WorldWideScience
 
 
1

Landslide-generated tsunamis in a perialpine lake: Historical events and numerical models  

Science.gov (United States)

Many of the perialpine lakes in Central Europe - the large, glacier-carved basins formed during the Pleistocene glaciations of the Alps - have proven to be environments prone to subaquatic landsliding. Among these, Lake Lucerne (Switzerland) has a particularly well-established record of subaquatic landslides and related tsunamis. Its sedimentary archive documents numerous landslides over the entire Holocene, which have either been triggered by earthquakes, or which occurred apparently spontaneously, possibly due to rapid sediment accumulation on delta slopes. Due to their controlled boundary conditions and the possibility to be investigated on a complete basinal scale, such lacustrine tsunamis may be used as textbook analogons for their marine counterparts. Two events in the 17th century illustrate these processes and their consequences: In AD 1601, an earthquake (Mw ~ 5.9) led to widespread failure of the sediment drape covering the lateral slopes in several basins. The resulting landslides generated tsunami waves that reached a runup of several metres, as reported in historical accounts. The waves caused widespread damage as well as loss of lives in communities along the shores. In AD 1687, the apparently spontaneous collapse of a river delta in the lake led to similar waves that damaged nearby villages. Based on detailed information on topography, bathymetry and the geometry of the landslide deposits, numerical simulations combining two-dimensional, depth-averaged models for landslide propagation, as well as for tsunami generation, propagation and inundation, are able to reproduce most of the reported tsunami effects for these events. Calculated maximum runup of the waves is 6 to >10 m in the directly affected lake basins, but significantly less in neighbouring basins. Flat alluvial plains adjacent to the most heavily affected areas are inundated over distances of several hundred metres. Taken as scenarios for possible future events, these past events suggest that tsunami hazard in these lake should not be neglected, although they are infrequent and the effects are naturally limited to the immediate surroundings of the affected basins. The shores of Lake Lucerne, as well as of many other perialpine lakes, are nowadays densely inhabited and host considerable infrastructure, so that events similar to those reported may have serious consequences. Identification and mapping of possible subaquatic landslide source areas, the inclusion of geotechnical data on potentially mobile sediments, as well as numerical modelling of tsunamis are thus important components of a proper hazard assessment for these lakes.

Hilbe, Michael; Anselmetti, Flavio S.

2014-05-01

2

Tsunami Warning Criteria for Cascadia events based on Tsunami models  

Science.gov (United States)

Initial tsunami warning, advisory, and watch zones for potential Cascadia earthquakes have been revised based on maximum expected threat for tsunamis generated by earthquakes in this region. Presently, alert zones are initially based on travel time for earthquakes greater than magnitude 7.8 with all areas less than three hours away from the source being put into a tsunami warning. The impact of this change is to reduce the length of coastline which is immediately put it into a warning status. Tsunami Warning Centers often delineate initial tsunami alert zones based on pre-set criteria dependent on earthquake magnitude, location, depth, and tsunami travel time. In many cases, this approach can lead to over-warning. Over the last several years, the West Coast/Alaska Tsunami Warning Center (WCATWC) has attempted to refine the amount of coastline immediately placed in a warning status based on maximum expected threat instead of travel time. Tsunami forecast models used to predict impacts during events (for example, Alaska Tsunami Forecast Model (ATFM), Short-term Inundation Forecasting for Tsunamis (SIFT), and Rapid Inundation Forecasting of Tsunamis (RIFT)) can also be used a-priori to delineate zones at-risk for specified source zones. forecast models have proven reasonably accurate during recent events. For the Cascadia Subduction zone, several rupture scenarios ranging from magnitude 7.9 to 9.2, were computed. Forecasted wave heights at various points are then used to set the initial Warning/Watch/Advisory regions. This procedure is more efficient than a blanket warning - or a refined warning based on travel times - as appropriate threat levels are assigned based on expected impact. For example, after a magnitude 8.7 earthquake in the southern Cascadia Subduction zone, southern and most of central California can be left out of the warning zone and placed in an advisory, as none of this region contains expected impacts in the warning threshold (tsunami amplitude over 1m). Under previous criteria, these zones would have been placed in a warning. Several examples are shown which help refine criteria used by the Tsunami Warning Center during hypothetical Cascadia events.

Huang, P. Y.; Nyland, D. L.; Knight, W.; Gately, K.; Hale, D.; Urban, G.; Waddell, J.; Carrick, J.; Popham, C.; Bahng, B.; Kim, Y.; Burgy, M.; Langley, S.; Preller, C. C.; Whitmore, P.

2013-12-01

3

Identifying generation mechanisms in U.S. east coast non-seismic tsunami events  

Science.gov (United States)

On April 11, and June 13, 2013 two long-period water level anomalies were recorded at different locations along the northeastern seaboard of the United States. Wave amplitudes reached almost 10 centimeters in deep water, as recorded at DART buoy 44402 and 20 to 30 centimeters at coastal tide gauges in Rhode Island, Massachusetts, New York and New Jersey. Smaller signatures were seen in tide gauges as far away as Bermuda and Puerto Rico. There seems to be circumstantial evidence indicating a meteorological origin for the June 13 event, however, that explanation is less compelling for the event of April 11. Moreover, travel time contours trace the origin of both perturbations back to an area located in the vicinity of Hudson Canyon. A preliminary bathymetric survey of the walls of the canyon failed to locate any recent landslide evidence, and forward modeling of potential landslides in the canyon indicates that a larger source would have been needed to generate the kind of wavelengths recorded during this event. A model using a source just shoreward of the canyon shows arrival times that agree well with data at both the DART buoy and the tide gauges, but fails to reproduce some large amplitude waves within Delaware Bay that may, indeed, be atmospherically forced. The present study tries to identify possible landslide sources of this non-seismic tsunami, primarily located along the continental break outside of the Hudson Canyon. Failure to identify any such sources will strengthen the hypothesis of a meteotsunami. Positive identification of potential landslide sources may open up additional lines of investigation as to the real source of the event.

