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.

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.

Inundation Mapping and Hazard Assessment of Tectonic and Landslide Tsunamis in Southeast Alaska

NASA Astrophysics Data System (ADS)

Suleimani, E.; Nicolsky, D.; Koehler, R. D., III

2014-12-01

The Alaska Earthquake Center conducts tsunami inundation mapping for coastal communities in Alaska, and is currently focused on the southeastern region and communities of Yakutat, Elfin Cove, Gustavus and Hoonah. This activity provides local emergency officials with tsunami hazard assessment, planning, and mitigation tools. At-risk communities are distributed along several segments of the Alaska coastline, each having a unique seismic history and potential tsunami hazard. Thus, a critical component of our project is accurate identification and characterization of potential tectonic and landslide tsunami sources. The primary tectonic element of Southeast Alaska is the Fairweather - Queen Charlotte fault system, which has ruptured in 5 large strike-slip earthquakes in the past 100 years. The 1958 "Lituya Bay" earthquake triggered a large landslide into Lituya Bay that generated a 540-m-high wave. The M7.7 Haida Gwaii earthquake of October 28, 2012 occurred along the same fault, but was associated with dominantly vertical motion, generating a local tsunami. Communities in Southeast Alaska are also vulnerable to hazards related to locally generated waves, due to proximity of communities to landslide-prone fjords and frequent earthquakes. The primary mechanisms for local tsunami generation are failure of steep rock slopes due to relaxation of internal stresses after deglaciation, and failure of thick unconsolidated sediments accumulated on underwater delta fronts at river mouths. We numerically model potential tsunami waves and inundation extent that may result from future hypothetical far- and near-field earthquakes and landslides. We perform simulations for each source scenario using the Alaska Tsunami Model, which is validated through a set of analytical benchmarks and tested against laboratory and field data. Results of numerical modeling combined with historical observations are compiled on inundation maps and used for site-specific tsunami hazard assessment by emergency planners.

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.

New Maximum Tsunami Inundation Maps for Use by Local Emergency Planners in the State of California, USA

NASA Astrophysics Data System (ADS)

Wilson, R. I.; Barberopoulou, A.; Miller, K. M.; Goltz, J. D.; Synolakis, C. E.

2008-12-01

A consortium of tsunami hydrodynamic modelers, geologic hazard mapping specialists, and emergency planning managers is producing maximum tsunami inundation maps for California, covering most residential and transient populated areas along the state's coastline. The new tsunami inundation maps will be an upgrade from the existing maps for the state, improving on the resolution, accuracy, and coverage of the maximum anticipated tsunami inundation line. Thirty-five separate map areas covering nearly one-half of California's coastline were selected for tsunami modeling using the MOST (Method of Splitting Tsunami) model. From preliminary evaluations of nearly fifty local and distant tsunami source scenarios, those with the maximum expected hazard for a particular area were input to MOST. The MOST model was run with a near-shore bathymetric grid resolution varying from three arc-seconds (90m) to one arc-second (30m), depending on availability. Maximum tsunami "flow depth" and inundation layers were created by combining all modeled scenarios for each area. A method was developed to better define the location of the maximum inland penetration line using higher resolution digital onshore topographic data from interferometric radar sources. The final inundation line for each map area was validated using a combination of digital stereo photography and fieldwork. Further verification of the final inundation line will include ongoing evaluation of tsunami sources (seismic and submarine landslide) as well as comparison to the location of recorded paleotsunami deposits. Local governmental agencies can use these new maximum tsunami inundation lines to assist in the development of their evacuation routes and emergency response plans.

Building Better Volcanic Hazard Maps Through Scientific and Stakeholder Collaboration

NASA Astrophysics Data System (ADS)

Thompson, M. A.; Lindsay, J. M.; Calder, E.

2015-12-01

All across the world information about natural hazards such as volcanic eruptions, earthquakes and tsunami is shared and communicated using maps that show which locations are potentially exposed to hazards of varying intensities. Unlike earthquakes and tsunami, which typically produce one dominant hazardous phenomenon (ground shaking and inundation, respectively) volcanic eruptions can produce a wide variety of phenomena that range from near-vent (e.g. pyroclastic flows, ground shaking) to distal (e.g. volcanic ash, inundation via tsunami), and that vary in intensity depending on the type and location of the volcano. This complexity poses challenges in depicting volcanic hazard on a map, and to date there has been no consistent approach, with a wide range of hazard maps produced and little evaluation of their relative efficacy. Moreover, in traditional hazard mapping practice, scientists analyse data about a hazard, and then display the results on a map that is then presented to stakeholders. This one-way, top-down approach to hazard communication does not necessarily translate into effective hazard education, or, as tragically demonstrated by Nevado del Ruiz, Columbia in 1985, its use in risk mitigation by civil authorities. Furthermore, messages taken away from a hazard map can be strongly influenced by its visual design. Thus, hazard maps are more likely to be useful, usable and used if relevant stakeholders are engaged during the hazard map process to ensure a) the map is designed in a relevant way and b) the map takes into account how users interpret and read different map features and designs. The IAVCEI Commission on Volcanic Hazards and Risk has recently launched a Hazard Mapping Working Group to collate some of these experiences in graphically depicting volcanic hazard from around the world, including Latin America and the Caribbean, with the aim of preparing some Considerations for Producing Volcanic Hazard Maps that may help map makers in the future.

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.

Modeling of Natural Coastal Hazards in Puerto Rico in Support of Emergency Management and Coastal Planning

NASA Astrophysics Data System (ADS)

Mercado, A., Jr.

2015-12-01

The island of Puerto Rico is not only located in the so-called Caribbean hurricane alley, but is also located in a tsunami prone region. And both phenomena have affected the island. For the past few years we have undergone the task of upgrading the available coastal flood maps due to storm surges and tsunamis. This has been done taking advantage of new Lidar-derived, high resolution, topography and bathymetry and state-of-the-art models (MOST for tsunamis and ADCIRC/SWAN for storm surges). The tsunami inundation maps have been converted to evacuation maps. In tsunamis we are also working in preparing hazard maps due to tsunami currents inside ports, bays, and marinas. The storm surge maps include two scenarios of sea level rise: 0.5 and 1.0 m above Mean High Water. All maps have been adopted by the Puerto Rico State Emergency Management Agency, and are publicly available through the Internet. It is the purpose of this presentation to summarize how it has been done, the spin-off applications they have generated, and how we plan to improve coastal flooding predictions.

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

How do Japanese escape from TSUNAMI? - Disaster Prevention Education through using Hazard Maps

NASA Astrophysics Data System (ADS)

Sakaue, Hiroaki

2013-04-01

After the disaster of the earthquake and tsunami in Tohoku, Japan in 2011, it is necessary to teach more "Disaster Prevention" in school. The government guideline for education of high school geography students emphasizes improving students' awareness of disaster prevention through acquiring geographical skills, for example reading hazard and thematic maps. The working group of the Ministry of Education, Culture, Sports, Science and Technology (MEXT) says that the purpose of Disaster Prevention Education is to develop the following competencies: 1. To acquire knowledge about disasters in the local area and the science of disaster prevention. 2. To teach individuals to protect themselves from natural hazards. 3. To safely support other people in the local area. 4. To build a safe society during rebuilding from the disasters. "Disaster Prevention Education" is part of the "Education for Sustainable Development" (ESD) curriculum. That is, teaching disaster prevention can contribute to developing abilities for sustainable development and building a sustainable society. I have tried to develop a high school geography class about "tsunami". The aim of this class is to develop the students' competencies to acquire the knowledge about tsunami and protect themselves from it through reading a hazard map. I especially think that in geography class, students can protect themselves from disasters through learning the risks of disasters and how to escape when disasters occur. In the first part of class, I have taught the mechanism of tsunami formation and where tsunamis occur in Japan. In the second part of class, I have shown students pictures that I had taken in Tohoku, for instance Ishinomaki-City, Minamisanriku-Town, Kesen'numa-City, and taught how to read hazard maps that show where safe and dangerous places are when natural hazards occur. I think that students can understand the features of the local area and how to escape from disasters that may occur in local area by learning a hazard map. I have used a comment paper to evaluate the following competencies: 1. Students can understand the mechanism of tsunami formation and its potential for damage. 2. Students can read the hazard map. 3. Students can explain or describe a detailed plan for disaster prevention. In conclusion, many students could read hazard maps and describe a detailed plan for disaster prevention. In other words, through developing mapping skills, geography students can contribute to developing abilities for Disaster Prevention Education and building a sustainable society. Disaster Prevention Education has many requirements. For example, the MEXT working group says that Disaster Prevention Education teaching should not only deliver knowledge but also develop students' problem solving competency, and that it is important to incorporate this education within each subject area in the school.

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.

Spatial modelling for tsunami evacuation route in Parangtritis Village

NASA Astrophysics Data System (ADS)

Juniansah, A.; Tyas, B. I.; Tama, G. C.; Febriani, K. R.; Farda, N. M.

2018-04-01

Tsunami is a series of huge sea waves that commonly occurs because of the oceanic plate movement or tectonic activity under the sea. As a sudden hazard, the tsunami has damaged many people over the years. Parangtritis village is one of high tsunami hazard risk area in Indonesia which needs an effective tsunami risk reduction. This study aims are modelling a tsunami susceptibility map, existing assembly points evaluation, and suggesting effective evacuation routes. The susceptibility map was created using ALOS PALSAR DEM and surface roughness coefficient. The method of tsunami modelling employed inundation model developed by Berryman (2006). The results are used to determine new assembly points based on the Sentinel 2A imagery and to determine the most effective evacuation route by using network analyst. This model can be used to create detailed scale of evacuation route, but unrepresentative for assembly point that far from road network.

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.

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.

Seismic probabilistic tsunami hazard: from regional to local analysis and use of geological and historical observations

NASA Astrophysics Data System (ADS)

Tonini, R.; Lorito, S.; Orefice, S.; Graziani, L.; Brizuela, B.; Smedile, A.; Volpe, M.; Romano, F.; De Martini, P. M.; Maramai, A.; Selva, J.; Piatanesi, A.; Pantosti, D.

2016-12-01

Site-specific probabilistic tsunami hazard analyses demand very high computational efforts that are often reduced by introducing approximations on tsunami sources and/or tsunami modeling. On one hand, the large variability of source parameters implies the definition of a huge number of potential tsunami scenarios, whose omission could easily lead to important bias in the analysis. On the other hand, detailed inundation maps computed by tsunami numerical simulations require very long running time. When tsunami effects are calculated at regional scale, a common practice is to propagate tsunami waves in deep waters (up to 50-100 m depth) neglecting non-linear effects and using coarse bathymetric meshes. Then, maximum wave heights on the coast are empirically extrapolated, saving a significant amount of computational time. However, moving to local scale, such assumptions drop out and tsunami modeling would require much greater computational resources. In this work, we perform a local Seismic Probabilistic Tsunami Hazard Analysis (SPTHA) for the 50 km long coastal segment between Augusta and Siracusa, a touristic and commercial area placed along the South-Eastern Sicily coast, Italy. The procedure consists in using the outcomes of a regional SPTHA as input for a two-step filtering method to select and substantially reduce the number of scenarios contributing to the specific target area. These selected scenarios are modeled using high resolution topo-bathymetry for producing detailed inundation maps. Results are presented as probabilistic hazard curves and maps, with the goal of analyze, compare and highlight the different results provided by regional and local hazard assessments. Moreover, the analysis is enriched by the use of local observed tsunami data, both geological and historical. Indeed, tsunami data-sets available for the selected target areas are particularly rich with respect to the scarce and heterogeneous data-sets usually available elsewhere. Therefore, they can represent valuable benchmarks for testing and strengthening the results of such kind of studies. The work is funded by the Italian Flagship Project RITMARE, the two EC FP7 projects ASTARTE (Grant agreement 603839) and STREST (Grant agreement 603389), and the INGV-DPC Agreement.

Tsunami hazard assessment along the U. S. East Coast

NASA Astrophysics Data System (ADS)

Tajalli Bakhsh, T.; Grilli, S. T.; Harris, J. C.; Kirby, J. T.; Shi, F.; Tehranirad, B.

2012-12-01

In 2005, the National Tsunami Hazard Mitigation Program (NTHMP) was tasked by Congress to develop tsunami inundation maps for the entire US coastline. This work provides an overview of the modeling work related to the development inundation maps along the US east coast. In this region the paucity of historical tsunami records and lack of paleotsunami observations yields a large uncertainty on the source and magnitude of potential extreme tsunami events, and their related coastal hazard. In the Atlantic Ocean basin significant tsunami hazard may result from far-field earthquakes, such as a repeat of the M8.9 Lisbon 1755 event in the Azores convergence zone, or a hypothetical extreme M9 earthquake in the Puerto Rico Trench (PRT). Additionally, it is believed that a repeat of one of the large historical collapses, identified at the toe of the Cumbre Vieja volcano on La Palma (Canary Islands; i.e., with a maximum volume of 450 km3), could pose a major tsunami hazard to the entire US east coast. Finally, in the near-field, large submarine mass failure (SMF) scars have been mapped by USGS, particularly North of the Carolinas (e.g., Currituck), which are believed to have caused past tsunamis. Large SMFs can be triggered by moderate seismicity (M7 or so), such as can occur on the east coast. In fact, one of the few historical tsunamis that significantly affected this region was caused by the 1929 Grand Bank underwater slide, which was triggered by a M7.2 earthquake. In this work we identify and parameterize all potential tsunami sources affecting the US east coast, and perform simulations of tsunami generation, propagation, and coastal impact in a series of increasingly resolved nested grids. Following this methodology, tsunami inundation maps are currently being developed for a few of the most affected areas. In simulations, we use a robust and well-validated Fully Nonlinear Boussinesq long-wave model (FUNWAVE-TVD), on Cartesian or spherical grids. Coseismic tsunami sources are modeled using the standard Okada method. For landslide tsunamis, we first generate tsunami sources using a three-dimensional Navier-Stokes model (THETIS or NHWAVE). These models feature all relevant physical processes, such as frequency dispersion (very important for landslide sources), nonlinear wave effects during shoaling, and dissipation by bottom friction and wave breaking (via a shock-capturing TVD algorithm). In modeling coastal hazard from various sources, we find that tsunamigenic SMFs, which are the nearest tsunami sources and can potentially cause highly focused coastal runup, may control tsunami hazard for many east coast communities north of the Carolinas. In many cases, however, we find that a wide shallow continental shelf may cause significant dissipation of the shorter waves caused by SMFs and hence offer some protection. The accurate modeling of the delicate balance between nonlinear and dissipative processes governing such situations is currently being researched and will be the object of a separate presentation. Additionally, considerable efforts are being devoted to properly parameterizing extreme SMFs, which are also the object of collaborative work with geologists and marine geotechnical experts (reported independently).

Publications - DDS 10 | Alaska Division of Geological & Geophysical Surveys

Science.gov Websites

Portal Climate and Cryosphere Hazards Coastal Hazards Program Guide to Geologic Hazards in Alaska Products Interactive Interactive Map Alaska Tsunami Inundation Maps Keywords Coastal and River; Geologic

New Tsunami Inundation Maps for California

NASA Astrophysics Data System (ADS)

Barberopoulou, Aggeliki; Borrero, Jose; Uslu, Burak; Kanoglu, Utku; Synolakis, Costas

2010-05-01

California is the first US State to complete its tsunami inundation mapping. A new generation of tsunami inundation maps is now available for 17 coastal counties.. The new maps offer improved coverage for many areas, they are based on the most recent descriptions of potential tsunami farfield and nearfield sources and use the best available bathymetric and topographic data for modelling. The need for new tsunami maps for California became clear since Synolakis et al (1998) described how inundation projections derived with inundation models that fully calculate the wave evolution over dry land can be as high as twice the values predicted with earlier threshold models, for tsunamis originating from tectonic source. Since the 1998 Papua New Guinea tsunami when the hazard from offshore submarine landslides was better understood (Bardet et al, 2003), the State of California funded the development of the first generation of maps, based on local tectonic and landslide sources. Most of the hazard was dominated by offshore landslides, whose return period remains unknown but is believed to be higher than 1000 years for any given locale, at least in Southern California. The new generation of maps incorporates local and distant scenarios. The partnership between the Tsunami Research Center at USC, the California Emergency Management Agency and the California Seismic Safety Commission let the State to be the first among all US States to complete the maps. (Exceptions include the offshore islands and Newport Beach, where higher resolution maps are under way). The maps were produced with the lowest cost per mile of coastline, per resident or per map than all other States, because of the seamless integration of the USC and NOAA databases and the use of the MOST model. They are a significant improvement over earlier map generations. As part of a continuous improvement in response, mitigation and planning and community education, the California inundation maps can contribute in reducing tsunami risk. References -Bardet, JP et al (2003), Landslide tsunamis: Recent findings and research directions, Pure and Applied Geophysics, 160, (10-11), 1793-1809. -Eisner, R., Borrero, C., Synolakis, C.E. (2001) Inundation Maps for the State of California, International Tsunami Symposium, ITS 2001 Proceedings, NHTMP Review Paper #4, 67-81. -Synolakis, C.E., D. McCarthy, V.V. Titov, J.C. Borrero, (1998) Evaluating the Tsunami Risk in California, CALIFORNIA AND THE WORLD OCEAN '97, 1225-1236, Proceedings ASCE, ISBN: 0-7844-0297-3.

Mapping Coastal Flood Zones for the National Flood Insurance Program

NASA Astrophysics Data System (ADS)

Carlton, D.; Cook, C. L.; Weber, J.

2004-12-01

The National Flood Insurance Program (NFIP) was created by Congress in 1968, and significantly amended in 1973 to reduce loss of life and property caused by flooding, reduce disaster relief costs caused by flooding and make Federally backed flood insurance available to property owners. These goals were to be achieved by requiring building to be built to resist flood damages, guide construction away from flood hazards, and transferring the cost of flood losses from taxpayers to policyholders. Areas subject to flood hazards were defined as those areas that have a probability greater than 1 percent of being inundated in any given year. Currently over 19,000 communities participate in the NFIP, many of them coastal communities subject to flooding from tides, storm surge, waves, or tsunamis. The mapping of coastal hazard areas began in the early 1970's and has been evolving ever since. At first only high tides and storm surge were considered in determining the hazardous areas. Then, after significant wave caused storm damage to structures outside of the mapped hazard areas wave hazards were also considered. For many years FEMA has had Guidelines and Specifications for mapping coastal hazards for the East Coast and the Gulf Coast. In September of 2003 a study was begun to develop similar Guidelines and Specifications for the Pacific Coast. Draft Guidelines and Specifications will be delivered to FEMA by September 30, 2004. During the study tsunamis were identified as a potential source of a 1 percent flood event on the West Coast. To better understand the analytical results, and develop adequate techniques to estimate the magnitude of a tsunami with a 1 percent probability of being equaled or exceeded in any year, a pilot study has begun at Seaside Oregon. Both the onshore velocity and the resulting wave runup are critical functions for FEMA to understand and potentially map. The pilot study is a cooperative venture between NOAA and USGS that is partially funded by both agencies and by FEMA. The results of the pilot study will help FEMA determine when tsunamis should be considered in mapping coastal hazards, how to predict their impact, how they should be mapped and possibly the construction standards for zones mapped as having a 1 percent or greater chance of suffering a tsunami.

Implementation of tsunami disaster prevention measures in the municipality of San Rafael del Sur, Nicaragua

NASA Astrophysics Data System (ADS)

Strauch, W.; Talavera, E.; Acosta, N.; Sanchez, M.; Mejia, E.

2007-05-01

The Nicaraguan Pacific coast presents considerable tsunami risk. On September 1, 1992, a tsunami caused enormous damage in the infrastructure and killed more than 170 people. A pilot project was conducted between 2006 and 2007 in the municipality of San Rafel del Sur, area of Masachapa, The project included multiple topics of tsunami prevention measures and considering the direct participation of the local population, as: -General education on disaster prevention, participative events; -Investigation of awareness level and information needs for different population groups; -Specific educational measures in the schools; -Publication of brochures, calendars, news paper articles, radio programs, TV spots -Development of local tsunami hazard maps, 1:5,000 scale; (based on previous regional tsunami hazard mapping projects and local participation) -Development of a tsunami warning plan; -Improvements of the national tsunami warning system. -Installation of sirens for tsunami warning -Installation of tsunami signs, indicating hazardous areas, evacuation routes, safe places; -Realization of evacuation drills in schools. Based on the experiences gained in Masachapa it is planned to run similar projects in other areas along the Nicaraguan Pacific coast. In the project participated the local municipality and local stakeholders of San Rafael del Sur, Ministry of Education, National Police, Nicaraguan Red Cross, Ministry of Health, Ministry of Tourism, Nicaraguan Geosciences Institute (INETER), National System for Disaster Prevention (SINAPRED), Swiss Agency for Development and Cooperation (SDC). It was financed by SDC and INETER.

Preliminary Seismic Probabilistic Tsunami Hazard Map for Italy

NASA Astrophysics Data System (ADS)

Lorito, Stefano; Selva, Jacopo; Basili, Roberto; Grezio, Anita; Molinari, Irene; Piatanesi, Alessio; Romano, Fabrizio; Tiberti, Mara Monica; Tonini, Roberto; Bonini, Lorenzo; Michelini, Alberto; Macias, Jorge; Castro, Manuel J.; González-Vida, José Manuel; de la Asunción, Marc

2015-04-01

We present a preliminary release of the first seismic probabilistic tsunami hazard map for Italy. The map aims to become an important tool for the Italian Department of Civil Protection (DPC), as well as a support tool for the NEAMTWS Tsunami Service Provider, the Centro Allerta Tsunami (CAT) at INGV, Rome. The map shows the offshore maximum tsunami elevation expected for several average return periods. Both crustal and subduction earthquakes are considered. The probability for each scenario (location, depth, mechanism, source size, magnitude and temporal rate) is defined on a uniform grid covering the entire Mediterranean for crustal earthquakes and on the plate interface for subduction earthquakes. Activity rates are assigned from seismic catalogues and basing on a tectonic regionalization of the Mediterranean area. The methodology explores the associated aleatory uncertainty through the innovative application of an Event Tree. Main sources of epistemic uncertainty are also addressed although in preliminary way. The whole procedure relies on a database of pre-calculated Gaussian-shaped Green's functions for the sea level elevation, to be used also as a real time hazard assessment tool by CAT. Tsunami simulations are performed using the non-linear shallow water multi-GPU code HySEA, over a 30 arcsec bathymetry (from the SRTM30+ dataset) and the maximum elevations are stored at the 50-meter isobath and then extrapolated through the Green's law at 1 meter depth. This work is partially funded by project ASTARTE - Assessment, Strategy And Risk Reduction for Tsunamis in Europe - FP7-ENV2013 6.4-3, Grant 603839, and by the Italian flagship project RITMARE.

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.

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.

Seismic and tsunami hazard in Puerto Rico and the Virgin Islands

USGS Publications Warehouse

Dillon, William P.; Frankel, Arthur D.; Mueller, Charles S.; Rodriguez, Rafael W.; ten Brink, Uri S.

1999-01-01

Executive SummaryPuerto Rico and the Virgin Islands are located at an active plate boundary between the North American plate and the northeast corner of the Caribbean plate. The region was subject in historical times to large magnitude earthquakes and devastating tsunamis. A major downward tilt of the sea floor north of Puerto Rico and the Virgin Islands, large submarine rockslides, and an unusually large negative gravity anomaly are also indicative of a tectonically active region. Scientists have so far failed to explain the deformation of this region in a coherent and predictable picture, such as in California, and this has hampered their ability to assess seismic and tsunami hazards in the region. The NE corner of the Caribbean is unique among the seismically-active regions of the United States in that it is mostly covered by water. This fact presents an additional challenge for seismic and tsunami hazard assessment and mitigation.The workshop, convened in San Juan on March 23-24, 1999, was "historic" in that it brought together for the first time a broad spectrum of scientists, engineers, and public and private sector officials who deal with such diverse questions as tectonic models, probabilistic assessment of seismic hazard, prediction of tsunami runup, strong ground motion, building codes, stability of man-made structures, and the public’s preparedness for natural disasters. It was an opportunity for all the participants to find out how their own activity fit into the broad picture of science and how it aids society in hazard assessment and mitigation. In addition, the workshop was offered as a continuing education course at the Colegio de Ingenieros y Agrimensores de Puerto Rico, which assured a rapid dissemination of the results to the local community. A news conference which took place during the workshop alerted the public to the efforts of the USGS, other Federal agencies, the Commonwealth of Puerto Rico, universities and the private sector.During the first day of the workshop, participants from universities, federal institutions, and consulting firms in Puerto Rico, the Virgin Islands, the continental U.S., Dominican Republic, and Europe reviewed the present state of knowledge including a review and discussion of present plate models, recent GPS and seismic reflection data, seismicity, paleoseismology, and tsunamis. The state of earthquake/tsunami studies in Puerto Rico was presented by several faculty members from the University of Puerto Rico at Mayaguez. A preliminary seismic hazard map was presented by the USGS and previous hazard maps and economic loss assessments were considered. During the second day, the participants divided into working groups and prepared specific recommendations for future activities in the region along the six following topics below. Highlights of these recommended activities are:Marine geology and geophysics – Acquire deep-penetration seismic reflection and refraction data, deploy temporary ocean bottom seismometer arrays to record earthquakes, collect high-resolution multibeam bathymetry and side scan sonar data of the region, and in particular, the near shore region, and conduct focussed high-resolution seismic studies around faults. Determine slip rates of specific offshore faults. Assemble a GIS database for available marine geological and geophysical data.Paleoseismology and active faults - Field reconnaissance aimed at identifying Quaternary faults and determining their paleoseismic chronology and slip rates, as well as identifying and dating paleoliquefaction features from large earthquakes. Quaternary mapping of marine terraces, fluvial terraces and basins, beach ridges, etc., to establish framework for understanding neotectonic deformation of the island. Interpretation of aerial photography to identify possible Quaternary faults.Earthquake seismology – Determine an empirical seismic attenuation function using observations from local seismic networks and recently-installed broad-band stations. Evaluate existing earthquake catalogs from local networks and regional stations, complete the catalogs. Transcribe the pre-1991 network data from 9-track tape onto more stable archival media. Calibrate instruments of local networks. Use GPS measurement to constrain deformation rates used in seismic-hazard maps.Engineering – Prepare liquefaction susceptibility maps for the urban areas. Update and improve databases for types of site conditions. Collect site effect observations and near-surface geophysical measurements for future local (urban-area) hazard maps. Expand the number of instruments in the strong motion program. Develop fragility curves for Puerto Rico construction types and details, and carry out laboratory testing on selected types of mass-produced construction. Consider tsunami design in shoreline construction projects.Tsunami hazard - Extract tsunami observations from archives and develop a Caribbean historical tsunami database. Analyze prehistoric tsunami deposits. Collect accurate, up-to-date, near-shore topography and bathymetry for accurate inundation models. Prepare tsunami flooding and evacuation maps. Establish a Caribbean Tsunami Warning System for Puerto Rico and the Virgin Islands. Evaluate local, regional, national, and global seismic networks and equipment, and their role in a tsunami warning system.Societal concerns – Prepare warning messages, protocols, and evacuation routes for earthquake, tsunami, and landslide hazards for Puerto Rico and the U.S. Virgin Islands. Advocate enforcement of existing building codes. Prepare non-technical hazard assessment maps for political and educational uses. Raise the awareness of potentially affected populations by presentations at elementary schools, by the production of a tsunami video, and by distribution of earthquake preparedness manuals in newspaper supplements. Promote partnerships at state and federal level for long-term earthquake and tsunami hazard mitigation. This partnership should also include the private sector such as the insurance industry, telecommunication companies, and the engineering community.The following reports of the various working groups are the cumulative recommendations of the community of scientists, engineers, and public officials, who participated in the workshop. The list of participants and the workshop’s agenda are given in the appendix.Marine and Geology and Geophysics Working GroupPaleoseismology and Active Faults Working GroupJoint Working Group for Earthquake Seismology and EngineeringTsunami Working GroupSocietal Concerns Working Group

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.

Analysis of tsunami disaster map by Geographic Information System (GIS): Aceh Singkil-Indonesia

NASA Astrophysics Data System (ADS)

Farhan, A.; Akhyar, H.

2017-02-01

Tsunami risk map is used by stakeholder as a base to decide evacuation plan and evaluates from disaster. Aceh Singkil district of Aceh- Indonesia’s disaster maps have been developed and analyzed by using GIS tool. Overlay methods through algorithms are used to produce hazard map, vulnerability, capacity and finally created disaster risk map. Spatial maps are used topographic maps, administrative map, SRTM. The parameters are social, economic, physical environmental vulnerability, a level of exposed people, parameters of houses, public building, critical facilities, productive land, population density, sex ratio, poor ratio, disability ratio, age group ratio, the protected forest, natural forest, and mangrove forest. The results show high-risk tsunami disaster at nine villages; moderate levels are seventeen villages, and other villages are shown in the low level of tsunami risk disaster.

Probabilistic tsunami hazard assessment at Seaside, Oregon, for near-and far-field seismic sources

USGS Publications Warehouse

Gonzalez, F.I.; Geist, E.L.; Jaffe, B.; Kanoglu, U.; Mofjeld, H.; Synolakis, C.E.; Titov, V.V.; Areas, D.; Bellomo, D.; Carlton, D.; Horning, T.; Johnson, J.; Newman, J.; Parsons, T.; Peters, R.; Peterson, C.; Priest, G.; Venturato, A.; Weber, J.; Wong, F.; Yalciner, A.

2009-01-01

The first probabilistic tsunami flooding maps have been developed. The methodology, called probabilistic tsunami hazard assessment (PTHA), integrates tsunami inundation modeling with methods of probabilistic seismic hazard assessment (PSHA). Application of the methodology to Seaside, Oregon, has yielded estimates of the spatial distribution of 100- and 500-year maximum tsunami amplitudes, i.e., amplitudes with 1% and 0.2% annual probability of exceedance. The 100-year tsunami is generated most frequently by far-field sources in the Alaska-Aleutian Subduction Zone and is characterized by maximum amplitudes that do not exceed 4 m, with an inland extent of less than 500 m. In contrast, the 500-year tsunami is dominated by local sources in the Cascadia Subduction Zone and is characterized by maximum amplitudes in excess of 10 m and an inland extent of more than 1 km. The primary sources of uncertainty in these results include those associated with interevent time estimates, modeling of background sea level, and accounting for temporal changes in bathymetry and topography. Nonetheless, PTHA represents an important contribution to tsunami hazard assessment techniques; viewed in the broader context of risk analysis, PTHA provides a method for quantifying estimates of the likelihood and severity of the tsunami hazard, which can then be combined with vulnerability and exposure to yield estimates of tsunami risk. Copyright 2009 by the American Geophysical Union.

The Role of Earth Science in Oregon’s Tsunami Preparedness (Invited)

NASA Astrophysics Data System (ADS)

Priest, G. R.

2009-12-01

Earth science played a critical role in understanding the scope of Oregon’s tsunami hazard. When in the early 1990’s earth scientists communicated to stakeholders the seriousness of the threat posed by local Cascadia subduction zone tsunamis, tsunami preparedness began to rise in priority at all levels of government. Hard field evidence in the form of prehistoric tsunami deposits was a critical component in making the hazard “real” to local governments. State-produced tsunami inundation maps derived from numerical simulations gave decision makers and educators reliable tools to illustrate the spatial scope of the hazard. These maps allowed local cities to plan for evacuation and empowered the State of Oregon to begin “hard” mitigation by limiting new construction of critical facilities seaward of a regulatory inundation line. “Entering” and “Leaving” tsunami hazard zone signs were placed along the Oregon Coast Highway where it dips below this inundation line as means of raising awareness of both the local and transient populations. When detailed inundation studies and derivative evacuation maps were produced for individual communities, State scientists sought advice from local officials at every stage, giving them ownership of the final products. This sense of ownership gave decision makers much greater confidence in the maps and turned many skeptics into passionate advocates. This network of advocates has, over time, resulted in local jurisdictions taking substantive preparedness actions such as replacing critical evacuation bridges, starting networks of emergency response volunteers, and moving critical structures like schools and fire stations. One place that earth science has some difficulty is in communicating probability and uncertainty. For example, the State of Oregon is currently producing new maps that depict uncertainty of tsunami flooding from a future Cascadia subduction zone earthquake. These maps show a range of inundation lines that reflect the relative confidence level (percentage) that a local Cascadia tsunami will NOT exceed each line. In the first of these studies at Cannon Beach, Oregon (Priest et al., 2009) the 90th percentile flood level was only about half to two-thirds as high as the 99th percentile. On the northern Oregon coast Cascadia recurrence is ~500 years, so a percentile map depicts spatial uncertainty of inundation for that event. A Cascadia tsunami approximating the 99th percentile confidence level is no doubt a rare event, but how rare we really do not know. We suspect from offshore turbidite data that only one of these extreme events may have occurred in the last 10,000 years. When the map and underlying data were presented to local officials, they had some difficulty in understanding how to use the information. Erring on the side of caution, they chose the 99th percentile line for evacuation planning but this decision greatly limited available evacuation sites. Cost may make a similarly conservative decision inappropriate for use in building codes or for design of vertical evacuation structures. REFERENCE Priest, G.R.; Goldfinger C.; Wang, K.; Witter, R.C.; Zhang; Y., Baptista, A.M. (2009) Tsunami hazard assessment of the Northern Oregon coast: a multi-deterministic approach tested at Cannon Beach, Clatsop County, Oregon. Oregon Dept. Geol. Mineral Industries Special Paper 41.

