transformation of the oceanic lithosphere s energy of seismogenic deformations into measurable acoustic electromagnetic EM temperature and hydrodynamic tsunami waves To describe the initial up to a tsunami wave far from a shore stage of this transformation and to understand mechanism of EM signals arising above the Ocean during seismic activation we formulate a nonlinear mathematical model of seismo-hydro-EM geophysical field interaction in the lithosphere-Ocean-atmosphere medium from the upper mantle under the Ocean up to the ionosphere domain D The model is based on the theory of elasticity electrodynamics fluid dynamics thermodynamics and geophysical data On the basis of this model and its mathematical investigation we calculate generation and propagation of different see above waves in the basin of a model marginal sea the data on the central part of the Sea of Japan were used At the moment t 0 the dynamic interaction process is supposed to be caused by weak may be precursory sub-vertical elastic displacements with the amplitude duration and main frequency of the order of a few cm sec and tenth of Hz respectively at the depth of 37 km under the sea level i e in the upper mantle Other seismic excitations may be considered as well The lithosphere EM signal is generated in the upper mantle conductive </li> <li> <a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70036432','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70036432">Tsunami risk mapping simulation for Malaysia</a> <a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a> Teh, S.Y.; Koh, H. L.; Moh, Y.T.; De Angelis, D. L.; Jiang, J. 2011-01-01 The 26 December 2004 Andaman mega tsunami killed about a quarter of a million people worldwide. Since then several significant tsunamis have recurred in this region, including the most recent 25 October 2010 Mentawai tsunami. These tsunamis grimly remind us of the devastating destruction that a tsunami might inflict on the affected coastal communities. There is evidence that tsunamis of similar or higher magnitudes might occur again in the near future in this region. Of particular concern to Malaysia are tsunamigenic earthquakes occurring along the northern part of the Sunda Trench. Further, the Manila Trench in the South China Sea has been identified as another source of potential tsunamigenic earthquakes that might trigger large tsunamis. To protect coastal communities that might be affected by future tsunamis, an effective early warning system must be properly installed and maintained to provide adequate time for residents to be evacuated from risk zones. Affected communities must be prepared and educated in advance regarding tsunami risk zones, evacuation routes as well as an effective evacuation procedure that must be taken during a tsunami occurrence. For these purposes, tsunami risk zones must be identified and classified according to the levels of risk simulated. This paper presents an analysis of tsunami simulations for the South China Sea and the Andaman Sea for the purpose of developing a tsunami risk zone classification map for Malaysia based upon simulated maximum wave heights. ?? 2011 WIT Press. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016PhDT.......148L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016PhDT.......148L">Acoustic wave propagation and intensity fluctuations in shallow water 2006 experiment</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Luo, Jing Fluctuations of low frequency sound propagation in the presence of nonlinear internal waves during the Shallow Water 2006 experiment are analyzed. Acoustic waves and environmental data including on-board ship radar images were collected simultaneously before, during, and after a strong internal solitary wave packet passed through a source-receiver acoustic track. Analysis of the acoustic wave signals shows temporal intensity fluctuations. These fluctuations are affected by the passing internal wave and agrees well with the theory of the horizontal refraction of acoustic wave propagation in shallow water. The intensity focusing and defocusing that occurs in a fixed source-receiver configuration while internal wave packet approaches and passes the acoustic track is addressed in this thesis. Acoustic ray-mode theory is used to explain the modal evolution of broadband acoustic waves propagating in a shallow water waveguide in the presence of internal waves. Acoustic modal behavior is obtained from the data through modal decomposition algorithms applied to data collected by a vertical line array of hydrophones. Strong interference patterns are observed in the acoustic data, whose main cause is identified as the horizontal refraction referred to as the horizontal Lloyd mirror effect. To analyze this interference pattern, combined Parabolic Equation model and Vertical-mode horizontal-ray model are utilized. A semi-analytic formula for estimating the horizontal Lloyd mirror effect is developed. