Ensemble Simulation of the Atmospheric Radionuclides Discharged by the Fukushima Nuclear Accident

NASA Astrophysics Data System (ADS)

Sekiyama, Thomas; Kajino, Mizuo; Kunii, Masaru

2013-04-01

Enormous amounts of radionuclides were discharged into the atmosphere by a nuclear accident at the Fukushima Daiichi nuclear power plant (FDNPP) after the earthquake and tsunami on 11 March 2011. The radionuclides were dispersed from the power plant and deposited mainly over eastern Japan and the North Pacific Ocean. A lot of numerical simulations of the radionuclide dispersion and deposition had been attempted repeatedly since the nuclear accident. However, none of them were able to perfectly simulate the distribution of dose rates observed after the accident over eastern Japan. This was partly due to the error of the wind vectors and precipitations used in the numerical simulations; unfortunately, their deterministic simulations could not deal with the probability distribution of the simulation results and errors. Therefore, an ensemble simulation of the atmospheric radionuclides was performed using the ensemble Kalman filter (EnKF) data assimilation system coupled with the Japan Meteorological Agency (JMA) non-hydrostatic mesoscale model (NHM); this mesoscale model has been used operationally for daily weather forecasts by JMA. Meteorological observations were provided to the EnKF data assimilation system from the JMA operational-weather-forecast dataset. Through this ensemble data assimilation, twenty members of the meteorological analysis over eastern Japan from 11 to 31 March 2011 were successfully obtained. Using these meteorological ensemble analysis members, the radionuclide behavior in the atmosphere such as advection, convection, diffusion, dry deposition, and wet deposition was simulated. This ensemble simulation provided the multiple results of the radionuclide dispersion and distribution. Because a large ensemble deviation indicates the low accuracy of the numerical simulation, the probabilistic information is obtainable from the ensemble simulation results. For example, the uncertainty of precipitation triggered the uncertainty of wet deposition; the uncertainty of wet deposition triggered the uncertainty of atmospheric radionuclide amounts. Then the remained radionuclides were transported downwind; consequently the uncertainty signal of the radionuclide amounts was propagated downwind. The signal propagation was seen in the ensemble simulation by the tracking of the large deviation areas of radionuclide concentration and deposition. These statistics are able to provide information useful for the probabilistic prediction of radionuclides.

Japan Meteorological Agency/Meteorological Research Institute-Coupled Prediction System version 1 (JMA/MRI-CPS1) for operational seasonal forecasting

NASA Astrophysics Data System (ADS)

Takaya, Yuhei; Yasuda, Tamaki; Fujii, Yosuke; Matsumoto, Satoshi; Soga, Taizo; Mori, Hirotoshi; Hirai, Masayuki; Ishikawa, Ichiro; Sato, Hitoshi; Shimpo, Akihiko; Kamachi, Masafumi; Ose, Tomoaki

2017-01-01

This paper describes the operational seasonal prediction system of the Japan Meteorological Agency (JMA), the Japan Meteorological Agency/Meteorological Research Institute-Coupled Prediction System version 1 (JMA/MRI-CPS1), which was in operation at JMA during the period between February 2010 and May 2015. The predictive skill of the system was assessed with a set of retrospective seasonal predictions (reforecasts) covering 30 years (1981-2010). JMA/MRI-CPS1 showed reasonable predictive skill for the El Niño-Southern Oscillation, comparable to the skills of other state-of-the-art systems. The one-tiered approach adopted in JMA/MRI-CPS1 improved its overall predictive skills for atmospheric predictions over those of the two-tiered approach of the previous uncoupled system. For 3-month predictions with a 1-month lead, JMA/MRI-CPS1 showed statistically significant skills in predicting 500-hPa geopotential height and 2-m temperature in East Asia in most seasons; thus, it is capable of providing skillful seasonal predictions for that region. Furthermore, JMA/MRI-CPS1 was superior overall to the previous system for atmospheric predictions with longer (4-month) lead times. In particular, JMA/MRI-CPS1 was much better able to predict the Asian Summer Monsoon than the previous two-tiered system. This enhanced performance was attributed to the system's ability to represent atmosphere-ocean coupled variability over the Indian Ocean and the western North Pacific from boreal winter to summer following winter El Niño events, which in turn influences the East Asian summer climate through the Pacific-Japan teleconnection pattern. These substantial improvements obtained by using an atmosphere-ocean coupled general circulation model underpin its success in providing more skillful seasonal forecasts on an operational basis.

Real-time forecasting of the April 11, 2012 Sumatra tsunami

USGS Publications Warehouse

Wang, Dailin; Becker, Nathan C.; Walsh, David; Fryer, Gerard J.; Weinstein, Stuart A.; McCreery, Charles S.; ,

2012-01-01

The April 11, 2012, magnitude 8.6 earthquake off the northern coast of Sumatra generated a tsunami that was recorded at sea-level stations as far as 4800 km from the epicenter and at four ocean bottom pressure sensors (DARTs) in the Indian Ocean. The governments of India, Indonesia, Sri Lanka, Thailand, and Maldives issued tsunami warnings for their coastlines. The United States' Pacific Tsunami Warning Center (PTWC) issued an Indian Ocean-wide Tsunami Watch Bulletin in its role as an Interim Service Provider for the region. Using an experimental real-time tsunami forecast model (RIFT), PTWC produced a series of tsunami forecasts during the event that were based on rapidly derived earthquake parameters, including initial location and Mwp magnitude estimates and the W-phase centroid moment tensor solutions (W-phase CMTs) obtained at PTWC and at the U. S. Geological Survey (USGS). We discuss the real-time forecast methodology and how successive, real-time tsunami forecasts using the latest W-phase CMT solutions improved the accuracy of the forecast.

Public-policy issues associated with the SAFRR Tsunami Scenario: Chapter M in The SAFRR (Science Application for Risk Reduction) Tsunami Scenario

USGS Publications Warehouse

Johnson, Laurie; Real, Chuck

2013-01-01

The SAFRR (Science Application for Risk Reduction) tsunami scenario simulates a tsunami generated by a hypothetical magnitude 9.1 earthquake that occurs offshore of the Alaska Peninsula (Kirby and others, 2013). In addition to the work performed by the authors on public-policy issues associated with the SAFRR tsunami scenario, this section of the scenario also reflects the policy discussions of the State of California’s Tsunami Policy Work Group, a voluntary advisory body formed in October 2011, which operates under the California Natural Resources Agency (CNRA), Department of Conservation, and is charged with identifying, evaluating, and making recommendations to resolve issues that are preventing full and effective implementation of tsunami hazard mitigation and risk reduction throughout California’s coastal communities. It also presents the analyses of plans and hazard policies of California’s coastal counties, incorporated cities, and major ports performed by the staff of the California Geological Survey (CGS) and Lauren Prehoda, Office of Environmental and Government Affairs, California Department of Conservation. It also draws on the policy framework and assessment prepared for the ARkStorm Pacific Coast winter storm and catastrophic flooding (Topping and others, 2010).

Interactions of the EGFR juxtamembrane domain with PIP2-containing lipid bilayers: Insights from multiscale molecular dynamics simulations☆

PubMed Central

Abd Halim, Khairul Bariyyah; Koldsø, Heidi; Sansom, Mark S.P.

2015-01-01

Background The epidermal growth factor receptor (EGFR) is the best characterised member of the receptor tyrosine kinases, which play an important role in signalling across mammalian cell membranes. The EGFR juxtamembrane (JM) domain is involved in the mechanism of activation of the receptor, interacting with the anionic lipid phosphatidylinositol 4,5-bisphosphate (PIP2) in the intracellular leaflet of the cell membrane. Methods Multiscale MD simulations were used to characterize PIP2–JM interactions. Simulations of the transmembrane helix plus JM region (TM–JM) dimer (PDB:2M20) in both PIP2-containing and PIP2-depleted lipid bilayer membranes revealed the interactions of the JM with PIP2 and other lipids. Results PIP2 forms strong interactions with the basic residues in the R645–R647 motif of the JM domain resulting in clustering of PIP2 around the protein. This association of PIP2 and the JM domain aids stabilization of JM-A dimer away from the membrane. Mutation (R645N/R646N/R647N) or PIP2-depletion results in deformation of the JM-A dimer and changes in JM–membrane interactions. Conclusions These simulations support the proposal that the positively charged residues at the start of the JM-A domain stabilize the JM-A helices in an orientation away from the membrane surface through binding to PIP2, thus promoting a conformation corresponding to an asymmetric (i.e. activated) kinase. General significance This study indicates that MD simulations may be used to characterise JM/lipid interactions, thus helping to define their role in the mechanisms of receptor tyrosine kinases. This article is part of a Special Issue entitled Recent developments of molecular dynamics. PMID:25219456

Interactions of the EGFR juxtamembrane domain with PIP2-containing lipid bilayers: Insights from multiscale molecular dynamics simulations.

PubMed

Abd Halim, Khairul Bariyyah; Koldsø, Heidi; Sansom, Mark S P

2015-05-01

The epidermal growth factor receptor (EGFR) is the best characterised member of the receptor tyrosine kinases, which play an important role in signalling across mammalian cell membranes. The EGFR juxtamembrane (JM) domain is involved in the mechanism of activation of the receptor, interacting with the anionic lipid phosphatidylinositol 4,5-bisphosphate (PIP2) in the intracellular leaflet of the cell membrane. Multiscale MD simulations were used to characterize PIP2-JM interactions. Simulations of the transmembrane helix plus JM region (TM-JM) dimer (PDB:2M20) in both PIP2-containing and PIP2-depleted lipid bilayer membranes revealed the interactions of the JM with PIP2 and other lipids. PIP2 forms strong interactions with the basic residues in the R645-R647 motif of the JM domain resulting in clustering of PIP2 around the protein. This association of PIP2 and the JM domain aids stabilization of JM-A dimer away from the membrane. Mutation (R645N/R646N/R647N) or PIP2-depletion results in deformation of the JM-A dimer and changes in JM-membrane interactions. These simulations support the proposal that the positively charged residues at the start of the JM-A domain stabilize the JM-A helices in an orientation away from the membrane surface through binding to PIP2, thus promoting a conformation corresponding to an asymmetric (i.e. activated) kinase. This study indicates that MD simulations may be used to characterise JM/lipid interactions, thus helping to define their role in the mechanisms of receptor tyrosine kinases. This article is part of a Special Issue entitled Recent developments of molecular dynamics. Copyright © 2014. Published by Elsevier B.V.

Introduction to "Global Tsunami Science: Past and Future, Volume III"

NASA Astrophysics Data System (ADS)

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.

Introduction to “Global tsunami science: Past and future, Volume III”

USGS Publications Warehouse

Rabinovich, Alexander B.; Fritz, Hermann M.; Tanioka, Yuichiro; Geist, Eric L.

2018-01-01

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.

Correction to "Influence of Dust and Black Carbon on the Snow Albedo in the NASA Goddard Earth Observing System Version 5 Land Surface Model"

NASA Technical Reports Server (NTRS)

Yasunari, Teppei J.; Koster, Randal D.; Kau, K. M.; Aoki, Teruo; Sud, Yogesh C.; Yamazaki, Takeshi; Motoyoshi, Hiroki; Kokdama, Yuji

2012-01-01

The website information describing the forcing meteorological data used for the land surface model (LSM) simulation, which were observed at an Automated Meteorological Station CAWS) at the Sapporo District Meteorological Observatory maintained by the Japan Meteorological Agency (JMA), was missing from the text. The 1-hourly data were obtained from the website of Kisyoutoukeijouhou (Information for available JMA-observed meteorological data in the past) on the website of JMA (in Japanese) (available at: http://www.jma.go.jpijmaimenulreport.html). The measurement height information of 59.5 m for the anemometer at the Sapporo Observatory was also obtained from the website of JMA (in Japanese) (available at: http://www.jma.go.jp/jma/menu/report.html). In addition, the converted 10-m wind speed, based on the AWS/JMA data, was further converted to a 2-m wind speed prior to its use with the land model as a usual treatment of off-line Catchment simulation. Please ignore the ice absorption data on the website mentioned in paragraph [15] which was not used for our calculations (but the data on the website was mostly the same as the estimated ice absorption coefficients by the following method because they partially used the same data by Warren [1984]). We calculated the ice absorption coefficients with the method mentioned in the same paragraph, for which some of the refractive index data by Warren [1984] were used and then interpolated between wavelengths, and also mentioned in paragraph [20] for the visible (VIS) and near-infrared (NIR) ranges. The optical data we used were interpolated between wavelengths as necessary.

33 CFR 165.14-1414 - Safety Zones; Hawaiian Islands Commercial Harbors; HI.

Code of Federal Regulations, 2014 CFR

2014-07-01

... harbors, or all of these harbors, dependent upon details in the tsunami warning. These safety zones extend... period. Paragraph (b) of this section will be enforced when a tsunami warning has been issued for the... Coast Guard's Homeport Web site. Following the passage of the tsunami or tsunami threat and harbor...

Performance of Real-time Earthquake Information System in Japan

NASA Astrophysics Data System (ADS)

Nakamura, H.; Horiuchi, S.; Wu, C.; Yamamoto, S.

2008-12-01

Horiuchi et al. (2005) developed a real-time earthquake information system (REIS) using Hi-net, a densely deployed nationwide seismic network, which consists of about 800 stations operated by NIED, Japan. REIS determines hypocenter locations and earthquake magnitudes automatically within a few seconds after P waves arrive at the closest station and calculates focal mechanisms within about 15 seconds. Obtained hypocenter parameters are transferred immediately by using XML format to a computer in Japan Meteorological Agency (JMA), who started the service of EEW to special users in June 2005. JMA also developed EEW using 200 stations. The results by the two systems are merged. Among all the first issued EEW reports by both systems, REIS information accounts for about 80 percent. This study examines the rapidity and credibility of REIS by analyzing the 4050 earthquakes which occurred around the Japan Islands since 2005 with magnitude larger than 3.0. REIS re-determines hypocenter parameters every one second according to the revision of waveform data. Here, we discuss only about the results by the first reports. On rapidness, our results show that about 44 percent of the first reports are issued within 5 seconds after the P waves arrives at the closest stations. Note that this 5-second time window includes time delay due to data package and transmission delay of about 2 seconds. REIS waits till two stations detect P waves for events in the network but four stations outside the network so as to get reliable solutions. For earthquakes with hypocentral distance less than 100km, 55 percent of earthquakes are warned in 5 seconds and 87 percent are warned in 10 seconds. Most of events having long time delay are small and triggered by S wave arrivals. About 80 percent of events have difference in epicenter distances less than 20km relative to JMA manually determined locations. Because of the existence of large lateral heterogeneity in seismic velocity, the difference depends on regions and tends to increase when earthquakes occurred outward the network. Depth differences for 70 percent of events are less than 20km and original time differences for 48 percent within one second. In addition to JMA magnitude (MJMA), which is estimated from moment magnitude, REIS estimates a new scaling parameter called intensity magnitude (MI), which is defined from observed P wave seismic intensity (Yamamoto et al., 2008). Our statistical results show that these two kinds of magnitudes are reasonably determined. Either MJMA or MI by REIS for 94 percent of events has differences less than 1.0 compared with reported JMA catalog. However, the difference increases with values of the magnitude. There is an apparent underestimation of MJMA for large earthquakes because the first report is issued when the rupture is still undergoing. Moreover, there are cases when most of Hi-net seismograms close to epicenter are clipped, but still these data are used for the determination of the lower limit of magnitude. We are making an EEWS using real-time strong motion network data for the better estimate of earthquake magnitude and seismic intensity.

New Tsunami Response, Mitigation, and Recovery Planning "Playbooks" for California (USA) Maritime Communities

NASA Astrophysics Data System (ADS)

Wilson, R. I.; Lynett, P. J.; Miller, K.; Eskijian, M.; Dengler, L. A.; Ayca, A.; Keen, A.; Admire, A. R.; Siegel, J.; Johnson, L. A.; Curtis, E.; Hornick, M.

2015-12-01

The 2010 Chile and 2011 Japan tsunamis both struck the California coast offering valuable experience and raised a number of significant issues for harbor masters, port captains, and other maritime entities. There was a general call for more planning products to help guide maritime communities in their tsunami response, mitigation, and recovery activities. The State of California is working with the U.S. Federal Emergency Management Agency (FEMA), the U.S. National Tsunami Hazard Mitigation Program (NTHMP), and other tsunami experts to provide communities with new tsunami planning tools to address these issues: Response Playbooks and plans have been developed for ports and harbors identifying potential tsunami current hazards and related damage for various size events. Maps have been generated showing minor, moderate, and severe damage levels that have been linked to current velocity thresholds of 3, 6, and 9 knots, respectively. Knowing this information allows harbor personnel to move ships or strengthen infrastructure prior to the arrival of distant source tsunamis. Damage probability tools and mitigation plans have been created to help reduce tsunami damage by evaluating the survivability of small and large vessels in harbors and ports. These results were compared to the actual damage assessments performed in California and Japan following the 2011 Japanese tsunami. Fragility curves were developed based on current velocity and direction to help harbor and port officials upgrade docks, piles, and related structures. Guidance documents are being generated to help in the development of both local and statewide recovery plans. Additional tools, like post-tsunami sediment and debris movement models, will allow harbors and ports to better understand if and where recovery issues are most likely to occur. Streamlining the regulatory and environmental review process is also a goal of the guidance. These maritime products and procedures are being integrated into guidance through the NTHMP to help other U.S. states/territories/commonwealths develop their own tsunami planning tools. This will lead to more accurate, consistent, and cost-effective tsunami planning strategies within the U.S.

Introduction to “Global tsunami science: Past and future, Volume I”

USGS Publications Warehouse

Geist, Eric L.; Fritz, Hermann; Rabinovich, Alexander B.; Tanioka, Yuichiro

2016-01-01

Twenty-five papers on the study of tsunamis are included in Volume I of the PAGEOPH topical issue “Global Tsunami Science: Past and Future”. Six papers examine various aspects of tsunami probability and uncertainty analysis related to hazard assessment. Three papers relate to deterministic hazard and risk assessment. Five more papers present new methods for tsunami warning and detection. Six papers describe new methods for modeling tsunami hydrodynamics. Two papers investigate tsunamis generated by non-seismic sources: landslides and meteorological disturbances. The final three papers describe important case studies of recent and historical events. Collectively, this volume highlights contemporary trends in global tsunami research, both fundamental and applied toward hazard assessment and mitigation.

Introduction to "Global Tsunami Science: Past and Future, Volume I"

NASA Astrophysics Data System (ADS)

Geist, Eric L.; Fritz, Hermann M.; Rabinovich, Alexander B.; Tanioka, Yuichiro

2016-12-01

Twenty-five papers on the study of tsunamis are included in Volume I of the PAGEOPH topical issue "Global Tsunami Science: Past and Future". Six papers examine various aspects of tsunami probability and uncertainty analysis related to hazard assessment. Three papers relate to deterministic hazard and risk assessment. Five more papers present new methods for tsunami warning and detection. Six papers describe new methods for modeling tsunami hydrodynamics. Two papers investigate tsunamis generated by non-seismic sources: landslides and meteorological disturbances. The final three papers describe important case studies of recent and historical events. Collectively, this volume highlights contemporary trends in global tsunami research, both fundamental and applied toward hazard assessment and mitigation.

Real time assessment of the 15 July 2009 New Zealand tsunami

NASA Astrophysics Data System (ADS)

Uslu, Burak; Power, William; Greensdale, Dianne; Titov, Vasily

2010-05-01

On the 15th July 2009 a Mw 7.6 earthquake occurred off the coast of Fiordland in the South Island of New Zealand, about 1200 km from Auckland, New Zealand, 1500 km from Hobart, Tasmania and 1800 km from Sydney, Australia. A tsunami was generated and an initial warning issued by the PTWC. The Centre for Australian Weather and Climate issued its first tsunami warning for coastal regions of eastern Australia and New Zealand 24 minutes after the earthquake. By serendipitous coincidence, the earthquake struck while the International Tsunami Symposium was in session in Novosibirsk Russia. This provided the opportunity to test, in real-time, several tsunami warning systems in front of attending scientists (Schiermeier, 2009). NOAA Center for Tsunami Research, Pacific Tsunami Warning Center, GNS Science, and Centre for Australian Weather and Climate scientists were present at the symposium and worked together. Vasily Titov showed "live" NOAA's methodology (Bernard et al, 2006) to assess the tsunami potential and, in consultation with colleagues, provided warning guidance, and the warning was eventually canceled. We discuss how the forecast was done and how accurate the initial determination was. References Bernard E.N. et al., 2006, Tsunami: scientific frontiers, mitigation, forecasting and policy implications, Phil. Trans. R. Soc. A, 364:1989-2007; doi:10.1098/rsta.2006.1809 Schiermeier, Q., 2009, Tsunami forecast in real time, Published online 16 July 2009 | Nature | doi:10.1038/news.2009.702

U.S. Tsunami Information technology (TIM) Modernization: Performance Assessment of Tsunamigenic Earthquake Discrimination System

NASA Astrophysics Data System (ADS)

Hagerty, M. T.; Lomax, A.; Hellman, S. B.; Whitmore, P.; Weinstein, S.; Hirshorn, B. F.; Knight, W. R.

2015-12-01

Tsunami warning centers must rapidly decide whether an earthquake is likely to generate a destructive tsunami in order to issue a tsunami warning quickly after a large event. For very large events (Mw > 8 or so), magnitude and location alone are sufficient to warrant an alert. However, for events of smaller magnitude (e.g., Mw ~ 7.5), particularly for so-called "tsunami earthquakes", magnitude alone is insufficient to issue an alert and other measurements must be rapidly made and used to assess tsunamigenic potential. The Tsunami Information technology Modernization (TIM) is a National Oceanic and Atmospheric Administration (NOAA) project to update and standardize the earthquake and tsunami monitoring systems currently employed at the U.S. Tsunami Warning Centers in Ewa Beach, Hawaii (PTWC) and Palmer, Alaska (NTWC). We (ISTI) are responsible for implementing the seismic monitoring components in this new system, including real-time seismic data collection and seismic processing. The seismic data processor includes a variety of methods aimed at real-time discrimination of tsunamigenic events, including: Mwp, Me, slowness (Theta), W-phase, mantle magnitude (Mm), array processing and finite-fault inversion. In addition, it contains the ability to designate earthquake scenarios and play the resulting synthetic seismograms through the processing system. Thus, it is also a convenient tool that integrates research and monitoring and may be used to calibrate and tune the real-time monitoring system. Here we show results of the automated processing system for a large dataset of subduction zone earthquakes containing recent tsunami earthquakes and we examine the accuracy of the various discrimation methods and discuss issues related to their successful real-time application.

SAFRR Tsunami Scenarios and USGS-NTHMP Collaboration

NASA Astrophysics Data System (ADS)

Ross, S.; Wood, N. J.; Cox, D. A.; Jones, L.; Cheung, K. F.; Chock, G.; Gately, K.; Jones, J. L.; Lynett, P. J.; Miller, K.; Nicolsky, D.; Richards, K.; Wein, A. M.; Wilson, R. I.

2015-12-01

Hazard scenarios provide emergency managers and others with information to help them prepare for future disasters. The SAFRR Tsunami Scenario, published in 2013, modeled a hypothetical but plausible tsunami, created by an Mw9.1 earthquake occurring offshore from the Alaskan peninsula, and its impacts on the California coast. It presented the modeled inundation areas, current velocities in key ports and harbors, physical damage and repair costs, economic consequences, environmental impacts, social vulnerability, emergency management, and policy implications for California associated with the scenario tsunami. The intended users were those responsible for making mitigation decisions before and those who need to make rapid decisions during future tsunamis. It provided the basis for many exercises involving, among others, NOAA, the State of Washington, several counties in California, and the National Institutes of Health. The scenario led to improvements in the warning protocol for southern California and highlighted issues that led to ongoing work on harbor and marina safety. Building on the lessons learned in the SAFRR Tsunami Scenario, another tsunami scenario is being developed with impacts to Hawaii and to the source region in Alaska, focusing on the evacuation issues of remote communities with primarily shore parallel roads, and also on the effects of port closures. Community exposure studies in Hawaii (Ratliff et al., USGS-SIR, 2015) provided background for selecting these foci. One complicated and important aspect of any hazard scenario is defining the source event. The USGS is building collaborations with the National Tsunami Hazard Mitigation Program (NTHMP) to consider issues involved in developing a standardized set of tsunami sources to support hazard mitigation work. Other key USGS-NTHMP collaborations involve population vulnerability and evacuation modeling.

The First Real-Time Tsunami Animation

NASA Astrophysics Data System (ADS)

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 tsunami before it reaches impacted coastlines, similar to how radar and satellite images show the advancement of storms. Though this animation showed that most of the tsunami waves would not be dangerous, future publication of these animations will require additional outreach and education to avoid any unnecessary alarm. https://www.youtube.com/user/PacificTWC

Tsunami Warning Protocol for Eruptions of Augustine Volcano, Cook Inlet, Alaska

NASA Astrophysics Data System (ADS)

Whitmore, P.; Neal, C.; Nyland, D.; Murray, T.; Power, J.

2006-12-01

Augustine is an island volcano that has generated at least one tsunami. During its January 2006 eruption coastal residents of lower Cook Inlet became concerned about tsunami potential. To address this concern, NOAA's West Coast/ Alaska Tsunami Warning Center (WC/ATWC) and the Alaska Volcano Observatory (AVO) jointly developed a tsunami warning protocol for the most likely scenario for tsunami generation at Augustine: a debris avalanche into the Cook Inlet. Tsunami modeling indicates that a wave generated at Augustine volcano could reach coastal communities in approximately 55 minutes. If a shallow seismic event with magnitude greater than 4.5 occurred near Augustine and the AVO had set the level of concern color code to orange or red, the WC/ATWC would immediately issue a warning for the lower Cook Inlet. Given the short tsunami travel times involved, potentially affected communities would be provided as much lead time as possible. Large debris avalanches that could trigger a tsunami in lower Cook Inlet are expected to be accompanied by a strong seismic signal. Seismograms produced by these debris avalanches have unique spectral characteristics. After issuing a warning, the WC/ATWC would compare the observed waveform with known debris avalanches, and would consult with AVO to further evaluate the event using AVO's on-island networks (web cameras, seismic network, etc) to refine or cancel the warning. After the 2006 eruptive phase ended, WC/ATWC, with support from AVO and the University of Alaska Tsunami Warning and Environmental Observatory for Alaska program (TWEAK), developed and installed "splash-gauges" which will provide confirmation of tsunami generation.

S-net : Construction of large scale seafloor observatory network for tsunamis and earthquakes along the Japan Trench

NASA Astrophysics Data System (ADS)

Mochizuki, M.; Uehira, K.; Kanazawa, T.; Shiomi, K.; Kunugi, T.; Aoi, S.; Matsumoto, T.; Sekiguchi, S.; Yamamoto, N.; Takahashi, N.; Nakamura, T.; Shinohara, M.; Yamada, T.

2017-12-01

NIED has launched the project of constructing a seafloor observatory network for tsunamis and earthquakes after the occurrence of the 2011 Tohoku Earthquake to enhance reliability of early warnings of tsunamis and earthquakes. The observatory network was named "S-net". The S-net project has been financially supported by MEXT.The S-net consists of 150 seafloor observatories which are connected in line with submarine optical cables. The total length of submarine optical cable is about 5,500 km. The S-net covers the focal region of the 2011 Tohoku Earthquake and its vicinity regions. Each observatory equips two units of a high sensitive pressure gauges as a tsunami meter and four sets of three-component seismometers. The S-net is composed of six segment networks. Five of six segment networks had been already installed. Installation of the last segment network covering the outer rise area have been finally finished by the end of FY2016. The outer rise segment has special features like no other five segments of the S-net. Those features are deep water and long distance. Most of 25 observatories on the outer rise segment are located at the depth of deeper than 6,000m WD. Especially, three observatories are set on the seafloor of deeper than about 7.000m WD, and then the pressure gauges capable of being used even at 8,000m WD are equipped on those three observatories. Total length of the submarine cables of the outer rise segment is about two times longer than those of the other segments. The longer the cable system is, the higher voltage supply is needed, and thus the observatories on the outer rise segment have high withstanding voltage characteristics. We employ a dispersion management line of a low loss formed by combining a plurality of optical fibers for the outer rise segment cable, in order to achieve long-distance, high-speed and large-capacity data transmission Installation of the outer rise segment was finished and then full-scale operation of S-net has started. All the data from 150 seafloor observatories are being transferred to and stored in the Tsukuba DC. Some data are being transmitted directly to JMA and have been used for monitoring of earthquakes and tsunamis. We will report construction and operation of the S-net system as well as the outline of the obtained data in this presentation.

Improving tsunami resiliency: California's Tsunami Policy Working Group

USGS Publications Warehouse

Real, Charles R.; Johnson, Laurie; Jones, Lucile M.; Ross, Stephanie L.; Kontar, Y.A.; Santiago-Fandiño, V.; Takahashi, T.

2014-01-01

California has established a Tsunami Policy Working Group to facilitate development of policy recommendations for tsunami hazard mitigation. The Tsunami Policy Working Group brings together government and industry specialists from diverse fields including tsunami, seismic, and flood hazards, local and regional planning, structural engineering, natural hazard policy, and coastal engineering. The group is acting on findings from two parallel efforts: The USGS SAFRR Tsunami Scenario project, a comprehensive impact analysis of a large credible tsunami originating from an M 9.1 earthquake in the Aleutian Islands Subduction Zone striking California’s coastline, and the State’s Tsunami Preparedness and Hazard Mitigation Program. The unique dual-track approach provides a comprehensive assessment of vulnerability and risk within which the policy group can identify gaps and issues in current tsunami hazard mitigation and risk reduction, make recommendations that will help eliminate these impediments, and provide advice that will assist development and implementation of effective tsunami hazard risk communication products to improve community resiliency.

Introduction to "Tsunami Science: Ten Years After the 2004 Indian Ocean Tsunami. Volume I"

NASA Astrophysics Data System (ADS)

Rabinovich, Alexander B.; Geist, Eric L.; Fritz, Hermann M.; Borrero, Jose C.

2015-03-01

Twenty-two papers on the study of tsunamis are included in Volume I of the PAGEOPH topical issue "Tsunami Science: Ten Years after the 2004 Indian Ocean Tsunami." Eight papers examine various aspects of past events with an emphasis on case and regional studies. Five papers are on tsunami warning and forecast, including the improvement of existing tsunami warning systems and the development of new warning systems in the northeast Atlantic and Mediterranean region. Three more papers present the results of analytical studies and discuss benchmark problems. Four papers report the impacts of tsunamis, including the detailed calculation of inundation onshore and into rivers and probabilistic analysis for engineering purposes. The final two papers relate to important investigations of the source and tsunami generation. Overall, the volume not only addresses the pivotal 2004 Indian Ocean (Sumatra) and 2011 Japan (Tohoku) tsunamis, but also examines the tsunami hazard posed to other critical coasts in the world.

Tsunami hazard mitigation in tourism in the tropical and subtropical coastal areas: a case study in the Ryukyu Islands, southwest of Japan

NASA Astrophysics Data System (ADS)

Matsumoto, T.

2006-12-01

Life and economy (including tourism) in tropical and subtropical coastal areas, such as Okinawa Prefecture (Ryukyu) are highly relying on the sea. The sea has both "gentle" side to give people healing and "dangerous" side to kill people. If we are going to utilise the sea for marine tourism such as constructing resort facilities on the oceanfront, we should know all of the sea, including the both sides of the sea: especially the nature of tsunamis. And also we islanders should issue accurate information about the sea towards outsiders, especially tourists visiting the island. We have already learned a lesson about this issue from the Sumatra tsunami in 2004. However, measures against the tsunami disaster by marine tourism industry are still inadequate in these areas. The goal of tsunami hazard mitigation for those engaged in tourism industry in tropical and subtropical coastal areas should be as follows. (1) Preparedness against tsunamis: "Be aware of the characteristics of tsunamis." "Prepare tsunamis when you feel an earthquake." "Prepare tsunamis when an earthquake takes place somewhere in the world." (2) Maintenance of an exact tsunami hazard map under quantitative analyses of the characteristics of tsunamis: "Flooding areas by tsunami attacks are dependent not only on altitude but also on amplification and inundation due to the seafloor topography near the coast and the onland topographic relief." "Tsunami damage happens repeatedly." (3) Maintenance of a tsunami disaster prevention manual and training after the manual: "Who should do what in case of tsunamis?" "How should the resort hotel employees lead the guests to the safe place?" Such a policy for disaster prevention is discussed in the class of the general education of "Ocean Sciences" in University of the Ryukyus (UR) and summer school for high school students. The students (most of them are from Okinawa Prefecture) consider, discuss and make reports about what to do in case of tsunamis as an islander. Especially, students of Department of Tourism Sciences (DTS) are keen on the discussion and make excellent reports/proposals. Here, the author would also like to introduce some of them in the presentation.

Japan Meteorological Agency/Meteorological Research Institute-Coupled Prediction System version 2 (JMA/MRI-CPS2): atmosphere-land-ocean-sea ice coupled prediction system for operational seasonal forecasting

NASA Astrophysics Data System (ADS)

Takaya, Yuhei; Hirahara, Shoji; Yasuda, Tamaki; Matsueda, Satoko; Toyoda, Takahiro; Fujii, Yosuke; Sugimoto, Hiroyuki; Matsukawa, Chihiro; Ishikawa, Ichiro; Mori, Hirotoshi; Nagasawa, Ryoji; Kubo, Yutaro; Adachi, Noriyuki; Yamanaka, Goro; Kuragano, Tsurane; Shimpo, Akihiko; Maeda, Shuhei; Ose, Tomoaki

2018-02-01

This paper describes the Japan Meteorological Agency/Meteorological Research Institute-Coupled Prediction System version 2 (JMA/MRI-CPS2), which was put into operation in June 2015 for the purpose of performing seasonal predictions. JMA/MRI-CPS2 has various upgrades from its predecessor, JMA/MRI-CPS1, including improved resolution and physics in its atmospheric and oceanic components, introduction of an interactive sea-ice model and realistic initialization of its land component. Verification of extensive re-forecasts covering a 30-year period (1981-2010) demonstrates that JMA/MRI-CPS2 possesses improved seasonal predictive skills for both atmospheric and oceanic interannual variability as well as key coupled variability such as the El Niño-Southern Oscillation (ENSO). For ENSO prediction, the new system better represents the forecast uncertainty and transition/duration of ENSO phases. Our analysis suggests that the enhanced predictive skills are attributable to incremental improvements resulting from all of the changes, as is apparent in the beneficial effects of sea-ice coupling and land initialization on 2-m temperature predictions. JMA/MRI-CPS2 is capable of reasonably representing the seasonal cycle and secular trends of sea ice. The sea-ice coupling remarkably enhances the predictive capability for the Arctic 2-m temperature, indicating the importance of this factor, particularly for seasonal predictions in the Arctic region.

Introduction to "Tsunamis in the Pacific Ocean: 2011-2012"

NASA Astrophysics Data System (ADS)

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.

Geoethical issues involved in Tsunami Warning System concepts and operations

NASA Astrophysics Data System (ADS)

Charalampakis, Marinos; Papadopoulos, Gerassimos A.; Tinti, Stefano

2016-04-01

The main goal of a Tsunami Warning System (TWS) is to mitigate the effect of an incoming tsunami by alerting coastal population early enough to allow people to evacuate safely from inundation zones. Though this representation might seem oversimplified, nonetheless, achieving successfully this goal requires a positive synergy of geoscience, communication, emergency management, technology, education, social sciences, politics. Geoethical issues arise always when there is an interaction between geoscience and society, and TWS is a paradigmatic case where interaction is very strong and is made critical because a) the formulation of the tsunami alert has to be made in a time as short as possible and therefore on uncertain data, and b) any evaluation error (underestimation or overestimation) can lead to serious (and sometimes catastrophic) consequences involving wide areas and a large amount of population. From the geoethical point of view three issues are critical: how to (i) combine forecasts and uncertainties reasonably and usefully, (ii) cope and possibly solve the dilemma whether it is better over-alerting or under-alerting population and (iii) deal with responsibility and liability of geoscientists, TWS operators, emergency operators and coastal population. The discussion will be based on the experience of the Hellenic National Tsunami Warning Center (HL-NTWC, Greece), which operates on 24/7 basis as a special unit of the Institute of Geodynamics, National Observatory of Athens, and acts also as Candidate Tsunami Service Provider (CTSP) in the framework of the North-Eastern Atlantic, the Mediterranean and connected seas Tsunami Warning System (NEAMTWS) of the IOC/UNESCO. Since August 2012, when HL-NTWC was officially declared as operational, 14 tsunami warning messages have been disseminated to a large number of subscribers after strong submarine earthquakes occurring in Greece and elsewhere in the eastern Mediterranean. It is recognized that the alerting process and procedure are quite complex and deserve an open and wide debate, that at the moment seems to be absent from media, scientific community and society, very likely until the next tsunami disaster.

Post Fukushima tsunami simulations for Malaysian coasts

DOE Office of Scientific and Technical Information (OSTI.GOV)

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

Preliminary Report Summarizes Tsunami Impacts and Lessons Learned from the September 7, 2017, M8.1 Tehuantepec Earthquake

NASA Astrophysics Data System (ADS)

Wilson, R. I.; Ramirez-Herrera, M. T.; Dengler, L. A.; Miller, K.; LaDuke, Y.

2017-12-01

The preliminary tsunami impacts from the September 7, 2017, M8.1 Tehuantepec Earthquake have been summarized in the following report: https://www.eeri.org/wp-content/uploads/EERI-Recon-Rpt-090717-Mexico-tsunami_fn.pdf. Although the tsunami impacts were not as significant as those from the earthquake itself (98 fatalities and 41,000 homes damaged), the following are highlights and lessons learned: The Tehuantepec earthquake was one of the largest down-slab normal faulting events ever recorded. This situation complicated the tsunami forecast since forecast methods and pre-event modeling are primarily associated with megathrust earthquakes where the most significant tsunamis are generated. Adding non-megathrust source modeling to the tsunami forecast databases of conventional warning systems should be considered. Offshore seismic and tsunami hazard analyses using past events should incorporate the potential for large earthquakes occurring along sources other than the megathrust boundary. From an engineering perspective, initial reports indicate there was only minor tsunami damage along the Mexico coast. There was damage to Marina Chiapas where floating docks overtopped their piles. Increasing pile heights could reduce the potential for damage to floating docks. Tsunami warning notifications did not get to the public in time to assist with evacuation. Streamlining the messaging in Mexico from the warning system directly to the public should be considered. And, for local events, preparedness efforts should place emphasis on responding to feeling the earthquake and not waiting to be notified. Although the U.S. tsunami warning centers were timely with their international and domestic messaging, there were some issues with how those messages were presented and interpreted. The use of a "Tsunami Threat" banner on the new main warning center website created confusion with emergency managers in the U.S. where no tsunami threat was expected to exist. Also, some U.S. states and territories in the Pacific were listed in both domestic and international messages, which caused confusion for American Samoa where these messages contained somewhat conflicting information. These issues are being addressed by the warning centers and the U.S. National Tsunami Hazard Mitigation Program.

Floods and tsunamis.

PubMed

Llewellyn, Mark

2006-06-01

Floods and tsunamis cause few severe injuries, but those injuries can overwhelm local areas, depending on the magnitude of the disaster. Most injuries are extremity fractures, lacerations, and sprains. Because of the mechanism of soft tissue and bone injuries, infection is a significant risk. Aspiration pneumonias are also associated with tsunamis. Appropriate precautionary interventions prevent communicable dis-ease outbreaks. Psychosocial health issues must be considered.

Tsunami Risk Management in Pacific Island Countries and Territories (PICTs): Some Issues, Challenges and Ways Forward

NASA Astrophysics Data System (ADS)

Dominey-Howes, Dale; Goff, James

2013-09-01

The Pacific is well known for producing tsunamis, and events such as the 2011 Tōhoku-oki, Japan disaster demonstrate the vulnerability of coastal communities. We review what is known about the current state of tsunami risk management for Pacific Island countries and territories (PICTs), identify the issues and challenges associated with affecting meaningful tsunami disaster risk reduction (DRR) efforts and outline strategies and possible ways forward. Small island states are scattered across the vast Pacific region and these states have to varying degrees been affected by not only large tsunamis originating in circum-Pacific subduction zones, but also more regionally devastating events. Having outlined and described what is meant by the risk management process, the various problems associated with our current understanding of this process are examined. The poorly understood hazard related to local, regional and distant sources is investigated and the dominant focus on seismic events at the expense of other tsunami source types is noted. We reflect on the challenges of undertaking numerical modelling from generation to inundation and specifically detail the problems as they relate to PICTs. This is followed by an exploration of the challenges associated with mapping exposure and estimating vulnerability in low-lying coastal areas. The latter part of the paper is devoted to exploring what mitigation of the tsunami risk can look like and draw upon good practice cases as exemplars of the actions that can be taken from the local to regional level. Importantly, given the diversity of PICTs, no one approach will suit all places. The paper closes by making a series of recommendations to assist PICTs and the wider tsunami research community in thinking through improvements to their tsunami risk management processes and the research that can underpin these efforts.

Perceptions of earthquake and tsunami issues in U.S. Pacific Northwest port and harbor communities

USGS Publications Warehouse

Wood, Nathan J.; Good, James W.

2005-01-01

Although there is considerable energy focused on assessing natural hazards associated with earthquakes and tsunamis in the U.S. Pacific Northwest, little has been done to understand societal vulnerability to these hazards. Part of understanding societal vulnerability includes assessing the perceptions and priorities of public sector individuals with traditional emergency management responsibilities and of private citizens who could play key roles in community recovery. In response to this knowledge gap, we examine earthquake and tsunami perceptions of stakeholders and decision makers from coastal communities in the U.S. Pacific Northwest, focusing on perceptions of (1) regional hazards and societal vulnerability, (2) the current state of readiness, and (3) priorities for future hazard adjustment efforts. Results of a mailed survey suggest that survey participants believe that earthquakes and tsunamis are credible community threats. Most communities are focusing on regional mitigation and response planning, with less effort devoted to recovery plans or to making individual organizations more resilient. Significant differences in expressed perceptions and priorities were observed between Oregon and Washington respondents, mainly on tsunami issues. Significant perception differences were also observed between private and public sector respondents. Our results suggest the need for further research and for outreach and planning initiatives in the Pacific Northwest to address significant gaps in earthquake and tsunami hazard awareness and readiness.

Correlation between hypocenter depth, antecedent precipitation and earthquake-induced landslide spatial distribution

NASA Astrophysics Data System (ADS)

Fukuoka, Hiroshi; Watanabe, Eisuke

2017-04-01

Since Keefer published the paper on earthquake magnitude and affected area, maximum epicentral/fault distance of induced landslide distribution in 1984, showing the envelope of plots, a lot of studies on this topic have been conducted. It has been generally supposed that landslides have been triggered by shallow quakes and more landslides are likely to occur with heavy rainfalls immediately before the quake. In order to confirm this, we have collected 22 case records of earthquake-induced landslide distribution in Japan and examined the effect of hypocenter depth and antecedent precipitation. Earthquake magnitude by JMA (Japan Meteorological Agency) of the cases are from 4.5 to 9.0. Analysis on hycpocenter depth showed the deeper quake cause wider distribution. Antecedent precipitation was evaluated using the Soil Water Index (SWI), which was developed by JMA for issuing landslide alert. We could not find meaningful correlation between SWI and the earthquake-induced landslide distribution. Additionally, we found that smaller minimum size of collected landslides results in wider distribution especially between 1,000 to 100,000 m2.

A Pilot Tsunami Inundation Forecast System for Australia

NASA Astrophysics Data System (ADS)

Allen, Stewart C. R.; Greenslade, Diana J. M.

2016-12-01

The Joint Australian Tsunami Warning Centre (JATWC) provides a tsunami warning service for Australia. Warnings are currently issued according to a technique that does not include explicit modelling at the coastline, including any potential coastal inundation. This paper investigates the feasibility of developing and implementing tsunami inundation modelling as part of the JATWC warning system. An inundation model was developed for a site in Southeast Australia, on the basis of the availability of bathymetric and topographic data and observations of past tsunamis. The model was forced using data from T2, the operational deep-water tsunami scenario database currently used for generating warnings. The model was evaluated not only for its accuracy but also for its computational speed, particularly with respect to operational applications. Limitations of the proposed forecast processes in the Australian context and areas requiring future improvement are discussed.

Correction to “New maps of California to improve tsunami preparedness”

NASA Astrophysics Data System (ADS)

Barberopoulou, Aggeliki; Borrero, Jose C.; Uslu, Burak; Kalligeris, Nikos; Goltz, James D.; Wilson, Rick I.; Synolakis, Costas E.

2009-05-01

In the 21 April issue (Eos, 90(16), 2009), the article titled “New maps of California to improve tsunami preparedness” contained an error in its Figure 2 caption. Figure 2 is a map of Goleta, a city in Santa Barbara County. Thus, the first sentence of the caption should read, “Newly created tsunami inundation maps for Goleta, a city in Santa Barbara County, Calif., show the city's ‘wet line’ in black, representing the highest probable tsunami runup modeled for the region added to average water levels at high tide.” Eos deeply regrets this error.

The quest for wisdom: lessons from 17 tsunamis, 2004-2014.

PubMed

Okal, Emile A

2015-10-28

Since the catastrophic Sumatra-Andaman tsunami took place in 2004, 16 other tsunamis have resulted in significant damage and 14 in casualties. We review the fundamental changes that have affected our command of tsunami issues as scientists, engineers and decision-makers, in the quest for improved wisdom in this respect. While several scientific paradigms have had to be altered or abandoned, new algorithms, e.g. the W seismic phase and real-time processing of fast-arriving seismic P waves, give us more powerful tools to estimate in real time the tsunamigenic character of an earthquake. We assign to each event a 'wisdom index' based on the warning issued (or not) during the event, and on the response of the population. While this approach is admittedly subjective, it clearly shows several robust trends: (i) we have made significant progress in our command of far-field warning, with only three casualties in the past 10 years; (ii) self-evacuation by educated populations in the near field is a key element of successful tsunami mitigation; (iii) there remains a significant cacophony between the scientific community and decision-makers in industry and government as documented during the 2010 Maule and 2011 Tohoku events; and (iv) the so-called 'tsunami earthquakes' generating larger tsunamis than expected from the size of their seismic source persist as a fundamental challenge, despite scientific progress towards characterizing these events in real time. © 2015 The Author(s).

Developing Tsunami Evacuation Plans, Maps, And Procedures: Pilot Project in Central America

NASA Astrophysics Data System (ADS)

Arcos, N. P.; Kong, L. S. L.; Arcas, D.; Aliaga, B.; Coetzee, D.; Leonard, J.

2015-12-01

In the End-to-End tsunami warning chain, once a forecast is provided and a warning alert issued, communities must know what to do and where to go. The 'where to' answer would be reliable and practical community-level tsunami evacuation maps. Following the Exercise Pacific Wave 2011, a questionnaire was sent to the 46 Member States of Pacific Tsunami Warning System (PTWS). The results revealed over 42 percent of Member States lacked tsunami mass coastal evacuation plans. Additionally, a significant gap in mapping was exposed as over 55 percent of Member States lacked tsunami evacuation maps, routes, signs and assembly points. Thereby, a significant portion of countries in the Pacific lack appropriate tsunami planning and mapping for their at-risk coastal communities. While a variety of tools exist to establish tsunami inundation areas, these are inconsistent while a methodology has not been developed to assist countries develop tsunami evacuation maps, plans, and procedures. The International Tsunami Information Center (ITIC) and partners is leading a Pilot Project in Honduras demonstrating that globally standardized tools and methodologies can be applied by a country, with minimal tsunami warning and mitigation resources, towards the determination of tsunami inundation areas and subsequently community-owned tsunami evacuation maps and plans for at-risk communities. The Pilot involves a 1- to 2-year long process centered on a series of linked tsunami training workshops on: evacuation planning, evacuation map development, inundation modeling and map creation, tsunami warning & emergency response Standard Operating Procedures (SOPs), and conducting tsunami exercises (including evacuation). The Pilot's completion is capped with a UNESCO/IOC document so that other countries can replicate the process in their tsunami-prone communities.

The One-Meter Criterion for Tsunami Warning: Time for a Reevaluation?

NASA Astrophysics Data System (ADS)

Fryer, G. J.; Weinstein, S.

2013-12-01

The U.S. tsunami warning centers issue warnings when runup is anticipated to exceed one meter. The origins of the one-meter criterion are unclear, though Whitmore, et al (2008) showed from tsunami history that one meter is roughly the threshold above which damage occurs. Recent experiences in Hawaii, however, suggest that the threshold could be raised. Tsunami Warnings were issued for 2010 Chile, 2011 Tohoku, and 2012 Haida Gwaii tsunamis; each exceeded one meter runup somewhere in the State. Evacuation, however, was necessary only in 2011, and even then onshore damage (as opposed to damage from currents) occurred only where runup exceeded 1.5m. During both Chile and Haida Gwaii tsunamis the existing criteria led to unnecessary evacuation. Maximum runup during the Chile tsunami was 1.1m at Hilo's Wailoa Boat Harbor, while the Haida Gwaii tsunami peaked at 1.2m at Honouliwai Bay on Molokai. Both tsunamis caused only minor damage and minimal flooding; in both cases a Tsunami Advisory (i.e., there is no need to evacuate, but stay off the beach and out of the water) would have been adequate. The Advisory was originally developed as an ad hoc response to the mildly threatening 2006 Kuril tsunami and has since been formalized as the product we issue when maximum runup is expected to be 0.3-1.0 m. At the time it was introduced, however, there was no discussion that this new low-level warning might allow the criterion for Tsunami Warning itself to be adjusted. We now suggest that the divide between Advisory and Warning be raised from 1.0 to something greater, possibly 1.2m. If the warning threshold were raised to 1.2m, the over-warning for the Chile tsunami still could not have been avoided. Models calibrated against DART data consistently forecast runup just over 1.2m for that event. For Haida Gwaii, adjusting the models to match the DART data increased the forecast runup to almost 2m, which again meant a warning, though in retrospect we should have been skeptical. The nearest DART to Haida Gwaii was off the Washington coast in line with the long axis (strike direction) of the rupture and so provided little constraint on the tsunami directed towards Hawaii (the dip direction). The finite fault model obtained by inverting the DART data extended the rupture too far along strike and pushed the rupture to the wrong (east) side of Haida Gwaii, in conflict with the W-phase CMT. The inferred wave height at the Langara Point tide gauge, just outside the epicentral region, was also too large by a factor of two. Forcing the tsunami inversion to be consistent with the CMT would have rendered the inferred rupture much closer to reality, matched the Langara Point record well, and forecast a maximum runup at Kahului of only 1.0 m (the actual runup there was 0.8m). If the warning criterion had been 1.2m the unnecessary coastal evacuation for the Haida Gwaii tsunami could have been avoided. So increasing the warning threshold by only 20 cm would eliminate one of the two recent unnecessary evacuations. Can the threshold be be raised even more? We are considering that possibility, though the uncertainties and time constraints of an actual warning demand that we remain very conservative.

Assessment of the Initial Response from Tsunami Monitoring Services Provided to the Northeastern Caribbean

NASA Astrophysics Data System (ADS)

Soto-Cordero, L.; Meltzer, A.

2014-12-01

A mag 6.4 earthquake offshore northern Puerto Rico earlier this year (1/13/14) is a reminder of the high risk of earthquakes and tsunamis in the northeastern Caribbean. Had the magnitude of this event been 0.1 larger (M 6.5) a tsunami warning would have been issued for the Puerto Rico-Virgin Islands (PRVI) region based on the West Coast Alaska Tsunami Warning Center (WCATWC) and Puerto Rico Seismic Network (PRSN) response procedures at the time. Such an alert level would have led local authorities to issue evacuation orders for all PRVI coastal areas. Since the number of deaths associated with tsunamis in the Caribbean region is greater than the total casualties from tsunamis in the entire US (including Hawaii and Alaska coasts) having an effective and redundant warning system is critical in order to save lives and to minimize false alarms that could result in significant economic costs and loss of confidence of Caribbean residents. We are evaluating three fundamental components of tsunami monitoring protocols currently in place in the northeastern Caribbean: 1) preliminary earthquake parameters (used to determine the potential that a tsunami will be generated and the basis of tsunami alert levels), 2) adequacy of the tsunami alert levels, and 3) tsunami message dissemination. We compiled a catalog of earthquake locations (2007-2014) and dissemination times from the PTWC, WCATWC and NEIC (final locations). The events were classified into 3 categories: local [17°-20°N, 63.5°-69°W], regional (Caribbean basin) and distant/teleseismic (Atlantic basin). A total of 104 local earthquakes, 31 regional and 25 distant events were analyzed. We found that in general preliminary epicentral locations have an accuracy of 40 km. 64% of local events were located with an accuracy of 20 km. The depth accuracy of local events shallower than 50 km, regional and distant earthquakes is usually smaller than 30 km. For deeper local events the error distribution shows more variability (-32 to 81 km); preliminary locations tend to underestimate depth. A trade-off between epicentral location and depth was observed for several local events deeper than 50 km.

Application of binary diagnostic ratios of polycyclic aromatic hydrocarbons for identification of Tsunami 2004 backwash sediments in Khao Lak, Thailand.

PubMed

Pongpiachan, Siwatt

2014-01-01

Identification of Tsunami deposits has long been a controversial issue among geologists. Although there are many identification criteria based on the sedimentary characteristics of unequivocal Tsunami deposits, the concept still remains ambiguous. Apart from relying on some conventional geological, sedimentological, and geoscientific records, geologists need some alternative "proxies" to identify the existence of Tsunami backwash in core sediments. Polycyclic aromatic hydrocarbons (PAHs) are a class of very stable organic molecules, which can usually be presented as complex mixtures of several hundred congeners; one can assume that the "Tsunami backwash deposits" possess different fingerprints of PAHs apart from those of "typical marine sediments." In this study, three-dimensional plots of PAH binary ratios successfully identify the Tsunami backwash deposits in comparison with those of global marine sediments. The applications of binary ratios of PAHs coupled with HCA are the basis for developing site-specific Tsunami deposit identification criteria that can be applied in paleotsunami deposits investigations.

Tsunami disaster risk management capabilities in Greece

NASA Astrophysics Data System (ADS)

Marios Karagiannis, Georgios; Synolakis, Costas

2015-04-01

Greece is vulnerable to tsunamis, due to the length of the coastline, its islands and its geographical proximity to the Hellenic Arc, an active subduction zone. Historically, about 10% of all world tsunamis occur in the Mediterranean region. Here we review existing tsunami disaster risk management capabilities in Greece. We analyze capabilities across the disaster management continuum, including prevention, preparedness, response and recovery. Specifically, we focus on issues like legal requirements, stakeholders, hazard mitigation practices, emergency operations plans, public awareness and education, community-based approaches and early-warning systems. Our research is based on a review of existing literature and official documentation, on previous projects, as well as on interviews with civil protection officials in Greece. In terms of tsunami disaster prevention and hazard mitigation, the lack of tsunami inundation maps, except for some areas in Crete, makes it quite difficult to get public support for hazard mitigation practices. Urban and spatial planning tools in Greece allow the planner to take into account hazards and establish buffer zones near hazard areas. However, the application of such ordinances at the local and regional levels is often difficult. Eminent domain is not supported by law and there are no regulatory provisions regarding tax abatement as a disaster prevention tool. Building codes require buildings and other structures to withstand lateral dynamic earthquake loads, but there are no provisions for resistance to impact loading from water born debris Public education about tsunamis has increased during the last half-decade but remains sporadic. In terms of disaster preparedness, Greece does have a National Tsunami Warning Center (NTWC) and is a Member of UNESCO's Tsunami Program for North-eastern Atlantic, the Mediterranean and connected seas (NEAM) region. Several exercises have been organized in the framework of the NEAM Tsunami Warning System, with the Greek NWTC actively participating as a Candidate Tsunami Watch Provider. In addition, Greece designed and conducted the first tsunami exercise program in the Union Civil Protection Mechanism in 2011, which also considered the attrition of response capabilities by the earthquake generating the tsunami. These exercises have demonstrated the capability of the Greek NWTC to provide early warning to local civil protection authorities, but warning dissemination to the population remains an issue, especially during the summer season. However, there is no earthquake or tsunami national emergency operations plan, and we found that tsunami disaster planning and preparedness activities are rather limited at the local level. We acknowledge partial support by the project ASTARTE (Assessment, STrategy And Risk Reduction for Tsunamis in Europe) FP7-ENV2013 6.4-3, Grant 603839 to the Technical University of Crete.

Vulnerability of the Built Environment to Tsunamis - an Overview of Where We Are in 2012

NASA Astrophysics Data System (ADS)

Petroff, C. M.

2012-12-01

The last twenty years have seen great strides in the understanding and prediction of tsunami behavior. Though study of these disasters has always been motivated by the need to reduce casualties and damage, early work focused primarily on predicting magnitude, propagation and inundation from tsunami waves. Investigations have expanded to include a burgeoning field concentrated on the landward effects of tsunamis on communities: examining building and infrastructure vulnerability, assessing the probabilities of varying levels of damage and applying these findings to planning of land-use, development, evacuation and response. Catastrophic events of the last decade in the Indian Ocean and Japan have brought these issues to the fore and raise the question: Where are we in our understanding of vulnerability to tsunamis? What have we learned? What are the lessons that the most recent events teach us? This overview summarizes recent investigations of the vulnerability of engineered structures to damage from tsunamis - from individual buildings of various uses to larger facilities and structural systems. Examples are provided of both successes and failures in design for tsunami resistance. Vulnerability of critical infrastructure and lifelines is discussed in the context of tsunamis in Sumatra, Chile and Japan. This includes the ability of critical systems to function during and immediately after a disaster as well as the short and long term resilience of utilities, services and coastal facilities after tsunamis. Recent work on probabilistic prediction of damage and development of fragility functions is summarized for the Chile 2010 and Japan 2011 tsunamis. Finally, a commentary is presented on building vulnerability issues as they relate to land use planning, building design and codes and vertical evacuation planning.; Three views of the Oya Train Station in Miyagi Prefecture: Prior to (top), two months after (middle), and one year after (bottom) the March 11, 2011 Tohoku Japan tsunami. The top view shows the rail line, shops, residences, coastal vegetation, tourist beach and coastal slope protection. All these were damaged or destroyed in the tsunami. One year after, a sand bag barrier had been installed inland of remaining low profile shore protection at Oya Kaigan. Rail lines had not been replaced and the station building remained closed. The area remained evacuated. Power line installation and road repairs were complete. (top photo courtesy F. Imamura)

The FASTER Approach: A New Tool for Calculating Real-Time Tsunami Flood Hazards

NASA Astrophysics Data System (ADS)

Wilson, R. I.; Cross, A.; Johnson, L.; Miller, K.; Nicolini, T.; Whitmore, P.

2014-12-01

In the aftermath of the 2010 Chile and 2011 Japan tsunamis that struck the California coastline, emergency managers requested that the state tsunami program provide more detailed information about the flood potential of distant-source tsunamis well ahead of their arrival time. The main issue is that existing tsunami evacuation plans call for evacuation of the predetermined "worst-case" tsunami evacuation zone (typically at a 30- to 50-foot elevation) during any "Warning" level event; the alternative is to not call an evacuation at all. A solution to provide more detailed information for secondary evacuation zones has been the development of tsunami evacuation "playbooks" to plan for tsunami scenarios of various sizes and source locations. To determine a recommended level of evacuation during a distant-source tsunami, an analytical tool has been developed called the "FASTER" approach, an acronym for factors that influence the tsunami flood hazard for a community: Forecast Amplitude, Storm, Tides, Error in forecast, and the Run-up potential. Within the first couple hours after a tsunami is generated, the National Tsunami Warning Center provides tsunami forecast amplitudes and arrival times for approximately 60 coastal locations in California. At the same time, the regional NOAA Weather Forecast Offices in the state calculate the forecasted coastal storm and tidal conditions that will influence tsunami flooding. Providing added conservatism in calculating tsunami flood potential, we include an error factor of 30% for the forecast amplitude, which is based on observed forecast errors during recent events, and a site specific run-up factor which is calculated from the existing state tsunami modeling database. The factors are added together into a cumulative FASTER flood potential value for the first five hours of tsunami activity and used to select the appropriate tsunami phase evacuation "playbook" which is provided to each coastal community shortly after the forecast is provided.

Local Tsunami Warnings using GNSS and Seismic Data.

NASA Astrophysics Data System (ADS)

Hirshorn, B. F.

2017-12-01

Tsunami warning Centers (TWC's) must issue warnings based on imperfect and limited data. Uncertainties increase in the near field, where a tsunami reaches the closest coastal populations to the causative earthquake in a half hour or less. In the absence of a warning, the usual advice is "When the ground shakes so severely that it's difficult to stand, move uphill and away from the coast." But, what if the shaking is not severe? If, for example, the earthquake ruptures slowly (producing very little perceived shaking) this advice will fail. Unfortunately these "Tsunami" earthquakes are not rare: tsunamis from slow earthquakes off of Nicaragua in 1992, and Java in 1994 and 2006, killed 179, 250 and 637 people, respectively, even though very few nearby coastal residents felt any strong ground shaking. TWC's must therefore warn the closest coastal populations to the causative earthquake, where over 80% of the Tsunami based casualties typically occur, as soon possible after earthquake rupture begins. The NWS Tsunami Warning Centers (TWCs) currently issue local Tsunami Warnings for the US West Coast, Hawaii, and the Puerto Rico - Virgin Island region within 2-4 minutes after origin time. However, our initial short period Magnitude estimates saturate over about Mw 6.5, and Mwp underestimates Mw for events larger than about Mw 7.5 when using data in the 0 to 3 degree epicentral distance range, severely underestimating the danger of a potential Tsunami in the near field. Coastal GNSS networks complement seismic monitoring networks, and enable unsaturated estimates of Mw within 2-3 minutes of earthquake origin time. NASA/JPL, SIO, USGS, CWU, UCB and UW, with funding and guidance from NASA, and leveraging the USGS funded ShakeAlert development, have been working with the National Weather Service TWC's to incorporate real-time GNSS and seismogeodetic data into their operations. These data will soon provide unsaturated estimates of moment magnitude, Centroid Moment Tensor solutions, coseismic crustal deformation, and fault slip models within a few minutes after earthquake initiation. The sea floor deformation associated with the earthquake slip can then be used as an initial condition for an automatically generated tsunami propagation and coastal inundation model for coastal warnings.

A comparison between two inundation models for the 25 Ooctober 2010 Mentawai Islands Tsunami

NASA Astrophysics Data System (ADS)

Huang, Z.; Borrero, J. C.; Qiu, Q.; Hill, E. M.; Li, L.; Sieh, K. E.

2011-12-01

On 25 October 2010, an Mw~7.8 earthquake occurred on the Sumatra megathrust seaward of the Mentawai Islands, Indonesia, generating a tsunami which killed approximately 500 people. Following the event, the Earth Observatory of Singapore (EOS) initiated a post-tsunami field survey, collecting tsunami run-up data from more than 30 sites on Pagai Selatan, Pagai Utara and Sipora. The strongest tsunami effects were observed on several small islands offshore of Pagai Selatan, where runup exceeded 16 m. This presentation will focus on a detailed comparison between two tsunami propagation and inundation models: COMCOT (Cornell Multi-grid Coupled Tsunami model) and MOST (Method of Splitting Tsunami). Simulations are initialized using fault models based on data from a 1-hz GPS system that measured co-seismic deformation throughout the region. Preliminary simulations suggest that 2-m vertical seafloor deformation over a reasonably large area is required to recreate most of the observed tsunami effects. Since the GPS data suggest that subsidence of the islands is small, this implies that the tsunami source region is somewhat narrower and located further offshore than described in recently published earthquake source models based on teleseismic inversions alone. We will also discuss issues such as bathymetric and topographic data preparation and the uncertainty in the modeling results due to the lack of high resolution bathymetry and topography in the study area.

CARIBE WAVE/LANTEX Caribbean and Western Atlantic Tsunami Exercises

NASA Astrophysics Data System (ADS)

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 Seismic Network. The CARIBE WAVE/LANTEX 13 scenario simulated a tsunami generated by a magnitude 8.5 earthquake originating north of Oranjestad, Aruba in the Caribbean Sea. For the first time earthquake impact was included in addition to expected tsunami impact. The initial message was issued by the warning centers over the established channels, while different mechanisms were then used by participants for further dissemination. The enhanced PTWC tsunami products for the Caribbean were also made available to the participants. To provide feedback on the exercise an online survey tool with 85 questions was used. The survey demonstrated satisfaction with exercise, timely receipt of bulletins and interest in the enhanced PTWC products. It also revealed that while 93% of the countries had an activation and response process, only 59% indicated that they also had an emergency response plan for tsunamis and even fewer had tsunami evacuation plans and inundation maps. Given that 80% of those surveyed indicated that CARIBE WAVE should be conducted annually, CARIBE EWS decided that the next exercise be held on March 26, 2014, instead of waiting until 2015.

Lessons unlearned in Japan before 2011: Effects of the 2004 Indian Ocean tsunami on a nuclear plant in India

NASA Astrophysics Data System (ADS)

Sugimoto, M.

2015-12-01

The 2004 Indian Ocean tsunami killed around 220,000 people and startled the world. North of Chennai (Madras), the Indian plant nearly affected by tsunami in 2004. The local residents really did not get any warning in India. "On December 26, the Madras Atomic Power Station looked like a desolate place with no power, no phones, no water, no security arrangement and no hindrance whatsoever for outsiders to enter any part of the plant," said S.P. Udaykumar of SACCER. Nuclear issues hide behind such big tsunami damaged. Few media reported outside India. As for US, San Francisco Chronicle reported scientists had to rethink about nuclear power plants by the 2004 tsunami in 11th July 2005. Few tsunami scientsts did not pay attention to nucler power plants nearly affected by tsunami in US. On the other hand, US government noticed the Indian plant nearly affected in 2004. US Goverment supported nucler disaster management in several countries. As for Japan, Japanese goverment mainly concentrated reconstrucation in affected areas and tsunami early warning system. I worked in Japanese embassy in Jakarta Indonesia at that time. I did not receive the information about the Indian plant nearly affected by tsunami and US supported nucler safety to the other coutries. The 2011 Tohoku earthquake and tsunami damaged society and nuclear power stations. The Fukushima Dai-ichi Nuclear Power Plant (FDNPP) accident resulted in the largest release of radioactive material since the 1986 Chernobyl accident. Why did not Japanese tsunami scientists learn from warning signs from the nuclear plant in India by the 2004 Indian Ocean tsunami to the 2011 Fukushima accident? I would like to clarify the reason few tsunami scientist notice this point in my presentation.

Challenges in Defining Tsunami Wave Height

NASA Astrophysics Data System (ADS)

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.

Challenges in Defining Tsunami Wave Heights

NASA Astrophysics Data System (ADS)

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 deep-ocean buoy, NCEI will consider adding an additional field for the maximum peak measurement.

Tsunami simulation method initiated from waveforms observed by ocean bottom pressure sensors for real-time tsunami forecast; Applied for 2011 Tohoku Tsunami

NASA Astrophysics Data System (ADS)

Tanioka, Yuichiro

2017-04-01

After tsunami disaster due to the 2011 Tohoku-oki great earthquake, improvement of the tsunami forecast has been an urgent issue in Japan. National Institute of Disaster Prevention is installing a cable network system of earthquake and tsunami observation (S-NET) at the ocean bottom along the Japan and Kurile trench. This cable system includes 125 pressure sensors (tsunami meters) which are separated by 30 km. Along the Nankai trough, JAMSTEC already installed and operated the cable network system of seismometers and pressure sensors (DONET and DONET2). Those systems are the most dense observation network systems on top of source areas of great underthrust earthquakes in the world. Real-time tsunami forecast has depended on estimation of earthquake parameters, such as epicenter, depth, and magnitude of earthquakes. Recently, tsunami forecast method has been developed using the estimation of tsunami source from tsunami waveforms observed at the ocean bottom pressure sensors. However, when we have many pressure sensors separated by 30km on top of the source area, we do not need to estimate the tsunami source or earthquake source to compute tsunami. Instead, we can initiate a tsunami simulation from those dense tsunami observed data. Observed tsunami height differences with a time interval at the ocean bottom pressure sensors separated by 30 km were used to estimate tsunami height distribution at a particular time. In our new method, tsunami numerical simulation was initiated from those estimated tsunami height distribution. In this paper, the above method is improved and applied for the tsunami generated by the 2011 Tohoku-oki great earthquake. Tsunami source model of the 2011 Tohoku-oki great earthquake estimated using observed tsunami waveforms, coseimic deformation observed by GPS and ocean bottom sensors by Gusman et al. (2012) is used in this study. The ocean surface deformation is computed from the source model and used as an initial condition of tsunami simulation. By assuming that this computed tsunami is a real tsunami and observed at ocean bottom sensors, new tsunami simulation is carried out using the above method. The station distribution (each station is separated by 15 min., about 30 km) observed tsunami waveforms which were actually computed from the source model. Tsunami height distributions are estimated from the above method at 40, 80, and 120 seconds after the origin time of the earthquake. The Near-field Tsunami Inundation forecast method (Gusman et al. 2014) was used to estimate the tsunami inundation along the Sanriku coast. The result shows that the observed tsunami inundation was well explained by those estimated inundation. This also shows that it takes about 10 minutes to estimate the tsunami inundation from the origin time of the earthquake. This new method developed in this paper is very effective for a real-time tsunami forecast.

Issues of tsunami hazard maps revealed by the 2011 Tohoku tsunami

NASA Astrophysics Data System (ADS)

Sugimoto, M.

2013-12-01

Tsunami scientists are imposed responsibilities of selection for people's tsunami evacuation place after the 2011 Tohoku Tsunami in Japan. A lot of matured people died out of tsunami hazard zone based on tsunami hazard map though students made a miracle by evacuation on their own judgment in Kamaishi city. Tsunami hazard maps were based on numerical model smaller than actual magnitude 9. How can we bridge the gap between hazard map and future disasters? We have to discuss about using tsunami numerical model better enough to contribute tsunami hazard map. How do we have to improve tsunami hazard map? Tsunami hazard map should be revised included possibility of upthrust or downthrust after earthquakes and social information. Ground sank 1.14m below sea level in Ayukawa town, Tohoku. Ministry of Land, Infrastructure, Transport and Tourism's research shows around 10% people know about tsunami hazard map in Japan. However, people know about their evacuation places (buildings) through experienced drills once a year even though most people did not know about tsunami hazard map. We need wider spread of tsunami hazard with contingency of science (See the botom disaster handbook material's URL). California Emergency Management Agency (CEMA) team practically shows one good practice and solution to me. I followed their field trip in Catalina Island, California in Sep 2011. A team members are multidisciplinary specialists: A geologist, a GIS specialist, oceanographers in USC (tsunami numerical modeler) and a private company, a local policeman, a disaster manager, a local authority and so on. They check field based on their own specialties. They conduct an on-the-spot inspection of ambiguous locations between tsunami numerical model and real field conditions today. The data always become older. They pay attention not only to topographical conditions but also to social conditions: vulnerable people, elementary schools and so on. It takes a long time to check such field information, however tsunami hazard map based on numerical model should be this process. Tsunami scientists should not enter into the inhumane business by using tsunami numerical model. It includes accountability to society therefore scientists need scientific ethics and humanitarian attention. Should only tsunami scientist have responsibility for human life? Multidisciplinary approach is essential for mitigation like CEMA. I am taking on hazard map training course for disaster management officers from developing countries in JICA training course. I would like to discuss how to improve tsunami hazard map after the 2011 Tohoku tsunami experience in this presentation. A multidisciplinary exparts team of CEMA's tsunami hazard map

A protocol for coordinating post-tsunami field reconnaissance efforts in the USA

USGS Publications Warehouse

Wilson, Rick I.; Wood, Nathan J.; Kong, Laura; Shulters, Michael V.; Richards, Kevin D.; Dunbar, Paula; Tamura, Gen; Young, Edward J.

2015-01-01

In the aftermath of a catastrophic tsunami, much is to be learned about tsunami generation and propagation, landscape and ecological changes, and the response and recovery of those affected by the disaster. Knowledge of the impacted area directly helps response and relief personnel in their efforts to reach and care for survivors and for re-establishing community services. First-hand accounts of tsunami-related impacts and consequences also help researchers, practitioners, and policy makers in other parts of the world that lack recent events to better understand and manage their own societal risks posed by tsunami threats. Conducting post-tsunami surveys and disseminating useful results to decision makers in an effective, efficient, and timely manner is difficult given the logistical issues and competing demands in a post-disaster environment. To facilitate better coordination of field-data collection and dissemination of results, a protocol for coordinating post-tsunami science surveys was developed by a multi-disciplinary group of representatives from state and federal agencies in the USA. This protocol is being incorporated into local, state, and federal post-tsunami response planning through the efforts of the Pacific Risk Management ‘Ohana, the U.S. National Tsunami Hazard Mitigation Program, and the U.S. National Plan for Disaster Impact Assessments. Although the protocol was designed to support a coordinated US post-tsunami response, we believe it could help inform post-disaster science surveys conducted elsewhere and further the discussion on how hazard researchers can most effectively operate in disaster environments.

Public Perceptions of Tsunamis and the NOAA TsunamiReady Program in Los Angeles

NASA Astrophysics Data System (ADS)

Rosati, A.

2010-12-01

After the devastating December 2004 Indian Ocean Tsunami, California and other coastal states began installing "Tsunami Warning Zone" and "Evacuation Route" signs at beaches and major access roads. The geography of the Los Angeles area may not be conducive to signage alone for communication of the tsunami risk and safety precautions. Over a year after installation, most people surveyed did not know about or recognize the tsunami signs. More alarming is that many did not believe a tsunami could occur in the area even though earthquake generated waves have reached nearby beaches as recently as September 2009! UPDATE: FEB. 2010. Fifty two percent of the 147 people surveyed did not believe they would survive a natural disaster in Los Angeles. Given the unique geography of Los Angeles, how can the city and county improve the mental health of its citizens before and after a natural disaster? This poster begins to address the issues of community self-efficacy and resiliency in the face of tsunamis. Of note for future research, the data from this survey showed that most people believed climate change would increase the occurrence of tsunamis. Also, the public understanding of water inundation was disturbingly low. As scientists, it is important to understand the big picture of our research - how it is ultimately communicated, understood, and used by the public.

Analysis of Tsunami Evacuation Issues Using Agent Based Modeling. A Case Study of the 2011 Tohoku Tsunami in Yuriage, Natori.

NASA Astrophysics Data System (ADS)

Mas, E.; Takagi, H.; Adriano, B.; Hayashi, S.; Koshimura, S.

2014-12-01

The 2011 Great East Japan earthquake and tsunami reminded that nature can exceed structural countermeasures like seawalls, breakwaters or tsunami gates. In such situations it is a challenging task for people to find nearby haven. This event, as many others before, confirmed the importance of early evacuation, tsunami awareness and the need for developing much more resilient communities with effective evacuation plans. To support reconstruction activities and efforts on developing resilient communities in areas at risk, tsunami evacuation simulation can be applied to tsunami mitigation and evacuation planning. In this study, using the compiled information related to the evacuation behavior at Yuriage in Natori during the 2011 tsunami, we simulated the evacuation process and explored the reasons for the large number of fatalities in the area. It was found that residents did evacuate to nearby shelter areas, however after the tsunami warning was increased some evacuees decided to conduct a second step evacuation to a far inland shelter. Simulation results show the consequences of such decision and the outcomes when a second evacuation would not have been performed. The actual reported number of fatalities in the event and the results from simulation are compared to verify the model. The case study shows the contribution of tsunami evacuation models as tools to be applied for the analysis of evacuees' decisions and the related outcomes. In addition, future evacuation plans and activities for reconstruction process and urban planning can be supported by the results provided from this kind of tsunami evacuation models.

Reducing the age range of tsunami deposits by 14C dating of rip-up clasts

NASA Astrophysics Data System (ADS)

Ishizawa, Takashi; Goto, Kazuhisa; Yokoyama, Yusuke; Miyairi, Yosuke; Sawada, Chikako; Takada, Keita

2018-02-01

Erosion by tsunami waves represents an important issue when determining the age of a tsunami deposit, because the age is usually estimated using dating of sediments above and below the deposit. Dating of material within the tsunami deposit, if suitable material is obtainable, can be used to further constrain its age. Eroded sediments are sometimes incorporated within the tsunami deposits as rip-up clasts, which might therefore be used as minimum age dating material. However, the single calibrated 14C age often shows a wide age range because of fluctuations in the calibration curve. Therefore, it remains uncertain whether rip-up clast measurements are useful to constrain the depositional age of tsunami deposits, or not. In this study, we carried out high-resolution 14C dating of tsunami deposits, including rip-up clasts of peat, in Rikuzentakata, northeastern Japan, where numerous rip-up clasts were observed within a tsunami deposit. Sediments above and below the tsunami deposit and a 5 cm large rip-up clast were dated sequentially. Comparison of these dating results with the calibration curve revealed that the clast was inverted. Its age was better constrained based on the stratigraphic order, and we infer that the clast corresponds to approximately 100 years of sedimentation. The oldest age of the clast was consistent with the age of the peat immediately below the tsunami deposit, suggesting that surface sediments probably formed the rip-up clast at the time of the tsunami. Thus, the dating of the rip-up clast was useful to further constrain the depositional age of the tsunami deposit, as we narrowed the tsunami deposit age range by approximately 100 years. Results show that ignoring tsunami-related erosion might lead to overestimation of the tsunami deposit age. For this reason, an appropriate dating site, which is less affected by minor tsunami-related erosion with regards to the paleo-topography, should be explored. We therefore propose a more effective sampling strategy for better age estimation of tsunami deposits.

Using GPS to Detect Imminent Tsunamis

NASA Technical Reports Server (NTRS)

Song, Y. Tony

2009-01-01

A promising method of detecting imminent tsunamis and estimating their destructive potential involves the use of Global Positioning System (GPS) data in addition to seismic data. Application of the method is expected to increase the reliability of global tsunami-warning systems, making it possible to save lives while reducing the incidence of false alarms. Tsunamis kill people every year. The 2004 Indian Ocean tsunami killed about 230,000 people. The magnitude of an earthquake is not always a reliable indication of the destructive potential of a tsunami. The 2004 Indian Ocean quake generated a huge tsunami, while the 2005 Nias (Indonesia) quake did not, even though both were initially estimated to be of the similar magnitude. Between 2005 and 2007, five false tsunami alarms were issued worldwide. Such alarms result in negative societal and economic effects. GPS stations can detect ground motions of earthquakes in real time, as frequently as every few seconds. In the present method, the epicenter of an earthquake is located by use of data from seismometers, then data from coastal GPS stations near the epicenter are used to infer sea-floor displacements that precede a tsunami. The displacement data are used in conjunction with local topographical data and an advanced theory to quantify the destructive potential of a tsunami on a new tsunami scale, based on the GPS-derived tsunami energy, much like the Richter Scale used for earthquakes. An important element of the derivation of the advanced theory was recognition that horizontal sea-floor motions contribute much more to generation of tsunamis than previously believed. The method produces a reliable estimate of the destructive potential of a tsunami within minutes typically, well before the tsunami reaches coastal areas. The viability of the method was demonstrated in computational tests in which the method yielded accurate representations of three historical tsunamis for which well-documented ground-motion measurements were available. Development of a global tsunami-warning system utilizing an expanded network of coastal GPS stations was under consideration at the time of reporting the information for this article.

The Redwood Coast Tsunami Work Group: Promoting Earthquake and Tsunami Resilience on California's North Coast

NASA Astrophysics Data System (ADS)

Dengler, L. A.; Henderson, C.; Larkin, D.; Nicolini, T.; Ozaki, V.

2014-12-01

In historic times, Northern California has suffered the greatest losses from tsunamis in the U.S. contiguous 48 states. 39 tsunamis have been recorded in the region since 1933, including five that caused damage. This paper describes the Redwood Coast Tsunami Work Group (RCTWG), an organization formed in 1996 to address the tsunami threat from both near and far sources. It includes representatives from government agencies, public, private and volunteer organizations, academic institutions, and individuals interested in working to reduce tsunami risk. The geographic isolation and absence of scientific agencies such as the USGS and CGS in the region, and relatively frequent occurrence of both earthquakes and tsunami events has created a unique role for the RCTWG, with activities ranging from basic research to policy and education and outreach programs. Regional interest in tsunami issues began in the early 1990s when there was relatively little interest in tsunamis elsewhere in the state. As a result, the group pioneered tsunami messaging and outreach programs. Beginning in 2008, the RCTWG has partnered with the National Weather Service and the California Office of Emergency Services in conducting the annual "live code" tsunami communications tests, the only area outside of Alaska to do so. In 2009, the RCTWG joined with the Southern California Earthquake Alliance and the Bay Area Earthquake Alliance to form the Earthquake Country Alliance to promote a coordinated and consistent approach to both earthquake and tsunami preparedness throughout the state. The RCTWG has produced and promoted a variety of preparedness projects including hazard mapping and sign placement, an annual "Earthquake - Tsunami Room" at County Fairs, public service announcements and print material, assisting in TsunamiReady community recognition, and facilitating numerous multi-agency, multidiscipline coordinated exercises, and community evacuation drills. Nine assessment surveys from 1993 to 2013 have tracked preparedness actions and personal awareness of tsunami hazards. Over the twenty-year period covered by the surveys, respondents aware of a local tsunami hazard increased from 51 to 90 percent and awareness of the Cascadia subduction zone increased from 16 to 60 percent.

The Dependency of Probabilistic Tsunami Hazard Assessment on Magnitude Limits of Seismic Sources in the South China Sea and Adjoining Basins

NASA Astrophysics Data System (ADS)

Li, Hongwei; Yuan, Ye; Xu, Zhiguo; Wang, Zongchen; Wang, Juncheng; Wang, Peitao; Gao, Yi; Hou, Jingming; Shan, Di

2017-06-01

The South China Sea (SCS) and its adjacent small basins including Sulu Sea and Celebes Sea are commonly identified as tsunami-prone region by its historical records on seismicity and tsunamis. However, quantification of tsunami hazard in the SCS region remained an intractable issue due to highly complex tectonic setting and multiple seismic sources within and surrounding this area. Probabilistic Tsunami Hazard Assessment (PTHA) is performed in the present study to evaluate tsunami hazard in the SCS region based on a brief review on seismological and tsunami records. 5 regional and local potential tsunami sources are tentatively identified, and earthquake catalogs are generated using Monte Carlo simulation following the Tapered Gutenberg-Richter relationship for each zone. Considering a lack of consensus on magnitude upper bound on each seismic source, as well as its critical role in PTHA, the major concern of the present study is to define the upper and lower limits of tsunami hazard in the SCS region comprehensively by adopting different corner magnitudes that could be derived by multiple principles and approaches, including TGR regression of historical catalog, fault-length scaling, tectonic and seismic moment balance, and repetition of historical largest event. The results show that tsunami hazard in the SCS and adjoining basins is subject to large variations when adopting different corner magnitudes, with the upper bounds 2-6 times of the lower. The probabilistic tsunami hazard maps for specified return periods reveal much higher threat from Cotabato Trench and Sulawesi Trench in the Celebes Sea, whereas tsunami hazard received by the coasts of the SCS and Sulu Sea is relatively moderate, yet non-negligible. By combining empirical method with numerical study of historical tsunami events, the present PTHA results are tentatively validated. The correspondence lends confidence to our study. Considering the proximity of major sources to population-laden cities around the SCS region, the tsunami hazard and risk should be further highlighted in the future.

Community participation in tsunami early warning system in Pangandaran town

NASA Astrophysics Data System (ADS)

Hadian, Sapari D.; Khadijah, Ute Lies Siti; Saepudin, Encang; Budiono, Agung; Yuliawati, Ayu Krishna

2017-07-01

Disaster-resilient communities are communities capable of anticipating and minimizing destructive forces through adaptation. Disaster is an event very close to the people of Indonesia, especially in the small tourism town of Pangadaran located at West Java, Indonesia. On July 17, 2006, the town was hit by a Mw 7.8 earthquake and tsunami that effected over 300 km of the coastline, where the community suffered losses in which more than 600 people were killed, with run up heights exceeding 20 m. The devastation of the tsunami have made the community more alert and together with the local government and other stakeholder develop an Early Warning System for Tsunami. The study is intended to discover issues on tsunami Early Warning System (EWS), disaster risk reduction measures taken and community participation. The research method used is descriptive and explanatory research. The study describe the Tsunami EWS and community based Disaster Risk Reduction in Pangandaran, the implementation of Tsunami alert/EWS in disaster preparedness and observation of community participation in EWS. Data were gathered by secondary data collection, also primary data through interviews, focus group discussions and field observations. Research resulted in a description of EWS implementation, community participation and recommendation to reduce disaster risk in Pangandaran.