Moore, C. W.; Arcas, D.; Kanoglu, U.; Titov, V.; Gonzalez-Vida, J.

2013-12-01

4

The BIG'95 event, Balearic Islands, Western Mediterranean Sea: numerical simulation of the possibly generated tsunami  

Science.gov (United States)

The BIG'95 debris flow that occurred ~11 kyrs BP affected an area of about 2200 km2 of the Ebro margin, in the Western Mediterranean Sea. The debris flow originated at the upper continental slope and involved a sediment volume of ~26 km3. After a total runout of 110 km the distalmost deposits resulting from this mass movement partly filled the upper course of the Valencia Channel at 2000 m depth. Multibeam bathymetry and backscatter maps, deep-towed side scan images, high-resolution seismic reflection profiles, submarine video records, sedimentological and mass physical properties measurement on sediment cores, and in situ geotechnical tests constitute a valuable dataset providing the basis to model the landslide evolution. Different observational elements in this data set jointly with numerical modelling simulations suggest that the downslope mass movement was rather fast (i.e. peak velocities of 50 ms-1 and 20 ms-1 have been reported for the loose sediment fraction and individual blocks, respectively). It was subsequently inferred that the BIG'95 could have generated a tsunami potentially impacting the Balearic and the Spanish coasts. In this work we explore the tsunamigenic potential of the BIG'95 by applying numerical codes that have been developed by the University of Bologna Tsunami Research Team. The code UBO-BLOCK is used for the simulation of the slide motion on a Lagrangian grid moving along with the body: the mass is split into a set of interacting blocks, that conserve the volume but can change their shape. The movement of the mass on the sea bottom generates tsunami impulses that are calculated and interpolated on the static tsunami computational grid by the intermediate code UBO-TSUIMP. The tsunami propagation is computed via the code UBO-TSUFE, solving the Navier-Stokes equations in the shallow water approximation on the computational domain, constituted by triangles whose dimension depends on the local sea depth. This work has been performed in the framework of the EU-funded project TRANSFER, dealing with the study of tsunamis in the Mediterranean Sea, from the possible sources to the assessment of the risk along the coasts.

Tinti, S.; Canals, M.; Pagnoni, G.; Zaniboni, F.; Iglesias, O.; Lastras, G.

2009-04-01

5

Tsunami!  

Science.gov (United States)

A general introduction to tsunamis including information about the mechanisms of tsunami generation and propagation, the impact of tsunamis on humankind, and the Tsunami Warning System. Sections include information on what tsunami means, how earthquakes, landslides, volcanic eruptions and meteorites generate tsunamis, and what happens when a tsunami approaches and encounters land. Also included is information on past and recent tsunami activity, a fact sheet on what to do if threatened by a tsunami, as well as links to the Tsunami Warning System and related sites. Users can also find information on tsunami research centers and projects.

6

Landslide tsunami case studies using a Boussinesq model and a fully nonlinear tsunami generation model  

Directory of Open Access Journals (Sweden)

Full Text Available Case studies of landslide tsunamis require integration of marine geology data and interpretations into numerical simulations of tsunami attack. Many landslide tsunami generation and propagation models have been proposed in recent time, further motivated by the 1998 Papua New Guinea event. However, few of these models have proven capable of integrating the best available marine geology data and interpretations into successful case studies that reproduce all available tsunami observations and records. We show that nonlinear and dispersive tsunami propagation models may be necessary for many landslide tsunami case studies. GEOWAVE is a comprehensive tsunami simulation model formed in part by combining the Tsunami Open and Progressive Initial Conditions System (TOPICS with the fully non-linear Boussinesq water wave model FUNWAVE. TOPICS uses curve fits of numerical results from a fully nonlinear potential flow model to provide approximate landslide tsunami sources for tsunami propagation models, based on marine geology data and interpretations. In this work, we validate GEOWAVE with successful case studies of the 1946 Unimak, Alaska, the 1994 Skagway, Alaska, and the 1998 Papua New Guinea events. GEOWAVE simulates accurate runup and inundation at the same time, with no additional user interference or effort, using a slot technique. Wave breaking, if it occurs during shoaling or runup, is also accounted for with a dissipative breaking model acting on the wave front. The success of our case studies depends on the combination of accurate tsunami sources and an advanced tsunami propagation and inundation model.

P. Watts

2003-01-01

7

Tsunami: ocean dynamo generator.  