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010AGUFMOS31D1455D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010AGUFMOS31D1455D">Integrated Historical Tsunami Event and Deposit Database</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Dunbar, P. K.; McCullough, H. L. 2010-12-01 (e.g., earthquake, landslide, volcanic eruption, asteroid impact) is also specified. Observations (grain size, sedimentary structure, bed thickness, number of layers, etc.) are stored along with the conclusions drawn from the evidence by the author (wave height, flow depth, flow velocity, number of waves, etc.). Geologic time periods in the GTD_DB range from Precambrian to Quaternary, but the majority (70%) are from the Quaternary period. This period includes events such as: the 2004 Indian Ocean tsunami, the Cascadia subduction zone earthquakes and tsunamis, the 1755 Lisbon tsunami, the A.D. 79 Vesuvius tsunami, the 3500 BP Santorini caldera collapse and tsunami, and the 7000 BP Storegga landslide-generated tsunami. Prior to the Quaternary period, the majority of the paleotsunamis are due to impact events such as: the Tertiary Chesapeake Bay Bolide, Cretaceous-Tertiary (K/T) Boundary, Cretaceous Manson, and Devonian Alamo. The tsunami deposits are integrated with the historical tsunami event database where applicable. For example, users can search for articles describing deposits related to the 1755 Lisbon tsunami and view those records, as well as link to the related historic event record. The data and information may be viewed using tools designed to extract and display data (selection forms, Web Map Services, and Web Feature Services). </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017RMRE...50.2731Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017RMRE...50.2731Z">Analytical Time-Domain Solution of Plane Wave Propagation Across a Viscoelastic Rock Joint</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Zou, Yang; Li, Jianchun; Laloui, Lyesse; Zhao, Jian 2017-10-01 The effects of viscoelastic filled rock joints on wave propagation are of great significance in rock engineering. The solutions in time domain for plane longitudinal ( P-) and transverse ( S-) waves propagation across a viscoelastic rock joint are derived based on Maxwell and Kelvin models which are, respectively, applied to describe the viscoelastic deformational behaviour of the rock joint and incorporated into the displacement discontinuity model (DDM). The proposed solutions are verified by comparing with the previous studies on harmonic waves, which are simulated by sinusoidal incident P- and S-waves. Comparison between the predicted transmitted waves and the experimental data for P-wave propagation across a joint filled with clay is conducted. The Maxwell is found to be more appropriate to describe the filled joint. The parametric studies show that wave propagation is affected by many factors, such as the stiffness and the viscosity of joints, the incident angle and the duration of incident waves. Furthermore, the dependences of the transmission and reflection coefficients on the specific joint stiffness and viscosity are different for the joints with Maxwell and Kelvin behaviours. The alternation of the reflected and transmitted waveforms is discussed, and the application scope of this study is demonstrated by an illustration of the effects of the joint thickness. The solutions are also extended for multiple parallel joints with the virtual wave source method and the time-domain recursive method. For an incident wave with arbitrary waveform, it is convenient to adopt the present approach to directly calculate wave propagation across a viscoelastic rock joint without additional mathematical methods such as the Fourier and inverse Fourier transforms. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018JPhCS.953a2029L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018JPhCS.953a2029L">Earthquake Early Warning Management based on Client-Server using Primary Wave data from Vibrating Sensor</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Laumal, F. E.; Nope, K. B. N.; Peli, Y. S. 2018-01-01 Early warning is a warning mechanism before an actual incident occurs, can be implemented on natural events such as tsunamis or earthquakes. Earthquakes are classified in tectonic and volcanic types depend on the source and nature. The tremor in the form of energy propagates in all directions as Primary and Secondary waves. Primary wave as initial earthquake vibrations propagates longitudinally, while the secondary wave propagates like as a sinusoidal wave after Primary, destructive and as a real earthquake. To process the primary vibration data captured by the earthquake sensor, a network management required client computer to receives primary data from sensors, authenticate and forward to a server computer to set up an early warning system. With the water propagation concept, a method of early warning system has been determined in which some sensors are located on the same line, sending initial vibrations as primary data on the same scale and the server recommended to the alarm sound as an early warning. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20170009019','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20170009019">Properties, Propagation, and Excitation of EMIC Waves Properties, Propagation, and Excitation of EMIC Waves</a> <a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a> Zhang, Jichun; Coffey, Victoria N.; Chandler, Michael O.; Boardsen, Scott A.; Saikin, Anthony A.; Mello, Emily M.; Russell, Christopher T.; Torbert, Roy B.; Fuselier, Stephen A.; Giles, Barbara L.; <a style="text-decoration: none; " href="javascript:void(0); " onClick="displayelement('author_20170009019'); toggleEditAbsImage('author_20170009019_show'); toggleEditAbsImage('author_20170009019_hide'); "> <img style="display:inline; width:12px; height:12px; " src="images/arrow-up.gif" width="12" height="12" border="0" alt="hide" id="author_20170009019_show"> <img style="width:12px; height:12px; display:none; " src="images/arrow-down.gif" width="12" height="12" border="0" alt="hide" id="author_20170009019_hide"> 2017-01-01 Electromagnetic ion cyclotron (EMIC) waves (0.1-5 Hz) play an important role in particle dynamics in the Earth's magnetosphere. EMIC waves are preferentially excited in regions where hot anisotropic ions and cold dense plasma populations spatially overlap. While the generation region of EMIC waves is usually on or near the magnetic equatorial plane in the inner magnetosphere, EMIC waves have both equatorial and off-equator source regions on the dayside in the compressed outer magnetosphere. Using field and plasma measurements from the Magnetospheric Multiscale (MMS) mission, we perform a case study of EMIC waves and associated local plasma conditions observed on 19 October 2015. From 0315 to 0810 UT, before crossing the magnetopause into the magnetosheath, all four MMS spacecraft detected long-lasting He(exp +)-band EMIC wave emissions around local noon (MLT = 12.7 - 14.0) at high L-shells (L = 8.8 - 15.2) and low magnetic latitudes (MLAT = -21.8deg - -30.3deg). Energetic (greater than 1 keV) and anisotropic ions were present throughout this event that was in the recovery phase of a weak geomagnetic storm (min. Dst = -48 nT at 1000 UT on 18 October 2015). The testing of linear theory suggests that the EMIC waves were excited locally. Although the wave event is dominated by small normal angles, its polarization is mixed with right- and left-handedness and its propagation is bi-directional with regard to the background magnetic field. The short inter-spacecraft distances (as low as 15 km) of the MMS mission make it possible to accurately determine the k vector of the waves using the phase difference technique. Preliminary analysis finds that the k vector magnitude, phase speed, and wavelength of the 0.3-Hz wave packet at 0453:55 UT are 0.005 km(exp -1), 372.9 km/s, and 1242.9 km, respectively. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018PApGe.175.1231R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018PApGe.175.1231R">Introduction to "Global Tsunami Science: Past and Future, Volume III"</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Rabinovich, Alexander B.; Fritz, Hermann M.; Tanioka, Yuichiro; Geist, Eric L. 2018-04-01 Twenty papers on the study of tsunamis are included in Volume III of the PAGEOPH topical issue "Global Tsunami Science: Past and Future". Volume I of this topical issue was published as PAGEOPH, vol. 173, No. 12, 2016 and Volume II as PAGEOPH, vol. 174, No. 8, 2017. Two papers in Volume III focus on specific details of the 2009 Samoa and the 1923 northern Kamchatka tsunamis; they are followed by three papers related to tsunami hazard assessment for three different regions of the world oceans: South Africa, Pacific coast of Mexico and the northwestern part of the Indian Ocean. The next six papers are on various aspects of tsunami hydrodynamics and numerical modelling, including tsunami edge waves, resonant behaviour of compressible water layer during tsunamigenic earthquakes, dispersive properties of seismic and volcanically generated tsunami waves, tsunami runup on a vertical wall and influence of earthquake rupture velocity on maximum tsunami runup. Four papers discuss problems of tsunami warning and real-time forecasting for Central America, the Mediterranean coast of France, the coast of Peru, and some general problems regarding the optimum use of the DART buoy network for effective real-time tsunami warning in the Pacific Ocean. Two papers describe historical and paleotsunami studies in the Russian Far East. The final set of three papers importantly investigates tsunamis generated by non-seismic sources: asteroid airburst and meteorological disturbances. Collectively, this volume highlights contemporary trends in global tsunami research, both fundamental and applied toward hazard assessment and mitigation. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AGUFMNH11C..07B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AGUFMNH11C..07B">The First Real-Time Tsunami Animation</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Becker, N. C.; Wang, D.; McCreery, C.; Weinstein, S.; Ward, B. 2014-12-01 For the first time a U.S. tsunami warning center created and issued a tsunami forecast model animation while the tsunami was still crossing an ocean. Pacific Tsunami Warning Center (PTWC) scientists had predicted they would have this ability (Becker et al., 2012) with their RIFT forecast model (Wang et al., 2009) by using rapidly-determined W-phase centroid-moment tensor earthquake focal mechanisms as tsunami sources in the RIFT model (Wang et al., 2012). PTWC then acquired its own YouTube channel in 2013 for its outreach efforts that showed animations of historic tsunamis (Becker et al., 2013), but could also be a platform for sharing future tsunami animations. The 8.2 Mw earthquake of 1 April 2014 prompted PTWC to issue official warnings for a dangerous tsunami in Chile, Peru and Ecuador. PTWC ended these warnings five hours later, then issued its new tsunami marine hazard product (i.e., no coastal evacuations) for the State of Hawaii. With the international warning canceled but with a domestic hazard still present PTWC generated a forecast model animation and uploaded it to its YouTube channel six hours before the arrival of the first waves in Hawaii. PTWC also gave copies of this animation to television reporters who in turn passed it on to their national broadcast networks. PTWC then created a version for NOAA's Science on a Sphere system so it could be shown on these exhibits as the tsunami was still crossing the Pacific Ocean. While it is difficult to determine how many people saw this animation since local, national, and international news networks showed it in their broadcasts, PTWC's YouTube channel provides some statistics. As of 1 August 2014 this animation has garnered more than 650,000 views. Previous animations, typically released during significant anniversaries, rarely get more than 10,000 views, and even then only when external websites share them. Clearly there is a high demand for a tsunami graphic that shows both the speed and the severity of a </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AGUFMNH21A3834N','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AGUFMNH21A3834N">Comparison between Observed Tsunami Heights and Numerical Simulation of the 1854 Ansei-Tokai Earthquake Tsunami in Gokasho Bay, central Japan</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Naruhashi, R.; Satake, K.; Heidarzadeh, M.; Harada, T. 2014-12-01 　Gokasho Bay is a blockade inner bay which has typical ria coasts and drowned valleys. It is located in the central Kii Peninsula and faces the Nankai Trough subduction zone. This Kumano-nada coastal area has been repeatedly striked by historical great tsunamis. For the 1854 Ansei-Tokai earthquake and its tsunami, there are comparatively many historical records including historical documents and oral traditions for tsunami behavior and damages along the coast.　Based on these records, a total of 42 tsunami heights were measured by using a laser range finder and a hand level on the basis of spot elevation given by 1/2500 topographical maps. The average inundation height of whole bay area was approximately 4 - 5 m. On the whole, in the closed-off section of the bay, large values were obtained. For example, the average value in Gokasho-ura town area was 4 m, and the maximum run-up height along the Gokasho river was 6.8 m. Particularly in Konsa, located in the most closed-off section of the bay, tsunami heights ranged between 4 - 11 m, and were higher than those in other districts. It was comparatively high along the eastern coast and eastern baymouth.　We simulate the distribution of the tsunami wave heights using numerical modeling, and compare the simulation results and above-mentioned actual historical data and results of our field survey. Based on fault models by Ando (1975), Aida (1981), and Annaka et al. (2003), the tsunami simulation was performed.　After comparing the calculated results by three fault models, the wave height based on the model by Annaka et al. (2003) was found to have better agreement with observations. Moreover, the wave height values in a closed-off section of bay and at the eastern baymouth are high consistent with our survey data. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013AGUFMNH51A1605H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013AGUFMNH51A1605H">Tsunami Numerical Simulation for Hypothetical Giant or Great Earthquakes along the Izu-Bonin Trench</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Harada, T.; Ishibashi, K.; Satake, K. 2013-12-01 . Tsunami propagation was computed by the finite-difference method of the non-liner long-wave equations with Corioli's force (Satake, 1995, PAGEOPH) in the area of 130 - 145°E and 25 - 37°N. The 15-seconds gridded bathymetry data are used. The tsunami propagations for eight hours since the faulting of the various fault models were computed. As a result, large tsunamis from assumed giant/great both interplate and outer-rise earthquakes reach the Ryukyu Islands' coasts and the Pacific coasts of Kyushu, Shikoku and western Honshu west of Kanto. Therefore, the tsunami simulations support the Ishibashi and Harada's hypothesis. At the time of writing, the best yet preliminary model to reproduce the 1605 tsunami heights is an outer-rise steep fault model which extends 26.5 - 29.0°N (300 km of length) and with 16.7 m of average slip (Mw 8.6). We will examine tsunami behavior in the Pacific Ocean from this fault model. To examine our results, field investigations of tsunami deposits in the Bonin Islands and discussions on plate dynamics and seismogenic characteristics along the Izu-Bonin trench are necessary. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010EGUGA..12..916W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010EGUGA..12..916W">Numerical modeling of landslide-generated tsunami using adaptive unstructured meshes</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Wilson, Cian; Collins, Gareth; Desousa Costa, Patrick; Piggott, Matthew 2010-05-01 Landslides impacting into or occurring under water generate waves, which can have devastating environmental consequences. Depending on the characteristics of the landslide the waves can have significant amplitude and potentially propagate over large distances. Linear models of classical earthquake-generated tsunamis cannot reproduce the highly nonlinear generation mechanisms required to accurately predict the consequences of landslide-generated tsunamis. Also, laboratory-scale experimental investigation is limited to simple geometries and short time-scales before wave reflections contaminate the data. Computational fluid dynamics models based on the nonlinear Navier-Stokes equations can simulate landslide-tsunami generation at realistic scales. However, traditional chessboard-like structured meshes introduce superfluous resolution and hence the computing power required for such a simulation can be prohibitively high, especially in three dimensions. Unstructured meshes allow the grid spacing to vary rapidly from high resolution in the vicinity of small scale features to much coarser, lower resolution in other areas. Combining this variable resolution with dynamic mesh adaptivity allows such high resolution zones to follow features like the interface between the landslide and the water whilst minimising the computational costs. Unstructured meshes are also better suited to representing complex geometries and bathymetries allowing more realistic domains to be simulated. Modelling multiple materials, like water, air and a landslide, on an unstructured adaptive mesh poses significant numerical challenges. Novel methods of interface preservation must be considered and coupled to a flow model in such a way that ensures conservation of the different materials. Furthermore this conservation property must be maintained during successive stages of mesh optimisation and interpolation. In this paper we validate a new multi-material adaptive unstructured fluid dynamics model </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2003PhDT.......225H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2003PhDT.......225H">Rayleigh wave acoustic emission during crack propagation in steel</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Horne, Michael R. 2003-07-01 An investigation was conducted of the existence of seismic surface pulses (SSP) on crack faces in near-failure fatigue. An SSP has components of various modes of wave propagation. The component with the largest amplitude is a Rayleigh surface wave pulse. The possibility that these surface modes have much higher amplitudes than bulk modes of acoustic emission (AE) was illustrated by an idealized thought experiment relating an SSP on a half-space to the response of crack faces to crack extension. A number of aspects of AE monitoring in finite objects were investigated. Attributes of surface wave propagation on the edge of a specimen were found to be easier to monitor than other modes of wave propagation. Wavelet analysis was used to compare the characteristics of brittle AE with other sources. A new testing paradigm was developed to reduce interference from secondary sources of AE and enhance the investigation of AE from critical crack behavior. Unique specimen design features were developed, data acquisition features sought and validated, a dead weight load frame was modified, and data analysis procedures were developed. Criteria based on velocity, frequency content, amplitude and shape were devised to determine if an AE event is an SSP. The tests were designed to mimic load conditions on structures such as bridges and hence investigate the difference between AE generated in field conditions and that of typical laboratory conditions. Varieties of steel, from very ductile to very brittle, were tested. It was concluded that plastic zone formation, considered a secondary source of AE, was found not to interfere with the SSP activity. The SSP was found experimentally to have 2-3 times the amplitude of the bulk wave AE. The lack of sufficient AE did not allow for determination of conclusive changes in the AE as the