Anatomy of Historical Tsunamis: Lessons Learned for Tsunami Warning

NASA Astrophysics Data System (ADS)

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 under the United Nations. This paper reviews historical tsunamis, their warning activities, and their sea level records to highlight lessons learned with the focus on how these insights have helped to drive further development of tsunami warning systems and their tsunami warning centers. While the international systems do well for teletsunamis, faster detection, more accurate evaluations, and widespread timely alerts are still the goals, and challenges still remain to achieving early warning against the more frequent and destructive local tsunamis.

Geoethics and decision science issues in Japan's disaster management system: case study in the 2011 Tohoku earthquake and tsunami

NASA Astrophysics Data System (ADS)

Sugimoto, Megumi

2015-04-01

The March 11, 2011 Tohoku earthquake and its tsunami killed 18,508 people, including the missing (National Police Agency report as of April 2014) and raise the Level 7 accident at TEPCO's Fukushima Dai-ichi nuclear power station in Japan. The problems revealed can be viewed as due to a combination of risk-management, risk-communication, and geoethics issues. Japan's preparations for earthquakes and tsunamis are based on the magnitude of the anticipated earthquake for each region. The government organization coordinating the estimation of anticipated earthquakes is the "Headquarters for Earthquake Research Promotion" (HERP), which is under the Ministry of Education, Culture, Sports, Science and Technology (MEXT). Japan's disaster mitigation system is depicted schematically as consisting of three layers: seismology, civil engineering, and disaster mitigation planning. This research explains students in geoscience should study geoethics as part of their education related Tohoku earthquake and the Level 7 accident at TEPCO's Fukushima Dai-ichi nuclear power station. Only when they become practicing professionals, they will be faced with real geoethical dilemmas. A crisis such as the 2011 earthquake, tsunami, and Fukushima Dai-ichi nuclear accident, will force many geoscientists to suddenly confront previously unanticipated geoethics and risk-communication issues. One hopes that previous training will help them to make appropriate decisions under stress. We name it "decision science".

Implementation of the TsunamiReady Supporter Program in Puerto Rico

NASA Astrophysics Data System (ADS)

Flores Hots, V. E.; Vanacore, E. A.; Gonzalez Ruiz, W.; Gomez, G.

2016-12-01

The Puerto Rico Seismic Network (PRSN) manages the PR Tsunami Program (NTHMP), including the TsunamiReady Supporter Program. Through this program the PRSN helps private organizations, businesses, facilities or local government entities to willingly engage in tsunami planning and preparedness that meet some requirements established by the National Weather Service. TsunamiReady Supporter organizations are better prepared to respond to a tsunami emergency, developing a response plan (using a template that PRSN developed and provides), and reinforcing their communication systems including NOAA radio, RSS, and loud speakers to receive and disseminate the alerts issued by the NWS and the Tsunami Warning Centers (TWC). The planning and the communication systems added to the training that PRSN provides to the staff and employees, are intend to help visitors and employees evacuate the tsunami hazard zone to the nearest assembly point minimizing loss of life. Potential TsunamiReady Supporters include, but are not limited to, businesses, schools, churches, hospitals, malls, utilities, museums, beaches, and harbors. However, the traditional targets for such programs are primarily tourism sites and hotels where people unaware of the tsunami hazard may be present. In 2016 the Tsunami Ready Program guided four businesses to achieve the TsunamiReady Supporter recognition. Two facilities were hotels near or inside the evacuation zone. The other facilities were the first and only health center and supermarket to be recognized in the United States and US territories. Based on the experience of preparing the health center and supermarket sites, here we present two case studies of how the TsunamiReady Supporter Program can be applied to non-traditional facilities as well as how the application of this program to such facilities can improve tsunami hazard mitigation. Currently, we are working on expanding the application of this program to non-traditional facilities by working with a banking facility located in a tsunami evacuation zone increasing their capacity to manage a tsunami event and to reinforce the entity's involvement in developing a plan for their clients and employees to evacuate the area and head to a safe place.

Tohoku-Oki Earthquake Tsunami Runup and Inundation Data for Sites Around the Island of Hawaiʻi

USGS Publications Warehouse

Trusdell, Frank A.; Chadderton, Amy; Hinchliffe, Graham; Hara, Andrew; Patenge, Brent; Weber, Tom

2012-01-01

At 0546 U.t.c. March 11, 2011, a Mw 9.0 ("great") earthquake occurred near the northeast coast of Honshu Island, Japan, generating a large tsunami that devastated the east coast of Japan and impacted many far-flung coastal sites around the Pacific Basin. After the earthquake, the Pacific Tsunami Warning Center issued a tsunami alert for the State of Hawaii, followed by a tsunami-warning notice from the local State Civil Defense on March 10, 2011 (Japan is 19 hours ahead of Hawaii). After the waves passed the islands, U.S. Geological Survey (USGS) scientists from the Hawaiian Volcano Observatory (HVO) measured inundation (maximum inland distance of flooding), runup (elevation at maximum extent of inundation) and took photographs in coastal areas around the Island of Hawaiʻi. Although the damage in West Hawaiʻi is well documented, HVO's mapping revealed that East Hawaiʻi coastlines were also impacted by the tsunami. The intent of this report is to provide runup and inundation data for sites around the Island of Hawaiʻi.

The Global Tsunami Model (GTM)

NASA Astrophysics Data System (ADS)

Thio, H. K.; Løvholt, F.; Harbitz, C. B.; Polet, J.; Lorito, S.; Basili, R.; Volpe, M.; Romano, F.; Selva, J.; Piatanesi, A.; Davies, G.; Griffin, J.; Baptista, M. A.; Omira, R.; Babeyko, A. Y.; Power, W. L.; Salgado Gálvez, M.; Behrens, J.; Yalciner, A. C.; Kanoglu, U.; Pekcan, O.; Ross, S.; Parsons, T.; LeVeque, R. J.; Gonzalez, F. I.; Paris, R.; Shäfer, A.; Canals, M.; Fraser, S. A.; Wei, Y.; Weiss, R.; Zaniboni, F.; Papadopoulos, G. A.; Didenkulova, I.; Necmioglu, O.; Suppasri, A.; Lynett, P. J.; Mokhtari, M.; Sørensen, M.; von Hillebrandt-Andrade, C.; Aguirre Ayerbe, I.; Aniel-Quiroga, Í.; Guillas, S.; Macias, J.

2016-12-01

The large tsunami disasters of the last two decades have highlighted the need for a thorough understanding of the risk posed by relatively infrequent but disastrous tsunamis and the importance of a comprehensive and consistent methodology for quantifying the hazard. In the last few years, several methods for probabilistic tsunami hazard analysis have been developed and applied to different parts of the world. In an effort to coordinate and streamline these activities and make progress towards implementing the Sendai Framework of Disaster Risk Reduction (SFDRR) we have initiated a Global Tsunami Model (GTM) working group with the aim of i) enhancing our understanding of tsunami hazard and risk on a global scale and developing standards and guidelines for it, ii) providing a portfolio of validated tools for probabilistic tsunami hazard and risk assessment at a range of scales, and iii) developing a global tsunami hazard reference model. This GTM initiative has grown out of the tsunami component of the Global Assessment of Risk (GAR15), which has resulted in an initial global model of probabilistic tsunami hazard and risk. Started as an informal gathering of scientists interested in advancing tsunami hazard analysis, the GTM is currently in the process of being formalized through letters of interest from participating institutions. The initiative has now been endorsed by the United Nations International Strategy for Disaster Reduction (UNISDR) and the World Bank's Global Facility for Disaster Reduction and Recovery (GFDRR). We will provide an update on the state of the project and the overall technical framework, and discuss the technical issues that are currently being addressed, including earthquake source recurrence models, the use of aleatory variability and epistemic uncertainty, and preliminary results for a probabilistic global hazard assessment, which is an update of the model included in UNISDR GAR15.

The Global Tsunami Model (GTM)

NASA Astrophysics Data System (ADS)

Lorito, S.; Basili, R.; Harbitz, C. B.; Løvholt, F.; Polet, J.; Thio, H. K.

2017-12-01

The tsunamis occurred worldwide in the last two decades have highlighted the need for a thorough understanding of the risk posed by relatively infrequent but often disastrous tsunamis and the importance of a comprehensive and consistent methodology for quantifying the hazard. In the last few years, several methods for probabilistic tsunami hazard analysis have been developed and applied to different parts of the world. In an effort to coordinate and streamline these activities and make progress towards implementing the Sendai Framework of Disaster Risk Reduction (SFDRR) we have initiated a Global Tsunami Model (GTM) working group with the aim of i) enhancing our understanding of tsunami hazard and risk on a global scale and developing standards and guidelines for it, ii) providing a portfolio of validated tools for probabilistic tsunami hazard and risk assessment at a range of scales, and iii) developing a global tsunami hazard reference model. This GTM initiative has grown out of the tsunami component of the Global Assessment of Risk (GAR15), which has resulted in an initial global model of probabilistic tsunami hazard and risk. Started as an informal gathering of scientists interested in advancing tsunami hazard analysis, the GTM is currently in the process of being formalized through letters of interest from participating institutions. The initiative has now been endorsed by the United Nations International Strategy for Disaster Reduction (UNISDR) and the World Bank's Global Facility for Disaster Reduction and Recovery (GFDRR). We will provide an update on the state of the project and the overall technical framework, and discuss the technical issues that are currently being addressed, including earthquake source recurrence models, the use of aleatory variability and epistemic uncertainty, and preliminary results for a probabilistic global hazard assessment, which is an update of the model included in UNISDR GAR15.

The Global Tsunami Model (GTM)

NASA Astrophysics Data System (ADS)

Løvholt, Finn

2017-04-01

The large tsunami disasters of the last two decades have highlighted the need for a thorough understanding of the risk posed by relatively infrequent but disastrous tsunamis and the importance of a comprehensive and consistent methodology for quantifying the hazard. In the last few years, several methods for probabilistic tsunami hazard analysis have been developed and applied to different parts of the world. In an effort to coordinate and streamline these activities and make progress towards implementing the Sendai Framework of Disaster Risk Reduction (SFDRR) we have initiated a Global Tsunami Model (GTM) working group with the aim of i) enhancing our understanding of tsunami hazard and risk on a global scale and developing standards and guidelines for it, ii) providing a portfolio of validated tools for probabilistic tsunami hazard and risk assessment at a range of scales, and iii) developing a global tsunami hazard reference model. This GTM initiative has grown out of the tsunami component of the Global Assessment of Risk (GAR15), which has resulted in an initial global model of probabilistic tsunami hazard and risk. Started as an informal gathering of scientists interested in advancing tsunami hazard analysis, the GTM is currently in the process of being formalized through letters of interest from participating institutions. The initiative has now been endorsed by the United Nations International Strategy for Disaster Reduction (UNISDR) and the World Bank's Global Facility for Disaster Reduction and Recovery (GFDRR). We will provide an update on the state of the project and the overall technical framework, and discuss the technical issues that are currently being addressed, including earthquake source recurrence models, the use of aleatory variability and epistemic uncertainty, and preliminary results for a probabilistic global hazard assessment, which is an update of the model included in UNISDR GAR15.

Public Policy Issues Associated with Tsunami Hazard Mitigation, Response and Recovery: Transferable Lessons from Recent Global Disasters

NASA Astrophysics Data System (ADS)

Johnson, L.

2014-12-01

Since 2004, a sequence of devastating tsunamis has taken the lives of more than 300,000 people worldwide. The path of destruction left by each is typically measured in hundreds of meters to a few kilometers and its breadth can extend for hundreds even thousands of kilometers, crossing towns and countries and even traversing an entire oceanic basin. Tsunami disasters in Indonesia, Chile, Japan and elsewhere have also shown that the almost binary nature of tsunami impacts can present some unique risk reduction, response, recovery and rebuilding challenges, with transferable lessons to other tsunami vulnerable coastal communities around the world. In particular, the trauma can motivate survivors to relocate homes, jobs, and even whole communities to safer ground, sometimes at tremendous social and financial costs. For governments, the level of concentrated devastation usually exceeds the local capacity to respond and thus requires complex inter-governmental arrangements with regional, national and even international partners to support the recovery of impacted communities, infrastructure and economies. Two parallel projects underway in California since 2011—the SAFRR (Science Application for Risk Reduction) tsunami scenario project and the California Tsunami Policy Working Group (CTPWG)—have worked to digest key lessons from recent tsunami disasters, with an emphasis on identifying gaps to be addressed in the current state and federal policy framework to enhance tsunami risk awareness, hazard mitigation, and response and recovery planning ahead of disaster and also improve post-disaster implementation practices following a future California or U.S. tsunami event.

Rapid tsunami models and earthquake source parameters: Far-field and local applications

USGS Publications Warehouse

Geist, E.L.

2005-01-01

Rapid tsunami models have recently been developed to forecast far-field tsunami amplitudes from initial earthquake information (magnitude and hypocenter). Earthquake source parameters that directly affect tsunami generation as used in rapid tsunami models are examined, with particular attention to local versus far-field application of those models. First, validity of the assumption that the focal mechanism and type of faulting for tsunamigenic earthquakes is similar in a given region can be evaluated by measuring the seismic consistency of past events. Second, the assumption that slip occurs uniformly over an area of rupture will most often underestimate the amplitude and leading-wave steepness of the local tsunami. Third, sometimes large magnitude earthquakes will exhibit a high degree of spatial heterogeneity such that tsunami sources will be composed of distinct sub-events that can cause constructive and destructive interference in the wavefield away from the source. Using a stochastic source model, it is demonstrated that local tsunami amplitudes vary by as much as a factor of two or more, depending on the local bathymetry. If other earthquake source parameters such as focal depth or shear modulus are varied in addition to the slip distribution patterns, even greater uncertainty in local tsunami amplitude is expected for earthquakes of similar magnitude. Because of the short amount of time available to issue local warnings and because of the high degree of uncertainty associated with local, model-based forecasts as suggested by this study, direct wave height observations and a strong public education and preparedness program are critical for those regions near suspected tsunami sources.

The November 15, 2006 Kuril Islands-Generated Tsunami in Crescent City, California

NASA Astrophysics Data System (ADS)

Dengler, L.; Uslu, B.; Barberopoulou, A.; Yim, S. C.; Kelly, A.

2009-02-01

On November 15, 2006, Crescent City in Del Norte County, California was hit by a tsunami generated by a M w 8.3 earthquake in the central Kuril Islands. Strong currents that persisted over an eight-hour period damaged floating docks and several boats and caused an estimated 9.2 million in losses. Initial tsunami alert bulletins issued by the West Coast Alaska Tsunami Warning Center (WCATWC) in Palmer, Alaska were cancelled about three and a half hours after the earthquake, nearly five hours before the first surges reached Crescent City. The largest amplitude wave, 1.76-meter peak to trough, was the sixth cycle and arrived over two hours after the first wave. Strong currents estimated at over 10 knots, damaged or destroyed three docks and caused cracks in most of the remaining docks. As a result of the November 15 event, WCATWC changed the definition of Advisory from a region-wide alert bulletin meaning that a potential tsunami is 6 hours or further away to a localized alert that tsunami water heights may approach warning- level thresholds in specific, vulnerable locations like Crescent City. On January 13, 2007 a similar Kuril event occurred and hourly conferences between the warning center and regional weather forecasts were held with a considerable improvement in the flow of information to local coastal jurisdictions. The event highlighted the vulnerability of harbors from a relatively modest tsunami and underscored the need to improve public education regarding the duration of the tsunami hazards, improve dialog between tsunami warning centers and local jurisdictions, and better understand the currents produced by tsunamis in harbors.

Warning and prevention based on estimates with large uncertainties: the case of low-frequency and large-impact events like tsunamis

NASA Astrophysics Data System (ADS)

Tinti, Stefano; Armigliato, Alberto; Pagnoni, Gianluca; Zaniboni, Filippo

2013-04-01

Geoscientists deal often with hazardous processes like earthquakes, volcanic eruptions, tsunamis, hurricanes, etc., and their research is aimed not only to a better understanding of the physical processes, but also to provide assessment of the space and temporal evolution of a given individual event (i.e. to provide short-term prediction) and of the expected evolution of a group of events (i.e. to provide statistical estimates referred to a given return period, and a given geographical area). One of the main issues of any scientific method is how to cope with measurement errors, a topic which in case of forecast of ongoing or of future events translates into how to deal with forecast uncertainties. In general, the more data are available and processed to make a prediction, the more accurate the prediction is expected to be if the scientific approach is sound, and the smaller the associated uncertainties are. However, there are several important cases where assessment is to be made with insufficient data or insufficient time for processing, which leads to large uncertainties. Two examples can be given taken from tsunami science, since tsunamis are rare events that may have destructive power and very large impact. One example is the case of warning for a tsunami generated by a near-coast earthquake, which is an issue at the focus of the European funded project NearToWarn. Warning has to be launched before tsunami hits the coast, that is in a few minutes after its generation. This may imply that data collected in such a short time are not yet enough for an accurate evaluation, also because the implemented monitoring system (if any) could be inadequate (f.i. one reason of inadequacy could be that implementing a dense instrumental network could be judged too expensive for rare events) The second case is the long term prevention from tsunami strikes. Tsunami infrequency may imply that the historical record for a given piece of coast is too short to capture a statistical sufficient number of large tsunamis, which entails that tsunami hazard has to be estimated by means of speculated worst-case scenarios, and their consequences are evaluated accordingly and usually result associated with large uncertainty bands. In case of large uncertainties, the main issues for geoscientists are how to communicate the information (prediction and uncertainties) to stakeholders and citizens and how to build and implement together responsive procedures that should be adequate. Usually there is a tradeoff between the cost of the countermeasure (warning and prevention) and its efficacy (i.e. its capability of minimizing the damage). The level of the acceptable tradeoff is an issue pertaining to decision makers and to local threatened communities. This paper, that represents a contribution from the European project TRIDEC on management of emergency crises, discusses the role of geoscientists in providing predictions and the related uncertainties. It is stressed that through academic education geoscientists are formed more to better their understanding of processes and the quantification of uncertainties, but are often unprepared to communicate their results in a way appropriate for society. Filling this gap is crucial for improving the way geoscience and society handle natural hazards and devise proper defense means.

Contribution of Asteroid Generated Tsunami to the Impact Hazard

NASA Technical Reports Server (NTRS)

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.

Development and Application of a Message Metric for NOAA NWS Tsunami Warnings and Recommended Guidelines for the NWS TsunamiReady Program

NASA Astrophysics Data System (ADS)

Gregg, C. E.; Johnston, D. M.; Ricthie, L.; Meinhold, S.; Johnson, V.; Scott, C.; Farnham, C.; Houghton, B. F.; Horan, J.; Gill, D.

2012-12-01

Improving the quality and effectiveness of tsunami warning messages and the TsunamiReady community preparedness program of the US National Oceanic and Atmospheric Administration, National Weather Service's (NWS), Tsunami Program are two key objectives of a three year project (Award NA10NWS4670015) to help integrate social science into the NWS' Tsunami Program and improve the preparedness of member states and territories of the National Tsunami Hazard Mitigation Program (NTHMP). Research was conducted in collaboration with state and local emergency managers. Based on findings from focus group meetings with a purposive sample of local, state and Federal stakeholders and emergency managers in six states (AK, WA, OR, CA, HI and NC) and two US Territories (US Virgin Islands and American Samoa), and upon review of research literature on behavioral response to warnings, we developed a warning message metric to help guide revisions to tsunami warning messages issued by the NWS' West Coast/Alaska Tsunami Warning Center, Alaska and Pacific Tsunami Warning Center, Hawaii. The metric incorporates factors that predict response to warning information, which are divided into categories of Message Content, Style, Order and Formatting and Receiver Characteristics. A message is evaluated by cross-referencing the message with the meaning of metric factors and assigning a maximum score of one point per factor. Findings are then used to guide revisions of the message until the characteristics of each factor are met. From focus groups that gathered information on the usefulness and achievability of tsunami preparedness actions, we developed recommendations for revisions to the proposed draft guidelines of the TsunamiReady Improvement Program. Proposed key revisions include the incorporation of community vulnerability to distant (far-field) versus local (near-field) tsunamis as a primary determinant of mandatory actions, rather than community population. Our team continues to work with NWS personnel, including a NWS Tsunami Warning Improvement Team, and the focus group participants to finalize and pilot test prototype warning products and the draft TsunamiReady guidelines.

Streamlining Tsunami Messages (e.g., Warnings) of the US National Tsunami Warning Center, Palmer, Alaska

NASA Astrophysics Data System (ADS)

Gregg, C. E.; Sorensen, J. H.; Vogt Sorensen, B.; Whitmore, P.; Johnston, D. M.

2016-12-01

Spurred in part by world-wide interest in improving warning messaging for and response to tsunamis in the wake of several catastrophic tsunamis since 2004 and growing interest at the US National Weather Service (NWS) to integrate social science into their Tsunami Program, the NWS Tsunami Warning Centers in Alaska and Hawaii have made great progress toward enhancing tsunami messages. These include numerous products, among them being Tsunami Warnings, Tsunami Advisories and Tsunami Watches. Beginning in 2010 we have worked with US National Tsunami Hazard Mitigation Program (NTHMP) Warning Coordination and Mitigation and Education Subcommittee members; Tsunami Program administrators; and NWS Weather Forecast Officers to conduct a series of focus group meetings with stakeholders in coastal areas of Alaska, American Samoa, California, Hawaii, North Carolina, Oregon, US Virgin Islands and Washington to understand end-user perceptions of existing messages and their existing needs in message products. We also reviewed research literature on behavioral response to warnings to develop a Tsunami Warning Message Metric that could be used to guide revisions to tsunami warning messages of both warning centers. The message metric is divided into categories of Message Content, Style, Order, Formatting, and Receiver Characteristics. A sample message is evaluated by cross-referencing the message with the operational definitions of metric factors. Findings are then used to guide revisions of the message until the characteristics of each factor are met, whether the message is a full length or short message. Incrementally, this work contributed to revisions in the format, content and style of message products issued by the National Tsunami Warning Center (NTWC). Since that time, interest in short warning messages has continued to increase and in May 2016 the NTWC began efforts to revise message products to take advantage of recent NWS policy changes allowing use of mixed-case text format and expanded punctuation, a practice which the NWS first started in 2010. Here we describe our application of a modification of the warning message metric to develop new streamlined messages using mixed-case text. These messages reflect current state-of-the-art knowledge on warning message effectiveness.

Hydraulic experiment on formation mechanism of tsunami deposit and verification of sediment transport model for tsunamis

NASA Astrophysics Data System (ADS)

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 observation of velocity in Kesennnuma bay had a low accuracy. On the other hand, this hydraulic experiment measured accurate velocity and sand deposition distribution of various condition. Based on these data, we tried more accurate verification of the model of Takahashi et al. (1999).

New Science Applications Within the U.S. National Tsunami Hazard Mitigation Program

NASA Astrophysics Data System (ADS)

Wilson, R. I.; Eble, M. C.; Forson, C. K.; Horrillo, J. J.; Nicolsky, D.

2017-12-01

The U.S. National Tsunami Hazard Mitigation Program (NTHMP) is a collaborative State and Federal program which supports consistent and cost effective tsunami preparedness and mitigation activities at a community level. The NTHMP is developing a new five-year Strategic Plan based on the 2017 Tsunami Warning, Education, and Research Act as well as recommendations the 2017 NTHMP External Review Panel. Many NTHMP activities are based on the best available scientific methods through the NTHMP Mapping and Modeling Subcommittee (MMS). The primary activities for the MMS member States are to characterize significant tsunami sources, numerically model those sources, and create tsunami inundation maps for evacuation planning. This work remains a focus for many unmapped coastlines. With the lessons learned from the 2004 Indian Ocean and 2011 Tohoku Japan tsunamis, where both immediate risks and long-term recovery issues where recognized, the NTHMP MMS is expanding efforts into other areas that address community resilience. Tsunami evacuation modeling based on both pedestrian and vehicular modes of transportation are being developed by NTHMP States. Products include tools for the public to create personal evacuation maps. New tsunami response planning tools are being developed for both maritime and coastal communities. Maritime planning includes tsunami current-hazard maps for in-harbor and offshore response activities. Multi-tiered tsunami evacuation plans are being developed in some states to address local- versus distant-source tsunamis, as well as real-time evacuation plans, or "playbooks," for distant-source tsunamis forecasted to be less than the worst-case flood event. Products to assist community mitigation and recovery are being developed at a State level. Harbor Improvement Reports, which evaluate the impacts of currents, sediment, and debris on harbor infrastructure, include direct mitigation activities for Local Hazard Mitigation Plans. Building code updates in the five Pacific states will include new sections on tsunami load analysis of structures, and require Tsunami Design Zones based on probabilistic analyses. Guidance for community recovery planning has also been initiated. These new projects are being piloted by some States and will help create guidance for other States in the future.

Prioritizing earthquake and tsunami alerting efforts

NASA Astrophysics Data System (ADS)

Allen, R. M.; Allen, S.; Aranha, M. A.; Chung, A. I.; Hellweg, M.; Henson, I. H.; Melgar, D.; Neuhauser, D. S.; Nof, R. N.; Strauss, J. A.

2015-12-01

The timeline of hazards associated with earthquakes ranges from seconds for the strong shaking at the epicenter, to minutes for strong shaking at more distant locations in big quakes, to tens of minutes for a local tsunami. Earthquake and tsunami warning systems must therefore include very fast initial alerts, while also taking advantage of available time in bigger and tsunami-generating quakes. At the UC Berkeley Seismological Laboratory we are developing a suite of algorithms to provide the fullest possible information about earthquake shaking and tsunami inundation from seconds to minutes after a quake. The E-larmS algorithm uses the P-wave to rapidly detect an earthquake and issue a warning. It is currently issuing alerts to test users in as little as 3 sec after the origin time. Development of a new waveform detector may lead to even faster alerts. G-larmS uses permanent deformation estimates from GNSS stations to estimate the geometry and extent of rupture underway providing more accurate ground shaking estimates in big (M>~7) earthquakes. It performed well in the M6.0 2014 Napa earthquake. T-larmS is a new algorithm designed to extend alert capabilities to tsunami inundation. Rapid estimates of source characteristics for subduction zones event can not only be used to warn of the shaking hazard, but also the local tsunami inundation hazard. These algorithms are being developed, implemented and tested with a focus on the western US, but are also now being tested in other parts of the world including Israel, Turkey, Korea and Chile. Beta users in the Bay Area are receiving the alerts and beginning to implement automated actions. They also provide feedback on users needs, which has led to the development of the MyEEW smartphone app. This app allows beta users to receive the alerts on their cell phones. All these efforts feed into our ongoing assessment of directions and priorities for future development and implementation efforts.

Issues and Advances in Understanding Landslide-Generated Tsunamis: Toward a Unified Model

NASA Astrophysics Data System (ADS)

Geist, E. L.; Locat, J.; Lee, H. J.; Lynett, P. J.; Parsons, T.; Kayen, R. E.; Hart, P. E.

2008-12-01

The physics of tsunamis generated from submarine landslides is highly complex, involving a cross- disciplinary exchange in geophysics. In the 10 years following the devastating Papua New Guinea tsunami, there have been significant advances in understanding landslide-generated tsunamis. However, persistent issues still remain related to submarine landslide dynamics that may be addressed with collection of new marine geologic and geophysical observations. We review critical elements of landslide tsunamis in the hope of developing a unified model that encompasses all stages of the process from triggering to tsunami runup. Because the majority of non-volcanogenic landslides that generate tsunamis are triggered seismically, advances in understanding inertial displacements and changes in strength and rheologic properties in response to strong-ground motion need to be included in a unified model. For example, interaction between compliant marine sediments and multi-direction ground motion results in greater permanent plastic displacements than predicted by traditional rigid-block analysis. When considering the coupling of the overlying water layer in the generation of tsunamis, the post-failure dynamics of landslides is important since the overall rate of seafloor deformation for landslides is less than or comparable to the phase speed of tsunami waves. As such, the rheologic and mechanical behavior of the slide material needs to be well understood. For clayey and silty debris flows, a non-linear (Herschel-Bulkley) and bilinear rheology have recently been developed to explain observed runout distances and deposit thicknesses. An additional complexity to this rheology is the inclusion of hydrate-laden sediment that commonly occurs along continental slopes. Although it has been proposed in the past that gas hydrate dissociation may provide potential failure planes for slide movement, it is unclear how zones of rigid hydrate-bearing sediment surrounded by a more viscoplastic 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.

The seismic project of the National Tsunami Hazard Mitigation Program

USGS Publications Warehouse

Oppenheimer, D.H.; Bittenbinder, A.N.; Bogaert, B.M.; Buland, R.P.; Dietz, L.D.; Hansen, R.A.; Malone, S.D.; McCreery, C.S.; Sokolowski, T.J.; Whitmore, P.M.; Weaver, C.S.

2005-01-01

In 1997, the Federal Emergency Management Agency (FEMA), National Oceanic and Atmospheric Administration (NOAA), U.S. Geological Survey (USGS), and the five western States of Alaska, California, Hawaii, Oregon, and Washington joined in a partnership called the National Tsunami Hazard Mitigation Program (NTHMP) to enhance the quality and quantity of seismic data provided to the NOAA tsunami warning centers in Alaska and Hawaii. The NTHMP funded a seismic project that now provides the warning centers with real-time seismic data over dedicated communication links and the Internet from regional seismic networks monitoring earthquakes in the five western states, the U.S. National Seismic Network in Colorado, and from domestic and global seismic stations operated by other agencies. The goal of the project is to reduce the time needed to issue a tsunami warning by providing the warning centers with high-dynamic range, broadband waveforms in near real time. An additional goal is to reduce the likelihood of issuing false tsunami warnings by rapidly providing to the warning centers parametric information on earthquakes that could indicate their tsunamigenic potential, such as hypocenters, magnitudes, moment tensors, and shake distribution maps. New or upgraded field instrumentation was installed over a 5-year period at 53 seismic stations in the five western states. Data from these instruments has been integrated into the seismic network utilizing Earthworm software. This network has significantly reduced the time needed to respond to teleseismic and regional earthquakes. Notably, the West Coast/Alaska Tsunami Warning Center responded to the 28 February 2001 Mw 6.8 Nisqually earthquake beneath Olympia, Washington within 2 minutes compared to an average response time of over 10 minutes for the previous 18 years. ?? Springer 2005.

Trajectory analysis of Polar Patrol Balloon (PPB) flights in the stratosphere over Antarctica in summer and spring: A preliminary result

NASA Technical Reports Server (NTRS)

Kanzawa, Hiroshi; Fujii, Ryoichi; Yamazaki, Koji; Yamanaka, Manabu D.

1994-01-01

Actual trajectories of two PPB's which flew in the Antarctic stratosphere in austral summer and spring are compared with those calculated based on objective analysis data of Japan Meteorological Agency (JMA). The differences between the actual and calculated trajectories are discussed to check reliability of the JMA objective analysis data for the stratosphere, and to detect subsynoptic scale variability due to gravity waves and others.

Operational Tsunami Modelling with TsunAWI for the German-Indonesian Tsunami Early Warning System: Recent Developments

NASA Astrophysics Data System (ADS)

Rakowsky, N.; Harig, S.; Androsov, A.; Fuchs, A.; Immerz, A.; Schröter, J.; Hiller, W.

2012-04-01

Starting in 2005, the GITEWS project (German-Indonesian Tsunami Early Warning System) established from scratch a fully operational tsunami warning system at BMKG in Jakarta. Numerical simulations of prototypic tsunami scenarios play a decisive role in a priori risk assessment for coastal regions and in the early warning process itself. Repositories with currently 3470 regional tsunami scenarios for GITEWS and 1780 Indian Ocean wide scenarios in support of Indonesia as a Regional Tsunami Service Provider (RTSP) were computed with the non-linear shallow water modell TsunAWI. It is based on a finite element discretisation, employs unstructured grids with high resolution along the coast and includes inundation. This contribution gives an overview on the model itself, the enhancement of the model physics, and the experiences gained during the process of establishing an operational code suited for thousands of model runs. Technical aspects like computation time, disk space needed for each scenario in the repository, or post processing techniques have a much larger impact than they had in the beginning when TsunAWI started as a research code. Of course, careful testing on artificial benchmarks and real events remains essential, but furthermore, quality control for the large number of scenarios becomes an important issue.

Implementation of the NEAMTWS in Portugal

NASA Astrophysics Data System (ADS)

Matias, L. M.; Annunziato, A.; Carrilho, F.; Baptista, M.

2008-12-01

In this paper we present the ongoing implementation of a national tsunami warning system in Portugal. After the Sumatra event in December 2004, the UNESCO, through its International Oceanographic Commission, recognized the need for an end to end global tsunami warning system and International Coordination Groups have been established for different areas around the globe: Indian, Caribbean, Atlantic and Mediterranean ocean basins. This system is the natural response to the historical and recent instrumental events generated along the western segment of the Eurasia and Nubian plates, which eastern end corresponds to the Gulf of Cadiz. The TWS includes three main components: the seismic detection, the tsunami detection and the issue of warnings/alerts. In Portugal the automatic earthquake processing is installed at IM (Instituto de Meteorologia) which is the only national institution operating on a 24x7 basis. This makes IM the natural candidate to host the Portuguese tsunami warning system. The TWS under implementation has several key points: definition of the tsunami scenarios, tsunami detection, and tsunami protocol messages. The system will also be able to predict tsunami potential impact along the coast, wave-heights and arrival times at pre-defined locations along the coast. In this study we present the recent results on definition of tsunami scenarios, establishment of the scenario database and the tsunami analysis tool. This work is a joint effort between Instituto de Meteorologia (Portugal), the Joint Research Center, JRC- ISPRA, Italy and the coordination of the Portuguese Group for the implementation of NEAMTWS in the area. This work has been financed by different European projects as NEAREST and TRANSFER, and also by the JRC, the IM and CGUL/IDL institutions.

A new GIS-based tsunami risk evaluation: MeTHuVA (METU tsunami human vulnerability assessment) at Yenikapı, Istanbul

NASA Astrophysics Data System (ADS)

Cankaya, Zeynep Ceren; Suzen, Mehmet Lutfi; Yalciner, Ahmet Cevdet; Kolat, Cagil; Zaytsev, Andrey; Aytore, Betul

2016-07-01

Istanbul is a mega city with various coastal utilities located on the northern coast of the Sea of Marmara. At Yenikapı, there are critical vulnerable coastal utilities, structures, and active metropolitan life. Fishery ports, commercial ports, small craft harbors, passenger terminals of intercity maritime transportation, waterfront commercial and/or recreational structures with residential/commercial areas and public utility areas are some examples of coastal utilization that are vulnerable to marine disasters. Therefore, the tsunami risk in the Yenikapı region is an important issue for Istanbul. In this study, a new methodology for tsunami vulnerability assessment for areas susceptible to tsunami is proposed, in which the Yenikapı region is chosen as a case study. Available datasets from the Istanbul Metropolitan Municipality and Turkish Navy are used as inputs for high-resolution GIS-based multi-criteria decision analysis (MCDA) evaluation of tsunami risk in Yenikapı. Bathymetry and topography database is used for high-resolution tsunami numerical modeling where the tsunami hazard, in terms of coastal inundation, is deterministically computed using the NAMI DANCE numerical code, considering earthquake worst case scenarios. In order to define the tsunami human vulnerability of the region, two different aspects, vulnerability at location and evacuation resilience maps were created using the analytical hierarchical process (AHP) method of MCDA. A vulnerability at location map is composed of metropolitan use, geology, elevation, and distance from shoreline layers, whereas an evacuation resilience map is formed by slope, distance within flat areas, distance to buildings, and distance to road networks layers. The tsunami risk map is then computed by the proposed new relationship which uses flow depth maps, vulnerability at location maps, and evacuation resilience maps.

Implementation of a Global Navigation Satellite System (GNSS) Augmentation to Tsunami Early Warning Systems

NASA Astrophysics Data System (ADS)

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 Participation.

Dynamic Tsunami Data Assimilation (DTDA) Based on Green's Function: Theory and Application

NASA Astrophysics Data System (ADS)

Wang, Y.; Satake, K.; Gusman, A. R.; Maeda, T.

2017-12-01

Tsunami data assimilation estimates the tsunami arrival time and height at Points of Interest (PoIs) by assimilating tsunami data observed offshore into a numerical simulation, without the need of calculating initial sea surface height at the source (Maeda et al., 2015). The previous tsunami data assimilation has two main problems: one is that it requires quite large calculating time because the tsunami wavefield of the whole interested region is computed continuously; another is that it relies on dense observation network such as Dense Oceanfloor Network system for Earthquakes and Tsunamis (DONET) in Japan or Cascadia Initiative (CI) in North America (Gusman et al., 2016), which is not practical for some area. Here we propose a new approach based on Green's function to speed up the tsunami data assimilation process and to solve the problem of sparse observation: Dynamic Tsunami Data Assimilation (DTDA). If the residual between the observed and calculated tsunami height is not zero, there will be an assimilation response around the station, usually a Gaussian-distributed sea surface displacement. The Green's function Gi,j is defined as the tsunami waveform at j-th grid caused by the propagation of assimilation response at i-th station. Hence, the forecasted waveforms at PoIs are calculated as the superposition of the Green's functions. In case of sparse observation, we could use the aircraft and satellite observations. The previous assimilation approach is not practical because it costs much time to assimilate moving observation, and to compute the tsunami wavefield of the interested region. In contrast, DTDA synthesizes the waveforms quickly as long as the Green's functions are calculated in advance. We apply our method to a hypothetic earthquake off the west coast of Sumatra Island similar to the 2004 Indian Ocean earthquake. Currently there is no dense observation network in that area, making it difficult for the previous assimilation approach. We used DTDA with aircraft and satellite observation above the Indian Ocean, to forecast the tsunami in Sri Lanka, India and Thailand. It shows that DTDA provides reliable tsunami forecasting for these countries, and the tsunami early warning can be issued half an hour before the tsunami arrives to reduce the damage along the coast.

Challenges of Tsunami Disaster and Extreme climate Events Along Coastal Region in Asia-Pacific

NASA Astrophysics Data System (ADS)

Chaudhari, S.

2017-12-01

South Asia is more vulnerable to Geo disasters and impacts of climate changes in recent years. On 26 December 2004 massive waves triggered by an earthquake surged into coastal communities in Asia and East Africa with devastating force. Hitting Indonesia, Sri Lanka , Thailand and India hardest, the deadly waves swept more than 200 000 people to their deaths. Also in an another extreme climate change phenomenon during 2005 - 2006,causing heavy rains and flooding situation in the South Asia - Europe and Pacific region ,more than 100 million population in these regions are witnessing the social- economical and ecological risks and impacts due to climate changes and Geohazards. For mitigating geo-disasters, marine hazards and rehabilitation during post tsunami period, scientific knowledge is needed, requiring experienced research communities who can train the local population during tsunami rehabilitation. Several civil society institutions jointly started the initiatives on the problem identifications in management of risks in geo-disasters, tsunami rehabilitation ,Vulnerability and risk assessments for Geohazards etc., to investigate problems related to social-economic and ecological risks and management issues resulting from the December tsunami and Geo- disaster, to aid mitigation planning in affected areas and to educate scientists and local populations to form a basis for sustainable and economic solutions. The poster aims to assess the potential risk and hazard , technical issues, problems and damage arising from Tsunami in the Asia-pacific region in coastal geology, coastal ecosystems and coastal environmental systems . This poster deals with the status and issues of interactions between Human and Ocean Systems, Geo-risks, marine risks along coastal region of Asia- Pacific and also human influence on the earth system . The poster presentation focuses on capacity building of the local population, scientists and researchers for integration of human and ocean systems through Geohazards Studies on vulnerability and risk assessments along coastal regions. The poster presentation also focuses on building natural -social science research community for sustainable solutions adoptions and mitigations of impacts of extreme climate events on environment and ecosystems along coastal region.

Tsunami Hockey

NASA Astrophysics Data System (ADS)

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 minute simulated time steps takes approximately 50 minutes on the same system. These animations are generated quickly enough to provide decision support for emergency managers whose coastlines may be impacted by the tsunami several hours later. Tsunami reflections can also aid in determining the source region for those tsunamis generated by non-seismic mechanisms without a clear source such as meteotsunamis, tsunamis generated by meteorological phenomena. A derecho that crossed the New Jersey coast and entered the Atlantic Ocean at approximately 1500 UTC June 13, 2013 generated a meteotsunami that struck the northeast coast of the US causing several injuries. A DART sensor off Montauk, NY, recorded tsunami waves approximately 200 minutes apart. We show how the arrival times of the tsunamis recorded by this DART can help to constrain the source region of the meteotsunami. We also examine other reflections produced by the Haida Gwaii 2012, Tohoku 2011, and other tsunamis.

Physical Observations of the Tsunami during the September 8th 2017 Tehuantepec, Mexico Earthquake

NASA Astrophysics Data System (ADS)

Ramirez-Herrera, M. T.; Corona, N.; Ruiz-Angulo, A.; Melgar, D.; Zavala-Hidalgo, J.

2017-12-01

The September 8th 2017, Mw8.2 earthquake offshore Chiapas, Mexico, is the largest earthquake recorded history in Chiapas since 1902. It caused damage in the states of Oaxaca, Chiapas and Tabasco; it had more than 100 fatalities, over 1.5 million people were affected, and 41,000 homes were damaged in the state of Chiapas alone. This earthquake, a deep intraplate event on a normal fault on the oceanic subducting plate, generated a tsunami recorded at several tide gauge stations in Mexico and on the Pacific Ocean. Here we report the physical effects of the tsunami on the Chiapas coast and analyze the societal implications of this tsunami on the basis of our field observations. Tide gauge data indicate 11.3 and 8.2 cm of coastal subsidence at Salina Cruz and Puerto Chiapas stations. The associated tsunami waves were recorded first at Salina Cruz tide gauge station at 5:13 (GMT). We covered ground observations along 41 km of the coast of Chiapas, encompassing the sites with the highest projected wave heights based on the preliminary tsunami model (maximum tsunami amplitudes between -94.5 and -93.0 W). Runup and inundation distances were measured with an RTK GPS and using a Sokkia B40 level along 8 sites. We corrected runup data with estimated astronomical tide levels at the time of the tsunami. The tsunami occurred at low tide. The maximum runup was 3 m at Boca del Cielo, and maximum inundation distance was 190 m in Puerto Arista, corresponding to the coast directly opposite the epicenter and in the central sector of the Gulf of Tehuantepec. In general, our field data agree with the predicted results from the preliminary tsunami model. Tsunami scour and erosion was evident on the Chiapas coast. Tsunami deposits, mainly sand, reached up to 32 cm thickness thinning landwards up to 172 m distance. Even though the Mexican tsunami early warning system (CAT) issued several warnings, the tsunami arrival struck the Chiapas coast prior to the arrival of official warnings to the residents of small coastal towns, owing to the multi-ranked notification system. Thus, a tsunami early warning system with a direct warning to all coastal communities is needed. Some people evacuated under their own initiative, but some did not evacuate. Therefore, community-based education and awareness programs are needed.

SCALE TSUNAMI Analysis of Critical Experiments for Validation of 233U Systems

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mueller, Don; Rearden, Bradley T

2009-01-01

Oak Ridge National Laboratory (ORNL) staff used the SCALE TSUNAMI tools to provide a demonstration evaluation of critical experiments considered for use in validation of current and anticipated operations involving {sup 233}U at the Radiochemical Development Facility (RDF). This work was reported in ORNL/TM-2008/196 issued in January 2009. This paper presents the analysis of two representative safety analysis models provided by RDF staff.

Using Media in the Classroom: Learning and Teaching about the 2011 Japanese Earth-Quake, Tsunami and Nuclear Events from a Socio-Scientific and Science Literacy Perspective

ERIC Educational Resources Information Center

Van Rooy, Wilhelmina; Moore, Leah

2012-01-01

This article discusses using students' analysis of media coverage of the March 2011 Japanese earthquake, tsunami and nuclear events to develop their knowledge and understanding of geological concepts and related socio-scientific issues. It draws on news reported at that time, identifies themes in those reports, and suggests how this event can be…

Educating and Preparing for Tsunamis in the Caribbean

NASA Astrophysics Data System (ADS)

von Hillebrandt-Andrade, C.; Aliaga, B.; Edwards, S.

2013-12-01

The Caribbean and Adjacent Regions has a long history of tsunamis and earthquakes. Over the past 500 years, more than 75 tsunamis have been documented in the region by the NOAA National Geophysical Data Center. Just since 1842, 3446 lives have been lost to tsunamis; this is more than in the Northeastern Pacific for the same time period. With a population of almost 160 million, over 40 million visitors a year and a heavy concentration of residents, tourists, businesses and critical infrastructure along its shores (especially in the northern and eastern Caribbean), the risk to lives and livelihoods is greater than ever before. The only way to survive a tsunami is to get out of harm's way before the waves strike. In the Caribbean given the relatively short distances from faults, potential submarine landslides and volcanoes to some of the coastlines, the tsunamis are likely to be short fused, so it is imperative that tsunami warnings be issued extremely quickly and people be educated on how to recognize and respond. Nevertheless, given that tsunamis occur infrequently as compared with hurricanes, it is a challenge for them to receive the priority they require in order to save lives when the next one strikes the region. Close cooperation among countries and territories is required for warning, but also for education and public awareness. Geographical vicinity and spoken languages need to be factored in when developing tsunami preparedness in the Caribbean, to make sure citizens receive a clear, reliable and sound science based message about the hazard and the risk. In 2006, in the wake of the Indian Ocean tsunami and after advocating without success for a Caribbean Tsunami Warning System since the mid 90's, the Intergovernmental Oceanographic Commission of UNESCO established the Intergovernmental Coordination Group for the Tsunami and other Coastal Hazards Warning System for the Caribbean and Adjacent Regions (CARIBE EWS). Its purpose is to advance an end to end tsunami warning system that serves regionally and delivers locally, saving lives and livelihoods, not only from tsunamis, but all coastal hazards. Through this and other platforms, physical and social scientists, emergency managers and elected officials have been working together via different mechanisms. Community based recognition programs, like the TsunamiReadyTM Program, regional tsunami exercises, sub-regional public education activities such as the Tsunami Smart campaigns, internet technologies, social media, meetings and conferences, identification of local and national champions, capitalization of news breaking tsunamis and earthquakes, economic resources for equipment and training have all been key to developing a tsunami safer Caribbean. Given these efforts, according to a 2013 survey, 93% of the countries covered by CARIBE EWS have tsunami response protocols in place, although much more work is required. In 2010 the US National Weather Service established the Caribbean Tsunami Warning Program as the first step towards a Caribbean Tsunami Warning Center in the region. In 2013 the Caribbean Tsunami Information Center was established in Barbados. Both these institutions which serve the region play a key role for promoting both the warning and educational components of the warning system.

Combining historical eyewitness accounts on tsunami-induced waves and numerical simulations for getting insights in uncertainty of source parameters

NASA Astrophysics Data System (ADS)

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 and numerical simulations. In order to learn the uncertainty information on source parameters, we treat the problem within the Bayesian setting, which enables to incorporate in a flexible manner the different uncertainty sources. We propose to rely on an emerging technique called Approximate Bayesian Computation ABC, which has been developed to estimate the posterior distribution in modelling scenarios where the likelihood function is either unknown or cannot be explicitly defined. To overcome the computational issue, we combine ABC with statistical emulators (aka meta-model). We apply the proposed approach on the case study of Ligurian (North West of Italy) tsunami (1887) and discuss the results with a special attention paid to the impact of the observational error.

Tsunami Detection by High Frequency Radar Beyond the Continental Shelf: II. Extension of Time Correlation Algorithm and Validation on Realistic Case Studies

NASA Astrophysics Data System (ADS)

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 early tsunami detection possible with the TC-TDA. Based on these results, we discuss how the new algorithm could be combined with standard methods proposed earlier, based on a Doppler analysis, to develop a new tsunami detection system based on HF radar data, that could increase warning time. This will be the object of future work, which will be based on actual, rather than simulated, radar data.

Advanced Planning for Tsunamis in California

NASA Astrophysics Data System (ADS)

Miller, K.; Wilson, R. I.; Larkin, D.; Reade, S.; Carnathan, D.; Davis, M.; Nicolini, T.; Johnson, L.; Boldt, E.; Tardy, A.

2013-12-01

The California Tsunami Program is comprised of the California Governor's Office of Emergency Services (CalOES) and the California Geological Survey (CGS) and funded through the National Tsunami Hazard Mitigation Program (NTHMP) and the Federal Emergency Management Agency (FEMA). The program works closely with the 20 coastal counties in California, as well as academic, and industry experts to improve tsunami preparedness and mitigation in shoreline communities. Inundation maps depicting 'worst case' inundation modeled from plausible sources around the Pacific were released in 2009 and have provided a foundation for public evacuation and emergency response planning in California. Experience during recent tsunamis impacting the state (Japan 2011, Chile 2010, Samoa 2009) has brought to light the desire by emergency managers and decision makers for even more detailed information ahead of future tsunamis. A solution to provide enhanced information has been development of 'playbooks' to plan for a variety of expected tsunami scenarios. Elevation 'playbook' lines can be useful for partial tsunami evacuations when enough information about forecast amplitude and arrival times is available to coastal communities and there is sufficient time to make more educated decisions about who to evacuate for a given scenario or actual event. NOAA-issued Tsunami Alert Bulletins received in advance of a distant event will contain an expected wave height (a number) for each given section of coast. Provision of four elevation lines for possible inundation enables planning for different evacuation scenarios based on the above number potentially alleviating the need for an 'all or nothing' decision with regard to evacuation. Additionally an analytical tool called FASTER is being developed to integrate storm, tides, modeling errors, and local tsunami run-up potential with the forecasted tsunami amplitudes in real-time when a tsunami Alert is sent out. Both of these products will help communities better implement evacuations and response activities for minor to moderate (less than maximum) tsunami events. A working group comprised of federal, state, and local governmental scientists, emergency managers, first responders, and community planners has explored details and delivery of the above tools for incorporation into emergency management protocols. The eventual outcome will be inclusion in plans, testing of protocols and methods via drills and exercises and application, as appropriate, during an impending tsunami event.

Mental health in Aceh--Indonesia: A decade after the devastating tsunami 2004.

PubMed

Marthoenis, Marthoenis; Yessi, Sarifah; Aichberger, Marion C; Schouler-Ocak, Meryam

2016-02-01

The province of Aceh has suffered enormously from the perennial armed conflict and the devastating Tsunami in 2004. Despite the waves of external aid and national concern geared toward improving healthcare services as part of the reconstruction and rehabilitation efforts after the Tsunami, mental health services still require much attention. This paper aims to understand the mental healthcare system in Aceh Province, Indonesia; its main focus is on the burden, on the healthcare system, its development, service delivery and cultural issues from the devastating Tsunami in 2004 until the present. We reviewed those published and unpublished reports from the local and national government, from international instances (UN bodies, NGOs) and from the academic literature pertaining to mental health related programs conducted in Aceh. To some extent, mental health services in Aceh have been improved compared to their condition before the Tsunami. The development programs have focused on procurement of policy, improvement of human resources, and enhancing service delivery. Culture and religious beliefs shape the pathways by which people seek mental health treatment. The political system also determines the development of the mental health service in the province. The case of Aceh is a unique example where conflict and disaster serve as the catalysts toward the development of a mental healthcare system. Several factors contribute to the improvement of the mental health system, but security is a must. Whilst the Acehnese enjoy the improvements, some issues such as stigma, access to care and political fluctuations remain challenging. Copyright © 2016 Elsevier B.V. All rights reserved.

Far-field tsunami of 2017 Mw 8.1 Tehuantepec, Mexico earthquake recorded by Chilean tide gauge network: Implications for tsunami warning systems

NASA Astrophysics Data System (ADS)

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 tide gauge stations and compare them with recorded sea level data, to dismiss meteorological processes, such as storms and surges. Resonance analysis is performed by wavelet technique.

Effect of Variable Manning Coefficients on Tsunami Inundation

NASA Astrophysics Data System (ADS)

Barberopoulou, A.; Rees, D.

2017-12-01

Numerical simulations are commonly used to help estimate tsunami hazard, improve evacuation plans, issue or cancel tsunami warnings, inform forecasting and hazard assessments and have therefore become an integral part of hazard mitigation among the tsunami community. Many numerical codes exist for simulating tsunamis, most of which have undergone extensive benchmarking and testing. Tsunami hazard or risk assessments employ these codes following a deterministic or probabilistic approach. Depending on the scope these studies may or may not consider uncertainty in the numerical simulations, the effects of tides, variable friction or estimate financial losses, none of which are necessarily trivial. Distributed manning coefficients, the roughness coefficients used in hydraulic modeling, are commonly used in simulating both riverine and pluvial flood events however, their use in tsunami hazard assessments is primarily part of limited scope studies and for the most part, not a standard practice. For this work, we investigate variations in manning coefficients and their effects on tsunami inundation extent, pattern and financial loss. To assign manning coefficients we use land use maps that come from the New Zealand Land Cover Database (LCDB) and more recent data from the Ministry of the Environment. More than 40 classes covering different types of land use are combined into major classes such as cropland, grassland and wetland representing common types of land use in New Zealand, each of which is assigned a unique manning coefficient. By utilizing different data sources for variable manning coefficients, we examine the impact of data sources and classification methodology on the accuracy of model outputs.

Microwave heating of a high-Tc YBa2Cu3O6.9 superconductor through a Josephson-junction system

NASA Astrophysics Data System (ADS)

Stankowski, J.; Czyak, B.; Martinek, J.

1990-12-01

An overheating of a Josephson-junction system (JJS) in ceramic YBa2Cu3O6.9 samples was induced by microwave irradiation in a microwave cavity. The amplitude of the Josephson microwave absorption (JMA) was used as a monitor of the local JJS temperature. The difference between the JJS temperature and a sample temperature depends linearly on the power of the microwave field. A thermal hysteresis of Tc for heating and cooling is proportional to the microwave power applied in the JMA experiment.

Regional Impact of the 29 September 2009 North Tonga Tsunami on the Futuna and Alofi Islands (Wallis & Futuna)

NASA Astrophysics Data System (ADS)

Lamarche, G.; Pelletier, B.; Goff, J. R.

2009-12-01

The north Tonga earthquake occurred at 5:48am on 30 September local time in Futuna, ~650 km west of the epicentre. The PTWC issued a warning at 6:04am for tsunami arrival in Wallis (Wallis & Futuna) at 6.35am. No warning was issued by the territorial authorities for Wallis nor for Futuna, located 230 km to the south-west. There was no reported tsunami on Wallis. However a tsunami hit the archipelago of Futuna (islands of Futuna and Alofi) between 7.00 and 7.20am on 30 September. The tide was approximately 3/4 out. We took advantage of an 8 days survey funded by the French Ministry of Foreign Affairs, previously planned for investigating palaeotsunamis on Futuna and Alofi. We measured run-up and inundation from the mid- to low-tide mark, as well as flow depths, and sediments associated with the 30 September tsunami at 41 sites around the islands. Run-ups were estimated based on visual evidence of recent coastal impact - burnt grasses and plants, sand and other displaced debris (e.g., on the road). We interviewed the population on multiple occasions. The maximum run-up of 4.5 m was observed on the eastern beach of Alofitai in Alofi, associated with an inundation of 85 m and a flow depth of 3m at the coast. On Futuna, we measured maximum run-ups of 4.4 m on the eastern tip and 4.3 m on the NW tip of the island, with maximum inundations of 95 and 72m, respectively. A flow depth of 2 m was inferred on the NE tip. Overall, the tsunami impact was more severe on the northern coast of Futuna, with run-ups ranging from 2.1 to 4.3 m. Very small run-ups and inundations were observed along the southern coast, with a 1.0 m run-up and 10 m inundation measured in Léava, the capital of Futuna. Most witnesses report two main waves equivalent in amplitude, the second one being sometimes described as the largest. All witnesses indicate that the sea withdrew first. A video suggests only a few minutes between the successive waves (likely not the first) in Léava. The video shows the reef exposed well below the lowest tides. There were no casualties. One inhabitant was warned by LCI television at 06:30am and was able to witness the tsunami. There were unconfirmed reports of two women taken by surprise by the arrival of the tsunami on the reef near the eastern end of Futuna, but who managed to hold on to trees to avoid being taken out to sea by the backwash. A significant disaster was avoided essentially because it was early and the tide was low when the tsunami hit. Such an event at high tide would have added about 0.8-1m in height to the wave and have undoubtedly resulted in severe damage, injuries and possibly deaths. This event, together with a small tsunami triggered by a Mw 6.4 local earthquake in March 1993 and an oral legend about a deadly and destructive wave indicate that the tsunami risk for Futuna is high for the >4000 inhabitants who live almost exclusively on a 50-400 m-wide coastal strip, between a narrow reef and landward coastal cliffs. However, the hour and 10 minutes that the 30 September tsunami took to reach the island provided sufficient time to issue a warning to the population who can rapidly reach safety on this mountainous landscape.

Evidence-Based Support for the Characteristics of Tsunami Warning Messages for Local, Regional and Distant Sources

NASA Astrophysics Data System (ADS)

Gregg, C. E.; Johnston, D. M.; Sorensen, J. H.; Vogt Sorensen, B.; Whitmore, P.

2014-12-01

Many studies since 2004 have documented the dissemination and receipt of risk information for local to distant tsunamis and factors influencing people's responses. A few earlier tsunami studies and numerous studies of other hazards provide additional support for developing effective tsunami messages. This study explores evidence-based approaches to developing such messages for the Pacific and National Tsunami Warning Centers in the US. It extends a message metric developed for the NWS Tsunami Program. People at risk to tsunamis receive information from multiple sources through multiple channels. Sources are official and informal and environmental and social cues. Traditionally, official tsunami messages followed a linear dissemination path through relatively few channels from warning center to emergency management to public and media. However, the digital age has brought about a fundamental change in the dissemination and receipt of official and informal communications. Information is now disseminated in very non-linear paths and all end-user groups may receive the same message simultaneously. Research has demonstrated a range of factors that influence rapid respond to an initial real or perceived threat. Immediate response is less common than one involving delayed protective actions where people first engage in "milling behavior" to exchange information and confirm the warning before taking protective action. The most important message factors to achieve rapid response focus on the content and style of the message and the frequency of dissemination. Previously we developed a tsunami message metric consisting of 21 factors divided into message content and style and receiver characteristics. Initially, each factor was equally weighted to identify gaps, but here we extend the work by weighting specific factors. This utilizes recent research that identifies the most important determinants of protective action. We then discuss the prioritization of message information in the context of potentially limited space in evolving tsunami messages issued by the warning centers.

A contribution to the selection of tsunami human vulnerability indicators: conclusions from tsunami impacts in Sri Lanka and Thailand (2004), Samoa (2009), Chile (2010) and Japan (2011)

NASA Astrophysics Data System (ADS)

González-Riancho, P.; Aliaga, B.; Hettiarachchi, S.; González, M.; Medina, R.

2014-12-01

After several tsunami events with disastrous consequences around the world, coastal countries have realized the need to be prepared to minimize human mortality and damage to coastal infrastructures, livelihoods and resources. The international scientific community is striving to develop and validate methodologies for tsunami hazard and vulnerability and risk assessments. The vulnerability of coastal communities is usually assessed through the definition of sets of indicators based on previous literature and/or post-tsunami reports, as well as on the available data for the study site. The aim of this work is to validate in light of past tsunami events the indicators currently proposed by the scientific community to measure human vulnerability, to improve their definition and selection as well as to analyse their validity for different country development profiles. The events analyzed are the 2011 Great Tohoku tsunami, the 2010 Chilean tsunami, the 2009 Samoan tsunami and the 2004 Indian Ocean tsunami. The results obtained highlight the need for considering both permanent and temporal human exposure, the former requiring some hazard numerical modelling while the latter is related to site-specific livelihoods, cultural traditions and gender roles. The most vulnerable age groups are the elderly adults and the children, the former having much higher mortality rates. Female mortality is not always higher than male and not always related to dependency issues. Higher numbers of disabled people do not always translate into higher numbers of victims. Besides, it is clear that mortality is not only related to the characteristics of the population but also the buildings. A high correlation has been found between the affected buildings and the number of victims, being very high for completely damaged buildings. Distance to the sea, building materials and expected water depths are highly determining factors regarding the type of damage in buildings.

A contribution to the selection of tsunami human vulnerability indicators: conclusions from tsunami impacts in Sri Lanka and Thailand (2004), Samoa (2009), Chile (2010) and Japan (2011)

NASA Astrophysics Data System (ADS)

González-Riancho, P.; Aliaga, B.; Hettiarachchi, S.; González, M.; Medina, R.

2015-07-01

After several tsunami events with disastrous consequences around the world, coastal countries have realized the need to be prepared to minimize human mortality and damage to coastal infrastructures, livelihoods and resources. The international scientific community is striving to develop and validate methodologies for tsunami hazard and vulnerability and risk assessments. The vulnerability of coastal communities is usually assessed through the definition of sets of indicators based on previous literature and/or post-tsunami reports, as well as on the available data for the study site. The aim of this work is to validate, in light of past tsunami events, the indicators currently proposed by the scientific community to measure human vulnerability, to improve their definition and selection as well as to analyse their validity for different country development profiles. The events analysed are the 2011 Great Tohoku tsunami, the 2010 Chilean tsunami, the 2009 Samoan tsunami and the 2004 Indian Ocean tsunami. The results obtained highlight the need for considering both permanent and temporal human exposure, the former requiring some hazard numerical modelling, while the latter is related to site-specific livelihoods, cultural traditions and gender roles. The most vulnerable age groups are the elderly and children, the former having much higher mortality rates. Female mortality is not always higher than male mortality and not always related to dependency issues. Higher numbers of disabled people do not always translate into higher numbers of victims. Besides, it is clear that mortality is not only related to the characteristics of the population but also of the buildings. A high correlation has been found between the affected buildings and the number of victims, being very high for completely damaged buildings. Distance to the sea, building materials and expected water depths are important determining factors regarding the type of damage to buildings.

A strain behavior before and after the 2009 Suruga-Bay earthquake (M6.5) in Tokai, Japan

NASA Astrophysics Data System (ADS)

Takanami, T.; Hirata, N.; Kitagawa, G.; Kamigaichi, O.; Linde, A. T.; Sacks, S. I.

2012-12-01

On 11 August 2009 the intraslab earthquake (M6.5) struck the Tokai area. The largest intensity observed was VI-in JMA scale, and it was a felt earthquake in a wide area including the Kanto and Koshin'estu Regions. Tsunamis were observed at and around the Suruga Bay. In the Tokai area, the Japan Meteorological Agency (JMA) continuously monitors strain data by the real time automated processing in the Tokai network. According to JMA, it is unconnected to the anticipated Tokai Earthquake (M8) judging from the acceptable reasons. For instance, it is an intraslab earthquake in the Philippine Sea plate, while the anticipated earthquake is a plate boundary earthquake on the upper side of the Philippine Sea plate. We consider it as an appropriate earthquake for validation of the Tokai network, though the feature of earthquake is different from one of the anticipated earthquake. We here tried to investigate the strain behavior before and after the 2009 Suruga Bay earthquake occurred in the fault zone of the anticipated Tokai earthquake. In actual, the Tokai network of strainmeters has been monitoring the short-term slow slip events (SSE) synchronized with nearby low frequency earthquakes or tremors since 2005 (Kobayashi et al., 2006). However, the earth's surface is always under the continuous influence of a variety of natural forces such as earthquakes, wave, wind, tide, air pressure, precipitation and a variety of human induced sources, which create noise when monitoring geodetic strain. Eliminating these noise inputs from the raw strain data requires proper statistical modeling, for automatic processing of geodetic strain data. It is desirable to apply the state space method to noisy Tokai strain data in order to detect precursors of the anticipated Tokai earthquake. The method is based on the general state space method, recursive filtering and smoothing algorithms (Kitagawa and Matsumoto, 1996). The first attempt to apply this method to actual strain data was made using data from the 2003 Tokachi-oki earthquake (M8.0) recorded by the Sacks-Evertson strainmeter, which has been operating since 1982 at Urakawa Seismological Observatory (KMU) of Hokkaido University in the southern part of the Hidaka Mountains (Takanami et al., 2009). KMU is far 105 km NW of the epicenter of the 2003 Tokachi-oki earthquake. After the earthquake, the data showed a clear episode of contraction for 4 days followed by expansion for 23 days. These signals correlate with increased aftershock seismicity for M≧4 events. The strain changes, together with surface displacements detected by the GPS network, are indicative of propagation of slow slip at depth (e.g. Geographical Survey Institute, 2004). We here review the computational approach to state space method and the results of its application to the strain data from the 2009 earthquakes (M6.5) occurred off Sagami in the Tokai area. Interestingly, for the 2011 Tohoku Earthquake off the Pacific coast no pre-slip was detected by land-based observations even though its magnitude was M9. In order to detect the nucleation of such an earthquake occurring far offshore, high-precision strain data is necessary but was not available.

Panel 2.17: private commercial sector partnerships for health action in crises.

PubMed

Sundnes, Knut Ole; Sannerkvist, Milan; Hedger, Philip; Woodworth, Brent; Hyre, Anne; Cuddyre, Terrence; Waldman, Ronald

2005-01-01

This is a summary of the presentations and discussion of Panel 2.17, Private Commercial Sector Partnerships for Health Action in Crises of the Conference, Health Aspects of the Tsunami Disaster in Asia, convened by the World Health Organization (WHO) in Phuket, Thailand, 04-06 May 2005. The topics discussed included issues related to private sector partnerships for health action in crises as pertain to the responses to the damage created by the Tsunami. It is presented in the following sections: (1) key questions; (2) issues and challenges; (3) lessons learned; (4) what was done well?; (5) what could have been done better?; and (6) conclusions and recommendations.

An Evaluation of Infrastructure for Tsunami Evacuation in Padang, West Sumatra, Indonesia (Invited)

NASA Astrophysics Data System (ADS)

Cedillos, V.; Canney, N.; Deierlein, G.; Diposaptono, S.; Geist, E. L.; Henderson, S.; Ismail, F.; Jachowski, N.; McAdoo, B. G.; Muhari, A.; Natawidjaja, D. H.; Sieh, K. E.; Toth, J.; Tucker, B. E.; Wood, K.

2009-12-01

Padang has one of the world’s highest tsunami risks due to its high hazard, vulnerable terrain and population density. The current strategy to prepare for tsunamis in Padang is focused on developing early warning systems, planning evacuation routes, conducting evacuation drills, and raising local awareness. Although these are all necessary, they are insufficient. Padang’s proximity to the Sunda Trench and flat terrain make reaching safe ground impossible for much of the population. The natural warning in Padang - a strong earthquake that lasts over a minute - will be the first indicator of a potential tsunami. People will have about 30 minutes after the earthquake to reach safe ground. It is estimated that roughly 50,000 people in Padang will be unable to evacuate in that time. Given these conditions, other means to prepare for the expected tsunami must be developed. With this motivation, GeoHazards International and Stanford University’s Chapter of Engineers for a Sustainable World partnered with Indonesian organizations - Andalas University and Tsunami Alert Community in Padang, Laboratory for Earth Hazards, and the Ministry of Marine Affairs and Fisheries - in an effort to evaluate the need for and feasibility of tsunami evacuation infrastructure in Padang. Tsunami evacuation infrastructure can include earthquake-resistant bridges and evacuation structures that rise above the maximum tsunami water level, and can withstand the expected earthquake and tsunami forces. The choices for evacuation structures vary widely - new and existing buildings, evacuation towers, soil berms, elevated highways and pedestrian overpasses. This interdisciplinary project conducted a course at Stanford University, undertook several field investigations, and concluded that: (1) tsunami evacuation structures and bridges are essential to protect the people in Padang, (2) there is a need for a more thorough engineering-based evaluation than conducted to-date of the suitability of existing buildings to serve as evacuation structures, and of existing bridges to serve as elements of evacuation routes, and (3) additions to Padang’s tsunami evacuation infrastructure must carefully take into account technical matters (e.g. expected wave height, debris impact forces), social considerations (e.g. cultural acceptability, public’s confidence in the structure’s integrity), and political issues (e.g. land availability, cost, maintenance). Future plans include collaboration between U.S. and Indonesian engineers in developing designs for new tsunami evacuation structures, as well as providing training for Indonesian authorities on: (1) siting, designing, and constructing tsunami evacuation structures, and (2) evaluating the suitability of existing buildings to serve as tsunami evacuation shelters.

Integration of WERA Ocean Radar into Tsunami Early Warning Systems

NASA Astrophysics Data System (ADS)

Dzvonkovskaya, Anna; Helzel, Thomas; Kniephoff, Matthias; Petersen, Leif; Weber, Bernd

2016-04-01

High-frequency (HF) ocean radars give a unique capability to deliver simultaneous wide area measurements of ocean surface current fields and sea state parameters far beyond the horizon. The WERA® ocean radar system is a shore-based remote sensing system to monitor ocean surface in near real-time and at all-weather conditions up to 300 km offshore. Tsunami induced surface currents cause increasing orbital velocities comparing to normal oceanographic situation and affect the measured radar spectra. The theoretical approach about tsunami influence on radar spectra showed that a tsunami wave train generates a specific unusual pattern in the HF radar spectra. While the tsunami wave is approaching the beach, the surface current pattern changes slightly in deep water and significantly in the shelf area as it was shown in theoretical considerations and later proved during the 2011 Japan tsunami. These observed tsunami signatures showed that the velocity of tsunami currents depended on a tsunami wave height and bathymetry. The HF ocean radar doesn't measure the approaching wave height of a tsunami; however, it can resolve the surface current velocity signature, which is generated when tsunami reaches the shelf edge. This strong change of the surface current can be detected by a phased-array WERA system in real-time; thus the WERA ocean radar is a valuable tool to support Tsunami Early Warning Systems (TEWS). Based on real tsunami measurements, requirements for the integration of ocean radar systems into TEWS are already defined. The requirements include a high range resolution, a narrow beam directivity of phased-array antennas and an accelerated data update mode to provide a possibility of offshore tsunami detection in real-time. The developed software package allows reconstructing an ocean surface current map of the area observed by HF radar based on the radar power spectrum processing. This fact gives an opportunity to issue an automated tsunami identification message by the WERA radars to TEWS. The radar measurements can be used to confirm a pre-warning and raise a tsunami alert. The output data of WERA processing software can be easily integrated into existing TEWS due to flexible data format, fast update rate and quality control of measurements. The archived radar data can be used for further hazard analysis and research purposes. The newly launched Tsunami Warning Center in Oman is one of the most sophisticated tsunami warning system world-wide applying a mix of well proven state-of-the-art subsystems. It allows the acquisition of data from many different sensor systems including seismic stations, GNSS, tide gauges, and WERA ocean radars in one acquisition system providing access to all sensor data via a common interface. The TEWS in Oman also integrates measurements of a modern network of HF ocean radars to verify tsunami simulations, which give additional scenario quality information and confirmation to the decision support.

Test operation of a real-time tsunami inundation forecast system using actual data observed by S-net

NASA Astrophysics Data System (ADS)

Suzuki, W.; Yamamoto, N.; Miyoshi, T.; Aoi, S.

2017-12-01

If the tsunami inundation information can be rapidly and stably forecast before the large tsunami attacks, the information would have effectively people realize the impeding danger and necessity of evacuation. Toward that goal, we have developed a prototype system to perform the real-time tsunami inundation forecast for Chiba prefecture, eastern Japan, using off-shore ocean bottom pressure data observed by the seafloor observation network for earthquakes and tsunamis along the Japan Trench (S-net) (Aoi et al., 2015, AGU). Because tsunami inundation simulation requires a large computation cost, we employ a database approach searching the pre-calculated tsunami scenarios that reasonably explain the observed S-net pressure data based on the multi-index method (Yamamoto et al., 2016, EPS). The scenario search is regularly repeated, not triggered by the occurrence of the tsunami event, and the forecast information is generated from the selected scenarios that meet the criterion. Test operation of the prototype system using the actual observation data started in April, 2017 and the performance and behavior of the system during non-tsunami event periods have been examined. It is found that the treatment of the noises affecting the observed data is the main issue to be solved toward the improvement of the system. Even if the observed pressure data are filtered to extract the tsunami signals, the noises in ordinary times or unusually large noises like high ocean waves due to storm affect the comparison between the observed and scenario data. Due to the noises, the tsunami scenarios are selected and the tsunami is forecast although any tsunami event does not actually occur. In most cases, the selected scenarios due to the noises have the fault models in the region along the Kurile or Izu-Bonin Trenches, far from the S-net region, or the fault models below the land. Based on the parallel operation of the forecast system with a different scenario search condition and examination of the fault models, we improve the stability and performance of the forecast system.This work was supported by Council for Science, Technology and Innovation(CSTI), Cross-ministerial Strategic Innovation Promotion Program (SIP), "Enhancement of societal resiliency against natural disasters"(Funding agency: JST).

Historical tsunami in the Azores archipelago (Portugal)

NASA Astrophysics Data System (ADS)

Andrade, C.; Borges, P.; Freitas, M. C.

2006-08-01

Because of its exposed northern mid-Atlantic location, morphology and plate-tectonics setting, the Azores Archipelago is highly vulnerable to tsunami hazards associated with landslides and seismic or volcanic triggers, local or distal. Critical examination of available data - written accounts and geologic evidence - indicates that, since the settlement of the archipelago in the 15th century, at least 23 tsunami have struck Azorean coastal zones. Most of the recorded tsunami are generated by earthquakes. The highest known run-up (11-15 m) was recorded on 1 November 1755 at Terceira Island, corresponding to an event of intensity VII-VIII (damaging-heavily damaging) on the Papadopolous-Imamura scale. To date, eruptive activity, while relatively frequent in the Azores, does not appear to have generated destructive tsunami. However, this apparent paucity of volcanogenic tsunami in the historical record may be misleading because of limited instrumental and documentary data, and small source-volumes released during historical eruptions. The latter are in contrast with the geological record of massive pyroclastic flows and caldera explosions with potential to generate high-magnitude tsunami, predating settlement. In addition, limited evidence suggests that submarine landslides from unstable volcano flanks may have also triggered some damaging tsunamigenic floods that perhaps were erroneously attributed to intense storms. The lack of destructive tsunami since the mid-18th century has led to governmental complacency and public disinterest in the Azores, as demonstrated by the fact that existing emergency regulations concerning seismic events in the Azores Autonomous Region make no mention of tsunami and their attendant hazards. We suspect that the coastal fringe of the Azores may well preserve a sedimentary record of some past tsunamigenic flooding events. Geological field studies must be accelerated to expand the existing database to include prehistoric events-information essential for more precisely estimating the average tsunami recurrence rate for the Azores over a longer period. A present-day occurrence of a moderate to intense tsunami (i.e., the size of the 1755 event) would produce societal disruption and economic loss orders of magnitudes greater than those of previous events in Azorean history. To reduce risk from future tsunami, comprehensive assessment of tsunami hazards and the preparation of hazards-zonation maps are needed to guide governmental decisions on issues of prudent land-use planning, public education and emergency management.

Determination of Tsunami Warning Criteria for Current Velocity

NASA Astrophysics Data System (ADS)

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.

Economic losses to buildings due to tsunami impact: the case of Rhodes city, Greece

NASA Astrophysics Data System (ADS)

Triantafyllou, Ioanna; Novikova, Tatyana; Papadopoulos, Gerassimos

2017-04-01

The expected economic losses to buildings due to the tsunami impact is of particular importance for the tsunami risk management. However, only few efforts can be found in this direction. In this study we approached this issue selecting the city of Rhodes Isl., Greece, as a test-site. The methodological steps followed include (a) selection of worst case scenario in the study area based on the tsunami history of the area which includes several powerful events, e.g. 142 AD, 1303, 1481, 1609, 1741, (b) numerical simulation of the tsunami and determination of the inundation zone, (c) application of the DAMASCHE empirical tool, produced by the SCHEMA EU-FP6 project, for the calculation of the damage level expected at each one of the buildings as a function of the water depth in the inundation area, (d) calculation of the buildings that would need reparation after partial damage and of those that would need reconstruction after total destruction, (e) calculation of the cost implied for both reparation and reconstruction. The several data sets which are needed for the execution of these steps, are susceptible to uncertainties and, therefore, the final results are quite sensitive to changes of the data sets. Alternative costs were calculated by taking into account the several uncertainties involved. This research is a contribution to the EU-FP7 tsunami research project ASTARTE (Assessment, Strategy And Risk Reduction for Tsunamis in Europe), grant agreement no: 603839, 2013-10-30.

How soon is too soon? When to cancel a warning after a damaging tsunami

NASA Astrophysics Data System (ADS)

Fryer, G. J.; Becker, N. C.; Wang, D.; Weinstein, S.; Richards, K.

2012-12-01

Following an earthquake a tsunami warning center (TWC) must determine if a coastal evacuation is necessary and must do so fast enough for the warning to be useful to affected coastlines. Once a damaging tsunami has arrived, the TWC must decide when to cancel its warning, a task often more challenging than the initial hazard assessment. Here we demonstrate the difficulties by investigating the impact of the Tohoku tsunami of 11 March 2011 on the State of Hawaii, which relies on the Pacific Tsunami Warning Center (PTWC) for tsunami hazard guidance. PTWC issued a Tsunami Watch for Hawaii at 10 March 1956 HST (10 minutes after the earthquake) and upgraded to a Tsunami Warning at 2131 HST. The tsunami arrived in Hawaii just before 0300 HST the next day, reached a maximum runup of over 5 m, and did roughly $50 million in damage throughout the state. PTWC downgraded the Warning to an Advisory at 0730 HST, and canceled the Advisory at 1140 HST. The timing of the downgrade was appropriate—by then it was safe for coastal residents to re-enter the evacuation zone but not to enter the water—but in retrospect PTWC cancelled its Advisory too early. By late morning tide gauges throughout the state had all registered maximum wave heights of 30 cm or less for a couple of hours, so PTWC cancelled. The Center was unaware, however, of ocean behavior at locations without instruments. At Ma'alaea Harbor on the Island of Maui, for example, sea level oscillations exposed the harbor bottom every 20 minutes for several hours after the cancellation. At Waikiki on Oahu, lifeguards rescued 25 swimmers (who had either ignored or were unaware of the cancellation message's caution about hazardous currents) in the hours after the cancellation and performed CPR on one near-drowning victim. Fortunately, there were no deaths. Because of dangerous surges, ocean safety officials closed Hanauma Bay, a popular snorkeling spot on Oahu, for a full day after the tsunami hit. They reassessed the bay the following morning just as waves reflected from South America started to arrive (36 hours after the earthquake), and prudently chose to keep the bay closed for two further days. The Tohoku tsunami showed that resonances and trapped waves in shallow water can last for many hours and that energy reflected from distant shorelines can rejuvenate them. PTWC's real-time simulation of the tsunami, including animation of its propagation, now helps to identify which reflections will be most troublesome and should permit the Center to specify in advance how long a Warning should remain in effect. The current open-ended warnings, which specify when the tsunami will arrive but not how long the Warning should last, should be replaced with warnings active for a specified time ("until 3 a.m. tomorrow"), with PTWC adjusting the projected cancellation time based on coastal sea-level observations. Such warnings should greatly reduce public misconceptions and state and local government expectations about how long the hazard will last. The National Weather Service, parent agency of the US TWCs, already issues weather Warnings and Advisories active for specific durations, so this message format is already familiar to both the public and emergency managers.

Emergency management response to a warning-level Alaska-source tsunami impacting California: Chapter J in The SAFRR (Science Application for Risk Reduction) Tsunami Scenario

USGS Publications Warehouse

Miller, Kevin M.; Long, Kate

2013-01-01

This chapter is directed towards two audiences: Firstly, it targets nonemergency management readers, providing them with insight on the process and challenges facing emergency managers in responding to tsunami Warning, particularly given this “short fuse” scenario. It is called “short fuse” because there is only a 5.5-hour window following the earthquake before arrival of the tsunami within which to evaluate the threat, disseminate alert and warning messages, and respond. This action initiates a period when crisis communication is of paramount importance. An additional dynamic that is important to note is that within 15 minutes of the earthquake, the National Oceanic and Atmospheric Administration (NOAA) and the National Weather Service (NWS) will issue alert bulletins for the entire Pacific Coast. This is one-half the time actually presented by recent tsunamis from Japan, Chile, and Samoa. Second, the chapter provides emergency managers at all levels with insights into key considerations they may need to address in order to augment their existing plans and effectively respond to tsunami events. We look at emergency management response to the tsunami threat from three perspectives:“Top Down” (Threat analysis and Alert/Warning information from the Federal agency charged with Alert and Warning) “Bottom Up” (Emergency management’s Incident Command approach to responding to emergencies and disasters based on the needs of impacted local jurisdictions) “Across Time” (From the initiating earthquake event through emergency response) We focus on these questions: What are the government roles, relationships, and products that support Tsunami Alert and Warning dissemination? (Emergency Planning and Preparedness.) What roles, relationships, and products support emergency management response to Tsunami Warning and impact? (Engendering prudent public safety response.) What are the key emergency management activities, considerations, and challenges brought out by the SAFRR tsunami scenario? (Real emergencies) How do these activities, considerations, and challenges play out as the tsunami event unfolds across the “life” of the event? (Lessons)

Integrating Caribbean Seismic and Tsunami Hazard into Public Policy and Action

NASA Astrophysics Data System (ADS)

von Hillebrandt-Andrade, C.

2012-12-01

The Caribbean has a long history of tsunamis and earthquakes. Over the past 500 years, more than 80 tsunamis have been documented in the region by the NOAA National Geophysical Data Center. Almost 90% of all these historical tsunamis have been associated with earthquakes. Just since 1842, 3510 lives have been lost to tsunamis; this is more than in the Northeastern Pacific for the same time period. With a population of almost 160 million and a heavy concentration of residents, tourists, businesses and critical infrastructure along the Caribbean shores (especially in the northern and eastern Caribbean), the risk to lives and livelihoods is greater than ever before. Most of the countries also have a very high exposure to earthquakes. Given the elevated vulnerability, it is imperative that government officials take steps to mitigate the potentially devastating effects of these events. Nevertheless, given the low frequency of high impact earthquakes and tsunamis, in comparison to hurricanes, combined with social and economic considerations, the needed investments are not made and disasters like the 2010 Haiti earthquake occur. In the absence of frequent significant events, an important driving force for public officials to take action, is the dissemination of scientific studies. When papers of this nature have been published and media advisories issued, public officials demonstrate heightened interest in the topic which in turn can lead to increased legislation and funding efforts. This is especially the case if the material can be easily understood by the stakeholders and there is a local contact. In addition, given the close link between earthquakes and tsunamis, in Puerto Rico alone, 50% of the high impact earthquakes have also generated destructive tsunamis, it is very important that earthquake and tsunami hazards studies demonstrate consistency. Traditionally in the region, earthquake and tsunami impacts have been considered independently in the emergency planning processes. For example, earthquake and tsunami exercises are conducted separately, without taking into consideration the compounding effects. Recognizing this deficiency, the UNESCO IOC Intergovernmental Coordination Group for the Tsunami and other Coastal Hazards Warning System for the Caribbean and Adjacent Regions (CARIBE EWS) which was established in 2005, decided to include the tsunami and earthquake impacts for the upcoming March 20, 2013 regional CARIBE WAVE/LANTEX tsunami exercise. In addition to the tsunami wave heights predicted by the National Weather Service Tsunami Warning Centers in Alaska and Hawaii, the USGS PAGER and SHAKE MAP results for the M8.5 scenario earthquake in the southern Caribbean were also integrated into the manual. Additionally, in recent catastrophic planning for Puerto Rico, FEMA did request the local researchers to determine both the earthquake and tsunami impacts for the same source. In the US, despite that the lead for earthquakes and tsunamis lies within two different agencies, USGS and NOAA/NWS, it has been very beneficial that the National Tsunami Hazard Mitigation Program partnership includes both agencies. By working together, the seismic and tsunami communities can achieve an even better understanding of the hazards, but also foster more actions on behalf of government officials and the populations at risk.

On mitigating rapid onset natural disasters: Project THRUST (Tsunami Hazards Reduction Utilizing Systems Technology)

NASA Astrophysics Data System (ADS)

Bernard, E. N.; Behn, R. R.; Hebenstreit, G. T.; Gonzalez, F. I.; Krumpe, P.; Lander, J. F.; Lorca, E.; McManamon, P. M.; Milburn, H. B.

Rapid onset natural hazards have claimed more than 2.8 million lives worldwide in the past 20 years. This category includes such events as earthquakes, landslides, hurricanes, tornados, floods, volcanic eruptions, wildfires, and tsunamis. Effective hazard mitigation is particularly difficult in such cases, since the time available to issue warnings can be very short or even nonexistent. This paper presents the concept of a local warning system that exploits and integrates the existing technologies of risk evaluation, environmental measurement, and telecommunications. We describe Project THRUST, a successful implementation of this general, systematic approach to tsunamis. The general approach includes pre-event emergency planning, real-time hazard assessment, and rapid warning via satellite communication links.