Science.gov (United States)

Secondary magnetic fields are induced by the flow of electrically conducting seawater through the Earth's primary magnetic field ('ocean dynamo effect'), and hence it has long been speculated that tsunami flows should produce measurable magnetic field perturbations, although the signal-to-noise ratio would be small because of the influence of the solar magnetic fields. Here, we report on the detection of deep-seafloor electromagnetic perturbations of 10-micron-order induced by a tsunami, which propagated through a seafloor electromagnetometer array network. The observed data extracted tsunami characteristics, including the direction and velocity of propagation as well as sea-level change, first to verify the induction theory. Presently, offshore observation systems for the early forecasting of tsunami are based on the sea-level measurement by seafloor pressure gauges. In terms of tsunami forecasting accuracy, the integration of vectored electromagnetic measurements into existing scalar observation systems would represent a substantial improvement in the performance of tsunami early-warning systems. PMID:24399356

Sugioka, Hiroko; Hamano, Yozo; Baba, Kiyoshi; Kasaya, Takafumi; Tada, Noriko; Suetsugu, Daisuke

2014-01-01

8

Advanced Simulation of Coupled Earthquake and Tsunami Events (ASCETE) - Latest Simulation Techniques for Tsunami Process Studies  

Science.gov (United States)

The ASCETE project develops a simulation framework for coupled physics-based rupture generation with tsunami propagation and inundation. Recently, several new results could be achieved. Adaptive mesh tsunami propagation and inundation by discontinuous Galerkin Runge-Kutta methods allows for accurate and conservative inundation schemes. The adaptive mesh refinement allows for efficiency optimization, since computations are only performed in areas of interest and wave activity. A tree-based refinement strategy is utilized to highly optimize the code for high-performance computing architectures. Rupture simulation is performed by an unstructured tetrahedral discontinuous Galerking ADER discretization, which allows for accurate representation of complex geometries. Advanced meshing methods allow for near-realistic geometrical set-ups. Currently physically consistent state of stress and frictional strength properties inspired from seismo-thermo-mechanical models are implemented, opening the path to cutting edge process studies of earthquakes in megathrust and off-megathrust faulting systems. Code optimizations with automatic code generation tools for vector performance show gains in execution time of a factor of five and more. First results of coupled simulations with complex time-dependent rupture mechanics and correspondingly triggered tsunami events demonstrate the potential for novel process studies and uncertainty assessment of realistic events.

Behrens, Joern; Bader, Michael; Breuer, Alexander N.; Dalguer, Luis A.; Gabriel, Alice-A.; Galvez Barron, Percy E.; Pelties, Christian; Rahnema, Kaveh; Vater, Stefan

2014-05-01

9

An Educational Tool for a New Generation of Tsunami Scientists  

Science.gov (United States)

What emerges from the 2004 Indian Ocean tsunami and society's response is a call for research that will mitigate the effects of the next tsunami on society. The scale of the 2004 tsunami's impact (227,000 deaths, 10B damage), and the world's compassionate response (13.5B), requires that tsunami research focus on applications that benefit society. Tsunami science will be expected to develop standards that ensure mitigation products are based on state-of-the-science. Standards based on scientifically endorsed procedures assure the highest quality application of this science. Community educational activities will be expected to focus on preparing society for the next tsunami. An excellent starting point for the challenges ahead is education, at all levels, including practitioners, the public, and a new generation of tsunami scientists. To educate the new generation of scientists, Volume 15 of The Sea: Tsunamis has been written to capture the technical elements of tsunami state-of-the-science today. The volume includes: the recorded and geologic history of tsunamis and how to assess the probability of the tsunami risk; the generation of tsunamis; the measurement and modeling of tsunami propagation and inundation; the impacts of tsunamis on coastlines; and tsunami forecast and warnings. Together, this volume gives a technical foundation to apply tsunami science to community-based tsunami preparedness. The editors of The Sea: Tsunamis will present an overview of the volume with emphasis on its value to higher education.

Bernard, E. N.; Robinson, A. R.

2008-12-01

10

VOLCANIC TSUNAMI GENERATING SOURCE MECHANISMS IN THE EASTERN CARIBBEAN REGION  

Directory of Open Access Journals (Sweden)

Full Text Available Earthquakes, volcanic eruptions, volcanic island flank failures and underwater slides have generated numerous destructive tsunamis in the Caribbean region. Convergent, compressional and collisional tectonic activity caused primarily from the eastward movement of the Caribbean Plate in relation to the North American, Atlantic and South American Plates, is responsible for zones of subduction in the region, the formation of island arcs and the evolution of particular volcanic centers on the overlying plate. The inter-plate tectonic interaction and deformation along these marginal boundaries result in moderate seismic and volcanic events that can generate tsunamis by a number of different mechanisms. The active geo-dynamic processes have created the Lesser Antilles, an arc of small islands with volcanoes characterized by both effusive and explosive activity. Eruption mechanisms of these Caribbean volcanoes are complex and often anomalous. Collapses of lava domes often precede major eruptions, which may vary in intensity from Strombolian to Plinian. Locally catastrophic, short-period tsunami-like waves can be generated directly by lateral, direct or channelized volcanic blast episodes, or in combination with collateral air pressure perturbations, nuéss ardentes, pyroclastic flows, lahars, or cascading debris avalanches. Submarine volcanic caldera collapses can also generate locally destructive tsunami waves. Volcanoes in the Eastern Caribbean Region have unstable flanks. Destructive local tsunamis may be generated from aerial and submarine volcanic edifice mass edifice flank failures, which may be triggered by volcanic episodes, lava dome collapses, or simply by gravitational instabilities. The present report evaluates volcanic mechanisms, resulting flank failure processes and their potential for tsunami generation. More specifically, the report evaluates recent volcanic eruption mechanisms of the Soufriere Hills volcano on Montserrat, of Mt. Pelée on Martinique, of Soufriere on St. Vincent and of the Kick’em Jenny underwater volcano near Grenada and provides an overall risk assessment of tsunami generation from volcanic sources in the Caribbean region.