Probabilistic Tsunami Hazard Assessment: the Seaside, Oregon Pilot Study

NASA Astrophysics Data System (ADS)

Gonzalez, F. I.; Geist, E. L.; Synolakis, C.; Titov, V. V.

2004-12-01

A pilot study of Seaside, Oregon is underway, to develop methodologies for probabilistic tsunami hazard assessments that can be incorporated into Flood Insurance Rate Maps (FIRMs) developed by FEMA's National Flood Insurance Program (NFIP). Current NFIP guidelines for tsunami hazard assessment rely on the science, technology and methodologies developed in the 1970s; although generally regarded as groundbreaking and state-of-the-art for its time, this approach is now superseded by modern methods that reflect substantial advances in tsunami research achieved in the last two decades. In particular, post-1990 technical advances include: improvements in tsunami source specification; improved tsunami inundation models; better computational grids by virtue of improved bathymetric and topographic databases; a larger database of long-term paleoseismic and paleotsunami records and short-term, historical earthquake and tsunami records that can be exploited to develop improved probabilistic methodologies; better understanding of earthquake recurrence and probability models. The NOAA-led U.S. National Tsunami Hazard Mitigation Program (NTHMP), in partnership with FEMA, USGS, NSF and Emergency Management and Geotechnical agencies of the five Pacific States, incorporates these advances into site-specific tsunami hazard assessments for coastal communities in Alaska, California, Hawaii, Oregon and Washington. NTHMP hazard assessment efforts currently focus on developing deterministic, "credible worst-case" scenarios that provide valuable guidance for hazard mitigation and emergency management. The NFIP focus, on the other hand, is on actuarial needs that require probabilistic hazard assessments such as those that characterize 100- and 500-year flooding events. There are clearly overlaps in NFIP and NTHMP objectives. NTHMP worst-case scenario assessments that include an estimated probability of occurrence could benefit the NFIP; NFIP probabilistic assessments of 100- and 500-yr events could benefit the NTHMP. The joint NFIP/NTHMP pilot study at Seaside, Oregon is organized into three closely related components: Probabilistic, Modeling, and Impact studies. Probabilistic studies (Geist, et al., this session) are led by the USGS and include the specification of near- and far-field seismic tsunami sources and their associated probabilities. Modeling studies (Titov, et al., this session) are led by NOAA and include the development and testing of a Seaside tsunami inundation model and an associated database of computed wave height and flow velocity fields. Impact studies (Synolakis, et al., this session) are led by USC and include the computation and analyses of indices for the categorization of hazard zones. The results of each component study will be integrated to produce a Seaside tsunami hazard map. This presentation will provide a brief overview of the project and an update on progress, while the above-referenced companion presentations will provide details on the methods used and the preliminary results obtained by each project component.

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.

Numerical modeling of marine Gravity data for tsunami hazard zone mapping

NASA Astrophysics Data System (ADS)

Porwal, Nipun

2012-07-01

Tsunami is a series of ocean wave with very high wavelengths ranges from 10 to 500 km. Therefore tsunamis act as shallow water waves and hard to predict from various methods. Bottom Pressure Recorders of Poseidon class considered as a preeminent method to detect tsunami waves but Acoustic Modem in Ocean Bottom Pressure (OBP) sensors placed in the vicinity of trenches having depth of more than 6000m fails to propel OBP data to Surface Buoys. Therefore this paper is developed for numerical modeling of Gravity field coefficients from Bureau Gravimetric International (BGI) which do not play a central role in the study of geodesy, satellite orbit computation, & geophysics but by mathematical transformation of gravity field coefficients using Normalized Legendre Polynomial high resolution ocean bottom pressure (OBP) data is generated. Real time sea level monitored OBP data of 0.3° by 1° spatial resolution using Kalman filter (kf080) for past 10 years by Estimating the Circulation and Climate of the Ocean (ECCO) has been correlated with OBP data from gravity field coefficients which attribute a feasible study on future tsunami detection system from space and in identification of most suitable sites to place OBP sensors near deep trenches. The Levitus Climatological temperature and salinity are assimilated into the version of the MITGCM using the ad-joint method to obtain the sea height segment. Then TOPEX/Poseidon satellite altimeter, surface momentum, heat, and freshwater fluxes from NCEP reanalysis product and the dynamic ocean topography DOT_DNSCMSS08_EGM08 is used to interpret sea-bottom elevation. Then all datasets are associated under raster calculator in ArcGIS 9.3 using Boolean Intersection Algebra Method and proximal analysis tools with high resolution sea floor topographic map. Afterward tsunami prone area and suitable sites for set up of BPR as analyzed in this research is authenticated by using Passive microwave radiometry system for Tsunami Hazard Zone Mapping by network of seismometers. Thus using such methodology for early Tsunami Hazard Zone Mapping also increase accuracy and reduce time period for tsunami predictions. KEYWORDS:, Tsunami, Gravity Field Coefficients, Ocean Bottom Pressure, ECCO, BGI, Sea Bottom Temperature, Sea Floor Topography.

Beat-the-wave evacuation mapping for tsunami hazards in Seaside, Oregon, USA

USGS Publications Warehouse

Priest, George R.; Stimely, Laura; Wood, Nathan J.; Madin, Ian; Watzig, Rudie

2016-01-01

Previous pedestrian evacuation modeling for tsunamis has not considered variable wave arrival times or critical junctures (e.g., bridges), nor does it effectively communicate multiple evacuee travel speeds. We summarize an approach that identifies evacuation corridors, recognizes variable wave arrival times, and produces a map of minimum pedestrian travel speeds to reach safety, termed a “beat-the-wave” (BTW) evacuation analysis. We demonstrate the improved approach by evaluating difficulty of pedestrian evacuation of Seaside, Oregon, for a local tsunami generated by a Cascadia subduction zone earthquake. We establish evacuation paths by calculating the least cost distance (LCD) to safety for every grid cell in a tsunami-hazard zone using geospatial, anisotropic path distance algorithms. Minimum BTW speed to safety on LCD paths is calculated for every grid cell by dividing surface distance from that cell to safety by the tsunami arrival time at safety. We evaluated three scenarios of evacuation difficulty: (1) all bridges are intact with a 5-minute evacuation delay from the start of earthquake, (2) only retrofitted bridges are considered intact with a 5-minute delay, and (3) only retrofitted bridges are considered intact with a 10-minute delay. BTW maps also take into account critical evacuation points along complex shorelines (e.g., peninsulas, bridges over shore-parallel estuaries) where evacuees could be caught by tsunami waves. The BTW map is able to communicate multiple pedestrian travel speeds, which are typically visualized by multiple maps with current LCD-based mapping practices. Results demonstrate that evacuation of Seaside is problematic seaward of the shore-parallel waterways for those with any limitations on mobility. Tsunami vertical-evacuation refuges or additional pedestrian bridges may be effective ways of reducing loss of life seaward of these waterways.

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.

Scenario based tsunami wave height estimation towards hazard evaluation for the Hellenic coastline and examples of extreme inundation zones in South Aegean

NASA Astrophysics Data System (ADS)

Melis, Nikolaos S.; Barberopoulou, Aggeliki; Frentzos, Elias; Krassanakis, Vassilios

2016-04-01

A scenario based methodology for tsunami hazard assessment is used, by incorporating earthquake sources with the potential to produce extreme tsunamis (measured through their capacity to cause maximum wave height and inundation extent). In the present study we follow a two phase approach. In the first phase, existing earthquake hazard zoning in the greater Aegean region is used to derive representative maximum expected earthquake magnitude events, with realistic seismotectonic source characteristics, and of greatest tsunamigenic potential within each zone. By stacking the scenario produced maximum wave heights a global maximum map is constructed for the entire Hellenic coastline, corresponding to all expected extreme offshore earthquake sources. Further evaluation of the produced coastline categories based on the maximum expected wave heights emphasizes the tsunami hazard in selected coastal zones with important functions (i.e. touristic crowded zones, industrial zones, airports, power plants etc). Owing to its proximity to the Hellenic Arc, many urban centres and being a popular tourist destination, Crete Island and the South Aegean region are given a top priority to define extreme inundation zoning. In the second phase, a set of four large coastal cities (Kalamata, Chania, Heraklion and Rethymno), important for tsunami hazard, due i.e. to the crowded beaches during the summer season or industrial facilities, are explored towards preparedness and resilience for tsunami hazard in Greece. To simulate tsunamis in the Aegean region (generation, propagation and runup) the MOST - ComMIT NOAA code was used. High resolution DEMs for bathymetry and topography were joined via an interface, specifically developed for the inundation maps in this study and with similar products in mind. For the examples explored in the present study, we used 5m resolution for the topography and 30m resolution for the bathymetry, respectively. Although this study can be considered as preliminary, it can also form the basis to further develop a scenario based inundation model database that can be used as an operational tool, for fast assessing tsunami prone zones during a real tsunami crisis.

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.

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.

Washington Tsunami Hazard Mitigation Program

NASA Astrophysics Data System (ADS)

Walsh, T. J.; Schelling, J.

2012-12-01

Washington State has participated in the National Tsunami Hazard Mitigation Program (NTHMP) since its inception in 1995. We have participated in the tsunami inundation hazard mapping, evacuation planning, education, and outreach efforts that generally characterize the NTHMP efforts. We have also investigated hazards of significant interest to the Pacific Northwest. The hazard from locally generated earthquakes on the Cascadia subduction zone, which threatens tsunami inundation in less than hour following a magnitude 9 earthquake, creates special problems for low-lying accretionary shoreforms in Washington, such as the spits of Long Beach and Ocean Shores, where high ground is not accessible within the limited time available for evacuation. To ameliorate this problem, we convened a panel of the Applied Technology Council to develop guidelines for construction of facilities for vertical evacuation from tsunamis, published as FEMA 646, now incorporated in the International Building Code as Appendix M. We followed this with a program called Project Safe Haven (http://www.facebook.com/ProjectSafeHaven) to site such facilities along the Washington coast in appropriate locations and appropriate designs to blend with the local communities, as chosen by the citizens. This has now been completed for the entire outer coast of Washington. In conjunction with this effort, we have evaluated the potential for earthquake-induced ground failures in and near tsunami hazard zones to help develop cost estimates for these structures and to establish appropriate tsunami evacuation routes and evacuation assembly areas that are likely to to be available after a major subduction zone earthquake. We intend to continue these geotechnical evaluations for all tsunami hazard zones in Washington.

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.

Climatic Changes and Consequences on the French West Indies (C3AF), Hurricane and Tsunami Hazards Assessment

NASA Astrophysics Data System (ADS)

Arnaud, G.; Krien, Y.; Zahibo, N.; Dudon, B.

2017-12-01

Coastal hazards are among the most worrying threats of our time. In a context of climate change coupled to a large population increase, tropical areas could be the most exposed zones of the globe. In such circumstances, understanding the underlying processes can help to better predict storm surges and the associated global risks.Here we present the partial preliminary results integrated in a multidisciplinary project focused on climatic change effects over the coastal threat in the French West Indies and funded by the European Regional Development Fund. The study aims to provide a coastal hazard assessment based on hurricane surge and tsunami modeling including several aspects of climate changes that can affect hazards such as sea level rise, crustal subsidence/uplift, coastline changes etc. Several tsunamis scenarios have been simulated including tele-tsunamis to ensure a large range of tsunami hazards. Surge level of hurricane have been calculated using a large number of synthetic hurricanes to cover the actual and forecasted climate over the tropical area of Atlantic ocean. This hazard assessment will be later coupled with stakes assessed over the territory to provide risk maps.

Identification of elements at risk for a credible tsunami event for Istanbul

NASA Astrophysics Data System (ADS)

Hancilar, U.

2012-01-01

Physical and social elements at risk are identified for a credible tsunami event for Istanbul. For this purpose, inundation maps resulting from probabilistic tsunami hazard analysis for a 10% probability of exceedance in 50 yr are utilised in combination with the geo-coded inventories of building stock, lifeline systems and demographic data. The built environment on Istanbul's shorelines that is exposed to tsunami inundation comprises residential, commercial, industrial, public (governmental/municipal, schools, hospitals, sports and religious), infrastructure (car parks, garages, fuel stations, electricity transformer buildings) and military buildings, as well as piers and ports, gas tanks and stations and other urban elements (e.g., recreational facilities). Along the Marmara Sea shore, Tuzla shipyards and important port and petrochemical facilities at Ambarlı are expected to be exposed to tsunami hazard. Significant lifeline systems of the city of Istanbul such as natural gas, electricity, telecommunication and sanitary and waste-water transmission, are also under the threat of tsunamis. In terms of social risk, it is estimated that there are about 32 000 inhabitants exposed to tsunami hazard.

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.

The Making of a Tsunami Hazard Map: Lessons Learned from the TSUMAPS-NEAM Project

NASA Astrophysics Data System (ADS)

Basili, R.

2017-12-01

Following the worldwide surge of awareness toward tsunami hazard and risk in the last decade, Europe has promoted a better understanding of the tsunami phenomenon through research projects (e.g. TRANSFER, ASTARTE) and started programs for preventing the tsunami impact along the coastlines of the North-East Atlantic, the Mediterranean, and connected Seas (NEAM) region (e.g. the Tsunami Early Warning and Mitigation System, NEAMTWS, coordinated by IOC/UNESCO). An indispensable tool toward long-term coastal planning and an effective design and subsequent use of TWS is the availability of a comprehensive Probabilistic Tsunami Hazard Assessment (PTHA). The TSUMAPS-NEAM project took the pledge of producing the first region-wide long-term homogenous PTHA map from earthquake sources. The hazard assessment was built upon state-of-the-art procedures and standards, enriched by some rather innovative/experimental approaches such as: (1) the statistical treatment of potential seismic sources, combining all the available information (seismicity, moment tensors, tectonics), and considering earthquakes occurring on major crustal faults and subduction interfaces; (2) an intensive computational approach to tsunami generation and linear propagation across the sea up to an offshore fixed depth; (3) the use of approximations for shoaling and inundation, based on local bathymetry, and for tidal stages; and (4) the exploration of several alternatives for the basic input data and their parameters which produces a number of models that are treated through an ensemble uncertainty quantification. This presentation will summarize the TSUMAPS-NEAM project goals, implementation, and achieved results, as well as the humps and bumps we run into during its development. The TSUMAPS-NEAM Project (http://www.tsumaps-neam.eu/) is co-financed by the European Union Civil Protection Mechanism, Agreement Number: ECHO/SUB/2015/718568/PREV26.

Using Multi-Scenario Tsunami Modelling Results combined with Probabilistic Analyses to provide Hazard Information for the South-WestCoast of Indonesia

NASA Astrophysics Data System (ADS)

Zosseder, K.; Post, J.; Steinmetz, T.; Wegscheider, S.; Strunz, G.

2009-04-01

Indonesia is located at one of the most active geological subduction zones in the world. Following the most recent seaquakes and their subsequent tsunamis in December 2004 and July 2006 it is expected that also in the near future tsunamis are likely to occur due to increased tectonic tensions leading to abrupt vertical seafloor alterations after a century of relative tectonic silence. To face this devastating threat tsunami hazard maps are very important as base for evacuation planning and mitigation strategies. In terms of a tsunami impact the hazard assessment is mostly covered by numerical modelling because the model results normally offer the most precise database for a hazard analysis as they include spatially distributed data and their influence to the hydraulic dynamics. Generally a model result gives a probability for the intensity distribution of a tsunami at the coast (or run up) and the spatial distribution of the maximum inundation area depending on the location and magnitude of the tsunami source used. The boundary condition of the source used for the model is mostly chosen by a worst case approach. Hence the location and magnitude which are likely to occur and which are assumed to generate the worst impact are used to predict the impact at a specific area. But for a tsunami hazard assessment covering a large coastal area, as it is demanded in the GITEWS (German Indonesian Tsunami Early Warning System) project in which the present work is embedded, this approach is not practicable because a lot of tsunami sources can cause an impact at the coast and must be considered. Thus a multi-scenario tsunami model approach is developed to provide a reliable hazard assessment covering large areas. For the Indonesian Early Warning System many tsunami scenarios were modelled by the Alfred Wegener Institute (AWI) at different probable tsunami sources and with different magnitudes along the Sunda Trench. Every modelled scenario delivers the spatial distribution of the inundation for a specific area, the wave height at coast at this area and the estimated times of arrival (ETAs) of the waves, caused by one tsunamigenic source with a specific magnitude. These parameters from the several scenarios can overlap each other along the coast and must be combined to get one comprehensive hazard assessment for all possible future tsunamis at the region under observation. The simplest way to derive the inundation probability along the coast using the multiscenario approach is to overlay all scenario inundation results and to determine how often a point on land will be significantly inundated from the various scenarios. But this does not take into account that the used tsunamigenic sources for the modeled scenarios have different likelihoods of causing a tsunami. Hence a statistical analysis of historical data and geophysical investigation results based on numerical modelling results is added to the hazard assessment, which clearly improves the significance of the hazard assessment. For this purpose the present method is developed and contains a complex logical combination of the diverse probabilities assessed like probability of occurrence for different earthquake magnitudes at different localities, probability of occurrence for a specific wave height at the coast and the probability for every point on land likely to get hit by a tsunami. The values are combined by a logical tree technique and quantified by statistical analysis of historical data and of the tsunami modelling results as mentioned before. This results in a tsunami inundation probability map covering the South West Coast of Indonesia which nevertheless shows a significant spatial diversity offering a good base for evacuation planning and mitigation strategies. Keywords: tsunami hazard assessment, tsunami modelling, probabilistic analysis, early warning

Risk mapping and tsunami mitigation in Gunungkidul area, Yogyakarta

NASA Astrophysics Data System (ADS)

Mardiatno, Djati; Sunarto, WF, Lies Rahayu; Saptadi, Gatot; Ayuningtyas, Efrinda Ari

2015-04-01

Coastal area of Gunungkidul Regency is one of the areas prone to tsunami in Indonesia. In contrary, currently, this area is very intensively developed as one of the favourite tourism destination. This paper is aimed at explaining tsunami risk and a mitigation type in Gunungkidul Area, Yogyakarta. Digital elevation model (DEM) and coastal morphology were used to generate tsunami hazard map. Vulnerability was analysed by utilizing land use data. Information from previous studies (e.g. from GTZ) were also considered for analysis. Tsunami risk was classified into three classes, i.e. high risk, medium risk, and low risk and visualized in the form of tsunami risk map. Tsunami risk map is a tool which can be used as disaster reduction instrument, such as for evacuation routes planning. Based on the preliminary results of this research, it is clear that tsunami risk in this area is varied depend on the morphological condition of the location. There are five coastal area selected as the location, i.e. Ngrenehan, Baron, Sepanjang, PulangSawal, and Sadeng. All locations have the high risk zone to tsunami, especially for bay area. Evacuation routes were generated for all locations by considering the local landscape condition. There are several differences of evacuation ways for each location.

The Limit of Inundation of the September 29, 2009, Tsunami on Tutuila, American Samoa

USGS Publications Warehouse

Jaffe, Bruce E.; Gelfenbaum, Guy; Buckley, Mark L.; Watt, Steve; Apotsos, Alex; Stevens, Andrew W.; Richmond, Bruce M.

2010-01-01

U.S. Geological Survey scientists investigated the coastal impacts of the September 29, 2009, South Pacific tsunami in Tutuila, American Samoa in October and November 2009, including mapping the alongshore variation in the limit of inundation. Knowing the inundation limit is useful for planning safer coastal development and evacuation routes for future tsunamis and for improving models of tsunami hazards. This report presents field data documenting the limit of inundation at 18 sites around Tutuila collected in the weeks following the tsunami using Differential GPS (DGPS). In total, 15,703 points along inundation lines were mapped. Estimates of DGPS error and uncertainty in interpretation of the inundation line are provided as electronic files that accompany this report.

L'aléa tsunami en Polynésie française : apports de la simulation numérique

NASA Astrophysics Data System (ADS)

Sladen, Anthony; Hébert, Hélène; Schindelé, François; Reymond, Dominique

2007-04-01

French Polynesia is frequently struck by transoceanic tsunamis originating from around the Pacific. The numerical modelling of five scenarios defined among threatening source areas has been performed on seven Polynesian sites. The results show that the Marquesian bays are consistently most affected, while the sites in Tahiti and Rurutu are significantly exposed, though less heavily. The tsunami hazard has been then mapped for whole Polynesia. Major tsunamis are expected to hit Marquesas, and Rurutu (Australes), but less frequently. An elevated hazard level is defined for the other Australes and for several Society Islands (especially Tahiti). Tuamotu atolls and other Society Islands are only moderately exposed.

Probabilistic TSUnami Hazard MAPS for the NEAM Region: The TSUMAPS-NEAM Project

NASA Astrophysics Data System (ADS)

Basili, R.; Babeyko, A. Y.; Baptista, M. A.; Ben Abdallah, S.; Canals, M.; El Mouraouah, A.; Harbitz, C. B.; Ibenbrahim, A.; Lastras, G.; Lorito, S.; Løvholt, F.; Matias, L. M.; Omira, R.; Papadopoulos, G. A.; Pekcan, O.; Nmiri, A.; Selva, J.; Yalciner, A. C.

2016-12-01

As global awareness of tsunami hazard and risk grows, the North-East Atlantic, the Mediterranean, and connected Seas (NEAM) region still lacks a thorough probabilistic tsunami hazard assessment. The TSUMAPS-NEAM project aims to fill this gap in the NEAM region by 1) producing the first region-wide long-term homogenous Probabilistic Tsunami Hazard Assessment (PTHA) from earthquake sources, and by 2) triggering a common tsunami risk management strategy. The specific objectives of the project are tackled by the following four consecutive actions: 1) Conduct a state-of-the-art, standardized, and updatable PTHA with full uncertainty treatment; 2) Review the entire process with international experts; 3) Produce the PTHA database, with documentation of the entire hazard assessment process; and 4) Publicize the results through an awareness raising and education phase, and a capacity building phase. This presentation will illustrate the project layout, summarize its current status of advancement and prospective results, and outline its connections with similar initiatives in the international context. The TSUMAPS-NEAM Project (http://www.tsumaps-neam.eu/) is co-financed by the European Union Civil Protection Mechanism, Agreement Number: ECHO/SUB/2015/718568/PREV26.

Probabilistic TSUnami Hazard MAPS for the NEAM Region: The TSUMAPS-NEAM Project

NASA Astrophysics Data System (ADS)

Basili, Roberto; Babeyko, Andrey Y.; Hoechner, Andreas; Baptista, Maria Ana; Ben Abdallah, Samir; Canals, Miquel; El Mouraouah, Azelarab; Bonnevie Harbitz, Carl; Ibenbrahim, Aomar; Lastras, Galderic; Lorito, Stefano; Løvholt, Finn; Matias, Luis Manuel; Omira, Rachid; Papadopoulos, Gerassimos A.; Pekcan, Onur; Nmiri, Abdelwaheb; Selva, Jacopo; Yalciner, Ahmet C.; Thio, Hong K.

2017-04-01

As global awareness of tsunami hazard and risk grows, the North-East Atlantic, the Mediterranean, and connected Seas (NEAM) region still lacks a thorough probabilistic tsunami hazard assessment. The TSUMAPS-NEAM project aims to fill this gap in the NEAM region by 1) producing the first region-wide long-term homogenous Probabilistic Tsunami Hazard Assessment (PTHA) from earthquake sources, and by 2) triggering a common tsunami risk management strategy. The specific objectives of the project are tackled by the following four consecutive actions: 1) Conduct a state-of-the-art, standardized, and updatable PTHA with full uncertainty treatment; 2) Review the entire process with international experts; 3) Produce the PTHA database, with documentation of the entire hazard assessment process; and 4) Publicize the results through an awareness raising and education phase, and a capacity building phase. This presentation will illustrate the project layout, summarize its current status of advancement including the firs preliminary release of the assessment, and outline its connections with similar initiatives in the international context. The TSUMAPS-NEAM Project (http://www.tsumaps-neam.eu/) is co-financed by the European Union Civil Protection Mechanism, Agreement Number: ECHO/SUB/2015/718568/PREV26.

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.

Multi-Hazard Vulnerability Assessment Along the Coast of Visakhapatnam, North-East Coast of India

NASA Astrophysics Data System (ADS)

Vivek, G.; Grinivasa Kumar, T.

2016-08-01

The current study area is coastal zone of Visakhapatnam, district of Andhra Pradesh along the coast of India. This area is mostly vulnerable to many disasters such as storms, cyclone, flood, tsunami and erosion. This area is considered as cyclone prone area because of frequently occurrence of the cyclones in this area. Recently the two tropical cyclones that formed in the Bay of Bengal are Hudhud (October 13, 2014) and Phylin (October 11, 2013), has caused devastating impacts on the eastern coast and shows that the country has lack of preparedness to cyclone, storm surge and related natural hazards. The multi-hazard vulnerability maps prepared here are a blended and combined overlay of multiple hazards those affecting the coastal zone. The present study aims to develop a methodology for coastal multi-hazard vulnerability assessment. This study carried out using parameters like probability of coastal slope, tsunami arrival height, future sea level rise, coastal erosion and tidal range. The multi-hazard vulnerability maps prepared by overlaying of multi hazards those affecting the coastal zone. Multi-hazard vulnerability maps further reproduced as risk maps with the land use information. The decision making tools presented here can provide a useful information during the disaster for the evacuation process and to evolve a management strategy.

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.

Tsunami hazard, vulnerability and impact assessment of the coastal area of Rabat, Morocco

NASA Astrophysics Data System (ADS)

Lesne, Olivia; Mangin, Antoine; Renou, Camille; Rouffi, Frédéric; Atillah, Abderrahman; Moudni, Hicham

2010-05-01

Among African countries, Morocco is probably one of the most exposed to tsunami hazard. Indeed, Morocco is integrated in the particular geodynamic context of the northern African margin characterized by the existence of the Azores-Gibraltar fault separating two active tectonic plates: the African and the Eurasian plates. This area generated and still generates many large earthquakes exceeding a magnitude of 6. The Moroccan Atlantic coasts are thus exposed to tsunamigenic earthquakes occurring offshore. Tsunamis generated in this area are not frequent but can be really disastrous and could have a huge impact. In the framework of the SCHEMA project, a 3 year European project, we studied the consequences on the Moroccan coastal area of two potential tsunami scenarios, applying the generic methodology developed during the project for building tsunami vulnerability and impact maps. The study focuses on the "Rabat Zaïr" region. Centred on the Bouregreg Valley, this study area encompasses three main coastal and densely populated towns of Morocco: Rabat (capital), Salé and Temara. Using a combination of numerical modelling, field surveys, earth observation and GIS data, the risk has been evaluated for this highly vulnerable area (flat topography, small beaches with many tourists in summer, presence of several bridges on the Bouregreg river separating Rabat and Salé, presence of a dam upstream the 2 cities, and development of a new residential and touristic complex on the coastline and in the vicinity of the estuary). Two scenarios of tsunami have been studied to estimate the hazard on the coastal zone of Rabat: a worst case scenario based on the historical Lisbon earthquake of 1755 as well as a moderate scenario based on the historical Portugal earthquake of 1969. For each scenario, numerical models allowed to produce inundation maps consisting of inundation limits as well as maximum water heights. Land use data together with earth observation data interpretation allowed then to generate a building classification. Finally potential damages are derived using damage functions developed during the project by Geosciences Consultants (GSC), by crossing information from hazard maps (maximum water elevations) with building vulnerability maps. The damage maps will then serve as a base for elaborating evacuation plans with appropriate rescue and relief processes useful for decision makers, local authorities and investors.

New seafloor map of the Puerto Rico trench helps assess earthquake and tsunami hazards

NASA Astrophysics Data System (ADS)

Brink, Uri ten; Danforth, William; Polloni, Christopher; Andrews, Brian; Llanes, Pilar; Smith, Shepard; Parker, Eugene; Uozumi, Toshihiko

2004-09-01

The Puerto Rico Trench, the deepest part of the Atlantic Ocean, is located where the North American (NOAM) plate is subducting under the Caribbean plate (Figure l). The trench region may pose significant seismic and tsunami hazards to Puerto Rico and the U.S.Virgin Islands, where 4 million U.S. citizens reside. Widespread damage in Puerto Rico and Hispaniola from an earthquake in 1787 was estimated to be the result of a magnitude 8 earthquake north of the islands [McCann et al., 2004]. A tsunami killed 40 people in NW Puerto Rico following a magnitude 7.3 earthquake in 1918 [Mercado and McCann, 1998]. Large landslide escarpments have been mapped on the seafloor north of Puerto Rico [Mercado et al., 2002; Schwab et al., 1991],although their ages are unknown.

New seafloor map of the Puerto Rico Trench helps assess earthquake and tsunami hazards

USGS Publications Warehouse

ten Brink, Uri S.; Danforth, William; Polloni, Christopher; Andrews, Brian D.; Llanes Estrada, Pilar; Smith, Shepard; Parker, Eugene; Uozumi, Toshihiko

2004-01-01

The Puerto Rico Trench, the deepest part of the Atlantic Ocean, is located where the North American (NOAM) plate is subducting under the Caribbean plate (Figure l). The trench region may pose significant seismic and tsunami hazards to Puerto Rico and the U.S.Virgin Islands, where 4 million U.S. citizens reside. Widespread damage in Puerto Rico and Hispaniola from an earthquake in 1787 was estimated to be the result of a magnitude 8 earthquake north of the islands [McCann et al., 2004]. A tsunami killed 40 people in NW Puerto Rico following a magnitude 7.3 earthquake in 1918 [Mercado and McCann, 1998]. Large landslide escarpments have been mapped on the seafloor north of Puerto Rico [Mercado et al., 2002; Schwab et al., 1991],although their ages are unknown.

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.

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).

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.

The exposure of Sydney (Australia) to earthquake-generated tsunamis, storms and sea level rise: a probabilistic multi-hazard approach

PubMed Central

Dall'Osso, F.; Dominey-Howes, D.; Moore, C.; Summerhayes, S.; Withycombe, G.

2014-01-01

Approximately 85% of Australia's population live along the coastal fringe, an area with high exposure to extreme inundations such as tsunamis. However, to date, no Probabilistic Tsunami Hazard Assessments (PTHA) that include inundation have been published for Australia. This limits the development of appropriate risk reduction measures by decision and policy makers. We describe our PTHA undertaken for the Sydney metropolitan area. Using the NOAA NCTR model MOST (Method for Splitting Tsunamis), we simulate 36 earthquake-generated tsunamis with annual probabilities of 1:100, 1:1,000 and 1:10,000, occurring under present and future predicted sea level conditions. For each tsunami scenario we generate a high-resolution inundation map of the maximum water level and flow velocity, and we calculate the exposure of buildings and critical infrastructure. Results indicate that exposure to earthquake-generated tsunamis is relatively low for present events, but increases significantly with higher sea level conditions. The probabilistic approach allowed us to undertake a comparison with an existing storm surge hazard assessment. Interestingly, the exposure to all the simulated tsunamis is significantly lower than that for the 1:100 storm surge scenarios, under the same initial sea level conditions. The results have significant implications for multi-risk and emergency management in Sydney. PMID:25492514

The exposure of Sydney (Australia) to earthquake-generated tsunamis, storms and sea level rise: a probabilistic multi-hazard approach.

PubMed

Dall'Osso, F; Dominey-Howes, D; Moore, C; Summerhayes, S; Withycombe, G

2014-12-10

Approximately 85% of Australia's population live along the coastal fringe, an area with high exposure to extreme inundations such as tsunamis. However, to date, no Probabilistic Tsunami Hazard Assessments (PTHA) that include inundation have been published for Australia. This limits the development of appropriate risk reduction measures by decision and policy makers. We describe our PTHA undertaken for the Sydney metropolitan area. Using the NOAA NCTR model MOST (Method for Splitting Tsunamis), we simulate 36 earthquake-generated tsunamis with annual probabilities of 1:100, 1:1,000 and 1:10,000, occurring under present and future predicted sea level conditions. For each tsunami scenario we generate a high-resolution inundation map of the maximum water level and flow velocity, and we calculate the exposure of buildings and critical infrastructure. Results indicate that exposure to earthquake-generated tsunamis is relatively low for present events, but increases significantly with higher sea level conditions. The probabilistic approach allowed us to undertake a comparison with an existing storm surge hazard assessment. Interestingly, the exposure to all the simulated tsunamis is significantly lower than that for the 1:100 storm surge scenarios, under the same initial sea level conditions. The results have significant implications for multi-risk and emergency management in Sydney.

Quantification of tsunami hazard on Canada's Pacific Coast; implications for risk assessment

NASA Astrophysics Data System (ADS)

Evans, Stephen G.; Delaney, Keith B.