REWSET: A prototype seismic and tsunami early warning system in Rhodes island, Greece

NASA Astrophysics Data System (ADS)

Papadopoulos, Gerasimos; Argyris, Ilias; Aggelou, Savvas; Karastathis, Vasilis

2014-05-01

Tsunami warning in near-field conditions is a critical issue in the Mediterranean Sea since the most important tsunami sources are situated within tsunami wave travel times starting from about five minutes. The project NEARTOWARN (2012-2013) supported by the EU-DG ECHO contributed substantially to the development of new tools for the near-field tsunami early warning in the Mediterranean. One of the main achievements is the development of a local warning system in the test-site of Rhodes island (Rhodes Early Warning System for Earthquakes and Tsunamis - REWSET). The system is composed by three main subsystems: (1) a network of eight seismic early warning devices installed in four different localities of the island, one in the civil protection, another in the Fire Brigade and another two in municipality buildings; (2) two radar-type (ultrasonic) tide-gauges installed in the eastern coastal zine of the island which was selected since research on the historical earthquake and tsunami activity has indicated that the most important, near-field tsunami sources are situated offshore to the east of Rhodes; (3) a crisis Geographic Management System (GMS), which is a web-based and GIS-based application incorporating a variety of thematic maps and other information types. The seismic early warning devices activate by strong (magnitude around 6 or more) earthquakes occurring at distances up to about 100 km from Rhodes, thus providing immediate mobilization of the civil protection. The tide-gauges transmit sea level data, while during the crisis the GMS supports decisions to be made by civil protection. In the near future it is planned the REWSET system to be integrated with national and international systems. REWSET is a prototype which certainly could be developed in other coastal areas of the Mediterranean and beyond.

Green reconstruction of the tsunami-affected areas in India using the integrated coastal zone management concept.

PubMed

Sonak, Sangeeta; Pangam, Prajwala; Giriyan, Asha

2008-10-01

A tsunami, triggered by a massive undersea earthquake off Sumatra in Indonesia, greatly devastated the lives, property and infrastructure of coastal communities in the coastal states of India, Andaman and Nicobar Islands, Indonesia, Sri Lanka, Malaysia and Thailand. This event attracted the attention of environmental managers at all levels, local, national, regional and global. It also shifted the focus from the impact of human activities on the environment to the impacts of natural hazards. Recovery/reconstruction of these areas is highly challenging. A clear understanding of the complex dynamics of the coast and the types of challenges faced by the several stakeholders of the coast is required. Issues such as sustainability, equity and community participation assume importance. The concept of ICZM (integrated coastal zone management) has been effectively used in most parts of the world. This concept emphasizes the holistic assessment of the coast and a multidisciplinary analysis using participatory processes. It integrates anthropocentric and eco-centric approaches. This paper documents several issues involved in the recovery of tsunami-affected areas and recommends the application of the ICZM concept to the reconstruction efforts.

Maritime Tsunami Hazard Assessment in California

NASA Astrophysics Data System (ADS)

Lynett, P. J.; Borrero, J. C.; Wilson, R. I.; Miller, K. M.

2012-12-01

The California tsunami program in cooperation with NOAA and FEMA has begun implementing a plan to increase awareness of tsunami generated hazards to the maritime community (both ships and harbor infrastructure) through the development of in-harbor hazard maps, offshore safety zones for boater evacuation, and associated guidance for harbors and marinas before, during and following tsunamis. The hope is that the maritime guidance and associated education and outreach program will help save lives and reduce exposure of damage to boats and harbor infrastructure. An important step in this process is to understand the causative mechanism for damage in ports and harbors, and then ensure that the models used to generate hazard maps are able to accurately simulate these processes. Findings will be used to develop maps, guidance documents, and consistent policy recommendations for emergency managers and port authorities and provide information critical to real-time decisions required when responding to tsunami alert notifications. Basin resonance and geometric amplification are two reasonably well understood mechanisms for local magnification of tsunami impact in harbors, and are generally the mechanisms investigated when estimating the tsunami hazard potential in a port or harbor. On the other hand, our understanding of and predictive ability for currents is lacking. When a free surface flow is forced through a geometric constriction, it is readily expected that the enhanced potential gradient will drive strong, possibly unstable currents and the associated turbulent coherent structures such as "jets" and "whirlpools"; a simple example would be tidal flow through an inlet channel. However, these fundamentals have not been quantitatively connected with respect to understanding tsunami hazards in ports and harbors. A plausible explanation for this oversight is the observation that these features are turbulent phenomena with spatial and temporal scales much smaller than that of a typical tsunami. The ability to model and then validate these currentsdissect them has only recently become available through the evaluation of dozens of eyewitness accounts and hundreds of videos.developed. In this presentation, we will present ongoing work related to the application of such models to quantify the maritime tsunami hazard in select ports and harbors in California. The development of current-based tsunami hazard maps and safe-offshore-depth delineations will be discussed. We will also present an overview of the challenges in modeling tsunami currents, including capture of turbulent dynamics, coupling with tides, and issues with long-duration simulations. This work in California will form the basis for tsunami hazard reduction for all U.S. maritime communities through the National Tsunami Hazard Mitigation Program.

Five years from the great 2010 Tsunami in Chile: learning from multi-hazard disasters and improving resileincy

NASA Astrophysics Data System (ADS)

Cienfuegos, R.; Gonzalez, G.; Repetto, P.; Cipriano, A.; Moris, R.; Catalan, P. A.; Guic, E.; Martin, J. C. D. L. L.

2016-12-01

The Research Center for Integrated Natural Hazards Management (CIGIDEN) has developed in recent years (supported by the Fondap/Conicyt Excellence in research center's program) active efforts to connect science and public institutions in charge of disaster management in Chile. We have been able to reach in particular the National Emergency Office (ONEMI) and the National Hydrographic and Oceanographic Naval Service (SHOA), and develop joint specific programs that have been mutually beneficial both for research enrichment and the operation of the emergency response system. Through these efforts, also supplemented by other Chilean and International research institutions, we analyzed together issues and challenges from the systemic failure experienced by the emergency system in Chile after the 2010 earthquake and tsunami. In this talk we will review some of the main collaboration actions and their outcomes, connecting them to the extreme events that impacted Chile in 2015 (earthquakes, tsunamis, storm waves, and flash floods). In particular we will describe the effort that CIGIDEN has developed i) with ONEMI in developing instruments to assess community preparedness and awareness and to understand tsunami evacuation behaviors; and ii) with SHOA to develop a new Integrated Decision Support System for Tsunami alerting that is being transferred to SHOA in September 2015, and was successfully tested offline during the September 16th, 2015, tsunami.

Use of Advanced Tsunami Hazard Assessment Techniques and Tsunami Source Characterizations in U.S. and International Nuclear Regulatory Activities

NASA Astrophysics Data System (ADS)

Kammerer, A. M.; Godoy, A. R.

2009-12-01

In response to the 2004 Indian Ocean Tsunami, as well as the anticipation of the submission of license applications for new nuclear facilities, the United States Nuclear Regulatory Commission (US NRC) initiated a long-term research program to improve understanding of tsunami hazard levels for nuclear power plants and other coastal facilities in the United States. To undertake this effort, the US NRC organized a collaborative research program jointly undertaken with researchers at the United States Geological Survey (USGS) and the National Oceanic and Atmospheric Administration (NOAA) for the purpose of assessing tsunami hazard on the Atlantic and Gulf Coasts of the United States. This study identified and modeled both seismic and landslide tsunamigenic sources in the near- and far-field. The results from this work are now being used directly as the basis for the review of tsunami hazard at potential nuclear plant sites. This application once again shows the importance that the earth sciences can play in addressing issues of importance to society. Because the Indian Ocean Tsunami was a global event, a number of cooperative international activities have also been initiated within the nuclear community. The results of US efforts are being incorporated into updated regulatory guidance for both the U.S. Nuclear Regulatory Commission and the United Nation’s International Atomic Energy Agency (IAEA). Coordinated efforts are underway to integrate state-of-the art tsunami warning tools developed by NOAA into NRC and IAEA activities. The goal of the warning systems project is to develop automated protocols that allow scientists at these agencies to have up-to-the minute user-specific information in hand shortly after a potential tsunami has been identified by the US Tsunami Warning System. Lastly, USGS and NOAA scientists are assisting the NRC and IAEA in a special Extra-Budgetary Program (IAEA EBP) on tsunami being coordinated by the IAEA’s International Seismic Safety Center. This IAEA EBP is focused on sharing lessons learned, tsunami hazard assessment techniques, and numerical tools among UN Member States. The complete body of basic and applied research undertaken in these many projects represents the combined effort of a diverse group of marine geologists, geophysicists, geotechnical engineers, seismologists and hydrodynamic modelers at multiple organizations.

Faster from the Depths to Decision: Collecting, Distributing, and Applying Data from NOAA`s Deep-Sea Tsunameters

NASA Astrophysics Data System (ADS)

Bouchard, R. H.; Wang, D.; Branski, F.

2008-05-01

The National Oceanic and Atmospheric Administration (NOAA) operates two tsunami warning centers (TWCs): the West Coast/Alaska Tsunami Warning Center (ATWC) and Pacific Tsunami Warning Center (PTWC). ATWC provides tsunami alerts to Canadian coastal regions, Virgin Islands, Puerto Rico, and the coasts of continental US and Alaska. PTWC provides local/regional tsunami alerts/advisories to the state of Hawaii. An operational center of the Tsunami Warning System of the Pacific, it provides tsunami alerts to most countries of the Pacific Rim. PTWC also provides tsunami alerts for the Caribbean and Indian Ocean countries on an interim basis. The TWCs aim to issue first tsunami bulletins within 10-15 minutes of the earthquake for tele-tsunamis and within a few minutes for local tsunamis. The TWCs have a requirement for offshore tsunami detection in real-time with a data latency of 1 minute or less. Offshore detection of tsunamis is the purpose of NOAA`s recently completed 39-station array of deep-sea tsunameters. The tsunameters, employing the second-generation DART (Deep-ocean Assessment and Reporting of Tsunamis) technology, can speed tsunami detection information to the TWCs in less than 3 minutes from depths of 6000 meters in the Pacific and Western Atlantic oceans. The tsunameters consist of a Bottom Pressure Recorder (BPR) and a surface buoy. Communication from the BPR to the buoy is via underwater acoustic transmissions. Satellite communications carry the data from the buoy to NOAA`s National Data Buoy Center (NDBC), which operates the tsunameters. The BPRs make pressure measurements, converts them to an equivalent water-column height, and passes them through a tsunami detection algorithm. If the algorithm detects a sufficient change in the height, the tsunameter goes into a rapid reporting mode or Event Mode. The acoustic modem-satellite telecommunications path takes approximately 50 seconds to reach the NDBC server. In a few seconds, NDBC reformats the data and pushes them as messages to the National Weather Service Telecommunications Gateway also known as World Meteorological Organization (WMO) Regional Telecommunication Hub (RTH) Washington. RTH Washington can route more than 50 routine messages per second with reliability for all dissemination to all of its users of 99.9 percent. It provides a latency for high priority traffic of 10 seconds or less and routinely handles 1.2 TB of information per day. Its switching centers are on the Main Trunk Network of the WMO`s Global Telecommunication System (GTS), which provides international distribution of the tsunameter data. The GTS is required to deliver tsunami data and warnings to any connected center within two minutes anywhere in the world. TWCs receive the tsunameter data from RTH Washington via GTS circuits, or download the data from servers at the RTH, in the event the GTS circuits fails. TWCs display the data in real-time in their operations. When a tsunameter goes into Event Mode, the TWCs receive alerts. After subtracting the tide, tsunameter signals can measure tsunamis as small as a few millimeters. The usefulness of the tsunameter data at TWCs was demonstrated in some of the recent events in the Pacific Ocean (Kuril Tsunamis of November 2006 and January 2007, Peru Tsunamis of August 2007 and September 2007) and the Indian Ocean (Southern Sumatra Tsunami of September 2007).

The Redwood Coast Tsunami Work Group: a unique organization promoting earthquake and tsunami resilience on California's North Coast

NASA Astrophysics Data System (ADS)

Dengler, L.; Henderson, C.; Larkin, D.; Nicolini, T.; Ozaki, V.

2012-12-01

The Northern California counties of Del Norte, Humboldt, and Mendocino account for over 30% of California's coastline and is one of the most seismically active areas of the contiguous 48 states. The region is at risk from earthquakes located on- and offshore and from tsunamis generated locally from faults associated with the Cascadia subduction zone (CSZ) and from distant sources elsewhere in the Pacific. In 1995 the California Geological Survey (CGS) published a scenario for a CSZ earthquake that included both strong ground shaking effects and a tsunami. As a result of the scenario, the Redwood Coast Tsunami Work Group (RCTWG), an organization of government agencies, tribes, service groups, academia and the private sector, was formed to coordinate and promote earthquake and tsunami hazard awareness and mitigation in the three-county region. The RCTWG and its member agencies projects include education/outreach products and programs, tsunami hazard mapping, signage and siren planning. Since 2008, RCTWG has worked with the California Emergency Management Agency (Cal EMA) in conducting tsunami warning communications tests on the North Coast. In 2007, RCTWG members helped develop and carry out the first tsunami training exercise at FEMA's Emergency Management Institute in Emmitsburg, MD. The RCTWG has facilitated numerous multi-agency, multi-discipline coordinated exercises, and RCTWG county tsunami response plans have been a model for other regions of the state and country. Eight North Coast communities have been recognized as TsunamiReady by the National Weather Service, including the first National Park the first State Park and only tribe in California to be so recognized. Over 500 tsunami hazard zone signs have been posted in the RCTWG region since 2008. Eight assessment surveys from 1993 to 2010 have tracked preparedness actions and personal awareness of earthquake and tsunami hazards in the county and additional surveys have tracked public awareness and tourist concerns about tsunami hazard signs. Over the seventeen-year period covered by the surveys, the percent with houses secured to foundations has increased from 58 to 84 percent, respondents aware of a local tsunami hazard increased from 51 to 89 percent and knowing what the Cascadia subduction zone is from 16 to 57 percent. In 2009, the RCTWG was recognized by the Western States Seismic Policy Council (WSSPC) with an award for innovation and in 2010, the RCTWG-sponsored class "Living on Shaky Ground" was awarded WSSPC's overall Award in Excellence. The RCTWG works closely with CGS and Cal EMA on a number of projects including tsunami mapping, evacuation zone planning, siren policy, tsunami safety for boaters, and public education messaging. Current projects include working with CGS to develop a "playbook" tsunami mapping product to illustrate the expected effects from a range of tsunami source events and assist local governments in focusing future response actions to reflect the range expected impacts from distant source events. Preparedness efforts paid off on March 11, 2011 when a tsunami warning was issued for the region and significant damage occurred in harbor regions of Del Norte County and Mendocino County. Full-scale evacuations were carried out in a coordinated manner and the majority of the commercial fishing fleet in Crescent City was able to exit the harbor before the tsunami arrived.

State Emergency Response and Field Observation Activities in California (USA) during the March 11, 2011, Tohoku Tsunami

NASA Astrophysics Data System (ADS)

Miller, K. M.; Wilson, R. I.; Goltz, J.; Fenton, J.; Long, K.; Dengler, L.; Rosinski, A.; California Tsunami Program

2011-12-01

This poster will present an overview of successes and challenges observed by the authors during this major tsunami response event. The Tohoku, Japan tsunami was the most costly to affect California since the 1964 Alaskan earthquake and ensuing tsunami. The Tohoku tsunami caused at least $50 million in damage to public facilities in harbors and marinas along the coast of California, and resulted in one fatality. It was generated by a magnitude 9.0 earthquake which occurred at 9:46PM PST on Thursday, March 10, 2011 in the sea off northern Japan. The tsunami was recorded at tide gages monitored by the West Coast/Alaska Tsunami Warning Center (WCATWC), which projected tsunami surges would reach California in approximately 10 hours. At 12:51AM on March 11, 2011, based on forecasted tsunami amplitudes, the WCATWC placed the California coast north of Point Conception (Santa Barbara County) in a Tsunami Warning, and the coast south of Point Conception to the Mexican border in a Tsunami Advisory. The California Emergency Management Agency (CalEMA) activated two Regional Emergency Operation Centers (REOCs) and the State Operation Center (SOC). The California Geological Survey (CGS) deployed a field team which collected data before, during and after the event through an information clearinghouse. Conference calls were conducted hourly between the WCATWC and State Warning Center, as well as with emergency managers in the 20 coastal counties. Coordination focused on local response measures, public information messaging, assistance needs, evacuations, emergency shelters, damage, and recovery issues. In the early morning hours, some communities in low lying areas recommended evacuation for their citizens, and the fishing fleet at Crescent City evacuated to sea. The greatest damage occurred in the harbors of Crescent City and Santa Cruz. As with any emergency, there were lessons learned and important successes in managing this event. Forecasts by the WCATWC were highly accurate. Exercises and workshops have enhanced communications between state and local agencies, and emergency managers are more educated about what to expect. Areas for improvement include keeping people out of the hazard area; educating the non-English speaking community; and reinforcing the long duration and unpredictable peak damaging waves of these events to emergency managers. The Governor proclaimed a state of emergency in six counties and the President declared a major disaster on April 18, 2011, allowing federal assistance to support repairs and economic recovery. Detailed evaluation of local maritime response activities, harbor damage, and measured and observed tsunami current velocity data will help the California Tsunami Program develop improved tsunami hazard maps and guidance for maritime communities. The state program will continue to emphasize the importance of both tsunami warnings and advisories, the unpredictable nature of each tsunami, and encourage public understanding of tsunamis to prepare and protect themselves in the future.

Session 1.5: health policy and coordination: a critical review of experiences.

PubMed

Procacci, Pasqualino; Doran, Rodger; Chunkath, Sheela Rani; Garfield, Richard; Briceno, Salvano; Fric, Anton

2005-01-01

This is a summary of the presentations and discussion of Session 1.5 on Health Policy and Coordination: A Critical Review of Experiences during the Conference, Health Aspects of the Tsunami Disaster in Asia, convened by the World Health Organization (WHO) in Phuket, Thailand, 04-06 May 2005. The topics discussed included issues related to health policy and coordination as pertain to the responses to the damage created by the Tsunami. Key questions were answered in this session, and recommendations were made.

Tsunami warnings: Understanding in Hawai'i

USGS Publications Warehouse

Gregg, Chris E.; Houghton, Bruce F.; Paton, Douglas; Johnston, David M.; Swanson, D.A.; Yanagi, B.S.

2007-01-01

The devastating southeast Asian tsunami of December 26, 2004 has brought home the destructive consequences of coastal hazards in an absence of effective warning systems. Since the 1946 tsunami that destroyed much of Hilo, Hawai'i, a network of pole mounted sirens has been used to provide an early public alert of future tsunamis. However, studies in the 1960s showed that understanding of the meaning of siren soundings was very low and that ambiguity in understanding had contributed to fatalities in the 1960 tsunami that again destroyed much of Hilo. The Hawaiian public has since been exposed to monthly tests of the sirens for more than 25 years and descriptions of the system have been widely published in telephone books for at least 45 years. However, currently there remains some uncertainty in the level of public understanding of the sirens and their implications for behavioral response. Here, we show from recent surveys of Hawai'i residents that awareness of the siren tests and test frequency is high, but these factors do not equate with increased understanding of the meaning of the siren, which remains disturbingly low (13%). Furthermore, the length of time people have lived in Hawai'i is not correlated systematically with understanding of the meaning of the sirens. An additional issue is that warning times for tsunamis gene rated locally in Hawai'i will be of the order of minutes to tens of minutes and limit the immediate utility of the sirens. Natural warning signs of such tsunamis may provide the earliest warning to residents. Analysis of a survey subgroup from Hilo suggests that awareness of natural signs is only moderate, and a majority may expect notification via alerts provided by official sources. We conclude that a major change is needed in tsunami education, even in Hawai'i, to increase public understanding of, and effective response to, both future official alerts and natural warning signs of future tsunamis. ?? Springer 2006.

Panel 2.18: logistics, information technology (IT), and telecommunications in crisis management.

PubMed

De Silva, Terrence; Chikersal, Jyotsna; Snoad, Nigel; Woodworth, Brent; Ghaly, Cherif; Catterall, Martin

2005-01-01

This is a summary of the presentations and discussion of Panel 2.18, Logistics, Information Technology, and Telecommunications in Crisis Management of the Conference, Health Aspects of the Tsunami Disaster in Asia, convened by the World Health Organization (WHO) in Phuket, Thailand, 04-06 May 2005. The topics discussed included issues related to logistics, information technology (IT), and crisis communication pertaining to the responses to the damage created by the Tsunami. It is presented in the following major sections: (1) issues; (2) lessons learned; (3) what was done well; (4) what could have been done better; and (5) conclusions and recommendations. Each major section is presented in four sub-sections: (1) needs assessments; (2) coordination; (3) filling the gaps; and (4) capacity building.

Place-classification analysis of community vulnerability to near-field tsunami threats in the U.S. Pacific Northwest

NASA Astrophysics Data System (ADS)

Wood, N. J.; Spielman, S.

2012-12-01

Near-field tsunami hazards are credible threats to many coastal communities throughout the world. Along the U.S. Pacific Northwest coast, low-lying areas could be inundated by a series of catastrophic tsunamis that begin to arrive in a matter of minutes following a major Cascadia subduction zone (CSZ) earthquake. Previous research has documented the residents, employees, tourists at public venues, customers at local businesses, and vulnerable populations at dependent-care facilities that are in CSZ-related tsunami-prone areas of northern California, Oregon, and the open-ocean coast of Washington. Community inventories of demographic attributes and other characteristics of the at-risk population have helped emergency managers to develop preparedness and outreach efforts. Although useful for distinct risk-reduction issues, these data can be difficult to fully appreciate holistically given the large number of community attributes. This presentation summarizes analytical efforts to classify communities with similar characteristics of community exposure to tsunami hazards. This work builds on past State-focused inventories of community exposure to CSZ-related tsunami hazards in northern California, Oregon, and Washington. Attributes used in the classification, or cluster analysis, fall into several categories, including demography of residents, spatial extent of the developed footprint based on mid-resolution land cover data, distribution of the local workforce, and the number and type of public venues, dependent-care facilities, and community-support businesses. As we were unsure of the number of different types of communities, we used an unsupervised-model-based clustering algorithm and a v-fold, cross-validation procedure (v=50) to identify the appropriate number of community types. Ultimately we selected class solutions that provided the appropriate balance between parsimony and model fit. The goal of the exposure classification is to provide emergency managers with a general sense of the types of communities in tsunami hazard zones based on similar exposure characteristics instead of only providing an exhaustive list of attributes for individual communities. This community-exposure classification scheme can be then used to target and prioritize risk-reduction efforts that address common issues across multiple communities, instead of community-specific efforts. Examples include risk-reduction efforts that focus on similar demographic attributes of the at-risk population or on the type of service populations that dominate tsunami-prone areas. The presentation will include a discussion of the utility of proposed place classifications to support regional preparedness and outreach efforts.

Tsunami Hazard in the Algerian Coastline

NASA Astrophysics Data System (ADS)

Amir, L. A.

2008-05-01

The Algerian coastline is located at the border between the African and the Eurasian tectonic plates. The collision between these two plates is approximately 4 to 7 mm/yr. The Alps and the tellian Atlas result from this convergence. Historical and present day data show the occurrence of earthquakes with magnitude up to 7 degrees on Richter scale in the northern part of the country. Cities were destroyed and the number of victims reached millions of people. Recently, small seismic waves generated by a destructive earthquake (Epicenter: 36.90N, 3.71E; Mw=6.8; Algeria, 2003, NEIC) were recorded in the French and Spanish coasts. This event raised again the issue of tsunami hazard in western Mediterranean region. For the Algerian study case, the assessment of seismic and tsunami hazard is a matter of great interest because of fast urban development of cities like Algiers. This study aims to provide scientific arguments to help in the elaboration of the Mediterranean tsunami alert program. This is a real complex issue because (1) the western part of the sea is narrow, (2) constructions on the Algerian coastline do not respect safety standards and (3) the seismic hazard is important. The present work is based on a numerical modeling approach. Firstly, a database is created to gather and list information related to seismology, tectonic, abnormal sea level's variations recorded/observed, submarine and coastal topographic data for the western part of the Mediterranean margin. This database helped to propose series of scenario that could trigger tsunami in the Mediterranean sea. Seismic moment, rake and focal depth are the major parameters that constrain the modeling input seismic data. Then, the undersea earthquakes modeling and the seabed deformations are computed with a program adapted from the rngchn code based on Okada's analytic equations. The last task of this work consisted to calculate the initial water surface displacement and simulate the triggered tsunami. 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.

Survey of the July 17, 2006 Central Javan tsunami reveals 21m runup heights

NASA Astrophysics Data System (ADS)

Fritz, H.; Goff, J.; Harbitz, C.; McAdoo, B.; Moore, A.; Latief, H.; Kalligeris, N.; Kodjo, W.; Uslu, B.; Titov, V.; Synolakis, C.

2006-12-01

The Monday, July 17, 2006 Central Javan 7.7 earthquake triggered a substantial tsunami that killed 600 people along a 200km stretch of coastline. The earthquake was not reported felt along the coastline. While there was a warning issued by the PTWC, it did not trigger an evacuation warning (Synolakis, 2006). The Indian Ocean Tsunami Warning System announced by UNESCO as operational in a press release two weeks before the event did not function as promised. There were no seismic recordings transmitted to the PTWC, and two German tsunameter buoys had broken off their moorings and were not operational. Lifeguards along a tourist beach reported that while the observed the harbinger shoreline recession, they attributed to exteme storm waves that were pounding the beaches that day. Had the tsunami struck on the preceding Sunday, instead of Monday, the death toll would had been far higher. The International Tsunami Survey Team (ITST) surveyed the coastline measuring runup, inundation, flow depths and sediment deposition, with standard methods (Synolakis and Okal, 2004). Runup values ranged up to 21m with several readings over 10m, while sand sheets up to 15cm were deposited. The parent earthquake was similar, albeit of smaller magnitude, to the 1994 East Javan tsunami, which struck about 200km east (Synolakis, et al, 1995) and reached a maximum of 11m runup height only at one location on steep cliffs. The unusual distribution of runup heights, and the pronounced extreme values near Nusa Kambangan, suggest a local coseismic landslide may have triggered an additional tsunami (Okal and Synolakis, 2005). The ITST observed that many coastal villages were completely abandoned after the tsunami, even in locales where there were no casualties. Whether residents will return is uncertain, but it is clear that an education campaign in tsunami hazard mitigation is urgently needed. In the aftermath of the tsunami, the Government of Indonesia enforced urgent emergency preparedness measures, including sirens, identification of rapid evacuation routes, and emergency drills, which were under way some locations the team visited. Synolakis, C.E., What went wrong Wall Street Journal. p. 12, July 25, 2006. Synolakis, C.E., and E.A. Okal, 1992--2002: Perspective on a decade of post-tsunami surveys, in: Tsunamis: Case studies, K. Satake (ed), Adv. Natur. Technol. Hazards, 23 1--30, 2005. Okal, E.A., and Synolakis, C.E., Source discriminants for nearfield tsunamis, Geophysical Journal International, 158, 899?-912, 2004. Synolakis, C.E., Imamura, F., Tsuji, Y., Matsutomi, S., Tinti, B., Cook, B., and Ushman, M. Damage, Conditions of East Java tsunami of 1994 analyzed, EOS, 76, (26), 257 and 261-?262, 1995.

Tsunami prevention and mitigation necessities and options derived from tsunami risk assessment in Indonesia

NASA Astrophysics Data System (ADS)

Post, J.; Zosseder, K.; Wegscheider, S.; Steinmetz, T.; Mück, M.; Strunz, G.; Riedlinger, T.; Anwar, H. Z.; Birkmann, J.; Gebert, N.

2009-04-01

Risk and vulnerability assessment is an important component of an effective End-to-End Tsunami Early Warning System and therefore contributes significantly to disaster risk reduction. Risk assessment is a key strategy to implement and design adequate disaster prevention and mitigation measures. The knowledge about expected tsunami hazard impacts, exposed elements, their susceptibility, coping and adaptation mechanisms is a precondition for the development of people-centred warning structures, local specific response and recovery policy planning. The developed risk assessment and its components reflect the disaster management cycle (disaster time line) and cover the early warning as well as the emergency response phase. Consequently the components hazard assessment, exposure (e.g. how many people/ critical facilities are affected?), susceptibility (e.g. are the people able to receive a tsunami warning?), coping capacity (are the people able to evacuate in time?) and recovery (are the people able to restore their livelihoods?) are addressed and quantified. Thereby the risk assessment encompasses three steps: (i) identifying the nature, location, intensity and probability of potential tsunami threats (hazard assessment); (ii) determining the existence and degree of exposure and susceptibility to those threats; and (iii) identifying the coping capacities and resources available to address or manage these threats. The paper presents results of the research work, which is conducted in the framework of the GITEWS project and the Joint Indonesian-German Working Group on Risk Modelling and Vulnerability Assessment. The assessment methodology applied follows a people-centred approach to deliver relevant risk and vulnerability information for the purposes of early warning and disaster management. The analyses are considering the entire coastal areas of Sumatra, Java and Bali facing the Sunda trench. Selected results and products like risk maps, guidelines, decision support information and other GIS products will be presented. The focus of the products is on the one hand to provide relevant risk assessment products as decision support to issue a tsunami warning within the early warning stage. On the other hand the maps and GIS products shall provide relevant information to enable local decision makers to act adequately concerning their local risks. It is shown that effective prevention and mitigation measures can be designed based on risk assessment results and information especially when used pro-active and beforehand a disaster strikes. The conducted hazard assessment provides the probability of an area to be affected by a tsunami threat divided into two ranked impact zones. The two divided impact zones directly relate to tsunami warning levels issued by the Early Warning Center and consequently enable the local decision maker to base their planning (e.g. evacuation) accordingly. Within the tsunami hazard assessment several hundred pre-computed tsunami scenarios are analysed. This is combined with statistical analysis of historical event data. Probabilities of tsunami occurrence considering probabilities of different earthquake magnitudes, occurrences of specific wave heights at coast and spatial inundation probability are computed. Hazard assessment is then combined with a comprehensive vulnerability assessment. Here deficits in e.g. people's ability to receive and understand a tsunami warning and deficits in their ability to respond adequately (evacuate on time) are quantified and are visualized for the respective coastal areas. Hereby socio-economic properties (determining peoples ability to understand a warning and to react) are combined with environmental conditions (land cover, slope, population density) to calculate the time needed to evacuate (reach a tsunami safe area derived through the hazard assessment). This is implemented using a newly developed GIS cost-distance weighting approach. For example, the amount of people affected in a certain area is dependent on expected tsunami intensity, inundated area, estimated tsunami arrival time and available time for evacuation. Referring to the Aceh 2004 Tsunami, an estimated amount of people affected (dead/injured) of 21000 for Kabubaten Aceh Jaya and 85000 for Kab. Banda Aceh is in a comparable range with reported values of 19661 and 78417 (JICA 2005) respectively. Hence the established methodology provides reliable estimates of people affected and people's ability to reach a safe area. Based on the spatial explicit detection of e.g. high tsunami risk areas (and the assessed root causes therefore), specific disaster risk reduction and early warning strategies can be designed. For example additional installation of technical warning dissemination device, community based preparedness and awareness programmes (education), structural and non-structural measures (e.g. land use conversion, coastal engineering), effective evacuation, contingency and household recovery aid planning can be employed and/or optimized within high tsunami risk areas as a first priority. In the context of early warning, spatially distributed information like degree of expected hazard impact, exposure of critical facilities (e.g. hospitals, schools), potential people dead/injured depending on available response times, location of safe and shelter areas can be disseminated and used for decision making. Keywords: Tsunami risk, hazard and vulnerability assessment, early warning, tsunami mitigation and prevention, Indonesia

Lessons Learned and Unlearned from the 2004 Great Sumatran Tsunami.

NASA Astrophysics Data System (ADS)

Synolakis, C.; Kanoglu, U.

2014-12-01

Huppert & Sparks (2006 Phil Trans Math Phys Eng Sci) wrote It is likely that in the future, we will experience several disasters per year that kill more than 10,000 people. The 2011 Great East Japan Earthquake Disaster alone resulted in more than 20,000 casualties. Synolakis & Bernard (2006 Phil Trans Math Phys Eng Sci) concluded that Before the next Sumatra-type tsunami strikes, we must resolve to create a world that can coexist with the tsunami hazard. The 2011 Japan tsunami dramatically showed that we are not there yet. Despite substantial advances after the 2004 Boxing Day tsunami, substantial challenges remain for improving tsunami hazard mitigation. If the tsunami community appeared at first perplexed in the aftermath of the 2004 tsunami, it was not due to the failure of recognized hydrodynamic paradigms, much as certain geophysical ones and scaling laws failed, but at the worst surprise, the lack of preparedness and education. Synolakis et al. (2008 Pure Appl Geophys) presented standards for tsunami modeling; for both warnings and inundation maps (IMs). Although at least one forecasting methodology has gone through extensive testing, and is now officially in use by the warning centers (WCs), standards need urgently to be formalized for warnings. In Europe, several WCs have been established, but none has yet to issue an operational warning for a hazardous event. If it happens, there might be confusion with possibly contradictory/competing warnings. Never again should there be a repeat of the TEPCO analysis for the safety of the Fukushima NPP. This was primarily due to lacks of familiarity with the context of numerical predictions and experience with real tsunami. The accident was the result of a cascade of stupid errors, almost impossible to ignore by anyone in the field (Synolakis, 26.03.2011 The New York Times). Current practices in tsunami studies for US NPPs and for IMs do not provide us with optimism that the Fukushima lessons have been absorbed and that bagatellomania is still rabid. What saves human lives is ancestral knowledge and community preparedness, as demonstrated repeatedly. Efforts need to be focused in improving education worldwide in the simple steps they can take. We acknowledge the partial supports from the 7th FP (ASTARTE, Grant 603839), TUBITAK, TR (109Y387) and GSRT, GR (10TUR/1-50-1) projects.

The potential role of real-time geodetic observations in tsunami early warning

NASA Astrophysics Data System (ADS)

Tinti, Stefano; Armigliato, Alberto

2016-04-01

Tsunami warning systems (TWS) have the final goal to launch a reliable alert of an incoming dangerous tsunami to coastal population early enough to allow people to flee from the shore and coastal areas according to some evacuation plans. In the last decade, especially after the catastrophic 2004 Boxing Day tsunami in the Indian Ocean, much attention has been given to filling gaps in the existing TWSs (only covering the Pacific Ocean at that time) and to establishing new TWSs in ocean regions that were uncovered. Typically, TWSs operating today work only on earthquake-induced tsunamis. TWSs estimate quickly earthquake location and size by real-time processing seismic signals; on the basis of some pre-defined "static" procedures (either based on decision matrices or on pre-archived tsunami simulations), assess the tsunami alert level on a large regional scale and issue specific bulletins to a pre-selected recipients audience. Not unfrequently these procedures result in generic alert messages with little value. What usually operative TWSs do not do, is to compute earthquake focal mechanism, to calculate the co-seismic sea-floor displacement, to assess the initial tsunami conditions, to input these data into tsunami simulation models and to compute tsunami propagation up to the threatened coastal districts. This series of steps is considered nowadays too time consuming to provide the required timely alert. An equivalent series of steps could start from the same premises (earthquake focal parameters) and reach the same result (tsunami height at target coastal areas) by replacing the intermediate steps of real-time tsunami simulations with proper selection from a large archive of pre-computed tsunami scenarios. The advantage of real-time simulations and of archived scenarios selection is that estimates are tailored to the specific occurring tsunami and alert can be more detailed (less generic) and appropriate for local needs. Both these procedures are still at an experimental or testing stage and haven't been implemented yet in any standard TWS operations. Nonetheless, this is seen to be the future and the natural TWS evolving enhancement. In this context, improvement of the real-time estimates of tsunamigenic earthquake focal mechanism is of fundamental importance to trigger the appropriate computational chain. Quick discrimination between strike-slip and thrust-fault earthquakes, and equally relevant, quick assessment of co-seismic on-fault slip distribution, are exemplary cases to which a real-time geodetic monitoring system can contribute significantly. Robust inversion of geodetic data can help to reconstruct the sea floor deformation pattern especially if two conditions are met: the source is not too far from network stations and is well covered azimuthally. These two conditions are sometimes hard to satisfy fully, but in certain regions, like the Mediterranean and the Caribbean sea, this is quite possible due to the limited size of the ocean basins. Close cooperation between the Global Geodetic Observing System (GGOS) community, seismologists, tsunami scientists and TWS operators is highly recommended to obtain significant progresses in the quick determination of the earthquake source, which can trigger a timely estimation of the ensuing tsunami and a more reliable and detailed assessment of the tsunami size at the coast.

Tsunami-Generated Atmospheric Gravity Waves and Their Atmospheric and Ionospheric Effects: a Review and Some Recent Modeling Results

NASA Astrophysics Data System (ADS)

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.

PTWC Creating a New Catalog of Historic Tsunami Animations for NOAA Science-on-a-Sphere Exhibits

NASA Astrophysics Data System (ADS)

Becker, N. C.; Geschwind, L. R.; Wang, D.

2016-12-01

Throughout 2016 the Pacific Tsunami Warning Center (PTWC) has been developing a catalog of tsunami animations for NOAA's Science on a Sphere (SOS) display system. The SOS consists of a six-foot (1.8 m) diameter sphere that serves as a projection screen for four high-definition video projectors that can show any global dataset. SOS systems have been installed in over 100 locations around the world, primarily in venues such as science museums. Education and outreach are a vital part of PTWC's mission and SOS can show the global impacts of tsunami hazards in an intuitive and engaging presentation analogous to a planetarium. PTWC has been releasing these animations for the anniversaries of significant tsunamis throughout the year and has so far has produced them for Cascadia 1700, Chile 2010, Japan 2011, Aleutian Islands 1946, Alaska 1964, and Chile 1960, and before the end of the year the library will include Samoa 2009 and Sumatra 2004. PTWC created these animations at 8k video resolution to future-proof them against SOS upgrades such as higher definition projectors and larger spheres. Though not the first SOS tsunami animations, these are the first ones to show impacts to coastlines, the criteria that PTWC uses to determine the tsunami hazard guidance it will issue to the coastal populations it serves. These animations also all use a common color scheme based on PTWC's alert criteria such that they will be consistent with each other as well as with PTWC's tsunami messages. PTWC created these animations using the same tsunami forecast model it routinely uses in its warning operations, and PTWC has even demonstrated that it can produce a SOS tsunami animation while a tsunami was still crossing the Pacific Ocean, and so this library of animations can also be used to prepare docents and audiences to interpret such a real-time animation should it become available for the next major tsunami. One does not need access to a SOS exhibit, however, to view these animations. NOAA also maintains a website where these animations can be viewed in a web browser. The site also allows a user to download these data along with software such that they may be viewed on a personal computer. PTWC also maintains a YouTube channel with Mercator-projected versions of these animations that are in the same style and color scheme as their SOS counterparts.

Seismic structure of subducted Philippine Sea plate beneath the southern Ryukyu arc by receiver function and local earthquakes tomography

NASA Astrophysics Data System (ADS)

Nakamura, M.

2012-12-01

Seismic coupling of the Ryukyu subduction zone is assumed to be weak from the lack of historical interplate large earthquakes. However, recent investigation of repeating slow slip events (Heki & Kataoka, 2008), shallow low frequency earthquakes (Ando et al., 2012), and source of 1771 Yaeyama mega-tsunami (Nakamura, 2009), showed that the interplate coupling is not weak in the south of Ryukyu Trench. The biannually repeating SSEs (Mw=6.5) occur at the depth of 20-40 km on the upper interface of the subducted Philippine Sea plate beneath Yaeyama region, where earthquake swarm occurred on 1991 and 1992. To reveal the relation among the crustal structure, earthquake swarms, and occurrence of slow slip events (SSE), local earthquake tomography and receiver function (RF) analysis was computed in the southwestern Ryukyu arc. A tomographic inversion was used to determine P and S wave structures beneath Iriomote Island in the southwestern Ryukyu region for comparison with the locations of the SSE. The seismic tomography (Thurber & Eberhart-Phillips, 1999) was employed. The P- and S- wave arrival time data picked manually by Japan Meteorological Agency (JMA) are used. The 6750 earthquakes from January 2000 to July 2012 were used. For the calculation of the receiver function, the 212 earthquakes whose magnitudes are over 6.0 and epicentral distances are between 30 and 90 degrees were selected. The teleseicmic waveforms observed at two short-period seismometers of the JMA, and one broadband seismometer of F-net of National Research Institute for Earth Science and Disaster Prevention were used. The water level method (the water level is 0.01) is applied to original waveforms. Assuming that each later phase in a RF is the wave converted from P to S at a depth, I transformed the time domain RF into the depth domain one along each ray path in a reference velocity model. The JMA2001 velocity model is used in this study. The results of tomography show that the low Vp and high Vp/Vs anomalies are distributed along the hypocenters in the subducted slab. The plate interface is about 10 km above the slab earthquakes from the trace of negative RF amplitude. The slab earthquakes are distributed along the trace of positive RF amplitude. Therefore the slab earthquakes occur near the oceanic Moho of the PHS. The fault depth of the SSEs corresponds to the plate interface within 5 km. The fault-planes of the SSE are located above the low Vp and high Vp/Vs zone. Assuming that the difference between high Vp/Vs and low Vp/Vs originates to the fluid contents, this would be interpreted that the fluids from the subducted oceanic crust cannot be transported upward and is trapped at the plate interface. The observed strong S-wave reflector (Nakamura, 2001) in the upper interface of the subducted plate also supports the idea. The top of the faults of the SSEs connects to the cluster of earthquake swarms in the lower crust. This suggests that the trapped fluids are transported upward along the faults, accumulates in the lower crust, and induce the swarm of micro-earthquakes in the lower crust.

Tsunami overview.

PubMed

Morrow, Robert C; Llewellyn, D Mark

2006-10-01

Historically, floods and tsunamis have caused relatively few severe injuries; an exception to that tendency followed the great Andaman Island-Sumatra earthquake and tsunami of 2004. More than 280,000 people died, the coastal plains were massively scoured, and more than 1 million individuals were made homeless by the quake and resulting tsunami, which affected a 10-nation region around the Indian Ocean. This destruction overwhelmed local resources and called forth an unprecedented, prolonged, international response. The USNS Mercy deployed on a unique mission and rendered service to the people and government of Indonesia. This introduction provides background on the nature and extent of the damage, conditions upon arrival of the hospital ship 5 weeks after the initial destruction, and the configuration of professionals aboard (officers and sailors of the U.S. Navy, civilian volunteers from Project HOPE, officers of the U.S. Public Health Service, and officers and civilian mariners of the Military Sealift Command). Constraints on the mission provide context for the other articles of this issue that document and comment on the activities, challenges, methods, and accomplishments of this unique mission's "team of teams," performing humanitarian assistance and disaster relief in the Pacific theater.

TIDE TOOL: Open-Source Sea-Level Monitoring Software for Tsunami Warning Systems

NASA Astrophysics Data System (ADS)

Weinstein, S. A.; Kong, L. S.; Becker, N. C.; Wang, D.

2012-12-01

A tsunami warning center (TWC) typically decides to issue a tsunami warning bulletin when initial estimates of earthquake source parameters suggest it may be capable of generating a tsunami. A TWC, however, relies on sea-level data to provide prima facie evidence for the existence or non-existence of destructive tsunami waves and to constrain tsunami wave height forecast models. In the aftermath of the 2004 Sumatra disaster, the International Tsunami Information Center asked the Pacific Tsunami Warning Center (PTWC) to develop a platform-independent, easy-to-use software package to give nascent TWCs the ability to process WMO Global Telecommunications System (GTS) sea-level messages and to analyze the resulting sea-level curves (marigrams). In response PTWC developed TIDE TOOL that has since steadily grown in sophistication to become PTWC's operational sea-level processing system. TIDE TOOL has two main parts: a decoder that reads GTS sea-level message logs, and a graphical user interface (GUI) written in the open-source platform-independent graphical toolkit scripting language Tcl/Tk. This GUI consists of dynamic map-based clients that allow the user to select and analyze a single station or groups of stations by displaying their marigams in strip-chart or screen-tiled forms. TIDE TOOL also includes detail maps of each station to show each station's geographical context and reverse tsunami travel time contours to each station. TIDE TOOL can also be coupled to the GEOWARE™ TTT program to plot tsunami travel times and to indicate the expected tsunami arrival time on the marigrams. Because sea-level messages are structured in a rich variety of formats TIDE TOOL includes a metadata file, COMP_META, that contains all of the information needed by TIDE TOOL to decode sea-level data as well as basic information such as the geographical coordinates of each station. TIDE TOOL can therefore continuously decode theses sea-level messages in real-time and display the time-series data in the GUI as well. This GUI also includes mouse-clickable functions such as zooming or expanding the time-series display, measuring tsunami signal characteristics (arrival time, wave period and amplitude, etc.), and removing the tide signal from the time-series data. De-tiding of the time series is necessary to obtain accurate measurements of tsunami wave parameters and to maintain accurate historical tsunami databases. With TIDE TOOL, de-tiding is accomplished with a set of tide harmonic coefficients routinely computed and updated at PTWC for many of the stations in PTWC's inventory (~570). PTWC also uses the decoded time series files (previous 3-5 days' worth) to compute on-the-fly tide coefficients. The latter is useful in cases where the station is new and a long-term stable set of tide coefficients are not available or cannot be easily obtained due to various non-astronomical effects. The international tsunami warning system is coordinated globally by the UNESCO IOC, and a number of countries in the Pacific and Indian Ocean, and Caribbean depend on Tide Tool to monitor tsunamis in real time.

The Hellenic National Tsunami Warning Centre (HL-NTWC): Recent updates and future developments

NASA Astrophysics Data System (ADS)

Melis, Nikolaos S.; Charalampakis, Marinos

2014-05-01

The Hellenic NTWC (HL-NTWC) was established officially by Greek Law in September 2010. HL-NTWC is hosted at the National Observatory of Athens, Institute of Geodynamics (NOA-IG), which also operates a 24/7 earthquake monitoring service in Greece and coordinates the newly established Hellenic Unified National Seismic Network. NOA-IG and HL-NTWC Operational Centre is linked to the Civil Protection Operational Centre and serves as the official alerting agency to the General Secretariat for Civil Protection in Greece, regarding earthquake events and tsunami watch. Since August 2012, HL-NTWC acts as Candidate Tsunami Watch Provider (CTWP) under the UNESCO IOC - ICG NEAMTWS tsunami warning system (NEAM: North-Eastern Atlantic, the Mediterranean and connected seas) and offers its services to the NEAMTWS system. HL-NTWC has participated in all Communication Test Exercises (CTE) under NEAMTWS and also it has provided tsunami scenarios for extended system testing exercises such as NEAMWAVE12. Some of the recent developments at HL-NTWC in Greece include: deployment of new tide gauge stations for tsunami watch purposes, computation of tsunami scenarios and extending the database in use, improving alerting response times, earthquake magnitude estimation and testing newly established software modules for tsunami and earthquake alerting (i.e. Early-Est, SeisComP3 etc.) in Greece and the Eastern Mediterranean. Although funding today is limited, an advantage of the participation in important EC funded research projects, i.e. NERIES, NERA, TRANSFER, NEAMTIC and ASTARTE, demonstrates that collaboration of top class Research Institutions that care to produce important and useful results in the research front in Europe, can facilitate towards developing and operating top class Operational Centers, useful for Civil Protection purposes in regions in need. Last, it is demonstrated that HL-NTWC collaboration with important key role Research Centers in the Security and Safety issues (e.g. JRC-IPSC) at the Operational front, can further facilitate and secure everyday operation under a collaborative and experience exchanging manner. This work is funded by project ASTARTE - Assessment, STrategy And Risk Reduction for Tsunamis in Europe. Grant 603839, 7th FP (ENV.2013.6.4-3 ENV.2013.6.4-3)

Rapid processing of data based on high-performance algorithms for solving inverse problems and 3D-simulation of the tsunami and earthquakes

NASA Astrophysics Data System (ADS)

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 create technology «no frost», realizing a steady stream of direct and inverse problems: solving the direct problem, the visualization and comparison with observed data, to solve the inverse problem (correction of the model parameters). The main objective of further work is the creation of a workstation operating emergency tool that could be used by an emergency duty person in real time.

Quantifying the impacts of global disasters

NASA Astrophysics Data System (ADS)

Jones, L. M.; Ross, S.; Wilson, R. I.; Borrero, J. C.; Brosnan, D.; Bwarie, J. T.; Geist, E. L.; Hansen, R. A.; Johnson, L. A.; Kirby, S. H.; Long, K.; Lynett, P. J.; Miller, K. M.; Mortensen, C. E.; Perry, S. C.; Porter, K. A.; Real, C. R.; Ryan, K. J.; Thio, H. K.; Wein, A. M.; Whitmore, P.; Wood, N. J.

2012-12-01

The US Geological Survey, National Oceanic and Atmospheric Administration, California Geological Survey, and other entities are developing a Tsunami Scenario, depicting a realistic outcome of a hypothetical but plausible large tsunami originating in the eastern Aleutian Arc, affecting the west coast of the United States, including Alaska and Hawaii. The scenario includes earth-science effects, damage and restoration of the built environment, and social and economic impacts. Like the earlier ShakeOut and ARkStorm disaster scenarios, the purpose of the Tsunami Scenario is to apply science to quantify the impacts of natural disasters in a way that can be used by decision makers in the affected sectors to reduce the potential for loss. Most natural disasters are local. A major hurricane can destroy a city or damage a long swath of coastline while mostly sparing inland areas. The largest earthquake on record caused strong shaking along 1500 km of Chile, but left the capital relatively unscathed. Previous scenarios have used the local nature of disasters to focus interaction with the user community. However, the capacity for global disasters is growing with the interdependency of the global economy. Earthquakes have disrupted global computer chip manufacturing and caused stock market downturns. Tsunamis, however, can be global in their extent and direct impact. Moreover, the vulnerability of seaports to tsunami damage can increase the global consequences. The Tsunami Scenario is trying to capture the widespread effects while maintaining the close interaction with users that has been one of the most successful features of the previous scenarios. The scenario tsunami occurs in the eastern Aleutians with a source similar to the 2011 Tohoku event. Geologic similarities support the argument that a Tohoku-like source is plausible in Alaska. It creates a major nearfield tsunami in the Aleutian arc and peninsula, a moderate tsunami in the US Pacific Northwest, large but not the maximum in Hawaii, and the largest plausible tsunami in southern California. To support the analysis of global impacts, we begin with the Ports of Los Angeles and Long Beach which account for >40% of the imports to the United States. We expand from there throughout California for the first level economic analysis. We are looking to work with Alaska and Hawaii, especially on similar economic issues in ports, over the next year and to expand the analysis to consideration of economic interactions between the regions.

A Preliminary Tsunami Vulnerability Analysis for Yenikapi Region in Istanbul

NASA Astrophysics Data System (ADS)

Ceren Cankaya, Zeynep; Suzen, Lutfi; Cevdet Yalciner, Ahmet; Kolat, Cagil; Aytore, Betul; Zaytsev, Andrey

2015-04-01

One of the main requirements during post disaster recovery operations is to maintain proper transportation and fluent communication at the disaster areas. Ports and harbors are the main transportation hubs which must work with proper performance at all times especially after the disasters. Resilience of coastal utilities after earthquakes and tsunamis have major importance for efficient and proper rescue and recovery operations soon after the disasters. Istanbul is a mega city with its various coastal utilities located at the north coast of the Sea of Marmara. At Yenikapi region of Istanbul, there are critical coastal utilities and vulnerable coastal structures and critical activities occur daily. Fishery ports, commercial ports, small craft harbors, passenger terminals of intercity maritime transportation, water front commercial and/or recreational structures are some of the examples of coastal utilization which are vulnerable against marine disasters. Therefore their vulnerability under tsunami or any other marine hazard to Yenikapi region of Istanbul is an important issue. In this study, a methodology of vulnerability analysis under tsunami attack is proposed with the applications to Yenikapi region. In the study, high resolution (1m) GIS database of Istanbul Metropolitan Municipality (IMM) is used and analyzed by using GIS implementation. The bathymetry and topography database and the vector dataset containing all buildings/structures/infrastructures in the study area are obtained for tsunami numerical modeling for the study area. GIS based tsunami vulnerability assessment is conducted by applying the Multi-criteria Decision Making Analysis (MCDA). The tsunami parameters from deterministically defined worst case scenarios are computed from the simulations using tsunami numerical model NAMI DANCE. The vulnerability parameters in the region due to two different classifications i) vulnerability of buildings/structures and ii) vulnerability of (human) evacuation are defined and scored. The risk level is computed using tsunami intensity (level of flow depth from simulations) and vulnerability (structural and human-based) at each node in Yenikapi. The results are presented at high resolution (1m) and discussed. Acknowledgements: Partial support by EU 603839 ASTARTE Project, UDAP-C-12-14 of AFAD of Turkey, 108Y227 and 113M556 of TUBITAK Turkey, RAPSODI (CONCERT_Dis-021) of CONCERT-Japan Joint Call, 2011K140210 of DPT, Istanbul Metropolitan Municipality, Japan-Turkey Joint Research Project by JICA on earthquakes and tsunamis in Marmara Region by SATREPS are acknowledged.

Tsunami Detection by High-Frequency Radar Beyond the Continental Shelf

NASA Astrophysics Data System (ADS)

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 independent Gaussian distributions. The principle of the new algorithm is to compute correlations of HF radar signals measured/simulated in many pairs of distant "cells" located along the same tsunami wave ray, shifted in time by the tsunami propagation time between these cell locations; both rays and travel time are easily obtained as a function of long wave phase speed and local bathymetry. It is expected that, in the presence of a tsunami current, correlations computed as a function of range and an additional time lag will show a narrow elevated peak near the zero time lag, whereas no pattern in correlation will be observed in the absence of a tsunami current; this is because surface waves and background current are uncorrelated between pair of cells, particularly when time-shifted by the long-wave propagation time. This change in correlation pattern can be used as a threshold for tsunami detection. To validate the algorithm, we first identify key features of tsunami propagation in the Western Mediterranean Basin, where Stradivarius is deployed, by way of direct numerical simulations with a long wave model. Then, for the purpose of validating the algorithm we only model HF radar detection for idealized tsunami wave trains and bathymetry, but verify that such idealized case studies capture well the salient tsunami wave physics. Results show that, in the presence of strong background currents, the proposed method still allows detecting a tsunami with currents as low as 0.05 m/s, whereas a standard direct inversion based on radar signal Doppler spectra fails to reproduce tsunami currents weaker than 0.15-0.2 m/s. Hence, the new algorithm allows detecting tsunami arrival in deeper water, beyond the shelf and further away from the coast, and providing an early warning. Because the standard detection of tsunami currents works well at short range, we envision that, in a field situation, the new algorithm could complement the standard approach of direct near-field detection by providing a warning that a tsunami is approaching, at larger range and in greater depth. This warning would then be confirmed at shorter range by a direct inversion of tsunami currents, from which the magnitude of the tsunami would also estimated. Hence, both algorithms would be complementary. In future work, the algorithm will be applied to actual tsunami case studies performed using a state-of-the-art long wave model, such as briefly presented here in the Mediterranean Basin.

Advanced Geospatial Hydrodynamic Signals Analysis for Tsunami Event Detection and Warning

NASA Astrophysics Data System (ADS)

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 tsunami event in the Pacific Ocean. The new approach will be tested in the future on other oceanic regions including the Mediteranean Sea and North East Atlantic Ocean zones. Both authors acknowledge that the current research is currently conducted under the TRIDEC IP FP7 project[1] which involves the development of a system of systems for collaborative, complex and critical decision-support in evolving crises. [1] TRIDEC IP ICT-2009.4.3 Intelligent Information Management Project Reference: 258723. http://www.tridec-online.eu/home

Usability and Visual Communication for Southern California Tsunami Evacuation Information: The importance of information design in disaster risk management

NASA Astrophysics Data System (ADS)

Jaenichen, C.; Schandler, S.; Wells, M.; Danielsen, T.

2015-12-01

Evacuation behavior, including participation and response, is rarely an individual and isolated process and the outcomes are usually systemic. Ineffective evacuation information can easily attribute to delayed evacuation response. Delays increase demands on already extended emergency personal, increase the likelihood of traffic congestion, and can cause harm to self and property. From an information design perspective, addressing issues in cognitive recall and emergency psychology, this case study examines evacuation messaging including written, audio, and visual presentation of information, and describes the application of design principles and role of visual communication for Southern California tsunami evacuation outreach. The niche of this project is the inclusion of cognitive processing as the driving influence when making formal design decisions and measurable data from a 4-year cognitive recall study to support the solution. Image included shows a tsunami evacaution map before and after the redesign.

The Canadian seasonal forecast and the APCC exchange.

NASA Astrophysics Data System (ADS)

Archambault, B.; Fontecilla, J.; Kharin, V.; Bourgouin, P.; Ashok, K.; Lee, D.

2009-05-01

In this talk, we will first describe the Canadian seasonal forecast system. This system uses a 4 model ensemble approach with each of these models generating a 10 members ensemble. Multi-model issues related to this system will be describes. Secondly, we will describe an international multi-system initiative. The Asia-Pacific Economic Cooperation (APEC) is a forum for 21 Pacific Rim countries or regions including Canada. The APEC Climate Center (APCC) provides seasonal forecasts to their regional climate centers with a Multi Model Ensemble (MME) approach. The APCC MME is based on 13 ensemble prediction systems from different institutions including MSC(Canada), NCEP(USA), COLA(USA), KMA(Korea), JMA(Japan), BOM(Australia) and others. In this presentation, we will describe the basics of this international cooperation.

Japan: Super-Aging Society Preparing for the Future

ERIC Educational Resources Information Center

Muramatsu, Naoko; Akiyama, Hiroko

2011-01-01

Japan has the highest proportion of older adults in the world. Aging is not only an immediate personal issue but also a salient factor in crucial public policies, such as pensions, health, and long-term care. The Great East Japan Earthquake, tsunami, and nuclear power plant disaster of March 2011 has highlighted current and emerging issues of a…

About 500-yr interval of huge and widespread paleotsunamis along the Sanriku coast, northern Honshu, Japan

NASA Astrophysics Data System (ADS)

Haraguchi, T.; Toda, S.; Tsutsumi, H.; Meghraoui, M.; Ferry, M.; Takada, K.

2012-12-01

The 2011 Mw 9.0 Tohoku-oki earthquake triggered a massive tsunami and devastated ~1,000-km-long coastal regions from Aomori to Chiba prefectures, northeast Honshu island. Several pioneering papers already investigated the Sendai to Fukushima region, southern 2011 source area. They found a widespread tsunami inundation by the 869 A.D. Jogan tsunami event (e.g., Minoura and Imamura, 2001; Sawai et al., 2008), which lead the estimated size of the Jogan earthquake up to M8.4 (Satake et al., 2008). No geologic evidence and no historical account in further north may have prevented to conclude straightforwardly that the Jogan earthquake was the penultimate event of the Tohoku-oki earthquake. Here we focus on the Sariku coast, northern part of the 2011 source, and present our pre-Tohoku-oki studies performed at six locations. To recover paleotsunami deposits, I employed conventional coring technique and newly invented Geoslicer to extract several-meter-deep soil and sediment samples. Evidence for paleotsunami event is generally discernible as a several-to-several-tens-of-centimeter medium-to-coarse sand often including mud clast and shells. Such a tsunami sand layer is also distinct intercalated by peats and humic soils representing interseimic dormant periods. Radiocarbon dates yielded from such organic-rich units bracket the depositional timing of the tsunami sand. Although the time constraints of the tsunami sand units are different from site to site, there are shared time ranges of tsunami inundations. Seven well-preserved paleotsunami horizons were commonly found at five onshore sites during the period between 1,000 and 6,000 y.B.P, which yields 500-700 years of recurrence intervals of extremely large tsunamis. One of the flaws in the onshore surveys however is a deficit of the younger sediments due to surface human perturbations. To overcome the issue, I then chose a site inside a bay where no massive erosion and human modification were expected. A 35-m drilling sample recovered from Ozuchi Bay, central Sanriku coast, instead preserved more frequent 22 units of tsunami deposits and associated perturbations during the past 8,000 years, including the 869 A.D. event. It suggests that shoal inside bays can well preserve the sediments of tsunamis, even smaller events. A prominent tendency found in the sequence of tsunami units is a sudden change of recurrence intervals from 500-800 years to 70-150 years at 2,000 y.B.P., which might be associated with a sudden bathymetry change. It may also implies that only huge tsunamis occurred every 500-800 years left sediments inside the bay, which is consistent with the results from onshore surveys.

Frequency Distribution of Seismic Intensity in Japan between 1950 and 2009

NASA Astrophysics Data System (ADS)

Kato, M.; Kohayakawa, Y.

2012-12-01

JMA Seismic Intensity is an index of seismic ground motion which is frequently used and reported in the media. While it is always difficult to represent complex ground motion with one index, the fact that it is widely accepted in the society makes the use of JMA Seismic Intensity preferable when seismologists communicate with the public and discuss hazard assessment and risk management. With the introduction on JMA Instrumental Intensity in 1996, the number of seismic intensity observation sites has substantially increased and the spatial coverage has improved vastly. Together with a long history of non-instrumental intensity records, the intensity data represent some aspects of the seismic ground motion in Japan. We investigate characteristics of seismic ground motion between 1950 and 2009 utilizing JMA Seismic Intensity Database. Specifically we are interested in the frequency distribution of intensity recordings. Observations of large intensity is rare compared to those of small intensity, and previous studies such as Ikegami [1961] demonstrated that frequency distribution of observed intensity obeys an exponential law, which is equivalent to the Ishimoto-Iida law [Ishimoto & Iida, 1939]. Such behavior could be used to empirically construct probabilistic seismic hazard maps [e.g., Kawasumi, 1951]. For the recent instrumental intensity data as well as pre-instrumental data, we are able to confirm that Ishimoto-Iida law explains the observation. Exponents of the Ishimoto-Iida law, or slope of the exponential law in the semi-log plot, is approximately 0.5. At stations with long recordings, there is no apparent difference between pre-instrumental and instrumental intensities when Ishimoto-Iida law is used as a measure. Numbers of average intensity reports per year and exponents of the frequency distribution curve vary regionally and local seismicity is apparently the controlling factor. The observed numbers of large intensity is slightly less than extrapolated and predicted from those of small intensity assuming the exponential relation.

JMA's regional atmospheric transport model calculations for the WMO technical task team on meteorological analyses for Fukushima Daiichi Nuclear Power Plant accident.

PubMed

Saito, Kazuo; Shimbori, Toshiki; Draxler, Roland

2015-01-01

The World Meteorological Organization (WMO) convened a small technical task team of experts to produce a set of meteorological analyses to drive atmospheric transport, dispersion and deposition models (ATDMs) for the United Nations Scientific Committee on the Effects of Atomic Radiation's assessment of the Fukushima Daiichi Nuclear Power Plant (DNPP) accident. The Japan Meteorological Agency (JMA) collaborated with the WMO task team as the regional specialized meteorological center of the country where the accident occurred, and provided its operational 5-km resolution mesoscale (MESO) analysis and its 1-km resolution radar/rain gauge-analyzed precipitation (RAP) data. The JMA's mesoscale tracer transport model was modified to a regional ATDM for radionuclides (RATM), which included newly implemented algorithms for dry deposition, wet scavenging, and gravitational settling of radionuclide aerosol particles. Preliminary and revised calculations of the JMA-RATM were conducted according to the task team's protocol. Verification against Cesium 137 ((137)Cs) deposition measurements and observed air concentration time series showed that the performance of RATM with MESO data was significantly improved by the revisions to the model. The use of RAP data improved the (137)Cs deposition pattern but not the time series of air concentrations at Tokai-mura compared with calculations just using the MESO data. Sensitivity tests of some of the more uncertain parameters were conducted to determine their impacts on ATDM calculations, and the dispersion and deposition of radionuclides on 15 March 2011, the period of some of the largest emissions and deposition to the land areas of Japan. The area with high deposition in the northwest of Fukushima DNPP and the hotspot in the central part of Fukushima prefecture were primarily formed by wet scavenging influenced by the orographic effect of the mountainous area in the west of the Fukushima prefecture. Copyright © 2014 The Authors. Published by Elsevier Ltd.. All rights reserved.

Tsunami hazard assessment in La Reunion and Mayotte Islands in the Indian Ocean : detailed modeling of tsunami impacts for the PREPARTOI project

NASA Astrophysics Data System (ADS)

Quentel, E.; Loevenbruck, A.; Sahal, A.; Lavigne, F.

2011-12-01

Significant tsunamis have often affected the southwest Indian Ocean. The scientific project PREPARTOI (Prévention et REcherche pour l'Atténuation du Risque Tsunami dans l'Océan Indien), partly founded by the MAIF foundation, aims at assessing the tsunami risk on both french islands of this region, La Réunion and Mayotte. Further purpose of this project is the detailed hazard and vulnerability study for specific places of these islands, selected according to their environmental and human issues and observed impacts of past tsunamis. Tsunami hazard in this region, recently highlighted by major events in the southwest Indian Ocean, has never been thoroughly evaluated. Our study, within the PREPARTOI project, contributes to fill in this lack. It aims at examining transoceanic tsunami hazard related to earthquakes by modeling the scenarios of major historical events. We consider earthquakes with magnitude greater than Mw 7.7 located on the Sumatra (1833, 2004, 2010), Java (2006) and Makran (1945) subduction zones. First, our simulations allow us to compare the tsunami impact at regional scale according to the seismic sources; we thus identify earthquakes locations which most affect the islands and describe the impact distribution along their coastline. In general, we note that, for the same magnitude, events coming from the southern part of Sumatra subduction zone induce a larger impact than the north events. The studied tsunamis initiated along the Java and Makran subduction zones have limited effects on both French islands. Then, detailed models for the selected sites are performed based on high resolution bathymetric and topographic data; they provide estimations of the water currents, the water heights and the potential inundations. When available, field measurements and maregraphic records allow testing our models. Arrival time, amplitude of the first wave and impact on the tide gauge time series are well reproduced. Models are consistent with the observations. During historical tsunamis events, Mayotte registered important run-up along its coasts (between 3 and 4.4 m for the 2004 event). In La Réunion, the west coast is the most affected (to 2.7 m in the harbor of La Possession for 2004 event) by transoceanic tsunamis. For example, selected sites situated along the West coast of La Réunion are significantly impacted. Simulations have been performed at St Paul; the low topography of this town could make it particularly vulnerable to tsunami waves. Harbors, particularly prone to undergo significant damages, are also examined. The harbors of La Pointe des Galets and La Possession, respectively west and east of the town of Le Port, are studied in details in order to characterize and quantify potential large waves and strong currents. Outside the harbors as well as at Saint Paul, inundations are predicted along the coastline due to important local water heights (> 2.5 m).

Tsunami Warning Services for the U.S. and Canadian Atlantic Coasts

NASA Astrophysics Data System (ADS)

Whitmore, P. M.; Knight, W.

2008-12-01

In January 2005, the National Oceanic and Atmospheric Administration (NOAA) developed a tsunami warning program for the U.S. Atlantic and Gulf of Mexico coasts. Within a year, this program extended further to the Atlantic coast of Canada and the Caribbean Sea. Warning services are provided to U.S. and Canadian coasts (including Puerto Rico and the Virgin Islands) by the NOAA/West Coast and Alaska Tsunami Warning Center (WCATWC) while the NOAA/Pacific Tsunami Warning Center (PTWC) provides services for non-U.S. entities in the Caribbean Basin. The Puerto Rico Seismic Network (PRSN) is also an active partner in the Caribbean Basin warning system. While the nature of the tsunami threat in the Atlantic Basin is different than in the Pacific, the warning system philosophy is similar. That is, initial messages are based strictly on seismic data so that information is provided to those at greatest risk as fast as possible while supplementary messages are refined with sea level observations and forecasts when possible. The Tsunami Warning Centers (TWCs) acquire regional seismic data through many agencies, such as the United States Geological Survey, Earthquakes Canada, regional seismic networks, and the PRSN. Seismic data quantity and quality are generally sufficient throughout most of the Atlantic area-of-responsibility to issue initial information within five minutes of origin time. Sea level data are mainly provided by the NOAA/National Ocean Service. Coastal tide gage coverage is generally denser along the Atlantic coast than in the Pacific. Seven deep ocean pressure sensors (DARTs), operated by the National Weather Service (NWS) National Data Buoy Center, are located in the Atlantic Basin (5 in the Atlantic Ocean, 1 in the Caribbean, and 1 in the Gulf of Mexico). The DARTs provide TWCs with the means to verify tsunami generation in the Atlantic and provide critical data with which to calibrate forecast models. Tsunami warning response criteria in the Atlantic Basin poses a challenge due to the lack of historic events. The probability and nature of potential sources along the offshore U.S./Canada region are not well understood. Warning/watch/advisory criteria are under review to improve TWC response. Primary tsunami warning contact points consist of NWS Weather Forecast Offices, state warning points, U.S. Coast Guard, and the military. These entities each have responsibility to propagate the message through specific channels. To help communities prepare for a tsunami warning, the NWS established the TsunamiReady program. TsunamiReady sets criteria for communities which include: reliable methods to receive TWC warnings, reliable methods to disseminate messages locally, pre-event planning, hazard/safe zones defined and public education. Once the criteria are met, the community can be recognized as TsunamiReady. A hypothetical event off the east coast is examined and a timeline given for TWC analysis and product issuance.

The November 17, 2015 Lefkada offshore (non-?)tsunamigenic earthquake: preliminary considerations and implications for tsunami hazard and warning in the Ionian Sea

NASA Astrophysics Data System (ADS)

Armigliato, Alberto; Tinti, Stefano; Pagnoni, Gianluca; Ausilia Paparo, Maria; Zaniboni, Filippo

2016-04-01

A Mw = 6.5 earthquake occurred on November 17, 2015 just offshore the western coast of the Ionian island of Lefkada (western Greece). The earthquake caused two fatalities and severe damage, especially in the island of Lefkada. Several landslides were set in motion by the earthquake, some of which occurred along the coastal cliffs. The earthquake was clearly felt also along the eastern coasts of Apulia, Calabria and Sicily (Italy). The computed focal mechanisms indicate that the rupture occurred along a dextral strike-slip, sub-vertical fault, compatible with the well-known transcurrent tectonics of the Lefkada-Cephalonia area. At the time of the drafting of this abstract no heterogeneous slip distribution has been proposed. No clear evidence of tsunami effects is available, with the only exception of the signal recorded by the tide gauge in Crotone (eastern Calabria, Italy), where a clear disturbance (still to be fully characterised and explained) emerges from the background at approximately 1 hour after the earthquake origin time. From the tsunami research point of view, the November 17 Lefkada earthquake poses at least two problems, which we try to address in this paper. The first consists in studying the tsunami generation based on the available seismic information and on the tectonic setting of the area. We present results of numerical simulations of the tsunami generation and propagation aimed at casting light on the reasons why the generated tsunami was so weak (or even absent). Starting from the official fault parameters provided by the seismic agencies, we vary a number of them, there including the length and width calculated on the basis of different regression formulas, and the depth. For each configuration we perform tsunami simulations by means of the in-house finite-difference code UBO-TSUFD. In parallel, we analyse the Crotone tide-gauge record in order to understand whether the observed "anomalous" signal can be attributed to a tsunami or not. In the first case we will try at least to reproduce the observed signal, otherwise we will try to understand whether the non-tsunamigenic nature of the event is confirmed by the tsunami simulations. The second problem is more related to tsunami early warning issues, in particular with the performance of the Tsunami Decision Matrix for the Mediterranean, presently adopted for example by the candidate Tsunami Service Providers at NOA (Greece) and INGV (Italy). We will briefly discuss whether the present form of the matrix, which does not include any information on focal mechanism, is well suited to a peculiar event like the November 17 earthquake, which was of strike-slip nature and had a magnitude lying just at the border between two distinct classes of tsunami potential forecast. This study is funded in the frame of the EU Project called ASTARTE - "Assessment, STrategy And Risk Reduction for Tsunamis in Europe", Grant 603839, 7th FP (ENV.2013.6.4-3), and of the Italian Flagship Project RITMARE ("La Ricerca ITaliana per il MARE").

The virtual craniofacial patient: 3D jaw modeling and animation.

PubMed

Enciso, Reyes; Memon, Ahmed; Fidaleo, Douglas A; Neumann, Ulrich; Mah, James

2003-01-01

In this paper, we present new developments in the area of 3D human jaw modeling and animation. CT (Computed Tomography) scans have traditionally been used to evaluate patients with dental implants, assess tumors, cysts, fractures and surgical procedures. More recently this data has been utilized to generate models. Researchers have reported semi-automatic techniques to segment and model the human jaw from CT images and manually segment the jaw from MRI images. Recently opto-electronic and ultrasonic-based systems (JMA from Zebris) have been developed to record mandibular position and movement. In this research project we introduce: (1) automatic patient-specific three-dimensional jaw modeling from CT data and (2) three-dimensional jaw motion simulation using jaw tracking data from the JMA system (Zebris).

Quantifying human response capabilities towards tsunami threats at community level

NASA Astrophysics Data System (ADS)

Post, J.; Mück, M.; Zosseder, K.; Wegscheider, S.; Taubenböck, H.; Strunz, G.; Muhari, A.; Anwar, H. Z.; Birkmann, J.; Gebert, N.

2009-04-01

Decision makers at the community level need detailed information on tsunami risks in their area. Knowledge on potential hazard impact, exposed elements such as people, critical facilities and lifelines, people's coping capacity and recovery potential are crucial to plan precautionary measures for adaptation and to mitigate potential impacts of tsunamis on society and the environment. A crucial point within a people-centred tsunami risk assessment is to quantify the human response capabilities towards tsunami threats. Based on this quantification and spatial representation in maps tsunami affected and safe areas, difficult-to-evacuate areas, evacuation target points and evacuation routes can be assigned and used as an important contribution to e.g. community level evacuation planning. Major component in the quantification of human response capabilities towards tsunami impacts is the factor time. The human response capabilities depend on the estimated time of arrival (ETA) of a tsunami, the time until technical or natural warning signs (ToNW) can be received, the reaction time (RT) of the population (human understanding of a tsunami warning and the decision to take appropriate action), the evacuation time (ET, time people need to reach a safe area) and the actual available response time (RsT = ETA - ToNW - RT). If RsT is larger than ET, people in the respective areas are able to reach a safe area and rescue themselves. Critical areas possess RsT values equal or even smaller ET and hence people whin these areas will be directly affected by a tsunami. Quantifying the factor time is challenging and an attempt to this is presented here. The ETA can be derived by analyzing pre-computed tsunami scenarios for a respective area. For ToNW we assume that the early warning center is able to fulfil the Indonesian presidential decree to issue a warning within 5 minutes. RT is difficult as here human intrinsic factors as educational level, believe, tsunami knowledge and experience besides others play a role. An attempt to quantify this variable under high uncertainty is also presented. Quantifying ET is based on a GIS modelling using a Cost Weighted Distance approach. Basic principle is to define the best evacuation path from a given point to the next safe area (shelter location). Here the fastest path from that point to the shelter location has to be found. Thereby the impact of land cover, slope, population density, population age and gender distribution are taken into account as literature studies prove these factors as highly important. Knowing the fastest path and the distance to the next safe area together with a spatially distributed pattern of evacuation speed delivers the time needed from each location to a safe area. By considering now the obtained time value for RsT the coverage area of an evacuation target point (safe area) can be assigned. Incorporating knowledge on people capacity of an evacuation target point the respective coverage area is refined. Hence areas with weak, moderate and good human response capabilities can be detected. This allows calculation of potential amount of people affected (dead or injured) and amount of people dislocated. First results for Kuta (Bali) for a worst case tsunami event deliver people affected of approx. 25 000 when RT = 0 minutes (direct evacuation when receiving a tsunami warning to 120 000 when RT > ETA (no evacuation action until tsunami hits the land). Additionally fastest evacuation routes to the evacuation target points can be assigned. Areas with weak response capabilities can be assigned as priority areas to install e.g. additional evacuation target points or to increase tsunami knowledge and awareness to promote a faster reaction time. Especially in analyzing underlying socio-economic properties causing deficiencies in responding to a tsunami threat can lead to valuable information and direct planning of adaptation measures. Keywords: Community level, Risk and vulnerability assessment, Early warning, Disaster management, Tsunami, Indonesia

Characterizing Mega-Earthquake Related Tsunami on Subduction Zones without Large Historical Events

NASA Astrophysics Data System (ADS)

Williams, C. R.; Lee, R.; Astill, S.; Farahani, R.; Wilson, P. S.; Mohammed, F.

2014-12-01

Due to recent large tsunami events (e.g., Chile 2010 and Japan 2011), the insurance industry is very aware of the importance of managing its exposure to tsunami risk. There are currently few tools available to help establish policies for managing and pricing tsunami risk globally. As a starting point and to help address this issue, Risk Management Solutions Inc. (RMS) is developing a global suite of tsunami inundation footprints. This dataset will include both representations of historical events as well as a series of M9 scenarios on subductions zones that have not historical generated mega earthquakes. The latter set is included to address concerns about the completeness of the historical record for mega earthquakes. This concern stems from the fact that the Tohoku Japan earthquake was considerably larger than had been observed in the historical record. Characterizing the source and rupture pattern for the subduction zones without historical events is a poorly constrained process. In many case, the subduction zones can be segmented based on changes in the characteristics of the subducting slab or major ridge systems. For this project, the unit sources from the NOAA propagation database are utilized to leverage the basin wide modeling included in this dataset. The length of the rupture is characterized based on subduction zone segmentation and the slip per unit source can be determined based on the event magnitude (i.e., M9) and moment balancing. As these events have not occurred historically, there is little to constrain the slip distribution. Sensitivity tests on the potential rupture pattern have been undertaken comparing uniform slip to higher shallow slip and tapered slip models. Subduction zones examined include the Makran Trench, the Lesser Antilles and the Hikurangi Trench. The ultimate goal is to create a series of tsunami footprints to help insurers understand their exposures at risk to tsunami inundation around the world.

Rescue, Archival and Discovery of Tsunami Events on Marigrams

NASA Astrophysics Data System (ADS)

Eble, M. C.; Wright, L. M.; Stroker, K. J.; Sweeney, A.; Lancaster, M.

2017-12-01

The Big Earth Data Initiative made possible the reformatting of paper marigram records on which were recorded measurements of the 1946, 1952, 1960, and 1964 tsunamis generated in the Pacific Ocean. Data contained within each record were determined to be invaluable for tsunami researchers and operational agencies with a responsibility for issuing warnings during a tsunami event. All marigrams were carefully digitized and metadata were generated to form numerical datasets in order to provide the tsunami and other research and application-driven communities with quality data. Data were then packaged as CF-compliant netCDF datafiles and submitted to the NOAA Centers for Environmental Information for long-term stewardship, archival, and public discovery of both original scanned images and data in digital netCDF and CSC formats. The PNG plots of each time series were generated and included with data packages to provide a visual representation of the numerical data sets. ISO-compliant metadata were compiled for the collection at the event level and individual DOIs were minted for each of the four events included in this project. The procedure followed to reformat each record in this four-event subset of the larger NCEI scanned marigram inventory is presented and discussed. The practical use of these data is presented to highlight that even infrequent measurements of tsunamis hold information that may potentially help constrain earthquake rupture area, provide estimates of earthquake co-seismic slip distribution, identify subsidence or uplift, and significantly increase the holdings of situ data available for tsunami model validation. These same data may also prove valuable to the broader global tide community for validation and further development of tide models and for investigation into the stability of tidal harmonic constants. Data reformatted as part of this project are PARR compliant and meet the requirements for Data Management, Discoverability, Accessibility, Documentation, Readability, and Data Preservation and Stewardship as per the Big Earth Data Initiative.

Tsunamis from Tectonic Sources along Caribbean Plate Boundaries

NASA Astrophysics Data System (ADS)

Lopez, A. M.; Chacon, S.; Zamora, N.; Audemard, F. A.; Dondin, F. J. Y.; Clouard, V.; Løvholt, F.; Harbitz, C. B.; Vanacore, E. A.; Huerfano Moreno, V. A.

2015-12-01

The Working Group 2 (WG2) of the Intergovernmental Coordination Group for the Tsunami and Other Coastal Hazards Warning System for the Caribbean and Adjacent Regions (ICG/CARIBE-EWS) in charge of Tsunami Hazards Assessment, has generated a list of tsunami sources for the Caribbean region. Simulating these worst-case, most credible scenarios would provide an estimate of the resulting effects on coastal areas within the Caribbean. In the past few years, several publications have addressed this issue resulting in a collection of potential tsunami sources and scenarios. These publications come from a wide variety of sources; from government agencies to academic institutions. Although these provide the scientific community with a list of sources and scenarios, it was the interest of the WG2 to evaluate what has been proposed and develop a comprehensive list of sources, therefore leaving aside proposed scenarios. The seismo-tectonics experts of the Caribbean within the WG2 members were tasked to evaluate comprehensively which published sources are credible, worst-cases, and consider other sources that have been omitted from available reports. Among these published sources are the GEM Faulted Earth Subduction Characterization Project, and the LANTEX/Caribe Wave annual exercise publications (2009-2015). Caribbean tectonic features capable of generating tsunamis from seismic dislocation are located along the Northeastern Caribbean, the Lesser Antilles Trench, and the Panamá and Southern Caribbean Deformed Belts. The proposed sources have been evaluated based on historical and instrumental seismicity as well as geological and geophysical studies. This paper presents the sources and their justification as most-probable tsunami sources based on the context of crustal deformation due to Caribbean plate interacting with neighboring North and South America plates. Simulations of these sources is part of a subsequent phase in which effects of these tectonically induced tsunamis are evaluated in the near-field, and wave history snapshots are used to estimate arrival times and coastal effects at other locations within the Caribbean basin. This study is part of a contribution of the WG2 of ICG/CARIBE-EWS to UNESCO's Intergovernmental Oceanographic Commission.

Research to Operations: From Point Positions, Earthquake and Tsunami Modeling to GNSS-augmented Tsunami Early Warning

NASA Astrophysics Data System (ADS)

Stough, T.; Green, D. S.

2017-12-01

This collaborative research to operations demonstration brings together the data and algorithms from NASA research, technology, and applications-funded projects to deliver relevant data streams, algorithms, predictive models, and visualization tools to the NOAA National Tsunami Warning Center (NTWC) and Pacific Tsunami Warning Center (PTWC). Using real-time GNSS data and models in an operational environment, we will test and evaluate an augmented capability for tsunami early warning. Each of three research groups collect data from a selected network of real-time GNSS stations, exchange data consisting of independently processed 1 Hz station displacements, and merge the output into a single, more accurate and reliable set. The resulting merged data stream is delivered from three redundant locations to the TWCs with a latency of 5-10 seconds. Data from a number of seismogeodetic stations with collocated GPS and accelerometer instruments are processed for displacements and seismic velocities and also delivered. Algorithms for locating and determining the magnitude of earthquakes as well as algorithms that compute the source function of a potential tsunami using this new data stream are included in the demonstration. The delivered data, algorithms, models and tools are hosted on NOAA-operated machines at both warning centers, and, once tested, the results will be evaluated for utility in improving the speed and accuracy of tsunami warnings. This collaboration has the potential to dramatically improve the speed and accuracy of the TWCs local tsunami information over the current seismometer-only based methods. In our first year of this work, we have established and deployed an architecture for data movement and algorithm installation at the TWC's. We are addressing data quality issues and porting algorithms into the TWCs operating environment. Our initial module deliveries will focus on estimating moment magnitude (Mw) from Peak Ground Displacement (PGD), within 2-3 minutes of the event, and coseismic displacements converging to static offsets. We will also develop visualizations of module outputs tailored to the operational environment. In the context of this work, we will also discuss this research to operations approach and other opportunities within the NASA Applied Science Disaster Program.

Evaluation of Refuge Life Risk using Geographical and Social Grid-Models with Satellite-Based House Ratio and Flood Depth by Tsunami Simulation

NASA Astrophysics Data System (ADS)

Kaneko, D.; Hosoyamada, T.