specimens approached failure. However, it was found that brittle crack extension in fatigue and ductile failure can produce wave propagation resembling the </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2006PhDT.......156H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2006PhDT.......156H">Rayleigh wave acoustic emission during crack propagation in steel</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Horne, Michael R. An investigation was conducted of the existence of seismic surface pulses (SSP) on crack faces in near-failure fatigue. An SSP has components of various modes of wave propagation. The component with the largest amplitude is a Rayleigh surface wave pulse. The possibility that these surface modes have much higher amplitudes than bulk modes of acoustic emission (AE) was illustrated by an idealized thought experiment relating an SSP on a half-space to the response of crack faces to crack extension. A number of aspects of AE monitoring in finite objects were investigated. Attributes of surface wave propagation on the edge of a specimen were found to be easier to monitor than other modes of wave propagation. Wavelet analysis was used to compare the characteristics of brittle AE with other sources. A new testing paradigm was developed to reduce interference from secondary sources of AE and enhance the investigation of AE from critical crack behavior. Unique specimen design features were developed, data acquisition features sought and validated, a dead weight load frame was modified, and data analysis procedures were developed. Criteria based on velocity, frequency content, amplitude and shape were devised to determine if an AE event is an SSP. The tests were designed to mimic load conditions on structures such as bridges and hence investigate the difference between AE generated in field conditions and that of typical laboratory conditions. Varieties of steel, from very ductile to very brittle, were tested. It was concluded that plastic zone formation, considered a secondary source of AE, was found not to interfere with the SSP activity. The SSP was found experimentally to have 2-3 times the amplitude of the bulk wave AE. The lack of sufficient AE did not allow for determination of conclusive changes in the AE as the specimens approached failure. However, it was found that brittle crack extension in fatigue and ductile failure can produce wave propagation resembling the </li> <li> <a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70024680','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70024680">Complex earthquake rupture and local tsunamis</a> <a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a> Geist, E.L. 2002-01-01 In contrast to far-field tsunami amplitudes that are fairly well predicted by the seismic moment of subduction zone earthquakes, there exists significant variation in the scaling of local tsunami amplitude with respect to seismic moment. From a global catalog of tsunami runup observations this variability is greatest for the most frequently occuring tsunamigenic subduction zone earthquakes in the magnitude range of 7 < Mw < 8.5. Variability in local tsunami runup scaling can be ascribed to tsunami source parameters that are independent of seismic moment: variations in the water depth in the source region, the combination of higher slip and lower shear modulus at shallow depth, and rupture complexity in the form of heterogeneous slip distribution patterns. The focus of this study is on the effect that rupture complexity has on the local tsunami wave field. A wide range of slip distribution patterns are generated using a stochastic, self-affine source model that is consistent with the falloff of far-field seismic displacement spectra at high frequencies. The synthetic slip distributions generated by the stochastic source model are discretized and the vertical displacement fields from point source elastic dislocation expressions are superimposed to compute the coseismic vertical displacement field. For shallow subduction zone earthquakes it is demonstrated that self-affine irregularities of the slip distribution result in significant variations in local tsunami amplitude. The effects of rupture complexity are less pronounced for earthquakes at greater depth or along faults with steep dip angles. For a test region along the Pacific coast of central Mexico, peak nearshore tsunami amplitude is calculated for a large number (N = 100) of synthetic slip distribution patterns, all with identical seismic moment (Mw = 8.1). Analysis of the results indicates that for earthquakes of a fixed location, geometry, and seismic moment, peak nearshore tsunami amplitude can vary by a </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li class="active">25</li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> </div> <div class="footer-extlink text-muted" style="margin-bottom:1rem; text-align:center;">Some links on this page may take you to non-federal websites. 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Sample records for tsunami wave propagation