2015-04-01

Our assessment of tsunami hazard on Canada's Pacific Coast (i.e., the coast of British Columbia) begins with a review of the 1964 tsunami generated by The Great Alaska Earthquake (M9.2) that resulted in significant damage to coastal communities and infrastructure. In particular, the tsunami waves swept up inlets on the west coast of Vancouver Island and damaged several communities; Port Alberni suffered upwards of 5M worth of damage. At Port Alberni, the maximum tsunami wave height was estimated at 8.2 m above mean sea level and was recorded on the stream gauge on the Somass River located at about 7 m a.s.l, 6 km upstream from its mouth. The highest wave (9.75 m above tidal datum) was reported from Shields Bay, Graham Island, Queen Charlotte Islands (Haida Gwaii). In addition, the 1964 tsunami was recorded on tide gauges at a number of locations on the BC coast. The 1964 signal and the magnitude and frequency of traces of other historical Pacific tsunamis (both far-field and local) are analysed in the Tofino tide gauge records and compared to tsunami traces in other tide gauges in the Pacific Basin (e.g., Miyako, Japan). Together with a review of the geological evidence for tsunami occurrence along Vancouver Island's west coast, we use this tide gauge data to develop a quantitative framework for tsunami hazard on Canada's Pacific coast. In larger time scales, tsunamis are a major component of the hazard from Cascadia megathrust events. From sedimentological evidence and seismological considerations, the recurrence interval of megathrust events on the Cascadia Subduction Zone has been estimated by others at roughly 500 years. We assume that the hazard associated with a high-magnitude destructive tsunami thus has an annual frequency of roughly 1/500. Compared to other major natural hazards in western Canada this represents a very high annual probability of potentially destructive hazard that, in some coastal communities, translates into high levels of local risk including life-loss risk. Our analysis further indicates that in terms of life-loss risk, communities on Canada's Pacific Coast that are exposed to high tsunami hazard, experience the highest natural risk in Canada. Although sparsely populated, the (outer) coast of British Columbia has important critical infrastructure that includes port developments, shoreline facilities related to forest resource exploitation, a large number of First Nations Reserves, small municipal centres, towns, and villages, (some of which are ecotourism and sport fishing centres), and a limited number of industrial facilities. For selected areas on the west coast of Vancouver Island inundation maps have been prepared for a range of tsunami scenarios. We find that key facilities and critical infrastructure are exposed to the hazards associated with tsunami inundation.

Tsunami Loss Assessment For Istanbul

NASA Astrophysics Data System (ADS)

Hancilar, Ufuk; Cakti, Eser; Zulfikar, Can; Demircioglu, Mine; Erdik, Mustafa

2010-05-01

Tsunami risk and loss assessment incorporating with the inundation mapping in Istanbul and the Marmara Sea region are presented in this study. The city of Istanbul is under the threat of earthquakes expected to originate from the Main Marmara branch of North Anatolian Fault System. In the Marmara region the earthquake hazard reached very high levels with 2% annual probability of occurrence of a magnitude 7+ earthquake on the Main Marmara Fault. Istanbul is the biggest city of Marmara region as well as of Turkey with its almost 12 million inhabitants. It is home to 40% of the industrial facilities in Turkey and operates as the financial and trade hub of the country. Past earthquakes have evidenced that the structural reliability of residential and industrial buildings, as well as that of lifelines including port and harbor structures in the country is questionable. These facts make the management of earthquake risks imperative for the reduction of physical and socio-economic losses. The level of expected tsunami hazard in Istanbul is low as compared to earthquake hazard. Yet the assets at risk along the shores of the city make a thorough assessment of tsunami risk imperative. Important residential and industrial centres exist along the shores of the Marmara Sea. Particularly along the northern and eastern shores we see an uninterrupted settlement pattern with industries, businesses, commercial centres and ports and harbours in between. Following the inundation maps resulting from deterministic and probabilistic tsunami hazard analyses, vulnerability and risk analyses are presented and the socio-economic losses are estimated. This study is part of EU-supported FP6 project ‘TRANSFER'.

Probabilistic tsunami inundation map based on stochastic earthquake source model: A demonstration case in Macau, the South China Sea

NASA Astrophysics Data System (ADS)

Li, Linlin; Switzer, Adam D.; Wang, Yu; Chan, Chung-Han; Qiu, Qiang; Weiss, Robert

2017-04-01

Current tsunami inundation maps are commonly generated using deterministic scenarios, either for real-time forecasting or based on hypothetical "worst-case" events. Such maps are mainly used for emergency response and evacuation planning and do not include the information of return period. However, in practice, probabilistic tsunami inundation maps are required in a wide variety of applications, such as land-use planning, engineer design and for insurance purposes. In this study, we present a method to develop the probabilistic tsunami inundation map using a stochastic earthquake source model. To demonstrate the methodology, we take Macau a coastal city in the South China Sea as an example. Two major advances of this method are: it incorporates the most updated information of seismic tsunamigenic sources along the Manila megathrust; it integrates a stochastic source model into a Monte Carlo-type simulation in which a broad range of slip distribution patterns are generated for large numbers of synthetic earthquake events. When aggregated the large amount of inundation simulation results, we analyze the uncertainties associated with variability of earthquake rupture location and slip distribution. We also explore how tsunami hazard evolves in Macau in the context of sea level rise. Our results suggest Macau faces moderate tsunami risk due to its low-lying elevation, extensive land reclamation, high coastal population and major infrastructure density. Macau consists of four districts: Macau Peninsula, Taipa Island, Coloane island and Cotai strip. Of these Macau Peninsula is the most vulnerable to tsunami due to its low-elevation and exposure to direct waves and refracted waves from the offshore region and reflected waves from mainland. Earthquakes with magnitude larger than Mw8.0 in the northern Manila trench would likely cause hazardous inundation in Macau. Using a stochastic source model, we are able to derive a spread of potential tsunami impacts for earthquakes with the same magnitude. The diversity is caused by both random rupture locations and heterogeneous slip distribution. Adding the sea level rise component, the inundated depth caused by 1 m sea level rise is equivalent to the one caused by 90 percentile of an ensemble of Mw8.4 earthquakes.

Site-specific seismic probabilistic tsunami hazard analysis: performances and potential applications

NASA Astrophysics Data System (ADS)

Tonini, Roberto; Volpe, Manuela; Lorito, Stefano; Selva, Jacopo; Orefice, Simone; Graziani, Laura; Brizuela, Beatriz; Smedile, Alessandra; Romano, Fabrizio; De Martini, Paolo Marco; Maramai, Alessandra; Piatanesi, Alessio; Pantosti, Daniela

2017-04-01

Seismic Probabilistic Tsunami Hazard Analysis (SPTHA) provides probabilities to exceed different thresholds of tsunami hazard intensity, at a specific site or region and in a given time span, for tsunamis caused by seismic sources. Results obtained by SPTHA (i.e., probabilistic hazard curves and inundation maps) represent a very important input to risk analyses and land use planning. However, the large variability of source parameters implies the definition of a huge number of potential tsunami scenarios, whose omission could lead to a biased analysis. Moreover, tsunami propagation from source to target requires the use of very expensive numerical simulations. At regional scale, the computational cost can be reduced using assumptions on the tsunami modeling (i.e., neglecting non-linear effects, using coarse topo-bathymetric meshes, empirically extrapolating maximum wave heights on the coast). On the other hand, moving to local scale, a much higher resolution is required and such assumptions drop out, since detailed inundation maps require significantly greater computational resources. In this work we apply a multi-step method to perform a site-specific SPTHA which can be summarized in the following steps: i) to perform a regional hazard assessment to account for both the aleatory and epistemic uncertainties of the seismic source, by combining the use of an event tree and an ensemble modeling technique; ii) to apply a filtering procedure which use a cluster analysis to define a significantly reduced number of representative scenarios contributing to the hazard of a specific target site; iii) to perform high resolution numerical simulations only for these representative scenarios and for a subset of near field sources placed in very shallow waters and/or whose coseismic displacements induce ground uplift or subsidence at the target. The method is applied to three target areas in the Mediterranean located around the cities of Milazzo (Italy), Thessaloniki (Greece) and Siracusa (Italy). The latter target analysis is enriched by the use of local observed tsunami data, both geological and historical. Indeed, tsunami data-sets available for Siracusa are particularly rich with respect to the scarce and heterogeneous data-sets usually available elsewhere. Therefore, they can represent a further valuable source of information to benchmark and strengthen the results of such kind of studies. The work is funded by the Italian Flagship Project RITMARE, the two EC FP7 ASTARTE (Grant agreement 603839) and STREST (Grant agreement 603389) projects, the TSUMAPS-NEAM (Grant agreement ECHO/SUB/2015/718568/PREV26) project and the INGV-DPC Agreement.

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.

Assessing natural hazard risk using images and data

NASA Astrophysics Data System (ADS)

Mccullough, H. L.; Dunbar, P. K.; Varner, J. D.; Mungov, G.

2012-12-01

Photographs and other visual media provide valuable pre- and post-event data for natural hazard assessment. Scientific research, mitigation, and forecasting rely on visual data for risk analysis, inundation mapping and historic records. Instrumental data only reveal a portion of the whole story; photographs explicitly illustrate the physical and societal impacts from the event. Visual data is rapidly increasing as the availability of portable high resolution cameras and video recorders becomes more attainable. Incorporating these data into archives ensures a more complete historical account of events. Integrating natural hazards data, such as tsunami, earthquake and volcanic eruption events, socio-economic information, and tsunami deposits and runups along with images and photographs enhances event comprehension. Global historic databases at NOAA's National Geophysical Data Center (NGDC) consolidate these data, providing the user with easy access to a network of information. NGDC's Natural Hazards Image Database (ngdc.noaa.gov/hazardimages) was recently improved to provide a more efficient and dynamic user interface. It uses the Google Maps API and Keyhole Markup Language (KML) to provide geographic context to the images and events. Descriptive tags, or keywords, have been applied to each image, enabling easier navigation and discovery. In addition, the Natural Hazards Map Viewer (maps.ngdc.noaa.gov/viewers/hazards) provides the ability to search and browse data layers on a Mercator-projection globe with a variety of map backgrounds. This combination of features creates a simple and effective way to enhance our understanding of hazard events and risks using imagery.

Tsunami Hazard, Vulnerability and Risk assessment for the coast of Oman

NASA Astrophysics Data System (ADS)

Gonzalez, Mauricio; Aniel-Quiroga, Íñigo; Aguirre-Ayerbe, Ignacio; Álvarez-Gómez, José Antonio; MArtínez, Jara; Gonzalez-Riancho, Pino; Fernandez, Felipe; Medina, Raúl; Al-Yahyai, Sultan

2016-04-01

Tsunamis are relatively infrequent phenomena representing a greater threat than earthquakes, hurricanes and tornadoes, and causing the loss of thousands of human lives and extensive damage to coastal infrastructures around the world. Advances in the understanding and prediction of tsunami impacts allow the development of new methodologies in this field. This work presents the methodology that has been followed for developing the tsunami hazard, vulnerability and risk assessment for the coast of Oman, including maps containing the results of the process. Oman is located in the south eastern corner of the Arabian Peninsula and of the Arabian plate, in front of the Makran Subduction Zone (MSZ), which is the major source of earthquakes in the eastern border of the Arabian plate and Oman (Al-Shaqsi, 2012). There are at least three historical tsunamis assigned to seismic origin in the MSZ (Heidarzadeh et al., 2008; Jordan, 2008). These events show the high potential for tsunami generation of the MSZ, being one of the most tsunamigenic zones in the Indian Ocean. For the tsunami hazard assessment, worst potential cases have been selected, as well as the historical case of 1945, when an 8.1 earthquake generated a tsunami affecting the coast of Oman, and prompting 4000 casualties in the countries of the area. These scenarios have been computationally simulated in order to get tsunami hazard maps, including flooding maps. These calculations have been carried out at national and local scale, in 9 municipalities all along the coast of Oman, including the cities of Sohar, Wudam, Sawadi, Muscat, Quriyat, Sur, Masirah, Al Duqm, and Salalah. Using the hazard assessment as input, this work presents as well an integrated framework for the tsunami vulnerability and risk assessment carried out in the Sultanate of Oman. This framework considers different dimensions (human, structural) and it is developed at two different spatial resolutions, national and local scale. The national vulnerability assessment is carried out for the entire Oman coastal area comprising 30 coastal wilayats, whereas the local sensitivity assessment is performed for the 9 coastal study areas. This work also connects vulnerability-risk assessment results to site-specific and target-oriented risk reduction measures. Results identify high risk areas along the coast of Oman in which measures for risk reduction are proposed. The identification and prioritization of mitigation measures were supported by a panel of local and international experts developed during a Risk Assessment Workshop held in Oman and a handbook containing the mitigation measures at national and local scales was developed and delivered to the stakeholders. We would like to thank the Ministry of Transport and Communications of the Government of the Sultanate of Oman (MOTC), Directorate General of Meteorology and Air Navigation (DGMAN), Public Authority for Civil Aviation (PACA), for supporting and funding this project and the collaboration of the IOC-UNESCO personnel. The research leading to these results has received funding from the European Union's Seventh Framework Programme (FP7/2007-2013) under grant agreement n° 603839 (Project ASTARTE - Assessment, Strategy and Risk Reduction for Tsunamis in Europe).

Validation of NEOWAVE with Measurements from the 2011 Tohoku Tsunami

NASA Astrophysics Data System (ADS)

Cheung, K.; Yamazaki, Y.

2012-12-01

An accurate and reliable numerical model is essential in mapping tsunami hazards for mitigation and preparedness. The model NEOWAVE (Non-hydrostatic Evolution of Ocean WAVEs) is being used for tsunami inundation mapping in Hawaii, American Samoa, the Gulf coast states, and Puerto Rico. In addition to the benchmarks established by the National Tsunami Hazard Mitigation Program, we have been conducting a thorough investigation of NEOWAVE's capability in reproducing the 2011 Tohoku tsunami and its impact across the Pacific. The shock-capturing non-hydrostatic model is well suited to handle tsunami conditions in a variety of coastal environments in the near and far field. It describes dispersive waves through non-hydrostatic pressure and vertical velocity, which also account for tsunami generation from time histories of seafloor deformation. The semi-implicit, staggered finite difference model captures flow discontinuities associated with bores or hydraulic jumps through a momentum conservation scheme. The model supports up to five levels of two-way nested grids in spherical coordinates to describe tsunami processes of varying time and spatial scales from the open ocean to the coast. We first define the source mechanism through forward modeling of the near-field tsunami recorded by coastal and deep-ocean buoys. A finite-fault solution based on teleseismic P-wave inversion serves as the starting point of the iterative process, in which the source parameters are systematically adjusted to achieve convergence of the computed tsunami with the near-field records. The capability of NEOWAVE in modeling propagation of the tsunami is evaluated with DART data across the Pacific as well as water-level and current measurements in Hawaii. These far-field water-level records, which are not considered in the forward modeling, also provide an independently assessment of the source model. The computed runup and inundation are compared with measurements along Northeastern Japan coasts and the Hawaiian Island chain. These coastlines include shallow embayments with open plains, narrow estuaries with steep cliffs, and volcanic insular slopes with fringing reefs for full validation of the model in a single event. The Tohoku tsunami caused persistent oscillations and hazardous currents in coastal waters around Hawaii. Analysis of the computed surface elevation reveals complex resonance modes along the Hawaiian Island chain. Standing waves with period 16 min or shorter are able to form a series of nodes and antinodes over the reefs that results in strong currents and large drawdown responsible for the damage in harbors and marinas. The results provide insights into effects of fringing reefs, which are present along 70% of Hawaii's coastlines, on tsunami transformation and runup processes. The case study improves our understanding on tsunamis in tropical island environments and validates the modeling capability to predict their impacts for hazard mitigation and emergency management.

Geoethical and socio-political aspects of seismic and tsunami hazard assessment, quantification and mapping

NASA Astrophysics Data System (ADS)

Tinti, Stefano; Armigliato, Alberto

2016-04-01

Seismic hazard and, more recently, tsunami hazard assessments have been undertaken in several countries of the world and globally for the whole Earth planet with the aim of providing a scientifically sound basis to the engineers, technicians, urban and industrial planners, politicians, civil protection operators and in general to the authorities for devising rational risk mitigation strategies and corresponding adequate policies. The main point of this presentation is that the chief-value of all seismic and tsunami hazard studies (including theory, concept, quantification and mapping) resides in the social and political values of the provided products, which is a standpoint entailing a number of relevant geoethical implications. The most relevant implication regards geoscientists who are the subjects mainly involved in carrying out hazard evaluations. Viewed from the classical perspective, the main ethical obligations of geoscientists are restricted to performing hazard estimations in the best possible way from a scientific point of view, which means selecting the "best" available data, adopting sound theoretical models, making use of rigorous methods… What is outlined here, is that this is an insufficient minimalistic position, since it overlooks the basic socio-political and therefore practical value of the hazard-analysis final products. In other words, if one views hazard assessment as a production process leading from data and theories (raw data and production means) to hazard maps (products), the criterion to judge whether it is good or bad needs also to include the usability factor. Seismic and tsunami hazard reports and maps are products that should be usable, which means that they should meet user needs and requirements, and therefore they should be evaluated according to how much they are clearly understandable to, and appropriate for, making-decision users. In the traditional view of a science serving the society, one could represent the interaction process as a line connecting geoscientists and users, where geoscientists possess the knowledge (data, theory and models) and teach, while users get products and learn. The new geoethical perspective is that the line is replaced by a loop, where geoscientists and users interact cyclically: 1) where theory and methods themselves are not determined a-priori, but they result also in response of geoscientists-users interactions, and 2) where user needs can be modified ex-post in response to geoscientists elaborations. These two-way feedback actions, opening also the path to close interdisciplinary approaches involving geo- and social sciences, are the main challenge for the present generation of geoscientists. Unfortunately they are not properly and adequately reflected in the today university educational systems, and in professional societies.

Getting out of harm's way - evacuation from tsunamis

USGS Publications Warehouse

Jones, Jeanne M.; Wood, Nathan J.; Gordon, Leslie C.

2015-01-01

Maps of travel time can be used by emergency managers and community planners to identify where to focus evacuation training and tsunami education. The tool can also be used to examine the potential benefits of vertical-evacuation structures, which are buildings or berms designed to provide a local high ground in low-lying areas of the hazard zone. 

Numerical study of tsunami generated by multiple submarine slope failures in Resurrection Bay, Alaska, during the MW 9.2 1964 earthquake

USGS Publications Warehouse

Suleimani, E.; Hansen, R.; Haeussler, Peter J.

2009-01-01

We use a viscous slide model of Jiang and LeBlond (1994) coupled with nonlinear shallow water equations to study tsunami waves in Resurrection Bay, in south-central Alaska. The town of Seward, located at the head of Resurrection Bay, was hit hard by both tectonic and local landslide-generated tsunami waves during the MW 9.2 1964 earthquake with an epicenter located about 150 km northeast of Seward. Recent studies have estimated the total volume of underwater slide material that moved in Resurrection Bay during the earthquake to be about 211 million m3. Resurrection Bay is a glacial fjord with large tidal ranges and sediments accumulating on steep underwater slopes at a high rate. Also, it is located in a seismically active region above the Aleutian megathrust. All these factors make the town vulnerable to locally generated waves produced by underwater slope failures. Therefore it is crucial to assess the tsunami hazard related to local landslide-generated tsunamis in Resurrection Bay in order to conduct comprehensive tsunami inundation mapping at Seward. We use numerical modeling to recreate the landslides and tsunami waves of the 1964 earthquake to test the hypothesis that the local tsunami in Resurrection Bay has been produced by a number of different slope failures. We find that numerical results are in good agreement with the observational data, and the model could be employed to evaluate landslide tsunami hazard in Alaska fjords for the purposes of tsunami hazard mitigation. ?? Birkh??user Verlag, Basel 2009.

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

Numerical Tsunami Hazard Assessment of the Only Active Lesser Antilles Arc Submarine Volcano: Kick 'em Jenny.

NASA Astrophysics Data System (ADS)

Dondin, F. J. Y.; Dorville, J. F. M.; Robertson, R. E. A.

2015-12-01

The Lesser Antilles Volcanic Arc has potentially been hit by prehistorical regional tsunamis generated by voluminous volcanic landslides (volume > 1 km3) among the 53 events recognized so far. No field evidence of these tsunamis are found in the vincity of the sources. Such a scenario taking place nowadays would trigger hazardous tsunami waves bearing potentially catastrophic consequences for the closest islands and regional offshore oil platforms.Here we applied a complete hazard assessment method on the only active submarine volcano of the arc Kick 'em Jenny (KeJ). KeJ is the southernmost edifice with recognized associated volcanic landslide deposits. From the three identified landslide episodes one is associated with a collapse volume ca. 4.4 km3. Numerical simulations considering a single pulse collapse revealed that this episode would have produced a regional tsunami. An edifice current volume estimate is ca. 1.5 km3.Previous study exists in relationship to assessment of regional tsunami hazard related to shoreline surface elevation (run-up) in the case of a potential flank collapse scenario at KeJ. However this assessment was based on inferred volume of collapse material. We aim to firstly quantify potential initial volumes of collapse material using relative slope instability analysis (RSIA); secondly to assess first order run-ups and maximum inland inundation distance for Barbados and Trinidad and Tobago, i.e. two important economic centers of the Lesser Antilles. In this framework we present for seven geomechanical models tested in the RSIA step maps of critical failure surface associated with factor of stability (Fs) for twelve sectors of 30° each; then we introduce maps of expected potential run-ups (run-up × the probability of failure at a sector) at the shoreline.The RSIA evaluates critical potential failure surface associated with Fs <1 as compared to areas of deficit/surplus of mass/volume identified on the volcanic edifice using (VolcanoFit 2.0 & SSAP 4.5). Tsunami sources characteristics are retrieved from numerical simulation using an hydraulic equations-based code (VolcFlow-Matlab). The tsunami propagation towards the coasts is computed using the open source a Boussinesq equations-based code (FUNWAVE) taking into account high order non linear effects including dissipation.

Preliminary tsunami hazard assessment in British Columbia, Canada

NASA Astrophysics Data System (ADS)

Insua, T. L.; Grilli, A. R.; Grilli, S. T.; Shelby, M. R.; Wang, K.; Gao, D.; Cherniawsky, J. Y.; Harris, J. C.; Heesemann, M.; McLean, S.; Moran, K.

2015-12-01

Ocean Networks Canada (ONC), a not-for-profit initiative by the University of Victoria that operates several cabled ocean observatories, is developing a new generation of ocean observing systems (referred to as Smart Ocean Systems™), involving advanced undersea observation technologies, data networks and analytics. The ONC Tsunami project is a Smart Ocean Systems™ project that addresses the need for a near-field tsunami detection system for the coastal areas of British Columbia. Recent studies indicate that there is a 40-80% probability over the next 50 for a significant tsunami impacting the British Columbia (BC) coast with runups higher than 1.5 m. The NEPTUNE cabled ocean observatory, operated by ONC off of the west coast of British Columbia, could be used to detect near-field tsunami events with existing instrumentation, including seismometers and bottom pressure recorders. As part of this project, new tsunami simulations are underway for the BC coast. Tsunami propagation is being simulated with the FUNWAVE-TVD model, for a suite of new source models representing Cascadia megathrust rupture scenarios. Simulations are performed by one-way coupling in a series of nested model grids (from the source to the BC coast), whose bathymetry was developed based on digital elevation maps (DEMs) of the area, to estimate both tsunami arrival time and coastal runup/inundation for different locations. Besides inundation, maps of additional parameters such as maximum current are being developed, that will aid in tsunami hazard assessment and risk mitigation, as well as developing evacuation plans. We will present initial results of this work for the Port Alberni inlet, in particular Ucluelet, based on new source models developed using the best available data. We will also present a model validation using measurements of the 2011 transpacific Tohoku-oki tsunami recorded in coastal BC by several instruments from various US and Canadian agencies.

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.

Pedestrian flow-path modeling to support tsunami-evacuation planning

NASA Astrophysics Data System (ADS)

Wood, N. J.; Jones, J. M.; Schmidtlein, M.

2015-12-01

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 potentially arriving in a matter of minutes following a Cascadia subduction zone (CSZ) earthquake. We developed a geospatial-modeling method for characterizing pedestrian-evacuation flow paths and evacuation basins to support evacuation and relief planning efforts for coastal communities in this region. We demonstrate this approach using the coastal communities of Aberdeen, Hoquiam, and Cosmopolis in southwestern Grays Harbor County, Washington (USA), where previous research suggests approximately 20,500 people (99% of the residents in tsunami-hazard zones) will likely have enough time to evacuate before tsunami-wave arrival. Geospatial, anisotropic, path distance models were developed to map the most efficient pedestrian paths to higher ground from locations within the tsunami-hazard zone. This information was then used to identify evacuation basins, outlining neighborhoods sharing a common evacuation pathway to safety. We then estimated the number of people traveling along designated evacuation pathways and arriving at pre-determined safe assembly areas, helping determine shelter demand and relief support (e.g., for elderly individuals or tourists). Finally, we assessed which paths may become inaccessible due to earthquake-induced ground failures, a factor which may impact an individual's success in reaching safe ground. The presentation will include a discussion of the implications of our analysis for developing more comprehensive coastal community tsunami-evacuation planning strategies worldwide.

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.

Source mechanisms of volcanic tsunamis.

PubMed

Paris, Raphaël

2015-10-28

Volcanic tsunamis are generated by a variety of mechanisms, including volcano-tectonic earthquakes, slope instabilities, pyroclastic flows, underwater explosions, shock waves and caldera collapse. In this review, we focus on the lessons that can be learnt from past events and address the influence of parameters such as volume flux of mass flows, explosion energy or duration of caldera collapse on tsunami generation. The diversity of waves in terms of amplitude, period, form, dispersion, etc. poses difficulties for integration and harmonization of sources to be used for numerical models and probabilistic tsunami hazard maps. In many cases, monitoring and warning of volcanic tsunamis remain challenging (further technical and scientific developments being necessary) and must be coupled with policies of population preparedness. © 2015 The Author(s).

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.

Earthquake and tsunami hazard in West Sumatra: integrating science, outreach, and local stakeholder needs

NASA Astrophysics Data System (ADS)

McCaughey, J.; Lubis, A. M.; Huang, Z.; Yao, Y.; Hill, E. M.; Eriksson, S.; Sieh, K.

2012-04-01

The Earth Observatory of Singapore (EOS) is building partnerships with local to provincial government agencies, NGOs, and educators in West Sumatra to inform their policymaking, disaster-risk-reduction, and education efforts. Geodetic and paleoseismic studies show that an earthquake as large as M 8.8 is likely sometime in the coming decades on the Mentawai patch of the Sunda megathrust. This earthquake and its tsunami would be devastating for the Mentawai Islands and neighboring areas of the western Sumatra coast. The low-lying coastal Sumatran city of Padang (pop. ~800,000) has been the object of many research and outreach efforts, especially since 2004. Padang experienced deadly earthquakes in 2007 and 2009 that, though tragedies in their own right, served also as wake-up calls for a larger earthquake to come. However, there remain significant barriers to linking science to policy: extant hazard information is sometimes contradictory or confusing for non-scientists, while turnover of agency leadership and staff means that, in the words of one local advocate, "we keep having to start from zero." Both better hazard knowledge and major infrastructure changes are necessary for risk reduction in Padang. In contrast, the small, isolated villages on the outlying Mentawai Islands have received relatively fewer outreach efforts, yet many villages have the potential for timely evacuation with existing infrastructure. Therefore, knowledge alone can go far toward risk reduction. The tragic October 2010 Mentawai tsunami has inspired further disaster-risk reduction work by local stakeholders. In both locations, we are engaging policymakers and local NGOs, providing science to help inform their work. Through outreach contacts, the Mentawai government requested that we produce the first-ever tsunami hazard map for their islands; this aligns well with scientific interests at EOS. We will work with the Mentawai government on the presentation and explanation of the hazard map, as well as assessment of its impact at the district and village levels. We are also providing science and teaching examples for an NGO-led program to integrate disaster-risk reduction into the Mentawai primary-school curriculum. We are working with our partners to develop a participatory monitoring scheme. Indicators will include the degree to which policy is informed by science, whether communities develop and publicise evacuation routes based on hazard mapping, whether and how frequently communities practice evacuation simulations, and whether hazard information is incorporated into school curricula.

Tsunami Evacuation Plan for the City of Tangier-Morocco

NASA Astrophysics Data System (ADS)

Benchekroun, Sabah; Omira, Rachid; Baptista, Maria Ana; Arbi Toto, El

2016-04-01

Tsunami evacuation plan is an important tool to mitigate the tsunami impact. It is the most efficient way to save human lives, well before the waves reach the threatened coastal area, by providing evacuation routes and appropriate shelters. In this study, we propose a tsunami evacuation plan for the city of Tangier-Morocco. This plan is designed considering the tsunami threat from the tsunamigenic sources located in the SW Iberia Margin and using the inundation maps of the worst case to define the limit of flooding area. The evacuation plan is elaborated through modelling the required time for the threatened coastal population to reach the shelters. Results of this study will be useful for decision makers and local authorities in preventing the community resiliency for tsunami hazard. This work received funding from collaborative project ASTARTE - Assessment Strategy and Risk Reduction for Tsunamis in Europe Grant 603839, FP7.

Specification of Tectonic Tsunami Sources Along the Eastern Aleutian Island Arc and Alaska Peninsula for Inundation Mapping and Hazard Assessment

NASA Astrophysics Data System (ADS)

Suleimani, E.; Nicolsky, D.; Freymueller, J. T.; Koehler, R.

2013-12-01

The Alaska Earthquake Information Center conducts tsunami inundation mapping for coastal communities in Alaska along several segments of the Aleutian Megathrust, each having a unique seismic history and tsunami generation potential. Accurate identification and characterization of potential tsunami sources is a critical component of our project. As demonstrated by the 2011 Tohoku-oki tsunami, correct estimation of the maximum size event for a given segment of the subduction zone is particularly important. In that event, unexpectedly large slip occurred approximately updip of the epicenter of the main shock, based on seafloor GPS and seafloor pressure gage observations, generating a much larger tsunami than anticipated. This emphasizes the importance of the detailed knowledge of the region-specific subduction processes, and using the most up-to-date geophysical data and research models that define the magnitude range of possible future tsunami events. Our study area extends from the eastern half of the 1957 rupture zone to Kodiak Island, covering the 1946 and 1938 rupture areas, the Shumagin gap, and the western part of the 1964 rupture area. We propose a strategy for generating worst-case credible tsunami scenarios for locations that have a short or nonexistent paleoseismic/paleotsunami record, and in some cases lack modern seismic and GPS data. The potential tsunami scenarios are built based on a discretized plate interface model fit to the Slab 1.0 model geometry. We employ estimates of slip deficit along the Aleutian Megathrust from GPS campaign surveys, the Slab 1.0 interface surface, empirical magnitude-slip relationships, and a numerical code that distributes slip among the subfault elements, calculates coseismic deformations and solves the shallow water equations of tsunami propagation and runup. We define hypothetical asperities along the megathrust and in down-dip direction, and perform a set of sensitivity model runs to identify coseismic deformation patterns resulting in highest runup at a given community. Because of the extra fine discretization of the interface, we can prescribe variable slip patterns, using simple parameters to describe slip variations in the along-strike and down-dip directions. Since it was demonstrated by studies of the 1964 tsunami that changes in slip distribution result in significant variations in the local tsunami wave field, we expect that the near-field tsunami runup in target communities will be highly sensitive to variability of slip along the rupture area. We perform simulations for each source scenario using AEIC's numerical model of tsunami propagation and runup, which is validated through a set of analytical benchmarks and tested against laboratory and field data. Results of numerical modeling combined with historical observations are compiled on inundation maps and used for site-specific tsunami hazard assessment by local emergency planners.

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.

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.

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.

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

Alaska Tidal Datum Portal - Alaska Tidal Datum Calculator | Alaska Division

Science.gov Websites

Coastal Hazards Program Guide to Geologic Hazards in Alaska MAPTEACH Tsunami Inundation Mapping Energy Portal main content Alaska Tidal Datum Portal Unambiguous vertical datums in the coastal environment are projects to ensure protection of human life, property, and the coastal environment. January 2017 - Update

General Vulnerability and Exposure Profile to Tsunami in Puerto Rico

NASA Astrophysics Data System (ADS)

Ruiz, R.; Huérfano-Moreno, V.

2012-12-01

The Puerto Rico archipelago, located in the seismically active Caribbean region, has been directly affected by tsunamis in the last two centuries. The M 7.3 tsunamigenic earthquake, which occurred on October 11, 1918, caused $29 million in damage, death of 116 people and 100 residents were reported as missing. Presently, deficiencies on urban planning have induced an increase on the number of vulnerable people living inside the tsunami flood areas. Tsunami-prone areas have been delimited for Puerto Rico based on numerical tsunami modeling. However, the demographic, social and physical (e.g. critical and essential facilities) characteristics of these areas have not been documented in detail. We are conducting a municipality and community-level tsunami vulnerability and exposure study using Geographical Information System (GIS) tool. The results of our study are being integrated into the Puerto Rico Disaster Decision Support Tool (DDST). The DDST is a tool that brings access, at no cost, to a variety of updated geo-referenced information for Puerto Rico. This tool provides internet-based scalable maps that will aid emergency managers and decision-makers on their responsibilities and will improve Puerto Rico communities' resilience against tsunami hazard. This project aims to provide an initial estimate of Puerto Rico vulnerability and exposure to tsunami and brings to the community a technological tool that will help increase their awareness of this hazard and to assist them on their decisions.