2017-12-01

The authors have developed social and geographical models for evaluating and applying life risk to the Kamakura coast near the south-western part of the metropolitan areas of Tokyo. The coastline close to the seismic center of the South Kanto earthquake is in the riskiest belt in the metropolitan area with a high possibility of house collapse and tsunami run-up. Kamakura is an important historical city, visited by many tourists who are not familiar with seismic dangers. There is a high probability of loss of human life during an evacuation of the city during tsunami waves. To evaluate the distribution of life risk characteristics in the area, models for citizens and sightseers are developed that includes social data such as population density, wooden-house ratio, and geographical evacuation distance and tsunami-flooding depth. The population of Kamakura City is 174,050 and the risk of tsunami evacuation is high in the area from the southern part of Kamakura Station to Zaimokuza block, where the population is approximately 15,310 people. There are about 26,000 tourists visiting this area on weekdays and about 100,000 sightseers visiting the area on Saturdays and Sundays. On weekdays the population per mesh will increase by half of the 2,000 inhabitants. On Saturdays and Sundays the population density will be 4 thousand who will double those of the inhabitants. A disaster prevention hill is proposed as a tsunami countermeasure on the coast of Kamakura City. The hill is covered by pine forest with a high-standard road, evacuation center, and sightseeing parking lots embedded in the hilly bank. In normal times, tourists and citizens use this area as a seaside pine park. Long concrete box structures strengthen the hill inside the mound, which has two levels, the lower equipped with high-standard-width roads on the ground level. The parking areas will resolve daily traffic congestion issues along the Kamakura main streets. The evaluation of over-flooding tsunamis and evacuation measures against life risk have been created using satellite land-cover classification data in the city. The two models using tsunami-flooding simulation have been used to design the disaster prevention hill. The results obtained contribute to preparing the society for disaster prevention measures or reconstruction after tsunami disasters.

Statistical Analysis of Tsunami Variability

NASA Astrophysics Data System (ADS)

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 similar to that seen in ground motion attenuation correlations used for seismic hazard assessment. The second issue was intra-event variability. This refers to the differences in tsunami wave run-up along a section of coast during a single event. Intra-event variability investigated directly considering field observations. The tsunami events used in the statistical evaluation were selected on the basis of the completeness and reliability of the available data. Tsunami considered for the analysis included the recent and well surveyed tsunami of Boxing Day 2004 (Great Indian Ocean Tsunami), Java 2006, Okushiri 1993, Kocaeli 1999, Messina 1908 and a case study of several historic events in Hawaii. Basic statistical analysis was performed on the field observations from these tsunamis. For events with very wide survey regions, the run-up heights have been grouped in order to maintain a homogeneous distance from the source. Where more than one survey was available for a given event, the original datasets were maintained separately to avoid combination of non-homogeneous data. The observed run-up measurements were used to evaluate the minimum, maximum, average, standard deviation and coefficient of variation for each data set. The minimum coefficient of variation was 0.12 measured for the 2004 Boxing Day tsunami at Nias Island (7 data) while the maximum is 0.98 for the Okushiri 1993 event (93 data). The average coefficient of variation is of the order of 0.45.

CAT: the INGV Tsunami Alert Center

NASA Astrophysics Data System (ADS)

Michelini, A.

2014-12-01

After the big 2004 Sumatra earthquake, the tsunami threat posed by large earthquakes occurring in the Mediterranean sea was formally taken into account by many countries around the Mediterranean basin. In the past, large earthquakes that originated significant tsunamis occurred nearly once per century (Maramai et al., 2014, Annals of Geophysics). The Intergovernmental Oceanographic Commission of UNESCO (IOC-UNESCO) received a mandate from the international community to coordinate the establishment of the ICG/NEAMTWS (http://neamtic.ioc-unesco.org) through Resolution IOC-XXIII-14. Since then, several countries (France, Turkey, Greece) have started operating as candidate Tsunami Watch Provider (cTWP) in the Mediterranean. Italy started operating as cTWP on October 1st, 2014. The Italian cTWP is formed by INGV ("Istituto Nazionale di Geofisica e Vulcanologia)", DPC ("Dipartimento di Protezione Civile") and ISPRA ("Istituto Superiore per la Protezione e la Ricerca Ambientale"). INGV is in charge of issuing the alert for potentially tsunamigenic earthquakes, ISPRA provides the sea level recordings and DPC is in charge of disseminating the alert. INGV established the tsunami alert center (CAT, "Centro di Allerta Tsunami") at the end of 2013. CAT is co-located with the INGV national seismic surveillance center operated since many years. In this work, we show the technical and personnel organization of CAT, its response to recent earthquakes, and the new procedures under development for implementation. (*) INGV-CAT WG: Amato A., Basili R., Bernardi F., Bono A., Danecek P., De Martini P.M., Govoni A., Graziani L., Lauciani V., Lomax, A., Lorito S., Maramai A., Mele F., Melini D., Molinari I., Nostro C., Piatanesi A., Pintore S., Quintiliani M., Romano F., Selva J., Selvaggi G., Sorrentino D., Tonini R.

Estimation of human damage and economic loss of buildings for the worst-credible scenario of tsunami inundation in the city of Augusta, Italy

NASA Astrophysics Data System (ADS)

Pagnoni, Gianluca; Tinti, Stefano

2017-04-01

The city of Augusta is located in the southern part of the eastern coast of Sicily. Italian tsunami catalogue and paleo-tsunami surveys indicate that at least 7 events of tsunami affected the bay of Augusta in the last 4,000 years, two of which are associated with earthquakes (1169 and 1693) that destroyed the city. For these reasons Augusta has been chosen in the project ASTARTE as a test site for the study of issues related to tsunami hazard and risk. In last two years we studied hazard through the approach of the worst-case credible scenario and carried out vulnerability and damage analysis for buildings. In this work, we integrate that research, and estimate the damage to people and the economic loss of buildings due to structural damage. As regards inundation, we assume both uniform inundation levels (bath-tub hypothesis) and inundation data resulting from the worst-case scenario elaborated for the area by Armigliato et al. (2015). Human damage is calculated in three steps using the method introduced by Pagnoni et al. (2016) following the work by Terrier et al. (2012) and by Koshimura et al. (2009). First, we use census data to estimate the number of people present in each residential building affected by inundation; second, based on water column depth and building type, we evaluate the level of damage to people; third, we provide an estimate of fatalities. The economic loss is computed for two types of buildings (residential and trade-industrial) by using data on inundation and data from the real estate market. This study was funded by the EU Project ASTARTE - "Assessment, STrategy And Risk Reduction for Tsunamis in Europe", Grant 603839, 7th FP (ENV.2013.6.4-3)

Place-classification analysis of community vulnerability to near-field tsunami threats in the U.S. Pacific Northwest (Invited)

NASA Astrophysics Data System (ADS)

Wood, N. J.; Jones, J.; Spielman, S.

2013-12-01

Near-field tsunami hazards are credible threats to many coastal communities throughout the world. Along the U.S. Pacific Northwest coast, low-lying areas could be inundated by a series of catastrophic tsunami waves that begin to arrive in a matter of minutes following a Cascadia subduction zone (CSZ) earthquake. This presentation summarizes analytical efforts to classify communities with similar characteristics of community vulnerability to tsunami hazards. This work builds on past State-focused inventories of community exposure to CSZ-related tsunami hazards in northern California, Oregon, and Washington. Attributes used in the classification, or cluster analysis, include demography of residents, spatial extent of the developed footprint based on mid-resolution land cover data, distribution of the local workforce, and the number and type of public venues, dependent-care facilities, and community-support businesses. Population distributions also are characterized by a function of travel time to safety, based on anisotropic, path-distance, geospatial modeling. We used an unsupervised-model-based clustering algorithm and a v-fold, cross-validation procedure (v=50) to identify the appropriate number of community types. We selected class solutions that provided the appropriate balance between parsimony and model fit. The goal of the vulnerability classification is to provide emergency managers with a general sense of the types of communities in tsunami hazard zones based on similar characteristics instead of only providing an exhaustive list of attributes for individual communities. This classification scheme can be then used to target and prioritize risk-reduction efforts that address common issues across multiple communities. The presentation will include a discussion of the utility of proposed place classifications to support regional preparedness and outreach efforts.

The Role of Near-Shore Bathymetry During Tsunami Inundation in a Reef Island Setting: A Case Study of Tutuila Island

NASA Astrophysics Data System (ADS)

Dilmen, Derya I.; Roe, Gerard H.; Wei, Yong; Titov, Vasily V.

2018-04-01

On September 29, 2009 at 17:48 UTC, an M w = 8.1 earthquake in the Tonga Trench generated a tsunami that caused heavy damage across Samoa, American Samoa, and Tonga. One of the worst hits was the volcanic island of Tutuila in American Samoa. Tutuila has a typical tropical island bathymetry setting influenced by coral reefs, and so the event provided an opportunity to evaluate the relationship between tsunami dynamics and the bathymetry in that typical island environment. Previous work has come to differing conclusions regarding how coral reefs affect tsunami dynamics through their influence on bathymetry and dissipation. This study presents numerical simulations of this event with a focus on two main issues: first, how roughness variations affect tsunami run-up and whether different values of Manning's roughness parameter, n, improve the simulated run-up compared to observations; and second, how depth variations in the shelf bathymetry with coral reefs control run-up and inundation on the island coastlines they shield. We find that no single value of n provides a uniformly good match to all observations; and we find substantial bay-to-bay variations in the impact of varying n. The results suggest that there are aspects of tsunami wave dissipation which are not captured by a simplified drag formulation used in shallow-water waves model. The study also suggests that the primary impact of removing the near-shore bathymetry in coral reef environment is to reduce run-up, from which we conclude that, at least in this setting, the impact of the near-shore bathymetry is to increase run-up and inundation.

The Great East-Japan Earthquake and devastating tsunami: an update and lessons from the past Great Earthquakes in Japan since 1923.

PubMed

Ishigaki, Akemi; Higashi, Hikari; Sakamoto, Takako; Shibahara, Shigeki

2013-04-01

Japan has a long history of fighting against great earthquakes that cause structural damage/collapses, fires and/or tsunami. On March 11, 2011 at 14:46 (Friday), the Great East-Japan Earthquake (magnitude 9.0) attacked the Tohoku region (northeastern Japan), which includes Sendai City. The earthquake generated a devastating tsunami, leading to unprecedented disasters (~18,500 victims) in coastal areas of Iwate, Miyagi and Fukushima prefectures, despite the fact that people living in the Tohoku region are well trained for tsunami-evacuation procedures, with the mindset of "Tsunami, ten-den-ko." This code means that each person should evacuate individually upon an earthquake. Sharing this rule, children and parents can escape separately from schools, houses or workplaces, without worrying about each other. The concept of ten-den-ko (individual evacuation) is helpful for people living in coastal areas of earthquake-prone zones around the world. It is also important to construct safe evacuation centers, because the March 11(th) tsunami killed people who had evacuated to evacuation sites. We summarize the current conditions of people living in the disaster-stricken areas, including the consequences of the Fukushima nuclear accident. We also describe the disaster responses as the publisher of the Tohoku Journal of Experimental Medicine (TJEM), located in Sendai, with online support from Tokyo. In 1923, the Great Kanto Earthquake (magnitude 7.9) evoked a massive fire that destroyed large areas of Tokyo (~105,000 victims), including the print company for TJEM, but the Wistar Institute printed three TJEM issues in 1923 in Philadelphia. Mutual aid relationships should be established between distant cities to survive future disasters.

The Role of Near-Shore Bathymetry During Tsunami Inundation in a Reef Island Setting: A Case Study of Tutuila Island

NASA Astrophysics Data System (ADS)

Dilmen, Derya I.; Roe, Gerard H.; Wei, Yong; Titov, Vasily V.

2018-02-01

On September 29, 2009 at 17:48 UTC, an M w = 8.1 earthquake in the Tonga Trench generated a tsunami that caused heavy damage across Samoa, American Samoa, and Tonga. One of the worst hits was the volcanic island of Tutuila in American Samoa. Tutuila has a typical tropical island bathymetry setting influenced by coral reefs, and so the event provided an opportunity to evaluate the relationship between tsunami dynamics and the bathymetry in that typical island environment. Previous work has come to differing conclusions regarding how coral reefs affect tsunami dynamics through their influence on bathymetry and dissipation. This study presents numerical simulations of this event with a focus on two main issues: first, how roughness variations affect tsunami run-up and whether different values of Manning's roughness parameter, n, improve the simulated run-up compared to observations; and second, how depth variations in the shelf bathymetry with coral reefs control run-up and inundation on the island coastlines they shield. We find that no single value of n provides a uniformly good match to all observations; and we find substantial bay-to-bay variations in the impact of varying n. The results suggest that there are aspects of tsunami wave dissipation which are not captured by a simplified drag formulation used in shallow-water waves model. The study also suggests that the primary impact of removing the near-shore bathymetry in coral reef environment is to reduce run-up, from which we conclude that, at least in this setting, the impact of the near-shore bathymetry is to increase run-up and inundation.

The September 16, 2015 Illapel Tsunami - Sedimentology of tsunami deposits at the beaches of La Serena and Coquimbo

NASA Astrophysics Data System (ADS)

Bahlburg, H.; Nentwig, V.; Kreutzer, M.

2016-12-01

On September 16, 2015, a Mw 8.3 earthquake occurred off the coast of Central Chile, 46 km west of the town of Illapel, the hypocenter was at a depth of 8.7 km in the transition zone from the Chilean flat slab to the central Chilean steep slab subduction geometry, and near the intersection of the Juan Fernandez Ridge with the South America plate. The quake caused a tsunami registered which at Coquimbo and La Serena (c. 30°S) attained wave heights of 4.5 m leading to flooding and destruction of infrastructure. Maximum inundation distance was c. 700 m in Coquimbo Bay with minor flooding at the beaches of La Serena to the N. Tsunami deposits are usually the only observable evidence of past events. In view of a limited preservation potential, it is of paramount importance to undertake detailed studies in the wake of actual events. We report initial field data of a sedimentological post-tsunami field survey undertaken in October 2015. The most comprehensive sedimentological record of this tsunami is preserved at Playa Los Fuertes in La Serena. Along a 30 m long trench perpendicular to the coast we observed a laminated package of tsunami deposits. Above an erosive basal unconformity with an amplitude of up to 50 cm the deposit consists of 6 layers of variable thickness, ranging between dark laminae a few millimeters thick and rich in heavy minerals, and lighter colored sand layers up to 15 cm thick. The sediments are moderately well to well sorted, unimodal with modes between 1.3 and 2.0 Φ (medium sand). Cross-beds in the lower four layers indicate deposition from tsunami inflow, cross bedding in the penultimate layer records outflow. Water escape through small sand volcanoes was coeval to formation of the overlying sediment layer by traction deposition. This simultaneity is indicated by sand issued from the lower layer which has been preserved as a thin plume deformed in the downcurrent, i.e. landward, direction in the newly forming upper layer. Other sectors of the sediment show sand diapirs intruding up to 15 cm into the overlying tsunami deposit. The assemblage of laminae, layers and sedimentary structures indicates that the deposit records at least 4 events of tsunami inflow and one outflow event. Intervening layers without directional structures cannot be assigned unequivocally to either inflow or outflow deposition.

Issues on the Japanese Earthquake Hazard Evaluation

NASA Astrophysics Data System (ADS)

Hashimoto, M.; Fukushima, Y.; Sagiya, T.

2013-12-01

The 2011 Great East Japan Earthquake forced the policy of counter-measurements to earthquake disasters, including earthquake hazard evaluations, to be changed in Japan. Before the March 11, Japanese earthquake hazard evaluation was based on the history of earthquakes that repeatedly occurs and the characteristic earthquake model. The source region of an earthquake was identified and its occurrence history was revealed. Then the conditional probability was estimated using the renewal model. However, the Japanese authorities changed the policy after the megathrust earthquake in 2011 such that the largest earthquake in a specific seismic zone should be assumed on the basis of available scientific knowledge. According to this policy, three important reports were issued during these two years. First, the Central Disaster Management Council issued a new estimate of damages by a hypothetical Mw9 earthquake along the Nankai trough during 2011 and 2012. The model predicts a 34 m high tsunami on the southern Shikoku coast and intensity 6 or higher on the JMA scale in most area of Southwest Japan as the maximum. Next, the Earthquake Research Council revised the long-term earthquake hazard evaluation of earthquakes along the Nankai trough in May 2013, which discarded the characteristic earthquake model and put much emphasis on the diversity of earthquakes. The so-called 'Tokai' earthquake was negated in this evaluation. Finally, another report by the CDMC concluded that, with the current knowledge, it is hard to predict the occurrence of large earthquakes along the Nankai trough using the present techniques, based on the diversity of earthquake phenomena. These reports created sensations throughout the country and local governments are struggling to prepare counter-measurements. These reports commented on large uncertainty in their evaluation near their ends, but are these messages transmitted properly to the public? Earthquake scientists, including authors, are involved in the discussion of these issues as committee members. However, we are wondering if the basis of these reports is scientifically appropriate. For example, there is no established method to evaluate the maximum size of earthquake, whose record is not known, in a specific area, but the committee made an estimate for the Nankai trough by extrapolating available knowledge. The Japanese policy makers further requested the probability of occurrence of such an event, which the committee had to decline because of the lack of knowledge. This example shows that Japanese earthquake scientists sometimes are involved in an important decision-making and are urged to go beyond the limit of earthquake science. We consider this difficult situation is formed on the basis of the history of the Japanese earthquake science and the 'myth of flawless of science' in the government and society, who often ask for a simple answer. Open discussion with people from other fields of science, such as social and human sciences, and the public would be an effective solution for the public to understand the complexity of the problems and to encourage appropriate counter-measures.

Automatic Hypocenter Determination Method in JMA Catalog and its Application

NASA Astrophysics Data System (ADS)

Tamaribuchi, K.

2017-12-01

The number of detectable earthquakes around Japan has increased by developing the high-sensitivity seismic observation network. After the 2011 Tohoku-oki earthquake, the number of detectable earthquakes have dramatically increased due to its aftershocks and induced earthquakes. This enormous number of earthquakes caused inability of manually determination of all the hypocenters. The Japan Meteorological Agency (JMA), which produces the earthquake catalog in Japan, has developed a new automatic hypocenter determination method and started its operation from April 1, 2016. This method (named PF method; Phase combination Forward search method) can determine the hypocenters of earthquakes that occur simultaneously by searching for the optimal combination of P- and S-wave arrival times and the maximum amplitudes using a Bayesian estimation technique. In the 2016 Kumamoto earthquake sequence, we successfully detected about 70,000 aftershocks automatically during the period from April 14 to the end of May, and this method contributed to the real-time monitoring of the seismic activity. Furthermore, this method can be also applied to the Earthquake Early Warning (EEW). Application of this method for EEW is called the IPF method and has been used as the hypocenter determination method of the EEW system in JMA from December 2016. By developing this method further, it is possible to contribute to not only speeding up the catalog production, but also improving reliability of the early warning.

Estimation of the effects of heavy Asian dust on respiratory function by definition type.

PubMed

Kurai, Jun; Watanabe, Masanari; Noma, Hisashi; Iwata, Kyoko; Taniguchi, Jumpei; Sano, Hiroyuki; Tohda, Yuji; Shimizu, Eiji

2017-01-01

The adverse effects of Asian dust (AD) on health have been demonstrated in earlier studies, but there is no standardized definition for heavy-AD. This study aimed to examine which definition of heavy-AD has the most adverse effect on respiratory function. One-hundred-and-thirty-seven adults with asthma, and 384 school children self-measured their morning peak expiratory flow (PEF). The four definitions of heavy-AD are: (1) the definition provided by the Japan Meteorological Agency (JMA), (2) daily median AD particle level ≥ 0.07 km -1 , obtained through light detection and ranging (LIDAR) (3) hourly AD particle level ≥ 0.1 km -1 , and (4) hourly level ≥ 0.07 km -1 . Linear mixed models were used to estimate the effects of heavy-AD, by definition type, on daily PEF values. In adults with asthma, as per the JMA's definition, significantly reduced PEF were observed on heavy-AD days (lag 0), lag 0-1, and lag 0-3. In school children, after a heavy-AD event, as defined by the JMA, PEF significantly decreased on lag 0-1, lag 0-2, and lag 0-3. However, as per the other definitions, there was no significant decrease in the PEF in the adults and children. The associations between heavy-AD and respiratory function differed between these definitions.

Estimating Seismic Moment From Broadband P-Waves for Tsunami Warnings.

NASA Astrophysics Data System (ADS)

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 8.1, Mwp 8.7 respectively, from p-waves recorded at 15 - 90 degrees from each hypocenter.

Trauma-related symptoms in Sri Lankan adult survivors after the tsunami: pretraumatic and peritraumatic factors.

PubMed

Gunaratne, Charini D; Kremer, Peter J; Clarke, Valerie; Lewis, Andrew J

2014-07-01

Limited research has addressed factors associated with psychological distress following disasters among non-Western populations. The 2004 tsunami affected 1.7 million people across South Asia and Africa, with considerable variations in trauma-related outcomes. Pretraumatic and peritraumatic conditions associated with trauma-related symptoms in 305 Sri Lankan adult survivors (28% male, aged 18-83 years; mean = 39.9 years; standard deviation = 15.3), clinically assessed 1 month posttsunami, were evaluated retrospectively. Outcome measures were total scores on 11 trauma-related symptoms. Multivariate linear regression analyses tested for associations between pretraumatic and peritraumatic conditions and symptom scores, with peritraumatic conditions adjusted for pretraumatic variables. Pretraumatic conditions of female gender, employment, prior health and social issues, and substance use and peritraumatic conditions of loss of family, witnessing the tsunami, or suffering an injury were associated with trauma-related symptoms. The findings facilitate understanding cultural contexts that define risk factors associated with trauma-related symptoms in Sri Lankans, which are critical for developing culturally appropriate interventions. © 2013 APJPH.

Vulnerability of port and harbor communities to earthquake and tsunami hazards: The use of GIS in community hazard planning

USGS Publications Warehouse

Wood, Nathan J.; Good, James W.

2004-01-01

AbstractEarthquakes and tsunamis pose significant threats to Pacific Northwest coastal port and harbor communities. Developing holistic mitigation and preparedness strategies to reduce the potential for loss of life and property damage requires community-wide vulnerability assessments that transcend traditional site-specific analyses. The ability of a geographic information system (GIS) to integrate natural, socioeconomic, and hazards information makes it an ideal assessment tool to support community hazard planning efforts. This article summarizes how GIS was used to assess the vulnerability of an Oregon port and harbor community to earthquake and tsunami hazards, as part of a larger risk-reduction planning initiative. The primary purposes of the GIS were to highlight community vulnerability issues and to identify areas that both are susceptible to hazards and contain valued port and harbor community resources. Results of the GIS analyses can help decision makers with limited mitigation resources set priorities for increasing community resiliency to natural hazards.

Tsunami modelling with adaptively refined finite volume methods

USGS Publications Warehouse

LeVeque, R.J.; George, D.L.; Berger, M.J.

2011-01-01

Numerical modelling of transoceanic tsunami propagation, together with the detailed modelling of inundation of small-scale coastal regions, poses a number of algorithmic challenges. The depth-averaged shallow water equations can be used to reduce this to a time-dependent problem in two space dimensions, but even so it is crucial to use adaptive mesh refinement in order to efficiently handle the vast differences in spatial scales. This must be done in a 'wellbalanced' manner that accurately captures very small perturbations to the steady state of the ocean at rest. Inundation can be modelled by allowing cells to dynamically change from dry to wet, but this must also be done carefully near refinement boundaries. We discuss these issues in the context of Riemann-solver-based finite volume methods for tsunami modelling. Several examples are presented using the GeoClaw software, and sample codes are available to accompany the paper. The techniques discussed also apply to a variety of other geophysical flows. ?? 2011 Cambridge University Press.

Indian Ocean tsunami: relationships among posttraumatic stress, posttraumatic growth, resource loss, and coping at 3 and 15 months.

PubMed

Sattler, David N; Assanangkornchai, Sawitri; Moller, Adam M; Kesavatana-Dohrs, Wiworn; Graham, James M

2014-01-01

This study examines variables associated with posttraumatic stress symptoms (PTS) and posttraumatic growth among 2 independent samples of survivors following the Indian Ocean tsunami in Khao Lak, Thailand. Participants were exposed to unprecedented horror and loss of life and property. At 3 months participants (N = 248) were living in temporary shelters, and at 15 months a second sample (N = 255) was living in homes built after the tsunami. Prior traumatic experiences, life threat, loss of personal characteristic resources and condition resources, somatic problems, and social support accounted for close to half of the variance in PTS in each sample. At 3 months, emotion-focused coping and concerns about government favoritism also contributed to PTS. At 15 months, lack of prior disaster experience and loss of energy resources also contributed to PTS. Distress was higher among participants surveyed at 3 months than among those surveyed at 15 months. Posttraumatic growth was positively associated with social support and problem-focused coping in both samples. The findings support conservation of resources stress theory ( Hobfoll, 2012 ) and underscore how systemic issues affect mental health. The implications of the findings are discussed, as is the educational International Tsunami Museum designed by the first author to address systemic stressors.

Complementary methods to plan pedestrian evacuation of the French Riviera's beaches in case of tsunami threat: graph- and multi-agent-based modelling

NASA Astrophysics Data System (ADS)

Sahal, A.; Leone, F.; Péroche, M.

2013-07-01

Small amplitude tsunamis have impacted the French Mediterranean shore (French Riviera) in the past centuries. Some caused casualties; others only generated economic losses. While the North Atlantic and Mediterranean tsunami warning system is being tested and is almost operational, no awareness and preparedness measure is being implemented at a local scale. Evacuation is to be considered along the French Riviera, but no plan exists within communities. We show that various approaches can provide local stakeholders with evacuation capacities assessments to develop adapted evacuation plans through the case study of the Cannes-Antibes region. The complementarity between large- and small-scale approaches is demonstrated with the use of macro-simulators (graph-based) and micro-simulators (multi-agent-based) to select shelter points and choose evacuation routes for pedestrians located on the beach. The first one allows automatically selecting shelter points and measuring and mapping their accessibility. The second one shows potential congestion issues during pedestrian evacuations, and provides leads for the improvement of urban environment. Temporal accessibility to shelters is compared to potential local and distal tsunami travel times, showing a 40 min deficit for an adequate crisis management in the first scenario, and a 30 min surplus for the second one.

Community clusters of tsunami vulnerability in the US Pacific Northwest

USGS Publications Warehouse

Wood, Nathan J.; Jones, Jeanne M.; Spielman, Seth; Schmidtlein, Mathew C.

2015-01-01

Many coastal communities throughout the world are threatened by local (or near-field) tsunamis that could inundate low-lying areas in a matter of minutes after generation. Although the hazard and sustainability literature often frames vulnerability conceptually as a multidimensional issue involving exposure, sensitivity, and resilience to a hazard, assessments often focus on one element or do not recognize the hazard context. We introduce an analytical framework for describing variations in population vulnerability to tsunami hazards that integrates (i) geospatial approaches to identify the number and characteristics of people in hazard zones, (ii) anisotropic path distance models to estimate evacuation travel times to safety, and (iii) cluster analysis to classify communities with similar vulnerability. We demonstrate this approach by classifying 49 incorporated cities, 7 tribal reservations, and 17 counties from northern California to northern Washington that are directly threatened by tsunami waves associated with a Cascadia subduction zone earthquake. Results suggest three primary community groups: (i) relatively low numbers of exposed populations with varied demographic sensitivities, (ii) high numbers of exposed populations but sufficient time to evacuate before wave arrival, and (iii) moderate numbers of exposed populations but insufficient time to evacuate. Results can be used to enhance general hazard-awareness efforts with targeted interventions, such as education and outreach tailored to local demographics, evacuation training, and/or vertical evacuation refuges.

Community clusters of tsunami vulnerability in the US Pacific Northwest.

PubMed

Wood, Nathan J; Jones, Jeanne; Spielman, Seth; Schmidtlein, Mathew C

2015-04-28

Many coastal communities throughout the world are threatened by local (or near-field) tsunamis that could inundate low-lying areas in a matter of minutes after generation. Although the hazard and sustainability literature often frames vulnerability conceptually as a multidimensional issue involving exposure, sensitivity, and resilience to a hazard, assessments often focus on one element or do not recognize the hazard context. We introduce an analytical framework for describing variations in population vulnerability to tsunami hazards that integrates (i) geospatial approaches to identify the number and characteristics of people in hazard zones, (ii) anisotropic path distance models to estimate evacuation travel times to safety, and (iii) cluster analysis to classify communities with similar vulnerability. We demonstrate this approach by classifying 49 incorporated cities, 7 tribal reservations, and 17 counties from northern California to northern Washington that are directly threatened by tsunami waves associated with a Cascadia subduction zone earthquake. Results suggest three primary community groups: (i) relatively low numbers of exposed populations with varied demographic sensitivities, (ii) high numbers of exposed populations but sufficient time to evacuate before wave arrival, and (iii) moderate numbers of exposed populations but insufficient time to evacuate. Results can be used to enhance general hazard-awareness efforts with targeted interventions, such as education and outreach tailored to local demographics, evacuation training, and/or vertical evacuation refuges.

The role of deposits in tsunami risk assessment

USGS Publications Warehouse

Jaffe, B.

2008-01-01

An incomplete catalogue of tsunamis in the written record hinders tsunami risk assessment. Tsunami deposits, hard evidence of tsunami, can be used to extend the written record. The two primary factors in tsunami risk, tsunami frequency and magnitude, can be addressed through field and modeling studies of tsunami deposits. Recent research has increased the utility of tsunami deposits in tsunami risk assessment by improving the ability to identify tsunami deposits and developing models to determine tsunami magnitude from deposit characteristics. Copyright ASCE 2008.

Forecast simulation of rapidly-intensified typhoon in the Eddy-Rich Northwest Pacific region

NASA Astrophysics Data System (ADS)

Kim, Kyeong Ok; Yuk, Jin-Hee; Jung, Kyung Tae; Kuh Kang, Suk

2017-04-01

The real-time typhoon predictions in the Northwest Pacific (NWP) are being distributed by various agencies (for example, KMA, JMA, JTWC, NMC, CWB, HKO and PAGASA). Currently the movement of the typhoon can be predicted with an error of less than 100 km in 48 hours, however it is difficult to the predict of the intensity of the typhoon especially the Rapidly Intensified (RI) Typhoons. The mean occurrence of RI typhoon amounts to 5.4 times a year during 39 years (1977-2015), occupying 21% of typhoons in NWP. Especially the RI typhoon in the Eddy-Rich Northwest Pacific (ER-NWP) occurred 1.8 times a year, covering 29% of typhoons in ER-NWP. A RI typhoon, NEPARTAK (T201601), occurred in July 2016. It was formed in Caroline Islands and moved northwest, straightly heading for Taiwan. However, at the beginning stage many forecasting agencies predicts as move to the Yellow Sea. The accuracy of prediction data of the Typhoon NEPARTAK (T201601) from KMA, JMA and JTWC was compared with the adjusted best-track data from Digital-Typhoon (JMA-RSMC). The sequential prediction data are summarized with 6-hour interval from 3th to 10th July 2016.The JMA prediction of the typhoon track and the JTWC predictions of the maximum wind speed were found to be best. The numerical simulations using WRF model forced with NCEP GFS prediction data and microwave SST is compared. The simulations using one domain (D1), two domains (D2) using a moving nest scheme, and with or without the spectral nudging (-SN) are compared. Comparison of the errors on the track shows the differences of 100 km in 48-hour prediction and200 km in 72-hour prediction on average. The best results on the track prediction are shown in the D2 case of WRF model. However, underestimation of the maximum wind speed of WRF prediction still exists, obviously requiring better understanding of RI-related processes to improve the model prediction.

Disaster dentistry.

PubMed

Hinchliffe, J A

2007-04-28

This article gives a brief glimpse of some of the issues involved with dental identification of fatalities in disaster situations. It is based on the personal views and experiences of the author as a forensic dentist in the aftermath of the Asian tsunami and the Sharm el Sheikh bombings.

Defining Tsunami Magnitude as Measure of Potential Impact

NASA Astrophysics Data System (ADS)

Titov, V. V.; Tang, L.

2016-12-01

The goal of tsunami forecast, as a system for predicting potential impact of a tsunami at coastlines, requires quick estimate of a tsunami magnitude. This goal has been recognized since the beginning of tsunami research. The work of Kajiura, Soloviev, Abe, Murty, and many others discussed several scales for tsunami magnitude based on estimates of tsunami energy. However, difficulties of estimating tsunami energy based on available tsunami measurements at coastal sea-level stations has carried significant uncertainties and has been virtually impossible in real time, before tsunami impacts coastlines. The slow process of tsunami magnitude estimates, including collection of vast amount of available coastal sea-level data from affected coastlines, made it impractical to use any tsunami magnitude scales in tsunami warning operations. Uncertainties of estimates made tsunami magnitudes difficult to use as universal scale for tsunami analysis. Historically, the earthquake magnitude has been used as a proxy of tsunami impact estimates, since real-time seismic data is available of real-time processing and ample amount of seismic data is available for an elaborate post event analysis. This measure of tsunami impact carries significant uncertainties in quantitative tsunami impact estimates, since the relation between the earthquake and generated tsunami energy varies from case to case. In this work, we argue that current tsunami measurement capabilities and real-time modeling tools allow for establishing robust tsunami magnitude that will be useful for tsunami warning as a quick estimate for tsunami impact and for post-event analysis as a universal scale for tsunamis inter-comparison. We present a method for estimating the tsunami magnitude based on tsunami energy and present application of the magnitude analysis for several historical events for inter-comparison with existing methods.

Tsunami early warning in the central Mediterranean: effect of the heterogeneity of the seismic source on the timely detectability of a tsunami

NASA Astrophysics Data System (ADS)

Armigliato, A.; Tinti, S.; Pagnoni, G.; Zaniboni, F.

2012-04-01

The central Mediterranean, and in particular the coasts of southern Italy, is one of the areas with the highest tsunami hazard in Europe. Limiting our attention to earthquake-generated tsunamis, the sources of historical events hitting this region, as well as the largest part of the potential tsunamigenic seismic sources mapped there, are found at very short distances from the closest shorelines, reducing the time needed for the tsunami to attack the coasts themselves to few minutes. This represents by itself an issue from the Tsunami Early Warning (TEW) perspective. To make the overall problem even more intriguing and challenging, it is known that large tsunamigenic earthquakes are generally characterized by highly heterogeneous distributions of the slip on the fault. This feature has been recognized clearly, for instance, in the giant Sumatra 2004, Chile 2010, and Japan 2011 earthquakes (magnitude 9.3, 8.8 and 9.0, respectively), but it was a property also of smaller magnitude events occurred in the region considered in this study, like the 28 December 1908 Messina Straits tsunamigenic earthquake (M=7.2). In terms of tsunami impact, the parent fault slip heterogeneity usually determines a high variability of run-up and inundation on the near-field coasts, which further complicates the TEW problem. The information on the details of the seismic source rupture coming from the seismic (and possibly geodetic) networks, though of primary importance, is typically available after a time that is comparable or larger than the time comprised between the generation and the impact of the tsunami. In the framework of the EU-FP7 TRIDEC Project, we investigate how a proper marine sensors coverage both along the coasts and offshore can help posing constraints on the characteristics of the source in near-real time. Our approach consists in discussing numerical tsunami scenarios in the central Mediterranean involving different slip distributions on the parent fault; the tsunamigenic region we take into consideration is the Hyblaean-Malta escarpment located offshore eastern Sicily, where several large historical tsunamigenic earthquakes took place (e.g. 11 January 1693). Starting from different slip configurations on a chosen fault, we compare the time series of wave elevation simulated for tide gauges placed along the coast and for virtual deep sea sensors placed at different distances from the source area. The final goal is to understand whether a properly designed marine sensor network can help determining in real-time the slip characteristics along the parent fault and hence forecasting the pattern of impact of the tsunami especially along the closest coasts.

Compilation and Analysis of a Database of Local Tsunami Bulletins issued by the Pacific Tsunami Warning Center (PTWC) to the Hawaii Emergency Management Agency (HI-EMA) between September 2003 and July, 2015

NASA Astrophysics Data System (ADS)

Sardina, V.; Koyanagi, K. K.; Walsh, D.; Becker, N. C.; McCreery, C.

2015-12-01

The PTWC functions not only as official international tsunami warning center (TWC) for nations with coasts around the Pacific rim, the Caribbean, and other regions of the world, but also as the local TWC for the State of Hawaii. The PTWC began sending local tsunami messages to HI-EMA only since September, 2003. As part of its routine operations, the PTWC strives to send a local tsunami message product for any Hawaii earthquake with a 4.0 magnitude or larger within five minutes of origin time. To evaluate PTWC's performance in that regard, however, we must first compile a suitable local tsunami bulletins' database. For this purpose, we scanned all the available logs for the Federal Aviation Administration (FAA) communications' circuit between 2003 and 2015 and retrieved 104 local bulletins. We parsed these bulletins and extracted the parametric data needed to evaluate PTWC's performance in terms of essential statistics such as message delay time, epicenter offsets, and magnitude residuals as compared with more authoritative earthquake source parametrizations. To that end, we cross-validated 88 of these seismic events having magnitudes between 2.8 and 6.7 with the corresponding source parameters obtained from the USGS Hawaiian Volcano Observatory (HVO) and the National Earthquake Information Center's (NEIC) online catalog. Analysis of events with magnitude 4.0 or larger gives a median message delay time of 3 minutes and 33 seconds, a median epicentral offset of 3.2 km, and a median magnitude residual of 0.2 unit. Several message delay outliers exist due to the fact that PTWC has sent local tsunami information statements (TIS) for felt events with magnitudes as small as 2.8 located west of the Big Island. Routine use of a synthetic Wood-Anderson magnitude since the end of 2012 appears to have brought consistency to PTWC's local magnitude estimates and a reduction in the message delays. Station site corrections, a refined attenuation model, and optimization of the peak-amplitude search window may improve magnitude estimates. Improved dissemination software, regional moment tensor determinations for rapid magnitude estimation in addition to ML and Mwp can result in yet faster and more accurate tsunami message products.

Contribution of Anisotropy of Magnetic Susceptibility (AMS) to reconstruct flooding characteristics of a 4220 BP tsunami from a thick unconsolidated structureless deposit (Banda Aceh, Sumatra)

NASA Astrophysics Data System (ADS)

Wassmer, Patrick; Gomez, Christopher; Iskandasyah, T. Yan W. M.; Lavigne, Franck; Sartohadi, Junun

2015-07-01

One of the main concerns of deciphering tsunami sedimentary records along seashore is to link the emplaced layers with marine high energy events. Based on a combination of morphologic features, sedimentary figures, grain size characteristics, fossils content, microfossils assemblages, geochemical elements, heavy minerals presence; it is, in principle, possible to relate the sedimentary record to a tsunami event. However, experience shows that sometimes, in reason of a lack of any visible sedimentary features, it is hard to decide between a storm and a tsunami origin. To solve this issue, the authors have used the Anisotropy of Magnetic Susceptibility (AMS) to evidence the sediment fabric. The validity of the method for reconstructing flow direction has been proved when applied on sediments in the aftermath of a tsunami event, for which the behaviour was well documented (2004 IOT). We present herein an application of this method for a 56 cm thick paleo-deposit dated 4220 BP laying under the soil covered by the 2004 IOT, SE of Banda Aceh, North Sumatra. We analysed this homogenous deposit, lacking of any visible structure, using methods of classic sedimentology to confirm the occurrence of a high energy event. We then applied AMS technique that allowed the reconstruction of flow characteristics during sediment emplacement. We show that all the sequence was emplaced by uprush phases and that the local topography played a role on the re-orientation of a part of the uprush flow, creating strong reverse current. This particular behaviour was reported by eyewitnesses during the 2004 IOT event.

Physical modeling of long-wave run-up mitigation using submerged breakwaters

NASA Astrophysics Data System (ADS)

Lee, Yu-Ting; Wu, Yun-Ta; Hwung, Hwung-Hweng; Yang, Ray-Yeng

2016-04-01

Natural hazard due to tsunami inundation inland has been viewed as a crucial issue for coastal engineering community. The 2004 India Ocean tsunami and the 2011 Tohoku earthquake tsunami were caused by mega scale earthquakes that brought tremendous catastrophe in the disaster regions. It is thus of great importance to develop innovative approach to achieve the reduction and mitigation of tsunami hazards. In this study, new experiments have been carried out in a laboratory-scale to investigate the physical process of long-wave through submerged breakwaters built upon a mild slope. Solitary-wave is employed to represent the characteristic of long-wave with infinite wavelength and wave period. Our goal is twofold. First of all, through changing the positions of single breakwater and multiple breakwaters upon a mild slope, the optimal locations of breakwaters can be pointed out by means of maximum run-up reduction. Secondly, through using a state-of-the-art measuring technique Bubble Image Velocimetry, which features non-intrusive and image-based measurement, the wave kinematics in the highly aerated region due to solitary-wave shoaling, breaking and uprush can be quantitated. Therefore, the mitigation of long-wave due to the construction of submerged breakwaters built upon a mild slope can be evaluated not only for imaging run-up and run-down characteristics but also for measuring turbulent velocity fields due to breaking wave. Although we understand the most devastating tsunami hazards cannot be fully mitigated with impossibility, this study is to provide quantitated information on what kind of artificial coastal structure that can withstand which level of wave loads.

Tsunami Warning Center in Turkey : Status Update 2012

NASA Astrophysics Data System (ADS)

Meral Ozel, N.; Necmioglu, O.; Yalciner, A. C.; Kalafat, D.; Yilmazer, M.; Comoglu, M.; Sanli, U.; Gurbuz, C.; Erdik, M.

2012-04-01

This is an update to EGU2011-3094 informing on the progress of the establishment of a National Tsunami Warning Center in Turkey (NTWC-TR) under the UNESCO Intergovernmental Oceanographic Commission - Intergovernmental Coordination Group for the Tsunami Early Warning and Mitigation System in the North-eastern Atlantic, the Mediterranean and connected seas (IOC-ICG/NEAMTWS) initiative. NTWC-TR is integrated into the 24/7 operational National Earthquake Monitoring Center (NEMC) of KOERI comprising 129 BB and 61 strong motion sensors. Based on an agreement with the Disaster and Emergency Management Presidency (DEMP), data from 10 BB stations located in the Aegean and Mediterranean Coast is now transmitted in real time to KOERI. Real-time data transmission from 6 primary and 10 auxiliary stations from the International Monitoring System will be in place in the very near future based on an agreement concluded with the Comprehensive Nuclear Test Ban Treaty Organization (CTBTO) in 2011. In an agreement with a major Turkish GSM company, KOERI is enlarging its strong-motion network to promote real-time seismology and to extend Earthquake Early Warning system countrywide. 25 accelerometers (included in the number given above) have been purchased and installed at Base Transceiver Station Sites in coastal regions within the scope of this initiative. Data from 3 tide gauge stations operated by General Command of Mapping (GCM) is being transmitted to KOERI via satellite connection and the aim is to integrate all tide-gauge stations operated by GCM into NTWC-TR. A collaborative agreement has been signed with the European Commission - Joint Research Centre (EC-JRC) and MOD1 Tsunami Scenario Database and TAT (Tsunami Analysis Tool) are received by KOERI and user training was provided. The database and the tool are linked to SeisComp3 and currently operational. In addition KOERI is continuing the work towards providing contributions to JRC in order to develop an improved database (MOD2), and also continuing work related to the development of its own scenario database using NAMI DANCE Tsunami Simulation and Visualization Software. Further improvement of the Tsunami Warning System at the NTWC-TR will be accomplished through KOERI's participation in the FP-7 Project TRIDEC focusing on new technologies for real-time intelligent earth information management to be used in Tsunami Early Warning Systems. In cooperation with Turkish State Meteorological Service (TSMS), KOERI has its own GTS system now and connected to GTS via its own satellite hub. The system has been successfully utilized during the First Enlarged Communication Test Exercise (NEAMTWS/ECTE1), where KOERI acted as the message provider. KOERI is providing guidance and assistance to a working group established within the DEMP on issues such as Communication and Tsunami Exercises, National Procedures and National Tsunami Response Plan. KOERI is also participating in NEAMTIC (North-Eastern Atlantic and Mediterranean Tsunami Information Centre) Project. Finally, during the 8th Session of NEAMTWS in November 2011, KOERI has announced that NTWC-TR is operational as of January 2012 covering Eastern Mediterranean, Aegean, Marmara and Black Seas and KOERI is also ready to operate as an Interim Candidate Tsunami Watch Provider.

Fast Simulation of Tsunamis in Real Time

NASA Astrophysics Data System (ADS)

Fryer, G. J.; Wang, D.; Becker, N. C.; Weinstein, S. A.; Walsh, D.

2011-12-01

The U.S. Tsunami Warning Centers primarily base their wave height forecasts on precomputed tsunami scenarios, such as the SIFT model (Standby Inundation Forecasting of Tsunamis) developed by NOAA's Center for Tsunami Research. In SIFT, tsunami simulations for about 1600 individual earthquake sources, each 100x50 km, define shallow subduction worldwide. These simulations are stored in a database and combined linearly to make up the tsunami from any great earthquake. Precomputation is necessary because the nonlinear shallow-water wave equations are too time consuming to compute during an event. While such scenario-based models are valuable, they tacitly assume all energy in a tsunami comes from thrust at the décollement. The thrust assumption is often violated (e.g., 1933 Sanriku, 2007 Kurils, 2009 Samoa), while a significant number of tsunamigenic earthquakes are completely unrelated to subduction (e.g., 1812 Santa Barbara, 1939 Accra, 1975 Kalapana). Finally, parts of some subduction zones are so poorly defined that precomputations may be of little value (e.g., 1762 Arakan, 1755 Lisbon). For all such sources, a fast means of estimating tsunami size is essential. At the Pacific Tsunami Warning Center, we have been using our model RIFT (Real-time Inundation Forecasting of Tsunamis) experimentally for two years. RIFT is fast by design: it solves only the linearized form of the equations. At 4 arc-minutes resolution calculations for the entire Pacific take just a few minutes on an 8-processor Linux box. Part of the rationale for developing RIFT was earthquakes of M 7.8 or smaller, which approach the lower limit of the more complex SIFT's abilities. For such events we currently issue a fixed warning to areas within 1,000 km of the source, which typically means a lot of over-warning. With sources defined by W-phase CMTs, exhaustive comparison with runup data shows that we can reduce the warning area significantly. Even before CMTs are available, we routinely run models based on the local tectonics, which provide a useful first estimate of the tsunami. Our runup comparisons show that Green's Law (i.e., 1-D runup estimates) works very well indeed, especially if computations are run at 2 arc-minutes. We are developing an experimental RIFT-based product showing expected runups on open coasts. While these will necessarily be rather crude they will be a great help to emergency managers trying to assess the hazard. RIFT is typically run using a single source, but it can already handle multiple sources. In particular, it can handle multiple sources of different orientations such as 1993 Okushiri, or the décollement-splay combinations to be expected during major earthquakes in accretionary margins such as Nankai, Cascadia, and Middle America. As computers get faster and the number-crunching burden is off-loaded to GPUs, we are convinced there will still be a use for a fast, linearized, modeling capability. Rather than applying scaling laws to a CMT, or distributing slip over 100x50 km sub-faults, for example, it would be preferable to model tsunamis using the output from a finite-fault analysis. To accomplish such a compute-bound task fast enough for warning purposes will demand a rapid, approximate technique like RIFT.

Characteristics of the 2011 Tohoku Tsunami and introduction of two level tsunamis for tsunami disaster mitigation

PubMed Central

SATO, Shinji

2015-01-01

Characteristics of the 2011 Tohoku Tsunami have been revealed by collaborative tsunami surveys extensively performed under the coordination of the Joint Tsunami Survey Group. The complex behaviors of the mega-tsunami were characterized by the unprecedented scale and the low occurrence frequency. The limitation and the performance of tsunami countermeasures were described on the basis of tsunami surveys, laboratory experiments and numerical analyses. These findings contributed to the introduction of two-level tsunami hazards to establish a new strategy for tsunami disaster mitigation, combining structure-based flood protection designed by the Level-1 tsunami and non-structure-based damage reduction planned by the Level-2 tsunami. PMID:26062739

Characteristics of the 2011 Tohoku Tsunami and introduction of two level tsunamis for tsunami disaster mitigation.

PubMed

Sato, Shinji

2015-01-01

Characteristics of the 2011 Tohoku Tsunami have been revealed by collaborative tsunami surveys extensively performed under the coordination of the Joint Tsunami Survey Group. The complex behaviors of the mega-tsunami were characterized by the unprecedented scale and the low occurrence frequency. The limitation and the performance of tsunami countermeasures were described on the basis of tsunami surveys, laboratory experiments and numerical analyses. These findings contributed to the introduction of two-level tsunami hazards to establish a new strategy for tsunami disaster mitigation, combining structure-based flood protection designed by the Level-1 tsunami and non-structure-based damage reduction planned by the Level-2 tsunami.

Hydrometeorology as an Inversion Problem: Can River Discharge Observations Improve the Atmosphere by Ensemble Data Assimilation?

NASA Astrophysics Data System (ADS)

Sawada, Yohei; Nakaegawa, Tosiyuki; Miyoshi, Takemasa

2018-01-01

We examine the potential of assimilating river discharge observations into the atmosphere by strongly coupled river-atmosphere ensemble data assimilation. The Japan Meteorological Agency's Non-Hydrostatic atmospheric Model (JMA-NHM) is first coupled with a simple rainfall-runoff model. Next, the local ensemble transform Kalman filter is used for this coupled model to assimilate the observations of the rainfall-runoff model variables into the JMA-NHM model variables. This system makes it possible to do hydrometeorology backward, i.e., to inversely estimate atmospheric conditions from the information of river flows or a flood on land surfaces. We perform a proof-of-concept Observing System Simulation Experiment, which reveals that the assimilation of river discharge observations into the atmospheric model variables can improve the skill of the short-term severe rainfall forecast.

Tsunami on Sanriku Coast in 1586: Orphan or Ghost Tsunami ?

NASA Astrophysics Data System (ADS)

Satake, K.

2017-12-01

The Peruvian earthquake on July 9, 1586 was the oldest earthquake that damaged Lima. The tsunami height was assigned as 24 m in Callao and 1-2 m in Miyagi prefecture in Japan by Soloviev and Go (1975). Dorbath et al. (1990) studied historical earthquakes in Peru and estimated that the 1586 earthquake was similar to the 1974 event (Mw 8.1) with source length of 175 km. They referred two different tsunami heights, 3. 7m and 24 m, in Callao, and judged that the latter was exaggerated. Okal et al. (2006) could not make a source model to explain both tsunami heights in Callao and Japan. More recently, Butler et al. (2017) estimated the age of coral boulders in Hawaii as AD 1572 +/- 21, speculated the tsunami source in Aleutians, and attributed it to the source of the 1586 tsunami in Japan. Historical tsunamis, both near-field and far-field, have been documented along the Sanriku coast since 1586 (e.g., Watanabe, 1998). However, there is no written document for the 1586 tsunami (Tsuji et al., 2013). Ninomiya (1960) compiled the historical tsunami records on the Sanriku coast soon after the 1960 Chilean tsunami, and correlated the legend of tsunami in Tokura with the 1586 Peruvian earthquake, although he noted that the dates were different. About the legend, he referred to Kunitomi(1933) who compiled historical tsunami data after the 1933 Showa Sanriku tsunami. Kunitomi referred to "Tsunami history of Miyagi prefecture" published after the 1896 Meiji Sanriku tsunami. "Tsunami history" described the earthquake and tsunami damage of Tensho earthquake on January 18 (Gregorian),1586 in central Japan, and correlated the tsunami legend in Tokura on June 30, 1586 (G). Following the 2011 Tohoku tsunami, tsunami legend in Tokura was studied again (Ebina, 2015). A local person published a story he heard from his grandfather that many small valleys were named following the 1611 tsunami, which inundated further inland than the 2011 tsunami. Ebina (2015), based on historical documents, estimated that the legend existed around 1750. From the above research, the tsunami legend in Tokura is unlikely from the Peruvian earthquake. Hence the 1586 tsunami was not an orphan tsunami, but rather a ghost or fake tsunami. The legend simply mentioned about tsunami, but the tsunami heights were speculated as 1-2 m (Soloviev and Go) or 2 - 2.5 m (NOAA tsunami DB).

Tsunami geology in paleoseismology

USGS Publications Warehouse

Yuichi Nishimura,; Jaffe, Bruce E.

2015-01-01

The 2004 Indian Ocean and 2011 Tohoku-oki disasters dramatically demonstrated the destructiveness and deadliness of tsunamis. For the assessment of future risk posed by tsunamis it is necessary to understand past tsunami events. Recent work on tsunami deposits has provided new information on paleotsunami events, including their recurrence interval and the size of the tsunamis (e.g. [187–189]). Tsunamis are observed not only on the margin of oceans but also in lakes. The majority of tsunamis are generated by earthquakes, but other events that displace water such as landslides and volcanic eruptions can also generate tsunamis. These non-earthquake tsunamis occur less frequently than earthquake tsunamis; it is, therefore, very important to find and study geologic evidence for past eruption and submarine landslide triggered tsunami events, as their rare occurrence may lead to risks being underestimated. Geologic investigations of tsunamis have historically relied on earthquake geology. Geophysicists estimate the parameters of vertical coseismic displacement that tsunami modelers use as a tsunami's initial condition. The modelers then let the simulated tsunami run ashore. This approach suffers from the relationship between the earthquake and seafloor displacement, the pertinent parameter in tsunami generation, being equivocal. In recent years, geologic investigations of tsunamis have added sedimentology and micropaleontology, which focus on identifying and interpreting depositional and erosional features of tsunamis. For example, coastal sediment may contain deposits that provide important information on past tsunami events [190, 191]. In some cases, a tsunami is recorded by a single sand layer. Elsewhere, tsunami deposits can consist of complex layers of mud, sand, and boulders, containing abundant stratigraphic evidence for sediment reworking and redeposition. These onshore sediments are geologic evidence for tsunamis and are called ‘tsunami deposits’ (Figs. 26 and 27). Tsunami deposits can be classified into two groups: modern tsunami deposits and paleotsunami deposits. A modern tsunami deposit is a deposit whose source event is known. A paleotsunami deposit is a deposit whose age is estimated and has a source that is either inferred to be a historical event or is unknown.

Develop Probabilistic Tsunami Design Maps for ASCE 7

NASA Astrophysics Data System (ADS)

Wei, Y.; Thio, H. K.; Chock, G.; Titov, V. V.

2014-12-01

A national standard for engineering design for tsunami effects has not existed before and this significant risk is mostly ignored in engineering design. The American Society of Civil Engineers (ASCE) 7 Tsunami Loads and Effects Subcommittee is completing a chapter for the 2016 edition of ASCE/SEI 7 Standard. Chapter 6, Tsunami Loads and Effects, would become the first national tsunami design provisions. These provisions will apply to essential facilities and critical infrastructure. This standard for tsunami loads and effects will apply to designs as part of the tsunami preparedness. The provisions will have significance as the post-tsunami recovery tool, to plan and evaluate for reconstruction. Maps of 2,500-year probabilistic tsunami inundation for Alaska, Washington, Oregon, California, and Hawaii need to be developed for use with the ASCE design provisions. These new tsunami design zone maps will define the coastal zones where structures of greater importance would be designed for tsunami resistance and community resilience. The NOAA Center for Tsunami Research (NCTR) has developed 75 tsunami inundation models as part of the operational tsunami model forecast capability for the U.S. coastline. NCTR, UW, and URS are collaborating with ASCE to develop the 2,500-year tsunami design maps for the Pacific states using these tsunami models. This ensures the probabilistic criteria are established in ASCE's tsunami design maps. URS established a Probabilistic Tsunami Hazard Assessment approach consisting of a large amount of tsunami scenarios that include both epistemic uncertainty and aleatory variability (Thio et al., 2010). Their study provides 2,500-year offshore tsunami heights at the 100-m water depth, along with the disaggregated earthquake sources. NOAA's tsunami models are used to identify a group of sources that produce these 2,500-year tsunami heights. The tsunami inundation limits and runup heights derived from these sources establish the tsunami design map for the study site. ASCE's Energy Grad Line Analysis then uses these modeling constraints to derive hydrodynamic forces for structures within the tsunami design zone. The probabilistic tsunami design maps will be validated by comparison to state inundation maps under the coordination of the National Tsunami Hazard Mitigation Program.

The EarthScope Plate Boundary Observatory and allied networks, the makings of nascent Earthquake and Tsunami Early Warning System in Western North America.

NASA Astrophysics Data System (ADS)

Mattioli, Glen; Mencin, David; Hodgkinson, Kathleen; Meertens, Charles; Phillips, David; Blume, Fredrick; Berglund, Henry; Fox, Otina; Feaux, Karl

2016-04-01

The NSF-funded GAGE Facility, managed by UNAVCO, operates approximately ~1300 GNSS stations distributed across North and Central America and in the circum-Caribbean. Following community input starting in 2011 from several workshops and associated reports,UNAVCO has been exploring ways to increase the capability and utility of the geodetic resources under its management to improve our understanding in diverse areas of geophysics including properties of seismic, volcanic, magmatic and tsunami deformation sources. Networks operated by UNAVCO for the NSF have the potential to profoundly transform our ability to rapidly characterize events, provide rapid characterization and warning, as well as improve hazard mitigation and response. Specific applications currently under development include earthquake early warning, tsunami early warning, and tropospheric modeling with university, commercial, non-profit and government partners on national and international scales. In the case of tsunami early warning, for example, an RT-GNSS network can provide multiple inputs in an operational system starting with rapid assessment of earthquake sources and associated deformation, which leads to the initial model of ocean forcing and tsunami generation. In addition, terrestrial GNSScan provide direct measurements of the tsunami through the associated traveling ionospheric disturbance from several 100's of km away as they approach the shoreline,which can be used to refine tsunami inundation models. Any operational system like this has multiple communities that rely on a pan-Pacific real-time open data set. Other scientific and operational applications for high-rate GPS include glacier and ice sheet motions, tropospheric modeling, and better constraints on the dynamics of space weather. Combining existing data sets and user communities, for example seismic data and tide gauge observations, with GNSS and Met data products has proven complicated because of issues related to metadata, appropriate data formats, data quality assessment in real-time and other issues related to using these products operational forecasting. While progress has been made toward more open and free data access across national borders and toward more cooperation among cognizant government sanctioned "early warning" agencies, some impediments remain making a truly operational system a work in progress. Accordingly, UNAVCO has embarked on significant improvements and improvement goals to the original infrastructure and scope of the PBO. We anticipate that PBO and related networks will form a backbone for these disparate efforts providing high quality, low latency raw and processed GNSS data. This requires substantial upgrades to the entire system from the basic GNNS receiver, through robust data collection, archiving and open distribution mechanisms, to efficient data-processing strategies. UNAVCO is currently in a partnership with the commercial and scientific stakeholders to define, develop and deploy all segments of this improved geodetic network. We present the overarching goals, and current and planned future stateof this international resource.

Risk communication, geoethics and decision science issues in Japan's disaster management system

NASA Astrophysics Data System (ADS)

Sugimoto, M.

2014-12-01

Issues in Japan's disaster management system were revealed by the 2011 Tohoku earthquake and tsunami, and by the Fukushima Dai-ichi nuclear power station accident. Many important decisions were based on scientific data, but appear not to have sufficiently considered the uncertainties of the data and the societal aspects of the problems. The issues that arose show the need for scientists to appropriately deal with risk communication and geoethics and issues. This paper discusses necessity of　education for risk communication, geoethics and decisions science in school before students become sicentific decision makers in future.

Tsunami Waves Joint Inversion Using Tsunami Inundation, Tsunami Deposits Distribution and Marine-Terrestrial Sediment Signal in Tsunami Deposit

NASA Astrophysics Data System (ADS)

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.

Worldwide Emerging Environmental Issues Affecting the U.S. Military. March 2011 Report

DTIC Science & Technology

2011-03-01

nuclear plant http://abcnews.go.com/Business/wireStory?id=13241596 Detection of radioactive material in the soil in Fukushima Daiichi Nuclear Power...and Nuclear Disasters in Japan The important reassessments following the Tōhoku earthquake and tsunami that hit Japan‟s northeast coast on March 11...and the nuclear waste issues are still not solved; hence, the Fukushima disaster might trigger important regime and development changes, such as

Landquake dynamics inferred from seismic source inversion: Greenland and Sichuan events of 2017

NASA Astrophysics Data System (ADS)

Chao, W. A.

2017-12-01

In June 2017 two catastrophic landquake events occurred in Greenland and Sichuan. The Greenland event leads to tsunami hazard in the small town of Nuugaarsiaq. A landquake in Sichuan hit the town, which resulted in over 100 death. Both two events generated the strong seismic signals recorded by the real-time global seismic network. I adopt an inversion algorithm to derive the landquake force time history (LFH) using the long-period waveforms, and the landslide volume ( 76 million m3) can be rapidly estimated, facilitating the tsunami-wave modeling for early warning purpose. Based on an integrated approach involving tsunami forward simulation and seismic waveform inversion, this study has significant implications to issuing actionable warnings before hazardous tsunami waves strike populated areas. Two single-forces (SFs) mechanism (two block model) yields the best explanation for Sichuan event, which demonstrates that secondary event (seismic inferred volume: 8.2 million m3) may be mobilized by collapse-mass hitting from initial rock avalanches ( 5.8 million m3), likely causing a catastrophic disaster. The later source with a force magnitude of 0.9967×1011 N occurred 70 seconds after first mass-movement occurrence. In contrast, first event has the smaller force magnitude of 0.8116×1011 N. In conclusion, seismically inferred physical parameters will substantially contribute to improving our understanding of landquake source mechanisms and mitigating similar hazards in other parts of the world.

Community clusters of tsunami vulnerability in the US Pacific Northwest

PubMed Central

Wood, Nathan J.; Jones, Jeanne; Spielman, Seth; Schmidtlein, Mathew C.

2015-01-01

Many coastal communities throughout the world are threatened by local (or near-field) tsunamis that could inundate low-lying areas in a matter of minutes after generation. Although the hazard and sustainability literature often frames vulnerability conceptually as a multidimensional issue involving exposure, sensitivity, and resilience to a hazard, assessments often focus on one element or do not recognize the hazard context. We introduce an analytical framework for describing variations in population vulnerability to tsunami hazards that integrates (i) geospatial approaches to identify the number and characteristics of people in hazard zones, (ii) anisotropic path distance models to estimate evacuation travel times to safety, and (iii) cluster analysis to classify communities with similar vulnerability. We demonstrate this approach by classifying 49 incorporated cities, 7 tribal reservations, and 17 counties from northern California to northern Washington that are directly threatened by tsunami waves associated with a Cascadia subduction zone earthquake. Results suggest three primary community groups: (i) relatively low numbers of exposed populations with varied demographic sensitivities, (ii) high numbers of exposed populations but sufficient time to evacuate before wave arrival, and (iii) moderate numbers of exposed populations but insufficient time to evacuate. Results can be used to enhance general hazard-awareness efforts with targeted interventions, such as education and outreach tailored to local demographics, evacuation training, and/or vertical evacuation refuges. PMID:25870283

On the Development of Multi-Hazard Early Warning Networks: Practical experiences from North and Central America.

NASA Astrophysics Data System (ADS)

Mencin, David; Hodgkinson, Kathleen; Braun, John; Meertens, Charles; Mattioli, Glen; Phillips, David; Blume, Fredrick; Berglund, Henry; Fox, Otina; Feaux, Karl

2015-04-01

The GAGE facility, managed by UNAVCO, maintains and operates about 1300 GNSS stations distributed across North and Central America as part of the EarthScope Plate Boundary Observatory (PBO) and the Continuously Operating Caribbean GPS Observational Network (COCONet). UNAVCO has upgraded about 450 stations in these networks to real-time and high-rate (RT-GNSS) and included surface meteorological instruments. The majority of these streaming stations are part of the PBO but also include approximately 50 RT-GNSS stations in the Caribbean and Central American region as part of the COCONet and TLALOCNet projects. Based on community input UNAVCO has been exploring ways to increase the capability and utility of these resources to improve our understanding in diverse areas of geophysics including seismic, volcanic, magmatic and tsunami deformation sources, extreme weather events such as hurricanes and storms, and space weather. The RT-GNSS networks also have the potential to profoundly transform our ability to rapidly characterize geophysical events, provide early warning, as well as improve hazard mitigation and response. Specific applications currently under development with university, commercial, non-profit and government collaboration on national and international scales include earthquake and tsunami early warning systems and near real-time tropospheric modeling of hurricanes and precipitable water vapor estimate assimilation. Using tsunami early warning as an example, an RT-GNSS network can provide multiple inputs in an operational system starting with rapid assessment of earthquake sources and associated deformation which informs the initial modeled tsunami. The networks can then can also provide direct measurements of the tsunami wave heights and propagation by tracking the associated ionospheric disturbance from several 100's of km away as the waves approaches the shoreline. These GNSS based constraints can refine the tsunami and inundation models and potentially mitigate hazards. Other scientific and operational applications for high-rate GPS include glacier and ice sheet motions, tropospheric modeling, and better constraints on the dynamics of space weather. Our operational system has multiple communities that use and depend on a Pan-Pacific real-time open data set. The ability to merge existing data sets and user communities, seismic and tide gauge observations, with GNSS and Met data products has proven complicated because of issues related to meta-data, appropriate data formats, data quality assessment in real-time and specific issues related to using these products in operational forecasting. Additional issues related to data access across national borders and cognizant government sanctioned "early warning" agencies, some committed to specific technologies, methodologies, internal structure and further constrained by data policies make a truly operational system an on-going work in progress. We present a short history of evolving a very large and expensive RT-GNSS network originally designed to answer specific long term scientific questions about structure and evolution of North American plate boundaries into a much needed national hazard system while continuing to serve our core community in long term scientific studies. Out primary focus in this presentation is an analysis of our current goals and impediments to achieving these broader objectives.

A short history of tsunami research and countermeasures in Japan.

PubMed

Shuto, Nobuo; Fujima, Koji

2009-01-01

The tsunami science and engineering began in Japan, the country the most frequently hit by local and distant tsunamis. The gate to the tsunami science was opened in 1896 by a giant local tsunami of the highest run-up height of 38 m that claimed 22,000 lives. The crucial key was a tide record to conclude that this tsunami was generated by a "tsunami earthquake". In 1933, the same area was hit again by another giant tsunami. A total system of tsunami disaster mitigation including 10 "hard" and "soft" countermeasures was proposed. Relocation of dwelling houses to high ground was the major countermeasures. The tsunami forecasting began in 1941. In 1960, the Chilean Tsunami damaged the whole Japanese Pacific coast. The height of this tsunami was 5-6 m at most. The countermeasures were the construction of structures including the tsunami breakwater which was the first one in the world. Since the late 1970s, tsunami numerical simulation was developed in Japan and refined to become the UNESCO standard scheme that was transformed to 22 different countries. In 1983, photos and videos of a tsunami in the Japan Sea revealed many faces of tsunami such as soliton fission and edge bores. The 1993 tsunami devastated a town protected by seawalls 4.5 m high. This experience introduced again the idea of comprehensive countermeasures, consisted of defense structure, tsunami-resistant town development and evacuation based on warning.

Development of a Probabilistic Tsunami Hazard Analysis in Japan

DOE Office of Scientific and Technical Information (OSTI.GOV)

Toshiaki Sakai; Tomoyoshi Takeda; Hiroshi Soraoka

2006-07-01

It is meaningful for tsunami assessment to evaluate phenomena beyond the design basis as well as seismic design. Because once we set the design basis tsunami height, we still have possibilities tsunami height may exceeds the determined design tsunami height due to uncertainties regarding the tsunami phenomena. Probabilistic tsunami risk assessment consists of estimating for tsunami hazard and fragility of structures and executing system analysis. In this report, we apply a method for probabilistic tsunami hazard analysis (PTHA). We introduce a logic tree approach to estimate tsunami hazard curves (relationships between tsunami height and probability of excess) and present anmore » example for Japan. Examples of tsunami hazard curves are illustrated, and uncertainty in the tsunami hazard is displayed by 5-, 16-, 50-, 84- and 95-percentile and mean hazard curves. The result of PTHA will be used for quantitative assessment of the tsunami risk for important facilities located on coastal area. Tsunami hazard curves are the reasonable input data for structures and system analysis. However the evaluation method for estimating fragility of structures and the procedure of system analysis is now being developed. (authors)« less

Tsunami Science for Society

NASA Astrophysics Data System (ADS)

Bernard, E. N.

2014-12-01

As the decade of mega-tsunamis has unfolded with new data, the science of tsunami has advanced at an unprecedented pace. Our responsibility to society should guide the use of these new scientific discoveries to better prepare society for the next tsunami. This presentation will focus on the impacts of the 2004 and 2011 tsunamis and new societal expectations accompanying enhanced funding for tsunami research. A list of scientific products, including tsunami hazard maps, tsunami energy scale, real-time tsunami flooding estimates, and real-time current velocities in harbors will be presented to illustrate society's need for relevant, easy to understand tsunami information. Appropriate use of these tsunami scientific products will be presented to demonstrate greater tsunami resilience for tsunami threatened coastlines. Finally, a scientific infrastructure is proposed to ensure that these products are both scientifically sound and represent today's best practices to protect the scientific integrity of the products as well as the safety of coastal residents.

Development of Spaceborne Radar Simulator by NICT and JAXA using JMA Cloud-resolving Model

NASA Astrophysics Data System (ADS)

Kubota, T.; Eito, H.; Aonashi, K.; Hashimoto, A.; Iguchi, T.; Hanado, H.; Shimizu, S.; Yoshida, N.; Oki, R.

2009-12-01

We are developing synthetic spaceborne radar data toward a simulation of the Dual-frequency Precipitation Radar (DPR) aboard the Global Precipitation Measurement (GPM) core-satellite. Our purposes are a production of test-bed data for higher level DPR algorithm developers, in addition to a diagnosis of a cloud resolving model (CRM). To make the synthetic data, we utilize the CRM by the Japan Meteorological Agency (JMA-NHM) (Ikawa and Saito 1991, Saito et al. 2006, 2007), and the spaceborne radar simulation algorithm by the National Institute of Information and Communications Technology (NICT) and the Japan Aerospace Exploration Agency (JAXA) named as the Integrated Satellite Observation Simulator for Radar (ISOSIM-Radar). The ISOSIM-Radar simulates received power data in a field of view of the spaceborne radar with consideration to a scan angle of the radar (Oouchi et al. 2002, Kubota et al. 2009). The received power data are computed with gaseous and hydrometeor attenuations taken into account. The backscattering and extinction coefficients are calculated assuming the Mie approximation for all species. The dielectric constants for solid particles are computed by the Maxwell-Garnett model (Bohren and Battan 1982). Drop size distributions are treated in accordance with those of the JMA-NHM. We assume a spherical sea surface, a Gaussian antenna pattern, and 49 antenna beam directions for scan angles from -17 to 17 deg. in the PR. In this study, we report the diagnosis of the JMA-NHM with reference to the TRMM Precipitation Radar (PR) and CloudSat Cloud Profiling Radar (CPR) using the ISOSIM-Radar from the view of comparisons in cloud microphysics schemes of the JMA-NHM. We tested three kinds of explicit bulk microphysics schemes based on Lin et al. (1983), that is, three-ice 1-moment scheme, three-ice 2-moment scheme (Eito and Aonashi 2009), and newly developed four-ice full 2-moment scheme (Hashimoto 2008). The hydrometeor species considered here are rain, graupel, snow, cloud water, cloud ice and hail (4-ice scheme only). We examined a case of an intersection with the TRMM PR and the CloudSat CPR on 6th April 2008 over sea surface in the south of Kyushu Island of Japan. In this work, observed rainfall systems are simulated with one-way double nested domains having horizontal grid sizes of 5 km (outer) and 2 km (inner). Data used here are from the inner domain only. Results of the PR indicated better performances of 2-moment bulk schemes. It suggests that prognostic number concentrations of frozen hydrometeors are more effective in high altitudes and constant number concentrations can lead to the overestimation of the snow there. For three-ice schemes, simulated received power data overestimated above freezing levels with reference to the observed data. In contrast, the overestimation of frozen particles was heavily reduced for the four-ice scheme.

Class Room Exercises Using JMA-59-Type Seismograms for Earthquake Study at High-School Level

NASA Astrophysics Data System (ADS)

Okamoto, Y.; Furuta, S.; Hirota, N.

2013-12-01

The JMA-59-type electromagnetic seismograph was the standard seismograph for routine observations by the Japan Meteorological Agency (JMA) from the 1960's to the 1990's. Some features of those seismograms include 1) displacement wave records (electrically integrated from a velocity output by a moving-coil-type sensor), 2) ink records on paper (analog recording with time marks), 3) continuous drum recording for 12 h, and 4) lengthy operation time over several decades. However, the digital revolution in recording systems during the 1990's made these analog features obsolete, and their abundant and bulky paper-based records were stacked and sometimes disregarded in the library of every observatory. Interestingly, from an educational aspect, the disadvantages of these old-fashioned systems become highly advantageous for educational or outreach purposes. The updated digital instrument is essentially a 'black-box,' not revealing its internal mechanisms and being too fast for observing its signal processes. While the old seismometers and recording systems have been disposed of long since, stacks of analog seismograms continue to languish in observatories' back rooms. In our study, we develop some classroom exercises for studying earthquakes at the mid- to high-school level using these analog seismograms. These exercises include 1) reading the features of seismic records, 2) measuring the S-P time, 3) converting the hypocentral distance from Omori's distance formula, 4) locating the epicenter/hypocenter using the S-P times of surrounding stations, and 5) estimating earthquake magnitude using the Tsuboi's magnitude formula. For this calculation we developed a 'nomogram'--a graphical paper calculator created using a Python-based freeware tool named 'PyNomo.' We tested many seismograms and established the following rules: 1) shallow earthquakes are appropriate for using the Tsuboi's magnitude formula; 2) there is no saturation at peak amplitude; 3) seismograms make it easy to read S-P time and maximum amplitude; 4) they also make it is easy to locate an earthquake's hypocenter. For advanced study, particularly of the source mechanisms of earthquakes, P-wave arrival phases are typically determined from wave records. In this exercise, we use displacement-based records for use by students for recognizing these arrival phases directly rather than by using velocity or acceleration records. Following are some advantages of using these JMA-59-type seismograms: 1) displacement records are easy to compare with real ground motion; 2) ink records can help young students visualize the analog images of a legacy seismograph; 3) scale dimensions such as amplitude of 100 times and time scale of 1 mm/s are easy to explain while using these seismograms as an exercise resource. We confirmed the availability of our exercises by cooperation with our high-school students. We will offer some practical examples at the conference. Keywords: JMA-59 type seismograph, seismograms, hypocenter location, magnitude estimation, educational tool, classroom exercise, high-school

Geological evidence for Holocene earthquakes and tsunamis along the Nankai-Suruga Trough, Japan

NASA Astrophysics Data System (ADS)

Garrett, Ed; Fujiwara, Osamu; Garrett, Philip; Heyvaert, Vanessa M. A.; Shishikura, Masanobu; Yokoyama, Yusuke; Hubert-Ferrari, Aurélia; Brückner, Helmut; Nakamura, Atsunori; De Batist, Marc

2016-04-01

The Nankai-Suruga Trough, lying immediately south of Japan's densely populated and highly industrialised southern coastline, generates devastating great earthquakes (magnitude > 8). Intense shaking, crustal deformation and tsunami generation accompany these ruptures. Forecasting the hazards associated with future earthquakes along this >700 km long fault requires a comprehensive understanding of past fault behaviour. While the region benefits from a long and detailed historical record, palaeoseismology has the potential to provide a longer-term perspective and additional insights. Here, we summarise the current state of knowledge regarding geological evidence for past earthquakes and tsunamis, incorporating literature originally published in both Japanese and English. This evidence comes from a wide variety of sources, including uplifted marine terraces and biota, marine and lacustrine turbidites, liquefaction features, subsided marshes and tsunami deposits in coastal lakes and lowlands. We enhance available results with new age modelling approaches. While publications describe proposed evidence from > 70 sites, only a limited number provide compelling, well-dated evidence. The best available records allow us to map the most likely rupture zones of eleven earthquakes occurring during the historical period. Our spatiotemporal compilation suggests the AD 1707 earthquake ruptured almost the full length of the subduction zone and that earthquakes in AD 1361 and 684 were predecessors of similar magnitude. Intervening earthquakes were of lesser magnitude, highlighting variability in rupture mode. Recurrence intervals for ruptures of the a single seismic segment range from less than 100 to more than 450 years during the historical period. Over longer timescales, palaeoseismic evidence suggests intervals ranging from 100 to 700 years. However, these figures reflect thresholds of evidence creation and preservation as well as genuine recurrence intervals. At present, we have not identified any geological data that support the occurrence earthquakes of larger magnitude than that experienced in AD 1707; however, few published studies seek to establish the relative magnitudes of different earthquake and tsunami events. Alongside the paucity of research designed to quantify the magnitude of past earthquakes, we emphasise a number of other issues, including alternative hypotheses for proposed palaeoseismic evidence, the lack of robust chronological frameworks and insufficient appreciation of changing thresholds of evidence creation and preservation over time. These key issues must be addressed by future research.

Integrating TWES and Satellite-based remote sensing: Lessons learned from the Honshu 2011 Tsunami

NASA Astrophysics Data System (ADS)

Löwe, Peter; Wächter, Joachim

2013-04-01

The Boxing Day Tsunami killed 240,000 people and inundated the affected shorelines with waves reaching heights up to 30m. Tsunami Early Warning Capabilities have improved in the meantime by continuing development of modular Tsunami Early Warning Systems (TEWS). However, recent tsunami events, like the Chile 2010 and the Honshu 2011 tsunami demonstrate that the key challenge for TEWS research still lies in the timely issuing of reliable early warning messages to areas at risk, but also to other stakeholders professionally involved in the unfolding event. Until now remote sensing products for Tsunami events, including crisis maps and change detection products, are exclusively linked to those phases of the disaster life cycle, which follow after the early warning stage: Response, recovery and mitigation. The International Charter for Space and Major Disasters has been initiated by the European Space Agency (ESA) and the Centre National d'Etudes Spatiales (CNES) in 1999. It coordinates a voluntary group of governmental space agencies and industry partners, to provide rapid crisis imaging and mapping to disaster and relief organisations to mitigate the effects of disasters on human life, property and the environment. The efficiency of this approach has been demonstrated in the field of Tsunami early warning by Charter activations following the Boxing Day Tsunami 2004, the Chile Tsunami 2010 and the Honshu Tsunami 2011. Traditional single-satellite operations allow at best bimonthly repeat rates over a given Area of Interest (AOI). This allows a lot of time for image acquisition campaign planning between imaging windows for the same AOI. The advent of constellations of identical remote sensing satellites in the early 21st century resulted both in daily AOI revisit capabilities and drastically reduced time frames for acquisition planning. However, the image acquisition planning for optical remote sensing satellite constellations is constrained by orbital and communication requirements: Defined time slots exist to commandeer the tasking of image acquisitions. If such a time slot has been missed, another attempt to image an AOI again can only be attempted ca. 24 hours later, due to the sun-synchronous satellite orbits Therefore it is critical to establish automated Disaster Early Warning dissemination services for the remote sensing community, to supply them with the timeliest opportunity to trigger the tasking process for the affected AOI. For very large events like a Tsunami in the Pacific, this approach provides the chance to gain additional pre-disaster imagery as a reference for change detection. In the case of the Tohoku earthquake, an ad-hoc warning dissemination process was manually dispatched by the Centre for Geoinformation Technology (CeGIT) at the German Research Centre for Geoscience, contacting RapidEye AG, once the severity of the earthquake event had been confirmed by the GEOFON geoseismic network. RapidEye AG decided to launch an imaging campaign which yielded 78 georectified image tiles (L3A) of Honshu island during the next imaging window. Of these, 26 tiles cover the affected coastline, resulting in 16,250km² of content for crisis mapping effort such as the Humanitarian Open Street Map (OSM) Team. This data was made available by RapidEye as a part of the Charter Activiation requested by Japan on March 11 2011. [1] Hoja, D., Schwinger, M.,Wendleder A.,Löwe, P., Konstanski, H., Weichelt, H.: Optimised Near-Real Time Data Acquisition for Disaster Related Rapid Mapping

The role of integrating natural and social science concepts for risk governance and the design of people-centred early warning systems. Case study from the German-Indonesian Tsunami Early Warning System Project (GITEWS)

NASA Astrophysics Data System (ADS)

Gebert, Niklas; Post, Joachim

2010-05-01

The development of early warning systems are one of the key domains of adaptation to global environmental change and contribute very much to the development of societal reaction and adaptive capacities to deal with extreme events. Especially, Indonesia is highly exposed to tsunami. In average every three years small and medium size tsunamis occur in the region causing damage and death. In the aftermath of the Indian Ocean Tsunami 2004, the German and Indonesian government agreed on a joint cooperation to develop a People Centered End-to-End Early Warning System (GITEWS). The analysis of risk and vulnerability, as an important step in risk (and early warning) governance, is a precondition for the design of effective early warning structures by delivering the knowledge base for developing institutionalized quick response mechanisms of organizations involved in the issuing of a tsunami warning, and of populations exposed to react to warnings and to manage evacuation before the first tsunami wave hits. Thus, a special challenge for developing countries is the governance of complex cross-sectoral and cross-scale institutional, social and spatial processes and requirements for the conceptualization, implementation and optimization of a people centered tsunami early warning system. In support of this, the risk and vulnerability assessment of the case study aims at identifying those factors that constitute the causal structure of the (dis)functionality between the technological warning and the social response system causing loss of life during an emergency situation: Which social groups are likely to be less able to receive and respond to an early warning alert? And, are people able to evacuate in due time? Here, only an interdisciplinary research approach is capable to analyze the socio-spatial and environmental conditions of vulnerability and risk and to produce valuable results for decision makers and civil society to manage tsunami risk in the early warning context. This requires the integration of natural / spatial and social science concepts, methods and data: E.g. a scenario based approach for tsunami inundation modeling was developed to provide decision makers with options to decide up to what level they aim to protect their people and territory, on the contrary household surveys were conducted for the spatial analysis of the evacuation preparedness of the population as a function of place specific hazard, risk, warning and evacuation perception; remote sensing was applied for the spatial analysis (land-use) of the socio-physical conditions of a city and region for evacuation; and existing social / population statistics were combined with land-use data for the precise spatial mapping of the population exposed to tsunami risks. Only by utilizing such a comprehensive assessment approach valuable information for risk governance can be generated. The results are mapped using GIS and designed according to the specific needs of different end-users, such as public authorities involved in the design of warning dissemination strategies, land-use planners (shelter planning, road network configuration) and NGOs mandated to provide education for the general public on tsunami risk and evacuation behavior. The case study of the city of Padang (one of the pilot areas of GITEWS), Indonesia clearly show, that only by intersecting social (vulnerability) and natural hazards research a comprehensive picture on tsunami risk can be provided with which risk governance in the early warning context can be conducted in a comprehensive, systemic and sustainable manner.

The September 16, 2015 Illapel Tsunami - Sedimentology of tsunami deposits at the beaches of La Serena and Coquimbo

NASA Astrophysics Data System (ADS)

Bahlburg, Heinrich; Nentwig, Vanessa; Matthias, Kreutzer

2016-04-01

On September 16, 2015, at 7:54 pm local time, an earthquake with Mw 8.3 occurred off the coast of Central Chile, 46 km west of the town of Illapel. Its hypocenter was located at a depth of 8.7 km in the transition zone from the Chilean flat slab to the central Chilean steep slab subduction geometry, and near the intersection of the Juan Fernandez Ridge with the South America plate. The quake caused a predominantly minor tsunami between Caldera (c. 27°S) and Los Vilos (c. 32°S). Only at Coquimbo and La Serena (c. 30°S) did the tsunami attain large wave heights on the order of 4.5 m leading to flooding and destruction of infrastructure. Maximum inundation distance was c. 700 m at Playa Changa, Coquimbo Bay. Minor flooding occurred along the northward adjacent beaches of La Serena reaching inundation distances of up to 150 m. Tsunami deposits are usually the only observable evidence of past events. To understand how tsunami deposits form and are preserved, and how they can be identified in the geological record, it is of paramount importance to undertake detailed studies in the wake of actual events. Here we report initial field data of a sedimentological post-tsunami field survey undertaken in October 2015. The most comprehensive and instructive sedimentological record of the September 16, 2015 tsunami is preserved at Playa Los Fuertes in La Serena. Along a 30 m long trench perpendicular to the coast we observed a laminated package of tsunami deposits of varying thickness. The deposits have an erosive basal unconformity with an amplitude of at least 10 cm. The preserved deposit thickness varies between 10 an 50 cm. The deposit consists of 7 layers of variable thickness, ranging between dark laminae a few millimeters thick and rich in heavy minerals, and lighter colored sand layers up to 15 cm thick. Grain size distributions are moderately well to well sorted and unimodal with modes between 1.3 and 2.0 Φ (medium sand). A c. 10 cm thick laminated layer in the central part of the vertical section includes mildly trough-shaped crossbeds indicating landward flow, a c. 5 cm thick layer 10 cm below the top in the interior part of the trench contains planar cross beds formed by outflow currents. Water escape occur as small sand diapirs and volcanoes within the final deposit. Water escape through small volcanoes appears to have been coeval to formation of the overlying layer by traction deposition as sand issuing from the lower layer has been preserved as a thin plume deformed in the downcurrent, i.e. landward, direction in the newly forming upper layer. Other sectors of the sediment show sand diapirs intruding up to 15 cm into the overlying tsunami deposit. The assemblage of laminae, layers and sedimentary structures indicates that the deposit records at least two events of tsunami inflow indicated by crossbeds and deformed sand volcano plumes, and one outflow event. Intervening layers without directional structures can not be assigned unequivocally to either inflow or outflow deposition.