George Pararas-Carayannis

2004-01-01

11

Tsunami Impact from a 1755-like event in the Aveiro Region, Portugal  

Science.gov (United States)

In this study, we present 5m-resolution tsunami flooding maps for the Aveiro region, W. Central Portugal. Aveiro is known to have been impacted by the 1st November 1755 earthquake and tsunami. At that time this portion of the coast had almost no constructions nor population but eversince geomorphological changes took place, and there has been a very large population increase living in constructions extremely close to the shore. As such it is important to model and evaluate the potential impact that a similar event to the 1755 earthquake would have in this area at present. Tsunami flooding maps were computed using a digital elevation model produced from the present-day bathymetric and topographic data including bathymetric surveys, LiDAR and photogrammetric data. Tsunami scenarios were generated considering different solutions for the 1755 earthquake seismic source, in faults constrained by multibeam and multichannel seismic data. The modeling of the tsunami propagation was performed with a validated non-linear shallow water model. To compute inundation, we considered four levels of nested grids with resolutions ranging from 320m to 5m. The tsunami-associated flood is discussed in terms of flow depth, run-up height and maximum inundation area. The Ria de Aveiro is characterized by both flattened relief and significant tidal amplitude range, which can contribute to an important variation in flooding due to tsunami-tide interaction. Therefore, the effect of the tide variation on the extent of tsunami inundation is also discussed. Results are compared with the historical descriptions of the consequences in Aveiro. An event similar to the one from 1755 would cause tsunami run-up heights above one meter within the Ria de Aveiro. The Aveiro oceanic coast would also be strongly affected. The results obtained can be used to identify the potential tsunami inundation areas in Aveiro, which is important for the Portuguese tsunami emergency management system. Keywords: Inundation, DEM, Numerical Modeling, Ria de Aveiro, LiDAR

Lemos, Catarina R.; Omira, Rachid; Pinheiro, Luis M.; Baptista, Maria A.; Quaresma, Luis S.; Garrido, Carla

2014-05-01

12

Detailed analysis of tsunami waveforms generated by the 1946 Aleutian tsunami earthquake  

Directory of Open Access Journals (Sweden)

Full Text Available The 1946 Aleutian earthquake was a typical tsunami earthquake which generated abnormally larger tsunami than expected from its seismic waves. Previously, Johnson and Satake (1997 estimated the fault model of this earthquake using the tsunami waveforms observed at tide gauges. However, they did not model the second pulse of the tsunami at Honolulu although that was much larger than the first pulse. In this paper, we numerically computed the tsunami waveforms using the linear Boussinesq equation to determine the fault model which explains the observed tsunami waveforms including the large second pulse observed at Honolulu. The estimated fault width is 40–60 km which is much narrower than the fault widths of the typical great underthrust earthquakes, the 1957 Aleutian and the 1964 Alasuka earthquakes. A previous study of the 1896 Sanriku earthquake, another typical tsunami earthquake, suggested that the additional uplift of the sediments near the Japan Trench had a large effect on the tsunami generation. In this study, we also show that the additional uplift of the sediments near the trench, due to a large coseismic horizon-tal movement of the backstop, had a significant effect on the tsunami generation of the 1946 Aleutian earthquake. The estimated seismic moment of the 1946 Aleutian earthquake is 17–19 × 1020 20 Nm (Mw 8.1.

Y. Tanioka

2001-01-01

13

Numerical modelling of historical landslide-generated tsunamis in the French Lesser Antilles  

Directory of Open Access Journals (Sweden)

Full Text Available Two historical landslide-induced tsunamis that reached the coasts of the French Lesser Antilles are studied. First, the Martinique coast was hit by a tsunami down the western flank of Montagne Pelée at the beginning of the big eruption of May 1902. More recently, the northeastern coast of Guadeloupe was affected by a tsunami that had been generated around Montserrat by pyroclastic flows entering the sea, during the July 2003 eruption of the Soufrière Hills volcano. We use a modified version of the GEOWAVE model to compute numerical simulations of both events. Two source hypotheses are considered for each tsunami. The comparison of the simulation results with reported tsunami height data helps to discriminate between the tested source decriptions. In the Martinique case, we obtain a better fit to data when considering three successive lahars entering the sea, as a simplified single source leads to an overstimation of the tsunami wave heights at the coast. In the Montserrat case, the best model uses a unique source which volume corresponds to published data concerning the peak volume flow. These findings emphasize the importance of an accurate description of the relevant volume as well as the timing sequence of the source event in landslide-generated tsunami modelling. They also show that considering far-field effects in addition to near-field effects may significantly improve tsunami modelling.