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).

Lessons on vulnerability from the 2011 Tohoku earthquake for Indonesia and the United States

NASA Astrophysics Data System (ADS)

Sugimoto, M.; Dengler, L.

2011-12-01

The 2011 Tohoku earthquake and tsunami shocked people relevant for tsunami disaster risk reduction all over the world because such people thought Tohoku has often attacked by tsunamis and has declared one of the most wellprepared areas for tsunami in the world. Each author has separately promoted tsunami education to community in Indonesia for 7 years after the 2004 Indian Ocean tsunami and California US for 19 years after the1992 M7.2 Cape Mendocino earthquake. In order to learn the lesson from the 2011 Tohoku earthquake and tsunami and feedback to Indonesia, US and International society, we examined some of the factors that contributed to impacts in Tohoku based on field reconnaissance and reports from other organizations. The biggest factors exacerbating losses were the underestimation M8 of the real tsunami size M9 in design of prevention structures and evacuation planning coupled with a perception of individuals that they were not at risk. Approximately 86 % of the tsunami victims were in areas outside the mapped tsunami hazard zone in Unosumai town, Iwate. At least 100 chosen tsunami evacuation buildings were either overtopped or structurally toppled by the tsunami. More than 200 people died in the first story gymnasium of elementary school beside the river and canal in areas outside the mapped tsunami hazard zone in Higashi-Matsushima city Miyagi. Around 80 students sacrificed in Okawa Elementary school in Ishinomaki city Miyagi. Additional factors affecting vulnerability included people who were in safe areas at the time of the earthquake, returning to hazard zones after feeling the earthquake to rescue relatives or possessions, and relying on cars for evacuation. Factors that enhanced resilience include the good performance of most structures to earthquake ground shaking and the performance of the tsunami early warning system in stopping trains and shutting down other critical systems. Although power was out in most of the affected region, some cell phones and automobile car radios worked in many areas and were able to provide some warning guidance. Individuals who were able to improvise and make changes in their evacuation plans and routes may have been more likely to survive. As for US, it has triggered a re-examination of how slip and secondary fault rupture may affect the size of the tsunami and engendered debate about how to treat uncertainty in model results while it has not changed the maximum magnitude estimate for an earthquake on the Cascadia subduction zone, it has triggered a re-examination of how slip and secondary fault rupture may affect the size of the tsunami and engendered debate about how to treat uncertainty in model results. It has also raised the priority of FEMA's catastrophic response planning efforts for a great Cascadia earthquake and has invigorated states and local coastal jurisdiction's planning, education, and outreach efforts. Indonesia has been on the way to prepare for tsunami from the Tohoku model after the 2004 Indian Ocean tsunami. I stopped the plan make signboards of numerical tsunami height in Padang Indonesia because such signboards were not effective in Tohoku in this time. We introduce new plans 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.

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.

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.

The Use of Intensity Scales In Exploiting Tsunami Historical Databases

NASA Astrophysics Data System (ADS)

Barberopoulou, A.; Scheele, F.

2015-12-01

Post-disaster assessments for historical tsunami events (>15 years old) are either scarce or contain limited information. In this study, we are assessing ways to examine tsunami impacts by utilizing data from old events, but more importantly we examine how to best utilize information contained in tsunami historical databases, in order to provide meaningful products that describe the impact of the event. As such, a tsunami intensity scale was applied to two historical events that were observed in New Zealand (one local and one distant), in order to utilize the largest possible number of observations in our dataset. This is especially important for countries like New Zealand where the tsunami historical record is short, going back to only the 19th century, and where instrument recordings are only available for the most recent events. We found that despite a number of challenges in using intensities -uncertainties partly due to limitations of historical event data - these data with the help of GIS tools can be used to produce hazard maps and offer an alternative way to exploit tsunami historical records. Most importantly the assignment of intensities at each point of observation allows for utilization of many more observations than if one depends on physical information alone, such as water heights. We hope these results may be used towards developing a well-defined methodology for hazard assessments, and refine our knowledge for past tsunami events for which the tsunami sources are largely unknown, and also for when physical quantities describing the tsunami (e.g. water height, flood depth, run-up) are scarce.

Numerical Simulation of Several Tectonic Tsunami Sources at the Caribbean Basin

NASA Astrophysics Data System (ADS)

Chacon-Barrantes, S. E.; Lopez, A. M.; Macias, J.; Zamora, N.; Moore, C. W.; Llorente Isidro, M.

2016-12-01

The Tsunami Hazard Assessment Working Group (WG2) of the Intergovernmental Coordination Group for the Tsunami and Other Coastal Hazards Early Warning System for the Caribbean and Adjacent Regions (ICG/CARIBE-EWS), has been tasked to identify tsunami sources for the Caribbean region and evaluate their effects along Caribbean coasts. A list of tectonic sources was developed and presented at the Fall 2015 AGU meeting and the WG2 is currently working on a list of non-tectonic sources. In addition, three Experts Meetings have already been held in 2016 to define worst-case, most credible scenarios for southern Hispaniola and Central America. The WG2 has been tasked to simulate these scenarios to provide an estimate of the resulting effects on coastal areas within the Caribbean. In this study we simulated tsunamis with two leading numerical models (NEOWAVE and Tsunami-HySEA) to compare results among them and report on the consequences for the Caribbean region if a tectonically-induced tsunami occurs in any of these postulated sources. The considered sources are located offshore Central America, at the North Panamá Deformed Belt (NPDB), at the South Caribbean Deformed Belt (SCDB) and around La Hispaniola Island. Results obtained in this study are critical to develop a catalog of scenarios that can be used in future CaribeWave exercises, as well as their usage for ICG/CARIBE-EWS member states as input to model tsunami inundation for their coastal locations. Data from inundation parameters are an additional step to produce tsunami evacuation maps, and develop plans and procedures to increase tsunami awareness and preparedness within the Caribbean.

What caused a large number of fatalities in the Tohoku earthquake?

NASA Astrophysics Data System (ADS)

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

2012-04-01

The Mw9.0 earthquake caused 20,000 deaths and missing persons in northeastern Japan. 115 years prior to this event, there were three historical tsunamis that struck the region, one of which is a "tsunami earthquake" resulted with a death toll of 22,000. Since then, numerous breakwaters were constructed along the entire northeastern coasts and tsunami evacuation drills were carried out and hazard maps were distributed to local residents on numerous communities. However, despite the constructions and preparedness efforts, the March 11 Tohoku earthquake caused numerous fatalities. The strong shaking lasted three minutes or longer, thus all residents recognized that this is the strongest and longest earthquake that they had been ever experienced in their lives. The tsunami inundated an enormous area at about 560km2 over 35 cities along the coast of northeast Japan. To find out the reasons behind the high number of fatalities due to the March 11 tsunami, we interviewed 150 tsunami survivors at public evacuation shelters in 7 cities mainly in Iwate prefecture in mid-April and early June 2011. Interviews were done for about 30min or longer focused on their evacuation behaviors and those that they had observed. On the basis of the interviews, we found that residents' decisions not to evacuate immediately were partly due to or influenced by earthquake science results. Below are some of the factors that affected residents' decisions. 1. Earthquake hazard assessments turned out to be incorrect. Expected earthquake magnitudes and resultant hazards in northeastern Japan assessed and publicized by the government were significantly smaller than the actual Tohoku earthquake. 2. Many residents did not receive accurate tsunami warnings. The first tsunami warning were too small compared with the actual tsunami heights. 3. The previous frequent warnings with overestimated tsunami height influenced the behavior of the residents. 4. Many local residents above 55 years old experienced the 1960 Chile tsunami, which was significantly smaller than that of the 11 March tsunami. This sense of "knowing" put their lives at high risk. 5. Some local residents believed that with the presence of a breakwater, only slight flooding would occur. 6. Many people did not understand why tsunami is created under the sea. Therefore, relation of earthquake and tsunami is not quite linked to many people. These interviews made it clear that many deaths resulted because current technology and earthquake science underestimated tsunami heights, warning systems failed, and breakwaters were not strong or high enough. However, even if these problems occur in future earthquakes, better knowledge regarding earthquakes and tsunami hazards could save more lives. In an elementary school when children have fresh brain, it is necessary for them to learn the basic mechanism of tsunami generation.

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.

Potential coping capacities to avoid tsunamis in Mentawai

NASA Astrophysics Data System (ADS)

Panjaitan, Berton; Gomez, Christopher; Pawson, Eric

2017-07-01

In 2010 a tsunamigenic earthquake triggered tsunami waves reaching the Mentawai archipelago in less than ten minutes. Similar events can occur any time as seismic scholars predict enormous energy remains trapped on the Sunda Megathrust - approximately 30 km offshore from the archipelago. Therefore, the local community of Mentawai is vulnerable to tsunami hazards. In the absence of modern technology to monitor the sea surface interventions, existing strategies need to be improved. This study was based on a qualitative research and literature review about developing coping capacity on tsunami hazards for Mentawai. A community early-warning system is the main strategy to develop the coping capacity at the community level. This consists of risk knowledge, monitoring, warning dissemination, and capability response. These are interlocked and are an end-to-end effort. From the study, the availability of risk assessments and risk mappings were mostly not found at dusun, whereas they are effective to increase tsunami risk knowledge. Also, the monitoring of tsunami waves can be maximized by strengthening and expanding the community systems for the people to avoid the waves. Moreover, the traditional tools are potential to deliver warnings. Lastly, although the local government has provided a few public facilities to increase the response capability, the people often ignore them. Therefore, their traditional values should be revitalized.

High resolution tsunami modelling for the evaluation of potential risk areas in Setúbal (Portugal)

NASA Astrophysics Data System (ADS)

Ribeiro, J.; Silva, A.; Leitão, P.

2011-08-01

The use of high resolution hydrodynamic modelling to simulate the potential effects of tsunami events can provide relevant information about the most probable inundation areas. Moreover, the consideration of complementary data such as the type of buildings, location of priority equipment, type of roads, enables mapping of the most vulnerable zones, computing of the expected damage on man-made structures, constrain of the definition of rescue areas and escape routes, adaptation of emergency plans and proper evaluation of the vulnerability associated with different areas and/or equipment. Such an approach was used to evaluate the specific risks associated with a potential occurrence of a tsunami event in the region of Setúbal (Portugal), which was one of the areas most seriously affected by the 1755 tsunami. In order to perform an evaluation of the hazard associated with the occurrence of a similar event, high resolution wave propagation simulations were performed considering different potential earthquake sources with different magnitudes. Based on these simulations, detailed inundation maps associated with the different events were produced. These results were combined with the available information on the vulnerability of the local infrastructures (building types, roads and streets characteristics, priority buildings) in order to impose restrictions in the production of high-scale potential damage maps, escape routes and emergency routes maps.

Tsunami hazard and risk assessment in El Salvador

NASA Astrophysics Data System (ADS)

González, M.; González-Riancho, P.; Gutiérrez, O. Q.; García-Aguilar, O.; Aniel-Quiroga, I.; Aguirre, I.; Alvarez, J. A.; Gavidia, F.; Jaimes, I.; Larreynaga, J. A.

2012-04-01

Tsunamis are relatively infrequent phenomena representing a greater threat than earthquakes, hurricanes and tornadoes, causing the loss of thousands of human lives and extensive damage to coastal infrastructure around the world. Several works have attempted to study these phenomena in order to understand their origin, causes, evolution, consequences, and magnitude of their damages, to finally propose mechanisms to protect coastal societies. Advances in the understanding and prediction of tsunami impacts allow the development of adaptation and mitigation strategies to reduce risk on coastal areas. This work -Tsunami Hazard and Risk Assessment in El Salvador-, funded by AECID during the period 2009-12, examines the state of the art and presents a comprehensive methodology for assessing the risk of tsunamis at any coastal area worldwide and applying it to the coast of El Salvador. The conceptual framework is based on the definition of Risk as the probability of harmful consequences or expected losses resulting from a given hazard to a given element at danger or peril, over a specified time period (European Commission, Schneiderbauer et al., 2004). The HAZARD assessment (Phase I of the project) is based on propagation models for earthquake-generated tsunamis, developed through the characterization of tsunamigenic sources -sismotectonic faults- and other dynamics under study -tsunami waves, sea level, etc.-. The study area is located in a high seismic activity area and has been hit by 11 tsunamis between 1859 and 1997, nine of them recorded in the twentieth century and all generated by earthquakes. Simulations of historical and potential tsunamis with greater or lesser affection to the country's coast have been performed, including distant sources, intermediate and close. Deterministic analyses of the threats under study -coastal flooding- have been carried out, resulting in different hazard maps (maximum wave height elevation, maximum water depth, minimum tsunami arrival time, maximum flooding level or "Run-up", hazard degree for people based on incipient velocity for people instability) along the coast of El Salvador and at some relevant locations (high resolution analysis). The VULNERABILITY assessment of the exposed elements (Phase II of the project) is based on an integrated approach which is essential given the complexity of coastal areas. A set of indices and indicators have been developed supported by a Geographic Information System that allows graphical representation of physical, environmental, social, economic and infrastructure characteristics of the coast. Different spatial and temporal scales have been also considered in this project to calculate the risk, since both factors would change the amount and type of exposed elements and their vulnerability. A final global RISK analysis (hazard, exposure and vulnerability analysis for each dimension -human, environmental, socioeconomic and infrastructure- and both temporal and spatial scales) allows identifying weaknesses, gaps and special needs to cope with a tsunami event and, therefore, will result in a set of risk reduction measures, including adaptation and mitigation measures.

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.

Progress in NTHMP Hazard Assessment

USGS Publications Warehouse

Gonzalez, F.I.; Titov, V.V.; Mofjeld, H.O.; Venturato, A.J.; Simmons, R.S.; Hansen, R.; Combellick, Rodney; Eisner, R.K.; Hoirup, D.F.; Yanagi, B.S.; Yong, S.; Darienzo, M.; Priest, G.R.; Crawford, G.L.; Walsh, T.J.

2005-01-01

The Hazard Assessment component of the U.S. National Tsunami Hazard Mitigation Program has completed 22 modeling efforts covering 113 coastal communities with an estimated population of 1.2 million residents that are at risk. Twenty-three evacuation maps have also been completed. Important improvements in organizational structure have been made with the addition of two State geotechnical agency representatives to Steering Group membership, and progress has been made on other improvements suggested by program reviewers. ?? Springer 2005.

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.

Changes in Tsunami Risk Perception in Northern Chile After the April 1 2014 Tsunami

NASA Astrophysics Data System (ADS)

Carvalho, L.; Lagos, M.

2016-12-01

Tsunamis are a permanent risk in the coast of Chile. Apart from that, the coastal settlements and the Chilean State, historically, have underestimated the danger of tsunamis. On April 1 2014, a magnitude Mw 8.2 earthquake and a minor tsunami occurred off the coast of northern Chile. Considering that over decades this region has been awaiting an earthquake that would generate a large tsunami, in this study we inquired if the familiarity with the subject tsunami and the lack of frequent tsunamis or occurrence of non-hazardous tsunamis for people could lead to adaptive responses to underestimate the danger. The purpose of this study was to evaluate the perceived risk of tsunami in the city of Arica, before and after the April 1 2014 event. A questionnaire was designed and applied in two time periods to 547 people living in low coastal areas in Arica. In the first step, the survey was applied in March 2014. While in step 2, new questions were included and the survey was reapplied, a year after the minor tsunami. A descriptive analysis of data was performed, followed by a comparison between means. We identified illusion of invulnerability, especially regarding to assessment that preparedness and education actions are enough. Answers about lack of belief in the occurrence of future tsunamis were also reported. At the same time, there were learning elements identified. After April 1, a larger number of participants described self-protection actions for emergency, as well as performing of preventive actions. In addition, we mapped answers about the tsunami danger degree in different locations in the city, where we observed a high knowledge of it. When compared with other hazards, the concern about tsunamis were very high, lower than earthquakes hazard, but higher than pollution, crime and rain. Moreover, we identified place attachment in answers about sense of security and affective bonds with home and their location. We discussed the relationship between risk perception, illusion of invulnerability and place attachment. Finally, we questioned whether learning elements will remain in time, or if this elements are related to short-term public interest. The April 1 event was not the largest earthquake expected in this subduction zone, therefore, it is extremely important that communities are educated and prepared to live with risk.

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).

Tsunami hazard assessment in El Salvador, Central America, from seismic sources through flooding numerical models

NASA Astrophysics Data System (ADS)

Álvarez-Gómez, J. A.; Aniel-Quiroga, Í.; Gutiérrez-Gutiérrez, O. Q.; Larreynaga, J.; González, M.; Castro, M.; Gavidia, F.; Aguirre-Ayerbe, I.; González-Riancho, P.; Carreño, E.

2013-05-01

El Salvador is the smallest and most densely populated country in Central America; its coast has approximately a length of 320 km, 29 municipalities and more than 700 000 inhabitants. In El Salvador there have been 15 recorded tsunamis between 1859 and 2012, 3 of them causing damages and hundreds of victims. The hazard assessment is commonly based on propagation numerical models for earthquake-generated tsunamis and can be approached from both Probabilistic and Deterministic Methods. A deterministic approximation has been applied in this study as it provides essential information for coastal planning and management. The objective of the research was twofold, on the one hand the characterization of the threat over the entire coast of El Salvador, and on the other the computation of flooding maps for the three main localities of the Salvadorian coast. For the latter we developed high resolution flooding models. For the former, due to the extension of the coastal area, we computed maximum elevation maps and from the elevation in the near-shore we computed an estimation of the run-up and the flooded area using empirical relations. We have considered local sources located in the Middle America Trench, characterized seismotectonically, and distant sources in the rest of Pacific basin, using historical and recent earthquakes and tsunamis. We used a hybrid finite differences - finite volumes numerical model in this work, based on the Linear and Non-linear Shallow Water Equations, to simulate a total of 24 earthquake generated tsunami scenarios. In the western Salvadorian coast, run-up values higher than 5 m are common, while in the eastern area, approximately from La Libertad to the Gulf of Fonseca, the run-up values are lower. The more exposed areas to flooding are the lowlands in the Lempa River delta and the Barra de Santiago Western Plains. The results of the empirical approximation used for the whole country are similar to the results obtained with the high resolution numerical modelling, being a good and fast approximation to obtain preliminary tsunami hazard estimations. In Acajutla and La Libertad, both important tourism centres being actively developed, flooding depths between 2 and 4 m are frequent, accompanied with high and very high person instability hazard. Inside the Gulf of Fonseca the impact of the waves is almost negligible.

Tsunami hazard assessment in El Salvador, Central America, from seismic sources through flooding numerical models.

NASA Astrophysics Data System (ADS)

Álvarez-Gómez, J. A.; Aniel-Quiroga, Í.; Gutiérrez-Gutiérrez, O. Q.; Larreynaga, J.; González, M.; Castro, M.; Gavidia, F.; Aguirre-Ayerbe, I.; González-Riancho, P.; Carreño, E.

2013-11-01

El Salvador is the smallest and most densely populated country in Central America; its coast has an approximate length of 320 km, 29 municipalities and more than 700 000 inhabitants. In El Salvador there were 15 recorded tsunamis between 1859 and 2012, 3 of them causing damages and resulting in hundreds of victims. Hazard assessment is commonly based on propagation numerical models for earthquake-generated tsunamis and can be approached through both probabilistic and deterministic methods. A deterministic approximation has been applied in this study as it provides essential information for coastal planning and management. The objective of the research was twofold: on the one hand the characterization of the threat over the entire coast of El Salvador, and on the other the computation of flooding maps for the three main localities of the Salvadorian coast. For the latter we developed high-resolution flooding models. For the former, due to the extension of the coastal area, we computed maximum elevation maps, and from the elevation in the near shore we computed an estimation of the run-up and the flooded area using empirical relations. We have considered local sources located in the Middle America Trench, characterized seismotectonically, and distant sources in the rest of Pacific Basin, using historical and recent earthquakes and tsunamis. We used a hybrid finite differences-finite volumes numerical model in this work, based on the linear and non-linear shallow water equations, to simulate a total of 24 earthquake-generated tsunami scenarios. Our results show that at the western Salvadorian coast, run-up values higher than 5 m are common, while in the eastern area, approximately from La Libertad to the Gulf of Fonseca, the run-up values are lower. The more exposed areas to flooding are the lowlands in the Lempa River delta and the Barra de Santiago Western Plains. The results of the empirical approximation used for the whole country are similar to the results obtained with the high-resolution numerical modelling, being a good and fast approximation to obtain preliminary tsunami hazard estimations. In Acajutla and La Libertad, both important tourism centres being actively developed, flooding depths between 2 and 4 m are frequent, accompanied with high and very high person instability hazard. Inside the Gulf of Fonseca the impact of the waves is almost negligible.

Hazard Assessment and Early Warning of Tsunamis: Lessons from the 2011 Tohoku earthquake

NASA Astrophysics Data System (ADS)

Satake, K.

2012-12-01

The March 11, 2011 Tohoku earthquake (M 9.0) was the largest earthquake in Japanese history, and was the best recorded subduction-zone earthquakes in the world. In particular, various offshore geophysical observations revealed large horizontal and vertical seafloor movements, and the tsunami was recorded on high-quality, high-sampling gauges. Analysis of such tsunami waveforms shows a temporal and spatial slip distribution during the 2011 Tohoku earthquake. The fault rupture started near the hypocenter and propagated into both deep and shallow parts of the plate interface. Very large, ~25 m, slip off Miyagi on the deep part of plate interface corresponds to an interplate earthquake of M 8.8, the location and size similar to 869 Jogan earthquake model, and was responsible for the large tsunami inundation in Sendai and Ishinomaki plains. Huge slip, more than 50 m, occurred on the shallow part near the trench axis ~3 min after the earthquake origin time. This delayed shallow rupture (M 8.8) was similar to the 1896 "tsunami earthquake," and was responsible for the large tsunami on the northern Sanriku coast, measured at ~100 km north of the largest slip. Thus the Tohoku earthquake can be decomposed into an interplate earthquake and the triggered "tsunami earthquake." The Japan Meteorological Agency issued tsunami warning 3 minutes after the earthquake, and saved many lives. However, their initial estimation of tsunami height was underestimated, because the earthquake magnitude was initially estimated as M 7.9, hence the computed tsunami heights were lower. The JMA attempts to improve the tsunami warning system, including technical developments to estimate the earthquake size in a few minutes by using various and redundant information, to deploy and utilize the offshore tsunami observations, and to issue a warning based on the worst case scenario if a possibility of giant earthquake exists. Predicting a trigger of another large earthquake would still be a challenge. Tsunami hazard assessments or long-term forecast of earthquakes have not considered such a triggering or simultaneous occurrence of different types of earthquakes. The large tsunami at the Fukushima nuclear power station was due to the combination of the deep and shallow slip. Disaster prevention for low-frequency but large-scale hazard must be considered. The Japanese government established a general policy to for two levels: L1 and L2. The L2 tsunamis are the largest possible tsunamis with low frequency of occurrence, but cause devastating disaster once they occur. For such events, saving people's lives is the first priority and soft measures such as tsunami hazard maps, evacuation facilities or disaster education will be prepared. The L1 tsunamis are expected to occur more frequently, typically once in a few decades, for which hard countermeasures such as breakwater must be prepared to protect lives and properties of residents as well as economic and industrial activities.

Modelling tsunami inundation for risk analysis at the Andaman Sea Coast of Thailand

NASA Astrophysics Data System (ADS)

Kaiser, G.; Kortenhaus, A.

2009-04-01

The mega-tsunami of Dec. 26, 2004 strongly impacted the Andaman Sea coast of Thailand and devastated coastal ecosystems as well as towns, settlements and tourism resorts. In addition to the tragic loss of many lives, the destruction or damage of life-supporting infrastructure, such as buildings, roads, water & power supply etc. caused high economic losses in the region. To mitigate future tsunami impacts there is a need to assess the tsunami hazard and vulnerability in flood prone areas at the Andaman Sea coast in order to determine the spatial distribution of risk and to develop risk management strategies. In the bilateral German-Thai project TRAIT research is performed on integrated risk assessment for the Provinces Phang Nga and Phuket in southern Thailand, including a hazard analysis, i.e. modelling tsunami propagation to the coast, tsunami wave breaking and inundation characteristics, as well as vulnerability analysis of the socio-economic and the ecological system in order to determine the scenario-based, specific risk for the region. In this presentation results of the hazard analysis and the inundation simulation are presented and discussed. Numerical modelling of tsunami propagation and inundation simulation is an inevitable tool for risk analysis, risk management and evacuation planning. While numerous investigations have been made to model tsunami wave generation and propagation in the Indian Ocean, there is still a lack in determining detailed inundation patterns, i.e. water depth and flow dynamics. However, for risk management and evacuation planning this knowledge is essential. As the accuracy of the inundation simulation is strongly depending on the available bathymetric and the topographic data, a multi-scale approach is chosen in this work. The ETOPO Global Relief Model as a bathymetric basis and the Shuttle Radar Topography Mission (SRTM90) have been widely applied in tsunami modelling approaches as these data are free and almost world-wide available. However, to model tsunami-induced inundation for risk analysis and management purposes the accuracy of these data is not sufficient as the processes in the near-shore zone cannot be modelled accurately enough and the spatial resolution of the topography is weak. Moreover, the SRTM data provide a digital surface model which includes vegetation and buildings in the surface description. To improve the data basis additional bathymetric data were used in the near shore zone of the Phang Nga and Phuket coastlines and various remote sensing techniques as well as additional GPS measurements were applied to derive a high resolution topography from satellite and airborne data. Land use classifications and filter methods were developed to correct the digital surface models to digital elevation models. Simulations were then performed with a non-linear shallow water model to model the 2004 Asian Tsunami and to simulate possible future ones. Results of water elevation near the coast were compared with field measurements and observations, and the influence of the resolution of the topography on inundation patterns like water depth, velocity, dispersion and duration of the flood were analysed. The inundation simulation provides detailed hazard maps and is considered a reliable basis for risk assessment and risk zone mapping. Results are regarded vital for estimation of tsunami induced damages and evacuation planning. Results of the aforementioned simulations will be discussed during the conference. Differences of the numerical results using topographic data of different scales and modified by different post processing techniques will be analysed and explained. Further use of the results with respect to tsunami risk analysis and management will also be demonstrated.

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.

Deterministic Tectonic Origin Tsunami Hazard Analysis for the Eastern Mediterranean and its Connected Seas

NASA Astrophysics Data System (ADS)

Necmioglu, O.; Meral Ozel, N.

2014-12-01

Accurate earthquake source parameters are essential for any tsunami hazard assessment and mitigation, including early warning systems. Complex tectonic setting makes the a priori accurate assumptions of earthquake source parameters difficult and characterization of the faulting type is a challenge. Information on tsunamigenic sources is of crucial importance in the Eastern Mediterranean and its Connected Seas, especially considering the short arrival times and lack of offshore sea-level measurements. In addition, the scientific community have had to abandon the paradigm of a ''maximum earthquake'' predictable from simple tectonic parameters (Ruff and Kanamori, 1980) in the wake of the 2004 Sumatra event (Okal, 2010) and one of the lessons learnt from the 2011 Tohoku event was that tsunami hazard maps may need to be prepared for infrequent gigantic earthquakes as well as more frequent smaller-sized earthquakes (Satake, 2011). We have initiated an extensive modeling study to perform a deterministic Tsunami Hazard Analysis for the Eastern Mediterranean and its Connected Seas. Characteristic earthquake source parameters (strike, dip, rake, depth, Mwmax) at each 0.5° x 0.5° size bin for 0-40 km depth (total of 310 bins) and for 40-100 km depth (total of 92 bins) in the Eastern Mediterranean, Aegean and Black Sea region (30°N-48°N and 22°E-44°E) have been assigned from the harmonization of the available databases and previous studies. These parameters have been used as input parameters for the deterministic tsunami hazard modeling. Nested Tsunami simulations of 6h duration with a coarse (2 arc-min) and medium (1 arc-min) grid resolution have been simulated at EC-JRC premises for Black Sea and Eastern and Central Mediterranean (30°N-41.5°N and 8°E-37°E) for each source defined using shallow water finite-difference SWAN code (Mader, 2004) for the magnitude range of 6.5 - Mwmax defined for that bin with a Mw increment of 0.1. Results show that not only the earthquakes resembling the well-known historical earthquakes such as AD 365 or AD 1303 in the Hellenic Arc, but also earthquakes with lower magnitudes do constitute to the tsunami hazard in the study area.

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?

Pedestrian Evacuation Analysis for Tsunami Hazards

NASA Astrophysics Data System (ADS)

Jones, J. M.; Ng, P.; Wood, N. J.

2014-12-01

Recent catastrophic tsunamis in the last decade, as well as the 50th anniversary of the 1964 Alaskan event, have heightened awareness of the threats these natural hazards present to large and increasing coastal populations. For communities located close to the earthquake epicenter that generated the tsunami, strong shaking may also cause significant infrastructure damage, impacting the road network and hampering evacuation. There may also be insufficient time between the earthquake and first wave arrival to rely on a coordinated evacuation, leaving at-risk populations to self-evacuate on foot and across the landscape. Emergency managers evaluating these coastal risks need tools to assess the evacuation potential of low-lying areas in order to discuss mitigation options, which may include vertical evacuation structures to provide local safe havens in vulnerable communities. The U.S. Geological Survey has developed the Pedestrian Evacuation Analyst software tool for use by researchers and emergency managers to assist in the assessment of a community's evacuation potential by modeling travel times across the landscape and producing both maps of travel times and charts of population counts with corresponding times. The tool uses an anisotropic (directionally dependent) least cost distance model to estimate evacuation potential and allows for the variation of travel speed to measure its effect on travel time. The effectiveness of vertical evacuation structures on evacuation time can also be evaluated and compared with metrics such as travel time maps showing each structure in place and graphs displaying the percentage change in population exposure for each structure against the baseline. Using the tool, travel time maps and at-risk population counts have been generated for some coastal communities of the U.S. Pacific Northwest and Alaska. The tool can also be used to provide valuable decision support for tsunami vertical evacuation siting.

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.

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)

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.

2014-05-01

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 on 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 hazard at the coast 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 through 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 larger maximum magnitudes along the Sunda Arc. The annual probability of experiencing a tsunami with a height at the coast of > 0.5 m 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.

Cascadia Earthquake and Tsunami Scenario for California's North Coast

NASA Astrophysics Data System (ADS)

Dengler, L.

2006-12-01

In 1995 the California Division of Mines and Geology (now the California Geological Survey) released a planning scenario for an earthquake on the southern portion of the Cascadia subduction zone (CSZ). This scenario was the 8th and last of the Earthquake Planning Scenarios published by CDMG. It was the largest magnitude CDMG scenario, an 8.4 earthquake rupturing the southern 200 km of the CSZ, and it was the only scenario to include tsunami impacts. This scenario event has not occurred in historic times and depicts impacts far more severe than any recent earthquake. The local tsunami hazard is new; there is no written record of significant local tsunami impact in the region. The north coast scenario received considerable attention in Humboldt and Del Norte Counties and contributed to a number of mitigation efforts. The Redwood Coast Tsunami Work Group (RCTWG), an organization of scientists, emergency managers, government agencies, and businesses from Humboldt, Mendocino, and Del Norte Counties, was formed in 1996 to assist local jurisdictions in understanding the implications of the scenario and to promote a coordinated, consistent mitigation program. The group has produced print and video materials and promoted response and evacuation planning. Since 1997 the RCTWG has sponsored an Earthquake Tsunami Education Room at county fairs featuring preparedness information, hands-on exhibits and regional tsunami hazard maps. Since the development of the TsunamiReady Program in 2001, the RCTWG facilitates community TsunamiReady certification. To assess the effectiveness of mitigation efforts, five telephone surveys between 1993 and 2001 were conducted by the Humboldt Earthquake Education Center. A sixth survey is planned for this fall. Each survey includes between 400 and 600 respondents. Over the nine 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. It is not surprising that the earlier surveys showed increases as several strong earthquakes occurred in the area between 1992 and 1995 and there was considerable media attention. But the 2001 survey, seven years after the last widely felt event, still shows significant increases in almost all preparedness indicators. The 1995 CDMG scenario was not the sole reason for the increased interest in earthquake and tsunami hazards in the area, but the scenario gave government recognition to an event that was previously only considered seriously in the scientific community and has acted as a catalyst for mitigation and planning efforts.

Global mapping of nonseismic sea level oscillations at tsunami timescales.