Tsunami Early Warning System in Italy and involvement of local communities

NASA Astrophysics Data System (ADS)

Tinti, Stefano; Armigliato, Alberto; Zaniboni, Filippo

2010-05-01

Italy is characterized by a great coastal extension, and by a series of possible tsunamigenic sources: many active faults, onshore and offshore, also near the shoreline and in shallow water, active volcanoes (Etna, Stromboli, Campi Flegrei for example), continental margins where landslides can occur. All these threats justify the establishment of a tsunami early warning system (TEWS), especially in Southern Italy where most of the sources capable of large disastrous tsunamis are located. One of the main characteristics of such sources, that however is common to other countries in not only in the Mediterranean, is their vicinity to the coast, which means that the tsunami lead time for attacking the coastal system is expected to be within 10-15 minutes in several cases. This constraint of time imposes to conceive and adopt specific plans aiming at a quick tsunami detection and alert dissemination for the TEWS, since obviously the TEWS alert must precede and not follow the tsunami first arrival. The need to be quick introduces the specific problem of uncertainty that is though inherent to any forecast system, but it is a very big issue especially when time available is short, since crucial decisions have to be taken in presence of incomplete data and incomplete processing. This is just the big problem that has to be faced by a system like the a TEWS in Italy. Uncertainties can be reduced by increasing the capabilities of the tsunami monitoring system by densifying the traditional instrumental networks (e.g. by empowering seismic and especially coastal and offshore sea-level observation systems) in the identified tsunamigenic source areas. However, uncertainties, though are expected to have a decreasing trend as time passes after the tsunami initiation, cannot be eliminated and have to be appropriately dealt with: uncertainties lead to under- and overestimation of the tsunami size and arrival times, and to missing or to false alerts, or in other terms they degrade the performance of the tsunami predictors. The role of the local communities in defining the strategies in case of uncertain data is essential: only involvement of such communities since the beginning of the planning and implementation phase of the TEWS as well as in the definition of a decision making matrix can ensure appropriate response in case of emergency, and most importantly, the acceptance of the system in the long run. The efforts to implement the Tsunami Warning System in Italy should take into proper account the above mentioned aspects. Involvement of local communities should be primarily realized through the involvement of the local components of the Civil Protection Agency that is responsible for the implementation of the system over the Italian territory. A pilot project is being conducted in cooperation between the Civil Protection Service of Sicily and the University of Bologna (UNIBO) that contemplates the empowering of the local sea-level monitoring system (TSUNET) and specific vulnerability and risk analyses, also exploiting results of national and European research projects (e.g. TRANSFER and SCHEMA) where UNIBO had a primary role.

Asian tsunami relief: Department of Defense public health response: policy and strategic coordination considerations.

PubMed

Tarantino, Dave

2006-10-01

The Asian tsunami of December 26, 2004, was one of the most devastating natural disasters in modern history. In particular, this disaster created massive, unique, public health threats, necessitating equally massive public health response efforts. The U.S. government (USG), including the Department of Defense (DoD), played a pivotal role in the response. This article examines some of the central policy issues and strategic coordination and planning measures involved in the public health response. The nearly unanimous consensus of international public health experts has been that the potential public health crisis in the aftermath of the Asian tsunami was averted largely because of the coordinated efforts of host nation officials and professionals, international and nongovernmental health organizations, and bilateral donors, especially the USG, including the DoD. The DoD played a central role in public health efforts through coordination and communication assistance, logistical and materiel support, disease surveillance activities, health needs assessments, and the contributions of the USS Mercy hospital ship. The core lessons involve the importance of an early, dedicated, public health response as a component of the overall disaster relief effort, as well as seamless coordination of health sector stakeholders in the USG and with those of the international community and affected host nations, which allows each organization to play to its strengths and to avoid duplication. The Asian tsunami relief effort highlighted the value of civil-military cooperation in disaster relief, particularly in the area of public health. The prominent role of the DoD in tsunami relief efforts, including public health efforts, also yielded beneficial secondary effects by bolstering security cooperation and winning "hearts and minds" in the region.

Numerical experiment on tsunami deposit distribution process by using tsunami sediment transport model in historical tsunami event of megathrust Nankai trough earthquake

NASA Astrophysics Data System (ADS)

Imai, K.; Sugawara, D.; Takahashi, T.

2017-12-01

A large flow caused by tsunami transports sediments from beach and forms tsunami deposits in land and coastal lakes. A tsunami deposit has been found in their undisturbed on coastal lakes especially. Okamura & Matsuoka (2012) found some tsunami deposits in the field survey of coastal lakes facing to the Nankai trough, and tsunami deposits due to the past eight Nankai Trough megathrust earthquakes they identified. The environment in coastal lakes is stably calm and suitable for tsunami deposits preservation compared to other topographical conditions such as plains. Therefore, there is a possibility that the recurrence interval of megathrust earthquakes and tsunamis will be discussed with high resolution. In addition, it has been pointed out that small events that cannot be detected in plains could be separated finely (Sawai, 2012). Various aspects of past tsunami is expected to be elucidated, in consideration of topographical conditions of coastal lakes by using the relationship between the erosion-and-sedimentation process of the lake bottom and the external force of tsunami. In this research, numerical examination based on tsunami sediment transport model (Takahashi et al., 1999) was carried out on the site Ryujin-ike pond of Ohita, Japan where tsunami deposit was identified, and deposit migration analysis was conducted on the tsunami deposit distribution process of historical Nankai Trough earthquakes. Furthermore, examination of tsunami source conditions is possibly investigated by comparison studies of the observed data and the computation of tsunami deposit distribution. It is difficult to clarify details of tsunami source from indistinct information of paleogeographical conditions. However, this result shows that it can be used as a constraint condition of the tsunami source scale by combining tsunami deposit distribution in lakes with computation data.

Analysis of fatigue characteristic of sm-substituted DyFeCo magneto-optical films

NASA Astrophysics Data System (ADS)

Li, Zuoyi; Wang, Ke; Yang, Xiaofei; Li, Zhen; Lin, Gengqi

2003-04-01

The fatigue characteristic of the amorphous Sm-substituted DyFeCo magneto-optical alloy films fabricated by R.F. magnetron sputtering method were investigated by accelerated pulse training method under the condition of magnetic field modulation plus laser pulse irradiation. The evaluation of fatigue characteristic is determined from the static magneto-optical signal readout level after several writing/erasing repetitions compared with initial level. The experimental dependence of fatigue characteristics is in good agreement with the model based on the JMA equation. Furthermore, the Avrami factor can be derived from the model. Experimental results show that it is very effective in studying the writing/erasing ability of magneto-optical films employed the method of combined the accelerated pulse training with the JMA equation and Sm-substituted HRE-TM alloys can act as a practical medium for MO storage at short wavelength.

A short history of tsunami research and countermeasures in Japan

PubMed Central

Shuto, Nobuo; Fujima, Koji

2009-01-01

The tsunami science and engineering began in Japan, the country the most frequently hit by local and distant tsunamis. The gate to the tsunami science was opened in 1896 by a giant local tsunami of the highest run-up height of 38 m that claimed 22,000 lives. The crucial key was a tide record to conclude that this tsunami was generated by a “tsunami earthquake”. In 1933, the same area was hit again by another giant tsunami. A total system of tsunami disaster mitigation including 10 “hard” and “soft” countermeasures was proposed. Relocation of dwelling houses to high ground was the major countermeasures. The tsunami forecasting began in 1941. In 1960, the Chilean Tsunami damaged the whole Japanese Pacific coast. The height of this tsunami was 5–6 m at most. The countermeasures were the construction of structures including the tsunami breakwater which was the first one in the world. Since the late 1970s, tsunami numerical simulation was developed in Japan and refined to become the UNESCO standard scheme that was transformed to 22 different countries. In 1983, photos and videos of a tsunami in the Japan Sea revealed many faces of tsunami such as soliton fission and edge bores. The 1993 tsunami devastated a town protected by seawalls 4.5 m high. This experience introduced again the idea of comprehensive countermeasures, consisted of defense structure, tsunami-resistant town development and evacuation based on warning. PMID:19838008

Model validation and error estimation of tsunami runup using high resolution data in Sadeng Port, Gunungkidul, Yogyakarta

NASA Astrophysics Data System (ADS)

Basith, Abdul; Prakoso, Yudhono; Kongko, Widjo

2017-07-01

A tsunami model using high resolution geometric data is indispensable in efforts to tsunami mitigation, especially in tsunami prone areas. It is one of the factors that affect the accuracy results of numerical modeling of tsunami. Sadeng Port is a new infrastructure in the Southern Coast of Java which could potentially hit by massive tsunami from seismic gap. This paper discusses validation and error estimation of tsunami model created using high resolution geometric data in Sadeng Port. Tsunami model validation uses the height wave of Tsunami Pangandaran 2006 recorded by Tide Gauge of Sadeng. Tsunami model will be used to accommodate the tsunami numerical modeling involves the parameters of earthquake-tsunami which is derived from the seismic gap. The validation results using t-test (student) shows that the height of the tsunami modeling results and observation in Tide Gauge of Sadeng are considered statistically equal at 95% confidence level and the value of the RMSE and NRMSE are 0.428 m and 22.12%, while the differences of tsunami wave travel time is 12 minutes.

Magnitude scale for the Central American tsunamis

NASA Astrophysics Data System (ADS)

Hatori, Tokutaro

1995-09-01

Based on the tsunami data in the Central American region, the regional characteristic of tsunami magnitude scales is discussed in relation to earthquake magnitudes during the period from 1900 to 1993. Tsunami magnitudes on the Imamura-Iida scale of the 1985 Mexico and 1992 Nicaragua tsunamis are determined to be m=2.5, judging from the tsunami height-distance diagram. The magnitude values of the Central American tsunamis are relatively small compared to earthquakes with similar size in other regions. However, there are a few large tsunamis generated by low-frequency earthquakes such as the 1992 Nicaragua earthquake. Inundation heights of these unusual tsunamis are about 10 times higher than those of normal tsunamis for the same earthquake magnitude ( M s =6.9 7.2). The Central American tsunamis having magnitude m>1 have been observed by the Japanese tide stations, but the effect of directivity toward Japan is very small compared to that of the South American tsunamis.

Correlation Equation of Fault Size, Moment Magnitude, and Height of Tsunami Case Study: Historical Tsunami Database in Sulawesi

NASA Astrophysics Data System (ADS)

Julius, Musa, Admiral; Pribadi, Sugeng; Muzli, Muzli

2018-03-01

Sulawesi, one of the biggest island in Indonesia, located on the convergence of two macro plate that is Eurasia and Pacific. NOAA and Novosibirsk Tsunami Laboratory show more than 20 tsunami data recorded in Sulawesi since 1820. Based on this data, determination of correlation between tsunami and earthquake parameter need to be done to proved all event in the past. Complete data of magnitudes, fault sizes and tsunami heights on this study sourced from NOAA and Novosibirsk Tsunami database, completed with Pacific Tsunami Warning Center (PTWC) catalog. This study aims to find correlation between moment magnitude, fault size and tsunami height by simple regression. The step of this research are data collecting, processing, and regression analysis. Result shows moment magnitude, fault size and tsunami heights strongly correlated. This analysis is enough to proved the accuracy of historical tsunami database in Sulawesi on NOAA, Novosibirsk Tsunami Laboratory and PTWC.

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

NASA Astrophysics Data System (ADS)

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.

Multiple Solutions of Real-time Tsunami Forecasting Using Short-term Inundation Forecasting for Tsunamis Tool

NASA Astrophysics Data System (ADS)

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.

Evaluation of quantitative precipitation forecasts by TIGGE ensembles for south China during the presummer rainy season

NASA Astrophysics Data System (ADS)

Huang, Ling; Luo, Yali

2017-08-01

Based on The Observing System Research and Predictability Experiment Interactive Grand Global Ensemble (TIGGE) data set, this study evaluates the ability of global ensemble prediction systems (EPSs) from the European Centre for Medium-Range Weather Forecasts (ECMWF), U.S. National Centers for Environmental Prediction, Japan Meteorological Agency (JMA), Korean Meteorological Administration, and China Meteorological Administration (CMA) to predict presummer rainy season (April-June) precipitation in south China. Evaluation of 5 day forecasts in three seasons (2013-2015) demonstrates the higher skill of probability matching forecasts compared to simple ensemble mean forecasts and shows that the deterministic forecast is a close second. The EPSs overestimate light-to-heavy rainfall (0.1 to 30 mm/12 h) and underestimate heavier rainfall (>30 mm/12 h), with JMA being the worst. By analyzing the synoptic situations predicted by the identified more skillful (ECMWF) and less skillful (JMA and CMA) EPSs and the ensemble sensitivity for four representative cases of torrential rainfall, the transport of warm-moist air into south China by the low-level southwesterly flow, upstream of the torrential rainfall regions, is found to be a key synoptic factor that controls the quantitative precipitation forecast. The results also suggest that prediction of locally produced torrential rainfall is more challenging than prediction of more extensively distributed torrential rainfall. A slight improvement in the performance is obtained by shortening the forecast lead time from 30-36 h to 18-24 h to 6-12 h for the cases with large-scale forcing, but not for the locally produced cases.

Management of group b streptococcus-positive pregnant women at maternity homes in JAPAN: a questionnaire survey of compliance among midwives.

PubMed

Yamaguchi, Kotomi; Ohashi, Kazutomo

2018-01-01

Per the 2014 Japanese Midwives Association (JMA) guidelines, midwives were allowed to manage the deliveries for group B streptococcus (GBS)-positive pregnant women in labour at maternity homes without the supervision of a medical doctor if they complied with the guidelines of the Japan Society of Obstetrics and Gynecology (JSOG), wherein midwives working for maternity homes are expected to cooperate with commissioned obstetricians and paediatricians in cooperative medical facilities. We examined the rate of compliance with these JMA and JSOG guidelines regarding the management of GBS-positive pregnant women among midwives at maternity homes in Japan. Between October and December 2015, an anonymous questionnaire was distributed to 337 maternity homes registered with the JMA by mail. The questionnaire obtained information regarding the timing of GBS screening, specimen collection, transfer of GBS-positive pregnant women from a maternity home to a hospital, administration of intrapartum antibiotic prophylaxis, and collaboration between midwives and commissioned obstetricians. Data were analysed using descriptive statistics. We used frequency distribution as the statistical test. Responses were received from 246 (73.0%) maternity homes, of which complete responses from 204 maternity homes (valid response rate, 60.5%) were analysed. Of these 204 maternity homes, only 97 (47.5%) conducted a GBS screening test during 33-37 weeks of gestation as recommended by the JSOG guidelines. Although midwives alone managed GBS-positive pregnant women in labour at 135 maternity homes (66.2%), intrapartum antibiotic prophylaxis, as recommended by the JSOG guidelines, was conducted in only 111 (54.4%). Moreover, only 37.0% (50/135) and 82.2% (111/135) of maternity homes ensured that GBS-positive pregnant women in labour with an elapse of ≥18 h after PROM and a body temperature of ≥38.0 °C, respectively, were transferred to a hospital by ambulance. Only at 58.3% (119/204) of maternity homes did midwives discuss the management of labour for GBS-positive pregnant women with commissioned obstetricians. Some midwives working for maternity homes did not follow the JMA and JSOG guidelines of the management of GBS-positive pregnant women. For improving compliance rates, midwives at maternity homes should discuss the management of GBS-positive pregnant women with commissioned doctors more carefully and concretely per the existing guidelines.

Tsunami.gov: NOAA's Tsunami Information Portal

NASA Astrophysics Data System (ADS)

Shiro, B.; Carrick, J.; Hellman, S. B.; Bernard, M.; Dildine, W. P.

2014-12-01

We present the new Tsunami.gov website, which delivers a single authoritative source of tsunami information for the public and emergency management communities. The site efficiently merges information from NOAA's Tsunami Warning Centers (TWC's) by way of a comprehensive XML feed called Tsunami Event XML (TEX). The resulting unified view allows users to quickly see the latest tsunami alert status in geographic context without having to understand complex TWC areas of responsibility. The new site provides for the creation of a wide range of products beyond the traditional ASCII-based tsunami messages. The publication of modern formats such as Common Alerting Protocol (CAP) can drive geographically aware emergency alert systems like FEMA's Integrated Public Alert and Warning System (IPAWS). Supported are other popular information delivery systems, including email, text messaging, and social media updates. The Tsunami.gov portal allows NOAA staff to easily edit content and provides the facility for users to customize their viewing experience. In addition to access by the public, emergency managers and government officials may be offered the capability to log into the portal for special access rights to decision-making and administrative resources relevant to their respective tsunami warning systems. The site follows modern HTML5 responsive design practices for optimized use on mobile as well as non-mobile platforms. It meets all federal security and accessibility standards. Moving forward, we hope to expand Tsunami.gov to encompass tsunami-related content currently offered on separate websites, including the NOAA Tsunami Website, National Tsunami Hazard Mitigation Program, NOAA Center for Tsunami Research, National Geophysical Data Center's Tsunami Database, and National Data Buoy Center's DART Program. This project is part of the larger Tsunami Information Technology Modernization Project, which is consolidating the software architectures of NOAA's existing TWC's into a single system. We welcome your feedback to help Tsunami.gov become an effective public resource for tsunami information and a medium to enable better global tsunami warning coordination.

Tsunami forecast by joint inversion of real-time tsunami waveforms and seismic of GPS data: application to the Tohoku 2011 tsunami

USGS Publications Warehouse

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.

Tsunami Forecast Progress Five Years After Indonesian Disaster

NASA Astrophysics Data System (ADS)

Titov, Vasily V.; Bernard, Eddie N.; Weinstein, Stuart A.; Kanoglu, Utku; Synolakis, Costas E.

2010-05-01

Almost five years after the 26 December 2004 Indian Ocean tragedy, tsunami warnings are finally benefiting from decades of research toward effective model-based forecasts. Since the 2004 tsunami, two seminal advances have been (i) deep-ocean tsunami measurements with tsunameters and (ii) their use in accurately forecasting tsunamis after the tsunami has been generated. Using direct measurements of deep-ocean tsunami heights, assimilated into numerical models for specific locations, greatly improves the real-time forecast accuracy over earthquake-derived magnitude estimates of tsunami impact. Since 2003, this method has been used to forecast tsunamis at specific harbors for different events in the Pacific and Indian Oceans. Recent tsunamis illustrated how this technology is being adopted in global tsunami warning operations. The U.S. forecasting system was used by both research and operations to evaluate the tsunami hazard. Tests demonstrated the effectiveness of operational tsunami forecasting using real-time deep-ocean data assimilated into forecast models. Several examples also showed potential of distributed forecast tools. With IOC and USAID funding, NOAA researchers at PMEL developed the Community Model Interface for Tsunami (ComMIT) tool and distributed it through extensive capacity-building sessions in the Indian Ocean. Over hundred scientists have been trained in tsunami inundation mapping, leading to the first generation of inundation models for many Indian Ocean shorelines. These same inundation models can also be used for real-time tsunami forecasts as was demonstrated during several events. Contact Information Vasily V. Titov, Seattle, Washington, USA, 98115

Sandy signs of a tsunami's onshore depth and speed

USGS Publications Warehouse

Huntington, K.; Bourgeois, J.; Gelfenbaum, G.; Lynett, P.; Jaffe, B.; Yeh, H.; Weiss, R.

2007-01-01

Tsunamis rank among the most devastating and unpredictable natural hazards to affect coastal areas. Just 3 years ago, in December 2004, the Indian Ocean tsunami caused more than 225,000 deaths. Like many extreme events, however, destructive tsunamis strike rarely enough that written records span too little time to quantify tsunami hazard and risk. Tsunami deposits preserved in the geologic record have been used to extend the record of tsunami occurrence but not the magnitude of past events. To quantify tsunami hazard further, we asked the following question: Can ancient deposits also provide guidance on the expectable water depths and speeds for future tsunamis?

Community Destruction and Traumatic Stress in Post-Tsunami Indonesia

ERIC Educational Resources Information Center

Frankenberg, Elizabeth; Nobles, Jenna; Sumantri, Cecep

2012-01-01

How are individuals affected when the communities they live in change for the worse? This question is central to understanding neighborhood effects, but few study designs generate estimates that can be interpreted causally. We address issues of inference through a natural experiment, examining post-traumatic stress at multiple time points in a…

Machine-learning techniques for geochemical discrimination of 2011 Tohoku tsunami deposits

PubMed Central

Kuwatani, Tatsu; Nagata, Kenji; Okada, Masato; Watanabe, Takahiro; Ogawa, Yasumasa; Komai, Takeshi; Tsuchiya, Noriyoshi

2014-01-01

Geochemical discrimination has recently been recognised as a potentially useful proxy for identifying tsunami deposits in addition to classical proxies such as sedimentological and micropalaeontological evidence. However, difficulties remain because it is unclear which elements best discriminate between tsunami and non-tsunami deposits. Herein, we propose a mathematical methodology for the geochemical discrimination of tsunami deposits using machine-learning techniques. The proposed method can determine the appropriate combinations of elements and the precise discrimination plane that best discerns tsunami deposits from non-tsunami deposits in high-dimensional compositional space through the use of data sets of bulk composition that have been categorised as tsunami or non-tsunami sediments. We applied this method to the 2011 Tohoku tsunami and to background marine sedimentary rocks. After an exhaustive search of all 262,144 (= 218) combinations of the 18 analysed elements, we observed several tens of combinations with discrimination rates higher than 99.0%. The analytical results show that elements such as Ca and several heavy-metal elements are important for discriminating tsunami deposits from marine sedimentary rocks. These elements are considered to reflect the formation mechanism and origin of the tsunami deposits. The proposed methodology has the potential to aid in the identification of past tsunamis by using other tsunami proxies. PMID:25399750

Tsunami Casualty Model

NASA Astrophysics Data System (ADS)

Yeh, H.

2007-12-01

More than 4500 deaths by tsunamis were recorded in the decade of 1990. For example, the 1992 Flores Tsunami in Indonesia took away at least 1712 lives, and more than 2182 people were victimized by the 1998 Papua New Guinea Tsunami. Such staggering death toll has been totally overshadowed by the 2004 Indian Ocean Tsunami that claimed more than 220,000 lives. Unlike hurricanes that are often evaluated by economic losses, death count is the primary measure for tsunami hazard. It is partly because tsunamis kill more people owing to its short lead- time for warning. Although exact death tallies are not available for most of the tsunami events, there exist gender and age discriminations in tsunami casualties. Significant gender difference in the victims of the 2004 Indian Ocean Tsunami was attributed to women's social norms and role behavior, as well as cultural bias toward women's inability to swim. Here we develop a rational casualty model based on humans' limit to withstand the tsunami flows. The application to simple tsunami runup cases demonstrates that biological and physiological disadvantages also make a significant difference in casualty rate. It further demonstrates that the gender and age discriminations in casualties become most pronounced when tsunami is marginally strong and the difference tends to diminish as tsunami strength increases.

One year after the 1 April 2014 Iquique tsunami field survey along the coasts of Chile and Peru

NASA Astrophysics Data System (ADS)

Lagos, Marcelo; Fritz, Hermann M.

2015-04-01

One year ago on the evening of 1 April, 2014 a magnitude Mw 8.2 earthquake occurred off the coast of northern Chile off the coast of Pisagua within a region of historic quiescence termed the northern Chile seismic gap. The ensuing tsunami inundation caused mostly minor damage centered in Iquique and neighbouring stretches of coastline. Fortunately, ancestral knowledge from the past 1868 and 1877 tsunamis in the region along with the recent 2010 Maule tsunami, as well as tsunami education and evacuation exercises prompted most coastal residents to spontaneously evacuate to high ground after the earthquake. There were no tsunami victims; while a handful of fatalities were associated to earthquake induced building collapses and the physical stress of tsunami evacuation. The Arica native local scientist deployed overnight and started the tsunami survey in Iquique on the day after the earthquake. The international scientist joined the local effort from April 6 to 11, 2014. The international tsunami survey team (ITST) interviewed numerous eyewitnesses and documented flow depths, runup heights, inundation distances, sediment deposition, damage patterns, performance of the navigation infrastructure and impact on the natural environment. The ITST covered a 700 km stretch of coastline from the Mejillones Peninsula (23.5° S) north of Antofagasta in Chile up to Vila Vila (18.1° S) in southern Peru. We surveyed 30 locations with differential GPS and laser range finders. The tsunami impact peaked at Caleta Camarones exceeding 5 m in tsunami runup height. A significant variation in tsunami impact was observed along the coastlines of Chile and Peru both at local and regional scales. The tsunami occurred in the evening hours limiting the availability of eyewitness video footages. Observations from the 2014 Chile tsunami are compared against the 1868, 1877 and 2010 Chile tsunamis. Comparing to other similar magnitude events such as the 2007 Pisco tsunami in Peru the 1 April 2014 tsunami could have been significantly larger. The absence of a massive tsunami may mislead residents to believe another similarly minor tsunami may be generated after a potential future earthquake of similar magnitude. This April fool's day event poses significant challenges to community-based education raising tsunami awareness. The team educated residents about tsunami hazards since awareness programs are essential to save lives in locales at risk from near-field tsunamis.

In Search of the Largest Possible Tsunami: An Example Following the 2011 Japan Tsunami

NASA Astrophysics Data System (ADS)

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 likely limit the maximum tsunami runup at a particular site. However, historic and prehistoric data alone cannot determine the upper bound on tsunami runup. Because of problems endemic to sampling Pareto distributions of tsunamis and their sources, we recommend that tsunami hazard assessment be based on a specific design probability of exceedance following a pure Pareto distribution, rather than attempting to determine the worst-case scenario.

Vulnerability assessment of a port and harbor community to earthquake and tsunami hazards: Integrating technical expert and stakeholder input

USGS Publications Warehouse

Wood, Nathan J.; Good, James W.; Goodwin, Robert F.

2002-01-01

Research suggests that the Pacific Northwest could experience catastrophic earthquakes and tsunamis in the near future, posing a significant threat to the numerous ports and harbors along the coast. A collaborative, multiagency initiative is underway to increase the resiliency of Pacific Northwest ports and harbors to these hazards, involving Oregon Sea Grant, Washington Sea Grant, the National Oceanic and Atmospheric Administration Coastal Services Center, and the U.S. Geological Survey Center for Science Policy. One element of this research, planning, and outreach initiative is a natural hazard mitigation and emergency preparedness planning process that combines technical expertise with local stakeholder values and perceptions. This paper summarizes and examines one component of the process, the vulnerability assessment methodology, used in the pilot port and harbor community of Yaquina River, Oregon, as a case study of assessing vulnerability at the local level. In this community, stakeholders were most concerned with potential life loss and other nonstructural vulnerability issues, such as inadequate hazard awareness, communication, and response logistics, rather than structural issues, such as damage to specific buildings or infrastructure.

Natural Hazards, Second Edition

NASA Astrophysics Data System (ADS)

Rouhban, Badaoui

Natural disaster loss is on the rise, and the vulnerability of the human and physical environment to the violent forces of nature is increasing. In many parts of the world, disasters caused by natural hazards such as earthquakes, floods, landslides, drought, wildfires, intense windstorms, tsunami, and volcanic eruptions have caused the loss of human lives, injury, homelessness, and the destruction of economic and social infrastructure. Over the last few years, there has been an increase in the occurrence, severity, and intensity of disasters, culminating with the devastating tsunami of 26 December 2004 in South East Asia.Natural hazards are often unexpected or uncontrollable natural events of varying magnitude. Understanding their mechanisms and assessing their distribution in time and space are necessary for refining risk mitigation measures. This second edition of Natural Hazards, (following a first edition published in 1991 by Cambridge University Press), written by Edward Bryant, associate dean of science at Wollongong University, Australia, grapples with this crucial issue, aspects of hazard prediction, and other issues. The book presents a comprehensive analysis of different categories of hazards of climatic and geological origin.

Determining critical infrastructure for ocean research and societal needs in 2030

NASA Astrophysics Data System (ADS)

Glickson, Deborah; Barron, Eric; Fine, Rana

2011-06-01

The United States has jurisdiction over 3.4 million square miles of ocean—an expanse greater than the land area of all 50 states combined. This vast marine area offers researchers opportunities to investigate the ocean's role in an integrated Earth system but also presents challenges to society, including damaging tsunamis and hurricanes, industrial accidents, and outbreaks of waterborne diseases. The 2010 Gulf of Mexico Deepwater Horizon oil spill and 2011 Japanese earthquake and tsunami are vivid reminders that a broad range of infrastructure is needed to advance scientists' still incomplete understanding of the ocean. The National Research Council's (NRC) Ocean Studies Board was asked by the National Science and Technology Council's Subcommittee on Ocean Science and Technology, comprising 25 U.S. government agencies, to examine infrastructure needs for ocean research in the year 2030. This request reflects concern, among a myriad of marine issues, over the present state of aging and obsolete infrastructure, insufficient capacity, growing technological gaps, and declining national leadership in marine technological development; these issues were brought to the nation's attention in 2004 by the U.S. Commission on Ocean Policy.

Paleo-tsunami history along the northern Japan Trench: evidence from Noda Village, northern Sanriku coast, Japan

NASA Astrophysics Data System (ADS)

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.

Response to the 2011 Great East Japan Earthquake and Tsunami disaster.

PubMed

Koshimura, Shunichi; Shuto, Nobuo

2015-10-28

We revisited the lessons of the 2011 Great East Japan Earthquake Tsunami disaster specifically on the response and impact, and discussed the paradigm shift of Japan's tsunami disaster management policies and the perspectives for reconstruction. Revisiting the modern histories of Tohoku tsunami disasters and pre-2011 tsunami countermeasures, we clarified how Japan's coastal communities have prepared for tsunamis. The discussion mainly focuses on structural measures such as seawalls and breakwaters and non-structural measures of hazard map and evacuation. The responses to the 2011 event are discussed specifically on the tsunami warning system and efforts to identify the tsunami impacts. The nation-wide post-tsunami survey results shed light on the mechanisms of structural destruction, tsunami loads and structural vulnerability to inform structural rehabilitation measures and land-use planning. Remarkable paradigm shifts in designing coastal protection and disaster mitigation measures were introduced, leading with a new concept of potential tsunami levels: Prevention (Level 1) and Mitigation (Level 2) levels according to the level of 'protection'. The seawall is designed with reference to Level 1 tsunami scenario, while comprehensive disaster management measures should refer to Level 2 tsunami for protection of human lives and reducing potential losses and damage. Throughout the case study in Sendai city, the proposed reconstruction plan was evaluated from the tsunami engineering point of view to discuss how the post 2011 paradigm was implemented in coastal communities for future disaster mitigation. The analysis revealed that Sendai city's multiple protection measures for Level 2 tsunami will contribute to a substantial reduction of the tsunami inundation zone and potential losses, combined with an effective tsunami evacuation plan. © 2015 The Author(s).

Earthquake and Tsunami booklet based on two Indonesia earthquakes

NASA Astrophysics Data System (ADS)

Hayashi, Y.; Aci, M.

2014-12-01

Many destructive earthquakes occurred during the last decade in Indonesia. These experiences are very important precepts for the world people who live in earthquake and tsunami countries. We are collecting the testimonies of tsunami survivors to clarify successful evacuation process and to make clear the characteristic physical behaviors of tsunami near coast. We research 2 tsunami events, 2004 Indian Ocean tsunami and 2010 Mentawai slow earthquake tsunami. Many video and photographs were taken by people at some places in 2004 Indian ocean tsunami disaster; nevertheless these were few restricted points. We didn't know the tsunami behavior in another place. In this study, we tried to collect extensive information about tsunami behavior not only in many places but also wide time range after the strong shake. In Mentawai case, the earthquake occurred in night, so there are no impressive photos. To collect detail information about evacuation process from tsunamis, we contrived the interview method. This method contains making pictures of tsunami experience from the scene of victims' stories. In 2004 Aceh case, all survivors didn't know tsunami phenomena. Because there were no big earthquakes with tsunami for one hundred years in Sumatra region, public people had no knowledge about tsunami. This situation was highly improved in 2010 Mentawai case. TV programs and NGO or governmental public education programs about tsunami evacuation are widespread in Indonesia. Many people know about fundamental knowledge of earthquake and tsunami disasters. We made drill book based on victim's stories and painted impressive scene of 2 events. We used the drill book in disaster education event in school committee of west Java. About 80 % students and teachers evaluated that the contents of the drill book are useful for correct understanding.

Integrated Historical Tsunami Event and Deposit Database

NASA Astrophysics Data System (ADS)

Dunbar, P. K.; McCullough, H. L.

2010-12-01

The National Geophysical Data Center (NGDC) provides integrated access to historical tsunami event, deposit, and proxy data. The NGDC tsunami archive initially listed tsunami sources and locations with observed tsunami effects. Tsunami frequency and intensity are important for understanding tsunami hazards. Unfortunately, tsunami recurrence intervals often exceed the historic record. As a result, NGDC expanded the archive to include the Global Tsunami Deposits Database (GTD_DB). Tsunami deposits are the physical evidence left behind when a tsunami impacts a shoreline or affects submarine sediments. Proxies include co-seismic subsidence, turbidite deposits, changes in biota following an influx of marine water in a freshwater environment, etc. By adding past tsunami data inferred from the geologic record, the GTD_DB extends the record of tsunamis backward in time. Although the best methods for identifying tsunami deposits and proxies in the geologic record remain under discussion, developing an overall picture of where tsunamis have affected coasts, calculating recurrence intervals, and approximating runup height and inundation distance provides a better estimate of a region’s true tsunami hazard. Tsunami deposit and proxy descriptions in the GTD_DB were compiled from published data found in journal articles, conference proceedings, theses, books, conference abstracts, posters, web sites, etc. The database now includes over 1,200 descriptions compiled from over 1,100 citations. Each record in the GTD_DB is linked to its bibliographic citation where more information on the deposit can be found. The GTD_DB includes data for over 50 variables such as: event description (e.g., 2010 Chile Tsunami), geologic time period, year, deposit location name, latitude, longitude, country, associated body of water, setting during the event (e.g., beach, lake, river, deep sea), upper and lower contacts, underlying and overlying material, etc. If known, the tsunami source mechanism (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).

Towards a certification process for tsunami early warning systems

NASA Astrophysics Data System (ADS)

Löwe, Peter; Wächter, Jochen; Hammitzsch, Martin

2013-04-01

The natural disaster of the Boxing Day Tsunami of 2004 was followed by an information catastrophe. Crucial early warning information could not be delivered to the communities under imminent threat, resulting in over 240,000 casualties in 14 countries. This tragedy sparked the development of a new generation of integrated modular Tsunami Early Warning Systems (TEWS). While significant advances were accomplished in the past years, recent events, like the Chile 2010 and the Tohoku 2011 tsunami demonstrate that the key technical challenge for Tsunami Early Warning research on the supranational scale still lies in the timely issuing of status information and reliable early warning messages in a proven workflow. A second challenge stems from the main objective of the Intergovernmental Oceanographic Commission of UNESCO (IOC) Tsunami Programme, the integration of national TEWS towards ocean-wide networks: Each of the increasing number of integrated Tsunami Early Warning Centres has to cope with the continuing evolution of sensors, hardware and software while having to maintain reliable inter-center information exchange services. To avoid future information catastrophes, the performance of all components, ranging from individual sensors, to Warning Centers within their particular end-to-end Warning System Environments, and up to federated Systems of Tsunami Warning Systems has to be regularly validated against defined criteria. Since 2004, GFZ German Research Centre for Geosciences (GFZ) has built up expertise in the field of TEWS. Within GFZ, the Centre for GeoInformation Technology (CeGIT) has focused its work on the geoinformatics aspects of TEWS in two projects already, being the German Indonesian Tsunami Early Warning System (GITEWS) and the Distant Early Warning System (DEWS). This activity is continued in the TRIDEC project (Collaborative, Complex, and Critical Decision Processes in Evolving Crises) funded under the European Union's seventh Framework Programme (FP7). TRIDEC focuses on real-time intelligent information management in Earth management and its long-term application: The technical development is based on mature system architecture models and industry standards. The use of standards already applies to the operation of individual TRIDEC reference installations and their interlinking into an integrated service infrastructure for supranational warning services. This is a first step towards best practices and service lifecycles for Early Warning Centre IT service management, including Service Level Agreements (SLA) and Service Certification. While on a global scale the integration of TEWS progresses towards Systems of Systems (SoS), there is still an absence of accredited and reliable certifications for national TEWS or regional Tsunami Early Warning Systems of Systems (TEWSoS). Concepts for TEWS operations have already been published under the guidance of the IOC, and can now be complemented by the recent research advances concerning SoS architecture. Combined with feedback from the real world, such as the NEAMwave 2012 Tsunami exercise in the Mediterranean, this can serve as a starting point to formulate initial requirements for TEWS and TEWSoS certification: Certification activities will cover the establishment of new TEWS and TEWSoS, and also both maintenance and enhancement of existing TEWS/TEWSoS. While the IOC is expected to take a central role in the development of the certification strategy, it remains to be defined which bodies will actually conduct the certification process. Certification requirements and results are likely to become a valuable information source for various target groups, ranging from national policy decision makers, government agency planners, national and local government preparedness officials, TWC staff members, Disaster Responders, the media and the insurance industry.

The Puerto Rico Component of the National Tsunami Hazard and Mitigation Program (PR-NTHMP)

NASA Astrophysics Data System (ADS)

Vanacore, E. A.; Huerfano Moreno, V. A.; Lopez, A. M.

2015-12-01

The Caribbean region has a documented history of damaging tsunamis that have affected coastal areas. Of particular interest is the Puerto Rico - Virgin Islands (PRVI) region, where the proximity of the coast to prominent tectonic faults would result in near-field tsunamis. Tsunami hazard assessment, detection capabilities, warning, education and outreach efforts are common tools intended to reduce loss of life and property. It is for these reasons that the PRSN is participating in an effort with local and federal agencies to develop tsunami hazard risk reduction strategies under the NTHMP. This grant supports the TsunamiReady program, which is the base of the tsunami preparedness and mitigation in PR. In order to recognize threatened communities in PR as TsunamiReady by the US NWS, the PR Component of the NTHMP have identified and modeled sources for local, regional and tele-tsunamis and the results of simulations have been used to develop tsunami response plans. The main goal of the PR-NTHMP is to strengthen resilient coastal communities that are prepared for tsunami hazards, and recognize PR as TsunamiReady. Evacuation maps were generated in three phases: First, hypothetical tsunami scenarios of potential underwater earthquakes were developed, and these scenarios were then modeled through during the second phase. The third phase consisted in determining the worst-case scenario based on the Maximum of Maximums (MOM). Inundation and evacuation zones were drawn on GIS referenced maps and aerial photographs. These products are being used by emergency managers to educate the public and develop mitigation strategies. Maps and related evacuation products, like evacuation times, can be accessed online via the PR Tsunami Decision Support Tool. Based on these evacuation maps, tsunami signs were installed, vulnerability profiles were created, communication systems to receive and disseminate tsunami messages were installed in each TWFP, and tsunami response plans were approved. Also, the existing tsunami protocol and criteria in the PR/VI was updated. This paper describes the PR-NTHMP recent outcomes, including the real time monitoring as well as the protocols used to broadcast tsunami messages. The paper highlights tsunami hazards assessment, detection, warning, education and outreach efforts in Puerto Rico.

Possible worst-case tsunami scenarios around the Marmara Sea from combined earthquake and landslide sources

NASA Astrophysics Data System (ADS)

Latcharote, Panon; Suppasri, Anawat; Imamura, Fumihiko; Aytore, Betul; Yalciner, Ahmet Cevdet

2016-12-01

This study evaluates tsunami hazards in the Marmara Sea from possible worst-case tsunami scenarios that are from submarine earthquakes and landslides. In terms of fault-generated tsunamis, seismic ruptures can propagate along the North Anatolian Fault (NAF), which has produced historical tsunamis in the Marmara Sea. Based on the past studies, which consider fault-generated tsunamis and landslide-generated tsunamis individually, future scenarios are expected to generate tsunamis, and submarine landslides could be triggered by seismic motion. In addition to these past studies, numerical modeling has been applied to tsunami generation and propagation from combined earthquake and landslide sources. In this study, tsunami hazards are evaluated from both individual and combined cases of submarine earthquakes and landslides through numerical tsunami simulations with a grid size of 90 m for bathymetry and topography data for the entire Marmara Sea region and validated with historical observations from the 1509 and 1894 earthquakes. This study implements TUNAMI model with a two-layer model to conduct numerical tsunami simulations, and the numerical results show that the maximum tsunami height could reach 4.0 m along Istanbul shores for a full submarine rupture of the NAF, with a fault slip of 5.0 m in the eastern and western basins of the Marmara Sea. The maximum tsunami height for landslide-generated tsunamis from small, medium, and large of initial landslide volumes (0.15, 0.6, and 1.5 km3, respectively) could reach 3.5, 6.0, and 8.0 m, respectively, along Istanbul shores. Possible tsunamis from submarine landslides could be significantly higher than those from earthquakes, depending on the landslide volume significantly. These combined earthquake and landslide sources only result in higher tsunami amplitudes for small volumes significantly because of amplification within the same tsunami amplitude scale (3.0-4.0 m). Waveforms from all the coasts around the Marmara Sea indicate that other residential areas might have had a high risk of tsunami hazards from submarine landslides, which can generate higher tsunami amplitudes and shorter arrival times, compared to Istanbul.

Aspects of Global Health Issues: Diseases, Natural Disasters, and Pharmaceutical Corporations and Medical Research.

PubMed

Brown, Geraldine

2016-01-01

Global health issues are concerns of all public health officials throughout the world. This entails reviewing aspects such as the impact of poverty and the lack of access to quality health care, ignored global killers such as Diseases (Infectious diseases-Malaria, HIV/AIDS), Natural Disasters (Earthquakes, Tsunamis, Floods, and Armed Conflict), Health in the Media, and the Involvement of Pharmaceutical Corporations and Medical Research. These issues are challenges to many needless deaths. Global initiatives are not advancing as they should, such as access to drugs and medications, which some are political.

A simple model for calculating tsunami flow speed from tsunami deposits

USGS Publications Warehouse

Jaffe, B.E.; Gelfenbuam, G.

2007-01-01

This paper presents a simple model for tsunami sedimentation that can be applied to calculate tsunami flow speed from the thickness and grain size of a tsunami deposit (the inverse problem). For sandy tsunami deposits where grain size and thickness vary gradually in the direction of transport, tsunami sediment transport is modeled as a steady, spatially uniform process. The amount of sediment in suspension is assumed to be in equilibrium with the steady portion of the long period, slowing varying uprush portion of the tsunami. Spatial flow deceleration is assumed to be small and not to contribute significantly to the tsunami deposit. Tsunami deposits are formed from sediment settling from the water column when flow speeds on land go to zero everywhere at the time of maximum tsunami inundation. There is little erosion of the deposit by return flow because it is a slow flow and is concentrated in topographic lows. Variations in grain size of the deposit are found to have more effect on calculated tsunami flow speed than deposit thickness. The model is tested using field data collected at Arop, Papua New Guinea soon after the 1998 tsunami. Speed estimates of 14??m/s at 200??m inland from the shoreline compare favorably with those from a 1-D inundation model and from application of Bernoulli's principle to water levels on buildings left standing after the tsunami. As evidence that the model is applicable to some sandy tsunami deposits, the model reproduces the observed normal grading and vertical variation in sorting and skewness of a deposit formed by the 1998 tsunami.

The U.S. National Tsunami Hazard Mitigation Program: Successes in Tsunami Preparedness

NASA Astrophysics Data System (ADS)

Whitmore, P.; Wilson, R. I.

2012-12-01

Formed in 1995 by Congressional Action, the National Tsunami Hazards Mitigation Program (NTHMP) provides the framework for tsunami preparedness activities in the United States. The Program consists of the 28 U.S. coastal states, territories, and commonwealths (STCs), as well as three Federal agencies: the National Oceanic and Atmospheric Administration (NOAA), the Federal Emergency Management Agency (FEMA), and the United States Geological Survey (USGS). Since its inception, the NTHMP has advanced tsunami preparedness in the United States through accomplishments in many areas of tsunami preparedness: - Coordination and funding of tsunami hazard analysis and preparedness activities in STCs; - Development and execution of a coordinated plan to address education and outreach activities (materials, signage, and guides) within its membership; - Lead the effort to assist communities in meeting National Weather Service (NWS) TsunamiReady guidelines through development of evacuation maps and other planning activities; - Determination of tsunami hazard zones in most highly threatened coastal communities throughout the country by detailed tsunami inundation studies; - Development of a benchmarking procedure for numerical tsunami models to ensure models used in the inundation studies meet consistent, NOAA standards; - Creation of a national tsunami exercise framework to test tsunami warning system response; - Funding community tsunami warning dissemination and reception systems such as sirens and NOAA Weather Radios; and, - Providing guidance to NOAA's Tsunami Warning Centers regarding warning dissemination and content. NTHMP activities have advanced the state of preparedness of United States coastal communities, and have helped save lives and property during recent tsunamis. Program successes as well as future plans, including maritime preparedness, are discussed.

Historic Tsunami in the Indian Ocean

NASA Astrophysics Data System (ADS)

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.

The SAFRR Tsunami Scenario: Improving Resilience for California from a Plausible M9 Earthquake near the Alaska Peninsula

NASA Astrophysics Data System (ADS)

Ross, S.; Jones, L.; Wilson, R. I.; Bahng, B.; Barberopoulou, A.; Borrero, J. C.; Brosnan, D.; Bwarie, J.; Geist, E. L.; Johnson, L.; Kirby, S. H.; Knight, W.; Long, K.; Lynett, P. J.; Miller, K.; Mortensen, C. E.; Nicolsky, D.; Oglesby, D. D.; Perry, S. C.; Plumlee, G. S.; Porter, K. A.; Real, C. R.; Ryan, K. J.; Suleimani, E.; Thio, H. K.; Titov, V.; Wein, A. M.; Whitmore, P.; Wood, N. J.

2013-12-01

The SAFRR Tsunami Scenario models a hypothetical but plausible tsunami, created by an Mw9.1 earthquake occurring offshore from the Alaskan peninsula, and its impacts on the California coast. We present the likely inundation areas, current velocities in key ports and harbors, physical damage and repair costs, economic consequences, environmental impacts, social vulnerability, emergency management, and policy implications for California associated with the tsunami scenario. The intended users are those who must make mitigation decisions before and rapid decisions during future tsunamis. Around a half million people would be present in the scenario's inundation area in residences, businesses, public venues, parks and beaches. Evacuation would likely be ordered for the State of California's maximum mapped tsunami inundation zone, evacuating an additional quarter million people from residences and businesses. Some island and peninsula communities would face particular evacuation challenges because of limited access options and short warning time, caused by the distance between Alaska and California. Evacuations may also be a challenge for certain dependent-care populations. One third of the boats in California's marinas could be damaged or sunk, costing at least 700 million in repairs to boats and docks, and potentially much more to address serious issues due to sediment transport and environmental contamination. Fires would likely start at many sites where fuel and petrochemicals are stored in ports and marinas. Tsunami surges and bores may travel several miles inland up coastal rivers. Debris clean-up and recovery of inundated and damaged areas will take days, months, or years depending on the severity of impacts and the available resources for recovery. The Ports of Los Angeles and Long Beach (POLA/LB) would be shut down for a miniμm of two days due to strong currents. Inundation of dry land in the ports would result in 100 million damages to cargo and additional downtime. The direct exposure of port trade value totals over 1.2 billion, while associated business interruption losses in the California economy could more than triple that value. Other estimated damages include 1.8 billion of property damage and 85 million for highway and railroad repairs. In total, we have estimated repair and replacement costs of almost 3 billion to California marinas, coastal properties and the POLA/LB. These damages could cause $6 billion of business interruption losses in the California economy, but that could be reduced by 80-90% with the implementation of business continuity or resilience strategies. This scenario provides the basis for improving preparedness, mitigation, and continuity planning for tsunamis, which can reduce damage and economic impacts and enhance recovery efforts. Two positive outcomes have already resulted from the SAFRR Tsunami Scenario. Emergency managers in areas where the scenario inundation exceeds the State's maximum inundation zone have been notified and evacuation plans have been updated appropriately. The State has also worked with NOAA's West Coast and Alaska Tsunami Warning Center to modify future message protocols to facilitate effective evacuations in California. While our specific results pertain to California, the lessons learned and our scenario approach can be applied to other regions.

Historical extreme wave and landslide deposits on the Shirasuka coastal lowlands, Shizuoka Prefecture, Japan

NASA Astrophysics Data System (ADS)

Garrett, Ed; Riedesel, Svenja; Fujiwara, Osamu; Walstra, Jan; Deforce, Koen; Yokoyama, Yusuke; Schmidt, Sabine; Brill, Dominik; Roberts, Helen; Duller, Geoff; Brückner, Hulmut; De Batist, Marc; Heyvaert, Vanessa

2017-04-01

Future megathrust earthquakes and consequential tsunamis pose exceptional hazards to densely populated and highly industrialised coastlines facing the Nankai-Suruga Trough, south central Japan. Geological investigations of coastal sedimentary sequences play a key role in understanding megathrust behaviour and developing seismic and tsunami hazard assessments. In this study, we revisit a previously published palaeoseismic site at Shirasuka, located on the Enshu-nada coastline of Shizuoka Prefecture, seeking both to provide further information on past earthquakes and tsunamis and to explore the prospects and limitations of geological data with respect to assessing seismic and tsunami hazards. At Shirasuka, six closely-spaced vibrocores reveal four sand layers interbedded with organic muds. Photographs, X-ray CT scans and grain size analysis reveal a variety of sedimentary structures within these layers, including abrupt contacts, massive sands, rip-up clasts, internal mud drapes and cross bedding. Microfossil assemblages (diatoms, pollen, non-pollen palynomorphs) and optically stimulated luminescence overdispersion values of single grain feldspars highlight varying sediment sources and transport mechanisms. We suggest that the uppermost sand layer records a landslide from the landward margin of the site, while the remaining three sand layers reflect at least four extreme wave events, some of which are overprinted. We refine the published chronology using AMS radiocarbon, radionuclide and infrared stimulated luminescence approaches. Our Bayesian age models suggest that the oldest two sand layers relate to historically documented tsunamis in AD 1361 and 1498. The second youngest sand layer provides ages consistent with tsunamis in AD 1605 and 1707 and potentially also storm surges in 1680 and/or 1699. The modelled age of the landslide sand layer is consistent with the AD 1944 earthquake. The presence of a fresh scarp in US military aerial photographs from 1947 and revegetation by 1959 is also consistent with possible coseismic triggering of this landslide. Difficulties in correlating sand layers between cores, the identification of overprinting of evidence and the lack of prehistoric deposits exemplify ongoing issues in the search for palaeotsunami deposits along the Nankai-Suruga Trough. The identification of a subaerial mass movement deposit as possible evidence for coseismic shaking provides a potentially complementary palaeoseismic approach and an area for further investigation.

Tsunami vulnerability assessment mapping for the west coast of Peninsular Malaysia using a geographical information system (GIS)

NASA Astrophysics Data System (ADS)

Najihah, R.; Effendi, D. M.; Hairunnisa, M. A.; Masiri, K.

2014-02-01

The catastrophic Indian Ocean tsunami of 26 December 2004 raised a number of questions for scientist and politicians on how to deal with the tsunami risk and assessment in coastal regions. This paper discusses the challenges in tsunami vulnerability assessment and presents the result of tsunami disaster mapping and vulnerability assessment study for West Coast of Peninsular Malaysia. The spatial analysis was carried out using Geographical Information System (GIS) technology to demarcate spatially the tsunami affected village's boundary and suitable disaster management program can be quickly and easily developed. In combination with other thematic maps such as road maps, rail maps, school maps, and topographic map sheets it was possible to plan the accessibility and shelter to the affected people. The tsunami vulnerability map was used to identify the vulnerability of villages/village population to tsunami. In the tsunami vulnerability map, the intensity of the tsunami was classified as hazard zones based on the inundation level in meter (contour). The approach produced a tsunami vulnerability assessment map consists of considering scenarios of plausible extreme, tsunami-generating events, computing the tsunami inundation levels caused by different events and scenarios and estimating the possible range of casualties for computing inundation levels. The study provides an interactive means to identify the tsunami affected areas after the disaster and mapping the tsunami vulnerable village before for planning purpose were the essential exercises for managing future disasters.

Japanese Experience with Long-term Recovery from the 2011 Tohoku　Earthquake and Tsunami Disaster

NASA Astrophysics Data System (ADS)

Hayashi, H.

2015-12-01

On March 11, 2011, a huge tsunami disaster hit Pacific coast of Tohoku region due to a magnitude of 9.0 earthquake, and killed almost 20,000 people. It was also the beginning of long-term recovery to prepare for next tsunami attack in the future. In this presentation, I would like to review the recovery process from the following five elements: quantification of tsunami hazards, public education, evacuation model, land-use planning, and real-time tsunami warning. It should be noted that there are lessons from the 2011 event at two different levels: national level and prefecture levels. In relation to the quantification of tsunami hazard and real-time tsunami warning, it followed a big change in tsunami policy at national level such as setting up two levels of tsunami scenarios for tsunami preparedness and mitigation: Level 1 tsunami (L1) and Level 2 tsunami (L2). L1 is the tsunami risk with 50 year return period, and L2 is the one with 1,000 year return period. As for public education, evacuation model, and land-use planning, There existed a big difference for what happened in the northern half of the coast and the southern half. Northern half of the coast belongs to Iwate Prefecture whose geography is rias coast. People in the Rias coast of Iwate Prefecture has been hit many times by tsunami on the average of about 50 years. With these many experiences, they succeeded in reducing the number of mortality down to 4,000 in comparison with 20,000 at the 1886 tsunami disaster. Most of the Southern half belongs to Miyagi Prefecture whose geography is coastal plain. People in the coastal plain in Miyagi Prefecture has little experience with tsunami disaster and end up with 14,000 deaths due to tsunami attack. The differences in the past tsunami experiences in these two prefectures resulted in big differences in public education, evacuation model, and land-use planning.

Development of Real-time Tsunami Inundation Forecast Using Ocean Bottom Tsunami Networks along the Japan Trench

NASA Astrophysics Data System (ADS)

Aoi, S.; Yamamoto, N.; Suzuki, W.; Hirata, K.; Nakamura, H.; Kunugi, T.; Kubo, T.; Maeda, T.

2015-12-01

In the 2011 Tohoku earthquake, in which huge tsunami claimed a great deal of lives, the initial tsunami forecast based on hypocenter information estimated using seismic data on land were greatly underestimated. From this lesson, NIED is now constructing S-net (Seafloor Observation Network for Earthquakes and Tsunamis along the Japan Trench) which consists of 150 ocean bottom observatories with seismometers and pressure gauges (tsunamimeters) linked by fiber optic cables. To take full advantage of S-net, we develop a new methodology of real-time tsunami inundation forecast using ocean bottom observation data and construct a prototype system that implements the developed forecasting method for the Pacific coast of Chiba prefecture (Sotobo area). We employ a database-based approach because inundation is a strongly non-linear phenomenon and its calculation costs are rather heavy. We prepare tsunami scenario bank in advance, by constructing the possible tsunami sources, and calculating the tsunami waveforms at S-net stations, coastal tsunami heights and tsunami inundation on land. To calculate the inundation for target Sotobo area, we construct the 10-m-mesh precise elevation model with coastal structures. Based on the sensitivities analyses, we construct the tsunami scenario bank that efficiently covers possible tsunami scenarios affecting the Sotobo area. A real-time forecast is carried out by selecting several possible scenarios which can well explain real-time tsunami data observed at S-net from tsunami scenario bank. An advantage of our method is that tsunami inundations are estimated directly from the actual tsunami data without any source information, which may have large estimation errors. In addition to the forecast system, we develop Web services, APIs, and smartphone applications and brush them up through social experiments to provide the real-time tsunami observation and forecast information in easy way to understand toward urging people to evacuate.

The 2011 Tohoku Tsunami on the Coast of Mexico: A Case Study

NASA Astrophysics Data System (ADS)

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 <1.7 cph (periods >35 min). The "red colour" (i.e., the prevalence of low-frequency waves) in the 2011 Tohoku, as well as in the 2010 Chile tsunamis, is explained by the large extension of the source areas. In contrast, the 2014 and 2015 Chilean earthquakes had much smaller source areas and, consequently, induced "bluish" (high-frequency) tsunamis.

The tsunami phenomenon

NASA Astrophysics Data System (ADS)

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 Boussinesq approximation-a simplification of the three-dimensional Navier-Stokes equations-is presented as a basic theory behind numerical tsunami models, which adequately reflects the non-linear, dispersive wave behaviour of tsunamis. The fully non-linear Boussinesq equations allow the simulation of tsunamis e.g. in the form of N-waves. Based on the various subtopics presented, recommendations for future multidisciplinary tsunami research are made. It is especially discussed how the combination of sedimentary and geomorphological tsunami field traces and numerical modelling techniques can contribute to derive locally relevant tsunami sources and to improve the assessment of tsunami hazards considering the individual pre-/history and physiogeographical setting of a specific region.

The Puerto Rico Component of the National Tsunami Hazard and Mitigation Program Pr-Nthmp

NASA Astrophysics Data System (ADS)

Huerfano Moreno, V. A.; Hincapie-Cardenas, C. M.

2014-12-01

Tsunami hazard assessment, detection, warning, education and outreach efforts are intended to reduce losses to life and property. The Puerto Rico Seismic Network (PRSN) is participating in an effort with local and federal agencies, to developing tsunami hazard risk reduction strategies under the National Tsunami Hazards and Mitigation Program (NTHMP). This grant supports the TsunamiReady program which is the base of the tsunami preparedness and mitigation in PR. The Caribbean region has a documented history of damaging tsunamis that have affected coastal areas. The seismic water waves originating in the prominent fault systems around PR are considered to be a near-field hazard for Puerto Rico and the Virgin islands (PR/VI) because they can reach coastal areas within a few minutes after the earthquake. Sources for local, regional and tele tsunamis have been identified and modeled and tsunami evacuation maps were prepared for PR. These maps were generated in three phases: First, hypothetical tsunami scenarios on the basis of the parameters of potential underwater earthquakes were developed. Secondly, each of these scenarios was simulated. The third step was to determine the worst case scenario (MOM). The run-ups were drawn on GIS referenced maps and aerial photographs. These products are being used by emergency managers to educate the public and develop mitigation strategies. Online maps and related evacuation products are available to the public via the PR-TDST (PR Tsunami Decision Support Tool). Currently all the 44 coastal municipalities were recognized as TsunamiReady by the US NWS. The main goal of the program is to declare Puerto Rico as TsunamiReady, including two cities that are not coastal but could be affected by tsunamis. Based on these evacuation maps, tsunami signs were installed, vulnerability profiles were created, communication systems to receive and disseminate tsunami messages were installed in each TWFP, and tsunami response plans were approved. Also, the existing tsunami protocol and criteria in the PR/VI was updated. This paper describes the PR-NTHMP project, including the real time earthquake and tsunami monitoring as well as the specific protocols used to broadcast tsunami messages. The paper highlights tsunami hazards assessment, detection, warning, education and outreach in Puerto Rico.

U.S. states and territories national tsunami hazard assessment, historic record and sources for waves

NASA Astrophysics Data System (ADS)

Dunbar, P. K.; Weaver, C.

2007-12-01

In 2005, the U.S. National Science and Technology Council (NSTC) released a joint report by the sub-committee on Disaster Reduction and the U.S. Group on Earth Observations titled Tsunami Risk Reduction for the United States: A Framework for Action (Framework). The Framework outlines the President's&pstrategy for reducing the United States tsunami risk. The first specific action called for in the Framework is to "Develop standardized and coordinated tsunami hazard and risk assessments for all coastal regions of the United States and its territories." Since NOAA is the lead agency for providing tsunami forecasts and warnings and NOAA's National Geophysical Data Center (NGDC) catalogs information on global historic tsunamis, NOAA/NGDC was asked to take the lead in conducting the first national tsunami hazard assessment. Earthquakes or earthquake-generated landslides caused more than 85% of the tsunamis in the NGDC tsunami database. Since the United States Geological Survey (USGS) conducts research on earthquake hazards facing all of the United States and its territories, NGDC and USGS partnered together to conduct the first tsunami hazard assessment for the United States and its territories. A complete tsunami hazard and risk assessment consists of a hazard assessment, exposure and vulnerability assessment of buildings and people, and loss assessment. This report is an interim step towards a tsunami risk assessment. The goal of this report is provide a qualitative assessment of the United States tsunami hazard at the national level. Two different methods are used to assess the U.S. tsunami hazard. The first method involves a careful examination of the NGDC historical tsunami database. This resulted in a qualitative national tsunami hazard assessment based on the distribution of runup heights and the frequency of runups. Although tsunami deaths are a measure of risk rather than hazard, the known tsunami deaths found in the NGDC database search were compared with the qualitative assessments based on frequency and amplitude. The second method to assess tsunami hazard involved using the USGS earthquake databases to search for possible earthquake sources near American coastlines to extend the NOAA/NGDC tsunami databases backward in time. The qualitative tsunami hazard assessment based on the results of the NGDC and USGS database searches will be presented.

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 conventional method based on the liner long wave theory, we found that the amplitudes of tsunamis are different from each other for the two simulations. The degree of the amplification of the height of tsunami in our method is larger than that in the conventional one. The height of the later phases of the tsunamis shows the discrepancy between the two results. We would like to conclude that the real changes of water depth affect the prediction of tsunami propagation and the maximum height. Because of the effects of the seafloor topography, the amplitude of the later phases is sometimes larger than the former ones. Due to the inclusion of such effects by the real topography, we believe our method lead to a higher accuracy of prediction of tsunami later phases, which would be effective for tsunami disaster mitigation.

Development of a decision support system for tsunami evacuation: application to the Jiyang District of Sanya city in China

NASA Astrophysics Data System (ADS)

Hou, Jingming; Yuan, Ye; Wang, Peitao; Ren, Zhiyuan; Li, Xiaojuan

2017-03-01

Major tsunami disasters often cause great damage in the first few hours following an earthquake. The possible severity of such events requires preparations to prevent tsunami disasters or mitigate them. This paper is an attempt to develop a decision support system for rapid tsunami evacuation for local decision makers. Based on the numerical results database of tsunami disasters, this system can quickly obtain the tsunami inundation and travel time. Because numerical models are calculated in advance, this system can reduce decision-making time. Population distribution, as a vulnerability factor, was analyzed to identify areas of high risk for tsunami disasters. Combined with spatial data, this system can comprehensively analyze the dynamic and static evacuation process and identify problems that negatively impact evacuation, thus supporting the decision-making for tsunami evacuation in high-risk areas. When an earthquake and tsunami occur, this system can rapidly obtain the tsunami inundation and travel time and provide information to assist with tsunami evacuation operations.

Tsunami risk mapping simulation for Malaysia

USGS Publications Warehouse

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.

Tsunami Defense Efforts at Samcheok Port, Korea

NASA Astrophysics Data System (ADS)

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

Tsunamis: stochastic models of occurrence and generation mechanisms

USGS Publications Warehouse

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.

2011 Tohoku, Japan tsunami data available from the National Oceanic and Atmospheric Administration/National Geophysical Data Center

NASA Astrophysics Data System (ADS)

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 faster and more accurate tsunami warnings. NOAA's National Data Buoy Center disseminates real-time DART® data and NGDC processes and archives post-event 15-second high-resolution bottom pressure time series data. An event-specific archive of DART® observations recorded during recent significant tsunamis, including the March 2011 Tohoku, Japan event, are now available through new tsunami event pages integrated with the NGDC global historical tsunami database. These pages are developed to deliver comprehensive summaries of each tsunami event, including socio-economic impacts, tsunami travel time maps, raw observations, de-tided residuals, spectra of the tsunami signal compared to the energy of the background noise, and wavelets. These data are invaluable to tsunami researchers and educators as they are essential to providing a more thorough understanding of tsunamis and their propagation in the open ocean and subsequent inundation of coastal communities. NGDC has collected 289 tide gauge observations, 34 Deep-ocean Assessment and Reporting of Tsunami (DART®) and bottom pressure recorder (BPR) station observations, and over 5,000 eyewitness reports and post-tsunami field survey measurements for the 2011 Tohoku event.

Real-time Tsunami Inundation Prediction Using High Performance Computers

NASA Astrophysics Data System (ADS)

Oishi, Y.; Imamura, F.; Sugawara, D.

2014-12-01

Recently off-shore tsunami observation stations based on cabled ocean bottom pressure gauges are actively being deployed especially in Japan. These cabled systems are designed to provide real-time tsunami data before tsunamis reach coastlines for disaster mitigation purposes. To receive real benefits of these observations, real-time analysis techniques to make an effective use of these data are necessary. A representative study was made by Tsushima et al. (2009) that proposed a method to provide instant tsunami source prediction based on achieving tsunami waveform data. As time passes, the prediction is improved by using updated waveform data. After a tsunami source is predicted, tsunami waveforms are synthesized from pre-computed tsunami Green functions of linear long wave equations. Tsushima et al. (2014) updated the method by combining the tsunami waveform inversion with an instant inversion of coseismic crustal deformation and improved the prediction accuracy and speed in the early stages. For disaster mitigation purposes, real-time predictions of tsunami inundation are also important. In this study, we discuss the possibility of real-time tsunami inundation predictions, which require faster-than-real-time tsunami inundation simulation in addition to instant tsunami source analysis. Although the computational amount is large to solve non-linear shallow water equations for inundation predictions, it has become executable through the recent developments of high performance computing technologies. We conducted parallel computations of tsunami inundation and achieved 6.0 TFLOPS by using 19,000 CPU cores. We employed a leap-frog finite difference method with nested staggered grids of which resolution range from 405 m to 5 m. The resolution ratio of each nested domain was 1/3. Total number of grid points were 13 million, and the time step was 0.1 seconds. Tsunami sources of 2011 Tohoku-oki earthquake were tested. The inundation prediction up to 2 hours after the earthquake occurs took about 2 minutes, which would be sufficient for a practical tsunami inundation predictions. In the presentation, the computational performance of our faster-than-real-time tsunami inundation model will be shown, and preferable tsunami wave source analysis for an accurate inundation prediction will also be discussed.

Bodrum-Kos (Turkey-Greece) Mw 6.6 earthquake and tsunami of 20 July 2017: a test for the Mediterranean tsunami warning system

NASA Astrophysics Data System (ADS)

Heidarzadeh, Mohammad; Necmioglu, Ocal; Ishibe, Takeo; Yalciner, Ahmet C.

2017-12-01

Various Tsunami Service Providers (TSPs) within the Mediterranean Basin supply tsunami warnings including CAT-INGV (Italy), KOERI-RETMC (Turkey), and NOA/HL-NTWC (Greece). The 20 July 2017 Bodrum-Kos (Turkey-Greece) earthquake (Mw 6.6) and tsunami provided an opportunity to assess the response from these TSPs. Although the Bodrum-Kos tsunami was moderate (e.g., runup of 1.9 m) with little damage to properties, it was the first noticeable tsunami in the Mediterranean Basin since the 21 May 2003 western Mediterranean tsunami. Tsunami waveform analysis revealed that the trough-to-crest height was 34.1 cm at the near-field tide gauge station of Bodrum (Turkey). Tsunami period band was 2-30 min with peak periods at 7-13 min. We proposed a source fault model for this tsunami with the length and width of 25 and 15 km and uniform slip of 0.4 m. Tsunami simulations using both nodal planes produced almost same results in terms of agreement between tsunami observations and simulations. Different TSPs provided tsunami warnings at 10 min (CAT-INGV), 19 min (KOERI-RETMC), and 18 min (NOA/HL-NTWC) after the earthquake origin time. Apart from CAT-INGV, whose initial Mw estimation differed 0.2 units with respect to the final value, the response from the other two TSPs came relatively late compared to the desired warning time of 10 min, given the difficulties for timely and accurate calculation of earthquake magnitude and tsunami impact assessment. It is argued that even if a warning time of 10 min was achieved, it might not have been sufficient for addressing near-field tsunami hazards. Despite considerable progress and achievements made within the upstream components of NEAMTWS (North East Atlantic, Mediterranean and Connected seas Tsunami Warning System), the experience from this moderate tsunami may highlight the need for improving operational capabilities of TSPs, but more importantly for effectively integrating civil protection authorities into NEAMTWS and strengthening tsunami education programs.

The TRIDEC Project: Future-Saving FOSS GIS Applications for Tsunami Early Warning

NASA Astrophysics Data System (ADS)

Loewe, P.; Wächter, J.; Hammitzsch, M.

2011-12-01

The Boxing Day Tsunami of 2004 killed over 240,000 people in 14 countries and inundated the affected shorelines with waves reaching heights up to 30m. This natural disaster coincided with an information catastrophy, as potentially life-saving early warning information existed, yet no means were available to deliver it to the communities under imminent threat. Tsunami Early Warning Capabilities have improved in the meantime by continuing development of modular Tsunami Early Warning Systems (TEWS). However, recent tsunami events, like the Chile 2010 and the Tohoku 2011 tsunami demonstrate that the key challenge for ongoing TEWS research on the supranational scale still lies in the timely issuing of reliable early warning messages. Since 2004, the GFZ German Research Centre for Geosciences has built up expertise in the field of TEWS. Within GFZ, the Centre for GeoInformation Technology (CEGIT) has focused its work on the geoinformatics aspects of TEWS in two projects already: The German Indonesian Tsunami Early Warning System (GITEWS) funded by the German Federal Ministry of Education and Research (BMBF) and the Distant Early Warning System (DEWS), a European project funded under the sixth Framework Programme (FP6). These developments are continued in the TRIDEC project (Collaborative, Complex, and Critical Decision Processes in Evolving Crises) funded under the European Union's seventh Framework Programme (FP7). This ongoing project focuses on real-time intelligent information management in Earth management and its long-term application. All TRIDEC developments are based on Free and Open Source Software (FOSS) components and industry standards where-ever possible. Tsunami Early Warning in TRIDEC is also based on mature system architecture models to ensure long-term usability and the flexibility to adapt to future generations of Tsunami sensors. All open source software produced by the project consortium are foreseen to be published on FOSSLAB, a publicly available software repository provided by CEGIT. FOSSLAB serves as a platform for the development of FOSS projects in geospatial context, allowing to save, advance and reuse results achieved in previous and on-going project activities and enabling further development and collaboration with a wide community including scientists, developers, users and stakeholders. FOSSLABs potential to preserve and advance existing best practices for reuse in new scenarios is documented by a first case study: For TEWS education and public outreach a comprehensive approach to generate high resolution globe maps was compiled using GRASS GIS and the POV-Ray rendering software. The task resulted in the merging of isolated technical know-how into publicly available best practices, which had been previously maintained in disparate GIS- and rendering communities. Beyond the scope of TRIDEC, FOSSLAB constitutes an umbrella encompassing several geoinformatics-related activities, such as the documentation of Best Practices for experiences and results while working with Spatial Data Infrastructures (SDI), Geographic Information Systems (GIS), Geomatics, and future spatial processing on Computation Clusters and in Cloud Computing.

Scenario-based tsunami risk assessment using a static flooding approach and high-resolution digital elevation data: An example from Muscat in Oman

NASA Astrophysics Data System (ADS)

Schneider, Bastian; Hoffmann, Gösta; Reicherter, Klaus

2016-04-01

Knowledge of tsunami risk and vulnerability is essential to establish a well-adapted Multi Hazard Early Warning System, land-use planning and emergency management. As the tsunami risk for the coastline of Oman is still under discussion and remains enigmatic, various scenarios based on historical tsunamis were created. The suggested inundation and run-up heights were projected onto the modern infrastructural setting of the Muscat Capital Area. Furthermore, possible impacts of the worst-case tsunami event for Muscat are discussed. The approved Papathoma Tsunami Vulnerability Assessment Model was used to model the structural vulnerability of the infrastructure for a 2 m tsunami scenario, depicting the 1945 tsunami and a 5 m tsunami in Muscat. Considering structural vulnerability, the results suggest a minor tsunami risk for the 2 m tsunami scenario as the flooding is mainly confined to beaches and wadis. Especially traditional brick buildings, still predominant in numerous rural suburbs, and a prevalently coast-parallel road network lead to an increased tsunami risk. In contrast, the 5 m tsunami scenario reveals extensively inundated areas and with up to 48% of the buildings flooded, and therefore consequently a significantly higher tsunami risk. We expect up to 60000 damaged buildings and up to 380000 residents directly affected in the Muscat Capital Area, accompanied with a significant loss of life and damage to vital infrastructure. The rapid urbanization processes in the Muscat Capital Area, predominantly in areas along the coast, in combination with infrastructural, demographic and economic growth will additionally increase the tsunami risk and therefore emphasizes the importance of tsunami risk assessment in Oman.

Tsunami Speed Variations in Density-stratified Compressible Global Oceans

NASA Astrophysics Data System (ADS)

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.

Seaside, Oregon, Tsunami Vulnerability Assessment Pilot Study

NASA Astrophysics Data System (ADS)

Dunbar, P. K.; Dominey-Howes, D.; Varner, J.

2006-12-01

The results of a pilot study to assess the risk from tsunamis for the Seaside-Gearhart, Oregon region will be presented. To determine the risk from tsunamis, it is first necessary to establish the hazard or probability that a tsunami of a particular magnitude will occur within a certain period of time. Tsunami inundation maps that provide 100-year and 500-year probabilistic tsunami wave height contours for the Seaside-Gearhart, Oregon, region were developed as part of an interagency Tsunami Pilot Study(1). These maps provided the probability of the tsunami hazard. The next step in determining risk is to determine the vulnerability or degree of loss resulting from the occurrence of tsunamis due to exposure and fragility. The tsunami vulnerability assessment methodology used in this study was developed by M. Papathoma and others(2). This model incorporates multiple factors (e.g. parameters related to the natural and built environments and socio-demographics) that contribute to tsunami vulnerability. Data provided with FEMA's HAZUS loss estimation software and Clatsop County, Oregon, tax assessment data were used as input to the model. The results, presented within a geographic information system, reveal the percentage of buildings in need of reinforcement and the population density in different inundation depth zones. These results can be used for tsunami mitigation, local planning, and for determining post-tsunami disaster response by emergency services. (1)Tsunami Pilot Study Working Group, Seaside, Oregon Tsunami Pilot Study--Modernization of FEMA Flood Hazard Maps, Joint NOAA/USGS/FEMA Special Report, U.S. National Oceanic and Atmospheric Administration, U.S. Geological Survey, U.S. Federal Emergency Management Agency, 2006, Final Draft. (2)Papathoma, M., D. Dominey-Howes, D.,Y. Zong, D. Smith, Assessing Tsunami Vulnerability, an example from Herakleio, Crete, Natural Hazards and Earth System Sciences, Vol. 3, 2003, p. 377-389.

The 2017 México Tsunami Record, Numerical Modeling and Threat Assessment in Costa Rica

NASA Astrophysics Data System (ADS)

Chacón-Barrantes, Silvia

2018-03-01

An M w 8.2 earthquake and tsunami occurred offshore the Pacific coast of México on 2017-09-08, at 04:49 UTC. Costa Rican tide gauges have registered a total of 21 local, regional and far-field tsunamis. The Quepos gauge registered 12 tsunamis between 1960 and 2014 before it was relocated inside a harbor by late 2014, where it registered two more tsunamis. This paper analyzes the 2017 México tsunami as recorded by the Quepos gauge. It took 2 h for the tsunami to arrive to Quepos, with a first peak height of 9.35 cm and a maximum amplitude of 18.8 cm occurring about 6 h later. As a decision support tool, this tsunami was modeled for Quepos in real time using ComMIT (Community Model Interface for Tsunami) with the finer grid having a resolution of 1 arcsec ( 30 m). However, the model did not replicate the tsunami record well, probably due to the lack of a finer and more accurate bathymetry. In 2014, the National Tsunami Monitoring System of Costa Rica (SINAMOT) was created, acting as a national tsunami warning center. The occurrence of the 2017 México tsunami raised concerns about warning dissemination mechanisms for most coastal communities in Costa Rica, due to its short travel time.

Uncertainty in tsunami sediment transport modeling

USGS Publications Warehouse

Jaffe, Bruce E.; Goto, Kazuhisa; Sugawara, Daisuke; Gelfenbaum, Guy R.; La Selle, SeanPaul M.

2016-01-01

Erosion and deposition from tsunamis record information about tsunami hydrodynamics and size that can be interpreted to improve tsunami hazard assessment. We explore sources and methods for quantifying uncertainty in tsunami sediment transport modeling. Uncertainty varies with tsunami, study site, available input data, sediment grain size, and model. Although uncertainty has the potential to be large, published case studies indicate that both forward and inverse tsunami sediment transport models perform well enough to be useful for deciphering tsunami characteristics, including size, from deposits. New techniques for quantifying uncertainty, such as Ensemble Kalman Filtering inversion, and more rigorous reporting of uncertainties will advance the science of tsunami sediment transport modeling. Uncertainty may be decreased with additional laboratory studies that increase our understanding of the semi-empirical parameters and physics of tsunami sediment transport, standardized benchmark tests to assess model performance, and development of hybrid modeling approaches to exploit the strengths of forward and inverse models.

Tsunami Preparedness in Washington (video)

USGS Publications Warehouse

Loeffler, Kurt; Gesell, Justine

2010-01-01

Tsunamis are a constant threat to the coasts of our world. Although tsunamis are infrequent along the West coast of the United States, it is possible and necessary to prepare for potential tsunami hazards to minimize loss of life and property. Community awareness programs are important, as they strive to create an informed society by providing education and training. This video about tsunami preparedness in Washington distinguishes between a local tsunami and a distant event and focus on the specific needs of this region. It offers guidelines for correct tsunami response and community preparedness from local emergency managers, first-responders, and leading experts on tsunami hazards and warnings, who have been working on ways of making the tsunami affected regions safer for the people and communities on a long-term basis. This video was produced by the US Geological Survey (USGS) in cooperation with Washington Emergency Management Division (EMD) and with funding by the National Tsunami Hazard Mitigation Program.

Science and Engineering of an Operational Tsunami Forecasting System

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gonzalez, Frank

2009-04-06

After a review of tsunami statistics and the destruction caused by tsunamis, a means of forecasting tsunamis is discussed as part of an overall program of reducing fatalities through hazard assessment, education, training, mitigation, and a tsunami warning system. The forecast is accomplished via a concept called Deep Ocean Assessment and Reporting of Tsunamis (DART). Small changes of pressure at the sea floor are measured and relayed to warning centers. Under development is an international modeling network to transfer, maintain, and improve tsunami forecast models.

Science and Engineering of an Operational Tsunami Forecasting System

ScienceCinema

Gonzalez, Frank

2017-12-09

After a review of tsunami statistics and the destruction caused by tsunamis, a means of forecasting tsunamis is discussed as part of an overall program of reducing fatalities through hazard assessment, education, training, mitigation, and a tsunami warning system. The forecast is accomplished via a concept called Deep Ocean Assessment and Reporting of Tsunamis (DART). Small changes of pressure at the sea floor are measured and relayed to warning centers. Under development is an international modeling network to transfer, maintain, and improve tsunami forecast models.

Health aspects of the Tsunami disaster in Asia.

PubMed

Kapila, Mukesh; McGarry, Nichole; Emerson, Elizabeth; Fink, Sheri; Doran, Rodger; Rejto, Khadija; Profili, Maria Cristina

2005-01-01

This is a summary of the proceedings of the Conference on the Health Aspects of the Tsunami Disaster in Asia that was convened by the World Health Organization in Phuket, Thailand from 04-06 May 2005. It contains reviews of the experiences of the health sector and early recovery following the Earthquake and Tsunami with emphasis on what was done well and what could have been done better and the lessons learned that can be incorporated into actions that will mitigate the damage created by future events. It outlines the national and international responses and recovery and the actions taken and not taken by the international community in support of the countries affected. Specific issues addressed include: (1) needs assessments; (2) coordination; (3) filling gaps in essential services, and (4) capacity building at the country level. Each of these aspects is analyzed as to its: (1) appropriateness; (2) adequacy; (3) effectiveness; (4) efficiency; and (5) connectedness. Much of what occurred provided benefits to the stricken population, but there is substantial room for improvement through implementation of the lessons learned. These lessons must be converted into actions in order to mitigate the damage sustained and to enhance our responses to the damage from future events.

Hydraulic experiment on tsunami sand deposits relating with grain size distribution and magnitude of incident waves

NASA Astrophysics Data System (ADS)

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.

Tsunami Hazard Assessment: Source regions of concern to U.S. interests derived from NOAA Tsunami Forecast Model Development

NASA Astrophysics Data System (ADS)

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.

Field survey of the 1 April 2014 Iquique tsunami along the coasts of Chile and Peru

NASA Astrophysics Data System (ADS)

Lagos, M.; Fritz, H. M.

2014-12-01

On 1 April, 2014 a magnitude Mw 8.2 earthquake occurred off the coast of northern Chile less than 100 km NW of Iquique within a region of historic quiescence termed the northern Chile seismic gap. The ensuing tsunami inundation caused mostly minor damage centered in Iquique and neighbouring stretches of coastline. Fortunately, ancestral knowledge from the past 1868 and 1877 tsunamis in the region along with the recent 2010 Maule tsunami, as well as tsunami education and evacuation exercises prompted most coastal residents to spontaneously evacuate to high ground after the earthquake. There were no tsunami victims, while a handful of fatalities were associated to the earthquake and the tsunami evacuation. The local scientist deployed in the morning hours to start the tsunami survey in Iquique on the day after the earthquake. The international scientist joined the local effort from April 6 to 11. The international tsunami survey team (ITST) documented flow depths, runup heights, inundation distances, sediment deposition, damage patterns, performance of the navigation infrastructure and impact on the natural environment. The ITST covered a 700 km stretch of coastline from the Mejillones Peninsula (23.5° S) north of Antofagasta in Chile up to Vila Vila (18.1° S) in southern Peru. We surveyed 30 locations with differential GPS and laser range finders. The tsunami impact peaked in the vicinity of Iquique exceeding 4 m in tsunami height. A significant variation in tsunami impact was observed along the coastlines of Chile and Peru both at local and regional scales. The tsunami occurred in the evening hours limiting the availability of eyewitness video footages. Observations from the 2014 Chile tsunami are compared against the 1868, 1877 and 2010 Chile tsunamis. Given the magnitude of the 1 April 2014 earthquake the tsunami could have been significantly larger. However the absence of a massive tsunami may mislead residents in the future to believe another minor tsunami may be generated after an earthquake of similar magnitude. Hence the April fool's day event poses significant challenges to community-based education. The team interviewed numerous eyewitnesses and educated residents about tsunami hazards since awareness programs are essential to save lives in locales at risk from locally generated tsunamis.

A Global Sensitivity Analysis Method on Maximum Tsunami Wave Heights to Potential Seismic Source Parameters

NASA Astrophysics Data System (ADS)

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 exist differences in importance order in generating uncertainties of the maximum tsunami wave heights for same group parameters at different specific sites in offshore area. These results are helpful to deeply understand the relationship between the tsunami wave heights and the seismic tsunami source parameters. Keywords: Global sensitivity analysis; Tsunami wave height; Potential seismic tsunami source parameter; Morris method; Extended FAST method

Rapid Determination of Appropriate Source Models for Tsunami Early Warning using a Depth Dependent Rigidity Curve: Method and Numerical Tests

NASA Astrophysics Data System (ADS)

Tanioka, Y.; Miranda, G. J. A.; Gusman, A. R.