B. Poisson

2010-06-01

14

Case study of tsunami generated by sector collapse within bay area  

Science.gov (United States)

Tsunamis generated by sector collapse of volcano are widely noticed as spectacular natural hazard. However, tsunamis generated by collapse within bay area are sparsely focused. We selected the Beppu bay located in Kyushu island northeastern of Japan as an example and did the case study of the tsunami generated by the sector collapse within bay area. In case of large-scale sector collapse on the eastern slope of the Tsurumi-dake volcano, there is a possibility that the tsunami is generated by debris avalanches rush into the Beppu Bay. For this reason, we evaluated the water height of tsunami caused by the sector collapse on Tsurumi-dake using the numerical simulation. We classified volcanic bodies based on aerial-photo interpretation and geological survey, and examined a large-scale sector collapse that was able to generate tsunami.TITAN2D (Patra et al., 2004) was used to set the parameters for the numerical simulation of tsunami generation by the sector collapse. Kinematic Landslide Model (Satake and Kato, 2002) and Two layer model (Imamura et al., 2001), (Maeno and Imamura, 2007) were used for the numerical simulation of the tsunami. As a result of simulation, in the event of large-scale sector collapse occurred on the eastern slope of the Tsurumi-dake volcano, comparatively large-scale tsunami is assumed in the Beppu bay. Moreover, it was shown that the influence outside the Beppu bay was small though the main wave of the tsunami headed in the direction from the Beppu bay to the Honshu island.

Ishikawa, Y.; Nishizaka, N.; Ogiyama, K.; Tsuji, T.; Yamamoto, K.; Tsuchiya, S.; Nagaoka, S.

2011-12-01

15

Tsunami flooding  

Science.gov (United States)

Panel 5 focused on tsunami flooding with an emphasis on Probabilistic Tsunami Hazard Analysis (PTHA) as derived from its counterpart, Probabilistic Seismic Hazard Analysis (PSHA) that determines seismic ground-motion hazards. The Panel reviewed current practices in PTHA and determined the viability of extending the analysis to extreme design probabilities (i.e., 10-4 to 10-6). In addition to earthquake sources for tsunamis, PTHA for extreme events necessitates the inclusion of tsunamis generated by submarine landslides, and treatment of the large attendant uncertainty in source characterization and recurrence rates. Tsunamis can be caused by local and distant earthquakes, landslides, volcanism, and asteroid/meteorite impacts. Coastal flooding caused by storm surges and seiches is covered in Panel 7. Tsunamis directly tied to earthquakes, the similarities with (and path forward offered by) the PSHA approach for PTHA, and especially submarine landslide tsunamis were a particular focus of Panel 5.

Geist, Eric; Jones, Henry; McBride, Mark; Fedors, Randy

2013-01-01

16

The TRIDEC Virtual Tsunami Atlas - customized value-added simulation data products for Tsunami Early Warning generated on compute clusters  

Science.gov (United States)

The development of new Tsunami Early Warning Systems (TEWS) requires the modelling of spatio-temporal spreading of tsunami waves both recorded from past events and hypothetical future cases. The model results are maintained in digital repositories for use in TEWS command and control units for situation assessment once a real tsunami occurs. Thus the simulation results must be absolutely trustworthy, in a sense that the quality of these datasets is assured. This is a prerequisite as solid decision making during a crisis event and the dissemination of dependable warning messages to communities under risk will be based on them. This requires data format validity, but even more the integrity and information value of the content, being a derived value-added product derived from raw tsunami model output. Quality checking of simulation result products can be done in multiple ways, yet the visual verification of both temporal and spatial spreading characteristics for each simulation remains important. The eye of the human observer still remains an unmatched tool for the detection of irregularities. This requires the availability of convenient, human-accessible mappings of each simulation. The improvement of tsunami models necessitates the changes in many variables, including simulation end-parameters. Whenever new improved iterations of the general models or underlying spatial data are evaluated, hundreds to thousands of tsunami model results must be generated for each model iteration, each one having distinct initial parameter settings. The use of a Compute Cluster Environment (CCE) of sufficient size allows the automated generation of all tsunami-results within model iterations in little time. This is a significant improvement to linear processing on dedicated desktop machines or servers. This allows for accelerated/improved visual quality checking iterations, which in turn can provide a positive feedback into the overall model improvement iteratively. An approach to set-up and utilize the CCE has been implemented by the project Collaborative, Complex, and Critical Decision Processes in Evolving Crises (TRIDEC) funded under the European Union's FP7. TRIDEC focuses on real-time intelligent information management in Earth management. The addressed challenges include the design and implementation of a robust and scalable service infrastructure supporting the integration and utilisation of existing resources with accelerated generation of large volumes of data. These include sensor systems, geo-information repositories, simulations and data fusion tools. Additionally, TRIDEC adopts enhancements of Service Oriented Architecture (SOA) principles in terms of Event Driven Architecture (EDA) design. As a next step the implemented CCE's services to generate derived and customized simulation products are foreseen to be provided via an EDA service for on-demand processing for specific threat-parameters and to accommodate for model improvements.

Löwe, P.; Hammitzsch, M.; Babeyko, A.; Wächter, J.

2012-04-01

17

Tsunami Modeling from Submarine Landslides  

Science.gov (United States)

This paper describes a kinematic model that computes tsunamis generated from submarine landslides. The model is based on bathymetric (ocean floor modeling) data and historical tsunami data. The papers' main focus is the application of the model to the 1741 Oshima-Oshima Tsunami in Japan and landslide events around the Hawaiian Islands. This paper was presented at the U.S. National Tsunami Hazard Mitigation Program Review and International Tsunami Symposium in Seattle, Washington on August 10, 2001.

Satake, Kenji; National Oceanic and Atmospheric Administration (NOAA)

18

Tsunamis  

Science.gov (United States)

... of the shoreline. Drowning is the most common cause of death associated with a tsunami. Tsunami waves and the receding water are very ... of any building that has water around it. Tsunami water can cause floors to crack or walls to collapse. Use ...