PubMed

Vilibić, Ivica; Šepić, Jadranka

2017-01-18

Present investigations of sea level extremes are based on hourly data measured at coastal tide gauges. The use of hourly data restricts existing global and regional analyses to periods larger than 2 h. However, a number of processes occur at minute timescales, of which the most ruinous are tsunamis. Meteotsunamis, hazardous nonseismic waves that occur at tsunami timescales over limited regions, may also locally dominate sea level extremes. Here, we show that nonseismic sea level oscillations at tsunami timescales (<2 h) may substantially contribute to global sea level extremes, up to 50% in low-tidal basins. The intensity of these oscillations is zonally correlated with mid-tropospheric winds at the 99% significance level, with the variance doubling from the tropics and subtropics to the mid-latitudes. Specific atmospheric patterns are found during strong events at selected locations in the World Ocean, indicating a globally predominant generation mechanism. Our analysis suggests that these oscillations should be considered in sea level hazard assessment studies. Establishing a strong correlation between nonseismic sea level oscillations at tsunami timescales and atmospheric synoptic patterns would allow for forecasting of nonseismic sea level oscillations for operational use, as well as hindcasting and projection of their effects under past, present and future climates.

Global mapping of nonseismic sea level oscillations at tsunami timescales

PubMed Central

Vilibić, Ivica; Šepić, Jadranka

2017-01-01

Present investigations of sea level extremes are based on hourly data measured at coastal tide gauges. The use of hourly data restricts existing global and regional analyses to periods larger than 2 h. However, a number of processes occur at minute timescales, of which the most ruinous are tsunamis. Meteotsunamis, hazardous nonseismic waves that occur at tsunami timescales over limited regions, may also locally dominate sea level extremes. Here, we show that nonseismic sea level oscillations at tsunami timescales (<2 h) may substantially contribute to global sea level extremes, up to 50% in low-tidal basins. The intensity of these oscillations is zonally correlated with mid-tropospheric winds at the 99% significance level, with the variance doubling from the tropics and subtropics to the mid-latitudes. Specific atmospheric patterns are found during strong events at selected locations in the World Ocean, indicating a globally predominant generation mechanism. Our analysis suggests that these oscillations should be considered in sea level hazard assessment studies. Establishing a strong correlation between nonseismic sea level oscillations at tsunami timescales and atmospheric synoptic patterns would allow for forecasting of nonseismic sea level oscillations for operational use, as well as hindcasting and projection of their effects under past, present and future climates. PMID:28098195

Hazard Evaluation in Valparaíso: the MAR VASTO Project

NASA Astrophysics Data System (ADS)

Indirli, Maurizio; Razafindrakoto, Hoby; Romanelli, Fabio; Puglisi, Claudio; Lanzoni, Luca; Milani, Enrico; Munari, Marco; Apablaza, Sotero

2011-03-01

The Project "MAR VASTO" (Risk Management in Valparaíso/Manejo de Riesgos en Valparaíso), funded by BID/IADB (Banco InterAmericano de Desarrollo/InterAmerican Development Bank), has been managed by ENEA, with an Italian/Chilean joined partnership and the support of local institutions. Valparaíso tells the never-ending story of a tight interaction between society and environment and the city has been declared a Patrimony of Humanity by UNESCO since 2003. The main goals of the project have been to evaluate in the Valparaíso urban area the impact of main hazards (earthquake, tsunami, fire, and landslide), defining scenarios and maps on a geo-referenced GIS database. In particular, for earthquake hazard assessment the realistic modelling of ground motion is a very important base of knowledge for the preparation of groundshaking scenarios which serve as a valid and economic tool to be fruitfully used by civil engineers, supplying a particularly powerful tool for the prevention aspects of Civil Defense. When numerical modelling is successfully compared with records (as in the case of the Valparaíso, 1985 earthquake), the resulting synthetic seismograms permit the generation of groundshaking maps, based upon a set of possible scenario earthquakes. Where no recordings are available for the scenario event, synthetic signals can be used to estimate ground motion without having to wait for a strong earthquake to occur (pre-disaster microzonation). For the tsunami hazard, the available reports, [e.g., SHOA (1999) Carta de Inundacion por Tsunami para la bahia de Valparaíso, Chile, http://www.shoa.cl/servicios/citsu/citsu.php], have been used as the reference documents for the hazard assessment for the Valparaíso site. The deep and detailed studies already carried out by SHOA have been complemented with (a) sets of parametric studies of the tsunamigenic potential of the 1985 and 1906 scenario earthquakes; and (b) analytical modelling of tsunami waveforms for different scenarios, in order to provide a complementary dataset to be used for the tsunami hazard assessment at Valparaíso. In addition, other targeted activities have been carried out, such as architectonic/urban planning studies/vulnerability evaluation for a pilot building stock in a historic area and a vulnerability analysis for three monumental churches. In this paper, a general description of the work is given, taking into account the in situ work that drove the suggestion of guidelines for mitigation actions.

The Pedestrian Evacuation Analyst: geographic information systems software for modeling hazard evacuation potential

USGS Publications Warehouse

Jones, Jeanne M.; Ng, Peter; Wood, Nathan J.

2014-01-01

Recent disasters such as the 2011 Tohoku, Japan, earthquake and tsunami; the 2013 Colorado floods; and the 2014 Oso, Washington, mudslide have raised awareness of catastrophic, sudden-onset hazards that arrive within minutes of the events that trigger them, such as local earthquakes or landslides. Due to the limited amount of time between generation and arrival of sudden-onset hazards, evacuations are typically self-initiated, on foot, and across the landscape (Wood and Schmidtlein, 2012). Although evacuation to naturally occurring high ground may be feasible in some vulnerable communities, evacuation modeling has demonstrated that other communities may require vertical-evacuation structures within a hazard zone, such as berms or buildings, if at-risk individuals are to survive some types of sudden-onset hazards (Wood and Schmidtlein, 2013). Researchers use both static least-cost-distance (LCD) and dynamic agent-based models to assess the pedestrian evacuation potential of vulnerable communities. Although both types of models help to understand the evacuation landscape, LCD models provide a more general overview that is independent of population distributions, which may be difficult to quantify given the dynamic spatial and temporal nature of populations (Wood and Schmidtlein, 2012). Recent LCD efforts related to local tsunami threats have focused on an anisotropic (directionally dependent) path distance modeling approach that incorporates travel directionality, multiple travel speed assumptions, and cost surfaces that reflect variations in slope and land cover (Wood and Schmidtlein, 2012, 2013). The Pedestrian Evacuation Analyst software implements this anisotropic path-distance approach for pedestrian evacuation from sudden-onset hazards, with a particular focus at this time on local tsunami threats. The model estimates evacuation potential based on elevation, direction of movement, land cover, and travel speed and creates a map showing travel times to safety (a time map) throughout a hazard zone. Model results provide a general, static view of the evacuation landscape at different pedestrian travel speeds and can be used to identify areas outside the reach of naturally occurring high ground. In addition, data on the size and location of different populations within the hazard zone can be integrated with travel-time maps to create tables and graphs of at-risk population counts as a function of travel time to safety. As a decision-support tool, the Pedestrian Evacuation Analyst provides the capability to evaluate the effectiveness of various vertical-evacuation structures within a study area, both through time maps of the modeled travel-time landscape with a potential structure in place and through comparisons of population counts within reach of safety. The Pedestrian Evacuation Analyst is designed for use by researchers examining the pedestrian-evacuation potential of an at-risk community. In communities where modeled evacuation times exceed the event (for example, tsunami wave) arrival time, researchers can use the software with emergency managers to assess the area and population served by potential vertical-evacuation options. By automating and managing the modeling process, the software allows researchers to concentrate efforts on providing crucial and timely information on community vulnerability to sudden-onset hazards.

Toward Probabilistic Risk Analyses - Development of a Probabilistic Tsunami Hazard Assessment of Crescent City, CA

NASA Astrophysics Data System (ADS)

González, F. I.; Leveque, R. J.; Hatheway, D.; Metzger, N.

2011-12-01

Risk is defined in many ways, but most are consistent with Crichton's [1999] definition based on the ''risk triangle'' concept and the explicit identification of three risk elements: ''Risk is the probability of a loss, and this depends on three elements: hazard, vulnerability, and exposure. If any of these three elements in risk increases or decreases, then the risk increases or decreases respectively." The World Meteorological Organization, for example, cites Crichton [1999] and then defines risk as [WMO, 2008] Risk = function (Hazard x Vulnerability x Exposure) while the Asian Disaster Reduction Center adopts the more general expression [ADRC, 2005] Risk = function (Hazard, Vulnerability, Exposure) In practice, probabilistic concepts are invariably invoked, and at least one of the three factors are specified as probabilistic in nature. The Vulnerability and Exposure factors are defined in multiple ways in the relevant literature; but the Hazard factor, which is the focus of our presentation, is generally understood to deal only with the physical aspects of the phenomena and, in particular, the ability of the phenomena to inflict harm [Thywissen, 2006]. A Hazard factor can be estimated by a methodology known as Probabilistic Tsunami Hazard Assessment (PTHA) [González, et al., 2009]. We will describe the PTHA methodology and provide an example -- the results of a previous application to Seaside, OR. We will also present preliminary results for a PTHA of Crescent City, CA -- a pilot project and coastal modeling/mapping effort funded by the Federal Emergency Management Agency (FEMA) Region IX office as part of the new California Coastal Analysis and Mapping Project (CCAMP). CCAMP and the PTHA in Crescent City are being conducted under the nationwide FEMA Risk Mapping, Assessment, and Planning (Risk MAP) Program which focuses on providing communities with flood information and tools they can use to enhance their mitigation plans and better protect their citizens.

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

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.

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.

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.

Tsunami Inundation Mapping for the Upper East Coast of the United States

NASA Astrophysics Data System (ADS)

Tehranirad, B.; Kirby, J. T., Jr.; Callahan, J. A.; Shi, F.; Banihashemi, S.; Grilli, S. T.; Grilli, A. R.; Tajalli Bakhsh, T. S.; O'Reilly, C.

2014-12-01

We describe the modeling of tsunami inundation for the Upper US East Coast (USEC) from Ocean City, MD up to Nantucket, MA. and the development of inundation maps for use in emergency management and hazard analysis. Seven tsunami sources were used as initial conditions in order to develop inundation maps based on a Probable Maximum Tsunami approach. Of the seven, two coseismic sources were used; the first being a large earthquake in the Puerto Rico Trench, in the well-known Caribbean Subduction Zone, and the second, an earthquake close to the Azores Gibraltar plate boundary known as the source of the biggest tsunami recorded in the North Atlantic Basin. In addition, four Submarine Mass Failure (SMF) sources located at different locations on the edge of the shelf break were simulated. Finally, the Cumbre Vieja Volcanic (CVV) collapse, located in the Canary Islands, was studied. For this presentation, we discuss modeling results for nearshore tsunami propagation and onshore inundation. A fully nonlinear Boussinesq model (FUNWAVE-TVD) is used to capture the characteristics of tsunami propagation, both nearshore and inland. In addition to the inundation line as the main result of this work, other tsunami quantities such as inundation depth and maximum velocities will be discussed for the whole USEC area. Moreover, a discussion of most vulnerable areas to a possible tsunami in the USEC will be provided. For example, during the inundation simulation process, it was observed that coastal environments with barrier islands are among the hot spots to be significantly impacted by a tsunami. As a result, areas like western Long Island, NY and Atlantic City, NJ are some of the locations that will get extremely affected in case of a tsunami occurrence in the Atlantic Ocean. Finally, the differences between various tsunami sources modeled here will be presented. Although inundation lines for different sources usually follow a similar pattern, there are clear distinctions between the inundation depth and other tsunami features in different areas. Figure below shows the inundation depth for surrounding area of the Ocean City, MD. Figure (a) and (b) are the envelope inundation depth for SMF and coseismic sources. Figure (C) shows the inundation depth for CVV source, which clearly has the largest magnitude amongst the sources studied for this work.

Preliminary Hazard Assessment for Tectonic Tsunamis in the Eastern Mediterranean

NASA Astrophysics Data System (ADS)

Aydin, B.; Bayazitoglu, O.; Sharghi vand, N.; Kanoglu, U.

2017-12-01

There are many critical industrial facilities such as energy production units and energy transmission lines along the southeast coast of Turkey. This region is also active on tourism, and agriculture and aquaculture production. There are active faults in the region, i.e. the Cyprus Fault, which extends along the Mediterranean basin in the east-west direction and connects to the Hellenic Arc. Both the Cyprus Fault and the Hellenic Arc are seismologically active and are capable of generating earthquakes with tsunamigenic potential. Even a small tsunami in the region could cause confusion as shown by the recent 21 July 2017 earthquake of Mw 6.6, which occurred in the Aegean Sea, between Bodrum, Turkey and Kos Island, Greece since region is not prepared for such an event. Moreover, the Mediterranean Sea is one of the most vulnerable regions against sea level rise due to global warming, according to the 5th Report of the Intergovernmental Panel on Climate Change. For these reasons, a marine hazard such as a tsunami can cause much worse damage than expected in the region (Kanoglu et al., Phil. Trans. R. Soc. A 373, 2015). Hence, tsunami hazard assessment is required for the region. In this study, we first characterize earthquakes which have potential to generate a tsunami in the Eastern Mediterranean. Such study is a prerequisite for regional tsunami mitigation studies. For fast and timely predictions, tsunami warning systems usually employ databases that store pre-computed tsunami propagation resulting from hypothetical earthquakes with pre-defined parameters. These pre-defined sources are called tsunami unit sources and they are linearly superposed to mimic a real event, since wave propagation is linear offshore. After investigating historical earthquakes along the Cyprus Fault and the Hellenic Arc, we identified tsunamigenic earthquakes in the Eastern Mediterranean and proposed tsunami unit sources for the region. We used the tsunami numerical model MOST (Titov et al., J. Waterw. Port Coastal Ocean Eng. 142(6), 2016) to numerically solve the nonlinear shallow water-wave equations for calculating offshore wave propagation, shoreline wave heights, and inundation depths through its interface ComMIT (Titov et al., Pure Appl. Geophys. 168(11), 2011) and generated inundation map for one town in the southeast coast of Turkey.

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.

A Probabilistic Tsunami Hazard Study of the Auckland Region, Part II: Inundation Modelling and Hazard Assessment

NASA Astrophysics Data System (ADS)

Lane, E. M.; Gillibrand, P. A.; Wang, X.; Power, W.

2013-09-01

Regional source tsunamis pose a potentially devastating hazard to communities and infrastructure on the New Zealand coast. But major events are very uncommon. This dichotomy of infrequent but potentially devastating hazards makes realistic assessment of the risk challenging. Here, we describe a method to determine a probabilistic assessment of the tsunami hazard by regional source tsunamis with an "Average Recurrence Interval" of 2,500-years. The method is applied to the east Auckland region of New Zealand. From an assessment of potential regional tsunamigenic events over 100,000 years, the inundation of the Auckland region from the worst 100 events is modelled using a hydrodynamic model and probabilistic inundation depths on a 2,500-year time scale were determined. Tidal effects on the potential inundation were included by coupling the predicted wave heights with the probability density function of tidal heights at the inundation site. Results show that the more exposed northern section of the east coast and outer islands in the Hauraki Gulf face the greatest hazard from regional tsunamis in the Auckland region. Incorporating tidal effects into predictions of inundation reduced the predicted hazard compared to modelling all the tsunamis arriving at high tide giving a more accurate hazard assessment on the specified time scale. This study presents the first probabilistic analysis of dynamic modelling of tsunami inundation for the New Zealand coast and as such provides the most comprehensive assessment of tsunami inundation of the Auckland region from regional source tsunamis available to date.

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.

Reducing risk where tectonic plates collide—U.S. Geological Survey subduction zone science plan

USGS Publications Warehouse

Gomberg, Joan S.; Ludwig, Kristin A.; Bekins, Barbara; Brocher, Thomas M.; Brock, John C.; Brothers, Daniel; Chaytor, Jason D.; Frankel, Arthur; Geist, Eric L.; Haney, Matt; Hickman, Stephen H.; Leith, William S.; Roeloffs, Evelyn A.; Schulz, William H.; Sisson, Thomas W.; Wallace, Kristi; Watt, Janet; Wein, Anne M.

2017-06-19

The U.S. Geological Survey (USGS) serves the Nation by providing reliable scientific information and tools to build resilience in communities exposed to subduction zone earthquakes, tsunamis, landslides, and volcanic eruptions. Improving the application of USGS science to successfully reduce risk from these events relies on whole community efforts, with continuing partnerships among scientists and stakeholders, including researchers from universities, other government labs and private industry, land-use planners, engineers, policy-makers, emergency managers and responders, business owners, insurance providers, the media, and the general public.Motivated by recent technological advances and increased awareness of our growing vulnerability to subduction-zone hazards, the USGS is uniquely positioned to take a major step forward in the science it conducts and products it provides, building on its tradition of using long-term monitoring and research to develop effective products for hazard mitigation. This science plan provides a blueprint both for prioritizing USGS science activities and for delineating USGS interests and potential participation in subduction zone science supported by its partners.The activities in this plan address many USGS stakeholder needs:High-fidelity tools and user-tailored information that facilitate increasingly more targeted, neighborhood-scale decisions to mitigate risks more cost-effectively and ensure post-event operability. Such tools may include maps, tables, and simulated earthquake ground-motion records conveying shaking intensity and frequency. These facilitate the prioritization of retrofitting of vulnerable infrastructure;Information to guide local land-use and response planning to minimize development in likely hazardous zones (for example, databases, maps, and scenario documents to guide evacuation route planning in communities near volcanoes, along coastlines vulnerable to tsunamis, and built on landslide-prone terrain);New tools to assess the potential for cascading hazards, such as landslides, tsunamis, coastal changes, and flooding caused by earthquakes or volcanic eruptions;Geospatial models of permanent, widespread land- and sea-level changes that may occur in the immediate aftermath of great (M ≥8.0) subduction zone earthquakes;Strong partnerships between scientists and public safety providers for effective decision making during periods of elevated hazard and risk;Accurate forecasts of far-reaching hazards (for example, ash clouds, tsunamis) to avert catastrophes and unnecessary disruptions in air and sea transportation;Aftershock forecasts to guide decisions about when and where to re-enter, repair, or rebuild buildings and infrastructure, for all types of subduction zone earthquakes.

Projecting community changes in hazard exposure to support long-term risk reduction: A case study of tsunami hazards in the U.S. Pacific Northwest

USGS Publications Warehouse

Sleeter, Benjamin M.; Wood, Nathan J.; Soulard, Christopher E.; Wilson, Tamara

2017-01-01

Tsunamis have the potential to cause considerable damage to communities along the U.S. Pacific Northwest coastline. As coastal communities expand over time, the potential societal impact of tsunami inundation changes. To understand how community exposure to tsunami hazards may change in coming decades, we projected future development (i.e. urban, residential, and rural), households, and residents over a 50-year period (2011–2061) along the Washington, Oregon, and northern California coasts. We created a spatially explicit, land use/land cover, state-and-transition simulation model to project future developed land use based on historical development trends. We then compared our development projection results to tsunami-hazard zones associated with a Cascadia subduction zone (CSZ) earthquake. Changes in tsunami-hazard exposure by 2061 were estimated for 50 incorporated cities, 7 tribal reservations, and 17 counties relative to current (2011) estimates. Across the region, 2061 population exposure in tsunami-hazard zones was projected to increase by 3880 households and 6940 residents. The top ten communities with highest population exposure to CSZ-related tsunamis in 2011 are projected to remain the areas with the highest population exposure by 2061. The largest net population increases in tsunami-hazard zones were projected in the unincorporated portions of several counties, including Skagit, Coos, and Humboldt. Land-change simulation modeling of projected future development serves as an exploratory tool aimed at helping local governments understand the hazard-exposure implications of community growth and to include this knowledge in risk-reduction planning.

Modeling of Marine Natural Hazards in the Lesser Antilles

NASA Astrophysics Data System (ADS)

Zahibo, Narcisse; Nikolkina, Irina; Pelinovsky, Efim

2010-05-01

The Caribbean Sea countries are often affected by various marine natural hazards: hurricanes and cyclones, tsunamis and flooding. The historical data of marine natural hazards for the Lesser Antilles and specially, for Guadeloupe are presented briefly. Numerical simulation of several historical tsunamis in the Caribbean Sea (1755 Lisbon trans-Atlantic tsunami, 1867 Virgin Island earthquake tsunami, 2003 Montserrat volcano tsunami) are performed within the framework of the nonlinear-shallow theory. Numerical results demonstrate the importance of the real bathymetry variability with respect to the direction of propagation of tsunami wave and its characteristics. The prognostic tsunami wave height distribution along the Caribbean Coast is computed using various forms of seismic and hydrodynamics sources. These results are used to estimate the far-field potential for tsunami hazards at coastal locations in the Caribbean Sea. The nonlinear shallow-water theory is also applied to model storm surges induced by tropical cyclones, in particular, cyclones "Lilli" in 2002 and "Dean" in 2007. Obtained results are compared with observed data. The numerical models have been tested against known analytical solutions of the nonlinear shallow-water wave equations. Obtained results are described in details in [1-7]. References [1] N. Zahibo and E. Pelinovsky, Natural Hazards and Earth System Sciences, 1, 221 (2001). [2] N. Zahibo, E. Pelinovsky, A. Yalciner, A. Kurkin, A. Koselkov and A. Zaitsev, Oceanologica Acta, 26, 609 (2003). [3] N. Zahibo, E. Pelinovsky, A. Kurkin and A. Kozelkov, Science Tsunami Hazards. 21, 202 (2003). [4] E. Pelinovsky, N. Zahibo, P. Dunkley, M. Edmonds, R. Herd, T. Talipova, A. Kozelkov and I. Nikolkina, Science of Tsunami Hazards, 22, 44 (2004). [5] N. Zahibo, E. Pelinovsky, E. Okal, A. Yalciner, C. Kharif, T. Talipova and A. Kozelkov, Science of Tsunami Hazards, 23, 25 (2005). [6] N. Zahibo, E. Pelinovsky, T. Talipova, A. Rabinovich, A. Kurkin and I. Nikolkina, Atmospheric Research. 84, 13 (2007). [7] Zahibo, N., Pelinovsky, E., Kurkin, A., and Nikolkina, I. Tsunami hazard for the French West Indies, Lesser Antilles. Integrated Coastal Zone Management (Ed. R. KRISHNAMURTHY). Re-search Publ., Singapore, 2008, 517-535.

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.

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.

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.

Amplification of drawdown and runup over Hawaii's insular shelves by tsunami N-waves from mega Aleutian earthquakes

NASA Astrophysics Data System (ADS)

Bai, Yefei; Yamazaki, Yoshiki; Cheung, Kwok Fai

2018-04-01

The latest tsunami evacuation maps of Hawaii include an extreme scenario triggered by an Mw 9.3 Aleutian earthquake with large near-trench rupture. The tectonic plate motion produces concentrated seafloor uplift toward the deepest part of the trench generating a tsunami with strong non-hydrostatic characters. A parametric study shows the skewed seafloor uplift produces a dispersive leading crest followed by a prominent trough in the form of an N-wave. The trough maintains its depth across the ocean in the absence of side lobes and dispersion. Shifting of the uplift toward the trench tends to deepen the trough, but has diminishing effects on the wave crest away from the source. While the attenuated leading crest produces relatively moderate runup on north-facing shores of the Hawaiian Islands, with matching of the N-wave and shelf resonance periods, the trough produces an impulsive drawdown followed by an energetic upswing with unprecedented runup for a far-field tsunami. A set of control computations without dispersion reaffirms that a non-hydrostatic model is essential to account for these complex wave processes from the source to the shore. This case study highlights the unique tsunami hazards posed by the Aleutians to Hawaii and the role of wave troughs in delineating the impacts for hazard assessment and engineering design.

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.

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.

Standards and Guidelines for Numerical Models for Tsunami Hazard Mitigation

NASA Astrophysics Data System (ADS)

Titov, V.; Gonzalez, F.; Kanoglu, U.; Yalciner, A.; Synolakis, C. E.

2006-12-01

An increased number of nations around the workd need to develop tsunami mitigation plans which invariably involve inundation maps for warning guidance and evacuation planning. There is the risk that inundation maps may be produced with older or untested methodology, as there are currently no standards for modeling tools. In the aftermath of the 2004 megatsunami, some models were used to model inundation for Cascadia events with results much larger than sediment records and existing state-of-the-art studies suggest leading to confusion among emergency management. Incorrectly assessing tsunami impact is hazardous, as recent events in 2006 in Tonga, Kythira, Greece and Central Java have suggested (Synolakis and Bernard, 2006). To calculate tsunami currents, forces and runup on coastal structures, and inundation of coastlines one must calculate the evolution of the tsunami wave from the deep ocean to its target site, numerically. No matter what the numerical model, validation (the process of ensuring that the model solves the parent equations of motion accurately) and verification (the process of ensuring that the model used represents geophysical reality appropriately) both are an essential. Validation ensures that the model performs well in a wide range of circumstances and is accomplished through comparison with analytical solutions. Verification ensures that the computational code performs well over a range of geophysical problems. A few analytic solutions have been validated themselves with laboratory data. Even fewer existing numerical models have been both validated with the analytical solutions and verified with both laboratory measurements and field measurements, thus establishing a gold standard for numerical codes for inundation mapping. While there is in principle no absolute certainty that a numerical code that has performed well in all the benchmark tests will also produce correct inundation predictions with any given source motions, validated codes reduce the level of uncertainty in their results to the uncertainty in the geophysical initial conditions. Further, when coupled with real--time free--field tsunami measurements from tsunameters, validated codes are the only choice for realistic forecasting of inundation; the consequences of failure are too ghastly to take chances with numerical procedures that have not been validated. We discuss a ten step process of benchmark tests for models used for inundation mapping. The associated methodology and algorithmes have to first be validated with analytical solutions, then verified with laboratory measurements and field data. The models need to be published in the scientific literature in peer-review journals indexed by ISI. While this process may appear onerous, it reflects our state of knowledge, and is the only defensible methodology when human lives are at stake. Synolakis, C.E., and Bernard, E.N, Tsunami science before and beyond Boxing Day 2004, Phil. Trans. R. Soc. A 364 1845, 2231--2263, 2005.

Development of Local Amplification Factors in the NEAM Region for Production of Regional Tsunami Hazard Maps

NASA Astrophysics Data System (ADS)

Harbitz, C. B.; Glimsdal, S.; Løvholt, F.; Orefice, S.; Romano, F.; Brizuela, B.; Lorito, S.; Hoechner, A.; Babeyko, A. Y.

2016-12-01

The standard way of estimating tsunami inundation is by applying numerical depth-averaged shallow-water run-up models. However, for a regional Probabilistic Tsunami Hazard Assessment (PTHA), applying such inundation models may be too time-consuming. A faster, yet less accurate procedure, is to relate the near-shore surface elevations at offshore points to maximum shoreline water levels by using a set of amplification factors based on the characteristics of the incident wave and the bathymetric slope. The surface elevation at the shoreline then acts as a rough approximation for the maximum inundation height or run-up height along the shoreline. An amplification-factor procedure based on a limited set of idealized broken shoreline segments has previously been applied to estimate the maximum inundation heights globally. Here, we present a study where this technique is developed further, by taking into account the local bathymetric profiles. We extract a large number of local bathymetric transects over a significant part of the North East Atlantic, the Mediterranean and connected seas (NEAM) region. For each bathymetric transect, we compute the wave amplification from an offshore control point to points close to the shoreline using a linear shallow-water model for waves of different period and polarity with a sinusoidal pulse wave as input. The amplification factors are then tabulated. We present maximum water levels from the amplification factor method, and compare these with results from conventional inundation models. Finally, we demonstrate how the amplification factor method can be convolved with PTHA results to provide regional tsunami hazard maps. This work has been supported by the European Union's Seventh Framework Programme (FP7/2007-2013) under grant agreement 603839 (Project ASTARTE), and the TSUMAPS-NEAM Project (http://www.tsumapsneam.eu/), co-financed by the European Union Civil Protection Mechanism, Agreement Number: ECHO/SUB/2015/718568/PREV26.

Development of Local Amplification Factors in the NEAM Region for Production of Regional Tsunami Hazard Maps

NASA Astrophysics Data System (ADS)

Glimsdal, Sylfest; Løvholt, Finn; Bonnevie Harbitz, Carl; Orefice, Simone; Romano, Fabrizio; Brizuela, Beatriz; Lorito, Stefano; Hoechner, Andreas; Babeyko, Andrey

2017-04-01

The standard way of estimating tsunami inundation is by applying numerical depth-averaged shallow-water run-up models. However, for a regional Probabilistic Tsunami Hazard Assessment (PTHA), applying such inundation models may be too time-consuming. A faster, yet less accurate procedure, is to relate the near-shore surface elevations at offshore points to maximum shoreline water levels by using a set of amplification factors based on the characteristics of the incident wave and the bathymetric slope. The surface elevation at the shoreline then acts as a rough approximation for the maximum inundation height or run-up height along the shoreline. An amplification-factor procedure based on a limited set of idealized broken shoreline segments has previously been applied to estimate the maximum inundation heights globally. Here, we present a study where this technique is developed further, by taking into account the local bathymetric profiles. We extract a large number of local bathymetric transects over a significant part of the North East Atlantic, the Mediterranean and connected seas (NEAM region). For each bathymetric transect, we compute the wave amplification from an offshore control point to points close to the shoreline using a linear shallow-water model for waves of different period and polarity with a sinusoidal pulse wave as input. The amplification factors are then tabulated. We present maximum water levels from the amplification factor method, and compare these with results from conventional inundation models. Finally, we demonstrate how the amplification factor method can be convolved with PTHA results to provide regional tsunami hazard maps. This work has been supported by the European Union's Seventh Framework Programme (FP7/2007-2013) under grant agreement 603839 (Project ASTARTE), and the TSUMAPS-NEAM Project (http://www.tsumapsneam.eu/), co-financed by the European Union Civil Protection Mechanism, Agreement Number: ECHO/SUB/2015/718568/PREV26.

Variations in population vulnerability to tectonic and landslide-related tsunami hazards in Alaska

USGS Publications Warehouse

Wood, Nathan J.; Peters, Jeff

2015-01-01

Effective tsunami risk reduction requires an understanding of how at-risk populations are specifically vulnerable to tsunami threats. Vulnerability assessments primarily have been based on single hazard zones, even though a coastal community may be threatened by multiple tsunami sources that vary locally in terms of inundation extents and wave arrival times. We use the Alaskan coastal communities of Cordova, Kodiak, Seward, Valdez, and Whittier (USA), as a case study to explore population vulnerability to multiple tsunami threats. We use anisotropic pedestrian evacuation models to assess variations in population exposure as a function of travel time out of hazard zones associated with tectonic and landslide-related tsunamis (based on scenarios similar to the 1964 M w9.2 Good Friday earthquake and tsunami disaster). Results demonstrate that there are thousands of residents, employees, and business customers in tsunami hazard zones associated with tectonically generated waves, but that at-risk individuals will likely have sufficient time to evacuate to high ground before waves are estimated to arrive 30–60 min after generation. Tsunami hazard zones associated with submarine landslides initiated by a subduction zone earthquake are smaller and contain fewer people, but many at-risk individuals may not have enough time to evacuate as waves are estimated to arrive in 1–2 min and evacuations may need to occur during earthquake ground shaking. For all hazard zones, employees and customers at businesses far outnumber residents at their homes and evacuation travel times are highest on docks and along waterfronts. Results suggest that population vulnerability studies related to tsunami hazards should recognize non-residential populations and differences in wave arrival times if emergency managers are to develop realistic preparedness and outreach efforts.

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.

Impact of earthquake source complexity and land elevation data resolution on tsunami hazard assessment and fatality estimation

NASA Astrophysics Data System (ADS)

Muhammad, Ario; Goda, Katsuichiro

2018-03-01

This study investigates the impact of model complexity in source characterization and digital elevation model (DEM) resolution on the accuracy of tsunami hazard assessment and fatality estimation through a case study in Padang, Indonesia. Two types of earthquake source models, i.e. complex and uniform slip models, are adopted by considering three resolutions of DEMs, i.e. 150 m, 50 m, and 10 m. For each of the three grid resolutions, 300 complex source models are generated using new statistical prediction models of earthquake source parameters developed from extensive finite-fault models of past subduction earthquakes, whilst 100 uniform slip models are constructed with variable fault geometry without slip heterogeneity. The results highlight that significant changes to tsunami hazard and fatality estimates are observed with regard to earthquake source complexity and grid resolution. Coarse resolution (i.e. 150 m) leads to inaccurate tsunami hazard prediction and fatality estimation, whilst 50-m and 10-m resolutions produce similar results. However, velocity and momentum flux are sensitive to the grid resolution and hence, at least 10-m grid resolution needs to be implemented when considering flow-based parameters for tsunami hazard and risk assessments. In addition, the results indicate that the tsunami hazard parameters and fatality number are more sensitive to the complexity of earthquake source characterization than the grid resolution. Thus, the uniform models are not recommended for probabilistic tsunami hazard and risk assessments. Finally, the findings confirm that uncertainties of tsunami hazard level and fatality in terms of depth, velocity and momentum flux can be captured and visualized through the complex source modeling approach. From tsunami risk management perspectives, this indeed creates big data, which are useful for making effective and robust decisions.

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).