2017-12-01

Recently, tsunami early warning technique has been improved using tsunami waveforms observed at the ocean bottom pressure gauges such as NOAA DART system or DONET and S-NET systems in Japan. However, for tsunami early warning of near field tsunamis, it is essential to determine appropriate source models using seismological analysis before large tsunamis hit the coast, especially for tsunami earthquakes which generated significantly large tsunamis. In this paper, we develop a technique to determine appropriate source models from which appropriate tsunami inundation along the coast can be numerically computed The technique is tested for four large earthquakes, the 1992 Nicaragua tsunami earthquake (Mw7.7), the 2001 El Salvador earthquake (Mw7.7), the 2004 El Astillero earthquake (Mw7.0), and the 2012 El Salvador-Nicaragua earthquake (Mw7.3), which occurred off Central America. In this study, fault parameters were estimated from the W-phase inversion, then the fault length and width were determined from scaling relationships. At first, the slip amount was calculated from the seismic moment with a constant rigidity of 3.5 x 10**10N/m2. The tsunami numerical simulation was carried out and compared with the observed tsunami. For the 1992 Nicaragua tsunami earthquake, the computed tsunami was much smaller than the observed one. For the 2004 El Astillero earthquake, the computed tsunami was overestimated. In order to solve this problem, we constructed a depth dependent rigidity curve, similar to suggested by Bilek and Lay (1999). The curve with a central depth estimated by the W-phase inversion was used to calculate the slip amount of the fault model. Using those new slip amounts, tsunami numerical simulation was carried out again. Then, the observed tsunami heights, run-up heights, and inundation areas for the 1992 Nicaragua tsunami earthquake were well explained by the computed one. The other tsunamis from the other three earthquakes were also reasonably well explained by the computed ones. Therefore, our technique using a depth dependent rigidity curve is worked to estimate an appropriate fault model which reproduces tsunami heights near the coast in Central America. The technique may be worked in the other subduction zones by finding a depth dependent rigidity curve in that particular subduction zone.

Bayesian inference and interpretation of centroid moment tensors of the 2016 Kumamoto earthquake sequence, Kyushu, Japan

NASA Astrophysics Data System (ADS)

Hallo, Miroslav; Asano, Kimiyuki; Gallovič, František

2017-09-01

On April 16, 2016, Kumamoto prefecture in Kyushu region, Japan, was devastated by a shallow M JMA7.3 earthquake. The series of foreshocks started by M JMA6.5 foreshock 28 h before the mainshock. They have originated in Hinagu fault zone intersecting the mainshock Futagawa fault zone; hence, the tectonic background for this earthquake sequence is rather complex. Here we infer centroid moment tensors (CMTs) for 11 events with M JMA between 4.8 and 6.5, using strong motion records of the K-NET, KiK-net and F-net networks. We use upgraded Bayesian full-waveform inversion code ISOLA-ObsPy, which takes into account uncertainty of the velocity model. Such an approach allows us to reliably assess uncertainty of the CMT parameters including the centroid position. The solutions show significant systematic spatial and temporal variations throughout the sequence. Foreshocks are right-lateral steeply dipping strike-slip events connected to the NE-SW shear zone. Those located close to the intersection of the Hinagu and Futagawa fault zones are dipping slightly to ESE, while those in the southern area are dipping to WNW. Contrarily, aftershocks are mostly normal dip-slip events, being related to the N-S extensional tectonic regime. Most of the deviatoric moment tensors contain only minor CLVD component, which can be attributed to the velocity model uncertainty. Nevertheless, two of the CMTs involve a significant CLVD component, which may reflect complex rupture process. Decomposition of those moment tensors into two pure shear moment tensors suggests combined right-lateral strike-slip and normal dip-slip mechanisms, consistent with the tectonic settings of the intersection of the Hinagu and Futagawa fault zones.[Figure not available: see fulltext.

An Evaluation of Understandability of Patient Journey Models in Mental Health.

PubMed

Percival, Jennifer; McGregor, Carolyn

2016-07-28

There is a significant trend toward implementing health information technology to reduce administrative costs and improve patient care. Unfortunately, little awareness exists of the challenges of integrating information systems with existing clinical practice. The systematic integration of clinical processes with information system and health information technology can benefit the patients, staff, and the delivery of care. This paper presents a comparison of the degree of understandability of patient journey models. In particular, the authors demonstrate the value of a relatively new patient journey modeling technique called the Patient Journey Modeling Architecture (PaJMa) when compared with traditional manufacturing based process modeling tools. The paper also presents results from a small pilot case study that compared the usability of 5 modeling approaches in a mental health care environment. Five business process modeling techniques were used to represent a selected patient journey. A mix of both qualitative and quantitative methods was used to evaluate these models. Techniques included a focus group and survey to measure usability of the various models. The preliminary evaluation of the usability of the 5 modeling techniques has shown increased staff understanding of the representation of their processes and activities when presented with the models. Improved individual role identification throughout the models was also observed. The extended version of the PaJMa methodology provided the most clarity of information flows for clinicians. The extended version of PaJMa provided a significant improvement in the ease of interpretation for clinicians and increased the engagement with the modeling process. The use of color and its effectiveness in distinguishing the representation of roles was a key feature of the framework not present in other modeling approaches. Future research should focus on extending the pilot case study to a more diversified group of clinicians and health care support workers.

Novel blaROB-1-Bearing Plasmid Conferring Resistance to β-Lactams in Haemophilus parasuis Isolates from Healthy Weaning Pigs

PubMed Central

Moleres, Javier; Santos-López, Alfonso; Lázaro, Isidro; Labairu, Javier; Prat, Cristina; Ardanuy, Carmen; González-Zorn, Bruno

2015-01-01

Haemophilus parasuis, the causative agent of Glässer's disease, is one of the early colonizers of the nasal mucosa of piglets. It is prevalent in swine herds, and lesions associated with disease are fibrinous polyserositis and bronchopneumonia. Antibiotics are commonly used in disease control, and resistance to several antibiotics has been described in H. parasuis. Prediction of H. parasuis virulence is currently limited by our scarce understanding of its pathogenicity. Some genes have been associated with H. parasuis virulence, such as lsgB and group 1 vtaA, while biofilm growth has been associated with nonvirulent strains. In this study, 86 H. parasuis nasal isolates from farms that had not had a case of disease for more than 10 years were obtained by sampling piglets at weaning. Isolates were studied by enterobacterial repetitive intergenic consensus PCR and determination of the presence of lsgB and group 1 vtaA, biofilm formation, inflammatory cell response, and resistance to antibiotics. As part of the diversity encountered, a novel 2,661-bp plasmid, named pJMA-1, bearing the blaROB-1 β-lactamase was detected in eight colonizing strains. pJMA-1 was shown to share a backbone with other small plasmids described in the Pasteurellaceae, to be 100% stable, and to have a lower biological cost than the previously described plasmid pB1000. pJMA-1 was also found in nine H. parasuis nasal strains from a separate collection, but it was not detected in isolates from the lesions of animals with Glässer's disease or in nontypeable Haemophilus influenzae isolates. Altogether, we show that commensal H. parasuis isolates represent a reservoir of β-lactam resistance genes which can be transferred to pathogens or other bacteria. PMID:25747001

Simulation of landslide and tsunami of the 1741 Oshima-Oshima eruption in Hokkaido, Japan

NASA Astrophysics Data System (ADS)

Ioki, K.; Yanagisawa, H.; Tanioka, Y.; Kawakami, G.; Kase, Y.; Nishina, K.; Hirose, W.; Ishimaru, S.

2017-12-01

The 1741 tsunami was generated by the Oshima-Oshima sector collapse in the southwestern Hokkaido, Japan. The tsunami caused great damage along the coast of Japan Sea in Oshima and Tsugaru peninsula and was the largest scale generated in the Japan sea. By the survey of tsunami deposits, at the coast of Okushiri Island and Hiyama in Hokkaido, tsunami deposits of this tsunami were found. In this study, the landslide and tsunami by the Oshima-Oshima eruption were modeled to explain distribution of debris deposits, tsunami heights by historical records, and distribution of tsunami deposits. First, region of landslide and debris deposits were made out from the bathymetry based on the bathymetry survey data (Satake and Kato, 2001) in the north slope of Oshima-Oshima. In addition, topography before the sector collapse and landslide volume were re-estimated. The volume of landslide was estimated at 2.2 km3. Based on those data, the landslide and tsunami were simulated using two-layer model considered soil mass and water mass. The model was made improvements the integrated model of landslide and tsunami (Yanagisawa et al., 2014). The angle of internal friction was calculated 4 cases, included the bottom friction term in soil mass, to affect the movement of landslide. The Manning's roughness coefficient was calculated 5 cases, included the bottom friction term in soil mass, to affect the generation of tsunami. By the parameter study, optimal solutions were found. As the results, soil mass slid slowly submarine slope and stopped after about 15 minutes. Distribution of computed debris deposits agree relatively well with region of debris deposits made out from the bathymetry. On the other hand, the first wave of tsunami was generated during 1 minute that soil mass was sliding. Calculated tsunami heights match with historical records along the coast of Okushiri and Hiyama in Hokkaido. Calculated inundation area of tsunami cover distribution of tsunami deposits found by tsunami deposits survey in Okushiri and Hiyama coast.

Highly variable recurrence of tsunamis in the 7,400 years before the 2004 Indian Ocean tsunami

NASA Astrophysics Data System (ADS)

Horton, B.; Rubin, C. M.; Sieh, K.; Jessica, P.; Daly, P.; Ismail, N.; Parnell, A. C.

2017-12-01

The devastating 2004 Indian Ocean tsunami caught millions of coastal residents and the scientific community off-guard. Subsequent research in the Indian Ocean basin has identified prehistoric tsunamis, but the timing and recurrence intervals of such events are uncertain. Here, we identify coastal caves as a new depositional environment for reconstructing tsunami records and present a 5,000 year record of continuous tsunami deposits from a coastal cave in Sumatra, Indonesia which shows the irregular recurrence of 11 tsunamis between 7,400 and 2,900 years BP. The data demonstrates that the 2004 tsunami was just the latest in a sequence of devastating tsunamis stretching back to at least the early Holocene and suggests a high likelihood for future tsunamis in the Indian Ocean. The sedimentary record in the cave shows that ruptures of the Sunda megathrust vary between large (which generated the 2004 Indian Ocean tsunami) and smaller slip failures. The chronology of events suggests the recurrence of multiple smaller tsunamis within relatively short time periods, interrupted by long periods of strain accumulation followed by giant tsunamis. The average time period between tsunamis is about 450 years with intervals ranging from a long, dormant period of over 2,000 years, to multiple tsunamis within the span of a century. The very long dormant period suggests that the Sunda megathrust is capable of accumulating large slip deficits between earthquakes. Such a high slip rupture would produce a substantially larger earthquake than the 2004 event. Although there is evidence that the likelihood of another tsunamigenic earthquake in Aceh province is high, these variable recurrence intervals suggest that long dormant periods may follow Sunda Megathrust ruptures as large as that of 2004 Indian Ocean tsunami. The remarkable variability of recurrence suggests that regional hazard mitigation plans should be based upon the high likelihood of future destructive tsunami demonstrated by the cave record and other paleotsunami sites, rather than estimates of recurrence intervals.

Role of sediment transport model to improve the tsunami numerical simulation

NASA Astrophysics Data System (ADS)

Sugawara, D.; Yamashita, K.; Takahashi, T.; Imamura, F.

2015-12-01

Are we overlooking an important factor for improved numerical prediction of tsunamis in shallow sea to onshore? In this presentation, several case studies on numerical modeling of tsunami-induced sediment transport are reviewed, and the role of sediment transport models for tsunami inundation simulation is discussed. Large-scale sediment transport and resulting geomorphological change occurred in the coastal areas of Tohoku, Japan, due to the 2011 Tohoku Earthquake Tsunami. Datasets obtained after the tsunami, including geomorphological and sedimentological data as well as hydrodynamic records, allows us to validate the numerical model in detail. The numerical modeling of the sediment transport by the 2011 tsunami depicted the severest erosion of sandy beach, as well as characteristic spatial patterns of erosion and deposition on the seafloor, which have taken place in Hirota Bay, Sanriku Coast. Quantitative comparisons of observation and simulation of the geomorphological changes in Sanriku Coast and Sendai Bay showed that the numerical model can predict the volumes of erosion and deposition with a right order. In addition, comparison of the simulation with aerial video footages demonstrated the numerical model is capable of tracking the overall processes of tsunami sediment transport. Although tsunami-induced sediment erosion and deposition sometimes cause significant geomorphological change, and may enhance tsunami hydrodynamic impact to the coastal zones, most tsunami simulations do not include sediment transport modeling. A coupled modeling of tsunami hydrodynamics and sediment transport draws a different picture of tsunami hazard, comparing with simple hydrodynamic modeling of tsunami inundation. Since tsunami-induced erosion, deposition and geomorphological change sometimes extend more than several kilometers across the coastline, two-dimensional horizontal model are typically used for the computation of tsunami hydrodynamics and sediment transport. Limitations of the conventional model and future challenges are discussed regarding further improvement of numerical modeling of tsunami and sediment transport. Improved numerical modeling may provide useful information for assessing sediment-related damages and planning post-disaster recovery.

A Hybrid Tsunami Risk Model for Japan

NASA Astrophysics Data System (ADS)

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.

Uncertainty in the Modeling of Tsunami Sediment Transport

NASA Astrophysics Data System (ADS)

Jaffe, B. E.; Sugawara, D.; Goto, K.; Gelfenbaum, G. R.; La Selle, S.

2016-12-01

Erosion and deposition from tsunamis record information about tsunami hydrodynamics and size that can be interpreted to improve tsunami hazard assessment. A recent study (Jaffe et al., 2016) explores sources and methods for quantifying uncertainty in tsunami sediment transport modeling. Uncertainty varies with tsunami properties, study site characteristics, available input data, sediment grain size, and the model used. Although uncertainty has the potential to be large, case studies for both forward and inverse models have shown that sediment transport modeling provides useful information on tsunami inundation and hydrodynamics that can be used to improve tsunami hazard assessment. New techniques for quantifying uncertainty, such as Ensemble Kalman Filtering inversion, and more rigorous reporting of uncertainties will advance the science of tsunami sediment transport modeling. Uncertainty may be decreased with additional laboratory studies that increase our understanding of the semi-empirical parameters and physics of tsunami sediment transport, standardized benchmark tests to assess model performance, and the development of hybrid modeling approaches to exploit the strengths of forward and inverse models. As uncertainty in tsunami sediment transport modeling is reduced, and with increased ability to quantify uncertainty, the geologic record of tsunamis will become more valuable in the assessment of tsunami hazard. Jaffe, B., Goto, K., Sugawara, D., Gelfenbaum, G., and La Selle, S., "Uncertainty in Tsunami Sediment Transport Modeling", Journal of Disaster Research Vol. 11 No. 4, pp. 647-661, 2016, doi: 10.20965/jdr.2016.p0647 https://www.fujipress.jp/jdr/dr/dsstr001100040647/

Field survey of the 16 September 2015 Chile tsunami

NASA Astrophysics Data System (ADS)

Lagos, Marcelo; Fritz, Hermann M.

2016-04-01

On the evening of 16 September, 2015 a magnitude Mw 8.3 earthquake occurred off the coast of central Chile's Coquimbo region. The ensuing tsunami caused significant inundation and damage in the Coquimbo or 4th region and mostly minor effects in neighbouring 3rd and 5th regions. Fortunately, ancestral knowledge from the past 1922 and 1943 tsunamis in the region along with the catastrophic 2010 Maule and recent 2014 tsunamis, as well as tsunami education and evacuation exercises prompted most coastal residents to spontaneously evacuate to high ground after the earthquake. There were a few tsunami victims; while a handful of fatalities were associated to earthquake induced building collapses and the physical stress of tsunami evacuation. The international scientist joined the local effort from September 20 to 26, 2015. The international tsunami survey team (ITST) interviewed numerous eyewitnesses and documented flow depths, runup heights, inundation distances, sediment deposition, damage patterns, performance of the navigation infrastructure and impact on the natural environment. The ITST covered a 500 km stretch of coastline from Caleta Chañaral de Aceituno (28.8° S) south of Huasco down to Llolleo near San Antonio (33.6° S). We surveyed more than 40 locations and recorded more than 100 tsunami and runup heights with differential GPS and integrated laser range finders. The tsunami impact peaked at Caleta Totoral near Punta Aldea with both tsunami and runup heights exceeding 10 m as surveyed on September 22 and broadcasted nationwide that evening. Runup exceeded 10 m at a second uninhabited location some 15 km south of Caleta Totoral. A significant variation in tsunami impact was observed along the coastlines of central Chile at local and regional scales. The tsunami occurred in the evening hours limiting the availability of eyewitness video footages. Observations from the 2015 Chile tsunami are compared against the 1922, 1943, 2010 and 2014 Chile tsunamis. The tsunami was characterized by rapid arrival within minutes in the nearfield requiring spontaneous self-evacuation as warning messages did not reach some of the hardest hit fishing villages prior to tsunami arrival. The absence of a massive tsunami outside of the 4th region may mislead evacuated residents in the adjacent 3rd and 5th regions of Chile in potential future events. This event poses significant challenges to community-based education raising tsunami awareness. The team educated residents about tsunami hazards since awareness programs are essential to save lives in locales at risk from near-field tsunamis.

Evolution of tsunami warning systems and products.

PubMed

Bernard, Eddie; Titov, Vasily

2015-10-28

Each year, about 60 000 people and $4 billion (US$) in assets are exposed to the global tsunami hazard. Accurate and reliable tsunami warning systems have been shown to provide a significant defence for this flooding hazard. However, the evolution of warning systems has been influenced by two processes: deadly tsunamis and available technology. In this paper, we explore the evolution of science and technology used in tsunami warning systems, the evolution of their products using warning technologies, and offer suggestions for a new generation of warning products, aimed at the flooding nature of the hazard, to reduce future tsunami impacts on society. We conclude that coastal communities would be well served by receiving three standardized, accurate, real-time tsunami warning products, namely (i) tsunami energy estimate, (ii) flooding maps and (iii) tsunami-induced harbour current maps to minimize the impact of tsunamis. Such information would arm communities with vital flooding guidance for evacuations and port operations. The advantage of global standardized flooding products delivered in a common format is efficiency and accuracy, which leads to effectiveness in promoting tsunami resilience at the community level. © 2015 The Authors.

Evolution of tsunami warning systems and products

PubMed Central

Bernard, Eddie; Titov, Vasily

2015-01-01

Each year, about 60 000 people and $4 billion (US$) in assets are exposed to the global tsunami hazard. Accurate and reliable tsunami warning systems have been shown to provide a significant defence for this flooding hazard. However, the evolution of warning systems has been influenced by two processes: deadly tsunamis and available technology. In this paper, we explore the evolution of science and technology used in tsunami warning systems, the evolution of their products using warning technologies, and offer suggestions for a new generation of warning products, aimed at the flooding nature of the hazard, to reduce future tsunami impacts on society. We conclude that coastal communities would be well served by receiving three standardized, accurate, real-time tsunami warning products, namely (i) tsunami energy estimate, (ii) flooding maps and (iii) tsunami-induced harbour current maps to minimize the impact of tsunamis. Such information would arm communities with vital flooding guidance for evacuations and port operations. The advantage of global standardized flooding products delivered in a common format is efficiency and accuracy, which leads to effectiveness in promoting tsunami resilience at the community level. PMID:26392620

Tsunami hazard assessment in the southern Colombian Pacific basin and a proposal to regenerate a previous barrier island as protection

NASA Astrophysics Data System (ADS)

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.

Tsunami hazard assessment in the southern Colombian Pacific Basin and a proposal to regenerate a previous barrier island as protection

NASA Astrophysics Data System (ADS)

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.

Tsunamigenic potential of a newly discovered active fault zone in the outer Messina Strait, Southern Italy

NASA Astrophysics Data System (ADS)

Fu, Lili; Heidarzadeh, Mohammad; Cukur, Deniz; Chiocci, Francesco L.; Ridente, Domenico; Gross, Felix; Bialas, Jörg; Krastel, Sebastian

2017-03-01

The 1908 Messina tsunami was the most catastrophic tsunami hitting the coastline of Southern Italy in the younger past. The source of this tsunami, however, is still heavily debated, and both rupture along a fault and a slope failure have been postulated as potential origin of the tsunami. Here we report a newly discovered active Fiumefreddo-Melito di Porto Salvo Fault Zone (F-MPS_FZ), which is located in the outer Messina Strait in a proposed landslide source area of the 1908 Messina tsunami. Tsunami modeling showed that this fault zone would produce devastating tsunamis by assuming slip amounts of ≥5 m. An assumed slip of up to 17 m could even generate a tsunami comparable to the 1908 Messina tsunami, but we do not consider the F-MPS_FZ as a source for the 1908 Messina tsunami because its E-W strike contradicts seismological observations of the 1908 Messina earthquake. Future researches on the F-MPS_FZ, however, may contribute to the tsunami risk assessment in the Messina Strait.

Tsunami evacuation plans for future megathrust earthquakes in Padang, Indonesia, considering stochastic earthquake scenarios

NASA Astrophysics Data System (ADS)

Muhammad, Ario; Goda, Katsuichiro; Alexander, Nicholas A.; Kongko, Widjo; Muhari, Abdul

2017-12-01

This study develops tsunami evacuation plans in Padang, Indonesia, using a stochastic tsunami simulation method. The stochastic results are based on multiple earthquake scenarios for different magnitudes (Mw 8.5, 8.75, and 9.0) that reflect asperity characteristics of the 1797 historical event in the same region. The generation of the earthquake scenarios involves probabilistic models of earthquake source parameters and stochastic synthesis of earthquake slip distributions. In total, 300 source models are generated to produce comprehensive tsunami evacuation plans in Padang. The tsunami hazard assessment results show that Padang may face significant tsunamis causing the maximum tsunami inundation height and depth of 15 and 10 m, respectively. A comprehensive tsunami evacuation plan - including horizontal evacuation area maps, assessment of temporary shelters considering the impact due to ground shaking and tsunami, and integrated horizontal-vertical evacuation time maps - has been developed based on the stochastic tsunami simulation results. The developed evacuation plans highlight that comprehensive mitigation policies can be produced from the stochastic tsunami simulation for future tsunamigenic events.

Implications of the 26 December 2004 Sumatra-Andaman earthquake on tsunami forecast and assessment models for great subduction-zone earthquakes

USGS Publications Warehouse

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 exponential time constant of slip is less than approximately 1 hr. Overall, there is significant variation in assessed runup heights caused by quantifiable uncertainty in both first-order source parameters (e.g., rupture length, slip-length scaling) and spatiotemporal complexity of earthquake rupture.

Field Survey of the 2015 Ilapel Tsunami in North Central Chile

NASA Astrophysics Data System (ADS)

Lagos, M.; Fritz, H. M.

2016-12-01

The magnitude Mw 8.3 earthquake in north-central Chile on September 16, 2015 generated a tsunami that rapidly flooded coastal areas. The tsunami impact was concentrated in Coquimbo region, while the regions of Valparaiso and Atacama were also affected. Fortunately, ancestral knowledge from the past tsunamis in the region, as well as tsunami education and evacuation exercises prompted most coastal residents to spontaneously evacuate to high ground after the earthquake. The event caused 11 fatalities: 8 were associated with the tsunami, while 3 were attributed to building collapses caused by the earthquake. The international scientist joined the local effort from September 20 to 26, 2015. The international tsunami survey team (ITST) interviewed numerous eyewitnesses and documented flow depths, runup heights, inundation distances, sediment deposition, damage patterns, performance of the navigation infrastructure and impact on the natural environment. The ITST covered a 500 km stretch of coastline from Caleta Chañaral de Aceituno (28.8° S) south of Huasco down to Llolleo near San Antonio (33.6° S). We surveyed more than 40 locations and recorded more than 100 tsunami and runup heights with differential GPS and integrated laser range finders. The tsunami impact peaked at Caleta Totoral near Punta Aldea with both tsunami and runup heights exceeding 10 m as surveyed on September 22. Runup exceeded 10 m at a second uninhabited location some 15 km south of Caleta Totoral. A significant variation in tsunami impact was observed along the coastlines of central Chile at local and regional scales. The tsunami occurred in the evening hours limiting the availability of eyewitness video footages. Observations from the 2015 Chile tsunami are compared with recent Chilean tsunamis. The tsunami was characterized by rapid arrival within minutes in the nearfield requiring spontaneous self-evacuation as warning messages did not reach some of the hardest hit fishing villages prior to tsunami arrival. The absence of a massive tsunami outside of the Coquimbo region may mislead evacuated residents in the adjacent Atacama and Valparaíso regions of Chile in potential future events. This event poses significant challenges to community-based education raising tsunami awareness.

77 FR 16098 - In the Matter of All Operating Boiling Water Reactor Licensees With Mark I and Mark II...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-03-19

... height, which inundated the Fukushima Dai-ichi nuclear power plant site. The earthquake and tsunami... and industry in the northeastern coastal areas of Japan. When the earthquake occurred, Fukushima Dai... Nuclear Accident at the Fukushima Daiichi Nuclear Power Station, Revision 0,'' issued November 2011, p. 72...

Variety of Sedimentary Process and Distribution of Tsunami Deposits in Laboratory Experiments

NASA Astrophysics Data System (ADS)

Yamaguchi, N.; Sekiguchi, T.

2017-12-01

As an indicator of the history and magnitude of paleotsunami events, tsunami deposits have received considerable attention. To improve the identification and interpretation of paleotsunami deposits, an understanding of sedimentary process and distribution of tsunami deposits is crucial. Recent detailed surveys of onshore tsunami deposits including the 2004 Indian Ocean tsunami and the 2011 Tohoku-oki tsunami have revealed that terrestrial topography causes a variety of their features and distributions. Therefore, a better understanding of possible sedimentary process and distribution on such influential topographies is required. Flume experiments, in which sedimentary conditions can be easily controlled, can provide insights into the effects of terrestrial topography as well as tsunami magnitude on the feature of tsunami deposits. In this presentation, we report laboratory experiments that focused on terrestrial topography including a water body (e.g. coastal lake) on a coastal lowland and a cliff. In both cases, the results suggested relationship between the distribution of tsunami deposits and the hydraulic condition of the tsunami flow associated with the terrestrial topography. These experiments suggest that influential topography would enhance the variability in thickness of tsunami deposits, and thus, in reconstructions of paleotsunami events using sedimentary records, we should take into account such anomalous distribution of tsunami deposits. Further examination of the temporal sequence of sedimentary process in laboratory tsunamis may improve interpretation and estimation of paleotsunami events.

Open-Ocean and Coastal Properties of Recent Major Tsunamis

NASA Astrophysics Data System (ADS)

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).

Sedimentological effects of tsunamis, with particular reference to impact-generated and volcanogenic waves

NASA Technical Reports Server (NTRS)

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.

Modeling of influence from remote tsunami at the coast of Sakhalin and Kuriles islands.

NASA Astrophysics Data System (ADS)

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.

Development Of New Databases For Tsunami Hazard Analysis In California

NASA Astrophysics Data System (ADS)

Wilson, R. I.; Barberopoulou, A.; Borrero, J. C.; Bryant, W. A.; Dengler, L. A.; Goltz, J. D.; Legg, M.; McGuire, T.; Miller, K. M.; Real, C. R.; Synolakis, C.; Uslu, B.

2009-12-01

The California Geological Survey (CGS) has partnered with other tsunami specialists to produce two statewide databases to facilitate the evaluation of tsunami hazard products for both emergency response and land-use planning and development. A robust, State-run tsunami deposit database is being developed that compliments and expands on existing databases from the National Geophysical Data Center (global) and the USGS (Cascadia). Whereas these existing databases focus on references or individual tsunami layers, the new State-maintained database concentrates on the location and contents of individual borings/trenches that sample tsunami deposits. These data provide an important observational benchmark for evaluating the results of tsunami inundation modeling. CGS is collaborating with and sharing the database entry form with other states to encourage its continued development beyond California’s coastline so that historic tsunami deposits can be evaluated on a regional basis. CGS is also developing an internet-based, tsunami source scenario database and forum where tsunami source experts and hydrodynamic modelers can discuss the validity of tsunami sources and their contribution to hazard assessments for California and other coastal areas bordering the Pacific Ocean. The database includes all distant and local tsunami sources relevant to California starting with the forty scenarios evaluated during the creation of the recently completed statewide series of tsunami inundation maps for emergency response planning. Factors germane to probabilistic tsunami hazard analyses (PTHA), such as event histories and recurrence intervals, are also addressed in the database and discussed in the forum. Discussions with other tsunami source experts will help CGS determine what additional scenarios should be considered in PTHA for assessing the feasibility of generating products of value to local land-use planning and development.

Multi-dimensional knowledge translation: enabling health informatics capacity audits using patient journey models.

PubMed

Catley, Christina; McGregor, Carolyn; Percival, Jennifer; Curry, Joanne; James, Andrew

2008-01-01

This paper presents a multi-dimensional approach to knowledge translation, enabling results obtained from a survey evaluating the uptake of Information Technology within Neonatal Intensive Care Units to be translated into knowledge, in the form of health informatics capacity audits. Survey data, having multiple roles, patient care scenarios, levels, and hospitals, is translated using a structured data modeling approach, into patient journey models. The data model is defined such that users can develop queries to generate patient journey models based on a pre-defined Patient Journey Model architecture (PaJMa). PaJMa models are then analyzed to build capacity audits. Capacity audits offer a sophisticated view of health informatics usage, providing not only details of what IT solutions a hospital utilizes, but also answering the questions: when, how and why, by determining when the IT solutions are integrated into the patient journey, how they support the patient information flow, and why they improve the patient journey.

Hydraulic experimental investigation on spatial distribution and formation process of tsunami deposit on a slope

NASA Astrophysics Data System (ADS)

Harada, K.; Takahashi, T.; Yamamoto, A.; Sakuraba, M.; Nojima, K.

2017-12-01

An important aim of the study of tsunami deposits is to estimate the characteristics of past tsunamis from the tsunami deposits found locally. Based on the tsunami characteristics estimated from tsunami deposit, it is possible to examine tsunami risk assessment in coastal areas. It is considered that tsunami deposits are formed based on the dynamic correlation between tsunami's hydraulic values, sediment particle size, topography, etc. However, it is currently not enough to evaluate the characteristics of tsunamis from tsunami deposits. This is considered to be one of the reasons that the understanding of the formation process of tsunami deposits is not sufficiently understood. In this study, we analyze the measurement results of hydraulic experiment (Yamamoto et al., 2016) and focus on the formation process and distribution of tsunami deposits. Hydraulic experiment was conducted with two-dimensional water channel with a slope. Tsunami was inputted as a bore wave flow. The moving floor section was installed as a seabed slope connecting to shoreline and grain size distribution was set some cases. The water level was measured using ultrasonic displacement gauges, and the flow velocity was measured using propeller current meters and an electromagnetic current meter. The water level and flow velocity was measured at some points. The distribution of tsunami deposit was measured from shoreline to run-up limit on the slope. Yamamoto et al. (2016) reported the measurement results on the distribution of tsunami deposit with wave height and sand grain size. Therefore, in this study, hydraulic analysis of tsunami sediment formation process was examined based on the measurement data. Time series fluctuation of hydraulic parameters such as Froude number, Shields number, Rouse number etc. was calculated to understand on the formation process of tsunami deposit. In the front part of the tsunami, the flow velocity take strong flow from shoreline to around the middle of slope. From the measurement result in this time, it is considered that the dominant process of deposit formation is suspended state. At the run-up limit where the flow velocity decreases, the sediment moves in bedload state. As a result, the amount of sediment transport near the run-up limit changes under the influence of particle size.

J-SHIS - an integrated system for knowing seismic hazard information in Japan

NASA Astrophysics Data System (ADS)

Azuma, H.; Fujiwara, H.; Kawai, S.; Hao, K. X.; Morikawa, N.

2015-12-01

An integrated system of Japan seismic hazard information station (J-SHIS) was established in 2005 for issuing and exchanging information of the National Seismic Hazard Maps for Japan that are based on seismic hazard assessment (SHA). A simplified app, also named J-SHIS, for smartphones is popularly used in Japan based on the integrated system of http://www.j-shis.bosai.go.jp/map/?lang=en. "Smartphone tells hazard" is realized on a cellphone, a tablet and/or a PC. At a given spot, the comprehensive information of SHA map can be easily obtained as below: 1) A SHA probability at given intensity (JMA=5-, 5+, 6-, 6+) within 30 years. 2) A site amplification factor varies within 0.5 ~ 3.0 and expectation is 1 based on surface geology map information. 3) A depth of seismic basement down to ~3,000m based on deeper borehole and geological structure. 4) Scenario earthquake maps: By choosing an active fault, one got the average case for different parameters of the modeling. Then choose a case, you got the shaking map of intensity with color scale. "Seismic Hazard Karte tells more hazard" is another app based on website of http://www.j-shis.bosai.go.jp/labs/karte/. (1) For every mesh of 250m x 250m, professional service SHA information is provided over national-world. (2) With five ranks for eight items, comprehensive SHA information could be delivered. (3) Site amplification factor with an average index is given. (4) Deeper geologic structure modeling is provided with borehole profiling. (5) A SHA probability is assessed within 30 and/or 50 years for the given site. (6) Seismic Hazard curves are given for earthquake sources from inland active fault, subduction zone, undetermined and their summarization. (7) The JMA seismic intensities are assessed in long-term averaged periods of 500-years to ~100,000 years. The app of J-SHIS can be downloaded freely from http://www.j-shis.bosai.go.jp/app-jshis.

Peru 2007 tsunami runup observations and modeling

NASA Astrophysics Data System (ADS)

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.

A culture of tsunami preparedness and applying knowledge from recent tsunamis affecting California

NASA Astrophysics Data System (ADS)

Miller, K. M.; Wilson, R. I.

2012-12-01

It is the mission of the California Tsunami Program to ensure public safety by protecting lives and property before, during, and after a potentially destructive or damaging tsunami. In order to achieve this goal, the state has sought first to use finite funding resources to identify and quantify the tsunami hazard using the best available scientific expertise, modeling, data, mapping, and methods at its disposal. Secondly, it has been vital to accurately inform the emergency response community of the nature of the threat by defining inundation zones prior to a tsunami event and leveraging technical expertise during ongoing tsunami alert notifications (specifically incoming wave heights, arrival times, and the dangers of strong currents). State scientists and emergency managers have been able to learn and apply both scientific and emergency response lessons from recent, distant-source tsunamis affecting coastal California (from Samoa in 2009, Chile in 2010, and Japan in 2011). Emergency managers must understand and plan in advance for specific actions and protocols for each alert notification level provided by the NOAA/NWS West Coast/Alaska Tsunami Warning Center. Finally the state program has provided education and outreach information via a multitude of delivery methods, activities, and end products while keeping the message simple, consistent, and focused. The goal is a culture of preparedness and understanding of what to do in the face of a tsunami by residents, visitors, and responsible government officials. We provide an update of results and findings made by the state program with support of the National Tsunami Hazard Mitigation Program through important collaboration with other U.S. States, Territories and agencies. In 2009 the California Emergency Management Agency (CalEMA) and the California Geological Survey (CGS) completed tsunami inundation modeling and mapping for all low-lying, populated coastal areas of California to assist local jurisdictions on the coast in the identification of areas possible to be inundated in a tsunami. "Tsunami Inundation Maps for Emergency Planning" have provided the basis for some of the following preparedness, planning, and education activities in California: Improved evacuation and emergency response plans; Production of multi-language brochures: statewide, community, and boating; Development and support of tsunami scenario-driven exercises and drills; Development of workshops to educate both emergency managers and public; and Establishment of a comprehensive information website www.tsunami.ca.gov; and a preparedness website myhazards.calema.ca.gov. In addition, the California Tsunami Program has a number of initiatives underway through existing work plans to continue to apply scientifically vetted information toward comprehensive public understanding of the threat from future tsunamis to constituents on the coast. These include projects to: Complete tsunami land-use planning maps for California communities, Develop in-harbor tsunami hazard maps statewide, Complete modeling of offshore safety zones for the maritime community, Complete preliminary tsunami risk analysis for state utilizing new HAZUS tsunami module and probabilistic analysis results, and Develop a post-tsunami recovery and resiliency plan for the state.

Elders recall an earlier tsunami on Indian Ocean shores

USGS Publications Warehouse

Kakar, Din Mohammad; Naeem, Ghazala; Usman, Abdullah; Hasan, Haider; Lohdi, Hira; Srinivasalu, Seshachalam; Andrade, Vanessa; Rajendran, C.P.; Naderi Beni, Abdolmajid; Hamzeh, Mohammad Ali; Hoffmann, Goesta; Al Balushi, Noora; Gale, Nora; Kodijat, Ardito; Fritz, Hermann M.; Atwater, Brian F.

2014-01-01

Ten years on, the Indian Ocean tsunami of 26 December 2004 still looms large in efforts to reduce coastal risk. The disaster has spurred worldwide advances in tsunami detection and warning, tsunami-risk assessment, and tsunami awareness [Satake, 2014]. Nearly a lifetime has passed since the northwestern Indian Ocean last produced a devastating tsunami. Documentation of this tsunami, in November 1945, was hindered by international instability in the wake of the Second World War and, in British India, by the approach of independence and partition. The parent earthquake, of magnitude 8.1, was widely recorded, and the tsunami registered on tide gauges, but intelligence reports and newspaper articles say little about inundation limits while permitting a broad range of catalogued death tolls. What has been established about the 1945 tsunami falls short of what's needed today for ground-truthing inundation models, estimating risk to enlarged populations, and anchoring awareness campaigns in local facts. Recent efforts to reduce coastal risk around the Arabian Sea include a project in which eyewitnesses to the 1945 tsunami were found and interviewed (Fig. 1), and related archives were gathered. Results are being made available through UNESCO's Indian Ocean Tsunami Information Center in hopes of increasing scientific understanding and public awareness of the region's tsunami hazards.

Heavy minerals in the 2011 Tohoku-oki tsunami deposits—insights into sediment sources and hydrodynamics

NASA Astrophysics Data System (ADS)

Jagodziński, Robert; Sternal, Beata; Szczuciński, Witold; Chagué-Goff, Catherine; Sugawara, Daisuke

2012-12-01

The 2011 Tohoku-oki tsunami left sand and mud deposits more than 4 km inland on the coastal plain of Sendai, Japan. The tsunami deposits, pre-tsunami soils and beach sediments were analysed for grain size, and heavy mineral content and assemblages to test the applicability of heavy mineral analyses in the identification of tsunami deposits and interpretation of associated sedimentation processes. Heavy minerals comprised on average 35% of the tsunami deposit in the 0.125-0.25 mm grain size fraction. The most common were orthopyroxenes, clinopyroxenes, amphiboles, limonites and opaque minerals. Heavy mineral concentrations and assemblages were similar in the tsunami deposits, beach and pre-tsunami soils and sediments and thus tsunami deposits could not simply be identified based on their heavy minerals. Sediment provenance analysis revealed that tsunami deposits left within 1.5 km of the shoreline were mostly eroded from the beach, dune and local soils, while deposits farther inland (> 1.5 km) were mostly derived from local soil erosion. No evidence was found for a significant contribution of offshore sediments. Detailed analyses revealed that the lowermost portion of tsunami deposits was mostly of local origin, while the sediment source of the upper portion was variable. A comparison with a previous study of heavy minerals in 2004 IOT deposits confirms that heavy minerals in tsunami deposits are mostly source-dependent and may represent a useful supplementary tool in studies of tsunami deposits. However, the interpretation must always be placed in the local geological context and corroborated with other "tsunami proxies".

Solomon Islands 2007 Tsunami Near-Field Modeling and Source Earthquake Deformation

NASA Astrophysics Data System (ADS)

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, as well as event and post-event planning in the Solomon Islands.

Development, testing, and applications of site-specific tsunami inundation models for real-time forecasting

NASA Astrophysics Data System (ADS)

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 also demonstrates the nonlinearity between offshore and nearshore maximum wave amplitudes.

Global Tsunami Database: Adding Geologic Deposits, Proxies, and Tools

NASA Astrophysics Data System (ADS)

Brocko, V. R.; Varner, J.

2007-12-01

A result of collaboration between NOAA's National Geophysical Data Center (NGDC) and the Cooperative Institute for Research in the Environmental Sciences (CIRES), the Global Tsunami Database includes instrumental records, human observations, and now, information inferred from the geologic record. Deep Ocean Assessment and Reporting of Tsunamis (DART) data, historical reports, and information gleaned from published tsunami deposit research build a multi-faceted view of tsunami hazards and their history around the world. Tsunami history provides clues to what might happen in the future, including frequency of occurrence and maximum wave heights. However, instrumental and written records commonly span too little time to reveal the full range of a region's tsunami hazard. The sedimentary deposits of tsunamis, identified with the aid of modern analogs, increasingly complement instrumental and human observations. By adding the component of tsunamis inferred from the geologic record, the Global Tsunami Database extends the record of tsunamis backward in time. Deposit locations, their estimated age and descriptions of the deposits themselves fill in the tsunami record. Tsunamis inferred from proxies, such as evidence for coseismic subsidence, are included to estimate recurrence intervals, but are flagged to highlight the absence of a physical deposit. Authors may submit their own descriptions and upload digital versions of publications. Users may sort by any populated field, including event, location, region, age of deposit, author, publication type (extract information from peer reviewed publications only, if you wish), grain size, composition, presence/absence of plant material. Users may find tsunami deposit references for a given location, event or author; search for particular properties of tsunami deposits; and even identify potential collaborators. Users may also download public-domain documents. Data and information may be viewed using tools designed to extract and display data from the Oracle database (selection forms, Web Map Services, and Web Feature Services). In addition, the historic tsunami archive (along with related earthquakes and volcanic eruptions) is available in KML (Keyhole Markup Language) format for use with Google Earth and similar geo-viewers.

Improvement of tsunami detection in timeseries data of GPS buoys with the Continuous Wavelet Transform

NASA Astrophysics Data System (ADS)

Chida, Y.; Takagawa, T.

2017-12-01

The observation data of GPS buoys which are installed in the offshore of Japan are used for monitoring not only waves but also tsunamis in Japan. The real-time data was successfully used to upgrade the tsunami warnings just after the 2011 Tohoku earthquake. Huge tsunamis can be easily detected because the signal-noise ratio is high enough, but moderate tsunami is not. GPS data sometimes include the error waveforms like tsunamis because of changing accuracy by the number and the position of GPS satellites. To distinguish the true tsunami waveforms from pseudo-tsunami ones is important for tsunami detection. In this research, a method to reduce misdetections of tsunami in the observation data of GPS buoys and to increase the efficiency of tsunami detection was developed.Firstly, the error waveforms were extracted by using the indexes of position dilution of precision, reliability of GPS satellite positioning and satellite number for calculation. Then, the output from this procedure was used for the Continuous Wavelet Transform (CWT) to analyze the time-frequency characteristics of error waveforms and real tsunami waveforms.We found that the error waveforms tended to appear when the accuracy of GPS buoys positioning was low. By extracting these waveforms, it was possible to decrease about 43% error waveforms without the reduction of the tsunami detection rate. Moreover, we found that the amplitudes of power spectra obtained from the error waveforms and real tsunamis were similar in the component of long period (4-65 minutes), on the other hand, the amplitude in the component of short period (< 1 minute) obtained from the error waveforms was significantly larger than that of the real tsunami waveforms. By thresholding of the short-period component, further extraction of error waveforms became possible without a significant reduction of tsunami detection rate.

What Causes Tsunamis?

ERIC Educational Resources Information Center

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…

Tsunami Preparedness in California (videos)

USGS Publications Warehouse

Filmed and edited by: Loeffler, Kurt; Gesell, Justine

2010-01-01

Tsunamis are a constant threat to the coasts of our world. Although tsunamis are infrequent along the West coast of the United States, it is possible and necessary to prepare for potential tsunami hazards to minimize loss of life and property. Community awareness programs are important, as they strive to create an informed society by providing education and training. These videos about tsunami preparedness in California distinguish between a local tsunami and a distant event and focus on the specific needs of each region. They offer guidelines for correct tsunami response and community preparedness from local emergency managers, first-responders, and leading experts on tsunami hazards and warnings, who have been working on ways of making the tsunami affected regions safer for the people and communities on a long-term basis. These videos were produced by the U.S. Geological Survey (USGS) in cooperation with the California Emergency Management Agency (CalEMA) and Pacific Gas and Electric Company (PG&E).

Tsunami Preparedness in Oregon (video)

USGS Publications Warehouse

Filmed and edited by: Loeffler, Kurt; Gesell, Justine

2010-01-01

Tsunamis are a constant threat to the coasts of our world. Although tsunamis are infrequent along the West coast of the United States, it is possible and necessary to prepare for potential tsunami hazards to minimize loss of life and property. Community awareness programs are important, as they strive to create an informed society by providing education and training. This video about tsunami preparedness in Oregon distinguishes between a local tsunami and a distant event and focus on the specific needs of this region. It offers guidelines for correct tsunami response and community preparedness from local emergency managers, first-responders, and leading experts on tsunami hazards and warnings, who have been working on ways of making the tsunami affected regions safer for the people and communities on a long-term basis. This video was produced by the US Geological Survey (USGS) in cooperation with Oregon Department of Geology and Mineral Industries (DOGAMI).

The 15 August 2007 Peru tsunami runup observations and modeling

NASA Astrophysics Data System (ADS)

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.

Mechanism of the 2015 volcanic tsunami earthquake near Torishima, Japan

PubMed Central

Satake, Kenji

2018-01-01

Tsunami earthquakes are a group of enigmatic earthquakes generating disproportionally large tsunamis relative to seismic magnitude. These events occur most typically near deep-sea trenches. Tsunami earthquakes occurring approximately every 10 years near Torishima on the Izu-Bonin arc are another example. Seismic and tsunami waves from the 2015 event [Mw (moment magnitude) = 5.7] were recorded by an offshore seafloor array of 10 pressure gauges, ~100 km away from the epicenter. We made an array analysis of dispersive tsunamis to locate the tsunami source within the submarine Smith Caldera. The tsunami simulation from a large caldera-floor uplift of ~1.5 m with a small peripheral depression yielded waveforms remarkably similar to the observations. The estimated central uplift, 1.5 m, is ~20 times larger than that inferred from the seismologically determined non–double-couple source. Thus, the tsunami observation is not compatible with the published seismic source model taken at face value. However, given the indeterminacy of Mzx, Mzy, and M{tensile} of a shallow moment tensor source, it may be possible to find a source mechanism with efficient tsunami but inefficient seismic radiation that can satisfactorily explain both the tsunami and seismic observations, but this question remains unresolved. PMID:29740604

Mechanism of the 2015 volcanic tsunami earthquake near Torishima, Japan.

PubMed

Fukao, Yoshio; Sandanbata, Osamu; Sugioka, Hiroko; Ito, Aki; Shiobara, Hajime; Watada, Shingo; Satake, Kenji

2018-04-01

Tsunami earthquakes are a group of enigmatic earthquakes generating disproportionally large tsunamis relative to seismic magnitude. These events occur most typically near deep-sea trenches. Tsunami earthquakes occurring approximately every 10 years near Torishima on the Izu-Bonin arc are another example. Seismic and tsunami waves from the 2015 event [ M w (moment magnitude) = 5.7] were recorded by an offshore seafloor array of 10 pressure gauges, ~100 km away from the epicenter. We made an array analysis of dispersive tsunamis to locate the tsunami source within the submarine Smith Caldera. The tsunami simulation from a large caldera-floor uplift of ~1.5 m with a small peripheral depression yielded waveforms remarkably similar to the observations. The estimated central uplift, 1.5 m, is ~20 times larger than that inferred from the seismologically determined non-double-couple source. Thus, the tsunami observation is not compatible with the published seismic source model taken at face value. However, given the indeterminacy of M zx , M zy , and M {tensile} of a shallow moment tensor source, it may be possible to find a source mechanism with efficient tsunami but inefficient seismic radiation that can satisfactorily explain both the tsunami and seismic observations, but this question remains unresolved.

Immediate Ecological Impacts of the 2011 Tohoku Earthquake Tsunami on Intertidal Flat Communities

PubMed Central

Urabe, Jotaro; Suzuki, Takao; Nishita, Tatsuki; Makino, Wataru

2013-01-01

Following the Great East Japan Earthquake in 2011, a large tsunami developed and struck the Pacific coast of eastern Japan. To assess the immediate impacts of the tsunami on coastal communities, changes in taxon composition and richness of macrobenthic animals before and after the tsunami were examined at nine intertidal flats in Sendai Bay and the Sanriku Ria coast. The results showed that 30–80% of taxa indigenously inhabiting intertidal flats disappeared after the tsunami. Among animal types, endobenthic and sessile epibenthic animals were more vulnerable to the tsunami than mobile epibenthic animals like shore crabs and snails. For all the intertidal flats examined, animals that were originally dwellers in lower tidal zones and not recorded before the tsunami were also found right after the tsunami, indicating that the tsunami not only took away many benthic taxa from the intertidal flats but also brought in some taxa from elsewhere. However, overall changes in taxon community composition were greater for intertidal flats that experienced larger inundation heights. These results showed that the ecological impacts of the tsunami were proportional to the physical impacts as gauged by wave height and that mobile epibenthic animals were less vulnerable to the tsunami. PMID:23650529

Immediate ecological impacts of the 2011 Tohoku earthquake tsunami on intertidal flat communities.

PubMed

Urabe, Jotaro; Suzuki, Takao; Nishita, Tatsuki; Makino, Wataru

2013-01-01

Following the Great East Japan Earthquake in 2011, a large tsunami developed and struck the Pacific coast of eastern Japan. To assess the immediate impacts of the tsunami on coastal communities, changes in taxon composition and richness of macrobenthic animals before and after the tsunami were examined at nine intertidal flats in Sendai Bay and the Sanriku Ria coast. The results showed that 30-80% of taxa indigenously inhabiting intertidal flats disappeared after the tsunami. Among animal types, endobenthic and sessile epibenthic animals were more vulnerable to the tsunami than mobile epibenthic animals like shore crabs and snails. For all the intertidal flats examined, animals that were originally dwellers in lower tidal zones and not recorded before the tsunami were also found right after the tsunami, indicating that the tsunami not only took away many benthic taxa from the intertidal flats but also brought in some taxa from elsewhere. However, overall changes in taxon community composition were greater for intertidal flats that experienced larger inundation heights. These results showed that the ecological impacts of the tsunami were proportional to the physical impacts as gauged by wave height and that mobile epibenthic animals were less vulnerable to the tsunami.

Assessment of a Tsunami Hazard for Mediterranean Coast of Egypt

NASA Astrophysics Data System (ADS)

Zaytsev, Andrey; Babeyko, Andrey; Yalciner, Ahmet; Pelinovsky, Efim

2017-04-01

Analysis of tsunami hazard for Egypt based on historic data and numerical modelling of historic and prognostic events is given. There are 13 historic events for 4000 years, including one instrumental record (1956). Tsunami database includes 12 earthquake tsunamis and 1 event of volcanic origin (Santorini eruption). Tsunami intensity of events (365, 881, 1303, 1870) is estimated as I = 3 led to tsunami wave height more than 6 m. Numerical simulation of some possible scenario of tsunamis of seismic and landslide origin is done with use of NAMI-DANCE software solved the shallow-water equations. The PTHA method (Probabilistic Tsunami Hazard Assessment - Probabilistic assessment of a tsunami hazard) for the Mediterranean Sea developed in (Sorensen M.B., Spada M., Babeyko A., Wiemer S., Grunthal G. Probabilistic tsunami hazard in the Mediterranean Sea. J Geophysical Research, 2012, vol. 117, B01305) is used to evaluate the probability of tsunami occurrence on the Egyptian coast. The synthetic catalogue of prognostic tsunamis of seismic origin with magnitude more than 6.5 includes 84 920 events for 100000 years. For the wave heights more 1 m the curve: exceedance probability - tsunami height can be approximated by exponential Gumbel function with two parameters which are determined for each coastal location in Egypt (totally. 24 points). Prognostic extreme highest events with probability less 10-4 are not satisfied to the Gumbel function (approximately 10 events) and required the special analysis. Acknowledgements: This work was supported EU FP7 ASTARTE Project [603839], and for EP - NS6637.2016.5.

New Measurements and Modeling Capability to Improve Real-time Forecast of Cascadia Tsunamis along U.S. West Coast

NASA Astrophysics Data System (ADS)

Wei, Y.; Titov, V. V.; Bernard, E. N.; Spillane, M. C.

2014-12-01

The tragedies of 2004 Sumatra and 2011 Tohoku tsunamis exposed the limits of our knowledge in preparing for devastating tsunamis, especially in the near field. The 1,100-km coastline of the Pacific coast of North America has tectonic and geological settings similar to Sumatra and Japan. The geological records unambiguously show that the Cascadia fault had caused devastating tsunamis in the past and this geological process will cause tsunamis in the future. Existing observational instruments along the Cascadia Subduction Zone are capable of providing tsunami data within minutes of tsunami generation. However, this strategy requires separation of the tsunami signals from the overwhelming high-frequency seismic waves produced during a strong earthquake- a real technical challenge for existing operational tsunami observational network. A new-generation of nano-resolution pressure sensors can provide high temporal resolution of the earthquake and tsunami signals without loosing precision. The nano-resolution pressure sensor offers a state-of the-science ability to separate earthquake vibrations and other oceanic noise from tsunami waveforms, paving the way for accurate, early warnings of local tsunamis. This breakthrough underwater technology has been tested and verified for a couple of micro-tsunami events (Paros et al., 2011). Real-time forecast of Cascadia tsunamis is becoming a possibility with the development of nano-tsunameter technology. The present study provides an investigation on optimizing the placement of these new sensors so that the forecast time can be shortened.. The presentation will cover the optimization of an observational array to quickly detect and forecast a tsunami generated by a strong Cascadia earthquake, including short and long rupture scenarios. Lessons learned from the 2011 Tohoku tsunami will be examined to demonstrate how we can improve the local forecast using the new technology We expect this study to provide useful guideline for future siting and deployment of the new-generation tsunameters. Driven by the new technology, we demonstrate scenarios of real-time forecast of Cascadia tsunami impact along the Pacific Northwest, as well as in the Puget Sound.

Multiple indices method for real-time tsunami inundation forecast using a dense offshore observation network

NASA Astrophysics Data System (ADS)

Yamamoto, N.; Aoi, S.; Hirata, K.; Suzuki, W.; Kunugi, T.; Nakamura, H.

2015-12-01

We started to develop a new methodology for real-time tsunami inundation forecast system (Aoi et al., 2015, this meeting) using densely offshore tsunami observations of the Seafloor Observation Network for Earthquakes and Tsunamis (S-net), which is under construction along the Japan Trench (Kanazawa et al., 2012, JpGU; Uehira et al., 2015, IUGG). In our method, the most important concept is involving any type and/or form uncertainties in the tsunami forecast, which cannot be dealt with any of standard linear/nonlinear least square approaches. We first prepare a Tsunami Scenario Bank (TSB), which contains offshore tsunami waveforms at the S-net stations and tsunami inundation information calculated from any possible tsunami source. We then quickly select several acceptable tsunami scenarios that can explain offshore observations by using multiple indices and appropriate thresholds, after a tsunami occurrence. At that time, possible tsunami inundations coupled with selected scenarios are forecasted (Yamamoto et al., 2014, AGU). Currently, we define three indices: correlation coefficient and two variance reductions, whose L2-norm part is normalized either by observations or calculations (Suzuki et al., 2015, JpGU; Yamamoto et al., 2015, IUGG). In this study, we construct the TSB, which contains various tsunami source models prepared for the probabilistic tsunami hazard assessment in the Japan Trench region (Hirata et al., 2014, AGU). To evaluate the propriety of our method, we adopt the fault model based on the 2011 Tohoku earthquake as a pseudo "observation". We also calculate three indices using coastal maximum tsunami height distributions between observation and calculation. We then obtain the correlation between coastal and offshore indices. We notice that the index value of coastal maximum tsunami heights is closer to 1 than the index value of offshore waveforms, i.e., the coastal maximum tsunami height may be predictable within appropriate thresholds defined for offshore indices. We also investigate the effect of rise-time. This work was partially supported by the Council for Science, Technology and Innovation (CSTI) through the Cross-ministerial Strategic Innovation Promotion Program (SIP), titled "Enhancement of societal resiliency against natural disasters" (Funding agency: JST).

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.

NASA Astrophysics Data System (ADS)

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.

First application of tsunami back-projection and source inversion for the 2012 Haida Gwaii earthquake using tsunami data recorded on a dense array of seafloor pressure gauges

NASA Astrophysics Data System (ADS)

Gusman, A. R.; Satake, K.; Sheehan, A. F.; Mulia, I. E.; Heidarzadeh, M.; Maeda, T.

2015-12-01

Adaption of absolute or differential pressure gauges (APG or DPG) to Ocean Bottom Seismometers has provided the opportunity to study tsunamis. Recently we extracted tsunami waveforms of the 28 October 2012 Haida Gwaii earthquake recoded by the APG and DPG of Cascadia Initiative program (Sheehan et al., 2015, SRL). We applied such dense tsunami observations (48 stations) together with other records from DARTs (9 stations) to characterize the tsunami source. This study is the first study that used such a large number of offshore tsunami records for earthquake source study. Conventionally the curves of tsunami travel times are drawn backward from station locations to estimate the tsunami source region. Here we propose a more advanced technique called tsunami back-projection to estimate the source region. Our image produced by tsunami back-projection has the largest value or tsunami centroid that is very close to the epicenter and above the Queen Charlotte transform fault (QCF), whereas the negative values are mostly located east of Haida Gwaii in the Hecate Strait. By using tsunami back-projection we avoid picking initial tsunami phase which is a necessary step in the conventional method that is rather subjective. The slip distribution of the 2012 Haida Gwaii earthquake estimated by tsunami waveform inversion shows large slip near the trench (4-5 m) and also on a plate interface southeast the epicenter (3-4 m) below QCF. From the slip distribution, the calculated seismic moment is 5.4 × 1020 N m (Mw 7.8). The steep bathymetry offshore Haida Gwaii and the horizontal movement caused by the earthquake possibly affects the sea surface deformation. The potential tsunami energy calculated from the sea-surface deformation of pure faulting is 2.20 × 1013 J, while that from the bathymetry effect is 0.12 × 1013 J or about 5% of the total potential energy. The significant deformation above the steep slope is confirmed by another tsunami inversion that disregards fault parameters.

Non-Poissonian Distribution of Tsunami Waiting Times

NASA Astrophysics Data System (ADS)

Geist, E. L.; Parsons, T.

2007-12-01

Analysis of the global tsunami catalog indicates that tsunami waiting times deviate from an exponential distribution one would expect from a Poisson process. Empirical density distributions of tsunami waiting times were determined using both global tsunami origin times and tsunami arrival times at a particular site with a sufficient catalog: Hilo, Hawai'i. Most sources for the tsunamis in the catalog are earthquakes; other sources include landslides and volcanogenic processes. Both datasets indicate an over-abundance of short waiting times in comparison to an exponential distribution. Two types of probability models are investigated to explain this observation. Model (1) is a universal scaling law that describes long-term clustering of sources with a gamma distribution. The shape parameter (γ) for the global tsunami distribution is similar to that of the global earthquake catalog γ=0.63-0.67 [Corral, 2004]. For the Hilo catalog, γ is slightly greater (0.75-0.82) and closer to an exponential distribution. This is explained by the fact that tsunamis from smaller triggered earthquakes or landslides are less likely to be recorded at a far-field station such as Hilo in comparison to the global catalog, which includes a greater proportion of local tsunamis. Model (2) is based on two distributions derived from Omori's law for the temporal decay of triggered sources (aftershocks). The first is the ETAS distribution derived by Saichev and Sornette [2007], which is shown to fit the distribution of observed tsunami waiting times. The second is a simpler two-parameter distribution that is the exponential distribution augmented by a linear decay in aftershocks multiplied by a time constant Ta. Examination of the sources associated with short tsunami waiting times indicate that triggered events include both earthquake and landslide tsunamis that begin in the vicinity of the primary source. Triggered seismogenic tsunamis do not necessarily originate from the same fault zone, however. For example, subduction-thrust and outer-rise earthquake pairs are evident, such as the November 2006 and January 2007 Kuril Islands tsunamigenic pair. Because of variations in tsunami source parameters, such as water depth above the source, triggered tsunami events with short waiting times are not systematically smaller than the primary tsunami.

Assessment of tsunami resilience of Haydarpaşa Port in the Sea of Marmara by high-resolution numerical modeling

NASA Astrophysics Data System (ADS)

Aytore, Betul; Yalciner, Ahmet Cevdet; Zaytsev, Andrey; Cankaya, Zeynep Ceren; Suzen, Mehmet Lütfi

2016-08-01

Turkey is highly prone to earthquakes because of active fault zones in the region. The Marmara region located at the western extension of the North Anatolian Fault Zone (NAFZ) is one of the most tectonically active zones in Turkey. Numerous catastrophic events such as earthquakes or earthquake/landslide-induced tsunamis have occurred in the Marmara Sea basin. According to studies on the past tsunami records, the Marmara coasts have been hit by 35 different tsunami events in the last 2000 years. The recent occurrences of catastrophic tsunamis in the world's oceans have also raised awareness about tsunamis that might take place around the Marmara coasts. Similarly, comprehensive studies on tsunamis, such as preparation of tsunami databases, tsunami hazard analysis and assessments, risk evaluations for the potential tsunami-prone regions, and establishing warning systems have accelerated. However, a complete tsunami inundation analysis in high resolution will provide a better understanding of the effects of tsunamis on a specific critical structure located in the Marmara Sea. Ports are one of those critical structures that are susceptible to marine disasters. Resilience of ports and harbors against tsunamis are essential for proper, efficient, and successful rescue operations to reduce loss of life and property. Considering this, high-resolution simulations have been carried out in the Marmara Sea by focusing on Haydarpaşa Port of the megacity Istanbul. In the first stage of simulations, the most critical tsunami sources possibly effective for Haydarpaşa Port were inputted, and the computed tsunami parameters at the port were compared to determine the most critical tsunami scenario. In the second stage of simulations, the nested domains from 90 m gird size to 10 m grid size (in the port region) were used, and the most critical tsunami scenario was modeled. In the third stage of simulations, the topography of the port and its regions were used in the two nested domains in 3-m and 1-m resolutions and the water elevations computed from the previous simulations were inputted from the border of the large domain. A tsunami numerical code, NAMI DANCE, was used in the simulations. The tsunami parameters in the highest resolution were computed in and around the port. The effect of the data resolution on the computed results has been presented. The performance of the port structures and possible effects of tsunami on port operations have been discussed. Since the harbor protection structures have not been designed to withstand tsunamis, the breakwaters' stability becomes one of the major concerns for less agitation and inundation under tsunami in Haydarpaşa Port for resilience. The flow depth, momentum fluxes, and current pattern are the other concerns that cause unexpected circulations and uncontrolled movements of objects on land and vessels in the sea.

The search for geologic evidence of distant-source tsunamis using new field data in California: Chapter C in The SAFRR (Science Application for Risk Reduction) Tsunami Scenario

USGS Publications Warehouse

Wilson, Rick; Hemphill-Haley, Eileen; Jaffe, Bruce; Richmond, Bruce; Peters, Robert; Graehl, Nick; Kelsey, Harvey; Leeper, Robert; Watt, Steve; McGann, Mary; Hoirup, Don F.; Chagué-Goff, Catherine; Goff, James; Caldwell, Dylan; Loofbourrow, Casey

2014-01-01

A statewide assessment for geological evidence of tsunamis, primarily from distant-source events, found tsunami deposits at several locations, though evidence was absent at most locations evaluated. Several historical distant-source tsunamis, including the 1946 Aleutian, 1960 Chile, and 1964 Alaska events, caused inundation along portions of the northern and central California coast. Recent numerical tsunami modeling results identify the eastern Aleutian Islands subduction zone as the “worstcase” distant-source region, with the potential for causing tsunami runups of 7–10 m in northern and central California and 3–4 m in southern California. These model results, along with a review of historical topographic maps and past geotechnical evaluations, guided site selection for tsunami deposit surveys. A reconnaissance of 20 coastal marshlands was performed through site visits and coring of shallow surface sediments to determine if evidence for past tsunamis existed. Although conclusive evidence of tsunami deposits was not found at most of the sites evaluated, geologic evidence consistent with tsunami inundation was found at two locations: Three marshes in the Crescent City area and Pillar Point marsh near Half Moon Bay. Potential tsunami deposits were also evaluated at the Carpinteria Salt Marsh Reserve in Santa Barbara County. In Crescent City, deposits were ascribed to tsunamis on the basis of stratigraphic architecture, particle size, and microfossil content, and they were further assigned to the 1964 Alaska and 1700 Cascadia tsunamis on the basis of dating by cesium-137 and radiocarbon methods, respectively. The 1946 tsunami sand deposit was clearly identified throughout Pillar Point marsh, and one to two other similar but highly discontinuous sand layers were present within 0.5 m of the surface. A tsunami-origin interpretation for sand layers at Carpinteria is merely consistent with graded bedding and unsupported by diatom or foraminiferal assemblages. Additional studies, including age dating, grain-size, and microfossil analyses are underway for the deposits at Crescent City, Pillar Point marsh, and Carpinteria, which may help further identify if other tsunami deposits exist at those sites. The absence of evidence for tsunamis at other sites examined should not preclude further work beyond the reconnaissance-level investigations at those locations.

Evaluation of tsunami risk in Heraklion city, Crete, Greece, by using GIS methods

NASA Astrophysics Data System (ADS)

Triantafyllou, Ioanna; Fokaefs, Anna; Novikova, Tatyana; Papadopoulos, Gerasimos A.; Vaitis, Michalis

2016-04-01

The Hellenic Arc is the most active seismotectonic structure in the Mediterranean region. The island of Crete occupies the central segment of the arc which is characterized by high seismic and tsunami activity. Several tsunamis generated by large earthquakes, volcanic eruptions and landslides were reported that hit the capital city of Heraklion in the historical past. We focus our tsunami risk study in the northern coastal area of Crete (ca. 6 km in length and 1 km in maximum width) which includes the western part of the city of Heraklion and a large part of the neighboring municipality of Gazi. The evaluation of tsunami risk included calculations and mapping with QGIS of (1) cost for repairing buildings after tsunami damage, (2) population exposed to tsunami attack, (3) optimum routes and times for evacuation. To calculate the cost for building reparation after a tsunami attack we have determined the tsunami inundation zone in the study area after numerical simulations for extreme tsunami scenarios. The geographical distribution of buildings per building block, obtained from the 2011 census data of the Hellenic Statistical Authority (EL.STAT) and satellite data, was mapped. By applying the SCHEMA Damage Tool we assessed the building vulnerability to tsunamis according to the types of buildings and their expected damage from the hydrodynamic impact. A set of official cost rates varying with the building types and the damage levels, following standards set by the state after the strong damaging earthquakes in Greece in 2014, was applied to calculate the cost of rebuilding or repairing buildings damaged by the tsunami. In the investigation of the population exposed to tsunami inundation we have used the interpolation method to smooth out the population geographical distribution per building block within the inundation zone. Then, the population distribution was correlated with tsunami hydrodynamic parameters in the inundation zone. The last approach of tsunami risk assessment refers to the selection of optimal routes and times needed for evacuation from certain points within the inundation zone to a number of shelters outside the zone. The three different approaches were evaluated as for their overall contribution in the development of a plan for the tsunami risk mitigation. This research is a contribution to the EU-FP7 tsunami research project ASTARTE (Assessment, Strategy And Risk Reduction for Tsunamis in Europe), grant agreement no: 603839, 2013-10-30.

Lingering effects of preceding strong El Niño events on the typhoon activity in early summer: Case study of sub-seasonal and seasonal predictions in 2016

NASA Astrophysics Data System (ADS)

Takaya, Y.; Kubo, Y.; Yamaguchi, M.; Vitart, F.; Hirahara, S.; Maeda, S.

2016-12-01

Strong El Niño events have lingering effects on the seasonal variability in the Indo- western Pacific region in the mature-decay phase of El Niño. Specifically, in the decay phase, a low-level anticyclonic circulation and suppressed convection in the western North Pacific are enforced as a result of a local air-sea feedback in the western North Pacific and remote response to the Indian Ocean warming due to El Niño. The typhoon activity in the western North Pacific is also modulated by the lingering effects in the early typhoon season (boreal spring to early summer) following the strong El Niño events. This study investigates underlying mechanisms and predictability by analyzing the historical analysis data, subseasonal and seasonal reforecast data, and sensitivity experiments with the use of an atmosphere-ocean coupled model for the 2016 typhoon season. In this study, we focus on the remote response of the typhoon activity in the Indo-Pacific region. First, we examined the case of 2016, which exhibited the striking inactive typhoon activity and marked the second latest genesis of the first typhoon of the year since 1977 (Typhoon Nipartak on 3 July 2016). The inactive typhoon activity in the early typhoon season of 2016 is plausibly related to the lingering effects of the preceding strong El Niño in 2015/2016 winter. And the inactive typhoon condition and its related atmosphere-ocean conditions in the western north Pacific were successfully predicted with sub-seasonal prediction systems and JMA seasonal prediction system (JMA/MRI-CPS2) well in advance. A composite analysis using historical analysis data indicates that the typhoon activity tends to be suppressed associated with the Indian Ocean warming in boreal spring to summer following El Niño winters. This is relatively well replicated in reforecasts of JMA/MRI-CPS2. We also carried out sensitivity experiments with JMA/MRI-CPS2, where we strongly nudge sea surface temperature (SST) in the Indian Ocean to climatological SST. The typhoon activity in the western North Pacific is enhanced in the sensitivity experiment, implying that the the Indian Ocean played a role in shaping the inactive typhoon conditions in the 2016 typhoon season. We will further discuss the underlying mechanisms and predictability using the series of experiments.

Using Interdisciplinary Research Methods to Revise and Strengthen the NWS TsunamiReadyTM Community Recognition Program

NASA Astrophysics Data System (ADS)

Scott, C.; Gregg, C. E.; Ritchie, L.; Stephen, M.; Farnham, C.; Fraser, S. A.; Gill, D.; Horan, J.; Houghton, B. F.; Johnson, V.; Johnston, D.

2013-12-01

The National Tsunami Hazard Mitigation Program (NTHMP) partnered with the National Weather Service (NWS) in early 2000 to create the TsunamiReadyTM Community Recognition program. TsunamiReadyTM, modeled after the older NWS StormReadyTM program, is designed to help cities, towns, counties, universities and other large sites in coastal areas reduce the potential for disastrous tsunami-related consequences. To achieve TsunamiReadyTM recognition, communities must meet certain criteria aimed at better preparing a community for tsunami, including specific actions within the following categories: communications and coordination, tsunami warning reception, local warning dissemination, community preparedness, and administration. Using multidisciplinary research methods and strategies from Public Health; Psychology; Political, Social and Physical Sciences and Evaluation, our research team is working directly with a purposive sample of community stakeholders in collaboration and feedback focus group sessions. Invitation to participate is based on a variety of factors including but not limited to an individual's role as a formal or informal community leader (e.g., in business, government, civic organizations), or their organization or agency affiliation to emergency management and response. Community organizing and qualitative research methods are being used to elicit discussion regarding TsunamiReadyTM requirements and the division of requirements based on some aspect of tsunami hazard, vulnerability and risk, such as proximity to active or passive plate margins or subduction zone generated tsunamis versus earthquake-landslide generated tsunamis . The primary aim of this research is to use social science to revise and refine the NWS TsunamiReadyTM Guidelines in an effort to better prepare communities to reduce risk to tsunamis.

Tsunami magnetic signals in the Northwestern Pacific seafloor magnetic measurements

NASA Astrophysics Data System (ADS)

Schnepf, N. R.; An, C.; Nair, M. C.; Maus, S.

2013-12-01

In the past two decades, underwater cables and seafloor magnetometers have observed motional inductance from ocean tsunamis. This study aimed to characterize the electromagnetic signatures of tsunamis from seafloor stations to assist in the long-term goal of real-time tsunami detection and warning systems. Four ocean seafloor stations (T13, T14, T15, T18) in the Northeastern Philippine Sea collected vector measurements of the electric and magnetic fields every minute during the period of 10/05/2005 to 11/30/2007 (Baba et al., 2010 PEPI). During this time, four major tsunamis occurred as a result of moment magnitude 8.0-8.1 earthquakes. These tsunamis include the 05/03/2006 Tonga event, the 01/13/2007 Kuril Islands event, the 04/01/2007 Solomon Islands event, and the 08/15/2007 Peru event. The Cornell Multi-grid Coupled Tsunami model (COMCOT) was used to predict the arrival time of the tsunamis at each of the seafloor stations. The stations' raw magnetic field signals underwent a high pass filter to then be examined for signals of the tsunami arrival. The high pass filtering showed clear tsunami signals for the Tonga event, but a clear signal was not seen for the other events. This may be due to signals from near Earth space with periods similar to tsunamis. To remove extraneous atmospheric magnetic signals, a cross-wavelet analysis was conducted using the horizontal field components from three INTERMAGNET land stations and the vertical component from the seafloor stations. The cross-wavelet analysis showed that for three of the six stations (two of the four tsunami events) the peak in wavelet amplitude matched the arrival of the tsunami. We discuss implications of our finding in magnetic monitoring of tsunamis.

The UBO-TSUFD tsunami inundation model: validation and application to a tsunami case study focused on the city of Catania, Italy

NASA Astrophysics Data System (ADS)

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.

Tsunami Data and Scientific Data Diplomacy

NASA Astrophysics Data System (ADS)

Arcos, N. P.; Dunbar, P. K.; Gusiakov, V. K.; Kong, L. S. L.; Aliaga, B.; Yamamoto, M.; Stroker, K. J.

2016-12-01

Free and open access to data and information fosters scientific progress and can build bridges between nations even when political relationships are strained. Data and information held by one stakeholder may be vital for promoting research of another. As an emerging field of inquiry, data diplomacy explores how data-sharing helps create and support positive relationships between countries to enable the use of data for societal and humanitarian benefit. Tsunami has arguably been the only natural hazard that has been addressed so effectively at an international scale and illustrates the success of scientific data diplomacy. Tsunami mitigation requires international scientific cooperation in both tsunami science and technology development. This requires not only international agreements, but working-level relationships between scientists from countries that may have different political and economic policies. For example, following the Pacific wide tsunami of 1960 that killed two thousand people in Chile and then, up to a day later, hundreds in Hawaii, Japan, and the Philippines; delegates from twelve countries met to discuss and draft the requirements for an international tsunami warning system. The Pacific Tsunami Warning System led to the development of local, regional, and global tsunami databases and catalogs. For example, scientists at NOAA/NCEI and the Tsunami Laboratory/Russian Academy of Sciences have collaborated on their tsunami catalogs that are now routinely accessed by scientists and the public around the world. These data support decision-making during tsunami events, are used in developing inundation and evacuation maps, and hazard assessments. This presentation will include additional examples of agreements for data-sharing between countries, as well as challenges in standardization and consistency among the tsunami research community. Tsunami data and scientific data diplomacy have ultimately improved understanding of tsunami and associated impacts.

Deposition by the 2011 Tohoku-oki tsunami on coastal lowland controlled by beach ridges near Sendai, Japan

NASA Astrophysics Data System (ADS)

Takashimizu, Yasuhiro; Urabe, Atsushi; Suzuki, Koji; Sato, Yoshiki

2012-12-01

A study of the 2011 Tohoku-oki tsunami deposits on the coastal lowland of the Sendai Plain, Japan was carried out along a shore-perpendicular survey line in the Arahama area. Field descriptions and tsunami water depth measurements were complemented by sedimentary analyses, including grain size, grain fabric and diatom analysis. The tsunami deposits show a generally fining-inland trend along the 3.4 km long transect. The depositional facies, grain size analysis and grain fabric data suggest that most of the tsunami deposits were laid down during the tsunami inflow, except at one site. These tsunami deposits are characterized by parallel-laminated or massive sand and silt with pieces of woods, fragments of glass, rip-up mud clasts and an erosional base. Minor backwash deposits overlying the inflow sand layer were only observed on one beach ridge and attributed to the topographic high. Marine diatom species comprised only approximately 2% of the diatom assemblage in tsunami deposits and their content decreased landward. In this study, diatom assemblages were similar in the rice field soil and tsunami layers, suggesting that the muddy fraction of the deposits mainly consists of sediments derived from the tsunami-eroded rice field soil. As a result of soil erosion, the tsunami had a high suspended sediment load. Furthermore, after the first tsunami inundation, seawater left by the tsunami did not drain completely to the sea because of the high coastal beach ridge and/or coastal subsidence due to the massive earthquake. Therefore, strong tsunami outflows to the sea did not occur and these areas were covered by mud deposited from stagnant water.

Assessing historical rate changes in global tsunami occurrence

USGS Publications Warehouse

Geist, E.L.; Parsons, T.

2011-01-01

The global catalogue of tsunami events is examined to determine if transient variations in tsunami rates are consistent with a Poisson process commonly assumed for tsunami hazard assessments. The primary data analyzed are tsunamis with maximum sizes >1m. The record of these tsunamis appears to be complete since approximately 1890. A secondary data set of tsunamis >0.1m is also analyzed that appears to be complete since approximately 1960. Various kernel density estimates used to determine the rate distribution with time indicate a prominent rate change in global tsunamis during the mid-1990s. Less prominent rate changes occur in the early- and mid-20th century. To determine whether these rate fluctuations are anomalous, the distribution of annual event numbers for the tsunami catalogue is compared to Poisson and negative binomial distributions, the latter of which includes the effects of temporal clustering. Compared to a Poisson distribution, the negative binomial distribution model provides a consistent fit to tsunami event numbers for the >1m data set, but the Poisson null hypothesis cannot be falsified for the shorter duration >0.1m data set. Temporal clustering of tsunami sources is also indicated by the distribution of interevent times for both data sets. Tsunami event clusters consist only of two to four events, in contrast to protracted sequences of earthquakes that make up foreshock-main shock-aftershock sequences. From past studies of seismicity, it is likely that there is a physical triggering mechanism responsible for events within the tsunami source 'mini-clusters'. In conclusion, prominent transient rate increases in the occurrence of global tsunamis appear to be caused by temporal grouping of geographically distinct mini-clusters, in addition to the random preferential location of global M >7 earthquakes along offshore fault zones.

Differences in tsunami generation between the December 26, 2004 and March 28, 2005 Sumatra earthquakes

USGS Publications Warehouse

Geist, E.L.; Bilek, S.L.; Arcas, D.; Titov, V.V.

2006-01-01

Source parameters affecting tsunami generation and propagation for the Mw > 9.0 December 26, 2004 and the Mw = 8.6 March 28, 2005 earthquakes are examined to explain the dramatic difference in tsunami observations. We evaluate both scalar measures (seismic moment, maximum slip, potential energy) and finite-source repre-sentations (distributed slip and far-field beaming from finite source dimensions) of tsunami generation potential. There exists significant variability in local tsunami runup with respect to the most readily available measure, seismic moment. The local tsunami intensity for the December 2004 earthquake is similar to other tsunamigenic earthquakes of comparable magnitude. In contrast, the March 2005 local tsunami was deficient relative to its earthquake magnitude. Tsunami potential energy calculations more accurately reflect the difference in tsunami severity, although these calculations are dependent on knowledge of the slip distribution and therefore difficult to implement in a real-time system. A significant factor affecting tsunami generation unaccounted for in these scalar measures is the location of regions of seafloor displacement relative to the overlying water depth. The deficiency of the March 2005 tsunami seems to be related to concentration of slip in the down-dip part of the rupture zone and the fact that a substantial portion of the vertical displacement field occurred in shallow water or on land. The comparison of the December 2004 and March 2005 Sumatra earthquakes presented in this study is analogous to previous studies comparing the 1952 and 2003 Tokachi-Oki earthquakes and tsunamis, in terms of the effect slip distribution has on local tsunamis. Results from these studies indicate the difficulty in rapidly assessing local tsunami runup from magnitude and epicentral location information alone.

Probabilistic tsunami hazard analysis: Multiple sources and global applications

USGS Publications Warehouse

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.

Probabilistic Tsunami Hazard Analysis: Multiple Sources and Global Applications

NASA Astrophysics Data System (ADS)

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.

Probabilistic analysis of tsunami hazards

USGS Publications Warehouse

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).

Impact of Near-Field, Deep-Ocean Tsunami Observations on Forecasting the 7 December 2012 Japanese Tsunami

NASA Astrophysics Data System (ADS)

Bernard, Eddie; Wei, Yong; Tang, Liujuan; Titov, Vasily

2014-12-01

Following the devastating 11 March 2011 tsunami, two deep-ocean assessment and reporting of tsunamis (DART®)(DART® and the DART® logo are registered trademarks of the National Oceanic and Atmospheric Administration, used with permission) stations were deployed in Japanese waters by the Japanese Meteorological Agency. Two weeks after deployment, on 7 December 2012, a M w 7.3 earthquake off Japan's Pacific coastline generated a tsunami. The tsunami was recorded at the two Japanese DARTs as early as 11 min after the earthquake origin time, which set a record as the fastest tsunami detecting time at a DART station. These data, along with those recorded at other DARTs, were used to derive a tsunami source using the National Oceanic and Atmospheric Administration tsunami forecast system. The results of our analysis show that data provided by the two near-field Japanese DARTs can not only improve the forecast speed but also the forecast accuracy at the Japanese tide gauge stations. This study provides important guidelines for early detection and forecasting of local tsunamis.

Source processes for the probabilistic assessment of tsunami hazards

USGS Publications Warehouse

Geist, Eric L.; Lynett, Patrick J.

2014-01-01

The importance of tsunami hazard assessment has increased in recent years as a result of catastrophic consequences from events such as the 2004 Indian Ocean and 2011 Japan tsunamis. In particular, probabilistic tsunami hazard assessment (PTHA) methods have been emphasized to include all possible ways a tsunami could be generated. Owing to the scarcity of tsunami observations, a computational approach is used to define the hazard. This approach includes all relevant sources that may cause a tsunami to impact a site and all quantifiable uncertainty. Although only earthquakes were initially considered for PTHA, recent efforts have also attempted to include landslide tsunami sources. Including these sources into PTHA is considerably more difficult because of a general lack of information on relating landslide area and volume to mean return period. The large variety of failure types and rheologies associated with submarine landslides translates to considerable uncertainty in determining the efficiency of tsunami generation. Resolution of these and several other outstanding problems are described that will further advance PTHA methodologies leading to a more accurate understanding of tsunami hazard.

Modeling influence of tide stages on forecasts of the 2010 Chilean tsunami

NASA Astrophysics Data System (ADS)

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.

The Great Chilean Tsunamis of 2010, 2014 and 2015 on the Coast and Offshore of Mexico: Comparative Features Based on Open-Ocean Energy Parameterization

NASA Astrophysics Data System (ADS)

Rabinovich, A.; Zaytsev, O.; Thomson, R.

2016-12-01

The three recent great earthquakes offshore of Chile on 27 February 2010 (Maule, Mw 8.8), 1 April 2014 (Iquique, Mw 8.2) and 16 September 2015 (Illapel, Mw 8.3) generated major trans-oceanic tsunamis that spread throughout the entire Pacific Ocean and were measured by numerous coastal tide gauges and open-ocean DART stations. Statistical and spectral analyses of the tsunami waves from the three events recorded on the Pacific coast of Mexico enabled us to compare the events and to identify coastal "hot spots", regions with maximum tsunami risk. Based on joint spectral analyses of tsunamis and background noise, we have developed a method for reconstructing the "true" tsunami spectra in the deep ocean. The "reconstructed" open-ocean tsunami spectra are in excellent agreement with the actual tsunami spectra evaluated from direct analysis of the DART records offshore of Mexico. We have further used the spectral estimates to parameterize the energy of the three Chilean tsunamis based on the total open-ocean tsunami energy and frequency content of the individual events.

U.S. Tsunami Warning System: Advancements since the 2004 Indian Ocean Tsunami (Invited)

NASA Astrophysics Data System (ADS)

Whitmore, P.

2009-12-01

The U.S. government embarked on a strengthening program for the U.S. Tsunami Warning System (TWS) in the aftermath of the disastrous 2004 Indian Ocean tsunami. The program was designed to improve several facets of the U.S. TWS, including: upgrade of the coastal sea level network - 16 new stations plus higher transmission rates; expansion of the deep ocean tsunameter network - 7 sites increased to 39; upgrade of seismic networks - both USGS and Tsunami Warning Center (TWC); increase of TWC staff to allow 24x7 coverage at two centers; development of an improved tsunami forecast system; increased preparedness in coastal communities; expansion of the Pacific Tsunami Warning Center facility; and improvement of the tsunami data archive effort at the National Geophysical Data Center. The strengthening program has been completed and has contributed to the many improvements attained in the U.S. TWS since 2004. Some of the more significant enhancements to the program are: the number of sea level and seismic sites worldwide available to the TWCs has more than doubled; the TWC areas-of-responsibility expanded to include the U.S./Canadian Atlantic coasts, Indian Ocean, Caribbean Sea, Gulf of Mexico, and U.S. Arctic coast; event response time decreased by approximately one-half; product accuracy has improved; a tsunami forecast system developed by NOAA capable of forecasting inundation during an event has been delivered to the TWCs; warning areas are now defined by pre-computed or forecasted threat versus distance or travel time, significantly reducing the amount of coast put in a warning; new warning dissemination techniques have been implemented to reach a broader audience in less time; tsunami product content better reflects the expected impact level; the number of TsunamiReady communities has quadrupled; and the historical data archive has increased in quantity and accuracy. In addition to the strengthening program, the U.S. National Tsunami Hazard Mitigation Program (NTHMP) has expanded its efforts since 2004 and improved tsunami preparedness throughout U.S. coastal communities. The NTHMP is a partnership of federal agencies and state tsunami response agencies whose efforts include: development of inundation and evacuation maps for most highly threatened communities; tsunami evacuation and educational signage for coastal communities; support for tsunami educational, awareness and planning seminars; increased number of local tsunami warning dissemination devices such as sirens; and support for regional tsunami exercises. These activities are major factors that have contributed to the increase of TsunamiReady communities throughout the country.