19

Simulation of the minor tsunami generated by the September 30 2009 earthquake near Padang, Sumatra  

Science.gov (United States)

The magnitude 7.6 earthquake (USGS) on September 30, 2009 at 10:16 UTC close to the city of Padang in West Sumatra generated a minor tsunami. Earthquakes in this region however have the potential to generate destructive waves as it was shown in historical and recent events. Taking into account the large number of casualties due to this earthquake it is important to prepare for possible future events which might be accompanied by a tsunami. Due to the geographical setting of Padang a tsunami might have disastrous impact. An effective early warning system is crucial. The tsunami modeling group of Alfred Wegener Institute is part of the GITEWS project (German Indonesian Tsunami Early Warning System) and is responsible for creating a database of pre-calculated tsunami scenarios of various magnitudes and epicenter locations covering the Sunda Trench. These scenarios are calculated with the newly developed model TsunAWI. It is based on the nonlinear shallow water equations and employs the finite element method in unstructured meshes. In case of a tsunamigenic earthquake, sensor data (comprising seismometers, GPS instruments, tide gauges, buoys and ocean bottom pressure sensors) will be evaluated. The most probable scenario will be selected and used to forecast arrival times and estimated wave height along the coast. The unstructured discretisation employed in TsunAWI allows for a high resolution around the city of Padang. In this presentation we show preliminary examples of the results of the GITEWS simulation system. We evaluate our pre-computed scenarios and analyze their deficiencies. Additional simulations based on diverse source models are performed to analyze the predictability of near-field tsunamis within short time. We compare simulation results to tide gauge data from Padang harbor and find good agreement.

Wekerle, C.; Harig, S.; Pranowo, W.; Behrens, J.; Androsov, A.; Schroeter, J.; Hiller, W.

2009-12-01

20

Nonlinear mechanism of tsunami wave generation by atmospheric disturbances  

Directory of Open Access Journals (Sweden)

Full Text Available The problem of tsunami wave generation by variable meteo-conditions is discussed. The simplified linear and nonlinear shallow water models are derived, and their analytical solutions for a basin of constant depth are discussed. The shallow-water model describes well the properties of the generated tsunami waves for all regimes, except the resonance case. The nonlinear-dispersive model based on the forced Korteweg-de Vries equation is developed to describe the resonant mechanism of the tsunami wave generation by the atmospheric disturbances moving with near-critical speed (long wave speed. Some analytical solutions of the nonlinear dispersive model are obtained. They illustrate the different regimes of soliton generation and the focusing of frequency modulated wave packets.

E. Pelinovsky

2001-01-01

 
 
 
 
21

Tsunami generation, propagation, and run-up with a high-order Boussinesq model  

DEFF Research Database (Denmark)

In this work we extend a high-order Boussinesq-type (finite difference) model, capable of simulating waves out to wavenumber times depth kh <25, to include a moving sea-bed, for the simulation of earthquake- and landslide-induced tsunamis. The extension is straight forward, requiring only an additional term within the kinematic bottom condition. As first test cases we simulate linear and nonlinear surface waves generated from both positive and negative impulsive bottom movements. The computed results compare well against earlier theoretical, numerical, and experimental values. Additionally, we show that the long-time (fully nonlinear) evolution of waves resulting from an upthrusted bottom can eventually result in true solitary waves, consistent with theoretical predictions. It is stressed, however, that the nonlinearity used far exceeds that typical of geophysical tsunamis in the open ocean. The Boussinesq-type model is then used to simulate numerous tsunami-type events generated from submerged landslides, inboth one and two horizontal dimensions. The results again compare well against previous experiments and/or numerical simulations. The new extension compliments recently developed run-up capabilities within this approach, and as demonstrated, the model can therefore treat tsunami events from their initial generation, through their later propagation, and final run-up phases. The developed model is shown to maintain reasonable computational efficiency, and is therefore attractive for the simulation of such events, especially in cases where dispersion is important.

Fuhrman, David R.; Madsen, Per A.

2009-01-01

22

Tsunamis  

Science.gov (United States)

Deanne Erdmann and Nancy Moreno of Baylor College of Medicine contributed to BioEd OnlineâÂÂs âÂÂHot Topics in Biologyâ with this website on tsunamis. This online article provides a brief overview of tsunamis, explaining what exactly a tsunami is and the impact they have had on the world. Another valuable part of this website is the supplemental information, this includes a slideshow available for download, links to recent news stories about tsunamis, and a list of great additional online resources from places such as Discovery, and NASA.

Erdmann, Deanne; Moreno, Nancy

2008-07-09

23

Recent and Historical Tsunami Events and Relevant Data  

Science.gov (United States)

... all U.S. interests in the Pacific outside the West Coast/Alaska Tsunami Warning Center area of responsibility, most countries in the Pacific and around its rim. NOAA Tsunami Warning Centers National Tsunami Warning Center US mainland, Canada, Puerto Rico and the Virgin Islands ( ...