About Us - Alaska Statutes | Alaska Division of Geological & Geophysical

Science.gov Websites

Geologic Hazards in Alaska MAPTEACH Tsunami Inundation Mapping Energy Resources Gas Hydrates Sponsors potential of Alaskan land for production of metals, minerals, fuels, and geothermal resources; the locations declaration of sources, see 4 1, ch. 175, SLA 1980, in the legislative policy on geothermal re- Temporary and

Final report and archive of the swath bathymetry and ancillary data collected in the Puerto Rico Trench region in 2002 and 2003

USGS Publications Warehouse

ten Brink, Uri S.; Danforth, William W.; Polloni, Christopher F.

2013-01-01

In 2002 and 2003, the U.S. Geological Survey (USGS), in cooperation with the National Oceanic and Atmospheric Administration (NOAA), conducted three exploration cruises that mapped for the first time the morphology of the entire tectonic plate boundary stretching from the Dominican Republic in the west to the Lesser Antilles in the east, a distance of approximately 700 kilometers (430 miles). Observations from these three exploration cruises, coupled with computer modeling and published Global Positioning System (GPS) results and earthquake focal mechanisms, have provided new information that is changing the evaluation of the seismic and tsunami hazard from this plate boundary. The observations collected during these cruises also contributed to the basic understanding of the mechanisms that govern plate tectonics, in this case, the creation of the island of Puerto Rico and the deep trench north of it. Results of the sea floor mapping have been an important component of the study of tsunami and earthquake hazards to the northeastern Caribbean and the U.S. Atlantic coast off the United States.

OSL Dating and GPR Mapping of Palaeotsunami Inundation: A 4000-Year History of Indian Ocean Tsunamis as recorded in Sri Lanka

NASA Astrophysics Data System (ADS)

Premasiri, Ranjith; Styles, Peter; Shrira, Victor; Cassidy, Nigel; Schwenninger, Jean-Luc

2015-12-01

To evaluate and mitigate tsunami hazard, as long as possible records of inundations and dates of past events are needed. Coastal sediments deposited by tsunamis (tsunamites) can potentially provide this information. However, of the three key elements needed for reconstruction of palaeotsunamis (identification of sediments, dating and finding the inundation distance) the latter remains the most difficult. The existing methods for estimating the extent of a palaeotsunami inundation rely on extensive excavation, which is not always possible. Here, by analysing tsunamites from Sri Lanka identified using sedimentological and paleontological characteristics, we show that their internal dielectric properties differ significantly from surrounding sediments. The significant difference in the value of dielectric constant of the otherwise almost indistinguishable sediments is due to higher water content of tsunamites. The contrasts were found to be sharp and not to erode over thousands of years; they cause sizeable electromagnetic wave reflections from tsunamite sediments, which permit the use of ground-penetrating radar (GPR) to trace their extent and morphology. In this study of the 2004 Boxing Day Indian Ocean tsunami, we use GPR in two locations in Sri Lanka to trace four identified major palaeotsunami deposits for at least 400 m inland (investigation inland was constrained by inaccessible security zones). The subsurface extent of tsunamites (not available without extensive excavation) provides a good proxy for inundation. The deposits were dated using the established method of optically stimulated luminescence (OSL). This dating, partly corroborated by available historical records and independent studies, contributes to the global picture of tsunami hazard in the Indian Ocean. The proposed method of combined GPR/OSL-based reconstruction of palaeotsunami deposits enables estimates of inundation, recurrence and, therefore, tsunami hazard for any sandy coast with identifiable tsunamite deposits. The method could be also used for anchoring and synchronizing chronologies of ancient civilisations adjacent to the ocean shores.

Examples Not Numbers: Using Historical Events To Present Regional Hazard Information And Stimulate Client Thinking In The Insurance Industry

NASA Astrophysics Data System (ADS)

Pile, J.; Switzer, A.; Gouramanis, C.; Rush, B.; Reynolds, I.; Ryrie, S.; Soria, L.

2013-12-01

Coastal hazards, including tsunami and storm surges, periodically affect many of the world's coasts. Re-insurers and insurance companies use a variety of means to understand and quantify the recurrence interval and risk of such events. Such work is done with the primary aim of placing monetary values on the risk. This collective understanding is often gleaned from the available scientific literature and commonly makes use of maps to delineate areas of risk that assist in communicating risk with clients. In this study we approached the problem of producing an integrated map of coastal hazards (storm and tsunami) for much of southeast Asia (including the Bay of Bengal and northern Australia). Initial analysis showed that assessments based on the short, partial and, for the most part, fragmentary documented history of past events in southeast Asia, would deem almost every coast on the map at high risk of coastal hazards at the regional scale. Although this may be true to a certain extent it would be unjust and unscientific to label entire coastlines 'high risk' as clearly particular sites on any coast are more susceptible to coastal hazards at the local scale. This raises the question: What is the best way to communicate risk at a regional scale without broad generalisations? Our recent collaboration with a major re-insurer lead to the creation of a new form of map (poster) for their clientele using a case study approach aimed at getting clients to think about the details of historical events in the context of localised risk. Using the pedagogical premise of 'Concept, Example, Consequence', we highlight risk in a way that will hopefully stimulate thought among practitioners and provide an alternative to the broad generalizations found in many products in the marketplace. The envisaged outcome is to enhance communication of site-specific risk assessments between stakeholders and encourage a better understanding of localised and regional risk.

Guide to Geologic Hazards in Alaska | Alaska Division of Geological &

Science.gov Websites

content Guide to Geologic Hazards in Alaska Glossary Coastal and river hazards image Coastal and river Storm surge Tsunami Earthquake related hazards image Earthquake related hazards Earthquake Earthquake Subsidence Surface fault rupture Tsunami Uplift Glacier hazards image Glacier hazards Avalanche Debris flow

Geoethical issues in long-term assessment of geohazards and related mitigation policies

NASA Astrophysics Data System (ADS)

Tinti, Stefano; Armigliato, Alberto

2015-04-01

Long-term assessment of large-impact and relatively (or very) infrequent geohazards like earthquakes, tsunamis and volcanic eruptions is nowadays a common practice for geoscientists and many groups have been and are involved in producing global and regional hazard maps in response of an increasing demand of the society. Though the societal needs are the basic motivations for such studies, often this aspect is not pondered enough and a lack of communication between geoscientists and the society might be a serious limit to the effective exploitation of the hazard assessment products and to the development of adequate mitigation policies. This paper is an analysis of the role of geoscientists in the process of the production of long-term assessments of dangerous natural phenomena (such as mapping of seismic, tsunami and volcanic hazards), with special emphasis given to the role of communicators and disseminators (with respect to the general public, to authorities, to restricted specialized audiences…), but also of providers of active support to the planners who should be given key elements for making decision. Geoethics imposes geoscientists to take clear and full responsibilities on the products resulting from their assessments, but also to be aware that these products are valuable insofar they are scientifically sound, known, understandable, and utilizable by a wide universe of users.

2014 Update of the Pacific Northwest portion of the U.S. National Seismic Hazard Maps

USGS Publications Warehouse

Frankel, Arthur; Chen, Rui; Petersen, Mark; Moschetti, Morgan P.; Sherrod, Brian

2015-01-01

Several aspects of the earthquake characterization were changed for the Pacific Northwest portion of the 2014 update of the national seismic hazard maps, reflecting recent scientific findings. New logic trees were developed for the recurrence parameters of M8-9 earthquakes on the Cascadia subduction zone (CSZ) and for the eastern edge of their rupture zones. These logic trees reflect recent findings of additional M8 CSZ earthquakes using offshore deposits of turbidity flows and onshore tsunami deposits and subsidence. These M8 earthquakes each rupture a portion of the CSZ and occur in the time periods between M9 earthquakes that have an average recurrence interval of about 500 years. The maximum magnitude was increased for deep intraslab earthquakes. An areal source zone to account for the possibility of deep earthquakes under western Oregon was expanded. The western portion of the Tacoma fault was added to the hazard maps.

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.

Tsunami vulnerability and damage assessment in the coastal area of Rabat and Salé, Morocco

NASA Astrophysics Data System (ADS)

Atillah, A.; El Hadani, D.; Moudni, H.; Lesne, O.; Renou, C.; Mangin, A.; Rouffi, F.

2011-12-01

This study, a companion paper to Renou et al. (2011), focuses on the application of a GIS-based method to assess building vulnerability and damage in the event of a tsunami affecting the coastal area of Rabat and Salé, Morocco. This approach, designed within the framework of the European SCHEMA project (www.schemaproject.org) is based on the combination of hazard results from numerical modelling of the worst case tsunami scenario (inundation depth) based on the historical Lisbon earthquake of 1755 and the Portugal earthquake of 1969, together with vulnerability building types derived from Earth Observation data, field surveys and GIS data. The risk is then evaluated for this highly concentrated population area characterized by the implementation of a vast project of residential and touristic buildings within the flat area of the Bouregreg Valley separating the cities of Rabat and Salé. A GIS tool is used to derive building damage maps by crossing layers of inundation levels and building vulnerability. The inferred damage maps serve as a base for elaborating evacuation plans with appropriate rescue and relief processes and to prepare and consider appropriate measures to prevent the induced tsunami risk.

Developing a global tsunami propagation database and its application for coastal hazard assessments in China

NASA Astrophysics Data System (ADS)

Wang, N.; Tang, L.; Titov, V.; Newman, J. C.; Dong, S.; Wei, Y.

2013-12-01

The tragedies of the 2004 Indian Ocean and 2011 Japan tsunamis have increased awareness of tsunami hazards for many nations, including China. The low land level and high population density of China's coastal areas place it at high risk for tsunami hazards. Recent research (Komatsubara and Fujiwara, 2007) highlighted concerns of a magnitude 9.0 earthquake on the Nankai trench, which may affect China's coasts not only in South China Sea, but also in the East Sea and Yellow Sea. Here we present our work in progress towards developing a global tsunami propagation database that can be used for hazard assessments by many countries. The propagation scenarios are computed by using NOAA's MOST numerical model. Each scenario represents a typical Mw 7.5 earthquake with predefined earthquake parameters (Gica et al., 2008). The model grid was interpolated from ETOPO1 at 4 arc-min resolution, covering -80° to72°N and 0 to 360°E. We use this database for preliminary tsunami hazard assessment along China's coastlines.

Research on the Improvements of the Assembly Areas, Evacuation Routes, and Shelters against Multiple Disasters

NASA Astrophysics Data System (ADS)

Jin, S.; Lee, Y. M.; Jeong, S. Y.; Hong, S. J.

2016-12-01

The considerable casualties were resulted at the tsunami shelters during the Great East Japan Tsunami on 11 March 2011. The one of the important lessons learned from the Great East Japan Tsunami and the Fukushima NPP accidents provided the nuclear power plant emergency plan should consider the natural disaster. However, most of cases, the nuclear emergency preparedness strategies have not incorporated the natural disaster management plan. In this study, we reviewed the safety of the assembly areas, evacuation routes, and shelters of some nuclear emergency planning zone using the new tsunami hazard mapping results through the characteristic inundation analysis. As the result of this study, the improvements can be achieved by considering both natural and nuclear disaster to set up the assembly areas, evacuation routes, and shelters against the multiple disasters. Also, The most important protective measures can be achieved by integrating and linking the emergency preparedness strategy both natural disasters and nuclear disaster in the future.

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.

Tsunami hazard assessment in the Hudson River Estuary based on dynamic tsunami-tide simulations

NASA Astrophysics Data System (ADS)

Shelby, Michael; Grilli, Stéphan T.; Grilli, Annette R.

2016-12-01

This work is part of a tsunami inundation mapping activity carried out along the US East Coast since 2010, under the auspice of the National Tsunami Hazard Mitigation program (NTHMP). The US East Coast features two main estuaries with significant tidal forcing, which are bordered by numerous critical facilities (power plants, major harbors,...) as well as densely built low-level areas: Chesapeake Bay and the Hudson River Estuary (HRE). HRE is the object of this work, with specific focus on assessing tsunami hazard in Manhattan, the Hudson and East River areas. In the NTHMP work, inundation maps are computed as envelopes of maximum surface elevation along the coast and inland, by simulating the impact of selected probable maximum tsunamis (PMT) in the Atlantic ocean margin and basin. At present, such simulations assume a static reference level near shore equal to the local mean high water (MHW) level. Here, instead we simulate maximum inundation in the HRE resulting from dynamic interactions between the incident PMTs and a tide, which is calibrated to achieve MHW at its maximum level. To identify conditions leading to maximum tsunami inundation, each PMT is simulated for four different phases of the tide and results are compared to those obtained for a static reference level. We first separately simulate the tide and the three PMTs that were found to be most significant for the HRE. These are caused by: (1) a flank collapse of the Cumbre Vieja Volcano (CVV) in the Canary Islands (with a 80 km3 volume representing the most likely extreme scenario); (2) an M9 coseismic source in the Puerto Rico Trench (PRT); and (3) a large submarine mass failure (SMF) in the Hudson River canyon of parameters similar to the 165 km3 historical Currituck slide, which is used as a local proxy for the maximum possible SMF. Simulations are performed with the nonlinear and dispersive long wave model FUNWAVE-TVD, in a series of nested grids of increasing resolution towards the coast, by one-way coupling. Four levels of nested grids are used, from a 1 arc-min spherical coordinate grid in the deep ocean down to a 39-m Cartesian grid in the HRE. Bottom friction coefficients in the finer grids are calibrated for the tide to achieve the local spatially averaged MHW level at high tide in the HRE. Combined tsunami-tide simulations are then performed for four phases of the tide corresponding to each tsunami arriving at Sandy Hook (NJ): 1.5 h ahead, concurrent with, 1.5 h after, and 3 h after the local high tide. These simulations are forced along the offshore boundary of the third-level grid by linearly superposing time series of surface elevation and horizontal currents of the calibrated tide and each tsunami wave train; this is done in deep enough water for a linear superposition to be accurate. Combined tsunami-tide simulations are then performed with FUNWAVE-TVD in this and the finest nested grids. Results show that, for the 3 PMTs, depending on the tide phase, the dynamic simulations lead to no or to a slightly increased inundation in the HRE (by up to 0.15 m depending on location), and to larger currents than for the simulations over a static level; the CRT SMF proxy tsunami is the PMT leading to maximum inundation in the HRE. For all tide phases, nonlinear interactions between tide and tsunami currents modify the elevation, current, and celerity of tsunami wave trains, mostly in the shallower water areas of the HRE where bottom friction dominates, as compared to a linear superposition of wave elevations and currents. We note that, while dynamic simulations predict a slight increase in inundation, this increase may be on the same order as, or even less than sources of uncertainty in the modeling of tsunami sources, such as their initial water elevation, and in bottom friction and bathymetry used in tsunami grids. Nevertheless, results in this paper provide insight into the magnitude and spatial variability of tsunami propagation and impact in the complex inland waterways surrounding New York City, and of their modification by dynamic tidal effects. We conclude that changes in inundation resulting from the inclusion of a dynamic tide in the specific case of the HRE, although of scientific interest, are not significant for tsunami hazard assessment and that the standard approach of specifying a static reference level equal to MHW is conservative. However, in other estuaries with similarly complex bathymetry/topography and stronger tidal currents, a simplified static approach might not be appropriate.

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.

Comparing the Performance of Japan's Earthquake Hazard Maps to Uniform and Randomized Maps

NASA Astrophysics Data System (ADS)

Brooks, E. M.; Stein, S. A.; Spencer, B. D.

2015-12-01

The devastating 2011 magnitude 9.1 Tohoku earthquake and the resulting shaking and tsunami were much larger than anticipated in earthquake hazard maps. Because this and all other earthquakes that caused ten or more fatalities in Japan since 1979 occurred in places assigned a relatively low hazard, Geller (2011) argued that "all of Japan is at risk from earthquakes, and the present state of seismological science does not allow us to reliably differentiate the risk level in particular geographic areas," so a map showing uniform hazard would be preferable to the existing map. Defenders of the maps countered by arguing that these earthquakes are low-probability events allowed by the maps, which predict the levels of shaking that should expected with a certain probability over a given time. Although such maps are used worldwide in making costly policy decisions for earthquake-resistant construction, how well these maps actually perform is unknown. We explore this hotly-contested issue by comparing how well a 510-year-long record of earthquake shaking in Japan is described by the Japanese national hazard (JNH) maps, uniform maps, and randomized maps. Surprisingly, as measured by the metric implicit in the JNH maps, i.e. that during the chosen time interval the predicted ground motion should be exceeded only at a specific fraction of the sites, both uniform and randomized maps do better than the actual maps. However, using as a metric the squared misfit between maximum observed shaking and that predicted, the JNH maps do better than uniform or randomized maps. These results indicate that the JNH maps are not performing as well as expected, that what factors control map performance is complicated, and that learning more about how maps perform and why would be valuable in making more effective policy.

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.

Overview of the U.S. Nuclear Regulatory Commission collaborative research program to assess tsunami hazard for nuclear power plants on the Atlantic and Gulf Coasts

USGS Publications Warehouse

Kammerer, A.M.; ten Brink, Uri S.; Titov, V.V.

2017-01-01

In response to the 2004 Indian Ocean Tsunami, the United States Nuclear Regulatory Commission (US NRC) initiated a long-term research program to improve understanding of tsunami hazard levels for nuclear facilities in the United States. For this effort, the US NRC organized a collaborative research program with the United States Geological Survey (USGS) and the National Oceanic and Atmospheric Administration (NOAA) with a goal of assessing tsunami hazard on the Atlantic and Gulf Coasts of the United States. Necessarily, the US NRC research program includes both seismic- and landslide-based tsunamigenic sources in both the near and the far fields. The inclusion of tsunamigenic landslides, an important category of sources that impact tsunami hazard levels for the Atlantic and Gulf Coasts is a key difference between this program and most other tsunami hazard assessment programs. The initial phase of this work consisted of collection, interpretation, and analysis of available offshore data, with significant effort focused on characterizing offshore near-field landslides and analyzing their tsunamigenic potential and properties. In the next phase of research, additional field investigations will be conducted in key locations of interest and additional analysis will be undertaken. Simultaneously, the MOST tsunami generation and propagation model used by NOAA will first be enhanced to include landslide-based initiation mechanisms and then will be used to investigate the impact of the tsunamigenic sources identified and characterized by the USGS. The potential for probabilistic tsunami hazard assessment will also be explore in the final phases of the program.

A tribute to George Plafker

USGS Publications Warehouse

Fuis, Gary S.; Haeussler, Peter J.; Atwater, Brian F.

2015-01-01

In a long and distinguished career, George Plafker made fundamental advances in understanding of megathrust tectonics, tsunami generation, paleoseismology, crustal neotectonics, and Alaskan geology, chiefly by means of geological field observations. George discovered that giant earthquakes result from tens of meters of seismic slip on subduction megathrusts, and he did this before the theory of plate tectonics had become a paradigm. The discovery was founded on George's comprehensive mapping of land-level changes in the aftermath of the 1964 earthquake in Alaska, and on his follow-up mapping, in 1968, in the region of the 1960 earthquakes in Chile. The mapping showed paired, parallel belts of coseismic uplift largely offshore and coseismic subsidence mostly onshore – a pattern now familiar as the initial condition assumed in simulations of subduction-zone tsunamis. George recognized, moreover, that splay faulting can play a major role in tsunami generation, and he also distinguished carefully between tectonic and landslide sources for the multiple tsunamis that accounted for nearly all the fatalities associated with the 1964 Alaska earthquake. George's classic monographs on the 1964 earthquake include findings on subduction-zone paleoseismology that he soon extended to include stratigraphic evidence for cyclic vertical deformation at the Copper River Delta, as well as recurrent uplift evidenced by flights of marine terraces at Middleton Island. As a geologist of earthquakes, George also clarified the tectonics and hazards of crustal faulting in Alaska, California, and other areas worldwide. All the while, George was mapping bedrock geology in Alaska, where he contributed importantly to today's understanding of how terranes were accreted and modified. Especially important was his documentation of the origin, movement, subduction, and collision of the Yakutat terrane in southern Alaska.

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.

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).

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.

Probabilistic tsunami hazard assessment for the Makran region with focus on maximum magnitude assumption

NASA Astrophysics Data System (ADS)

Hoechner, Andreas; Babeyko, Andrey Y.; Zamora, Natalia

2016-06-01

Despite having been rather seismically quiescent for the last decades, the Makran subduction zone is capable of hosting destructive earthquakes and tsunami. In particular, the well-known thrust event in 1945 (Balochistan earthquake) led to about 4000 casualties. Nowadays, the coastal regions are more densely populated and vulnerable to similar events. Furthermore, some recent publications discuss rare but significantly larger events at the Makran subduction zone as possible scenarios. We analyze the instrumental and historical seismicity at the subduction plate interface and generate various synthetic earthquake catalogs spanning 300 000 years with varying magnitude-frequency relations. For every event in the catalogs we compute estimated tsunami heights and present the resulting tsunami hazard along the coasts of Pakistan, Iran and Oman in the form of probabilistic tsunami hazard curves. We show how the hazard results depend on variation of the Gutenberg-Richter parameters and especially maximum magnitude assumption.

Probabilistic tsunami hazard assessment for the Makran region with focus on maximum magnitude assumption

NASA Astrophysics Data System (ADS)

Hoechner, A.; Babeyko, A. Y.; Zamora, N.

2015-09-01

Despite having been rather seismically quiescent for the last decades, the Makran subduction zone is capable of hosting destructive earthquakes and tsunami. In particular, the well-known thrust event in 1945 (Balochistan earthquake) led to about 4000 casualties. Nowadays, the coastal regions are more densely populated and vulnerable to similar events. Furthermore, some recent publications discuss rare but significantly larger events at the Makran subduction zone as possible scenarios. We analyze the instrumental and historical seismicity at the subduction plate interface and generate various synthetic earthquake catalogs spanning 300 000 years with varying magnitude-frequency relations. For every event in the catalogs we compute estimated tsunami heights and present the resulting tsunami hazard along the coasts of Pakistan, Iran and Oman in the form of probabilistic tsunami hazard curves. We show how the hazard results depend on variation of the Gutenberg-Richter parameters and especially maximum magnitude assumption.

Preliminary results of the U.S. Nuclear Regulatory Commission collaborative research program to assess tsunami hazard for nuclear power plants on the Atlantic and gulf coasts

USGS Publications Warehouse

Kammerer, A.M.; ten Brink, Uri S.; Twitchell, David C.; Geist, Eric L.; Chaytor, Jason D.; Locat, J.; Lee, H.J.; Buczkowski, Brian J.; Sansoucy, M.

2008-01-01

In response to the 2004 Indian Ocean Tsunami, the United States Nuclear Regulatory Commission (US NRC) initiated a long-term research program to improve understanding of tsunami hazard levels for nuclear facilities in the United States. For this effort, the US NRC organized a collaborative research program with the United States Geological Survey (USGS) and other key researchers for the purpose of assessing tsunami hazard on the Atlantic and Gulf Coasts of the United States. The initial phase of this work consisted principally of collection, interpretation, and analysis of available offshore data and information. Necessarily, the US NRC research program includes both seismic- and landslide-based tsunamigenic sources in both the near and the far fields. The inclusion of tsunamigenic landslides, an important category of sources that impact tsunami hazard levels for the Atlantic and Gulf Coasts over the long time periods of interest to the US NRC is a key difference between this program and most other tsunami hazard assessment programs. Although only a few years old, this program is already producing results that both support current US NRC activities and look toward the long-term goal of probabilistic tsunami hazard assessment. This paper provides a summary of results from several areas of current research. An overview of the broader US NRC research program is provided in a companion paper in this conference.

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.

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/

Empirical Fragility Analysis of Buildings and Boats Damaged By the 2011 Great East Japan Tsunami and Their Practical Application

NASA Astrophysics Data System (ADS)

Suppasri, A.; Charvet, I.; Leelawat, N.; Fukutani, Y.; Muhari, A.; Futami, T.; Imamura, F.

2014-12-01

This study focused in turn on detailed data of buildings and boats damage caused by the 2011 tsunami in order to understand its main causes and provide damage probability estimates. Tsunami-induced building damage data was collected from field surveys, and includes inundation depth, building material, number of stories and occupancy type for more than 80,000 buildings. Numerical simulations with high resolution bathymetry and topography data were conducted to obtain characteristic tsunami measures such as flow velocity. These data were analyzed using advanced statistical methods, ordinal regression analysis to create not only empirical 2D tsunami fragility curves, but also 3D tsunami fragility surfaces for the first time. The effect of floating debris was also considered, by using a binary indicator of debris impact based on the proximity of a structure from a debris source (i.e. washed away building). Both the 2D and 3D fragility analyses provided results for each different building damage level, and different topography. While 2D fragility curves provide easily interpretable results relating tsunami flow depth to damage probability for different damage levels, 3D fragility surfaces allow for several influential tsunami parameters to be taken into account thus reduce uncertainty in the probability estimations. More than 20,000 damaged boats were used in the analysis similar to the one carried out on the buildings. Detailed data for each boat comprises information on the damage ratio (paid value over insured value), tonnage, engine type, material type and damage classification. The 2D and 3D fragility analyses were developed using representative tsunami heights for each port obtained from field surveys and flow velocities obtained from the aforementioned simulations. The results are currently being adapted for practical disaster mitigation. They are being integrated with the probabilistic tsunami hazard analysis, in order to create offshore and onshore probabilistic hazard maps. Through the GPS and embedded calculation function based on the aforementioned fragility results, these applications can be used in the field for a quick estimation of possible building damage, as well as a decision support system for fishermen (whether or not they should move their boats to the deep sea upon tsunami arrival).

Web-based Tsunami Early Warning System with instant Tsunami Propagation Calculations in the GPU Cloud

NASA Astrophysics Data System (ADS)

Hammitzsch, M.; Spazier, J.; Reißland, S.

2014-12-01

Usually, tsunami early warning and mitigation systems (TWS or TEWS) are based on several software components deployed in a client-server based infrastructure. The vast majority of systems importantly include desktop-based clients with a graphical user interface (GUI) for the operators in early warning centers. However, in times of cloud computing and ubiquitous computing the use of concepts and paradigms, introduced by continuously evolving approaches in information and communications technology (ICT), have to be considered even for early warning systems (EWS). Based on the experiences and the knowledge gained in three research projects - 'German Indonesian Tsunami Early Warning System' (GITEWS), 'Distant Early Warning System' (DEWS), and 'Collaborative, Complex, and Critical Decision-Support in Evolving Crises' (TRIDEC) - new technologies are exploited to implement a cloud-based and web-based prototype to open up new prospects for EWS. This prototype, named 'TRIDEC Cloud', merges several complementary external and in-house cloud-based services into one platform for automated background computation with graphics processing units (GPU), for web-mapping of hazard specific geospatial data, and for serving relevant functionality to handle, share, and communicate threat specific information in a collaborative and distributed environment. The prototype in its current version addresses tsunami early warning and mitigation. The integration of GPU accelerated tsunami simulation computations have been an integral part of this prototype to foster early warning with on-demand tsunami predictions based on actual source parameters. However, the platform is meant for researchers around the world to make use of the cloud-based GPU computation to analyze other types of geohazards and natural hazards and react upon the computed situation picture with a web-based GUI in a web browser at remote sites. The current website is an early alpha version for demonstration purposes to give the concept a whirl and to shape science's future. Further functionality, improvements and possible profound changes have to implemented successively based on the users' evolving needs.

Tsunami hazard assessment in the Colombian Caribbean Coast with a deterministic approach

NASA Astrophysics Data System (ADS)

Otero Diaz, L.; Correa, R.; Ortiz R, J. C.; Restrepo L, J. C.

2014-12-01

For the Caribbean Sea, we propose six potential tectonic sources of tsunami, defining for each source the worst credible earthquake from the analysis of historical seismicity, tectonics, pasts tsunami, and review of IRIS, PDE, NOAA, and CMT catalogs. The generation and propagation of tsunami waves in the selected sources were simulated with COMCOT 1.7, which is a numerical model that solves the linear and nonlinear long wave equations in finite differences in both Cartesian, and spherical coordinates. The results of the modeling are presented in maps of maximum displacement of the free surface for the Colombian Caribbean coast and the island areas, and they show that the event would produce greater impact is generated in the source of North Panama Deformed Belt (NPDB), where the first wave train reaches the central Colombian coast in 40 minutes, generating wave heights up to 3.7 m. In San Andrés and Providencia island, tsunami waves reach more than 4.5 m due effects of edge waves caused by interactions between waves and a barrier coral reef around of each island. The results obtained in this work are useful for planning systems and future regional and local warning systems and to identify priority areas to conduct detailed research to the tsunami threat.

Helping coastal communities at risk from tsunamis: the role of U.S. Geological Survey research

USGS Publications Warehouse

Geist, Eric L.; Gelfenbaum, Guy R.; Jaffe, Bruce E.; Reid, Jane A.

2000-01-01

In 1946, 1960, and 1964, major tsunamis (giant sea waves usually caused by earthquakes or submarine landslides) struck coastal areas of the Pacific Ocean. In the U.S. alone, these tsunamis killed hundreds of people and caused many tens of millions of dollars in damage. Recent events in Papua New Guinea (1998) and elsewhere are reminders that a catastrophic tsunami could strike U.S. coasts at any time. The USGS, working closely with NOAA and other partners in the National Tsunami Hazard Mitigation Program, is helping to reduce losses from tsunamis through increased hazard assessment and improved real-time warning systems.

Errors in Seismic Hazard Assessment are Creating Huge Human Losses

NASA Astrophysics Data System (ADS)

Bela, J.

2015-12-01

The current practice of representing earthquake hazards to the public based upon their perceived likelihood or probability of occurrence is proven now by the global record of actual earthquakes to be not only erroneous and unreliable, but also too deadly! Earthquake occurrence is sporadic and therefore assumptions of earthquake frequency and return-period are both not only misleading, but also categorically false. More than 700,000 people have now lost their lives (2000-2011), wherein 11 of the World's Deadliest Earthquakes have occurred in locations where probability-based seismic hazard assessments had predicted only low seismic low hazard. Unless seismic hazard assessment and the setting of minimum earthquake design safety standards for buildings and bridges are based on a more realistic deterministic recognition of "what can happen" rather than on what mathematical models suggest is "most likely to happen" such future huge human losses can only be expected to continue! The actual earthquake events that did occur were at or near the maximum potential-size event that either already had occurred in the past; or were geologically known to be possible. Haiti's M7 earthquake, 2010 (with > 222,000 fatalities) meant the dead could not even be buried with dignity. Japan's catastrophic Tohoku earthquake, 2011; a M9 Megathrust earthquake, unleashed a tsunami that not only obliterated coastal communities along the northern Japanese coast, but also claimed > 20,000 lives. This tsunami flooded nuclear reactors at Fukushima, causing 4 explosions and 3 reactors to melt down. But while this history of huge human losses due to erroneous and misleading seismic hazard estimates, despite its wrenching pain, cannot be unlived; if faced with courage and a more realistic deterministic estimate of "what is possible", it need not be lived again. An objective testing of the results of global probability based seismic hazard maps against real occurrences has never been done by the GSHAP team; even though the obvious inadequacy of the GSHAP map could have been established in the course of a simple check before the project completion. The doctrine of "psha exceptionalism" that created the maps can only be esponged by carefully examining the facts . . . which unfortunately include huge human losses!

Hazard proximity and risk perception of tsunamis in coastal cities: Are people able to identify their risk?

PubMed

Arias, Juan Pablo; Bronfman, Nicolás C; Cisternas, Pamela C; Repetto, Paula B

2017-01-01

Researchers have previously reported that hazard proximity can influence risk perception among individuals exposed to potential hazards. Understanding this relationship among coastline communities at risk of flood events caused by storms and/or tsunamis, is important because hazard proximity, should be recognized when planning and implementing preparation and mitigation actions against these events. Yet, we are not aware of studies that have examined this relationship among coastline inhabitants facing the risk of a tsunami. Consequently, the aim of this study was to examine the relationship between hazard proximity and perceived risk from tsunamis among coastline inhabitants. Participants were 487 residents of the coastal city of Iquique, Chile. They completed a survey during the spring of 2013 that assessed their perceived risk from several natural and non-natural hazards. We found that hazard proximity maintains a negative relationship with the perception of tsunami risk among coastline inhabitants. While this result confirms the general trend obtained in previous studies, this one is conclusive and significant. In contradiction with previous findings, we found that participants from the highest socioeconomic status reported the highest levels of risk perception. This finding can be explained by the fact that most participants from the highest socioeconomic status live closer to the coastline areas, so their risk perception reflects the place where they live, that is in a tsunami inundation zone. Once again, hazard proximity proved to be a determinant factor of risk perception. Our findings have important implications for the development of plans and programs for tsunami preparedness and mitigation. These indicate that individuals do use environmental cues to evaluate their own risk and can potentially make correct choices when having or not to evacuate. Also suggest that preparedness should incorporate how hazard proximity is recognized by individuals and communities at risk.

Hazard proximity and risk perception of tsunamis in coastal cities: Are people able to identify their risk?

PubMed Central

Arias, Juan Pablo; Bronfman, Nicolás C.; Cisternas, Pamela C.; Repetto, Paula B.