Tsunami response system for ports in Korea

NASA Astrophysics Data System (ADS)

Cho, H.-R.; Cho, J.-S.; Cho, Y.-S.

2015-09-01

The tsunamis that have occurred in many places around the world over the past decade have taken a heavy toll on human lives and property. The eastern coast of the Korean Peninsula is not safe from tsunamis, particularly the eastern coastal areas, which have long sustained tsunami damage. The eastern coast had been attacked by 1983 and 1993 tsunami events. The aim of this study was to mitigate the casualties and property damage against unexpected tsunami attacks along the eastern coast of the Korean Peninsula by developing a proper tsunami response system for important ports and harbors with high population densities and high concentrations of key national industries. The system is made based on numerical and physical modelings of 3 historical and 11 virtual tsunamis events, field surveys, and extensive interviews with related people.

Tsunami Research driven by Survivor Observations: Sumatra 2004, Tohoku 2011 and the Lituya Bay Landslide (Plinius Medal Lecture)

NASA Astrophysics Data System (ADS)

Fritz, Hermann M.

2014-05-01

The 10th anniversary of the 2004 Indian Ocean tsunami recalls the advent of tsunami video recordings by eyewitnesses. The tsunami of December 26, 2004 severely affected Banda Aceh along the North tip of Sumatra (Indonesia) at a distance of 250 km from the epicenter of the Magnitude 9.0 earthquake. The tsunami flow velocity analysis focused on two survivor videos recorded within Banda Aceh more than 3km from the open ocean. The exact locations of the tsunami eyewitness video recordings were revisited to record camera calibration ground control points. The motion of the camera during the recordings was determined. The individual video images were rectified with a direct linear transformation (DLT). Finally a cross-correlation based particle image velocimetry (PIV) analysis was applied to the rectified video images to determine instantaneous tsunami flow velocity fields. The measured overland tsunami flow velocities were within the range of 2 to 5 m/s in downtown Banda Aceh, Indonesia. The March 11, 2011, magnitude Mw 9.0 earthquake off the coast of Japan caused catastrophic damage and loss of life. Fortunately many survivors at evacuation sites recorded countless tsunami videos with unprecedented spatial and temporal coverage. Numerous tsunami reconnaissance trips were conducted in Japan. This report focuses on the surveys at selected tsunami eyewitness video recording locations along Japan's Sanriku coast and the subsequent tsunami video image analysis. Locations with high quality survivor videos were visited, eyewitnesses interviewed and detailed site topography scanned with a terrestrial laser scanner (TLS). The analysis of the tsunami videos followed the four step procedure developed for the analysis of 2004 Indian Ocean tsunami videos at Banda Aceh. Tsunami currents up to 11 m/s were measured in Kesennuma Bay making navigation impossible. Further tsunami height and runup hydrographs are derived from the videos to discuss the complex effects of coastal structures on inundation and outflow flow velocities. Tsunamis generated by landslides and volcanic island collapses account for some of the most catastrophic events. On July 10, 1958, an earthquake Mw 8.3 along the Fairweather fault triggered a major subaerial landslide into Gilbert Inlet at the head of Lituya Bay on the south coast of Alaska. The landslide impacted the water at high speed generating a giant tsunami and the highest wave runup in recorded history. This event was observed by eyewitnesses on board the sole surviving fishing boat, which managed to ride the tsunami. The mega-tsunami runup to an elevation of 524 m caused total forest destruction and erosion down to bedrock on a spur ridge in direct prolongation of the slide axis. A cross-section of Gilbert Inlet was rebuilt in a two dimensional physical laboratory model. Particle image velocimetry (PIV) provided instantaneous velocity vector fields of decisive initial phase with landslide impact and wave generation as well as the runup on the headland. Three dimensional source and runup scenarios based on real world events are physically modeled in the NEES tsunami wave basin (TWB) at Oregon State University (OSU). The measured landslide and tsunami data serve to validate and advance numerical landslide tsunami models. This lecture encompasses multi-hazard aspects and implications of recent tsunami and cyclonic events around the world such as the November 2013 Typhoon Haiyan (Yolanda) in the Philippines.

Rapid Tsunami Inundation Forecast from Near-field or Far-field Earthquakes using Pre-computed Tsunami Database: Pelabuhan Ratu, Indonesia

NASA Astrophysics Data System (ADS)

Gusman, A. R.; Setiyono, U.; Satake, K.; Fujii, Y.

2017-12-01

We built pre-computed tsunami inundation database in Pelabuhan Ratu, one of tsunami-prone areas on the southern coast of Java, Indonesia. The tsunami database can be employed for a rapid estimation of tsunami inundation during an event. The pre-computed tsunami waveforms and inundations are from a total of 340 scenarios ranging from 7.5 to 9.2 in moment magnitude scale (Mw), including simple fault models of 208 thrust faults and 44 tsunami earthquakes on the plate interface, as well as 44 normal faults and 44 reverse faults in the outer-rise region. Using our tsunami inundation forecasting algorithm (NearTIF), we could rapidly estimate the tsunami inundation in Pelabuhan Ratu for three different hypothetical earthquakes. The first hypothetical earthquake is a megathrust earthquake type (Mw 9.0) offshore Sumatra which is about 600 km from Pelabuhan Ratu to represent a worst-case event in the far-field. The second hypothetical earthquake (Mw 8.5) is based on a slip deficit rate estimation from geodetic measurements and represents a most likely large event near Pelabuhan Ratu. The third hypothetical earthquake is a tsunami earthquake type (Mw 8.1) which often occur south off Java. We compared the tsunami inundation maps produced by the NearTIF algorithm with results of direct forward inundation modeling for the hypothetical earthquakes. The tsunami inundation maps produced from both methods are similar for the three cases. However, the tsunami inundation map from the inundation database can be obtained in much shorter time (1 min) than the one from a forward inundation modeling (40 min). These indicate that the NearTIF algorithm based on pre-computed inundation database is reliable and useful for tsunami warning purposes. This study also demonstrates that the NearTIF algorithm can work well even though the earthquake source is located outside the area of fault model database because it uses a time shifting procedure for the best-fit scenario searching.

Real-time correction of tsunami site effect by frequency-dependent tsunami-amplification factor

NASA Astrophysics Data System (ADS)

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.

A Collaborative Effort Between Caribbean States for Tsunami Numerical Modeling: Case Study CaribeWave15

NASA Astrophysics Data System (ADS)

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 countries, are critical to assess tsunami hazard and increase preparedness within the countries.

New Activities of the U.S. National Tsunami Hazard Mitigation Program, Mapping and Modeling Subcommittee

NASA Astrophysics Data System (ADS)

Wilson, R. I.; Eble, M. C.

2013-12-01

The U.S. National Tsunami Hazard Mitigation Program (NTHMP) is comprised of representatives from coastal states and federal agencies who, under the guidance of NOAA, work together to develop protocols and products to help communities prepare for and mitigate tsunami hazards. Within the NTHMP are several subcommittees responsible for complimentary aspects of tsunami assessment, mitigation, education, warning, and response. The Mapping and Modeling Subcommittee (MMS) is comprised of state and federal scientists who specialize in tsunami source characterization, numerical tsunami modeling, inundation map production, and warning forecasting. Until September 2012, much of the work of the MMS was authorized through the Tsunami Warning and Education Act, an Act that has since expired but the spirit of which is being adhered to in parallel with reauthorization efforts. Over the past several years, the MMS has developed guidance and best practices for states and territories to produce accurate and consistent tsunami inundation maps for community level evacuation planning, and has conducted benchmarking of numerical inundation models. Recent tsunami events have highlighted the need for other types of tsunami hazard analyses and products for improving evacuation planning, vertical evacuation, maritime planning, land-use planning, building construction, and warning forecasts. As the program responsible for producing accurate and consistent tsunami products nationally, the NTHMP-MMS is initiating a multi-year plan to accomplish the following: 1) Create and build on existing demonstration projects that explore new tsunami hazard analysis techniques and products, such as maps identifying areas of strong currents and potential damage within harbors as well as probabilistic tsunami hazard analysis for land-use planning. 2) Develop benchmarks for validating new numerical modeling techniques related to current velocities and landslide sources. 3) Generate guidance and protocols for the production and use of new tsunami hazard analysis products. 4) Identify multistate collaborations and funding partners interested in these new products. Application of these new products will improve the overall safety and resilience of coastal communities exposed to tsunami hazards.

A Collaborative Effort Between Caribbean States for Tsunami Numerical Modeling: Case Study CaribeWave15

NASA Astrophysics Data System (ADS)

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 countries, are critical to assess tsunami hazard and increase preparedness within the countries.

Tsunami mitigation and preparedness activities in California: Chapter L in The SAFRR (Science Application for Risk Reduction) Tsunami Scenario

USGS Publications Warehouse

Wilson, Rick; Miller, Kevin H.

2013-01-01

scenario-specific, tsunami evacuation “playbook” maps and guidance in-harbor hazard maps and offshore safety zones for potential boat evacuation during future distant source events; “probability-based” products for land-use planning under the California Seismic Hazard Mapping Act; and an expansion of real-time and post-tsunami field reconnaissance teams and information sharing through a state-wide clearinghouse. The state tsunami program has benefitted greatly from participation in the SAFRR tsunami scenario process, and hopes to continue this relationship with the U.S. Geological Survey to help improve tsunami preparedness in California.

Modeling the 2004Indian Ocean Tsunami for Introductory Physics Students

NASA Astrophysics Data System (ADS)

DiLisi, Gregory A.; Rarick, Richard A.

2006-12-01

In this paper we develop materials to address student interest in the Indian Ocean tsunami of December 2004. We discuss the physical characteristics of tsunamis and some of the specific data regarding the 2004 event. Finally, we create an easy-to-make tsunami tank to run simulations in the classroom. The simulations exhibit three dramatic signatures of tsunamis, namely, as a tsunami moves into shallow water its amplitude increases, its wavelength and speed decrease, and its leading edge becomes increasingly steep as if to "break" or "crash." Using our tsunami tank, these realistic features were easy to observe in the classroom and evoked an enthusiastic response from our students.

Our fingerprint in tsunami deposits - anthropogenic markers as a new tsunami identification tool

NASA Astrophysics Data System (ADS)

Bellanova, P.; Schwarzbauer, J.; Reicherter, K. R.; Jaffe, B. E.; Szczucinski, W.

2016-12-01

Several recent geochemical studies have focused on the use of inorganic indicators to evaluate a tsunami origin of sediment in the geologic record. However, tsunami transport not only particulate sedimentary material from marine to terrestrial areas (and vice versa), but also associated organic material. Thus, tsunami deposits may be characterized by organic-geochemical parameters. Recently increased attention has been given to the use of natural organic substances (biomarkers) to identify tsunami deposits. To date no studies have been made investigating anthropogenic organic indicators in recent tsunami deposits. Anthropogenic organic markers are more sensitive and reliable markers compared to other tracers due to their specific molecular structural properties and higher source specificity. In this study we evaluate whether anthropogenic substances are useful indicators for determining whether an area has been inundated by a tsunami. We chose the Sendai Plain and Sanemoura and Oppa Bays, Japan, as study sites because the destruction of infrastructure by flooding released environmental pollutants (e.g., fuels, fats, tarmac, plastics, heavy metals, etc.) contaminating large areas of the coastal zone during the 2011 Tohoku-oki tsunami. Organic compounds from the tsunami deposits are extracted from tsunami sediment and compared with the organic signature of unaffected pre-tsunami samples using gas chromatography-mass spectrometry (GS/MS) based analyses. For the anthropogenic markers, compounds such as soil derived pesticides (DDT), source specific PAHs, halogenated aromatics from industrial sources were detected and used to observe the inland extent and the impact of the Tohoku-oki tsunami on the coastal region around Sendai.

Mega Tsunamis of the World Ocean and Their Implication for the Tsunami Hazard Assessment

NASA Astrophysics Data System (ADS)

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.

Tsunami Field Survey for the Solomon Islands Earthquake of April 1, 2007

NASA Astrophysics Data System (ADS)

Nishimura, Y.; Tanioka, Y.; Nakamura, Y.; Tsuji, Y.; Namegaya, Y.; Murata, M.; Woodward, S.

2007-12-01

Two weeks after the 2007 off-Solomon earthquake, an international tsunami survey team (ITST) of Japanese and US researchers performed a post tsunami survey in Ghizo and adjacent islands. Main purpose of the team was to provide information on the earthquake and tsunami to the national disaster council of the Solomon Islands, who was responsible for the disaster management at that time. The ITST had interview with the affected people and conducted reconnaissance mapping of the tsunami heights and flow directions. Tsunami flow heights at beach and inland were evaluated from watermarks on buildings and the position of broken branches and stuck materials on trees. These tsunami heights along the southern to western coasts of Ghizo Island were ca. 5m (a.s.l.). Tsunami run-up was traced by distribution of floating debris that carried up by the tsunami and deposited at their inundation limit. The maximum run-up was measured at Tapurai of Simbo Island to be ca. 9 m. Most of the inundation area was covered by 0-10 cm thick tsunami deposit that consists of beach sand, coral peaces and eroded soil. Coseismic uplift and subsidence were clearly identified by changes of the sea level before and after the earthquake, that were inferred by eyewitness accounts and evidences such as dried up coral reeves. These deformation patterns, as well as the tsunami height distribution, could constrain the earthquake fault geometry and motion. It is worthy of mention that the tsunami damage in villages in Ranongga Island has significantly reduced by 2-3 m uplift before the tsunami attack.

Near Field Modeling for the Maule Tsunami from DART, GPS and Finite Fault Solutions (Invited)

NASA Astrophysics Data System (ADS)

Arcas, D.; Chamberlin, C.; Lagos, M.; Ramirez-Herrera, M.; Tang, L.; Wei, Y.

2010-12-01

The earthquake and tsunami of February, 27, 2010 in central Chile has rekindled an interest in developing techniques to predict the impact of near field tsunamis along the Chilean coastline. Following the earthquake, several initiatives were proposed to increase the density of seismic, pressure and motion sensors along the South American trench, in order to provide field data that could be used to estimate tsunami impact on the coast. However, the precise use of those data in the elaboration of a quantitative assessment of coastal tsunami damage has not been clarified. The present work makes use of seismic, Deep-ocean Assessment and Reporting of Tsunamis (DART®) systems, and GPS measurements obtained during the Maule earthquake to initiate a number of tsunami inundation models along the rupture area by expressing different versions of the seismic crustal deformation in terms of NOAA’s tsunami unit source functions. Translation of all available real-time data into a feasible tsunami source is essential in near-field tsunami impact prediction in which an impact assessment must be generated under very stringent time constraints. Inundation results from each different source are then contrasted with field and tide gauge data by comparing arrival time, maximum wave height, maximum inundation and tsunami decay rate, using field data collected by the authors.

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

Tsunami risk zoning in south-central Chile

NASA Astrophysics Data System (ADS)

Lagos, M.

2010-12-01

The recent 2010 Chilean tsunami revealed the need to optimize methodologies for assessing the risk of disaster. In this context, modern techniques and criteria for the evaluation of the tsunami phenomenon were applied in the coastal zone of south-central Chile as a specific methodology for the zoning of tsunami risk. This methodology allows the identification and validation of a scenario of tsunami hazard; the spatialization of factors that have an impact on the risk; and the zoning of the tsunami risk. For the hazard evaluation, different scenarios were modeled by means of numerical simulation techniques, selecting and validating the results that better fit with the observed tsunami data. Hydrodynamic parameters of the inundation as well as physical and socioeconomic vulnerability aspects were considered for the spatialization of the factors that affect the tsunami risk. The tsunami risk zoning was integrated into a Geographic Information System (GIS) by means of multicriteria evaluation (MCE). The results of the tsunami risk zoning show that the local characteristics and their location, together with the concentration of poverty levels, establish spatial differentiated risk levels. This information builds the basis for future applied studies in land use planning that tend to minimize the risk levels associated to the tsunami hazard. This research is supported by Fondecyt 11090210.

Tsunami damage in the southern Kanto region from the 1703 Genroku Kanto earthquake

NASA Astrophysics Data System (ADS)

Muragishi, J.; Satake, K.

2014-12-01

The Genroku Kanto earthquake occurred on Dec. 31th, 1703 along the Sagami Trough where the Philippine Sea plate subducts beneath the continental plate. Hatori (1976) reported significant tsunami damage with estimated tsunami heights of 5 m along Kujukuri coast on the Pacific Ocean, and estimated the tsunami heights in the inner Tokyo Bay as approximately 2 m. In Tokyo Bay, there are no records that indicate the tsunami inundated residential areas, while some descriptions of tsunami are recorded in Edo, the former Tokyo. The notice from Edo City Commissioners to residences in Edo described that the tsunami came up to the upper-limit of Sumida River in Tokyo, where four major arrivals of tsunamis were reported. According to Saihen-onkoroku, tsunami came to Fukagawa, where one person was killed by throwing away from a boat affected by the tsunami. In Ichikawa along the coast of Chiba Prefecture in Tokyo Bay, there are historical records about the salt farm. The embankments were collapsed and the salt farm was ruined, while the tsunami damage is not described. At this location, the damage due to storm surge in 1680 is recorded in the same document. Although storm surge damage is recorded in detail, there are no records about the Genroku tsunami, suggesting that the tsunami damage, if any, is slighter than the storm surge. Along the Kujukui coast outside the Tokyo bay, the descriptions are not only damage to buildings or deaths but also an influx of sand brought by the tsunami which damaged the agricultural land. In summary, it became certain that the Genroku tsunami caused some damage in the inner Tokyo Bay area. In addition, we found that a wide range of farmland was suffered by influx of sand and crops could not grow well. Such a description may be able to contribute to the tsunami deposits in future research. This study was supported by the Special Project for Reducing Vulnerability for Urban Mega Earthquake Disasters from the MEXT of Japan.

Earthquake and submarine landslide tsunamis: how can we tell the difference? (Invited)

NASA Astrophysics Data System (ADS)

Tappin, D. R.; Grilli, S. T.; Harris, J.; Geller, R. J.; Masterlark, T.; Kirby, J. T.; Ma, G.; Shi, F.

2013-12-01

Several major recent events have shown the tsunami hazard from submarine mass failures (SMF), i.e., submarine landslides. In 1992 a small earthquake triggered landslide generated a tsunami over 25 meters high on Flores Island. In 1998 another small, earthquake-triggered, sediment slump-generated tsunami up to 15 meters high devastated the local coast of Papua New Guinea killing 2,200 people. It was this event that led to the recognition of the importance of marine geophysical data in mapping the architecture of seabed sediment failures that could be then used in modeling and validating the tsunami generating mechanism. Seabed mapping of the 2004 Indian Ocean earthquake rupture zone demonstrated, however, that large, if not great, earthquakes do not necessarily cause major seabed failures, but that along some convergent margins frequent earthquakes result in smaller sediment failures that are not tsunamigenic. Older events, such as Messina, 1908, Makran, 1945, Alaska, 1946, and Java, 2006, all have the characteristics of SMF tsunamis, but for these a SMF source has not been proven. When the 2011 tsunami struck Japan, it was generally assumed that it was directly generated by the earthquake. The earthquake has some unusual characteristics, such as a shallow rupture that is somewhat slow, but is not a 'tsunami earthquake.' A number of simulations of the tsunami based on an earthquake source have been published, but in general the best results are obtained by adjusting fault rupture models with tsunami wave gauge or other data so, to the extent that they can model the recorded tsunami data, this demonstrates self-consistency rather than validation. Here we consider some of the existing source models of the 2011 Japan event and present new tsunami simulations based on a combination of an earthquake source and an SMF mapped from offshore data. We show that the multi-source tsunami agrees well with available tide gauge data and field observations and the wave data from offshore buoys, and that the SMF generated the large runups in the Sanriku region (northern Tohoku). Our new results for the 2011 Tohoku event suggest that care is required in using tsunami wave and tide gauge data to both model and validate earthquake tsunami sources. They also suggest a potential pitfall in the use of tsunami waveform inversion from tide gauges and buoys to estimate the size and spatial characteristics of earthquake rupture. If the tsunami source has a significant SMF component such studies may overestimate earthquake magnitude. Our seabed mapping identifies other large SMFs off Sanriku that have the potential to generate significant tsunamis and which should be considered in future analyses of the tsunami hazard in Japan. The identification of two major SMF-generated tsunamis (PNG and Tohoku), especially one associated with a M9 earthquake, is important in guiding future efforts at forecasting and mitigating the tsunami hazard from large megathrust plus SMF events both in Japan and globally.

NOAA/West coast and Alaska Tsunami warning center Atlantic Ocean response criteria

USGS Publications Warehouse

Whitmore, P.; Refidaff, C.; Caropolo, M.; Huerfano-Moreno, V.; Knight, W.; Sammler, W.; Sandrik, A.

2009-01-01

West Coast/Alaska Tsunami Warning Center (WCATWC) response criteria for earthquakesoccurring in the Atlantic and Caribbean basins are presented. Initial warning center decisions are based on an earthquake's location, magnitude, depth, distance from coastal locations, and precomputed threat estimates based on tsunami models computed from similar events. The new criteria will help limit the geographical extent of warnings and advisories to threatened regions, and complement the new operational tsunami product suite. Criteria are set for tsunamis generated by earthquakes, which are by far the main cause of tsunami generation (either directly through sea floor displacement or indirectly by triggering of sub-sea landslides).The new criteria require development of a threat data base which sets warning or advisory zones based on location, magnitude, and pre-computed tsunami models. The models determine coastal tsunami amplitudes based on likely tsunami source parameters for a given event. Based on the computed amplitude, warning and advisory zones are pre-set.

Highly variable recurrence of tsunamis in the 7,400 years before the 2004 Indian Ocean tsunami

PubMed Central

Rubin, Charles M.; Horton, Benjamin P.; Sieh, Kerry; Pilarczyk, Jessica E.; Daly, Patrick; Ismail, Nazli; Parnell, Andrew C.

2017-01-01

The devastating 2004 Indian Ocean tsunami caught millions of coastal residents and the scientific community off-guard. Subsequent research in the Indian Ocean basin has identified prehistoric tsunamis, but the timing and recurrence intervals of such events are uncertain. Here we present an extraordinary 7,400 year stratigraphic sequence of prehistoric tsunami deposits from a coastal cave in Aceh, Indonesia. This record demonstrates that at least 11 prehistoric tsunamis struck the Aceh coast between 7,400 and 2,900 years ago. The average time period between tsunamis is about 450 years with intervals ranging from a long, dormant period of over 2,000 years, to multiple tsunamis within the span of a century. Although there is evidence that the likelihood of another tsunamigenic earthquake in Aceh province is high, these variable recurrence intervals suggest that long dormant periods may follow Sunda megathrust ruptures as large as that of the 2004 Indian Ocean tsunami. PMID:28722009

Highly variable recurrence of tsunamis in the 7,400 years before the 2004 Indian Ocean tsunami.

PubMed

Rubin, Charles M; Horton, Benjamin P; Sieh, Kerry; Pilarczyk, Jessica E; Daly, Patrick; Ismail, Nazli; Parnell, Andrew C

2017-07-19

The devastating 2004 Indian Ocean tsunami caught millions of coastal residents and the scientific community off-guard. Subsequent research in the Indian Ocean basin has identified prehistoric tsunamis, but the timing and recurrence intervals of such events are uncertain. Here we present an extraordinary 7,400 year stratigraphic sequence of prehistoric tsunami deposits from a coastal cave in Aceh, Indonesia. This record demonstrates that at least 11 prehistoric tsunamis struck the Aceh coast between 7,400 and 2,900 years ago. The average time period between tsunamis is about 450 years with intervals ranging from a long, dormant period of over 2,000 years, to multiple tsunamis within the span of a century. Although there is evidence that the likelihood of another tsunamigenic earthquake in Aceh province is high, these variable recurrence intervals suggest that long dormant periods may follow Sunda megathrust ruptures as large as that of the 2004 Indian Ocean tsunami.

Near-field hazard assessment of March 11, 2011 Japan Tsunami sources inferred from different methods

USGS Publications Warehouse

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.

U.S. States and Territories National Tsunami Hazard Assessment: Historical record and sources for waves – Update

USGS Publications Warehouse

Dunbar, Paula K.; Weaver, Craig S.

2015-01-01

The first U.S. Tsunami Hazard Assessment (Dunbar and Weaver, 2008) was prepared at the request of the National Tsunami Hazard Mitigation Program (NTHMP). The NTHMP is a partnership formed between federal and state agencies to reduce the impact of tsunamis through hazard assessment, warning guidance, and mitigation. The assessment was conducted in response to a 2005 joint report by the Sub-Committee on Disaster Reduction and the U.S. Group on Earth Observations entitled Tsunami Risk Reduction for the United States: A Framework for Action. The first specific action called for in the Framework was to “develop standardized and coordinated tsunami hazard and risk assessments for all coastal regions of the United States and its territories.” Since the first assessment, there have been a number of very significant tsunamis, including the 2009 Samoa, 2010 Chile, and 2011 Japan tsunamis. As a result, the NTHMP requested an update of the U.S. tsunami hazard assessment.

Highly variable recurrence of tsunamis in the 7,400 years before the 2004 Indian Ocean tsunami

NASA Astrophysics Data System (ADS)

Rubin, Charles M.; Horton, Benjamin P.; Sieh, Kerry; Pilarczyk, Jessica E.; Daly, Patrick; Ismail, Nazli; Parnell, Andrew C.

2017-07-01

The devastating 2004 Indian Ocean tsunami caught millions of coastal residents and the scientific community off-guard. Subsequent research in the Indian Ocean basin has identified prehistoric tsunamis, but the timing and recurrence intervals of such events are uncertain. Here we present an extraordinary 7,400 year stratigraphic sequence of prehistoric tsunami deposits from a coastal cave in Aceh, Indonesia. This record demonstrates that at least 11 prehistoric tsunamis struck the Aceh coast between 7,400 and 2,900 years ago. The average time period between tsunamis is about 450 years with intervals ranging from a long, dormant period of over 2,000 years, to multiple tsunamis within the span of a century. Although there is evidence that the likelihood of another tsunamigenic earthquake in Aceh province is high, these variable recurrence intervals suggest that long dormant periods may follow Sunda megathrust ruptures as large as that of the 2004 Indian Ocean tsunami.

Hydro- and morphodynamic tsunami simulations for the Ambrakian Gulf (Greece) and comparison with geoscientific field traces

NASA Astrophysics Data System (ADS)

Röbke, B. R.; Schüttrumpf, H.; Vött, A.

2018-04-01

In order to derive local tsunami risks for a particular coast, hydro- and morphodynamic numerical models that are calibrated and compared with sedimentary field data of past tsunami impacts have proven very effective. While this approach has widely been used with regard to recent tsunami events, comparable investigations into pre-/historical tsunami impacts hardly exist, which is the objective of this study focusing on the Ambrakian Gulf in northwestern Greece. The Ambrakian Gulf is located in the most active seismotectonic and by this most tsunamigenic area of the Mediterranean. Accordingly, palaeotsunami field studies have revealed repeated tsunami impacts on the gulf during the past 8000 yr. The current study analyses 151 vibracores of the Ambrakian Gulf coast in order to evaluate tsunami signals in the sedimentary record. Based on a hydro- and morphodynamic numerical model of the study area, various tsunami waves are simulated with the aim of finding scenarios that compare favourably with tsunami deposits detected in the field. Both, field data and simulation results suggest a decreasing tsunami influence from the western to the eastern Ambrakian Gulf. Various scenarios are needed to explain tsunami deposits in different parts of the gulf. Whereas shorter period tsunami waves (T = 30 min) from the south and west compare favourably with field data in the western gulf, longer period waves (T = 80 min) from a western direction show the best agreement with tsunami sediments detected in southwestern Aktio Headland and in the more central parts of the Ambrakian Gulf including Lake Voulkaria. Tsunamis from the southwest generally do not accord with field traces. Besides the spatial sediment distribution, the numerical model accurately reflects the sedimentary composition of the detected event deposits and reproduces a number of essential features typical of tsunamites, which were also observed in the field. Such include fining- and thinning-landward and the marine character of the deposits. By contrast, the simulated thickness of tsunami sediments usually lags behind the observed thickness in the field and some event layers cannot be explained by any of the simulated scenarios. Regarding the frequency of past tsunami events and their spatial dimensions indicated by both field data and simulation results, a high tsunami risk has to be derived for the Ambrakian Gulf.

Tsunami Source Identification on the 1867 Tsunami Event Based on the Impact Intensity

NASA Astrophysics Data System (ADS)

Wu, T. R.

2014-12-01

The 1867 Keelung tsunami event has drawn significant attention from people in Taiwan. Not only because the location was very close to the 3 nuclear power plants which are only about 20km away from the Taipei city but also because of the ambiguous on the tsunami sources. This event is unique in terms of many aspects. First, it was documented on many literatures with many languages and with similar descriptions. Second, the tsunami deposit was discovered recently. Based on the literatures, earthquake, 7-meter tsunami height, volcanic smoke, and oceanic smoke were observed. Previous studies concluded that this tsunami was generated by an earthquake with a magnitude around Mw7.0 along the Shanchiao Fault. However, numerical results showed that even a Mw 8.0 earthquake was not able to generate a 7-meter tsunami. Considering the steep bathymetry and intense volcanic activities along the Keelung coast, one reasonable hypothesis is that different types of tsunami sources were existed, such as the submarine landslide or volcanic eruption. In order to confirm this scenario, last year we proposed the Tsunami Reverse Tracing Method (TRTM) to find the possible locations of the tsunami sources. This method helped us ruling out the impossible far-field tsunami sources. However, the near-field sources are still remain unclear. This year, we further developed a new method named 'Impact Intensity Analysis' (IIA). In the IIA method, the study area is divided into a sequence of tsunami sources, and the numerical simulations of each source is conducted by COMCOT (Cornell Multi-grid Coupled Tsunami Model) tsunami model. After that, the resulting wave height from each source to the study site is collected and plotted. This method successfully helped us to identify the impact factor from the near-field potential sources. The IIA result (Fig. 1) shows that the 1867 tsunami event was a multi-source event. A mild tsunami was trigged by a Mw7.0 earthquake, and then followed by the submarine landslide or volcanic events. A near-field submarine landslide and landslide at Mien-Hwa Canyon were the most possible scenarios. As for the volcano scenarios, the volcanic eruption located about 10 km away from Keelung with 2.5x108 m3 disturbed water volume might be a candidate. The detailed scenario results will be presented in the full paper.

Probabilistic Tsunami Hazard Analysis

NASA Astrophysics Data System (ADS)

Thio, H. K.; Ichinose, G. A.; Somerville, P. G.; Polet, J.

2006-12-01

The recent tsunami disaster caused by the 2004 Sumatra-Andaman earthquake has focused our attention to the hazard posed by large earthquakes that occur under water, in particular subduction zone earthquakes, and the tsunamis that they generate. Even though these kinds of events are rare, the very large loss of life and material destruction caused by this earthquake warrant a significant effort towards the mitigation of the tsunami hazard. For ground motion hazard, Probabilistic Seismic Hazard Analysis (PSHA) has become a standard practice in the evaluation and mitigation of seismic hazard to populations in particular with respect to structures, infrastructure and lifelines. Its ability to condense the complexities and variability of seismic activity into a manageable set of parameters greatly facilitates the design of effective seismic resistant buildings but also the planning of infrastructure projects. Probabilistic Tsunami Hazard Analysis (PTHA) achieves the same goal for hazards posed by tsunami. There are great advantages of implementing such a method to evaluate the total risk (seismic and tsunami) to coastal communities. The method that we have developed is based on the traditional PSHA and therefore completely consistent with standard seismic practice. Because of the strong dependence of tsunami wave heights on bathymetry, we use a full waveform tsunami waveform computation in lieu of attenuation relations that are common in PSHA. By pre-computing and storing the tsunami waveforms at points along the coast generated for sets of subfaults that comprise larger earthquake faults, we can efficiently synthesize tsunami waveforms for any slip distribution on those faults by summing the individual subfault tsunami waveforms (weighted by their slip). This efficiency make it feasible to use Green's function summation in lieu of attenuation relations to provide very accurate estimates of tsunami height for probabilistic calculations, where one typically computes thousands of earthquake scenarios. We have carried out preliminary tsunami hazard calculations for different return periods for western North America and Hawaii based on thousands of earthquake scenarios around the Pacific rim and along the coast of North America. We will present tsunami hazard maps for several return periods and also discuss how to use these results for probabilistic inundation and runup mapping. Our knowledge of certain types of tsunami sources is very limited (e.g. submarine landslides), but a probabilistic framework for tsunami hazard evaluation can include even such sources and their uncertainties and present the overall hazard in a meaningful and consistent way.

The Contribution of Coseismic Displacements due to Splay Faults Into the Local Wavefield of the 1964 Alaska Tsunami

NASA Astrophysics Data System (ADS)

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 sources produce very similar waveforms in the far field that are also in good agreement with the tide gage records. In order to study the near-field tsunami effects, we will construct embedded telescoping bathymetry grids around tsunami generation area to calculate tsunami arrival times and sea surface heights for both source models of the 1964 earthquake, and use available observation data to verify the model results.

Evaluation of Tsunami Hazards in Kuwait from Possible Earthquake and Landslide Sources considering Effect of Natural Tide

NASA Astrophysics Data System (ADS)

Latcharote, P.

2016-12-01

Kuwait is one of the most important oil producers to the world and most of population and many vital facilities are located along the coasts. However, even with low or unknown tsunami risk, it is important to investigate tsunami hazards in this country to ensure safety of life and sustain the global economy. This study aimed to evaluate tsunami hazards along the coastal areas of Kuwait from both earthquake and landslide sources using numerical modeling. Tsunami generation and propagation was simulated using the two-layer model and the TUNAMI model. Four cases of earthquake scenarios are expected to generate tsunami along the Makran Subduction Zone (MSZ) based on historical events and worst cases possible to simulate tsunami propagation to the coastal areas of the Arabian Gulf. Case 1 (Mw 8.3) and Case 2 (Mw 8.3) are the replication of the 1945 Makran earthquake, whereas Case 3 (Mw 8.6) and Case 4 (Mw 9.0) are the worst-case scenarios. Tsunami numerical simulation was modelled with mesh size 30 arc-second using bathymetry and topography data from GEBCO. Preliminary results suggested that tsunamis generated by Case 1 and Case 2 will impose very small effects to Kuwait (< 0.1 m) while Case 3 and Case 4 can generate maximum tsunami amplitude up to 0.3 m to 1.0 m after 12 hours from the earthquake. In addition, this study considered tsunamis generated by landslide along the opposite Iranian coast of Kuwait bay. To preliminarily assess tsunami hazards, coastal landslides were assumed occurred at the volume of 1.0-2.0 km3 at three possible locations from their topographic features. The preliminary results revealed that tsunami generated by coastal landslides could impose a significant tsunami impact to Kuwait having maximum tsunami amplitude at the Falika Island in front of Kuwait bay and Azzour power and desalination plant about 0.5 m- 1.1 m depending on landslide volume and energy dissipation. Future works will include more accuracy of tsunami numerical simulation with higher resolution of bathymetry and topography data in order to investigate tsunami inundation. Furthermore, detailed analysis on possible landslide sources will be performed by means of 3D-slope stability analysis in order to know the exact locations and landslide volumes taking into account the geological conditions, such as surface elevation and soil property data.

Tsunami Early Warning via a Physics-Based Simulation Pipeline

NASA Astrophysics Data System (ADS)

Wilson, J. M.; Rundle, J. B.; Donnellan, A.; Ward, S. N.; Komjathy, A.

2017-12-01

Through independent efforts, physics-based simulations of earthquakes, tsunamis, and atmospheric signatures of these phenomenon have been developed. With the goal of producing tsunami forecasts and early warning tools for at-risk regions, we join these three spheres to create a simulation pipeline. The Virtual Quake simulator can produce thousands of years of synthetic seismicity on large, complex fault geometries, as well as the expected surface displacement in tsunamigenic regions. These displacements are used as initial conditions for tsunami simulators, such as Tsunami Squares, to produce catalogs of potential tsunami scenarios with probabilities. Finally, these tsunami scenarios can act as input for simulations of associated ionospheric total electron content, signals which can be detected by GNSS satellites for purposes of early warning in the event of a real tsunami. We present the most recent developments in this project.

A Review of Methodologies on Vulnerability Assessment of Buildings to Tsunami Damage

NASA Astrophysics Data System (ADS)

Gunasekera, R.; Rosetto, T.; Tabuchi, S.; Suppasri, A.; Futami, T.; Scott, I.; Maegawa, H.

2012-04-01

The infrequency, suddenness and violence tsunamis has led to a lack of knowledge on tsunami and lack of data available for the calibration of numerical models particularly in relation to tsunami damage. Therefore, there are very few tsunami structural vulnerability studies available. Of the available literature, most of these started after the disastrous 2004 Indian Ocean event. Most of fragility curves have been developed in some areas struck by the 2004 tsunami, which are very different in architecture and engineering respect to the US, Japanese or European ones. This review aims to highlight the strengths and weaknesses of current knowledge on tsunami fragility by critically assessing several fragility curves based on post tsunami damage surveys in Chile, Japan (including initial findings of the March 2011 event), Samoa, Sri Lanka and Thailand. It is observed that there is no consensus on how to derive tsunami fragility curves. Most of the examined relationships are seen to relate to residential buildings, and, due to the location of recent tsunami occurrences, they mostly represent non-engineered buildings (i.e. all use data from Thailand, Sri Lanka, Samoa, or Sumatra), which limits their usefulness. In the absence of a good understanding of tsunami actions on buildings most existing fragility relationships adopt inundation depth as the hazard parameter in the vulnerability function, which does not account for the other components of onshore flow contributing to tsunami loads on buildings, such as flow velocity.

Interviewing insights regarding the fatalities inflicted by the 2011 Great East Japan Earthquake

NASA Astrophysics Data System (ADS)

Ando, M.; Ishida, M.; Hayashi, Y.; Mizuki, C.; Nishikawa, Y.; Tu, Y.

2013-09-01

One hundred fifty survivors of the 11 March 2011 Great East Japan Earthquake (Tohoku-oki earthquake) (Mw = 9.0) were interviewed to study the causes of deaths from the associated tsunami in coastal areas of Tohoku. The first official tsunami warning underestimated the height of the tsunami and 40% of the interviewees did not obtain this warning due to immediate blackouts and a lack of communication after the earthquake. Many chose to remain in dangerous locations based on the underestimated warning and their experiences with previous smaller tsunamis and/or due to misunderstanding the mitigating effects of nearby breakwaters in blocking incoming tsunamis. Some delayed their evacuation to perform family safety checks, and in many situations, the people affected misunderstood the risks involved in tsunamis. In this area, three large tsunamis have struck in the 115 yr preceding the 2011 tsunami. These tsunamis remained in the collective memory of communities, and numerous measures against future tsunami damage, such as breakwaters and tsunami evacuation drills, had been implemented. Despite these preparedness efforts, approximately 18 500 deaths and cases of missing persons occurred. The death rate with the age of 65 and above was particularly high, four times higher than that with other age groups. These interviews indicate that deaths resulted from a variety of reasons, but if residents had taken immediate action after the major ground motion stopped, most residents might have been saved. Education about the science behind earthquakes and tsunamis could help save more lives in the future.

Display of historical and hypothetical tsunami on the coast of Sakhalin Island

NASA Astrophysics Data System (ADS)

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.

How Do Tides and Tsunamis Interact in a Highly Energetic Channel? The Case of Canal Chacao, Chile

NASA Astrophysics Data System (ADS)

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.

Verification of Reproduction Simulation of the 2011 Great East Japan Tsunami Using Time-Stamp Data

NASA Astrophysics Data System (ADS)

Honma, Motohiro; Ushiyama, Motoyuki

2014-05-01

In the 2011 off the pacific coast of Tohoku earthquake tsunami, the significant damage and loss of lives were caused by large tsunami in the pacific coastal areas of the northern Japan. It is important to understand the situation of tsunami inundation in detail in order to establish the effective measures of disaster prevention. In this study, we calculated the detailed tsunami inundation simulation of Rikuzentakata city and verified the simulation results using not only the static observed data such as inundation area and tsunami height estimated by traces but also time stamp data which were recorded to digital camera etc. We calculated the tsunami simulation by non-linear long-wave theory using the staggered grid and leap flog scheme. We used Fujii and Satake (2011)'s model ver.4.2 as the tsunami source. The inundation model of Rikuzentakata city was constructed by fine ground level data of 10m mesh. In this simulation, the shore and river banks were set in boundary of calculation mesh. At that time, we have calculated two patterns of simulation, one condition is that a bank doesn't collapse even if tsunami overflows on it, another condition is that a bank collapses if tsunami overflows on it and its discharge exceeds the threshold. We can use the inundation area data, which was obtained by Geospatial Information Authority of Japan (GSI), and height data of tsunami trace, which were obtained by the 2011 Tohoku Earthquake Joint Survey (TTJS) group, as "static" verification data. Comparing the inundation area of simulation result with its observation by GSI, both areas are matched very well. And then, correlation coefficient between tsunami height data resulted from simulation and observed by TTJS is 0.756. In order to verify tsunami arrival time, we used the time stamp data which were recorded to digital camera etc. by citizens. Ushiyama and Yokomaku (2012) collected these tsunami stamp data and estimated the arrival time in Rikuzentakata city. We compared the arrival time resulted from tsunami simulation with estimated by Ushiyama and Yokomaku (2012) for some major points. The arrival time is earlier 2-4 minutes in the condition that a bank collapses when tsunami overflows and its discharge exceeds 0.05m2/s at each mesh boundary than in the condition that a bank doesn't collapse. And, on the whole the arrival time estimated from time stamp data is in accord with the result which were calculated in the condition that a bank collapse. We could verify reproducibility about not only the final tsunami inundation situation but also the temporal change of tsunami inundation situation by using the time stamp data. Acknowledgement In this study, we used tsunami trace data obtained by The 2011 Tohoku Earthquake Tsunami Joint Survey (TTJS) Group. Reference 1) Fujii and Satake: Tsunami Source of the Off Tohoku-Pacific Earthquake on March 11, 2011, http://iisee.kenken.go.jp/staff/fujii/OffTohokuPacific2011/tsunami_ja_ver4.2and4.6.html, 2011. 2) Ushiyama and Yokomaku: Estimation of situation in Rikuzentakata city just before tsunami attack based on time stamp data, J.JSNDS31-1, pp.47-58, 2012.

Tsunami Risk in the NE Atlantic: Pilot Study for Algarve Portugal and Applications for future TWS

NASA Astrophysics Data System (ADS)

Omira, R.; Baptista, M. A.; Catita, C.; Carrilho, F.; Matias, L.

2012-04-01

Tsunami risk assessment is an essential component of any Tsunami Early Warning System due to its significant contribution to the disaster reduction by providing valuable information that serve as basis for mitigation preparedness and strategies. Generally, risk assessment combines the outputs of the hazard and the vulnerability assessment for considered exposed elements. In the NE Atlantic region, the tsunami hazard is relatively well established through compilation of tsunami historical events, evaluation of tsunamigenic sources and impact computations for site-specific coastal areas. While, tsunami vulnerability remains poorly investigated in spite of some few studies that focused on limited coastal areas of the Gulf of Cadiz region. This work seeks to present a pilot study for tsunami risk assessment that covers about 170 km of coasts of Algarve region, south of Portugal. This area of high coastal occupation and touristic activities was strongly impacted by the 1755 tsunami event as reported in various historical documents. An approach based upon a combination of tsunami hazard and vulnerability is developed in order to take into account the dynamic aspect of tsunami risk in the region that depends on the variation of hazard and vulnerability of exposed elements from a coastal point to other. Hazard study is based upon the consideration of most credible earthquake scenarios and the derivation of hazard maps through hydrodynamic modeling of inundation and tsunami arrival time. The vulnerability assessment is performed by: i) the analysis of the occupation and the population density, ii) derivation of evacuation maps and safe shelters, and iii) the analysis of population response and evacuation times. Different risk levels ranging from "low" to "high" are assigned to the coats of the studied area. Variation of human tsunami risk between the high and low touristic seasons is also considered in this study and aims to produce different tsunami risk-related scenarios. Results are presented in terms of thematic maps and GIS layers highlighting information on inundation depths and limits, evacuation plans and safe shelters, tsunami vulnerability, evacuation times and tsunami risk levels. Results can be used for national and regional tsunami disaster management and planning. This work is funded by TRIDEC (Collaborative, Complex and Critical Decision-Support in Evolving Crises) FP7, EU project and by MAREMOTI (Mareograph and field tsunami observations, modeling and vulnerability studies for Northeast Atlantic and western Mediterranean) French project. Keywords: Tsunami, Algarve-Portugal, Evacuation, Vulnerability, Risk

Tsunami Hazards - A National Threat

USGS Publications Warehouse

,

2006-01-01

In December 2004, when a tsunami killed more than 200,000 people in 11 countries around the Indian Ocean, the United States was reminded of its own tsunami risks. In fact, devastating tsunamis have struck North America before and are sure to strike again. Especially vulnerable are the five Pacific States--Hawaii, Alaska, Washington, Oregon, and California--and the U.S. Caribbean islands. In the wake of the Indian Ocean disaster, the United States is redoubling its efforts to assess the Nation's tsunami hazards, provide tsunami education, and improve its system for tsunami warning. The U.S. Geological Survey (USGS) is helping to meet these needs, in partnership with the National Oceanic and Atmospheric Administration (NOAA) and with coastal States and counties.

Seismically generated tsunamis.

PubMed

Arcas, Diego; Segur, Harvey

2012-04-13

People around the world know more about tsunamis than they did 10 years ago, primarily because of two events: a tsunami on 26 December 2004 that killed more than 200,000 people around the shores of the Indian Ocean; and an earthquake and tsunami off the coast of Japan on 11 March 2011 that killed nearly 15,000 more and triggered a nuclear accident, with consequences that are still unfolding. This paper has three objectives: (i) to summarize our current knowledge of the dynamics of tsunamis; (ii) to describe how that knowledge is now being used to forecast tsunamis; and (iii) to suggest some policy changes that might protect people better from the dangers of future tsunamis.

E A R T H - S C I E N C E S L I N K S

Science.gov Websites

TSUNAMI! NOAA TSUNAMI Project TSUNAMI Web Site TSUNAMIS in the circum-Pacific Ring of Fire The TSUNAMI DINOSAURS PLATE TECTONICS The Dinosaur Web Pages DINOSAURIA ON-LINE Fossils & Dinosaurs Earth Through opportunities in the earth sciences Geologic Time USGS Learning Web Geoscience Information Center National

Stand-alone tsunami alarm equipment

NASA Astrophysics Data System (ADS)

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.

Measuring and forecasting great tsunamis by GNSS-based vertical positioning of multiple ships

NASA Astrophysics Data System (ADS)

Inazu, D.; Waseda, T.; Hibiya, T.; Ohta, Y.

2016-12-01

Vertical ship positioning by the Global Navigation Satellite System (GNSS) was investigated for measuring and forecasting great tsunamis. We first examined existing GNSS vertical position data of a navigating vessel. The result indicated that by using the kinematic Precise Point Positioning (PPP) method, tsunamis greater than 10^-1 m can be detected from the vertical position of the ship. Based on Automatic Identification System (AIS) data, tens of cargo ships and tankers are regularly identified navigating over the Nankai Trough, southwest of Japan. We then assumed that a future Nankai Trough great earthquake tsunami will be observed by ships at locations based on AIS data. The tsunami forecast capability by these virtual offshore tsunami measurements was examined. A conventional Green's function based inversion was used to determine the initial tsunami height distribution. Tsunami forecast tests over the Nankai Trough were carried out using simulated tsunami data of the vertical positions of multiple cargo ships/tankers on a certain day, and of the currently operating observations by deep-sea pressure gauges and Global Positioning System (GPS) buoys. The forecast capability of ship-based tsunami height measurements alone was shown to be comparable to or better than that using the existing offshore observations.

GPS water level measurements for Indonesia's Tsunami Early Warning System

NASA Astrophysics Data System (ADS)

Schöne, T.; Pandoe, W.; Mudita, I.; Roemer, S.; Illigner, J.; Zech, C.; Galas, R.

2011-03-01

On Boxing Day 2004, a severe tsunami was generated by a strong earthquake in Northern Sumatra causing a large number of casualties. At this time, neither an offshore buoy network was in place to measure tsunami waves, nor a system to disseminate tsunami warnings to local governmental entities. Since then, buoys have been developed by Indonesia and Germany, complemented by NOAA's Deep-ocean Assessment and Reporting of Tsunamis (DART) buoys, and have been moored offshore Sumatra and Java. The suite of sensors for offshore tsunami detection in Indonesia has been advanced by adding GPS technology for water level measurements. The usage of GPS buoys in tsunami warning systems is a relatively new approach. The concept of the German Indonesian Tsunami Early Warning System (GITEWS) (Rudloff et al., 2009) combines GPS technology and ocean bottom pressure (OBP) measurements. Especially for near-field installations where the seismic noise may deteriorate the OBP data, GPS-derived sea level heights provide additional information. The GPS buoy technology is precise enough to detect medium to large tsunamis of amplitudes larger than 10 cm. The analysis presented here suggests that for about 68% of the time, tsunamis larger than 5 cm may be detectable.

A global probabilistic tsunami hazard assessment from earthquake sources

USGS Publications Warehouse

Davies, Gareth; Griffin, Jonathan; Lovholt, Finn; Glimsdal, Sylfest; Harbitz, Carl; Thio, Hong Kie; Lorito, Stefano; Basili, Roberto; Selva, Jacopo; Geist, Eric L.; Baptista, Maria Ana

2017-01-01

Large tsunamis occur infrequently but have the capacity to cause enormous numbers of casualties, damage to the built environment and critical infrastructure, and economic losses. A sound understanding of tsunami hazard is required to underpin management of these risks, and while tsunami hazard assessments are typically conducted at regional or local scales, globally consistent assessments are required to support international disaster risk reduction efforts, and can serve as a reference for local and regional studies. This study presents a global-scale probabilistic tsunami hazard assessment (PTHA), extending previous global-scale assessments based largely on scenario analysis. Only earthquake sources are considered, as they represent about 80% of the recorded damaging tsunami events. Globally extensive estimates of tsunami run-up height are derived at various exceedance rates, and the associated uncertainties are quantified. Epistemic uncertainties in the exceedance rates of large earthquakes often lead to large uncertainties in tsunami run-up. Deviations between modelled tsunami run-up and event observations are quantified, and found to be larger than suggested in previous studies. Accounting for these deviations in PTHA is important, as it leads to a pronounced increase in predicted tsunami run-up for a given exceedance rate.

Warnings and reactions to the Tohoku tsunami in Hawaii

NASA Astrophysics Data System (ADS)

Houghton, B. F.; Gregg, C. E.

2012-12-01

The 2011 Tohoku tsunami was the first chance within the USA to document and interpret large-scale response and protective action behavior with regard to a large, destructive tsunami since 1964. The 2011 tsunami offered a unique, short-lived opportunity to transform our understanding of individual and collective behavior in the US in response to a well-publicized tsunami warning and, in particular, to look at the complex interplay of official information sources, informal warnings and information-seeking in communities with significant physical impact from the 2011 tsunami. This study is focused in Hawaii, which suffered significant ($30 M), but localized damage, from the 2011 Tohoku tsunami and underwent a full-scale tsunami evacuation. The survey contrasts three Hawaiian communities which either experienced significant tsunami damage (Kona) or little physical impact (Hilo, Honolulu). It also contrasts a long-established local community with experience of evacuation, destruction and loss of life in two tsunamis (Hilo) with a metropolitan population with a large visitor presence (Honolulu) that has not experienced a damaging tsunami in decades. Many factors such as personal perceptions of risk, beliefs, past exposure to the hazard, forecast uncertainty, trust in information sources, channels of transmission of information, the need for message confirmation, responsibilities, obligations, mobility, the ability to prepare, the availability of transportation and transport routes, and an acceptable evacuation center affected behavior. We provide new information on how people reacted to warnings and tsunamis, especially with regard to social integration of official warnings and social media. The results of this study will strengthen community resilience to tsunamis, working with emergency managers to integrate strengths and weaknesses of the public responses with official response plans.

Simulated tsunami inundation for a range of Cascadia megathrust earthquake scenarios at Bandon, Oregon, USA

USGS Publications Warehouse

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.

Probabilistic tsunami hazard assessment in Greece for seismic sources along the segmented Hellenic Arc

NASA Astrophysics Data System (ADS)

Novikova, Tatyana; Babeyko, Andrey; Papadopoulos, Gerassimos

2017-04-01

Greece and adjacent coastal areas are characterized by a high population exposure to tsunami hazard. The Hellenic Arc is the most active geotectonic structure for the generation of earthquakes and tsunamis. We performed probabilistic tsunami hazard assessment for selected locations of Greek coastlines which are the forecasting points officially used in the tsunami warning operations by the Hellenic National Tsunami Warning Center and the NEAMTWS/IOC/UNESCO. In our analysis we considered seismic sources for tsunami generation along the western, central and eastern segments of the Hellenic Arc. We first created a synthetic catalog as long as 10,000 years for all the significant earthquakes with magnitudes in the range from 6.0 to 8.5, the real events being included in this catalog. For each event included in the synthetic catalog a tsunami was generated and propagated using Boussinesq model. The probability of occurrence for each event was determined by Gutenberg-Richter magnitude-frequency distribution. The results of our study are expressed as hazard curves and hazard maps. The hazard curves were obtained for the selected sites and present the annual probability of exceedance as a function of pick coastal tsunami amplitude. Hazard maps represent the distribution of peak coastal tsunami amplitudes corresponding to a fixed annual probability. In such forms our results can be easily compared to the ones obtained in other studies and further employed for the development of tsunami risk management plans. This research is a contribution to the EU-FP7 tsunami research project ASTARTE (Assessment, Strategy And Risk Reduction for Tsunamis in Europe), grant agreement no: 603839, 2013-10-30.

Modeling of Grain Size Distribution of Tsunami Sand Deposits in V-shaped Valley of Numanohama During the 2011 Tohoku Tsunami

NASA Astrophysics Data System (ADS)

Gusman, A. R.; Satake, K.; Goto, T.; Takahashi, T.

2016-12-01

Estimating tsunami amplitude from tsunami sand deposit has been a challenge. The grain size distribution of tsunami sand deposit may have correlation with tsunami inundation process, and further with its source characteristics. In order to test this hypothesis, we need a tsunami sediment transport model that can accurately estimate grain size distribution of tsunami deposit. Here, we built and validate a tsunami sediment transport model that can simulate grain size distribution. Our numerical model has three layers which are suspended load layer, active bed layer, and parent bed layer. The two bed layers contain information about the grain size distribution. This numerical model can handle a wide range of grain sizes from 0.063 (4 ϕ) to 5.657 mm (-2.5 ϕ). We apply the numerical model to simulate the sedimentation process during the 2011 Tohoku earthquake in Numanohama, Iwate prefecture, Japan. The grain size distributions at 15 sample points along a 900 m transect from the beach are used to validate the tsunami sediment transport model. The tsunami deposits are dominated by coarse sand with diameter of 0.5 - 1 mm and their thickness are up to 25 cm. Our tsunami model can well reproduce the observed tsunami run-ups that are ranged from 16 to 34 m along the steep valley in Numanohama. The shapes of the simulated grain size distributions at many sample points located within 300 m from the shoreline are similar to the observations. The differences between observed and simulated peak of grain size distributions are less than 1 ϕ. Our result also shows that the simulated sand thickness distribution along the transect is consistent with the observation.

Near Source 2007 Peru Tsunami Runup Observations and Modeling

NASA Astrophysics Data System (ADS)

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.

Role of State Tsunami Geoscientists during Emergency Response Activities: Example from the State of California (USA) during September 29, 2009, Samoa Tsunami Event

NASA Astrophysics Data System (ADS)

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.

Playing against nature: improving earthquake hazard mitigation

NASA Astrophysics Data System (ADS)

Stein, S. A.; Stein, J.

2012-12-01

The great 2011 Tohoku earthquake dramatically demonstrated the need to improve earthquake and tsunami hazard assessment and mitigation policies. The earthquake was much larger than predicted by hazard models, and the resulting tsunami overtopped coastal defenses, causing more than 15,000 deaths and $210 billion damage. Hence if and how such defenses should be rebuilt is a challenging question, because the defences fared poorly and building ones to withstand tsunamis as large as March's is too expensive,. A similar issue arises along the Nankai Trough to the south, where new estimates warning of tsunamis 2-5 times higher than in previous models raise the question of what to do, given that the timescale on which such events may occur is unknown. Thus in the words of economist H. Hori, "What should we do in face of uncertainty? Some say we should spend our resources on present problems instead of wasting them on things whose results are uncertain. Others say we should prepare for future unknown disasters precisely because they are uncertain". Thus society needs strategies to mitigate earthquake and tsunami hazards that make economic and societal sense, given that our ability to assess these hazards is poor, as illustrated by highly destructive earthquakes that often occur in areas predicted by hazard maps to be relatively safe. Conceptually, we are playing a game against nature "of which we still don't know all the rules" (Lomnitz, 1989). Nature chooses tsunami heights or ground shaking, and society selects the strategy to minimize the total costs of damage plus mitigation costs. As in any game of chance, we maximize our expectation value by selecting the best strategy, given our limited ability to estimate the occurrence and effects of future events. We thus outline a framework to find the optimal level of mitigation by balancing its cost against the expected damages, recognizing the uncertainties in the hazard estimates. This framework illustrates the role of the uncertainties and the need to candidly assess them. It can be applied to exploring policies under various hazard scenarios and mitigating other natural hazards.ariation in total cost, the sum of expected loss and mitigation cost, as a function of mitigation level. The optimal level of mitigation, n*, minimizes the total cost. The expected loss depends on the hazard model, so the better the hazard model, the better the mitigation policy (Stein and Stein, 2012).

Probability-Based Design Criteria of the ASCE 7 Tsunami Loads and Effects Provisions (Invited)

NASA Astrophysics Data System (ADS)

Chock, G.

2013-12-01

Mitigation of tsunami risk requires a combination of emergency preparedness for evacuation in addition to providing structural resilience of critical facilities, infrastructure, and key resources necessary for immediate response and economic and social recovery. Critical facilities would include emergency response, medical, tsunami refuges and shelters, ports and harbors, lifelines, transportation, telecommunications, power, financial institutions, and major industrial/commercial facilities. The Tsunami Loads and Effects Subcommittee of the ASCE/SEI 7 Standards Committee is developing a proposed new Chapter 6 - Tsunami Loads and Effects for the 2016 edition of the ASCE 7 Standard. ASCE 7 provides the minimum design loads and requirements for structures subject to building codes such as the International Building Code utilized in the USA. In this paper we will provide a review emphasizing the intent of these new code provisions and explain the design methodology. The ASCE 7 provisions for Tsunami Loads and Effects enables a set of analysis and design methodologies that are consistent with performance-based engineering based on probabilistic criteria. . The ASCE 7 Tsunami Loads and Effects chapter will be initially applicable only to the states of Alaska, Washington, Oregon, California, and Hawaii. Ground shaking effects and subsidence from a preceding local offshore Maximum Considered Earthquake will also be considered prior to tsunami arrival for Alaska and states in the Pacific Northwest regions governed by nearby offshore subduction earthquakes. For national tsunami design provisions to achieve a consistent reliability standard of structural performance for community resilience, a new generation of tsunami inundation hazard maps for design is required. The lesson of recent tsunami is that historical records alone do not provide a sufficient measure of the potential heights of future tsunamis. Engineering design must consider the occurrence of events greater than scenarios in the historical record, and should properly be based on the underlying seismicity of subduction zones. Therefore, Probabilistic Tsunami Hazard Analysis (PTHA) consistent with source seismicity must be performed in addition to consideration of historical event scenarios. A method of Probabilistic Tsunami Hazard Analysis has been established that is generally consistent with Probabilistic Seismic Hazard Analysis in the treatment of uncertainty. These new tsunami design zone maps will define the coastal zones where structures of greater importance would be designed for tsunami resistance and community resilience. Structural member acceptability criteria will be based on performance objectives for a 2,500-year Maximum Considered Tsunami. The approach developed by the ASCE Tsunami Loads and Effects Subcommittee of the ASCE 7 Standard would result in the first national unification of tsunami hazard criteria for design codes reflecting the modern approach of Performance-Based Engineering.

Documentation for the Southeast Asia seismic hazard maps

USGS Publications Warehouse

Petersen, Mark; Harmsen, Stephen; Mueller, Charles; Haller, Kathleen; Dewey, James; Luco, Nicolas; Crone, Anthony; Lidke, David; Rukstales, Kenneth

2007-01-01

The U.S. Geological Survey (USGS) Southeast Asia Seismic Hazard Project originated in response to the 26 December 2004 Sumatra earthquake (M9.2) and the resulting tsunami that caused significant casualties and economic losses in Indonesia, Thailand, Malaysia, India, Sri Lanka, and the Maldives. During the course of this project, several great earthquakes ruptured subduction zones along the southern coast of Indonesia (fig. 1) causing additional structural damage and casualties in nearby communities. Future structural damage and societal losses from large earthquakes can be mitigated by providing an advance warning of tsunamis and introducing seismic hazard provisions in building codes that allow buildings and structures to withstand strong ground shaking associated with anticipated earthquakes. The Southeast Asia Seismic Hazard Project was funded through a United States Agency for International Development (USAID)—Indian Ocean Tsunami Warning System to develop seismic hazard maps that would assist engineers in designing buildings that will resist earthquake strong ground shaking. An important objective of this project was to discuss regional hazard issues with building code officials, scientists, and engineers in Thailand, Malaysia, and Indonesia. The code communities have been receptive to these discussions and are considering updating the Thailand and Indonesia building codes to incorporate new information (for example, see notes from Professor Panitan Lukkunaprasit, Chulalongkorn University in Appendix A).

Indigenous knowledge management to enhance community resilience to tsunami risk: lessons learned from Smong traditions in Simeulue island, Indonesia

NASA Astrophysics Data System (ADS)

Rahman, A.; Sakurai, A.; Munadi, K.

2017-02-01

Knowledge accumulation and production embedded in communities through social interactions meant that the Smong tradition of indigenous knowledge of tsunami risk successfully alerted people to the 2004 tsunami, on the island of Simeulue, in Aceh, Indonesia. Based on this practical example, an indigenous management model was developed for Smong information. This knowledge management method involves the transformation of indigenous knowledge into applicable ways to increase community resilience, including making appropriate decisions and taking action in three disaster phases. First, in the pre-disaster stage, the community needs to be willing to mainstream and integrate indigenous knowledge of disaster risk reduction issues into related activities. Second, during disasters, the Smong tradition should make the community able to think clearly, act based on informed decisions, and protect themselves and others by using their indigenous knowledge. Last, in the post-disaster phase, the community needs to be strong enough to face challenges and support each other and “building back better” efforts, using local resources. The findings for the Smong tradition provide valuable knowledge about community resilience. Primary community resilience to disasters is strongly related to existing knowledge that triggers appropriate decisions and actions during pre-disaster, disaster, and post-disaster phases.

Marine Debris Composition on Remote Alaskan National Park Shores

NASA Astrophysics Data System (ADS)

Pister, B.; Kunisch, E.; Polasek, L.; Bering, J.; Kim, S.; Neitlich, P.; Nicolato, K.

2016-02-01

Marine debris is a pervasive problem along coastlines around the world. The National Park Service manages approximately 3500 miles of shoreline in Alaska's national park units combined. Most of these shores are remote, difficult and expensive to access. In 2011 the Tohoku earthquake hit Japan and generated a devastating tsunami that washed an estimated 150 million tons of debris out to sea. Much of the debris washed ashore in Alaska. The tsunami brought new attention to the long standing problem of marine debris. In 2015 the National Park Service mounted a two pronged effort to remove as much debris as possible from the shores of five park units in Alaska, and initiate education programs about the issue. Almost 11,000 kg of debris were removed from the shores of: Wrangell-St. Elias National Park, Kenai Fjords National Park, Katmai National Park, Bering Land Bridge National Preserve and Cape Krusenstern National Monument. Approximately 58% of the debris was plastic. Although much of the debris resembled items expected as a result of the tsunami, a great percentage of the debris was clearly from other sources, such as fishing and shipping. Preliminary analysis suggests that debris composition varied significantly between parks, possibly from locally-derived sources. This can influence how the National Park Service creates educational outreach programs that focus on marine debris prevention exercises.

Tsunami Evidence in South Coast Java, Case Study: Tsunami Deposit along South Coast of Cilacap

NASA Astrophysics Data System (ADS)

Rizal, Yan; Aswan; Zaim, Yahdi; Dwijo Santoso, Wahyu; Rochim, Nur; Daryono; Dewi Anugrah, Suci; Wijayanto; Gunawan, Indra; Yatimantoro, Tatok; Hidayanti; Herdiyani Rahayu, Resti; Priyobudi

2017-06-01

Cilacap Area is situated in coastal area of Southern Java and directly affected by tsunami hazard in 2006. This event was triggered by active subduction in Java Trench which active since long time ago. To detect tsunami and active tectonic in Southern Java, paleo-tsunami study is performed which is targeted paleo-tsunami deposit older than fifty years ago. During 2011 - 2016, 16 locations which suspected as paleo-tsunami location were visited and the test-pits were performed to obtain characteristic and stratigraphy of paleo-tsunami layers. Paleo-tsunami layer was identified by the presence of light-sand in the upper part of paleo-soil, liquefaction fine grain sandstone, and many rip-up clast of mudstone. The systematic samples were taken and analysis (micro-fauna, grainsize and dating analysis). Micro-fauna result shows that paleo-tsunami layer consist of benthonic foraminifera assemblages from different bathymetry and mixing in one layer. Moreover, grainsize shows random grain distribution which characterized as turbulence and strong wave deposit. Paleo-tsunami layers in Cilacap area are correlated using paleo-soil as marker. There are three paleo-tsunami layers and the distribution can be identified as PS-A, PS-B and PS-C. The samples which were taken in Glempang Pasir layer are being dated using Pb - Zn (Lead-Zinc) method. The result of Pb - Zn (Lead-Zinc) dating shows that PS-A was deposited in 139 years ago, PS-B in 21 years ago, and PS C in 10 years ago. This result indicates that PS -1 occurred in 1883 earthquake activity while PS B formed in 1982 earthquake and PS-C was formed by 2006 earthquake. For ongoing research, the older paleo-tsunami layers were determined in the Gua Nagaraja, close to Selok location and 6 layers of Paleo-tsunami suspect found which shown a similar characteristic with the layers from another location. The three layers deeper approximately have an older age than another location in Cilacap.

Historical Tsunami Records on Russian Island, the Sea of Japan

NASA Astrophysics Data System (ADS)

Razjigaeva, N. G.; Ganzey, L. A.; Grebennikova, T. A.; Arslanov, Kh. A.; Ivanova, E. D.; Ganzey, K. S.; Kharlamov, A. A.

2018-04-01

In this article, we provide data evidencing tsunamis on Russian Island over the last 700 years. Reconstructions are developed based on the analyses of peat bog sections on the coast of Spokoynaya Bay, including layers of tsunami sands. Ancient beach sands under peat were deposited during the final phase of transgression of the Medieval Warm Period. We used data on diatoms and benthic foraminifers to identify the marine origin of the sands. The grain size compositions of the tsunami deposits were used to determine the sources of material carried by the tsunamis. The chronology of historical tsunamis was determined based on the radiocarbon dating of the underlying organic deposits. There was a stated difference between the deposition environments during tsunamis and large storms during the Goni (2015) and Lionrock (2016) typhoons. Tsunami deposits from 1983 and 1993 were found in the upper part of the sections. The inundation of the 1993 tsunami did not exceed 20 m or a height of 0.5 m a.m.s.l. (0.3 above high tide). The more intensive tsunami of 1983 had a run-up of 0.65 m a.m.s.l. and penetrated inland from the shoreline up to 40 m. Sand layer of tsunami 1940 extend in land up to 50 m from the present shoreline. Evidence of six tsunamis was elicited from the peat bog sections, the deposits of which are located 60 m from the modern coastal line. The deposits of strong historic tsunamis in the Japan Sea region in 1833, 1741, 1614 (or 1644), 1448, the XIV-XV century and 1341 were also identified on Russian Island. Their run-ups and inundation distances were also determined. The strong historic tsunamis appeared to be more intensive than those of the XX century, and considering the sea level drop during the Little Ice Age, the inundation distances were as large as 250 m.

Does Morphological Adjustment During Tsunami Inundation Increase Levels of Hazard?

NASA Astrophysics Data System (ADS)

Tehranirad, B.; Kirby, J. T., Jr.; Shi, F.; Grilli, S. T.

2016-12-01

Previous inundation mapping results for the US East Coast have shown that barrier islands would be among the most impacted areas during a possible tsunami. Many of these barriers are home to large population centers such as Atlantic City, NJ and Ocean City, MD. A tsunami can significantly change coastal morphology. Post-tsunami surveys have shown that large amounts of sediment can be moved in bays and estuaries by tsunami action, especially over coastal dunes. During tsunami inundation, large amounts of sediment have been eroded from sandy coasts and deposited further onshore. In some cases, sand dunes have been completely eroded by a tsunami, with the eroded sediment being deposited either onshore behind the dunes, or offshore during the rundown process. Given the potential for tsunamis to change coastal morphology, it is necessary to consider whether barrier island morphology change during inundation, if accounted for, would increase the assessment of tsunami hazard identified in the development of inundation and evacuation maps. In this presentation, we will show the results of our recent study on the morphological response of barrier islands during possible tsunamis that threaten the US East Coast. For this purpose, we have coupled the Boussinesq model FUNWAVE-TVD with a depth-averaged advection-diffusion sediment transport model and a morphology module to capture bed evolution under tsunami conditions. The model is verified in comparison to laboratory observations and to observed erosion/deposition patterns in Crescent City, CA harbor during the 2011 Tohoku-oki tsunami. We then use the model to study the effect of morphology change on predicted inundation limits for two barrier islands: the undeveloped Assateague Island, and the developed Ocean City, MD, using the tsunami sources utilized in previous hazard analysis. Our results suggest that significant bathymetric changes could be expected on a barrier island during tsunami inundation, leading to large increases in inundation areas for some of the events, particularly for smaller events where inundation without progressive dune breaching is minor.

Benchmarking on Tsunami Currents with ComMIT

NASA Astrophysics Data System (ADS)

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 agreement no 603839 (Project ASTARTE - Assessment, Strategy and Risk Reduction for Tsunamis in Europe)

Historical Tsunami Records on Russian Island, the Sea of Japan

NASA Astrophysics Data System (ADS)

Razjigaeva, N. G.; Ganzey, L. A.; Grebennikova, T. A.; Arslanov, Kh. A.; Ivanova, E. D.; Ganzey, K. S.; Kharlamov, A. A.

2018-03-01

In this article, we provide data evidencing tsunamis on Russian Island over the last 700 years. Reconstructions are developed based on the analyses of peat bog sections on the coast of Spokoynaya Bay, including layers of tsunami sands. Ancient beach sands under peat were deposited during the final phase of transgression of the Medieval Warm Period. We used data on diatoms and benthic foraminifers to identify the marine origin of the sands. The grain size compositions of the tsunami deposits were used to determine the sources of material carried by the tsunamis. The chronology of historical tsunamis was determined based on the radiocarbon dating of the underlying organic deposits. There was a stated difference between the deposition environments during tsunamis and large storms during the Goni (2015) and Lionrock (2016) typhoons. Tsunami deposits from 1983 and 1993 were found in the upper part of the sections. The inundation of the 1993 tsunami did not exceed 20 m or a height of 0.5 m a.m.s.l. (0.3 above high tide). The more intensive tsunami of 1983 had a run-up of 0.65 m a.m.s.l. and penetrated inland from the shoreline up to 40 m. Sand layer of tsunami 1940 extend in land up to 50 m from the present shoreline. Evidence of six tsunamis was elicited from the peat bog sections, the deposits of which are located 60 m from the modern coastal line. The deposits of strong historic tsunamis in the Japan Sea region in 1833, 1741, 1614 (or 1644), 1448, the XIV-XV century and 1341 were also identified on Russian Island. Their run-ups and inundation distances were also determined. The strong historic tsunamis appeared to be more intensive than those of the XX century, and considering the sea level drop during the Little Ice Age, the inundation distances were as large as 250 m.

Are inundation limit and maximum extent of sand useful for differentiating tsunamis and storms? An example from sediment transport simulations on the Sendai Plain, Japan

NASA Astrophysics Data System (ADS)

Watanabe, Masashi; Goto, Kazuhisa; Bricker, Jeremy D.; Imamura, Fumihiko

2018-02-01

We examined the quantitative difference in the distribution of tsunami and storm deposits based on numerical simulations of inundation and sediment transport due to tsunami and storm events on the Sendai Plain, Japan. The calculated distance from the shoreline inundated by the 2011 Tohoku-oki tsunami was smaller than that inundated by storm surges from hypothetical typhoon events. Previous studies have assumed that deposits observed farther inland than the possible inundation limit of storm waves and storm surge were tsunami deposits. However, confirming only the extent of inundation is insufficient to distinguish tsunami and storm deposits, because the inundation limit of storm surges may be farther inland than that of tsunamis in the case of gently sloping coastal topography such as on the Sendai Plain. In other locations, where coastal topography is steep, the maximum inland inundation extent of storm surges may be only several hundred meters, so marine-sourced deposits that are distributed several km inland can be identified as tsunami deposits by default. Over both gentle and steep slopes, another difference between tsunami and storm deposits is the total volume deposited, as flow speed over land during a tsunami is faster than during a storm surge. Therefore, the total deposit volume could also be a useful proxy to differentiate tsunami and storm deposits.

Explanation of temporal clustering of tsunami sources using the epidemic-type aftershock sequence model

USGS Publications Warehouse

Geist, Eric L.

2014-01-01

Temporal clustering of tsunami sources is examined in terms of a branching process model. It previously was observed that there are more short interevent times between consecutive tsunami sources than expected from a stationary Poisson process. The epidemic‐type aftershock sequence (ETAS) branching process model is fitted to tsunami catalog events, using the earthquake magnitude of the causative event from the Centennial and Global Centroid Moment Tensor (CMT) catalogs and tsunami sizes above a completeness level as a mark to indicate that a tsunami was generated. The ETAS parameters are estimated using the maximum‐likelihood method. The interevent distribution associated with the ETAS model provides a better fit to the data than the Poisson model or other temporal clustering models. When tsunamigenic conditions (magnitude threshold, submarine location, dip‐slip mechanism) are applied to the Global CMT catalog, ETAS parameters are obtained that are consistent with those estimated from the tsunami catalog. In particular, the dip‐slip condition appears to result in a near zero magnitude effect for triggered tsunami sources. The overall consistency between results from the tsunami catalog and that from the earthquake catalog under tsunamigenic conditions indicates that ETAS models based on seismicity can provide the structure for understanding patterns of tsunami source occurrence. The fractional rate of triggered tsunami sources on a global basis is approximately 14%.

Impacts of tides on tsunami propagation due to potential Nankai Trough earthquakes in the Seto Inland Sea, Japan

NASA Astrophysics Data System (ADS)

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.

When is a Tsunami a Mega-Tsunami?

NASA Astrophysics Data System (ADS)

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.

The 339 Years of Living Dangerously in Indonesia: Earthquakes and Tsunamis in the Indonesian Region from 1538 to 1877

NASA Astrophysics Data System (ADS)

Harris, R. A.; Major, J.

2013-05-01

Using 339 years of Dutch records of geophysical events in Indonesia and tsunami modeling, we have identified previously unknown mega-thrust earthquake sources in eastern Indonesia that caused severe devastation in the past and are likely to reoccur in the near future. Indonesia has experienced some of the most extreme geohazards known (Toba, Krakatoa, Tambora, Indian Ocean tsunami). Although most of well known events occurred in western Indonesia, historical records reveal that eastern Indonesia is actually more hazardous. Strain rates in eastern Indonesia are twice those in Sumatra and tsunamis are much more frequent. Adding to the disaster potential in Indonesia is its rapid population growth and urbanization, especially in coastal regions. When the events documented in historical records reoccur in eastern Indonesia, as they have in western Indonesia, ten times more people and assets will be in harms way. Arthur Wichmann's Die Erdbeben Des Indischen Archipels [The Earthquakes of the Indian Archipelago] (1918) documents >100 destructive earthquakes and 68 tsunamis between 1600 and 1877. The largest and best documented are the events of 1629, 1674 and 1852 in the Banda Sea region, 1770 and 1859 in the Molucca Sea region, 1820 in Makassar, 1857 in Dili, Timor, 1815 in Bali and Lombak, 1699, 1771, 1780, 1815, 1848 and 1852 in Java and 1799, 1833 and 1861 in Sumatra. All of these events caused damage over a broad region notwithstanding high seismic attenuation rates, and are associated with years of temporal and spatial clustering of earthquakes. Several tsunami are recorded with run-up heights > 15 meters. Many islands were engulfed and coastal communities washed away. The earthquakes associated with these events were felt over a region as large as the 2011 Tohoku Earthquake in Japan and were followed by decades of aftershocks. Over the past 160 years no major shallow earthquakes have struck eastern Indonesia, which is characterized as an area incapable of mega-thrust earthquakes (Heuret et al., 2012). However, during this time of relative quiescence enough tectonic strain energy has accumulated across several active faults to cause major earthquake and tsunami events, like those documented in historical records. The most vulnerable areas are the Molucca and Banda Sea regions where 65-90 mm/a of strain is accumulating along various subduction zone segments. The Java Trench area also posses a significant threat as well as long-quiet active faults in the Sulawesi region. With limited resources in Indonesia to address these issues it is imperative that mitigation strategies focus on the regions at highest risk. These strategies include 1) parameterization of the major earthquake and tsunami events documented in historical records, 2) reaching the 'last mile' in communicating risk, and 3) implementing effective mitigation strategies based on existing technologies and informed by local culture.

Far-Field Tsunami Hazard Assessment Along the Pacific Coast of Mexico by Historical Records and Numerical Simulation

NASA Astrophysics Data System (ADS)

Ortiz-Huerta, Laura G.; Ortiz, Modesto; García-Gastélum, Alejandro

2018-03-01

Historical records of the Chile (22 May 1960), Alaska (27 March 1964), and Tohoku (11 March 2011) tsunamis recorded along the Pacific Coast of Mexico are used to investigate the goodness of far-field tsunami modeling using a focal mechanism consisting in a uniform slip distribution on large thrust faults around the Pacific Ocean. The Tohoku 2011 tsunami records recorded by Deep ocean Assessment and Reporting of Tsunami (DART) stations, and at coastal tide stations, were used to validate transoceanic tsunami models applicable to the harbors of Ensenada, Manzanillo, and Acapulco on the coast of Mexico. The amplitude resulting from synthetic tsunamis originated by M w 9.3 earthquakes around the Pacific varies from 1 to 2.5 m, depending on the tsunami origin region and on the directivity due to fault orientation and waveform modification by prominent features of sea bottom relief.

Far-Field Tsunami Hazard Assessment Along the Pacific Coast of Mexico by Historical Records and Numerical Simulation

NASA Astrophysics Data System (ADS)

Ortiz-Huerta, Laura G.; Ortiz, Modesto; García-Gastélum, Alejandro

2018-04-01

Historical records of the Chile (22 May 1960), Alaska (27 March 1964), and Tohoku (11 March 2011) tsunamis recorded along the Pacific Coast of Mexico are used to investigate the goodness of far-field tsunami modeling using a focal mechanism consisting in a uniform slip distribution on large thrust faults around the Pacific Ocean. The Tohoku 2011 tsunami records recorded by Deep ocean Assessment and Reporting of Tsunami (DART) stations, and at coastal tide stations, were used to validate transoceanic tsunami models applicable to the harbors of Ensenada, Manzanillo, and Acapulco on the coast of Mexico. The amplitude resulting from synthetic tsunamis originated by M w 9.3 earthquakes around the Pacific varies from 1 to 2.5 m, depending on the tsunami origin region and on the directivity due to fault orientation and waveform modification by prominent features of sea bottom relief.

A possible space-based tsunami early warning system using observations of the tsunami ionospheric hole.

PubMed

Kamogawa, Masashi; Orihara, Yoshiaki; Tsurudome, Chiaki; Tomida, Yuto; Kanaya, Tatsuya; Ikeda, Daiki; Gusman, Aditya Riadi; Kakinami, Yoshihiro; Liu, Jann-Yenq; Toyoda, Atsushi

2016-12-01

Ionospheric plasma disturbances after a large tsunami can be detected by measurement of the total electron content (TEC) between a Global Positioning System (GPS) satellite and its ground-based receivers. TEC depression lasting for a few minutes to tens of minutes termed as tsunami ionospheric hole (TIH) is formed above the tsunami source area. Here we describe the quantitative relationship between initial tsunami height and the TEC depression rate caused by a TIH from seven tsunamigenic earthquakes in Japan and Chile. We found that the percentage of TEC depression and initial tsunami height are correlated and the largest TEC depressions appear 10 to 20 minutes after the main shocks. Our findings imply that Ionospheric TEC measurement using the existing ground receiver networks could be used in an early warning system for near-field tsunamis that take more than 20 minutes to arrive in coastal areas.

On the characteristics of landslide tsunamis

PubMed Central

Løvholt, F.; Pedersen, G.; Harbitz, C. B.; Glimsdal, S.; Kim, J.

2015-01-01

This review presents modelling techniques and processes that govern landslide tsunami generation, with emphasis on tsunamis induced by fully submerged landslides. The analysis focuses on a set of representative examples in simplified geometries demonstrating the main kinematic landslide parameters influencing initial tsunami amplitudes and wavelengths. Scaling relations from laboratory experiments for subaerial landslide tsunamis are also briefly reviewed. It is found that the landslide acceleration determines the initial tsunami elevation for translational landslides, while the landslide velocity is more important for impulsive events such as rapid slumps and subaerial landslides. Retrogressive effects stretch the tsunami, and in certain cases produce enlarged amplitudes due to positive interference. In an example involving a deformable landslide, it is found that the landslide deformation has only a weak influence on tsunamigenesis. However, more research is needed to determine how landslide flow processes that involve strong deformation and long run-out determine tsunami generation. PMID:26392615

On the characteristics of landslide tsunamis.

PubMed

Løvholt, F; Pedersen, G; Harbitz, C B; Glimsdal, S; Kim, J

2015-10-28

This review presents modelling techniques and processes that govern landslide tsunami generation, with emphasis on tsunamis induced by fully submerged landslides. The analysis focuses on a set of representative examples in simplified geometries demonstrating the main kinematic landslide parameters influencing initial tsunami amplitudes and wavelengths. Scaling relations from laboratory experiments for subaerial landslide tsunamis are also briefly reviewed. It is found that the landslide acceleration determines the initial tsunami elevation for translational landslides, while the landslide velocity is more important for impulsive events such as rapid slumps and subaerial landslides. Retrogressive effects stretch the tsunami, and in certain cases produce enlarged amplitudes due to positive interference. In an example involving a deformable landslide, it is found that the landslide deformation has only a weak influence on tsunamigenesis. However, more research is needed to determine how landslide flow processes that involve strong deformation and long run-out determine tsunami generation. © 2015 The Authors.

A possible space-based tsunami early warning system using observations of the tsunami ionospheric hole

PubMed Central

Kamogawa, Masashi; Orihara, Yoshiaki; Tsurudome, Chiaki; Tomida, Yuto; Kanaya, Tatsuya; Ikeda, Daiki; Gusman, Aditya Riadi; Kakinami, Yoshihiro; Liu, Jann-Yenq; Toyoda, Atsushi

2016-01-01

Ionospheric plasma disturbances after a large tsunami can be detected by measurement of the total electron content (TEC) between a Global Positioning System (GPS) satellite and its ground-based receivers. TEC depression lasting for a few minutes to tens of minutes termed as tsunami ionospheric hole (TIH) is formed above the tsunami source area. Here we describe the quantitative relationship between initial tsunami height and the TEC depression rate caused by a TIH from seven tsunamigenic earthquakes in Japan and Chile. We found that the percentage of TEC depression and initial tsunami height are correlated and the largest TEC depressions appear 10 to 20 minutes after the main shocks. Our findings imply that Ionospheric TEC measurement using the existing ground receiver networks could be used in an early warning system for near-field tsunamis that take more than 20 minutes to arrive in coastal areas. PMID:27905487

Observations and Modeling of the August 27, 2012 Earthquake and Tsunami affecting El Salvador and Nicaragua

NASA Astrophysics Data System (ADS)

Borrero, Jose C.; Kalligeris, Nikos; Lynett, Patrick J.; Fritz, Hermann M.; Newman, Andrew V.; Convers, Jaime A.