24

Coastal vegetation and its influence on the 2004 tsunami event  

Science.gov (United States)

A tsunami event has several effects once it reaches the shore. Infrastructure damage and casualties are two of its most dire consequences. The intensity of these damages is related to the wave force, which in turn is mostly determined by seaquake intensity and offshore properties. Nevertheless, once on land, the energy of the wave is attenuated by gravity (elevation) and friction (land cover). Despite being promoted as 'bio-shields' against wave impact, tree-belts lack quantitative evidence of their performance in such extreme events, and have been criticized for creating a false sense of security. We have studied some of the land uses in sites affected by the 2004 tsunami event, especially in coastal areas close to the coast of Indonesia, more specifically in the west coast of Aceh, Sumatra. Using transects perpendicular to the coast we analyzed the influence of coastal vegetation, particularly cultivated trees, on the impact of the 2004 tsunami. We developed a spatial statistical model that uses a land cover roughness coefficient to account for the resistance offered by different land uses to the wave advance. The coefficient was built using satellite imagery, land cover maps, land use characteristics such as stem diameter, height, and planting density, as well as a literature review. The spatial generalized linear mixed models used determined that while distance to coast was the dominant determinant of impact (casualties and infrastructure damage), the existing coastal vegetation in front of settlements also significantly reduced casualties by an average of 5%. Despite this positive effect of coastal vegetation in front of a settlement, we also found out that dense vegetation behind villages endangered human lives and increased structural damage. We believe that possibly debris carried by the backwash may have contributed to these dissimilar effects of land cover. The models developed in Indonesia are currently being adapted and tested for the effects that the same tsunami event caused in the Seychelles, where the intensity of the wave was a tenth of that in Aceh. On the Seychelles, our current work suggests that no direct effect of coastal vegetation existed. At the same time, our results indicate that vegetation maintained dunes seemed to offer a decrease of the probability of structural damage. We believe that instead of advocating for or against tree belts, a sustainable and effective coastal risk management should be promoted. This should include smart planning for the location (relative to the sea) of settlements but also consider the possible roles of coastal vegetation, as determined by its spatial arrangement. Overall, for any of these planning measures to be sustainable, coastal vegetation must be regarded as an important livelihood provider rather than just as a bio-shield. Consequently, it should be adapted to local customs as well as provide tangible short and mid-term benefits for local communities.

Laso Bayas, J. C.; Marohn, C.; Dercon, G.; Dewi, S.; Piepho, H. P.; Joshi, L.; van Noordwijk, M.; Cadisch, G.

2012-04-01

25

Application of remote sensing in coastal change detection after the tsunami event in Indonesia  

Science.gov (United States)

Shoreline mapping and shoreline change detection are critical in many coastal zone applications. This study focuses on applying remote sensing technology to identify and assess coastal changes in the Banda Aceh, Indonesia. Major changes to land cover were found along the coastal line. Using remote sensing data to detect coastal line change requires high spatial resolution data. In this study, two high spatial data with 30 meter resolution of Landsat TM images captured before and after the Tsunami event were acquired for this purpose. The two satellite images was overlain and compared with pre-Tsunami imagery and with after Tsunami. The two Landsat TM images also were used to generate land cover classification maps for the 24 December 2004 and 27 March 2005, before and after the Tsunami event respectively. The standard supervised classifier was performed to the satellite images such as the Maximum Likelihood, Minimum Distance-to-mean and Parallelepiped. High overall accuracy (>80%) and Kappa coefficient (>0.80) was achieved by the Maximum Likelihood classifier in this study. Estimation of the damage areas between the two dated was estimated from the different between the two classified land cover maps. Visible damage could be seen in either before and after image pair. The visible damage land areas were determined and draw out using the polygon tool included in the PCI Geomatica image processing software. The final set of polygons containing the major changes in the coastal line. An overview of the coastal line changes using Landsat TM images is also presented in this study. This study provided useful information that helps local decision makers make better plan and land management choices.

Lim, H. S.; MatJafri, M. Z.; Abdullah, K.; Saleh, N. Mohd.; Surbakti, M. S.

2008-10-01

26

Current issues on PRA regarding seismic and tsunami events at multiunits and sites based on lessons leaned from Tohoku earthquake/tsunami  

Energy Technology Data Exchange (ETDEWEB)

The Tohoku earthquake (Mw9.0) occurred on March 11, 2011 and caused a large tsunami. The Fukushima Dai-ichi NPP (F1-NPP) were overwhelmed by the tsunami and core damage occurred. This paper describes the overview of F1-NPP accident and the usability of tsunami PRA at Tohoku earthquake. The paper makes reference to the following current issues: influence on seismic hazard of gigantic aftershocks and triggered earthquakes, concepts for evaluating core damage frequency considering common cause failure with correlation coefficient against seismic event at multi units and sites, and concepts of 'seismic-tsunami PSA' considering a combination of seismic motion and tsunami effects.

Ebisawa, Katsumi; Fujita, Masatoshi; Iwabuchi, Yoko; Sugino, Hideharu [Japan Nuclear Energy Safety Organization, Tokyo (Japan)

2012-06-15

27

Tsunamis  

Science.gov (United States)

... Clinical Guidance for Carbon Monoxide Poisoning CO Poisoning: Flyers and Educational Materials Clean Up Fact Sheet: Clean ... and Health Concerns Frequently Asked Questions (NOAA) Tsunamis (EPA) Information for Specific Groups CDC's Traveler’s Health website ...