2017-01-01

Researchers have previously reported that hazard proximity can influence risk perception among individuals exposed to potential hazards. Understanding this relationship among coastline communities at risk of flood events caused by storms and/or tsunamis, is important because hazard proximity, should be recognized when planning and implementing preparation and mitigation actions against these events. Yet, we are not aware of studies that have examined this relationship among coastline inhabitants facing the risk of a tsunami. Consequently, the aim of this study was to examine the relationship between hazard proximity and perceived risk from tsunamis among coastline inhabitants. Participants were 487 residents of the coastal city of Iquique, Chile. They completed a survey during the spring of 2013 that assessed their perceived risk from several natural and non-natural hazards. We found that hazard proximity maintains a negative relationship with the perception of tsunami risk among coastline inhabitants. While this result confirms the general trend obtained in previous studies, this one is conclusive and significant. In contradiction with previous findings, we found that participants from the highest socioeconomic status reported the highest levels of risk perception. This finding can be explained by the fact that most participants from the highest socioeconomic status live closer to the coastline areas, so their risk perception reflects the place where they live, that is in a tsunami inundation zone. Once again, hazard proximity proved to be a determinant factor of risk perception. Our findings have important implications for the development of plans and programs for tsunami preparedness and mitigation. These indicate that individuals do use environmental cues to evaluate their own risk and can potentially make correct choices when having or not to evacuate. Also suggest that preparedness should incorporate how hazard proximity is recognized by individuals and communities at risk. PMID:29088230

The use of Near-surface Geophysics in Evaluating and Assessing Natural Hazards

NASA Astrophysics Data System (ADS)

Pellerin, L.

2007-12-01

The list of natural hazards that transform the physical environmental is extensive: earthquakes, tsunamis, floods, volcanoes, lahars, landslides and debris flows, avalanches, karst/cavern collapse, heavy-metal contamination, permafrost, liquefaction, and magnetic storms. Because these events or conditions can have significant negative impact on health and infrastructure, the need for knowledge about and education of natural hazards is important. Near-surface geophysics can contribute in significant ways to both the knowledge base and wider understanding of these hazards. The discipline encompasses a wide range of methodologies, some of which are described below. A post-tsunami helicopter electromagnetic (EM) survey along the coasts of Aceh, northern Sumatra was used to discriminate between fresh-water and saltwater aquifers., saltwater intrusion occurred close to the coast as a result of the tsunami and deep saltwater occurrences particularly around 30 m depth were mapped up to several kilometers inland. Based on the survey results recommendations were made to locate shallow hand-dug wells and medium depth (60m) water wells. Utilizing airborne EM and magnetic measurements, a detailed assessment of the internal distribution of altered zones within an active volcano; Mount Rainier (NW USA) showed that alteration is much more restricted than had been inferred from surficial exposures alone. The study also suggested that the collapse of fresh, unaltered portions of the volcano is possible, and no flank of the volcano can be considered immune from lahars during eruption. Ground penetrating radar (GPR) has been used worldwide in a variety of applications from geotechnical investigations related to geologic hazards. These include assessment of transportation infrastructure, which maybe be damaged due to a natural hazard, study of the movement of rock glaciers in the Swiss Alps, and search and recovery of avalanche victims. Permafrost is widespread in polar areas and cold mountain terrain. GPR, electrical resistivity and EM methods have been used successfully to map permafrost and massive ground ice. The stability of these materials has impact on building and development within these regions. Mass movements in lowland permafrost terrain, which have implications for climate change, are being monitoring with thermal borehole measurements. Whether in times of flood or draught, understanding our watersheds is an important use of near surface geophysics. Satellite-based remote sensing methods are used to efficiently obtain soil moisture measurements over large regions. Ground-based conductivity meters are used to map soil types that play a fundamental role affecting the pattern of stream flow response. Synthetic Aperture Radar (SAR) is used to directly measure surface deformation, which can be related to subsurface hydrological conditions, aseismic deformation or landslides. Resolution of fine as 2mm/year can be obtained from satellite-based measurements. This level of resolutions aids in seismic risk assessment and allows the extent of landslides to be mapped and monitored efficiently. A series of national probabilistic seismic shaking hazard maps are being produced by the US Geological Survey using gravity, magnetic and seismic data in addition to other information. They can be used as input for many policy decisions on building codes and land use, and to estimate the probabilities of strong earthquakes, detailed maps of shaking amplification and susceptibility to liquefaction and landslides, and planning scenarios of large urban earthquakes.

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

USGS Publications Warehouse

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

2017-01-01

Twenty-two papers on the study of tsunamis are included in Volume II 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 (Eds., E. L. Geist, H. M. Fritz, A. B. Rabinovich, and Y. Tanioka). Three papers in Volume II focus on details of the 2011 and 2016 tsunami-generating earthquakes offshore of Tohoku, Japan. The next six papers describe important case studies and observations of recent and historical events. Four papers related to tsunami hazard assessment are followed by three papers on tsunami hydrodynamics and numerical modelling. Three papers discuss problems of tsunami warning and real-time forecasting. The final set of three papers importantly investigates tsunamis generated by non-seismic sources: volcanic explosions, landslides, and meteorological disturbances. Collectively, this volume highlights contemporary trends in global tsunami research, both fundamental and applied toward hazard assessment and mitigation.

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).

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

NASA Astrophysics Data System (ADS)

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

2017-08-01

Twenty-two papers on the study of tsunamis are included in Volume II 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 (Eds., E. L. Geist, H. M. Fritz, A. B. Rabinovich, and Y. Tanioka). Three papers in Volume II focus on details of the 2011 and 2016 tsunami-generating earthquakes offshore of Tohoku, Japan. The next six papers describe important case studies and observations of recent and historical events. Four papers related to tsunami hazard assessment are followed by three papers on tsunami hydrodynamics and numerical modelling. Three papers discuss problems of tsunami warning and real-time forecasting. The final set of three papers importantly investigates tsunamis generated by non-seismic sources: volcanic explosions, landslides, and meteorological disturbances. Collectively, this volume highlights contemporary trends in global tsunami research, both fundamental and applied toward hazard assessment and mitigation.

A Comprehensive Probabilistic Tsunami Hazard Assessment: Multiple Sources and Short-Term Interactions

NASA Astrophysics Data System (ADS)

Anita, G.; Selva, J.; Laura, S.

2011-12-01

We develop a comprehensive and total probabilistic tsunami hazard assessment (TotPTHA), in which many different possible source types concur to the definition of the total tsunami hazard at given target sites. In a multi-hazard and multi-risk perspective, such an innovative approach allows, in principle, to consider all possible tsunamigenic sources, from seismic events, to slides, asteroids, volcanic eruptions, etc. In this respect, we also formally introduce and discuss the treatment of interaction/cascade effects in the TotPTHA analysis. We demonstrate how external triggering events may induce significant temporary variations in the tsunami hazard. Because of this, such effects should always be considered, at least in short-term applications, to obtain unbiased analyses. Finally, we prove the feasibility of the TotPTHA and of the treatment of interaction/cascade effects by applying this methodology to an ideal region with realistic characteristics (Neverland).

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.

Inter-model analysis of tsunami-induced coastal currents

NASA Astrophysics Data System (ADS)

Lynett, Patrick J.; Gately, Kara; Wilson, Rick; Montoya, Luis; Arcas, Diego; Aytore, Betul; Bai, Yefei; Bricker, Jeremy D.; Castro, Manuel J.; Cheung, Kwok Fai; David, C. Gabriel; Dogan, Gozde Guney; Escalante, Cipriano; González-Vida, José Manuel; Grilli, Stephan T.; Heitmann, Troy W.; Horrillo, Juan; Kânoğlu, Utku; Kian, Rozita; Kirby, James T.; Li, Wenwen; Macías, Jorge; Nicolsky, Dmitry J.; Ortega, Sergio; Pampell-Manis, Alyssa; Park, Yong Sung; Roeber, Volker; Sharghivand, Naeimeh; Shelby, Michael; Shi, Fengyan; Tehranirad, Babak; Tolkova, Elena; Thio, Hong Kie; Velioğlu, Deniz; Yalçıner, Ahmet Cevdet; Yamazaki, Yoshiki; Zaytsev, Andrey; Zhang, Y. J.

2017-06-01

To help produce accurate and consistent maritime hazard products, the National Tsunami Hazard Mitigation Program organized a benchmarking workshop to evaluate the numerical modeling of tsunami currents. Thirteen teams of international researchers, using a set of tsunami models currently utilized for hazard mitigation studies, presented results for a series of benchmarking problems; these results are summarized in this paper. Comparisons focus on physical situations where the currents are shear and separation driven, and are thus de-coupled from the incident tsunami waveform. In general, we find that models of increasing physical complexity provide better accuracy, and that low-order three-dimensional models are superior to high-order two-dimensional models. Inside separation zones and in areas strongly affected by eddies, the magnitude of both model-data errors and inter-model differences can be the same as the magnitude of the mean flow. Thus, we make arguments for the need of an ensemble modeling approach for areas affected by large-scale turbulent eddies, where deterministic simulation may be misleading. As a result of the analyses presented herein, we expect that tsunami modelers now have a better awareness of their ability to accurately capture the physics of tsunami currents, and therefore a better understanding of how to use these simulation tools for hazard assessment and mitigation efforts.

Assessing tsunami vulnerability, an example from Herakleio, Crete

NASA Astrophysics Data System (ADS)

Papathoma, M.; Dominey-Howes, D.; Zong, Y.; Smith, D.

Recent tsunami have caused massive loss of life, destruction of coastal infrastructures and disruption to economic activity. To date, tsunami hazard studies have concentrated on determining the frequency and magnitude of events and in the production of simplistic flood maps. In general, such maps appear to have assumed a uniform vulnerability of population, infrastructure and business. In reality however, a complex set of factors interact to produce a pattern of vulnerability that varies spatially and temporally. A new vulnerability assessment approach is described, that incorporates multiple factors (e.g. parameters relating to the natural and built environments and socio-demographics) that contribute to tsunami vulnerability. The new methodology is applied on a coastal segment in Greece and, in particular, in Crete, westof the city of Herakleio. The results are presented within a Geographic Information System (GIS). The application of GIS ensures the approach is novel for tsunami studies, since it permits interrogation of the primary database by several different end-users. For example, the GIS may be used: (1) to determine immediate post-tsunami disaster response needs by the emergency services; (2) to preplan tsunami mitigation measures by disaster planners; (3) as a tool for local planning by the municipal authorities or; (4) as a basis for catastrophe modelling by insurance companies. We show that population density varies markedly with the time of the year and that 30% of buildings within the inundation zone are only single story thus increasing the vulnerability of their occupants. Within the high inundation depth zone, 11% of buildings are identified as in need of reinforcement and this figure rises to 50% within the medium inundation depth zone. 10% of businesses are located within the high inundation depth zone and these may need to consider their level of insurance cover to protect against primary building damage, contents loss and business interruption losses.

Geographical Information Analysis of Tsunami Flooded Area by the Great East Japan Earthquake Using Mobile Mapping System

NASA Astrophysics Data System (ADS)

Koarai, M.; Okatani, T.; Nakano, T.; Nakamura, T.; Hasegawa, M.

2012-07-01

The great earthquake occurred in Tohoku District, Japan on 11th March, 2011. This earthquake is named "the 2011 off the Pacific coast of Tohoku Earthquake", and the damage by this earthquake is named "the Great East Japan Earthquake". About twenty thousand people were killed or lost by the tsunami of this earthquake, and large area was flooded and a large number of buildings were destroyed by the tsunami. The Geospatial Information Authority of Japan (GSI) has provided the data of tsunami flooded area interpreted from aerial photos taken just after the great earthquake. This is fundamental data of tsunami damage and very useful for consideration of reconstruction planning of tsunami damaged area. The authors analyzed the relationship among land use, landform classification, DEMs data flooded depth of the tsunami flooded area by the Great East Japan Earthquake in the Sendai Plain using GIS. Land use data is 100 meter grid data of National Land Information Data by the Ministry of Land, Infrastructure, Transportation and Tourism (MLIT). Landform classification data is vector data of Land Condition Map produced by GSI. DEMs data are 5 meters grid data measured with LiDAR by GSI after earthquake. Especially, the authors noticed the relationship between tsunami hazard damage and flooded depth. The authors divided tsunami damage into three categories by interpreting aerial photos; first is the completely destroyed area where almost wooden buildings were lost, second is the heavily damaged area where a large number of houses were destroyed by the tsunami, and third is the flooded only area where houses were less destroyed. The flooded depth was measured by photogrammetric method using digital image taken by Mobile Mapping System (MMS). The result of these geographic analyses show the distribution of tsunami damage level is as follows: 1) The completely destroyed area was located within 1km area from the coastline, flooded depth of this area is over 4m, and no relationship between damaged area and landform classification. 2) The heavily damaged area was observed up to 3 or 4km from the coastline. Flooded depth of this area is over 1.5m, and there is a good relationship between damaged area and height of DEMs. 3) The flood only area was observed up to 4 or 5km from the coastline. Flooded depth of this area was less than 1.5m, and there is a good relationship between damaged area and landform. For instance, a certain area in valley plain or flooded plain was not affected by the tsunami, even though an area with almost the same height in coastal plain or delta was flooded. These results mean that it is important for tsunami disaster management to consider not only DEMs but also landform classification.

Integrated approach for coastal hazards and risks in Sri Lanka

NASA Astrophysics Data System (ADS)

Garcin, M.; Desprats, J. F.; Fontaine, M.; Pedreros, R.; Attanayake, N.; Fernando, S.; Siriwardana, C. H. E. R.; de Silva, U.; Poisson, B.

2008-06-01

The devastating impact of the tsunami of 26 December 2004 on the shores of the Indian Ocean recalled the importance of knowledge and the taking into account of coastal hazards. Sri Lanka was one of the countries most affected by this tsunami (e.g. 30 000 dead, 1 million people homeless and 70% of the fishing fleet destroyed). Following this tsunami, as part of the French post-tsunami aid, a project to establish a Geographical Information System (GIS) on coastal hazards and risks was funded. This project aims to define, at a pilot site, a methodology for multiple coastal hazards assessment that might be useful for the post-tsunami reconstruction and for development planning. This methodology could be applied to the whole coastline of Sri Lanka. The multi-hazard approach deals with very different coastal processes in terms of dynamics as well as in terms of return period. The first elements of this study are presented here. We used a set of tools integrating a GIS, numerical simulations and risk scenario modelling. While this action occurred in response to the crisis caused by the tsunami, it was decided to integrate other coastal hazards into the study. Although less dramatic than the tsunami these remain responsible for loss of life and damage. Furthermore, the establishment of such a system could not ignore the longer-term effects of climate change on coastal hazards in Sri Lanka. This GIS integrates the physical and demographic data available in Sri Lanka that is useful for assessing the coastal hazards and risks. In addition, these data have been used in numerical modelling of the waves generated during periods of monsoon as well as for the December 2004 tsunami. Risk scenarios have also been assessed for test areas and validated by field data acquired during the project. The results obtained from the models can be further integrated into the GIS and contribute to its enrichment and to help in better assessment and mitigation of these risks. The coastal-hazards-and-risks GIS coupled with modelling thus appears to be a very useful tool that can constitute the skeleton of a coastal zone management system. Decision makers will be able to make informed choices with regards to hazards during reconstruction and urban planning projects.

New contributions to the debate on the cause of the January 11th, 1693 tsunami in eastern Sicily (Italy): earthquake or offshore landslide source (or may be both)?

NASA Astrophysics Data System (ADS)

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

2007-12-01

Eastern Sicily is among the most exposed regions in Italy and in the whole Mediterranean to tsunami hazard and risk. The historical tsunamis recorded here were generally associated to moderate-to-large magnitude earthquakes. The largest tsunami documented in the area occurred on January 11th, 1693. It followed the highest-magnitude earthquake (7.4) of the Italian seismic history. The tsunami, whose first significant motion was a retreat along the entire eastern Sicily coastline, produced the most devastating effects at Augusta (15 meters run-up) and Catania, being relevant at Siracusa and Messina too. A lively debate exists on whether the earthquake was the only source of the tsunami, or other causes (such as submarine landslides, possibly triggered by the earthquake) contributed to the tsunami generation. In the framework of the EC funded project TRANSFER, we investigate both hypotheses, starting from suitable onshore and offshore faults as well as from offshore landslide bodies, and hence simulating numerically the ensuing tsunami and comparing the results with the available historical information. We base on the results obtained during recent offshore surveys, in particular the multichannel seismic survey MESC2001, carried out in year 2001 on board the R/V Urania of the Italian National Council of Researches (CNR), which mapped both active normal faults and a number of possible landslide bodies along the Hyblaean-Malta escarpment, the most prominent tectonic structure found just few kilometres offshore eastern Sicily. From the modelling point of view, the initial condition for the earthquake- generated tsunamis coincides with the vertical coseismic deformation of the seafloor. Instead, the landslide motion is simulated through the Lagrangian block model UBO-BLOCK2, developed at the University of Bologna. Finally, the finite-element code UBO-TSUFE, implemented by the same research team, is used to simulate the tsunami generation and propagation. The main conclusions are: 1) if the earthquake is postulated to be the only responsible for the tsunami, then the historical information can be reproduced only by assuming an offshore tectonic source; 2) taking into account the largest of the mapped landslides, we are able to reproduce quite satisfactorily both the first polarity and the size distribution of the tsunami; 3) we cannot rule out the idea that there was a concurrent contribution of the earthquake and of the landslide in generating the tsunami.

Towards a probabilistic tsunami hazard analysis for the Gulf of Cadiz

NASA Astrophysics Data System (ADS)

Løvholt, Finn; Urgeles, Roger

2017-04-01

Landslides and volcanic flank collapses constitute a significant portion of all known tsunami sources, and they are less constrained geographically than earthquakes as they are not tied to large fault zones. While landslides have mostly produced local tsunamis historically, prehistoric evidence show that landslides can also produce ocean wide tsunamis. Because the landslide induced tsunami probability is more difficult to quantify than the one induced by earthquakes, our understanding of the landslide tsunami hazard is less understood. To improve our understanding and methodologies to deal with this hazard, we here present results and methods for a preliminary landslide probabilistic tsunami hazard assessment (LPTHA) for the Gulf of Cadiz for submerged landslides. The present literature on LPTHA is sparse, and studies have so far been separated into two groups, the first based on observed magnitude frequency distributions (MFD's), the second based on simplified geotechnical slope stability analysis. We argue that the MFD based approach is best suited when a sufficient amount of data covering a wide range of volumes is available, although uncertainties in the dating of the landslides often represent a potential large source of bias. To this end, the relatively rich availability of landslide data in the Gulf of Cadiz makes this area suitable for developing and testing LPTHA models. In the presentation, we will first explore the landslide data and statistics, including different spatial factors such as slope versus volume relationships, faults etc. Examples of how random realizations can be used to distribute tsunami source over the study area will be demonstrated. Furthermore, computational strategies for simulating both the landslide and the tsunami generation in a simplified way will be described. To this end, we use depth averaged viscoplastic landslide model coupled to the numerical tsunami model to represent a set of idealized tsunami sources, which are in turn put into a regional tsunami model for computing the tsunami propagation. We devote attention to discussing the epistemic uncertainty and sensitivity of the landslide input parameters, and how these may affect the hazard assessment. As the full variability of the landslide parameters cannot be endured, we show that there is a considerable challenge related to the multiple landslide parameter variability. Finally, we discuss some logical next steps in the analysis, as well as possible sources of error.

Scenario-Based Tsunami Hazard Assessment from Earthquake and Landslide Sources for Eastern Sicily, Italy

NASA Astrophysics Data System (ADS)

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

2016-12-01

Eastern Sicily was theatre of the most damaging tsunamis that ever struck Italy, such as the 11 January 1693 and the 28 December 1908 tsunamis. Tectonic studies and paleotsunami investigations extended historical records of tsunami occurrence back of several thousands of years. Tsunami sources relevant for eastern Sicily are both local and remote, the latter being located in the Ionian Greece and in the Western Hellenic Arc. Here in 365 A.D. a large earthquake generated a tsunami that was seen in the whole eastern and central Mediterranean including the Sicilian coasts. The objective of this study is the evaluation of tsunami hazard along the coast of eastern Sicily, central Mediterranean, Italy via a scenario-based technique, which has been preferred to the PTHA approach because, when dealing with tsunamis induced by landslides, uncertainties are usually so large to undermine the PTHA results. Tsunamis of earthquake and landslide origin are taken into account for the entire coast of Sicily, from the Messina to the Siracusa provinces. Landslides are essentially local sources and can occur underwater along the unstable flanks of the Messina Straits or along the steep slopes of the Hyblaean-Malta escarpment. The method is based on a two-step procedure. After a preliminary step where very many earthquake and landslide sources are taken into account and tsunamis are computed on a low-resolution grid, the worst-case scenarios are selected and tsunamis are simulated on a finer-resolution grid allowing for a better calculation of coastal wave height and tsunami penetration. The final result of our study is given in the form of aggregate fields computed from individual scenarios. Also interesting is the contribution of the various tsunami sources in different localities along the coast. It is found that the places with the highest level of hazard are the low lands of La Playa south of Catania and of the Bay of Augusta, which is in agreement also with historical observations. It is further found that remote seismic sources from the Hellenic Arc are the dominant factor of hazard in several places, and that, though in general earthquakes contribute to hazard more than landslides, in some places the opposite is true.

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.

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.

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.

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.

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

Steps Towards the Implementation of a Tsunami Detection, Warning, Mitigation and Preparedness Program for Southwestern Coastal Areas of Mexico

NASA Astrophysics Data System (ADS)

Farreras, Salvador; Ortiz, Modesto; Gonzalez, Juan I.

2007-03-01

The highly vulnerable Pacific southwest coast of Mexico has been repeatedly affected by local, regional and remote source tsunamis. Mexico presently has no national tsunami warning system in operation. The implementation of key elements of a National Program on Tsunami Detection, Monitoring, Warning and Mitigation is in progress. For local and regional events detection and monitoring, a prototype of a robust and low cost high frequency sea-level tsunami gauge, sampling every minute and equipped with 24 hours real time transmission to the Internet, was developed and is currently in operation. Statistics allow identification of low, medium and extreme hazard categories of arriving tsunamis. These categories are used as prototypes for computer simulations of coastal flooding. A finite-difference numerical model with linear wave theory for the deep ocean propagation, and shallow water nonlinear one for the near shore and interaction with the coast, and non-fixed boundaries for flooding and recession at the coast, is used. For prevention purposes, tsunami inundation maps for several coastal communities, are being produced in this way. The case of the heavily industrialized port of Lázaro Cárdenas, located on the sand shoals of a river delta, is illustrated; including a detailed vulnerability assessment study. For public education on preparedness and awareness, printed material for children and adults has been developed and published. It is intended to extend future coverage of this program to the Mexican Caribbean and Gulf of Mexico coastal areas.

Advances in the TRIDEC Cloud

NASA Astrophysics Data System (ADS)

Hammitzsch, Martin; Spazier, Johannes; Reißland, Sven

2016-04-01

The TRIDEC Cloud is a platform that merges several complementary cloud-based services for instant tsunami propagation calculations and automated background computation with graphics processing units (GPU), for web-mapping of hazard specific geospatial data, and for serving relevant functionality to handle, share, and communicate threat specific information in a collaborative and distributed environment. The platform offers a modern web-based graphical user interface so that operators in warning centres and stakeholders of other involved parties (e.g. CPAs, ministries) just need a standard web browser to access a full-fledged early warning and information system with unique interactive features such as Cloud Messages and Shared Maps. Furthermore, the TRIDEC Cloud can be accessed in different modes, e.g. the monitoring mode, which provides important functionality required to act in a real event, and the exercise-and-training mode, which enables training and exercises with virtual scenarios re-played by a scenario player. The software system architecture and open interfaces facilitate global coverage so that the system is applicable for any region in the world and allow the integration of different sensor systems as well as the integration of other hazard types and use cases different to tsunami early warning. Current advances of the TRIDEC Cloud platform will be summarized in this presentation.

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.

Tsunami Impact Computed from Offshore Modeling and Coastal Amplification Laws: Insights from the 2004 Indian Ocean Tsunami

NASA Astrophysics Data System (ADS)

Hébert, H.; Schindelé, F.

2015-12-01

The 2004 Indian Ocean tsunami gave the opportunity to gather unprecedented tsunami observation databases for various coastlines. We present here an analysis of such databases gathered for 3 coastlines, among the most impacted in 2004 in the intermediate- and far field: Thailand-Myanmar, SE India-Sri Lanka, and SE Madagascar. Non-linear shallow water tsunami modeling performed on a single 4' coarse bathymetric grid is compared to these observations, in order to check to which extent a simple approach based on the usual energy conservation laws (either Green's or Synolakis laws) can explain the data. The idea is to fit tsunami data with numerical modeling carried out without any refined coastal bathymetry/topography. To this end several parameters are discussed, namely the bathymetric depth to which model results must be extrapolated (using the Green's law), or the mean bathymetric slope to consider near the studied coast (when using the Synolakis law). Using extrapolation depths from 1 to 10 m generally allows a good fit; however, a 0.1 m is required for some others, especially in the far field (Madagascar) possibly due to enhanced numerical dispersion. Such a method also allows describing the tsunami impact variability along a given coastline. Then, using a series of scenarios, we propose a preliminary statistical assessment of tsunami impact for a given earthquake magnitude along the Indonesian subduction. Conversely, the sources mostly contributing to a specific hazard can also be mapped onto the sources, providing a first order definition of which sources are threatening the 3 studied coastlines.

Scenario Based Approach for Multiple Source Tsunami Hazard Assessment for Sines, Portugal

NASA Astrophysics Data System (ADS)

Wronna, Martin; Omira, Rachid; Baptista, Maria Ana

2015-04-01

In this paper, we present a scenario-based approach for tsunami hazard assessment for the city and harbour of Sines, Portugal one the test-sites of project ASTARTE. Sines holds one of the most important deep-water ports which contains oil-bearing, petrochemical, liquid bulk, coal and container terminals. The port and its industrial infrastructures are facing the ocean to the southwest facing the main seismogenic sources. This work considers two different seismic zones: the Southwest Iberian Margin and the Gloria Fault. Within these two regions, a total of five scenarios were selected to assess tsunami impact at the test site. These scenarios correspond to the worst-case credible scenario approach based upon the largest events of the historical and paleo tsunami catalogues. The tsunami simulations from the source area towards the coast is carried out using NSWING a Non-linear Shallow Water Model With Nested Grids. The code solves the non-linear shallow water equations using the discretization and explicit leap-frog finite difference scheme, in a Cartesian or Spherical frame. The initial sea surface displacement is assumed to be equal to the sea bottom deformation that is computed by Okada equations. Both uniform and non-uniform slip conditions are used. The presented results correspond to the models using non-uniform slip conditions. In this study, the static effect of tides is analysed for three different tidal stages MLLW (mean lower low water) MSL (mean sea level) and MHHW (mean higher high water). For each scenario, inundation is described by maximum values of wave height, flow depth, drawdown, run-up and inundation distance. Synthetic waveforms are computed at virtual tide gages at specific locations outside and inside the harbour. The final results consist of Aggregate Scenario Maps presented for the different inundation parameters. This work is funded by ASTARTE - Assessment, Strategy And Risk Reduction for Tsunamis in Europe - FP7-ENV2013 6.4-3, Grant 603839

Nationwide tsunami hazard assessment project in Japan

NASA Astrophysics Data System (ADS)

Hirata, K.; Fujiwara, H.; Nakamura, H.; Osada, M.; Ohsumi, T.; Morikawa, N.; Kawai, S.; Aoi, S.; Yamamoto, N.; Matsuyama, H.; Toyama, N.; Kito, T.; Murashima, Y.; Murata, Y.; Inoue, T.; Saito, R.; Akiyama, S.; Korenaga, M.; Abe, Y.; Hashimoto, N.

2014-12-01

In 2012, we began a project of nationwide Probabilistic Tsunami Hazard Assessment (PTHA) in Japan to support various measures (Fujiwara et al., 2013, JpGU; Hirata et al., 2014, AOGS). The most important strategy in the nationwide PTHA is predominance of aleatory uncertainty in the assessment but use of epistemic uncertainty is limited to the minimum, because the number of all possible combinations among epistemic uncertainties diverges quickly when the number of epistemic uncertainties in the assessment increases ; we consider only a type of earthquake occurrence probability distribution as epistemic uncertainty. We briefly show outlines of the nationwide PTHA as follows; (i) we consider all possible earthquakes in the future, including those that the Headquarters for Earthquake Research Promotion (HERP) of Japanese Government, already assessed. (ii) We construct a set of simplified earthquake fault models, called "Characterized Earthquake Fault Models (CEFMs)", for all of the earthquakes by following prescribed rules (Toyama et al., 2014, JpGU; Korenaga et al., 2014, JpGU). (iii) For all of initial water surface distributions caused by a number of the CEFMs, we calculate tsunamis by solving a nonlinear long wave equation, using FDM, including runup calculation, over a nesting grid system with a minimum grid size of 50 meters. (iv) Finally, we integrate information about the tsunamis calculated from the numerous CEFMs to get nationwide tsunami hazard assessments. One of the most popular representations of the integrated information is a tsunami hazard curve for coastal tsunami heights, incorporating uncertainties inherent in tsunami simulation and earthquake fault slip heterogeneity (Abe et al., 2014, JpGU). We will show a　PTHA along the eastern coast of Honshu, Japan, based on approximately 1,800 tsunami sources located within the subduction zone along the Japan Trench, as a prototype of the nationwide PTHA. This study is supported by part of the research project on research on evaluation of hazard and risk of natural disasters, under the direction of the HERP of Japanese Government.

From tsunami hazard assessment to risk management in Guadeloupe (F.W.I.)

NASA Astrophysics Data System (ADS)

Zahibo, Narcisse; Dudon, Bernard; Krien, Yann; Arnaud, Gaël; Mercado, Aurelio; Roger, Jean

2017-04-01

The Caribbean region is prone to numerous natural hazards such as earthquakes, landslides, storm surges, tsunamis, coastal erosion or hurricanes. All these threats may cause great human and economic losses and are thus of prime interest for applied research. One of the main challenges for the scientific community is to conduct state-of-the-art research to assess hazards and share the results with coastal planners and decision makers so that they can regulate land use and develop mitigation strategies. We present here the results of a scientific collaborative project between Guadeloupe and Porto Rico which aimed at bringing a decision-making support to the authorities regarding tsunami hazards. This project led us to build a database of potential extreme events, and to study their impacts on Guadeloupe to investigate storm surge and tsunami hazards. The results were used by local authorities to develop safeguarding and mitigation measures in coastal areas. This project is thus a good example to demonstrate the benefit of inter Caribbean scientific collaboration for natural risks management.

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.

Seismic and tsunami hazard investigation in Valparaiso in the framework of the project "MAR VASTO"

NASA Astrophysics Data System (ADS)

Romanelli, F.; Razafindrakoto, H.

2009-04-01

In the framework of the MAR VASTO Project ("Risk Management in Valparaíso/Manejo de Riesgos en Valparaíso"), completed in 2008 and funded by BID/IDB (Banco InterAmericano de Desarrollo/ InterAmerican Development Bank), managed by ENEA (Italian Agency for New Technologies, Energy and Environment), with the participation of Italian and Chilean partners and the support of local stakeholders, the most important hazards have been investigated carried out. Valparaíso represents a distinctive case of growth, inside a remarkable landscape, of an important Pacific Ocean seaport (over the 19th and 20th centuries), up to reaching a strategic importance in shipping trade, declined after the Panama Canal opening (1914). Thus, Valparaíso tells the never-ending story of a tight interaction between society and environment, stratifying different urban and architectonic layers, sometimes struck by disasters and always in danger. Certainly, the city has been subjected to various natural hazards (seismic events, but also tsunamis, landslides, etc.) and anthropic calamities (mainly wild and human-induced fires). These features make Valparaíso a paradigmatic study case about hazard mitigation, and risk factors must be very well evaluated during the restoration phases to be planned in the future. Seismic Hazrad. The major goal is to provide a dataset of synthetic time series representative of the potential ground motion at the bedrock of Valparaiso, especially at selected sites (e.g. the three important churches located in the Valparaiso urban area: La Matriz, San Francisco, Las Hermanitas de la Providencia), for different scenarios; the characteristics of the calculated signals (e.g. amplitude, frequency content and duration of shaking) are determined by the earthquake source process and the wave propagation effects of the path between the source and the site. The synthetic signals, to be used as seismic input in a subsequent engineering analysis, have been produced at a very low cost/benefit ratio taking into account a broad range of source characteristics, path and local (geological and geotechnical) conditions. The realistic modeling of ground motion requires the simultaneous knowledge of the geotechnical, lithological, geophysical parameters and topography of the medium, on one side, and tectonic, historical, paleoseismological, seismotectonic models, on the other, for the best possible definition of the probable seismic source. Many parametric studies of the ground motion have been performed, taking into account the variations due to the choice of the focal mechanism parameters, the geometry of the seismic source and the rupture process. Tsunami Hazard. The Chilean coast is currently exposed to the effects of near and far field tsunamis generated in the Pacific Ocean. For instance, the catastrophic events of the last century, 1868 and 1877, overwhelmed the coast of the northern region of the country. This historic situation has contributed to an awareness of the risk involved and therefore to the development of research on the subject in Chile. The organisation in charge of detecting and issuing the warning is the Hydrographic and Oceanographic Service of the Chilean Navy (SHOA). The SHOA report has been used as the reference document for the tsunami hazard assessement for the Valparaiso site and it has been complemented with a) set of parametric studies about the tsunamigenic potential of the 1985 and 1906 scenario earthquakes; b) analytical modelling of tsunami waveforms for different scenarios, in order to provide a complementary dataset to be used for the tsunami hazard assessment at Valparaiso. Using as a base of knowledge the inundation map provided by SHOA associated to the 1906 event, an upper bound of the multiplication factor for the tsunami hazard associated to be used for the different scenarios has been obtained.