2014-12-01

On 27 August 2012 (04:37 UTC, 26 August 10:37 p.m. local time) a magnitude M w = 7.3 earthquake occurred off the coast of El Salvador and generated surprisingly large local tsunami. Following the event, local and international tsunami teams surveyed the tsunami effects in El Salvador and northern Nicaragua. The tsunami reached a maximum height of ~6 m with inundation of up to 340 m inland along a 25 km section of coastline in eastern El Salvador. Less severe inundation was reported in northern Nicaragua. In the far-field, the tsunami was recorded by a DART buoy and tide gauges in several locations of the eastern Pacific Ocean but did not cause any damage. The field measurements and recordings are compared to numerical modeling results using initial conditions of tsunami generation based on finite-fault earthquake and tsunami inversions and a uniform slip model.

How effective were mangroves as a defence against the recent tsunami?

PubMed

Dahdouh-Guebas, F; Jayatissa, L P; Di Nitto, D; Bosire, J O; Lo Seen, D; Koedam, N

2005-06-21

Whether or not mangroves function as buffers against tsunamis is the subject of in-depth research, the importance of which has been neglected or underestimated before the recent killer tsunami struck. Our preliminary post-tsunami surveys of Sri Lankan mangrove sites with different degrees of degradation indicate that human activity exacerbated the damage inflicted on the coastal zone by the tsunami.

Ocean-bottom pressure changes above a fault area for tsunami excitation and propagation observed by a submarine dense network

NASA Astrophysics Data System (ADS)

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 motions from near-fault pressure gauge data immediately after the earthquake occurs, in the sense of tsunami early warning systems.

Observations and Modeling of Environmental and Human Damages by the 2004 Indian Ocean tsunami

NASA Astrophysics Data System (ADS)

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 results further clarified that these damages are well explained by the calculated hydraulic force of tsunamis. This kind of analysis that integrated the observation and numerical results is important to evaluate environmental and human damages quantitatively, and to make a future disaster prevention plan.

The Study to Improve Tsunami Preparedness Education in Turkey

NASA Astrophysics Data System (ADS)

Sakamoto, Mayumi; Tanırcan, Gülüm; Kaneda, Yoshiyuki; Puskulcu, Seyhun; Kumamoto, Kunihiko

2016-04-01

Compared to its long history on disastrous earthquakes, disaster education history in Turkey is rather short. It has just started with an initiative of Disaster Preparedness Education Unit of Bogazici University (BU/DPEU) after 1999 Kocaeli Earthquake. Training modules and materials on disaster preparedness were prepared both for students, teachers and community. Regarding to the school education, the Ministry of National Education (MoNE) reformed their education plan in 2003, and disaster education became one of eight focused components for primary-middle education. In 2011-2014 MoNE had conducted "School-based Disaster Education Project" in collaboration with Japan International Cooperation Agency (JICA). The majority of the school education materials focus more on earthquake and there are very few education programs on tsunami. Within the MarDiM (Earthquake and Tsunami Disaster Mitigation in the Marmara Region and Disaster Education in Turkey) project between Turkey and Japan a multidisciplinary engineering research as well as development of disaster education, tsunami education booklet and video were newly developed in 2015. In order to investigate students' knowledge natural disasters and disaster preparedness with focus on tsunami, a questionnaire based survey was conducted. The survey aims to clarify following questions: 1) how students obtain natural disaster information, 2) how students prepare for natural disaster, 3) knowledge on tsunami (hazard mechanism, evacuation behavior, historical disaster). The study was conducted by BU/DPEU in 2015 and 375 students answered the questionnaire. Results showed that students have more interest on earthquake, flood, tsunami and landslide followed it. Most students have heard about tsunami and the school is a key resource of their information. They know relatively well about tsunami mechanism, however, they have less knowledge on tsunami evacuation behavior and tsunami history in Turkey. In order to let students have more knowledge on tsunami, tsunami class was provided by BU/DPEU using tsunami booklet and videos. The class was evaluated by before/after class tests and the result showed improvement on students' knowledge. The result showed the necessity to integrate tsunami education materials in school disaster education curriculum.

Modelling of historical tsunami in Eastern Indonesia: 1674 Ambon and 1992 Flores case studies

NASA Astrophysics Data System (ADS)

Pranantyo, Ignatius Ryan; Cummins, Phil; Griffin, Jonathan; Davies, Gareth; Latief, Hamzah

2017-07-01

In order to reliably assess tsunami hazard in eastern Indonesia, we need to understand how historical events were generated. Here we consider two such events: the 1674 Ambon and the 1992 Flores tsunamis. Firstly, Ambon Island suffered a devastating earthquake that generated a tsunami with 100 m run-up height on the north coast of the island in 1674. However, there is no known active fault around the island capable of generating such a gigantic wave. Rumphius' report describes that the initial wave was coming from three villages that collapsed immediately after the earthquake with width as far as a musket shot. Moreover, a very high tsunami was only observed locally. We suspect that a submarine landslide was the main cause of the gigantic tsunami on the north side of Ambon Island. Unfortunately, there is no data available to confirm if landslide have occurred in this region. Secondly, several tsunami source models for the 1992 Flores event have been suggested. However, the fault strike is quite different compare to the existing Flores back-arc thrust and has not been well validated against a tide gauge waveform at Palopo, Sulawesi. We considered a tsunami model based on Griffin, et al., 2015, extended with high resolution bathymetry laround Palopo, in order to validate the latest tsunami source model available. In general, the model produces a good agreement with tsunami waveforms, but arrives 10 minutes late compared to observed data. In addition, the source overestimates the tsunami inundation west of Maumere, and does not account for the presumed landslide tsunami on the east side of Flores Island.

Impact of huge tsunami in March 2011 on seaweed bed distributions in Shizugawa Bay, Sanriku Coast, revealed by remote sensing

NASA Astrophysics Data System (ADS)

Sakamoto, Shingo X.; Sasa, Shuji; Sawayama, Shuhei; Tsujimoto, Ryo; Terauchi, Genki; Yagi, Hiroshi; Komatsu, Teruhisa

2012-10-01

Seaweed beds are very important for abalones and sea urchins as a habitat. In Sanriku Coast, these animals are target species of coastal fisheries. The huge tsunami hit Sanriku Coast facing Pacific Ocean on 11 March 2011. It is needed for fishermen to know present situation of seaweed beds and understand damages of the huge tsunami on natural environments to recover coastal fisheries. We selected Shizugawa Bay as a study site because abalone catch of Shizugawa Bay occupied the first position in Sanriku Coast. To evaluate impact of tsunami on seaweed beds, we compared high spatial resolution satellite image of Shizugawa Bay before the tsunami with that after the tsunami by remote sensing with ground surveys to know impact of the tsunami on seaweed beds. We used two multi-band imageries of commercial high-resolution satellite, Geoeye-1, which were taken on 4 November 2009 before the tsunami and on 22 February 2012 after the tsunami. Although divers observed the tsunami damaged a very small part of Eisenia bicyclis distributions on rock substrates at the bay head, it was not observed clearly by satellite image analysis. On the other hand, we found increase in seaweed beds after the tsunami from the image analysis. The tsunami broke concrete breakwaters, entrained a large amount of rocks and pebble from land to the sea, and disseminated them in the bay. Thus, hard substrates suitable for attachment of seaweeds were increased. Ground surveys revealed that seaweeds consisting of E. bicyclis, Sargassum and Laminaria species grew on these hard substrates on the sandy bottom.

Kuril Islands tsunami of November 2006: 1. Impact at Crescent City by distant scattering

NASA Astrophysics Data System (ADS)

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.

Earthquake mechanism and seafloor deformation for tsunami generation

USGS Publications Warehouse

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.

Development of new tsunami detection algorithms for high frequency radars and application to tsunami warning in British Columbia, Canada

NASA Astrophysics Data System (ADS)

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 directions. A model simulating the radar backscattered signal in space and time as a function of simulated tsunami currents is applied to the sweep area. Numerical experiments show that the new algorithm can detect a realistic tsunami further offshore than a direct detection method. Correlation thresholds for tsunami detection will be derived from the results.

Tsunami Simulators in Physical Modelling - Concept to Practical Solutions

NASA Astrophysics Data System (ADS)

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 Simulators therefore focussed on the influence of multiple buildings (up to 4 rows) which showed (for instance) that the greatest forces can act on the landward (not seaward) rows of buildings. Studies in the 70m long, 4m wide main channel of the Fast Flow Facility on tsunami defence structures have also measured forces on buildings in the lee of a failed defence wall and tsunami induced scour. Supporting presentations at this conference: McGovern et al on tsunami induced scour at coastal structures and Foster et al on building loads.

Tsunami hazard maps of spanish coast at national scale from seismic sources

NASA Astrophysics Data System (ADS)

Aniel-Quiroga, Íñigo; González, Mauricio; Álvarez-Gómez, José Antonio; García, Pablo

2017-04-01

Tsunamis are a moderately frequent phenomenon in the NEAM (North East Atlantic and Mediterranean) region, and consequently in Spain, as historic and recent events have affected this area. I.e., the 1755 earthquake and tsunami affected the Spanish Atlantic coasts of Huelva and Cadiz and the 2003 Boumerdés earthquake triggered a tsunami that reached Balearic island coast in less than 45 minutes. The risk in Spain is real and, its population and tourism rate makes it vulnerable to this kind of catastrophic events. The Indian Ocean tsunami in 2004 and the tsunami in Japan in 2011 launched the worldwide development and application of tsunami risk reduction measures that have been taken as a priority in this field. On November 20th 2015 the directive of the Spanish civil protection agency on planning under the emergency of tsunami was presented. As part of the Spanish National Security strategy, this document specifies the structure of the action plans at different levels: National, regional and local. In this sense, the first step is the proper evaluation of the tsunami hazard at National scale. This work deals with the assessment of the tsunami hazard in Spain, by means of numerical simulations, focused on the elaboration of tsunami hazard maps at National scale. To get this, following a deterministic approach, the seismic structures whose earthquakes could generate the worst tsunamis affecting the coast of Spain have been compiled and characterized. These worst sources have been propagated numerically along a reconstructed bathymetry, built from the best resolution available data. This high-resolution bathymetry was joined with a 25-m resolution DTM, to generate continuous offshore-onshore space, allowing the calculation of the flooded areas prompted by each selected source. The numerical model applied for the calculation of the tsunami propagations was COMCOT. The maps resulting from the numerical simulations show not only the tsunami amplitude at coastal areas but also the run-up and inundation length from the coastline. The run-up has been calculated with numerical model, complemented with an alternative method, based on interpolation on a tsunami run-up database created ad hoc. These estimated variables allow the identification of the most affected areas in case of tsunami and they are also the base for the local authorities to evaluate the necessity of new higher resolution studies at local scale on specific areas.

Earthquake and Tsunami planning, outreach and awareness in Humboldt County, California

NASA Astrophysics Data System (ADS)

Ozaki, V.; Nicolini, T.; Larkin, D.; Dengler, L.

2008-12-01

Humboldt County has the longest coastline in California and is one of the most seismically active areas of the state. It is at risk from earthquakes located on and offshore and from tsunamis generated locally from faults associated with the Cascadia subduction zone (CSZ), other regional fault systems, and from distant sources elsewhere in the Pacific. In 1995 the California Division of Mines and Geology published the first earthquake scenario to include both strong ground shaking effects and a tsunami. As a result of the scenario, the Redwood Coast Tsunami Work Group (RCTWG), an organization of representatives from government agencies, tribes, service groups, academia and the private sector from the three northern coastal California counties, was formed in 1996 to coordinate and promote earthquake and tsunami hazard awareness and mitigation. The RCTWG and its member agencies have sponsored a variety of projects including education/outreach products and programs, tsunami hazard mapping, signage and siren planning, and has sponsored an Earthquake - Tsunami Education Room at the Humboldt County fair for the past eleven years. Three editions of Living on Shaky Ground an earthquake-tsunami preparedness magazine for California's North Coast, have been published since 1993 and a fourth is due to be published in fall 2008. In 2007, Humboldt County was the first region in the country to participate in a tsunami training exercise at FEMA's Emergency Management Institute in Emmitsburg, MD and the first area in California to conduct a full-scale tsunami evacuation drill. The County has conducted numerous multi-agency, multi-discipline coordinated exercises using county-wide tsunami response plan. Two Humboldt County communities were recognized as TsunamiReady by the National Weather Service in 2007. Over 300 tsunami hazard zone signs have been posted in Humboldt County since March 2008. Six assessment surveys from 1993 to 2006 have tracked preparedness actions and personal awareness of earthquake and tsunami hazards in the county and additional surveys have tracked public awareness and tourist concerns about tsunami hazard signs. Over the thirteen year period covered by the surveys, the percent with houses secured to foundations has increased from 58 to 80 percent, respondents aware of a local tsunami hazard increased from 51 to 73 percent and knowing what the Cascadia subduction zone is from 16 to 42 percent.

Assessment of source probabilities for potential tsunamis affecting the U.S. Atlantic coast

USGS Publications Warehouse

Geist, E.L.; Parsons, T.

2009-01-01

Estimating the likelihood of tsunamis occurring along the U.S. Atlantic coast critically depends on knowledge of tsunami source probability. We review available information on both earthquake and landslide probabilities from potential sources that could generate local and transoceanic tsunamis. Estimating source probability includes defining both size and recurrence distributions for earthquakes and landslides. For the former distribution, source sizes are often distributed according to a truncated or tapered power-law relationship. For the latter distribution, sources are often assumed to occur in time according to a Poisson process, simplifying the way tsunami probabilities from individual sources can be aggregated. For the U.S. Atlantic coast, earthquake tsunami sources primarily occur at transoceanic distances along plate boundary faults. Probabilities for these sources are constrained from previous statistical studies of global seismicity for similar plate boundary types. In contrast, there is presently little information constraining landslide probabilities that may generate local tsunamis. Though there is significant uncertainty in tsunami source probabilities for the Atlantic, results from this study yield a comparative analysis of tsunami source recurrence rates that can form the basis for future probabilistic analyses.

Tsunami Preparedness Along the U.S. West Coast (video)

USGS Publications Warehouse

Filmed and edited by: Loeffler, Kurt; Gesell, Justine

2010-01-01

Tsunamis are a constant threat to the coasts of our world. Although tsunamis are infrequent along the West coast of the United States, it is possible and necessary to prepare for potential tsunami hazards to minimize loss of life and property. Community awareness programs are important, as they strive to create an informed society by providing education and training. This video about tsunami preparedness along the West coast distinguishes between a local tsunami and a distant event and focuses on the specific needs of each region. It offers guidelines for correct tsunami response and community preparedness from local emergency managers, first-responders, and leading experts on tsunami hazards and warnings, who have been working on ways of making the tsunami affected regions safer for the people and communities on a long-term basis. This video was produced by the US Geological Survey (USGS) in cooperation with the California Emergency Management Agency (CalEMA), Oregon Department of Geology and Mineral Industries (DOGAMI), Washington Emergency Management Division (EMD), Marin Office of Emergency Services, and Pacific Gas and Electric (PG&E).

The tsunami source area of the 2003 Tokachi-oki earthquake estimated from tsunami travel times and its relationship to the 1952 Tokachi-oki earthquake

USGS Publications Warehouse

Hirata, K.; Tanioka, Y.; Satake, K.; Yamaki, S.; Geist, E.L.

2004-01-01

We estimate the tsunami source area of the 2003 Tokachi-oki earthquake (Mw 8.0) from observed tsunami travel times at 17 Japanese tide gauge stations. The estimated tsunami source area (???1.4 ?? 104 km2) coincides with the western-half of the ocean-bottom deformation area (???2.52 ?? 104 km2) of the 1952 Tokachi-oki earthquake (Mw 8.1), previously inferred from tsunami waveform inversion. This suggests that the 2003 event ruptured only the western-half of the 1952 rupture extent. Geographical distribution of the maximum tsunami heights in 2003 differs significantly from that of the 1952 tsunami, supporting this hypothesis. Analysis of first-peak tsunami travel times indicates that a major uplift of the ocean-bottom occurred approximately 30 km to the NNW of the mainshock epicenter, just above a major asperity inferred from seismic waveform inversion. Copyright ?? The Society of Geomagnetism and Earth, Planetary and Space Sciences (SGEPSS); The Seismological Society of Japan; The Volcanological Society of Japan; The Geodetic Society of Japan; The Japanese Society for Planetary Sciences.

Tsunami runup and tide-gauge observations from the 14 November 2016 M7.8 Kaikōura earthquake, New Zealand

NASA Astrophysics Data System (ADS)

Power, William; Clark, Kate; King, Darren N.; Borrero, Jose; Howarth, Jamie; Lane, Emily M.; Goring, Derek; Goff, James; Chagué-Goff, Catherine; Williams, James; Reid, Catherine; Whittaker, Colin; Mueller, Christof; Williams, Shaun; Hughes, Matthew W.; Hoyle, Jo; Bind, Jochen; Strong, Delia; Litchfield, Nicola; Benson, Adrian

2017-07-01

The 2016 M w 7.8 Kaikōura earthquake was one of the largest earthquakes in New Zealand's historical record, and it generated the most significant local source tsunami to affect New Zealand since 1947. There are many unusual features of this earthquake from a tsunami perspective: the epicentre was well inland of the coast, multiple faults were involved in the rupture, and the greatest tsunami damage to residential property was far from the source. In this paper, we summarise the tectonic setting and the historical and geological evidence for past tsunamis on this coast, then present tsunami tide gauge and runup field observations of the tsunami that followed the Kaikōura earthquake. For the size of the tsunami, as inferred from the measured heights, the impact of this event was relatively modest, and we discuss the reasons for this which include: the state of the tide at the time of the earthquake, the degree of co-seismic uplift, and the nature of the coastal environment in the tsunami source region.

Housing reconstruction in disaster recovery: a study of fishing communities post-tsunami in chennai, India.

PubMed

Raju, Emmanuel

2013-04-03

Disaster recovery after the Indian Ocean tsunami in 2004 led to a number of challenges and raised issues concerning land rights and housing reconstruction in the affected countries. This paper discusses the resistance to relocation of fishing communities in Chennai, India. Qualitative research methods were used to describe complexities in the debate between the state and the community regarding relocation, and the paper draws attention to the dimensions of the state-community interface in the recovery process. The results of this study highlight the effects of differences in the values held by each of the stakeholders regarding relocation, the lack of community participation, and thereby the interfaces that emerge between the state and the community regarding relocation. The failure to establish a nexus between disaster recovery and the importance of a sustainable livelihood for fishing communities severely delayed housing reconstruction.

Heterogeneous Structure and Seismicity beneath the Tokyo Metropolitan Area

NASA Astrophysics Data System (ADS)

Nakagawa, S.; Kato, A.; Sakai, S.; Nanjo, K.; Panayotopoulos, Y.; Kurashimo, E.; Obara, K.; Kasahara, K.; Aketagawa, T.; Kimura, H.; Hirata, N.

2010-12-01

Beneath the Tokyo metropolitan area, the Philippine Sea Plate (PSP) subducts and causes damaged mega-thrust earthquakes. Sato et al. (2005) revealed the geometry of upper surface of PSP, and Hagiwara et al. (2006) estimated the velocity structure beneath Boso peninsula. However, these results are not sufficient for the assessment of the entire picture of the seismic hazards beneath the Tokyo metropolitan area including those due to an intra-slab M7+ earthquake. So, we launched the Special Project for Earthquake Disaster Mitigation in the Tokyo Metropolitan area (Hirata et al., 2009). Proving the more detailed geometry and physical properties (e.g. velocities, densities, attenuation) and stress field within PSP is very important to attain this issue. The core item of this project is a dense seismic array called Metropolitan Seismic Observation network (MeSO-net) for making observations in the metropolitan area (Sakai and Hirata, 2009; Kasahara et al., 2009). We deployed the 249 seismic stations with a spacing of 5 km. Some parts of stations construct 5 linear arrays at interval of 2 km such as Tsukuba-Fujisawa (TF) array, etc. The TF array runs from northeast to southwest through the center of Tokyo. In this study, we applied the tomography method to image the heterogeneous structure under the Tokyo metropolitan area. We selected events from the Japan Meteorological Agency (JMA) unified earthquake list. All data of MeSO-net were edited into event data by the selected JMA unified earthquake list. We picked the P and S wave arrival times. The total number of stations and events are 421 and 1,256, respectively. Then, we applied the double-difference tomography method (Zhang and Thurber, 2003) to this dataset and estimated the fine-scale velocity structure. The grid nodes locate 10 km interval in parallel with the array, 20 km interval in perpendicular to the array; and on depth direction, 5 km interval to a depth of less than 50 km and 10 km interval at a depth of more. We used 158,930 (P wave) and 149,308 (S wave) absolute arrival times, and 374,072 (P wave) and 354,912 (S wave) differential travel times. The initial velocity structure is the JMA2001 (Ueno et al., 2001), and the Vp/Vs ratio is set to 1.73 for all grid nodes. We imaged the subducting PSP and Pacific Plate clearly. The depth section of P-wave velocity structure along the TF array clearly shows that thin low-velocity layer which overlies high-velocity layer subducts towards northeast. This low-velocity layer corresponds to the oceanic crust of the subducting PSP. The obtained tomograms combined with seismicity and focal mechanisms indicate that the interior of the subducting PSP is characterized by heterogeneous structures, which could exert a profound influence on the genesis of intra-slab earthquakes. Acknowledgement: This study was supported by the Earthquake Research Institute cooperative research program.

The Chile tsunami of 27 February 2010: Field survey and modeling

NASA Astrophysics Data System (ADS)

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

On 27 February, 2010 a magnitude Mw 8.8 earthquake occurred off the coast of Chile's Maule region some 100 km N of Concepción, causing substantial damage and loss of life on Chile's mainland and the Juan Fernandez archipelago. The majority of the 521 fatalities are attributed to the earthquake, while the tsunami accounts for 124 victims. Fortunately, ancestral knowledge from past tsunamis such as the giant 1960 event, as well as tsunami education and evacuation exercises prompted most coastal residents to spontaneously evacuate to high ground after the earthquake. The majority of the tsunami victims were tourists staying overnight in low lying camp grounds along the coast. A multi-disciplinary international tsunami survey team (ITST) was deployed within days of the event to document flow depths, runup heights, inundation distances, sediment deposition, damage patterns at various scales, performance of the man-made infrastructure and impact on the natural environment. The 3 to 25 March ITST covered an 800 km stretch of coastline from Quintero to Mehuín in various subgroups the Pacific Islands of Santa María, Juan Fernández Archipelago, and Rapa Nui (Easter), while Mocha Island was surveyed 21 to 23 May, 2010. The collected survey data includes more than 400 tsunami runup and flow depth measurements. The tsunami impact peaked with a localized maximum runup of 29 m on a coastal bluff at Constitución and 23 m on marine terraces on Mocha Island. A significant variation in tsunami impact was observed along Chile's mainland both at local and regional scales. Inundation and damage also occurred several kilometres inland along rivers. Eyewitness tsunami videos are analysed and flooding velocities presented. Observations from the Chile tsunami are compared against the 1960 Chile, 2004 Indian Ocean and 2011 Tohoku Japan tsunamis. The tsunamigenic seafloor displacements were partially characterized based on coastal uplift measurements along a 100 km stretch of coastline 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.

Performance Comparison of NAMI DANCE and FLOW-3D® Models in Tsunami Propagation, Inundation and Currents using NTHMP Benchmark Problems

NASA Astrophysics Data System (ADS)

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.

Simulation-Based Probabilistic Tsunami Hazard Analysis: Empirical and Robust Hazard Predictions

NASA Astrophysics Data System (ADS)

De Risi, Raffaele; Goda, Katsuichiro

2017-08-01

Probabilistic tsunami hazard analysis (PTHA) is the prerequisite for rigorous risk assessment and thus for decision-making regarding risk mitigation strategies. This paper proposes a new simulation-based methodology for tsunami hazard assessment for a specific site of an engineering project along the coast, or, more broadly, for a wider tsunami-prone region. The methodology incorporates numerous uncertain parameters that are related to geophysical processes by adopting new scaling relationships for tsunamigenic seismic regions. Through the proposed methodology it is possible to obtain either a tsunami hazard curve for a single location, that is the representation of a tsunami intensity measure (such as inundation depth) versus its mean annual rate of occurrence, or tsunami hazard maps, representing the expected tsunami intensity measures within a geographical area, for a specific probability of occurrence in a given time window. In addition to the conventional tsunami hazard curve that is based on an empirical statistical representation of the simulation-based PTHA results, this study presents a robust tsunami hazard curve, which is based on a Bayesian fitting methodology. The robust approach allows a significant reduction of the number of simulations and, therefore, a reduction of the computational effort. Both methods produce a central estimate of the hazard as well as a confidence interval, facilitating the rigorous quantification of the hazard uncertainties.

Preliminary investigation of the hazard faced by Western Australia from tsunami generated along the Sunda Arc

NASA Astrophysics Data System (ADS)

Burbidge, D.; Cummins, P. R.

2005-12-01

Since the Boxing Day tsunami various countries surrounding the Indian Ocean have been investigating the potential hazard from trans-Indian Ocean tsunami generated along the Sunda Arc, south of Indonesia. This study presents some preliminary estimates of the tsunami hazard faced by Western Australia from tsunami generated along the Arc. To estimate the hazard, a suite of tsunami spaced evenly along the subduction zone to the south of Indonesia were numerically modelled. Offshore wave heights from tsunami generated in this region are significantly higher along northwestern part of the Western Australian coast from Exmouth to the Kimberly than they are along the rest of the coast south of Exmouth. Due to the offshore bathymetry, the area around Onslow in particular may face a higher tsunami than other areas the West Australian coast. Earthquakes between Java and Timor are likely to produce the greatest hazard to northwest WA. Earthquakes off Sumatra are likely the main source of tsunami hazard to locations south of Exmouth, however the hazard here is likely to be lower than that along the north western part of the West Australian coast. Tsunami generated by other sources (eg large intra-plate events, volcanoes, landslides and asteroids) could threaten other parts of the coast.

Distribution and sedimentary characteristics of tsunami deposits along the Cascadia margin of western North America

USGS Publications Warehouse

Peters, R.; Jaffe, B.; Gelfenbaum, G.

2007-01-01

Tsunami deposits have been found at more than 60 sites along the Cascadia margin of Western North America, and here we review and synthesize their distribution and sedimentary characteristics based on the published record. Cascadia tsunami deposits are best preserved, and most easily identified, in low-energy coastal environments such as tidal marshes, back-barrier marshes and coastal lakes where they occur as anomalous layers of sand within peat and mud. They extend up to a kilometer inland in open coastal settings and several kilometers up river valleys. They are distinguished from other sediments by a combination of sedimentary character and stratigraphic context. Recurrence intervals range from 300-1000??years with an average of 500-600??years. The tsunami deposits have been used to help evaluate and mitigate tsunami hazards in Cascadia. They show that the Cascadia subduction zone is prone to great earthquakes that generate large tsunamis. The inclusion of tsunami deposits on inundation maps, used in conjunction with results from inundation models, allows a more accurate assessment of areas subject to tsunami inundation. The application of sediment transport models can help estimate tsunami flow velocity and wave height, parameters which are necessary to help establish evacuation routes and plan development in tsunami prone areas. ?? 2007.

The Solomon Islands Tsunami of 6 February 2013 in the Santa Cruz Islands: Field Survey and Modeling

NASA Astrophysics Data System (ADS)

Fritz, Hermann M.; Papantoniou, Antonios; Biukoto, Litea; Albert, Gilly; Wei, Yong

2014-05-01

On February 6, 2013 at 01:12:27 UTC (local time: UTC+11), a magnitude Mw 8.0 earthquake occurred 70 km to the west of Ndendo Island (Santa Cruz Island) in the Solomon Islands. The under-thrusting earthquake near a 90° bend, where the Australian plate subducts beneath the Pacific plate generated a locally focused tsunami in the Coral Sea and the South Pacific Ocean. The tsunami claimed the lives of 10 people and injured 15, destroyed 588 houses and partially damaged 478 houses, affecting 4,509 people in 1,066 households corresponding to an estimated 37% of the population of Santa Cruz Island. A multi-disciplinary international tsunami survey team (ITST) was deployed within days of the event to document flow depths, runup heights, inundation distances, sediment and coral boulder depositions, land level changes, damage patterns at various scales, performance of the man-made infrastructure and impact on the natural environment. The 19 to 23 February 2013 ITST covered 30 locations on 4 Islands: Ndendo (Santa Cruz), Tomotu Noi (Lord Howe), Nea Tomotu (Trevanion, Malo) and Tinakula. The reconnaissance completely circling Ndendo and Tinakula logged 240 km by small boat and additionally covered 20 km of Ndendo's hard hit western coastline by vehicle. The collected survey data includes more than 80 tsunami runup and flow depth measurements. The tsunami impact peaked at Manoputi on Ndendo's densely populated west coast with maximum tsunami height exceeding 11 m and local flow depths above ground exceeding 7 m. A fast tide-like positive amplitude of 1 m was recorded at Lata wharf inside Graciosa Bay on Ndendo Island and misleadingly reported in the media as representative tsunami height. The stark contrast between the field observations on exposed coastlines and the Lata tide gauge recording highlights the importance of rapid tsunami reconnaissance surveys. Inundation distance and damage more than 500 m inland were recorded at Lata airport on Ndendo Island. Landslides were observed on volcanic Tinakula Island and on Ndendo Island. Observations from the 2013 Santa Cruz tsunami are compared against the 2007 and 2010 Solomon Islands tsunamis. The field observations in the Santa Cruz Islands present an important dataset to assess tsunami impact in the near-source region. The tsunami was also recorded at deep-ocean tsunameters and tide gauges throughout the Pacific. These observations allow us to further investigate the physics of tsunami generation caused by the seismic process (or other non-seismic mechanisms). We use numerical model MOST to analyze the large runup and complex impact distribution caused by the Santa Cruz tsunami. Source models obtained using seismic data / tsunami data are carried out to initialize the tsunami model. MOST uses two sets of numerical grids to investigate both the near- and far-field aspects of the tsunami. The basin-scale modeling results are computed using a spatial resolution of 4 arc min (approx. 7,200 m) and compared with measurements at deep-ocean tsunameters. The near-field modeling is carried out using a series of telescoped grids up to a grid resolution of tens of meters to compare with the tsunami runup and flooding extent obtained through the field survey in the Solomon Islands. The modeling results emphasize the contrast between the tsunami impact on the exposed coastline and the sheltered Lata Bay stressing the problematic interpretation of a tsunami in progress based solely on near-source tide-gauge measurements. The team also interviewed eyewitnesses and educated residents about the tsunami hazard in numerous ad hoc presentations and discussions. The combination of ancestral knowledge and recent Solomon Islands wide geohazards education programs triggered an immediate spontaneous self-evacuation containing the death toll in the small evacuation window of few minutes between the end of the ground shaking and the onslaught of the tsunami. Fortunately school children were shown a video on the 1 April 2007 Solomon Islands tsunami 3 months prior to the Santa Cruz event and the headmaster of the school at Venga evacuated the later flooded school already during a foreshock. On Tomotu Noi Island at Bamoi the residents evacuated inland towards a crocodile infested lake, which was not reached by the tsunami inundation. Community-based education and awareness programs are particularly essential to help save lives in locales at risk from near-source tsunamis.

Variations in City Exposure and Sensitivity to Tsunami Hazards in Oregon

USGS Publications Warehouse

Wood, Nathan

2007-01-01

Evidence of past events and modeling of potential future events suggest that tsunamis are significant threats to Oregon coastal communities. Although a potential tsunami-inundation zone from a Cascadia Subduction Zone earthquake has been delineated, what is in this area and how communities have chosen to develop within it have not been documented. A vulnerability assessment using geographic-information-system tools was conducted to describe tsunami-prone landscapes on the Oregon coast and to document city variations in developed land, human populations, economic assets, and critical facilities relative to the tsunami-inundation zone. Results indicate that the Oregon tsunami-inundation zone contains approximately 22,201 residents (four percent of the total population in the seven coastal counties), 14,857 employees (six percent of the total labor force), and 53,714 day-use visitors on average every day to coastal Oregon State Parks within the tsunami-inundation zone. The tsunami-inundation zone also contains 1,829 businesses that generate approximately $1.9 billion in annual sales volume (seven and five percent of study-area totals, respectively) and tax parcels with a combined total value of $8.2 billion (12 percent of the study-area total). Although occupancy values are not known for each facility, the tsunami-inundation zone also contains numerous dependent-population facilities (for example, adult-residential-care facilities, child-day-care facilities, and schools), public venues (for example, religious organizations and libraries), and critical facilities (for example, police stations). Racial diversity of residents in the tsunami-inundation zone is low, with 96 percent identifying themselves as White, either alone or in combination with one or more race. Twenty-two percent of the residents in the tsunami-inundation zone are over 65 years in age, 36 percent of the residents live on unincorporated county lands, and 37 percent of the households are renter occupied. The employee population in the tsunami-inundation zone is largely in accommodation and food services, retail trade, manufacturing, and arts and entertainment sectors. Results indicate that vulnerability, described here by exposure (the amount of assets in tsunami-prone areas) and sensitivity (the relative percentage of assets in tsunami-prone areas) varies considerably among 26 incorporated cities in Oregon. City exposure and sensitivity to tsunami hazards is highest in the northern portion of the coast. The City of Seaside in Clatsop County has the highest exposure, the highest sensitivity, and the highest combined relative exposure and sensitivity to tsunamis. Results also indicate that the amount of city assets in tsunami-prone areas is weakly related to the amount of a community's land in this zone; the percentage of a city's assets, however, is strongly related to the percentage of its land that is in the tsunami-prone areas. This report will further the dialogue on societal risk to tsunami hazards in Oregon and help identify future preparedness, mitigation, response, and recovery planning needs within coastal cities and economic sectors of the state of Oregon.

Sediments from the Boxing Day tsunami on the coasts of southeastern India and Kenya

NASA Astrophysics Data System (ADS)

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-inland trend could be identified in the thinning- inland sand layer. Benthic foraminifera also indicate an entrainment of sediment by the incoming tsunami wave in a water depth less than 30 m, however there are indications that sediment might be entrained in a water depth of 80 m. The fact that only one sand layer occurs in Kenya as opposed to three at Tamil Nadu might lead to the conclusion that only one wave approached the Kenyan coast. This interpretation is misleading because the Kenyan coast is several thousand kilometers away from source area of the tsunami; the non-linear behavior of the incoming tsunami waves, especially the interaction with the nearby reef, may have resulted in the discovered sedimentologic evidence of the tsunami impact on the Kenyan coast.

Numerical reconstruction of tsunami source using combined seismic, satellite and DART data

NASA Astrophysics Data System (ADS)

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 function, the adjoint problem is solved. The conservative finite-difference schemes for solving the direct and adjoint problems in the approximation of shallow water are constructed. Results of numerical experiments of the tsunami source reconstruction are presented and discussed. We show that using a combination of three different types of data allows one to increase the stability and efficiency of tsunami source reconstruction. Non-profit organization WAPMERR (World Agency of Planetary Monitoring and Earthquake Risk Reduction) in collaboration with Informap software development department developed the Integrated Tsunami Research and Information System (ITRIS) to simulate tsunami waves and earthquakes, river course changes, coastal zone floods, and risk estimates for coastal constructions at wave run-ups and earthquakes. The special scientific plug-in components are embedded in a specially developed GIS-type graphic shell for easy data retrieval, visualization and processing. This work was supported by the Russian Foundation for Basic Research (project No. 12-01-00773 'Theory and Numerical Methods for Solving Combined Inverse Problems of Mathematical Physics') and interdisciplinary project of SB RAS 14 'Inverse Problems and Applications: Theory, Algorithms, Software'.

Testing the Australian Megatsunami Hypothesis

NASA Astrophysics Data System (ADS)

Courtney, Claire; Strotz, Luke; Chague-Goff, Catherine; Goff, James; Dominey-Howes, Dale

2010-05-01

In the wake of the 2004 Indian Ocean Tsunami, many countries have been forced to reassess the risk of tsunamis to their coasts. Australia, with relative tectonic stability, has previously been considered at low risk of tsunami inundation. Within written history, only small tsunamis have struck the Australian coast, causing little damage. However, a body of work has arisen that sheds doubt on this apparent low risk, with researchers suggesting that megatsunamis have affected the east Australian coast, in particular southern New South Wales. With proposed run-ups in excess of 100m, recurrence of such megatsunamis in the now densely populated New South Wales coastal region would be catastrophic. The disjunct between historical and geological records demands a thorough re-evaluation of New South Wales sites purported to contain evidence of megatsunamis. In addition, the unique set of diagnostic criteria previously used to identify Australian palaeotsunami deposits is distinctly different to criteria applied to paleotsunamis globally. To address these issues, four coastal lagoonal sites in southern New South Wales were identified for further investigation. In addition to paleotsunami investigation, these sites were selected to provide a geological record of significant events during the Holocene. Site selection was based on small accommodation space and a high preservation potential with back barrier depressions closed to the sea. A suite of diagnostic criteria developed over the past two decades to identify palaeotsunamis have been applied to cores extracted from these sites. Methods used include sedimentary description, grain size analysis, micropalaeontology, geochemistry and a variety of dating techniques such as radiocarbon and lead 210. Preliminary analysis of these results will be presented, with particular focus on sites where there is evidence that could indicate catastrophic saltwater inundation.

Insights on the 1990 Bohol Tsunamigenic Earthquake, Bohol Island, Philippines

NASA Astrophysics Data System (ADS)

Besana, G. M.; Daligdig, J. A.; Abigania, M. T.; Talisic, J. E.; Evangelista, N.

2004-12-01

The February 8, 1990 earthquake at Bohol area is one of the few strong earthquakes that have affected central Philippines since the early 1900's. This M6.0 1990 Bohol event nonetheless wrought havoc to at least 16 municipalities, caused numerous casualties, injured about three hundred people, rendered several thousand homeless and evacuated from the coastal areas, and damaged at least P154 million worth of properties. The epicenter of this earthquake was initially placed onshore at 17km east of Tagbilaran City and was attributed to the movement along the Alicia Thrust Fault- a fault trending northeast-southwest. Noticeably, there was no surface rupture and the succeeding aftershocks clustered along a northeast-southwest trend off the eastern shore of Bohol island. In addition, the southeastern part of Bohol island experienced tsunami inundation particularly the municipalities of Jagna, Duero, Guindulman, Garcia Hernandez, and Valencia. In this study, several issues were resolved regarding this seismic event. First, the 1990 Bohol earthquake was generated along an offshore thrust fault based on the reviews of seismicity data from the NEIC. -Post-determined plots of the mainshock and aftershocks indicate offshore event with focal mechanism solutions that imply thrust fault activity. Intensity data likewise indicates that intense ground shaking was mainly felt in the southeastern part of the island. Second, recent field investigations undertaken clearly indicated a widespread tsunami inundation wherein the southeastern shorelines of Bohol likewise experienced a regional retreat in sea level several minutes after the strong ground shaking. Lastly, such tsunamigenic structure could somehow explain the anomalously large waves that impacted Camiguin island, an island more than 50km southeast of Bohol. A reconstruction of true tsunami heights and runup distances was also undertaken based from eyewitness accounts. Future works would involve relocation of aftershocks and numerical modeling of tsunami.

Trends that will affect your future … the coming food crisis-the social tsunami headed our way.

PubMed

Schwartz, Stephan A

2011-01-01

The Schwartzreport tracks emerging trends that will affect the world, particularly the United States. For EXPLORE it focuses on matters of health in the broadest sense of that term, including medical issues, changes in the biosphere, technology, and policy considerations, all of which will shape our culture and our lives. Copyright © 2011 Elsevier Inc. All rights reserved.

Development of a GNSS-Enhanced Tsunami Early Warning System

NASA Astrophysics Data System (ADS)

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?

Amplification of tsunami heights by delayed rupture of great earthquakes along the Nankai trough

NASA Astrophysics Data System (ADS)

Imai, K.; Satake, K.; Furumura, T.

2010-04-01

We investigated the effect of delayed rupture of great earthquakes along the Nankai trough on tsunami heights on the Japanese coast. As the tsunami source, we used a model of the 1707 Hoei earthquake, which consists of four segments: Tokai, Tonankai, and two Nankai segments. We first searched for the worst case, in terms of coastal tsunami heights, of rupture delay time on each segment, on the basis of superposition principle for the linear long wave theory. When the rupture starts on the Tonankai segment, followed by rupture on the Tokai segment 21 min later, as well as the eastern and western Nankai segments 15 and 28 min later, respectively, the average coastal tsunami height becomes the largest. To quantify the tsunami amplification, we compared the coastal tsunami heights from the delayed rupture with those from the simultaneous rupture model. Along the coasts of the sea of Hyu'uga and in the Bungo Channel, the tsunami heights become significantly amplified (>1.4 times larger) relative to the simultaneous rupture. Along the coasts of Tosa Bay and in the Kii Channel, the tsunami heights become amplified about 1.2 times. Along the coasts of the sea of Kumano and Ise Bay, and the western Enshu coast, the tsunami heights become slightly smaller for the delayed rupture. Along the eastern Enshu coast, the coast of Suruga Bay, and the west coast of Sagami Bay, the tsunami heights become amplified about 1.1 times.

Long-term statistics of extreme tsunami height at Crescent City

NASA Astrophysics Data System (ADS)

Dong, Sheng; Zhai, Jinjin; Tao, Shanshan

2017-06-01

Historically, Crescent City is one of the most vulnerable communities impacted by tsunamis along the west coast of the United States, largely attributed to its offshore geography. Trans-ocean tsunamis usually produce large wave runup at Crescent Harbor resulting in catastrophic damages, property loss and human death. How to determine the return values of tsunami height using relatively short-term observation data is of great significance to assess the tsunami hazards and improve engineering design along the coast of Crescent City. In the present study, the extreme tsunami heights observed along the coast of Crescent City from 1938 to 2015 are fitted using six different probabilistic distributions, namely, the Gumbel distribution, the Weibull distribution, the maximum entropy distribution, the lognormal distribution, the generalized extreme value distribution and the generalized Pareto distribution. The maximum likelihood method is applied to estimate the parameters of all above distributions. Both Kolmogorov-Smirnov test and root mean square error method are utilized for goodness-of-fit test and the better fitting distribution is selected. Assuming that the occurrence frequency of tsunami in each year follows the Poisson distribution, the Poisson compound extreme value distribution can be used to fit the annual maximum tsunami amplitude, and then the point and interval estimations of return tsunami heights are calculated for structural design. The results show that the Poisson compound extreme value distribution fits tsunami heights very well and is suitable to determine the return tsunami heights for coastal disaster prevention.

The Human Impact of Tsunamis: a Historical Review of Events 1900-2009 and Systematic Literature Review

PubMed Central

Doocy, Shannon; Daniels, Amy; Dick, Anna; Kirsch, Thomas D.

2013-01-01

Introduction. Although rare, tsunamis have the potential to cause considerable loss of life and injury as well as widespread damage to the natural and built environments. The objectives of this review were to describe the impact of tsunamis on human populations in terms of mortality, injury, and displacement and, to the extent possible, identify risk factors associated with these outcomes. This is one of five reviews on the human impact of natural disasters. Methods. Data on the impact of tsunamis were compiled using two methods, a historical review from 1900 to mid 2009 of tsunami events from multiple databases and a systematic literature review to October 2012 of publications. Analysis included descriptive statistics and bivariate tests for associations between tsunami mortality and characteristics using STATA 11. Findings. There were 255,195 deaths (range 252,619-275,784) and 48,462 injuries (range 45,466-51,457) as a result of tsunamis from 1900 to 2009. The majority of deaths (89%) and injuries reported during this time period were attributed to a single event –the 2004 Indian Ocean tsunami. Findings from the systematic literature review indicate that the primary cause of tsunami-related mortality is drowning, and that females, children and the elderly are at increased mortality risk. The few studies that reported on tsunami-related injury suggest that males and young adults are at increased injury-risk. Conclusions. Early warning systems may help mitigate tsunami-related loss of life. PMID:23857277

The human impact of tsunamis: a historical review of events 1900-2009 and systematic literature review.

PubMed

Doocy, Shannon; Daniels, Amy; Dick, Anna; Kirsch, Thomas D

2013-04-16

Introduction. Although rare, tsunamis have the potential to cause considerable loss of life and injury as well as widespread damage to the natural and built environments. The objectives of this review were to describe the impact of tsunamis on human populations in terms of mortality, injury, and displacement and, to the extent possible, identify risk factors associated with these outcomes. This is one of five reviews on the human impact of natural disasters. Methods. Data on the impact of tsunamis were compiled using two methods, a historical review from 1900 to mid 2009 of tsunami events from multiple databases and a systematic literature review to October 2012 of publications. Analysis included descriptive statistics and bivariate tests for associations between tsunami mortality and characteristics using STATA 11. Findings. There were 255,195 deaths (range 252,619-275,784) and 48,462 injuries (range 45,466-51,457) as a result of tsunamis from 1900 to 2009. The majority of deaths (89%) and injuries reported during this time period were attributed to a single event -the 2004 Indian Ocean tsunami. Findings from the systematic literature review indicate that the primary cause of tsunami-related mortality is drowning, and that females, children and the elderly are at increased mortality risk. The few studies that reported on tsunami-related injury suggest that males and young adults are at increased injury-risk. Conclusions. Early warning systems may help mitigate tsunami-related loss of life.

Power and Scour: Laboratory simulations of tsunami-induced scour

NASA Astrophysics Data System (ADS)

Todd, David; McGovern, David; Whitehouse, Richard; Harris, John; Rossetto, Tiziana

2017-04-01

The world's coastal regions are becoming increasingly urbanised and densely populated. Recent major tsunami events in regions such as Samoa (2007), Indonesia (2004, 2006, 2010), and Japan (2011) have starkly highlighted this effect, resulting in catastrophic loss of both life and property, with much of the damage to buildings being reported in EEFIT mission reports following each of these events. The URBANWAVES project, led by UCL in collaboration with HR Wallingford, brings the power of the tsunami to the laboratory for the first time. The Pneumatic Tsunami Simulator is capable of tsimulating both idealised and real-world tsunami traces at a scale of 1:50. Experiments undertaken in the Fast Flow Facility at HR Wallingford using square and rectangular buildings placed on a sediment bed have allow us to measure, for the first time under laboratory conditions, the variations in the flow field around buildings produced by tsunami waves as a result of the scour process. The results of these tests are presented, providing insight into the process of scour development under different types of tsunami, giving a glimpse into the power of tsunamis that have already occurred, and helping us to inform the designs of future buildings so that we can be better prepared to analyse and design against these failure modes in the future. Additional supporting abstracts include Foster et al., on tsunami induced building loads; Chandler et al., on the tsunami simulation concept and McGovern et al., on the simulation of tsunami-driven scour and flow fields.

Marin Tsunami (video)

USGS Publications Warehouse

Filmed and edited by: Loeffler, Kurt; Gesell, Justine

2010-01-01

Tsunamis are a constant threat to the coasts of our world. Although tsunamis are infrequent along the West coast of the United States, it is possible and necessary to prepare for potential tsunami hazards to minimize loss of life and property. Community awareness programs are important, as they strive to create an informed society by providing education and training. The Marin coast could be struck by a tsunami. Whether you live in Marin County, visit the beaches, or rent or own a home near the coast, it is vital to understand the tsunami threat and take preparation seriously. Marin Tsunami tells the story of what several West Marin communities are doing to be prepared. This video was produced by the US Geological Survey (USGS) in cooperation with the Marin Office of Emergency Services.

Duration of Tsunami Generation Longer than Duration of Seismic Wave Generation in the 2011 Mw 9.0 Tohoku-Oki Earthquake

NASA Astrophysics Data System (ADS)

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., 2011; Ide at al., 2011; Yagi and Fukahata, 2011; Suzuki et al., 2011). The comparison of two type of moment rate functions, inferred from finite source imaging of tsunami waveforms and seismic waveforms, suggested that there was the time period common to both seismic wave generation and tsunami generation followed by the time period unique to tsunami generation. At this point, we think that comparison of the absolute values of moment rates is not so meaningful between tsunami waveform inversion and seismic waveform inversion, because of general ambiguity of rigidity values of each subfault in the fault region (assuming the rigidity value of 30 GPa of Yoshida et al (2011)). Considering this, the normalized value of moment rate function was also evaluated and it does not change the general feature of two moment rate functions in terms of duration property. Furthermore, the results suggested that tsunami generation process apparently took more time than seismic wave generation process did. Tsunami can be generated even by "extra" motions resulting from many suggested abnormal mechanisms. These extra motions may be attribute to the relatively larger-scale tsunami generation than expected from the magnitude level from seismic ground motion, and attribute to the longer duration of tsunami generation process.

Sedimentary Record and Morphological Effects of a Landslide-Generated Tsunami in a Polar Region: The 2000 AD Tsunami in Vaigat Strait, West Greenland

NASA Astrophysics Data System (ADS)

Szczucinski, W.; Rosser, N. J.; Strzelecki, M. C.; Long, A. J.; Lawrence, T.; Buchwal, A.; Chague-Goff, C.; Woodroffe, S.

2012-12-01

To date, the effects of tsunami erosion and deposition have mainly been reported from tropical and temperate climatic zones yet tsunamis are also frequent in polar zones, particularly in fjord settings where they can be generated by landslides. Here we report the geological effects of a landslide-triggered tsunami that occurred on 21st November 2000 in Vaigat, northern Disko Bugt in west Greenland. To characterise the typical features of this tsunami we completed twelve detailed coastal transects in a range of depositional settings: cliff coasts, narrow to moderate width coastal plains, lagoons and a coastal lake. At each setting we completed a detailed map using a laser scanner and DGPS survey. The tsunami deposits were described from closely spaced trenches and, from the lake, by a series of sediment cores . At each setting we examined the sedimentological properties of the deposits, as well as their bulk geochemistry and diatom content. Selected specimens of arctic willow from inundated and non-inundated areas were collected to assess the impact of the event in their growth ring records. Samples of sediments beneath the AD 2000 deposit were studied for 137Cs to confirm the age of the tsunami and to assess the extent of erosion. Offshore sediment samples, modern beach and soils/sediments underlying the AD 2000 tsunami deposits were sampled to determine tsunami deposit sources. The observed tsunami run-up exceeded 20 m next to the tsunami trigger - a rock avalanche at Paatuut - and up to 10 m on the opposite coast of the fjord. The inland inundation distance ranged from several tens of meters to over 300 m. The wave was recorded as far as 180 km away from the source. The tsunami inundated the coast obliquely to the shoreline in all locations studied. The tsunami frequently caused erosion of existing beach ridges whilst erosional niches were formed inland. The tsunami deposits mainly comprise gravels and very coarse sand. They are over 30 cm thick close to the coast and in front of inland scarps. In the most inland parts of the inundation they are often marked only by patches of coarse sand left on the pre-tsunami soil. At several sites we observed boulder deposits, although in many cases they were likely transported as boulders in icebergs. A characteristic feature related to tsunami deposits were "mud pats" - up to 1 m in diameter and about 20 cm thick silty deposits with occasional gravels - which cover the tsunami deposit. They are interpreted as the result of melting of icebergs washed inland by the tsunami. They often occur close to the inundation limit. The mud pats are a characteristic feature for the tsunami deposits in iceberg dominated settings and are unlikely to be left by storms. The results of this study will serve as a guide for further studies of palaeotsunami in the Vaigat region and elsewhere in polar regions. The study was funded by Polish National Science Centre grant No. 2011/01/B/ST10/01553. Fieldwork was supported by the Arctic Station, Disko (Danish Polar Centre). The police at Ilulissat is acknowledged for providing photographic documentation of the tsunami taken one day after the event.

Tsunamis of the northeast Indian Ocean with a particular focus on the Bay of Bengal region—A synthesis and review

NASA Astrophysics Data System (ADS)

Alam, Edris; Dominey-Howes, Dale; Chagué-Goff, Catherine; Goff, James

2012-08-01

The 2004 Indian Ocean Tsunami (2004 IOT) challenged assumptions about the level of regional hazard. Significantly, there has been some debate about the hypothesis that the northern Bay of Bengal may be capable of generating large tsunamis similar to the 2004 IOT. To test this hypothesis, we documented historical and palaeotsunamis in the northeast Indian Ocean. Using multiple sources, we identified 135 purported tsunamis. After completing a process of validity assessment, we categorised 31 definite tsunamis, 27 probable tsunamis, 51 doubtful tsunamis and 20 events that only caused a seiche or disturbance in an inland river. Six of the purported events were identified as either cyclones or earthquakes without any associated tsunamis. Using the reported list of 135 events, we identified different tsunamigenic regions and explored the temporal distribution of past events, with the oldest event dated to around 38,000BC (although the dated material is most likely reworked and this was probably a Holocene event). The second oldest event dated to 3000-2000BC. Historical records indicate that only one definite tsunami, occurring in AD1762, was generated in the northern Bay of Bengal. We encountered a number of significant challenges in reviewing and analysing data contained within the documents and sources we consulted. Statistical analysis of tsunami data from AD1710 to AD2010 suggests that the occurrence of a tsunami affecting the coasts of Bangladesh and Myanmar is 0.99% in any given year, and 63% in a century. We recognise that this incomplete tsunami dataset limits the capacity to fully quantify the hazard. As such, we recommend further 'deep' archival research coupled with regional palaeotsunami studies to gain a more sophisticated understanding of the hazard.

Fault Slip Distribution of the 2016 Fukushima Earthquake Estimated from Tsunami Waveforms

NASA Astrophysics Data System (ADS)

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.

Observing Traveling Ionospheric Disturbances Caused by Tsunamis Using GPS TEC Measurements

NASA Technical Reports Server (NTRS)

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.

Tsunami deposits associated with the 7.3 ka caldera-forming eruption of the Kikai Caldera, insights for tsunami generation during submarine caldera-forming eruptions

NASA Astrophysics Data System (ADS)

Geshi, Nobuo; Maeno, Fukashi; Nakagawa, Shojiro; Naruo, Hideto; Kobayashi, Tetsuo

2017-11-01

Timing and mechanism of volcanic tsunamis will be a key to understand the dynamics of large-scale submarine explosive volcanism. Tsunami deposits associated with the VEI 7 eruption of the Kikai Caldera at 7.3 ka are found in the Yakushima and Kuchinoerabujima Islands, 40 km south -southeast of the caldera rim. The tsunami deposits distribute along the rivers in their northern coast up to 4.5 km from the river exit and up to 50 m above the present sea level. The tsunami deposits in the Yakushima area consist of pumice-bearing gravels in the lower part of the section (Unit I) and pumiceous conglomerate in the upper part (Unit II). The presence of rounded pebbles of sedimentary rocks, which characterize the beach deposit, indicates a run-up current from the coastal area. The rip-up clasts of the underlying paleosol in Unit I show strong erosion during the invasion of tsunami. Compositional similarity between the pumices in the tsunami deposit and the juvenile materials erupted in the early phase of the Akahoya eruption indicates the formation of tsunami deposit during the early phase of the eruption, which produced the initial Plinian pumice fall and the lower half of the Koya pyroclastic flow. Presence of the dense volcanic components (obsidians and lava fragments) besides pumices in the tsunami deposit supports that they were carried by the Koya pyroclastic flow, and not the pumices floating on the sea surface. Sequential relationship between the Koya pyroclastic flow and the tsunami suggests that the emplacement of the pyroclastic flow into the sea surrounding the caldera is the most probable mechanism of the tsunami.

Source parameters controlling the generation and propagation of potential local tsunamis along the cascadia margin

USGS Publications Warehouse

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.

Signals in the ionosphere generated by tsunami earthquakes: observations and modeling suppor

NASA Astrophysics Data System (ADS)

Rolland, L.; Sladen, A.; Mikesell, D.; Larmat, C. S.; Rakoto, V.; Remillieux, M.; Lee, R.; Khelfi, K.; Lognonne, P. H.; Astafyeva, E.

2017-12-01

Forecasting systems failed to predict the magnitude of the 2011 great tsunami in Japan due to the difficulty and cost of instrumenting the ocean with high-quality and dense networks. Melgar et al. (2013) show that using all of the conventional data (inland seismic, geodetic, and tsunami gauges) with the best inversion method still fails to predict the correct height of the tsunami before it breaks onto a coast near the epicenter (< 500 km). On the other hand, in the last decade, scientists have gathered convincing evidence of transient signals in the ionosphere Total Electron Content (TEC) observations that are associated to open ocean tsunami waves. Even though typical tsunami waves are only a few centimeters high, they are powerful enough to create atmospheric vibrations extending all the way to the ionosphere, 300 kilometers up in the atmosphere. Therefore, we are proposing to incorporate the ionospheric signals into tsunami early-warning systems. We anticipate that the method could be decisive for mitigating "tsunami earthquakes" which trigger tsunamis larger than expected from their short-period magnitude. These events are challenging to characterize as they rupture the near-trench subduction interface, in a distant region less constrained by onshore data. As a couple of devastating tsunami earthquakes happens per decade, they represent a real threat for onshore populations and a challenge for tsunami early-warning systems. We will present the TEC observations of the recent Java 2006 and Mentawaii 2010 tsunami earthquakes and base our analysis on acoustic ray tracing, normal modes summation and the simulation code SPECFEM, which solves the wave equation in coupled acoustic (ocean, atmosphere) and elastic (solid earth) domains. Rupture histories are entered as finite source models, which will allow us to evaluate the effect of a relatively slow rupture on the surrounding ocean and atmosphere.

Making Multi-Level Tsunami Evacuation Playbooks Operational in California and Hawaii

NASA Astrophysics Data System (ADS)

Wilson, R. I.; Peterson, D.; Fryer, G. J.; Miller, K.; Nicolini, T.; Popham, C.; Richards, K.; Whitmore, P.; Wood, N. J.

2016-12-01

In the aftermath of the 2010 Chile, 2011 Japan, and 2012 Haida Gwaii tsunamis in California and Hawaii, coastal emergency managers requested that state and federal tsunami programs investigate providing more detailed information about the flood potential and recommended evacuation for distant-source tsunamis well ahead of their arrival time. Evacuation "Playbooks" for tsunamis of variable sizes and source locations have been developed for some communities in the two states, providing secondary options to an all or nothing approach for evacuation. Playbooks have been finalized for nearly 70% of the coastal communities in California, and have been drafted for evaluation by the communities of Honolulu and Hilo in Hawaii. A key component to determining a recommended level of evacuation during a distant-source tsunami and making the Playbooks operational has been the development of the "FASTER" approach, an acronym for factors that influence the tsunami flood hazard for a community: Forecast Amplitude, Storm, Tides, Error in forecast, and the Run-up potential. Within the first couple hours after a tsunami is generated, the FASTER flood elevation value will be computed and used to select the appropriate minimum tsunami phase evacuation "Playbook" for use by the coastal communities. The states of California and Hawaii, the tsunami warning centers, and local weather service offices are working together to deliver recommendations on the appropriate evacuation Playbook plans for communities to use prior to the arrival of a distant-source tsunami. These partners are working closely with individual communities on developing conservative and consistent protocols on the use of the Playbooks. Playbooks help provide a scientifically-based, minimum response for small- to moderate-size tsunamis which could reduce the potential for over-evacuation of hundreds of thousands of people and save hundreds of millions of dollars in evacuation costs for communities and businesses.

A probabilistic tsunami hazard assessment for Indonesia

NASA Astrophysics Data System (ADS)

Horspool, N.; Pranantyo, I.; Griffin, J.; Latief, H.; Natawidjaja, D. H.; Kongko, W.; Cipta, A.; Bustaman, B.; Anugrah, S. D.; Thio, H. K.

2014-11-01

Probabilistic hazard assessments are a fundamental tool for assessing the threats posed by hazards to communities and are important for underpinning evidence-based decision-making regarding risk mitigation activities. Indonesia has been the focus of intense tsunami risk mitigation efforts following the 2004 Indian Ocean tsunami, but this has been largely concentrated on the Sunda Arc with little attention to other tsunami prone areas of the country such as eastern Indonesia. We present the first nationally consistent probabilistic tsunami hazard assessment (PTHA) for Indonesia. This assessment produces time-independent forecasts of tsunami hazards at the coast using data from tsunami generated by local, regional and distant earthquake sources. The methodology is based on the established monte carlo approach to probabilistic seismic hazard assessment (PSHA) and has been adapted to tsunami. We account for sources of epistemic and aleatory uncertainty in the analysis through the use of logic trees and sampling probability density functions. For short return periods (100 years) the highest tsunami hazard is the west coast of Sumatra, south coast of Java and the north coast of Papua. For longer return periods (500-2500 years), the tsunami hazard is highest along the Sunda Arc, reflecting the larger maximum magnitudes. The annual probability of experiencing a tsunami with a height of > 0.5 m at the coast is greater than 10% for Sumatra, Java, the Sunda islands (Bali, Lombok, Flores, Sumba) and north Papua. The annual probability of experiencing a tsunami with a height of > 3.0 m, which would cause significant inundation and fatalities, is 1-10% in Sumatra, Java, Bali, Lombok and north Papua, and 0.1-1% for north Sulawesi, Seram and Flores. The results of this national-scale hazard assessment provide evidence for disaster managers to prioritise regions for risk mitigation activities and/or more detailed hazard or risk assessment.

USGS scientists study sediment deposited by 2004 Indian Ocean tsunami

USGS Publications Warehouse

2005-01-01

In January, U.S. Geological Survey (USGS) scientists traveled to countries on the Indian Ocean to study sediment deposited by the devastating tsunami of December 26, 2004. They hope to gain knowledge that will help them to identify ancient tsunami deposits in the geologic record—which extends much farther into the past than written records—and so compile a history of tsunamis that can be used to assess a region's future tsunami risk.

Impact of tsunami on texture and mineralogy of a major placer deposit in southwest coast of India

NASA Astrophysics Data System (ADS)

Babu, N.; Babu, D. S. Suresh; Das, P. N. Mohan

2007-03-01

The great Indonesian earth quake (26 December 2004) triggered a tsunami wave across the Bay of Bengal and Indian Ocean basins and has brought a major havoc in several countries including India. The coastal segment between Thotapalli and Valiazhikal in Kerala state of southwest India, where considerably rich beach placer deposit with ilmenite percentage of more than 70% is concentrated, has been investigated to understand the impact of tsunami on coastal sediments. The grain size analysis flashes out the significant differences between the pre- and post-tsunami littoral environments. While the mineral grains collected during pre-tsunami period show well-sorted nature, the post-tsunami samples represent moderately to poorly sorted nature. Similarly, unimodal and bimodal distributions of the sediments have been recorded for pre- and post-tsunami sediments, respectively. Further, mineral assemblages corresponding to before and after this major wave activity clearly indicate the large-scale redistribution of sediments. The post-tsunami sediments register increasing trends of garnet, sillimanite and rutile. The total heavy mineral percentage of the post-tsunami sediment also shows an improved concentration, perhaps due to the large-scale transport of lighter fraction. Magnetite percentage of post-tsunami samples reflects higher concentration compared to the pre-tsunami samples, indicating the intensity of reworking process. X-ray diffraction patterns of ilmenite grains have confirmed the increased presence of pseduorutile, and pseudobrookite in post-tsunami samples, which could be due to the mixing of more altered grains. SEM examination of grains also confirms the significant alteration patterns on the ubiquitous mineral of placer body, the ilmenite. The reason for these textural, mineralogical and micromorphological changes in heavy minerals particularly in ilmenite, could be due to the churning action on the deeper sediments of onshore region or on the sediments entrapped in the near shelf region of the area, by the ˜ 6 m high tsunami waves.

Proposal of a method for evaluating tsunami risk using response-surface methodology

NASA Astrophysics Data System (ADS)

Fukutani, Y.

2017-12-01

Information on probabilistic tsunami inundation hazards is needed to define and evaluate tsunami risk. Several methods for calculating these hazards have been proposed (e.g. Løvholt et al. (2012), Thio (2012), Fukutani et al. (2014), Goda et al. (2015)). However, these methods are inefficient, and their calculation cost is high, since they require multiple tsunami numerical simulations, therefore lacking versatility. In this study, we proposed a simpler method for tsunami risk evaluation using response-surface methodology. Kotani et al. (2016) proposed an evaluation method for the probabilistic distribution of tsunami wave-height using a response-surface methodology. We expanded their study and developed a probabilistic distribution of tsunami inundation depth. We set the depth (x1) and the slip (x2) of an earthquake fault as explanatory variables and tsunami inundation depth (y) as an object variable. Subsequently, tsunami risk could be evaluated by conducting a Monte Carlo simulation, assuming that the generation probability of an earthquake follows a Poisson distribution, the probability distribution of tsunami inundation depth follows the distribution derived from a response-surface, and the damage probability of a target follows a log normal distribution. We applied the proposed method to a wood building located on the coast of Tokyo Bay. We implemented a regression analysis based on the results of 25 tsunami numerical calculations and developed a response-surface, which was defined as y=ax1+bx2+c (a:0.2615, b:3.1763, c=-1.1802). We assumed proper probabilistic distribution for earthquake generation, inundation height, and vulnerability. Based on these probabilistic distributions, we conducted Monte Carlo simulations of 1,000,000 years. We clarified that the expected damage probability of the studied wood building is 22.5%, assuming that an earthquake occurs. The proposed method is therefore a useful and simple way to evaluate tsunami risk using a response-surface and Monte Carlo simulation without conducting multiple tsunami numerical simulations.

Advanced Tsunami Numerical Simulations and Energy Considerations by use of 3D-2D Coupled Models: The October 11, 1918, Mona Passage Tsunami

NASA Astrophysics Data System (ADS)

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.

Geological Evidences for a Large Tsunami Generated by the 7.3 ka Kikai Caldera Eruption, Southern Japan

NASA Astrophysics Data System (ADS)

Yamada, M.; Fujino, S.; Satake, K.

2017-12-01

The 7.3 ka eruption of Kikai volcano, southern Kyushu, Japan, is one of the largest caldera-forming eruption in the world. Given that a huge caldera was formed in shallow sea area during the eruption, a tsunami must have been generated by a sea-level change associated. Pyroclastic flow and tsunami deposits by the eruption have been studied around the caldera, but they are not enough to evaluate the tsunami size. The goal of this study is to unravel sizes of tsunami and triggering caldera collapse by numerical simulations based on a widely-distributed tsunami deposit associated with the eruption. In this presentation, we will provide an initial data on distribution of the 7.3 ka tsunami deposit contained in sediment cores taken at three coastal lowlands in Wakayama, Tokushima, and Oita prefectures (560 km, 520 km, and 310 km north-east from the caldera, respectively). A volcanic ash from the eruption (Kikai Akahoya tephra: K-Ah) is evident in organic-rich muddy sedimentary sequence in all sediment cores. Up to 6-cm-thick sand layer, characterized by a grading structure and sharp bed boundary with lower mud, is observed immediately beneath the K-Ah tephra in all study sites. These sedimentary characteristics and broad distribution indicate that the sand layer was most likely deposited by a tsunami which can propagate to a wide area, but not by a local storm surge. Furthermore, the stratigraphic relationship implies that the study sites must have been inundated by the tsunami prior to the ash fall. A sand layer is also evident within the K-Ah tephra layer, suggesting that the sand layer was probably formed by a subsequent tsunami wave during the ash fall. These geological evidences for the 7.3 ka tsunami inundation will contribute to a better understanding of the caldera collapse and the resultant tsunami, but also of the tsunami generating system in the eruptive process.

Modeling Extra-Long Tsunami Propagation: Assessing Data, Model Accuracy and Forecast Implications

NASA Astrophysics Data System (ADS)

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.

Numerical Simulations of the 1991 Limón Tsunami, Costa Rica Caribbean Coast

NASA Astrophysics Data System (ADS)

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.

Effects of the Great East Japan Earthquake and huge tsunami on glycaemic control and blood pressure in patients with diabetes mellitus

PubMed Central

Ishiki, Mikihito; Nako, Kazuhiro; Okamura, Masashi; Senda, Miho; Sakamoto, Takuya; Ito, Sadayoshi

2012-01-01

Objective To examine the effects of a huge tsunami resulting from the Great East Japan Earthquake on blood pressure (BP) control and glycaemic control in diabetic patients. Design A retrospective study. Setting Tohoku University, Japan. Participants 63 patients were visiting Rikuzentakata Hospital for diabetic treatment before the earthquake and returned to the clinic in July after the earthquake, and they were analysed in the present study. The subjects were divided into two groups: those who were hit by the tsunami, the Tsunami (+) group (n=28), and those who were not, the Tsunami (−) group (n=35), and the groups' parameters and their changes were compared. Primary outcome measure Changes of HbA1c. Secondary outcome measures Changes of BP, body mass index. Results HbA1c and both BP increased, while the numbers of most drugs taken decreased in both groups. Parameter changes were significantly greater in the Tsunami (+) group. All medical data stored at the hospital was lost in the tsunami. The Tsunami (+) patients also had their own records of treatment washed away, so it was difficult to replicate their pre-earthquake drug prescriptions afterwards. In comparison, the Tsunami (−) patients kept their treatment information, making it possible to resume the treatment they had been receiving before the earthquake. The BP rose only slightly in men, whereas it rose sharply in women, even though they had not been directly affected by the tsunami. BP rose markedly in both genders affected by the tsunami. Conclusions All medical information was lost in the tsunami, and glycaemic and BP controls of the tsunami-affected patients worsened more than those of patients who had been affected by the earthquake alone. Women may be more sensitive to changes in the living environment that result from a major earthquake than are men. PMID:22505311

International year of planet earth 7. Oceans, submarine land-slides and consequent tsunamis in Canada

USGS Publications Warehouse

Mosher, D.C.

2009-01-01

Canada has the longest coastline and largest continental margin of any nation in the World. As a result, it is more likely than other nations to experience marine geohazards such as submarine landslides and consequent tsunamis. Coastal landslides represent a specific threat because of their possible proximity to societal infrastructure and high tsunami potential; they occur without warning and with little time lag between failure and tsunami impact. Continental margin landslides are common in the geologic record but rare on human timescales. Some ancient submarine landslides are massive but more recent events indicate that even relatively small slides on continental margins can generate devastating tsunamis. Tsunami impact can occur hundreds of km away from the source event, and with less than 2 hours warning. Identification of high-potential submarine landslide regions, combined with an understanding of landslide and tsunami processes and sophisticated tsunami propagation models, are required to identify areas at high risk of impact.

Tsunami Hazard Assessment of Coastal South Africa Based on Mega-Earthquakes of Remote Subduction Zones

NASA Astrophysics Data System (ADS)

Kijko, Andrzej; Smit, Ansie; Papadopoulos, Gerassimos A.; Novikova, Tatyana

2018-04-01

After the mega-earthquakes and concomitant devastating tsunamis in Sumatra (2004) and Japan (2011), we launched an investigation into the potential risk of tsunami hazard to the coastal cities of South Africa. This paper presents the analysis of the seismic hazard of seismogenic sources that could potentially generate tsunamis, as well as the analysis of the tsunami hazard to coastal areas of South Africa. The subduction zones of Makran, South Sandwich Island, Sumatra, and the Andaman Islands were identified as possible sources of mega-earthquakes and tsunamis that could affect the African coast. Numerical tsunami simulations were used to investigate the realistic and worst-case scenarios that could be generated by these subduction zones. The simulated tsunami amplitudes and run-up heights calculated for the coastal cities of Cape Town, Durban, and Port Elizabeth are relatively small and therefore pose no real risk to the South African coast. However, only distant tsunamigenic sources were considered and the results should therefore be viewed as preliminary.

Errors in Tsunami Source Estimation from Tide Gauges

NASA Astrophysics Data System (ADS)

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.

Tsunami Hazard Assessment of Coastal South Africa Based on Mega-Earthquakes of Remote Subduction Zones

NASA Astrophysics Data System (ADS)

Kijko, Andrzej; Smit, Ansie; Papadopoulos, Gerassimos A.; Novikova, Tatyana

2017-11-01

After the mega-earthquakes and concomitant devastating tsunamis in Sumatra (2004) and Japan (2011), we launched an investigation into the potential risk of tsunami hazard to the coastal cities of South Africa. This paper presents the analysis of the seismic hazard of seismogenic sources that could potentially generate tsunamis, as well as the analysis of the tsunami hazard to coastal areas of South Africa. The subduction zones of Makran, South Sandwich Island, Sumatra, and the Andaman Islands were identified as possible sources of mega-earthquakes and tsunamis that could affect the African coast. Numerical tsunami simulations were used to investigate the realistic and worst-case scenarios that could be generated by these subduction zones. The simulated tsunami amplitudes and run-up heights calculated for the coastal cities of Cape Town, Durban, and Port Elizabeth are relatively small and therefore pose no real risk to the South African coast. However, only distant tsunamigenic sources were considered and the results should therefore be viewed as preliminary.

Geologic impacts of the 2004 Indian ocean tsunami on Indonesia, Sri Lanka, and the Maldives

USGS Publications Warehouse

Richmond, B.M.; Jaffe, B.E.; Gelfenbaum, G.; Morton, R.A.

2006-01-01

The December 26, 2004 Indian Ocean tsunami was generated by a large submarine earthquake (magnitude ???9.1) with an epicenter located under the seafloor in the eastern Indian Ocean near northern Sumatra, Indonesia. The resulting tsunami was measured globally and had significant geologic impacts throughout the Indian Ocean basin. Observations of tsunami impacts, such as morphologic change, sedimentary deposits, and water-level measurements, are used to reconstruct tsunamogenic processes. Data from Sumatra, Sri Lanka, and the Maldives provide a synoptic view of tsunami characteristics from a wide range of coastal environments both near- and far-field from the tsunami origin. Impacts to the coast as a result of the tsunami varied depending upon the height of the wave at impact, orientation of the coast with regard to direction of wave approach, and local topography, bathymetry, geology, and vegetation cover. Tsunami deposits were observed in all the countries visited and can be generally characterized as relatively thin sheets (<80 cm), mostly of sand. ?? 2006 Gebru??der Borntraeger.

The living environment and children's fears following the Indonesian tsunami

PubMed Central

Du, Ye Beverly; Lee, Christopher Thomas; Christina, Desy; Belfer, Myron L.; Betancourt, Theresa S.; O'Rourke, Edward James; Palfrey, Judith S.

2014-01-01

The tsunami that struck South-east Asia on 26 December 2004 left more than 500,000 people in Aceh, Indonesia, homeless and displaced to temporary barracks and other communities. This study examines the associations between prolonged habitation in barracks and the nature of fears reported by school-age children and adolescents. In mid-2007, 30 months after the tsunami, the authors interviewed 155 child and parent dyads. Logistic regression analysis was used to compare the fears reported by children and adolescents living in barracks with those reported by their peers who were living in villages. After adjusting for demographic factors and tsunami exposure, the data reveals that children and adolescents living in barracks were three times more likely than those living in villages to report tsunami-related fears. The study demonstrates that continued residence in barracks 30 months after the tsunami is associated with higher rates of reporting tsunami-related fears, suggesting that barracks habitation has had a significant impact on the psychological experience of children and adolescents since the tsunami. PMID:22098206

A Tsunami-Focused Tide Station Data Sharing Framework

NASA Astrophysics Data System (ADS)

Kari, U. S.; Marra, J. J.; Weinstein, S. A.

2006-12-01

The Indian Ocean Tsunami of 26 December 2004 made it clear that information about tide stations that could be used to support detection and warning (such as location, collection and transmission capabilities, operator identification) are insufficiently known or not readily accessible. Parties interested in addressing this problem united under the Pacific Region Data Integrated Data Enterprise (PRIDE), and in 2005 began a multiyear effort to develop a distributed metadata system describing tide stations starting with pilot activities in a regional framework and focusing on tsunami detection and warning systems being developed by various agencies. First, a plain semantic description of the tsunami-focused tide station metadata was developed. The semantic metadata description was, in turn, developed into a formal metadata schema championed by International Tsunami Information Centre (ITIC) as part of a larger effort to develop a prototype web service under the PRIDE program in 2005. Under the 2006 PRIDE program the formal metadata schema was then expanded to corral input parameters for the TideTool application used by Pacific Tsunami Warning Center (PTWC) to drill down into wave activity at a tide station that is located using a web service developed on this metadata schema. This effort contributed to formalization of web service dissemination of PTWC watch and warning tsunami bulletins. During this time, the data content and sharing issues embodied in this schema have been discussed at various forums. The result is that the various stakeholders have different data provider and user perspectives (semantic content) and also exchange formats (not limited to just XML). The challenge then, is not only to capture all data requirements, but also to have formal representation that is easily transformed into any specified format. The latest revision of the tide gauge schema (Version 0.3), begins to address this challenge. It encompasses a broader range of provider and user perspectives, such as station operators, warning system managers, disaster managers, other marine hazard warning systems (such as storm surges and sea level change monitoring and research. In the next revision(s), we hope to take into account various relevant standards, including specifically, the Open Geospatial Consortium (OGC) Sensor Web Enablement (SWE) Framework, that will serve all prospective stakeholders in the most useful (extensible, scalable) manner. This is because Sensor ML has addressed many of the challenges we face already, through very useful fundamental modeling consideration and data types that are particular to sensors in general, with perhaps some extension needed for tide gauges. As a result of developing this schema, and associated client application architectures, we hope to have a much more distributed network of data providers, who are able to contribute to a global tide station metadata from the comfort of their own Information Technology (IT) departments.

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

NASA Astrophysics Data System (ADS)

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, the final estimated location of LSZ and SLSZ in BZ are estimated well.

Effects of fringing reefs on tsunami inundation: American Samoa

USGS Publications Warehouse

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 cause a significant increase in tsunami wave heights, inundation distances, and velocities. Wide embayments, similar in size to Massacre Bay, induce some tsunami amplification, but not as much as for the narrowing embayment.

Real-time tsunami inundation forecasting and damage mapping towards enhancing tsunami disaster resiliency

NASA Astrophysics Data System (ADS)

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 responders and stakeholders, e.g. national and regional municipalities, to be utilized for their emergency/response activities. In 2014, the system is verified through the case studies of 2011 Tohoku event and potential earthquake scenarios along Nankai Trough with regard to its capability and robustness.

New approaches in geological studies of tsunami deposits

NASA Astrophysics Data System (ADS)

Szczucinski, Witold

2017-04-01

During the last dozen of years tsunamis have appeared to be the most disastrous natural process worldwide. The dramatic, large tsunamis on Boxing Day, 2004 in the Indian Ocean and on March 11, 2011 offshore Japan caused catastrophes listed as the worst in terms of the number of victims and the economic losses, respectively. In the aftermath, they have become a topic of high public and scientific interest. The record of past tsunamis, mainly in form of tsunami deposits, is often the only way to identify tsunami risk at a particular coast due to relatively low frequency of their occurrence. The identification of paleotsunami deposits is often difficult mainly because the tsunami deposits are represented by various sediment types, may be similar to storm deposits or altered by post-depositional processes. There is no simple universal diagnostic set of criteria that can be applied to interpret tsunami deposits with certainty. Thus, there is a need to develop new methods, which would enhance 'classical', mainly sedimentological and stratigraphic approach. The objective of the present contribution is to show recent progress and application of new approaches including geochemistry (Chagué-Goff et al. 2017) and paleogenetics (Szczuciński et al. 2016) in studies of geological impacts of recent tsunamis from various geographical regions, namely in monsoonal-tropical, temperate and polar zones. It is mainly based on own studies of coastal zones affected by 2004 Indian Ocean Tsunami in Thailand, 2011 Tohoku-oki tsunami and older paleotsunamis in Japan, catastrophic saltwater inundations at the coasts of Baltic Sea and 2000 landslide-generated tsunami in Vaigat Strait (west Greenland). The study was partly funded by Polish National Science Centre grant No. 2011/01/B/ST10/01553. Chagué-Goff C., Szczuciński W., Shinozaki T., 2017. Applications of geochemistry in tsunami research: A review. Earth-Science Reviews 165: 203-244. Szczuciński W., Pawłowska J., Lejzerowicz F., Nishimura Y., Kokociński M., Majewski W., Nakamura Y., Pawlowski J., 2016. Ancient sedimentary DNA reveals past tsunami deposits. Marine Geology 381: 29-33.

Assessment of tsunami hazard for coastal areas of Shandong Province, China

NASA Astrophysics Data System (ADS)

Feng, Xingru; Yin, Baoshu

2017-04-01

Shandong province is located on the east coast of China and has a coastline of about 3100 km. There are only a few tsunami events recorded in the history of Shandong Province, but the tsunami hazard assessment is still necessary as the rapid economic development and increasing population of this area. The objective of this study was to evaluate the potential danger posed by tsunamis for Shandong Province. The numerical simulation method was adopted to assess the tsunami hazard for coastal areas of Shandong Province. The Cornell multi-grid coupled tsunami numerical model (COMCOT) was used and its efficacy was verified by comparison with three historical tsunami events. The simulated maximum tsunami wave height agreed well with the observational data. Based on previous studies and statistical analyses, multiple earthquake scenarios in eight seismic zones were designed, the magnitudes of which were set as the potential maximum values. Then, the tsunamis they induced were simulated using the COMCOT model to investigate their impact on the coastal areas of Shandong Province. The numerical results showed that the maximum tsunami wave height, which was caused by the earthquake scenario located in the sea area of the Mariana Islands, could reach up to 1.39 m off the eastern coast of Weihai city. The tsunamis from the seismic zones of the Bohai Sea, Okinawa Trough, and Manila Trench could also reach heights of >1 m in some areas, meaning that earthquakes in these zones should not be ignored. The inundation hazard was distributed primarily in some northern coastal areas near Yantai and southeastern coastal areas of Shandong Peninsula. When considering both the magnitude and arrival time of tsunamis, it is suggested that greater attention be paid to earthquakes that occur in the Bohai Sea. In conclusion, the tsunami hazard facing the coastal area of Shandong Province is not very serious; however, disasters could occur if such events coincided with spring tides or other extreme oceanic conditions. The results of this study will be useful for the design of coastal engineering projects and the establishment of a tsunami warning system for Shandong Province.

Sources of information for tsunami forecasting in New Zealand

NASA Astrophysics Data System (ADS)

Barberopoulou, A.; Ristau, J. P.; D'Anastasio, E.; Wang, X.

2013-12-01

Tsunami science has evolved considerably in the last two decades due to technological advancements which also helped push for better numerical modelling of the tsunami phases (generation to inundation). The deployment of DART buoys has also been a considerable milestone in tsunami forecasting. Tsunami forecasting is one of the parts that tsunami modelling feeds into and is related to response, preparedness and planning. Usually tsunami forecasting refers to short-term forecasting that takes place in real-time after a tsunami has or appears to have been generated. In this report we refer to all types of forecasting (short-term or long-term) related to work in advance of a tsunami impacting a coastline that would help in response, planning or preparedness. We look at the standard types of data (seismic, GPS, water level) that are available in New Zealand for tsunami forecasting, how they are currently being used, other ways to use these data and provide recommendations for better utilisation. The main findings are: -Current investigations of the use of seismic parameters quickly obtained after an earthquake, have potential to provide critical information about the tsunamigenic potential of earthquakes. Further analysis of the most promising methods should be undertaken to determine a path to full implementation. -Network communication of the largest part of the GPS network is not currently at a stage that can provide sufficient data early enough for tsunami warning. It is believed that it has potential, but changes including data transmission improvements may have to happen before real-time processing oriented to tsunami early warning is implemented on the data that is currently provided. -Tide gauge data is currently under-utilised for tsunami forecasting. Spectral analysis, modal analysis based on identified modes and arrival times extracted from the records can be useful in forecasting. -The current study is by no means exhaustive of the ways the different types of data can be used. We are only presenting an overview of what can be done. More extensive studies with each one of the types of data collected by GeoNet and other relevant networks will help improve tsunami forecasting in New Zealand.

Social and ethical issues in environmental risk management.

PubMed

Oughton, Deborah H

2011-07-01

The recognition of the social and ethical aspects of radiation risk management has been an important part of international projects following the Chernobyl accident of 1986. This study comments on the science and policy issues in environmental risk assessment, including the social and ethical dimensions of emergency preparedness and remediation experiences gained from the Chernobyl accident. While the unique situation of Fukushima, combined with an earthquake and tsunami, raises its own social and political challenges, it is hoped that some of the lessons learnt from Chernobyl will be relevant to long-term management of the Fukushima site. Copyright © 2011 SETAC.