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.

Tsunami Hazard in La Réunion Island (SW Indian Ocean): Scenario-Based Numerical Modelling on Vulnerable Coastal Sites

NASA Astrophysics Data System (ADS)

Allgeyer, S.; Quentel, É.; Hébert, H.; Gailler, A.; Loevenbruck, A.

2017-08-01

Several major tsunamis have affected the southwest Indian Ocean area since the 2004 Sumatra event, and some of them (2005, 2006, 2007 and 2010) have hit La Réunion Island in the southwest Indian Ocean. However, tsunami hazard is not well defined for La Réunion Island where vulnerable coastlines can be exposed. This study offers a first tsunami hazard assesment for La Réunion Island. We first review the historical tsunami observations made on the coastlines, where high tsunami waves (2-3 m) have been reported on the western coast, especially during the 2004 Indian Ocean tsunami. Numerical models of historical scenarios yield results consistent with available observations on the coastal sites (the harbours of La Pointe des Galets and Saint-Paul). The 1833 Pagai earthquake and tsunami can be considered as the worst-case historical scenario for this area. In a second step, we assess the tsunami exposure by covering the major subduction zones with syntethic events of constant magnitude (8.7, 9.0 and 9.3). The aggregation of magnitude 8.7 scenarios all generate strong currents in the harbours (3-7 m s^{-1}) and about 2 m of tsunami maximum height without significant inundation. The analysis of the magnitude 9.0 events confirms that the main commercial harbour (Port Est) is more vulnerable than Port Ouest and that flooding in Saint-Paul is limited to the beach area and the river mouth. Finally, the magnitude 9.3 scenarios show limited inundations close to the beach and in the riverbed in Saint-Paul. More generally, the results confirm that for La Runion, the Sumatra subduction zone is the most threatening non-local source area for tsunami generation. This study also shows that far-field coastal sites should be prepared for tsunami hazard and that further work is needed to improve operational warning procedures. Forecast methods should be developed to provide tools to enable the authorities to anticipate the local effects of tsunamis and to evacuate the harbours in sufficient time when such an earthquake occurs.

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.

Summary of Paleotsunami Investigations in Aliomanu, Anahola, Kauai

NASA Astrophysics Data System (ADS)

Griswold, F. R.; La Selle, S.; Richmond, B. M.; Jaffe, B. E.; Gelfenbaum, G. R.; Chague-Goff, C.; LeVeque, R. J.; Bellanova, P.; Sugawara, D.; Nelson, A. R.

2016-12-01

The Hawaiian Islands are susceptible to tsunami hazards from both local and distant sources. Damaging historical tsunamis, such as the 1946 and 1957 Aleutian, and 1960 Chile tsunamis, have been observed in the Hawaiian Islands, but little is known about prehistoric tsunami events. We conducted a field survey in a freshwater marsh in Anahola Valley, on the northeast shore of Kauai, looking for prehistoric tsunami deposits. Cores were collected at 142 sites, spanning to 700 meters inland, using a vibracore, gouge augers, and Russian D-corer. The coring reveals the presence of at least three marine sand layers, which all exhibit a sharp basal contact with underlying marsh peats and muds. The two uppermost sand layers were dated by measuring 137Cs activity in the upper 50 cm of several cores. These sands were likely deposited by the 1946 and 1957 Aleutian tsunamis, both of which were observed by residents in Anahola Valley, with recorded run-ups of 5.2 m and 4.9 m, respectively. The deepest sand layer was deposited approximately 700 cal yr B.P. and may correspond to recently discovered tsunami deposits on Sedanka Island in the Aleutian Islands. In order to characterize the structure and composition of the deeper sand unit, as well as its possible origin, grain size, CT scan, and X-Ray fluorescence data were collected from the cores. We are modeling tsunami propagation and inundation in Anahola Valley to test whether the observed deposits are consistent with an Aleutian subduction zone earthquake source. Additional field investigations and analyses of candidate tsunami deposits are required in order to map the extent of this deposit throughout the Hawaiian Islands and to determine a probable source of this event.

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.

Tsunami exposure estimation with land-cover data: Oregon and the Cascadia subduction zone

USGS Publications Warehouse

Wood, N.

2009-01-01

A Cascadia subduction-zone earthquake has the potential to generate tsunami waves which would impact more than 1000 km of coastline on the west coast of the United States and Canada. Although the predictable extent of tsunami inundation is similar for low-lying land throughout the region, human use of tsunami-prone land varies, creating variations in community exposure and potential impacts. To better understand such variations, land-cover information derived from midresolution remotely-sensed imagery (e.g., 30-m-resolution Landsat Thematic Mapper imagery) was coupled with tsunami-hazard information to describe tsunami-prone land along the Oregon coast. Land-cover data suggest that 95% of the tsunami-prone land in Oregon is undeveloped and is primarily wetlands and unconsolidated shores. Based on Spearman rank correlation coefficients (rs), correlative relationships are strong and statistically significant (p < 0.05) between city-level estimates of the amount of land-cover pixels classified as developed (impervious cover greater than 20%) and the amount of various societal assets, including residential and employee populations, homes, businesses, and tax-parcel values. Community exposure to tsunami hazards, described here by the amount and relative percentage of developed land in tsunami-prone areas, varies considerably among the 26 communities of the study area, and these variations relate to city size. Correlative relationships are strong and significant (p < 0.05) for community exposure rankings based on land-cover data and those based on aggregated socioeconomic data. In the absence of socioeconomic data or community-based knowledge, the integration of hazards information and land-cover information derived from midresolution remotely-sensed imagery to estimate community exposure may be a useful first step in understanding variations in community vulnerability to regional hazards.

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.

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.

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.

Probabilistic assessment of landslide tsunami hazard for the northern Gulf of Mexico

NASA Astrophysics Data System (ADS)

Pampell-Manis, A.; Horrillo, J.; Shigihara, Y.; Parambath, L.

2016-01-01

The devastating consequences of recent tsunamis affecting Indonesia and Japan have prompted a scientific response to better assess unexpected tsunami hazards. Although much uncertainty exists regarding the recurrence of large-scale tsunami events in the Gulf of Mexico (GoM), geological evidence indicates that a tsunami is possible and would most likely come from a submarine landslide triggered by an earthquake. This study customizes for the GoM a first-order probabilistic landslide tsunami hazard assessment. Monte Carlo Simulation (MCS) is employed to determine landslide configurations based on distributions obtained from observational submarine mass failure (SMF) data. Our MCS approach incorporates a Cholesky decomposition method for correlated landslide size parameters to capture correlations seen in the data as well as uncertainty inherent in these events. Slope stability analyses are performed using landslide and sediment properties and regional seismic loading to determine landslide configurations which fail and produce a tsunami. The probability of each tsunamigenic failure is calculated based on the joint probability of slope failure and probability of the triggering earthquake. We are thus able to estimate sizes and return periods for probabilistic maximum credible landslide scenarios. We find that the Cholesky decomposition approach generates landslide parameter distributions that retain the trends seen in observational data, improving the statistical validity and relevancy of the MCS technique in the context of landslide tsunami hazard assessment. Estimated return periods suggest that probabilistic maximum credible SMF events in the north and northwest GoM have a recurrence of 5000-8000 years, in agreement with age dates of observed deposits.

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.

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.

New Seafloor Map of the Puerto Rico Trench Helps Assess Earthquake and Tsunami Hazards

NASA Astrophysics Data System (ADS)

ten Brink, Uri; Danforth, William; Polloni, Christopher; Andrews, Brian; Llanes, Pilar; Smith, Shepard; Parker, Eugene; Uozumi, Toshihiko

2004-09-01

The Puerto Rico Trench, the deepest part of the Atlantic Ocean, is located where the North American (NOAM) plate is subducting under the Caribbean plate (Figure 1). The trench region may pose significant seismic and tsunami hazards to Puerto Rico and the U.S. Virgin Islands, where 4 million U.S. citizens reside. Widespread damage in Puerto Rico and Hispaniola from an earthquake in 1787 was estimated to be the result of a magnitude 8 earthquake north of the islands. A tsunami killed 40 people in NW Puerto Rico following a magnitude 7.3 earthquake in 1918. Large landslide escarpments have been mapped on the seafloor north of Puerto Rico, although their ages are unknown. The Puerto Rico Trench is atypical of oceanic trenches. Subduction is highly oblique (10°-20°) to the trench axis with a large component of left-lateral strike-slip motion. Similar convergence geometry is observed at the Challenger Deep in the Mariana Trench, the deepest point on Earth. In addition to its extremely deep seafloor, the Puerto Rico Trench is also characterized by the most negative free-air gravity anomaly on Earth, -380 mGal, located 50 km south of the trench, where water depth is 7950 m (Figure 2). A tilted carbonate platform provides evidence for extreme vertical tectonism in the region. This platform was horizontally deposited over Cretaceous to Paleocene arc rocks starting in the Late Oligocene. Then, at 3.5 Ma, the carbonate platform was tilted by 4° toward the trench over a time period of less than 40 kyr, such that its northern edge is at a depth of 4000 m and its reconstructed elevation on land in Puerto Rico is at +1300 m (Figures 1 and 2).

Tsunami evacuation analysis, modelling and planning: application to the coastal area of El Salvador

NASA Astrophysics Data System (ADS)

Gonzalez-Riancho, Pino; Aguirre-Ayerbe, Ignacio; Aniel-Quiroga, Iñigo; Abad Herrero, Sheila; González Rodriguez, Mauricio; Larreynaga, Jeniffer; Gavidia, Francisco; Quetzalcoalt Gutiérrez, Omar; Álvarez-Gómez, Jose Antonio; Medina Santamaría, Raúl

2014-05-01

Advances in the understanding and prediction of tsunami impacts allow the development of risk reduction strategies for tsunami-prone areas. Conducting adequate tsunami risk assessments is essential, as the hazard, vulnerability and risk assessment results allow the identification of adequate, site-specific and vulnerability-oriented risk management options, with the formulation of a tsunami evacuation plan being one of the main expected results. An evacuation plan requires the analysis of the territory and an evaluation of the relevant elements (hazard, population, evacuation routes, and shelters), the modelling of the evacuation, and the proposal of alternatives for those communities located in areas with limited opportunities for evacuation. Evacuation plans, which are developed by the responsible authorities and decision makers, would benefit from a clear and straightforward connection between the scientific and technical information from tsunami risk assessments and the subsequent risk reduction options. Scientifically-based evacuation plans would translate into benefits for the society in terms of mortality reduction. This work presents a comprehensive framework for the formulation of tsunami evacuation plans based on tsunami vulnerability assessment and evacuation modelling. This framework considers (i) the hazard aspects (tsunami flooding characteristics and arrival time), (ii) the characteristics of the exposed area (people, shelters and road network), (iii) the current tsunami warning procedures and timing, (iv) the time needed to evacuate the population, and (v) the identification of measures to improve the evacuation process, such as the potential location for vertical evacuation shelters and alternative routes. The proposed methodological framework aims to bridge the gap between risk assessment and risk management in terms of tsunami evacuation, as it allows for an estimation of the degree of evacuation success of specific management options, as well as for the classification and prioritization of the gathered information, in order to formulate an optimal evacuation plan. The framework has been applied to the El Salvador case study through the project "Tsunami Hazard and Risk Assessment in El Salvador", funded by AECID during the period 2009-12, demonstrating its applicability to site-specific response times and population characteristics.

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.

Community exposure to tsunami hazards in Hawai‘i

USGS Publications Warehouse

Jones, Jamie L.; Jamieson, Matthew R.; Wood, Nathan J.

2016-06-17

Community exposure to tsunamis in Hawai‘i varies considerably—some communities may experience great losses that reflect only a small part of their community and others may experience relatively small losses that devastate them. Among the 91 communities and 4 counties, Urban Honolulu has the highest number of people and businesses in the extreme tsunami-inundation zone, and Hanalei has the highest percentages of its people and businesses in this zone. Urban Honolulu has the highest combination of the number and percentage of people, businesses, and facilities in the hazard zone. This report will further the dialogue on societal risk to tsunami hazards in Hawai‘i and help identify future preparedness, mitigation, response, and recovery planning needs within coastal communities and economic sectors of the State of Hawaii. 

The ASTARTE Paleotsunami and Mass Transport Deposits data bases - web-based references for tsunami and submarine landslide research around Europe

NASA Astrophysics Data System (ADS)

De Martini, Paolo Marco; Patera, Antonio; Orefice, Simone; Paris, Raphael; Völker, David; Lastras, Galderic; Terrinha, Pedro; Noiva, João; Smedile, Alessandra; Pantosti, Daniela; Hunt, James; Gutscher, Marc-Andre; Migeon, Sébastien; Papadopoulos, Gerassimos; Triantafyllou, Ioanna; Yalciner, Ahmet C.

2017-04-01

EU project ASTARTE aims at developing a higher level of tsunami hazard assessment in the North East Atlantic, Mediterranean and Connected seas (NEAM) region by a combination of field work, experimental work, numerical modeling and technical development. The project is a cooperative work of 26 institutes from 16 countries and links together the description of past tsunamigenic events, the identification and characterization of tsunami sources, the calculation of the impact of such events, and the development of adequate resilience and risks mitigation strategies (www.astarte.eu). Within ASTARTE two web-based data bases on Paleotsunami and Mass Transport Deposits in the NEAM areas were created with the purpose to be the future information repositories for tsunami research in Europe.The aim is to integrate every existing official scientific reports and peer reviewed papers on these topics and update on new entries every 6-12 months, hosting information and detailed data, that are crucial e.g for tsunami modeling. A relational database managed by ArcGIS for Desktop 10.x software has been implemented. One of the final goals of the project is the public sharing of the archived datasets through a web-based map service that will allow visualizing, querying, analyzing, and interpreting all datasets. The interactive map service will be hosted by ArcGIS Online and will deploy the cloud capabilities of the portal. Any interested users will be able to access the online GIS resources through any Internet browser or specific apps that run on desktop machines, smartphones, or tablets and will be able to use the analytical tools, key tasks, and workflows of the service.We will present the data bases structure and topics as well as their ArcGIS Online version. The research leading to these results has received funding from the European Union's Seventh Framework Programme (FP7/2007-2013) under grant agreement n° 603839 (Project ASTARTE - Assessment, Strategy and Risk Reduction for Tsunamis in Europe).

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 AD 365 earthquake: high resolution tsunami inundation for Crete and full scale simulation exercise

NASA Astrophysics Data System (ADS)

Kalligeris, N.; Flouri, E.; Okal, E.; Synolakis, C.

2012-04-01

In the eastern Mediterranean, historical and archaeological records document major earthquake and tsunami events in the past 2000 year (Ambraseys and Synolakis, 2010). The 1200km long Hellenic Arc has allegedly caused the strongest reported earthquakes and tsunamis in the region. Among them, the AD 365 and AD 1303 tsunamis have been extensively documented. They are likely due to ruptures of the Central and Eastern segments of the Hellenic Arc, respectively. Both events had widespread impact due to ground shaking, and e triggered tsunami waves that reportedly affected the entire eastern Mediterranean. The seismic mechanism of the AD 365 earthquake, located in western Crete, has been recently assigned a magnitude ranging from 8.3 to 8.5 by Shaw et al., (2008), using historical, sedimentological, geomorphic and archaeological evidence. Shaw et al (2008) have inferred that such large earthquakes occur in the Arc every 600 to 800 years, with the last known the AD 1303 event. We report on a full-scale simulation exercise that took place in Crete on 24-25 October 2011, based on a scenario sufficiently large to overwhelm the emergency response capability of Greece and necessitating the invocation of the Monitoring and Information Centre (MIC) of the EU and triggering help from other nations . A repeat of the 365 A.D. earthquake would likely overwhelm the civil defense capacities of Greece. Immediately following the rupture initiation it will cause substantial damage even to well-designed reinforced concrete structures in Crete. Minutes after initiation, the tsunami generated by the rapid displacement of the ocean floor would strike nearby coastal areas, inundating great distances in areas of low topography. The objective of the exercise was to help managers plan search and rescue operations, identify measures useful for inclusion in the coastal resiliency index of Ewing and Synolakis (2011). For the scenario design, the tsunami hazard for the AD 365 event was assessed for the biggest island lying in proximity of the Hellenic Arc, namely Crete. High resolution tsunami inundation modelling was performed for Heraklion and Chania. We use MOST, a non-linear finite difference hydrodynamic model thoroughly benchmarked, coupled with accurate bathymetry and topography data. Also, we used empirical attenuation relationships to estimate the effects of ground shaking on infrastructure complementing the scenario design. Tsunami inundation and ground acceleration maps are presented for the study areas, providing valuable information for earthquake and tsunami hazard.

The California Seafloor and Coastal Mapping Program – Providing science and geospatial data for California's State Waters

USGS Publications Warehouse

Johnson, Samuel Y.; Cochrane, Guy R.; Golden, Nadine; Dartnell, Peter; Hartwell, Stephen; Cochran, Susan; Watt, Janet

2017-01-01

The California Seafloor and Coastal Mapping Program (CSCMP) is a collaborative effort to develop comprehensive bathymetric, geologic, and habitat maps and data for California's State Waters. CSCMP began in 2007 when the California Ocean Protection Council (OPC) and the National Oceanic and Atmospheric Administration (NOAA) allocated funding for high-resolution bathymetric mapping, largely to support the California Marine Life Protection Act and to update nautical charts. Collaboration and support from the U.S. Geological Survey and other partners has led to development and dissemination of one of the world's largest seafloor-mapping datasets. CSCMP provides essential science and data for ocean and coastal management, stimulates and enables research, and raises public education and awareness of coastal and ocean issues. Specific applications include:•Delineation and designation of marine protected areas•Characterization and modeling of benthic habitats and ecosystems•Updating nautical charts•Earthquake hazard assessments•Tsunami hazard assessments•Planning offshore infrastructure•Providing baselines for monitoring change•Input to models of sediment transport, coastal erosion, and coastal flooding•Regional sediment management•Understanding coastal aquifers•Providing geospatial data for emergency response

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).

NOAA's Integrated Tsunami Database: Data for improved forecasts, warnings, research, and risk assessments

NASA Astrophysics Data System (ADS)

Stroker, Kelly; Dunbar, Paula; Mungov, George; Sweeney, Aaron; McCullough, Heather; Carignan, Kelly

2015-04-01

The National Oceanic and Atmospheric Administration (NOAA) has primary responsibility in the United States for tsunami forecast, warning, research, and supports community resiliency. NOAA's National Geophysical Data Center (NGDC) and co-located World Data Service for Geophysics provide a unique collection of data enabling communities to ensure preparedness and resilience to tsunami hazards. Immediately following a damaging or fatal tsunami event there is a need for authoritative data and information. The NGDC Global Historical Tsunami Database (http://www.ngdc.noaa.gov/hazard/) includes all tsunami events, regardless of intensity, as well as earthquakes and volcanic eruptions that caused fatalities, moderate damage, or generated a tsunami. The long-term data from these events, including photographs of damage, provide clues to what might happen in the future. NGDC catalogs the information on global historical tsunamis and uses these data to produce qualitative tsunami hazard assessments at regional levels. In addition to the socioeconomic effects of a tsunami, NGDC also obtains water level data from the coasts and the deep-ocean at stations operated by the NOAA/NOS Center for Operational Oceanographic Products and Services, the NOAA Tsunami Warning Centers, and the National Data Buoy Center (NDBC) and produces research-quality data to isolate seismic waves (in the case of the deep-ocean sites) and the tsunami signal. These water-level data provide evidence of sea-level fluctuation and possible inundation events. NGDC is also building high-resolution digital elevation models (DEMs) to support real-time forecasts, implemented at 75 US coastal communities. After a damaging or fatal event NGDC begins to collect and integrate data and information from many organizations into the hazards databases. Sources of data include our NOAA partners, the U.S. Geological Survey, the UNESCO Intergovernmental Oceanographic Commission (IOC) and International Tsunami Information Center, Smithsonian Institution's Global Volcanism Program, news organizations, etc. NGDC assesses the data and then works to promptly distribute the data and information. For example, when a major tsunami occurs, all of the related tsunami data are combined into one timely resource, posted in an online report, which includes: 1) event summary; 2) eyewitness and instrumental recordings from preliminary field surveys; 3) regional historical observations including similar past events and effects; 4) observed water heights and calculated tsunami travel times; and 5) near-field effects. This report is regularly updated to incorporate the most recent data and observations. Providing timely access to authoritative data and information ultimately benefits researchers, state officials, the media and the public. This paper will demonstrate the extensive collection of data and how it is used.

Tsunamis: Global Exposure and Local Risk Analysis

NASA Astrophysics Data System (ADS)

Harbitz, C. B.; Løvholt, F.; Glimsdal, S.; Horspool, N.; Griffin, J.; Davies, G.; Frauenfelder, R.

2014-12-01

The 2004 Indian Ocean tsunami led to a better understanding of the likelihood of tsunami occurrence and potential tsunami inundation, and the Hyogo Framework for Action (HFA) was one direct result of this event. The United Nations International Strategy for Disaster Risk Reduction (UN-ISDR) adopted HFA in January 2005 in order to reduce disaster risk. As an instrument to compare the risk due to different natural hazards, an integrated worldwide study was implemented and published in several Global Assessment Reports (GAR) by UN-ISDR. The results of the global earthquake induced tsunami hazard and exposure analysis for a return period of 500 years are presented. Both deterministic and probabilistic methods (PTHA) are used. The resulting hazard levels for both methods are compared quantitatively for selected areas. The comparison demonstrates that the analysis is rather rough, which is expected for a study aiming at average trends on a country level across the globe. It is shown that populous Asian countries account for the largest absolute number of people living in tsunami prone areas, more than 50% of the total exposed people live in Japan. Smaller nations like Macao and the Maldives are among the most exposed by population count. Exposed nuclear power plants are limited to Japan, China, India, Taiwan, and USA. On the contrary, a local tsunami vulnerability and risk analysis applies information on population, building types, infrastructure, inundation, flow depth for a certain tsunami scenario with a corresponding return period combined with empirical data on tsunami damages and mortality. Results and validation of a GIS tsunami vulnerability and risk assessment model are presented. The GIS model is adapted for optimal use of data available for each study. Finally, the importance of including landslide sources in the tsunami analysis is also discussed.

Recent Findings on Tsunami Hazards in the Makran Subduction Zone, NW Indian Ocean

NASA Astrophysics Data System (ADS)

Heidarzadeh, M.; Satake, K.

2014-12-01

We present recent findings on tsunami hazards in the Makran subduction zone (MSZ), NW Indian Ocean, based on the results of tsunami source analyses for two Makran tsunamis of 1945 and 2013. A re-analysis of the source of the 27 November 1945 tsunami in the MSZ showed that the slip needs to be extended to deep waters around the depth contour of 3000 m in order to reproduce the observed tide gauge waveforms at Karachi and Mumbai. On the other hand, coastal uplift report at Ormara (Pakistan) implies that the source fault needs to be extended inland. In comparison to other existing fault models, our fault model is longer and includes a heterogeneous slip with larger maximum slip. The recent tsunami on 24 September 2013 in the Makran region was triggered by an inland Mw 7.7 earthquake. While the main shock and all aftershocks were located inland, a tsunami with a dominant period of around 12 min was recorded on tide gauges and a DART station. We examined different possible sources for this tsunami including a mud volcano, a mud/shale diapir, and a landslide/slump through numerical modeling. Only a submarine slump with a source dimension of 10-15 km and a thickness of around 100 m, located 60-70 km offshore Jiwani (Pakistan) at the water depth of around 2000m, was able to reasonably reproduce the observed tsunami waveforms. In terms of tsunami hazards, analyses of the two tsunamis provide new insights: 1) large runup heights can be generated in the coastal areas due to slip in deep waters, and 2) even an inland earthquake may generate tsunamigenic submarine landslides.

Introducing ShakeMap to potential users in Puerto Rico using scenarios of damaging historical and probable earthquakes

NASA Astrophysics Data System (ADS)

Huerfano, V. A.; Cua, G.; von Hillebrandt, C.; Saffar, A.

2007-12-01

The island of Puerto Rico has a long history of damaging earthquakes. Major earthquakes from off-shore sources have affected Puerto Rico in 1520, 1615, 1670, 1751, 1787, 1867, and 1918 (Mueller et al, 2003; PRSN Catalogue). Recent trenching has also yielded evidence of possible M7.0 events inland (Prentice, 2000). The high seismic hazard, large population, high tsunami potential and relatively poor construction practice can result in a potentially devastating combination. Efficient emergency response in event of a large earthquake will be crucial to minimizing the loss of life and disruption of lifeline systems in Puerto Rico. The ShakeMap system (Wald et al, 2004) developed by the USGS to rapidly display and disseminate information about the geographical distribution of ground shaking (and hence potential damage) following a large earthquake has proven to be a vital tool for post earthquake emergency response efforts, and is being adopted/emulated in various seismically active regions worldwide. Implementing a robust ShakeMap system is among the top priorities of the Puerto Rico Seismic Network. However, the ultimate effectiveness of ShakeMap in post- earthquake response depends not only on its rapid availability, but also on the effective use of the information it provides. We developed ShakeMap scenarios of a suite of damaging historical and probable earthquakes that severely impact San Juan, Ponce, and Mayagüez, the 3 largest cities in Puerto Rico. Earthquake source parameters were obtained from McCann and Mercado (1998); and Huérfano (2004). For historical earthquakes that generated tsunamis, tsunami inundation maps were generated using the TIME method (Shuto, 1991). The ShakeMap ground shaking maps were presented to local and regional governmental and emergency response agencies at the 2007 Annual conference of the Puerto Rico Emergency Management and Disaster Administration in San Juan, PR, and at numerous other emergency management talks and training sessions. Economic losses are estimated using the ShakeMap scenario ground motions (Saffar, 2007). The calibration tasks necessary in generating these scenarios (developing Vs30 maps, attenuation relationships) complement the on-going efforts of the Puerto Rico Seismic Network to generate ShakeMaps in real-time.

Communicating Tsunami Preparedness Through the Lessons Learned by Survivors

NASA Astrophysics Data System (ADS)

Kerlow, I.

2015-12-01

Often times science communication is reactive and it minimizes the perceptions of the general public. The Tsunami of New Dreams is a film with the testimonies of survivors of the 2004 Indian Ocean tsunami in Banda Aceh and Aceh Besar in West Sumatra, Indonesia. Production of the film spanned over five years and dozens of interviews, and is based on a unique geographic, demographic and experiential sampling of the local population. This documentary feature film underscores the importance of Earth science and science communication in building sustainable communities. The film is a lesson in survival and sustainability, and it provides a simple but powerful testimony of what to do and what not to do before and during a tsunami. The film also highlights the direct relationship that exists between disaster survival rates and the knowledge of basic Earth science and preparedness facts. We hope that the human stories presented in the film will serve as a strong motivator for general audiences to learn about natural hazards, preparedness, and Earth science. These engaging narratives can touch the minds and hearts of general audiences much faster than technical lectures in a classroom. Some of the testimonies are happy and others are sad, but they all present the wide range of beliefs that influenced the outcomes of the natural disaster. The interviews with survivors are complemented with unique archival footage of the tsunami and unique footage of daily life in Aceh. Hand-drawn illustrations are used to recreate what survivors did immediately after the earthquake, and during the extreme moments when they faced the tsunami waves. Animated visuals, maps and diagrams enhance the understanding of earthquake and tsunami dynamics. The film is a production of the Earth Observatory of Singapore (EOS) in collaboration with the International Center for Aceh and Indian Ocean Studies (ICAIOS) in Banda Aceh, Indonesia. The film is scheduled for release in late 2015. This is a unique work about what we can do to minimize casualties with simple strategies and tactics grounded on Earth science. It is also a case study about the devastating impact of natural hazards in communities with limited awareness of Earth science and the ingenuity and courage necessary to recover from them. http://art-science-media.com/tsunami-of-new-dreams/

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.

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.

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.

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.

A method to estimate expected fatalities and economic loss of buildings in an urban environment as a step toward tsunami risk assessment: an application to the city of Siracusa, Italy.

NASA Astrophysics Data System (ADS)

Pagnoni, Gianluca; Accorsi, Eleonora; Tinti, Stefano

2016-04-01

Siracusa, an important city of the south-east Sicily, is located in an area highly exposed to the danger of tsunami, local and remote. Among the many events that affected this area those with a major effect are the AD 365 tsunami generated by an earthquake in the Western Hellenic Arc, the event of 11 January 1693, following an earthquake in the area of Augusta, and the tsunami of 28 December 1908 generated in the Messina strait. The aim of this study is to evaluate the number of exposed people and of fatalities as well as the type of damage to constructions and the associated loss of economic value in case of a tsunami, based on a simple tsunami scenario, i.e. on assuming a uniform inundation level of 5 m. This figure is considered appropriate for this preliminary tsunami loss analysis since it is compatible with historical tsunami observations and is also supported by recent tsunami hazard studies carried out for this area (Armigliato et al., 2015). The main physical tsunami parameter used in computations is the water column, which is merely the difference between the assumed inundation level and the topographic altitude. We use numerical geo-referenced 1:2000 maps providing a database of constructions in the area of Siracusa together with data from national and local statistical institutions to make estimates on the number and type of buildings and on the number of people that may be found in the inundation area in different periods of the year, discriminating between residents and tourists. Using a variant of the Terrier et al. (2012) table and tsunami mortality curves proposed by Koshimura et al. (2009) we are able to estimate expected fatalities with tsunami inundation reaching at most the first floor of buildings. We calculate economic loss by taking into account both residential buildings and commercial-industrial structures and data from the real estate market. This study is funded by the EU Project ASTARTE - "Assessment, STrategy And Risk Reduction for Tsunamis in Europe", Grant 603839, 7th FP (ENV.2013.6.4-3)

Tsunami Modeling of Hikurangi Trench M9 Events: Case Study for Napier, New Zealand

NASA Astrophysics Data System (ADS)

Williams, C. R.; Nyst, M.; Farahani, R.; Bryngelson, J.; Lee, R.; Molas, G.

2015-12-01

RMS has developed a tsunami model for New Zealand for the insurance industry to price and to manage their tsunami risks. A key tsunamigenic source for New Zealand is the Hikurangi Trench that lies offshore on the eastside of the North Island. The trench is the result of the subduction of the Pacific Plate beneath the North Island at a rate of 40-45 mm/yr. Though there have been no M9 historical events on the Hikurangi Trench, events in this magnitude range are considered in the latest version of the National Seismic Hazard Maps for New Zealand (Stirling et al., 2012). The RMS modeling approaches the tsunami lifecycle in three stages: event generation, ocean wave propagation, and coastal inundation. The tsunami event generation is modeled based on seafloor deformation resulting from an event rupture model. The ocean wave propagation and coastal inundation are modeled using a RMS-developed numerical solver, implemented on graphic processing units using a finite-volume approach to approximate two-dimensional, shallow-water wave equations over the ocean and complex topography. As the tsunami waves enter shallow water and approach the coast, the RMS model calculates the propagation of the waves along the wet-dry interface considering variable land friction. The initiation and characteristics of the tsunami are based on the event rupture model. As there have been no historical M9 events on the Hikurangi Trench, this rupture characterization posed unique challenges. This study examined the impacts of a suite of event rupture models to understand the key drivers in the variations in the tsunami inundation footprints. The goal was to develop a suite of tsunamigenic event characterizations that represent a range of potential tsunami outcomes for M9 events on the Hikurangi Trench. The focus of this case study is the Napier region as it represents an important exposure concentration in the region and has experience tsunami inundations in the past including during the 1931 Ms7.8 Hawkes Bay Earthquake.

Role of Compressibility on Tsunami Propagation

NASA Astrophysics Data System (ADS)

Abdolali, Ali; Kirby, James T.

2017-12-01

In the present paper, we aim to reduce the discrepancies between tsunami arrival times evaluated from tsunami models and real measurements considering the role of ocean compressibility. We perform qualitative studies to reveal the phase speed reduction rate via a modified version of the Mild Slope Equation for Weakly Compressible fluid (MSEWC) proposed by Sammarco et al. (2013). The model is validated against a 3-D computational model. Physical properties of surface gravity waves are studied and compared with those for waves evaluated from an incompressible flow solver over realistic geometry for 2011 Tohoku-oki event, revealing reduction in phase speed.