28

GEODYNAMICS OF NAZCA RIDGE’S OBLIQUE SUBDUCTION AND MIGRATION - IMPLICATIONS FOR TSUNAMI GENERATION ALONG CENTRAL AND SOUTHERN PERU: Earthquake and Tsunami of 23 June 2001  

Directory of Open Access Journals (Sweden)

Full Text Available Peru is in a region of considerable geologic and seismic complexity. Thrust faulting along the boundary where the Nazca plate subducts beneath the South American continent has created three distinct seismic zones. The angle of subduction of the Nazca oceanic plate beneath the South American plate is not uniform along the entire segment of the Peru-Chile Trench. Furthermore, subduction is affected by buoyancy forces of the bounding oceanic ridges and fractures - such as the Mendana Fracture Zone (MFZ to the North and the Nazca Ridge to the South. This narrow zone is characterized by shallow earthquakes that can generate destructive tsunamis of varied intensities. The present study examines the significance of Nazca Ridge’s oblique subduction and migration to the seismicity of Central/Southern Peru and to tsunami generation. The large tsunamigenic earthquake of 23 June 2001 is presented as a case study. This event generated a destructive, local tsunami that struck Peru’s southern coasts with waves ranging from 3 to 4.6 meters (10-15 feet and inland inundation that ranged from 1 to 3 km. In order to understand the near and far-field tsunamigenic efficiency of events along Central/Southern Peru and the significance of Nazca Ridge’s oblique subduction, the present study examines further the geologic structure of the region and this quake’s moment tensor analysis, energy release, fault rupture and the spatial distribution of aftershocks. Tsunami source mechanism characteristics for this event are presented, as inferred from seismic intensities, energy releases, fault plane solutions and the use of empirical relationships. The study concludes that the segment of subduction and faulting paralleling the Peru-Chile Trench from about 150 to 180 South, as well as the obliquity of convergent tectonic plate collision in this region, may be the reason for shorter rupture lengths of major earthquakes and the generation of only local destructive tsunamis.

George Pararas-Carayannis

2012-01-01

29

ASSESSMENT OF POTENTIAL TSUNAMI GENERATION IN CHINA'S BOHAI SEA FROM DIRECT GEOTECTONIC AND COLLATERAL SOURCE MECHANISMS  

Directory of Open Access Journals (Sweden)

Full Text Available The Bohai Sea borders northeastern China's most populous and highest economic valuecoastal areas where several megacities are located. Critical infrastructure facilities exist or areunder construction, including a nuclear power plant and super port facilities. Large reserves of oilhave been discovered and a number of offshore oil platforms have been built. The extent ofdevelopment along coastal areas requires a better assessment of potential tsunami risks. Althoughtsunamis do not pose as much of a threat as earthquakes in this region, locally destructive tsunamishave been generated in the past and future events could have significant impacts on coastalpopulations and China's economy, particularly because most of the development has taken place inlow-lying regions, including river deltas. The present study examines the geotectonics of the Bohaibasin region, the impact of past historical events, and the potential for local tsunami generationfrom a variety of direct and collateral source mechanisms triggered by intra plate earthquakes.More specifically, the present study examines: amajor active faults bounding the Bohai Basin; bthe resulting crustal deformation patterns of tectonic structures that have resulted in catastrophicearthquakes in recent years; c the basin-wide extension - with local inversion - extending into theBohai Sea that generated tsunamigenic earthquakes in 1888 and 1969; and d deformational futureseismic events with the potential to generate local tsunamis directly or by collateral mechanisms offolding, en-echelon bookshelf failures, or from destabilization/dissociation of structuralaccumulations of gas hydrate deposits within the basin's thick sedimentary stratigraphic layers.

G. Pararas Carayannis

2009-01-01

30

Tsunami Generated by a Two-Phase Submarine Debris Flow  

Science.gov (United States)

The general two-phase debris flow model proposed by Pudasaini (2011) is employed to study subaerial and submarine debris flows, and the tsunami generated by the debris impact at lakes and oceans. The model includes several essential physical aspects, including Mohr-Coulomb plasticity for the solid stress, while the fluid stress is modelled as a solid volume fraction gradient enhanced non-Newtonian viscous stress. The generalized interfacial momentum transfer includes the viscous drag, buoyancy, and the virtual mass. The generalized drag covers both the solid-like and fluid-like contributions, and can be applied to linear to quadratic drags. Strong couplings exist between the solid and the fluid momentum transfer. The advantage of the real two-phase debris flow model over classical single-phase or quasi-two-phase models is that by considering the solid (and/or the fluid) volume fraction appropriately, the initial mass can be divided into several (even mutually disjoint) parts; a dry (landslide or rock slide), a fluid (water or muddy water; e.g., dams, rivers), and a general debris mixture material as needed in real flow simulations. This offers a unique and innovative opportunity within a single framework to simultaneously simulate (a) the sliding debris (or landslide), (b) the water lake or ocean, (c) the debris impact at the lake or ocean, (d) tsunami generation and propagation, (e) mixing and separation between the solid and the fluid phases, and (f) sediment transport and deposition process in the bathymetric surface. The new model is applied to two-phase subaerial and submarine debris flows. Benchmark numerical simulations reveal that the dynamics of the debris impact induced tsunamis are fundamentally different than the tsunami generated by pure rock avalanche and landslides. Special attention is paid to study the basic features of the debris impact to the mountain lakes or oceans. This includes the generation, amplification and propagation of the multiple strong and bore-type tsunami waves and run-ups in the coastal lines, and debris slide and deposition at the bottom floor. Strong debris shock waves are generated that travel upstream. Once the debris supply ceases, the shock front is diffused. The model analysis also includes mixing and separation of phases, including inter-phase mass and momentum exchanges and generation and interactions of solid and fluid waves. The state of the solid volume fraction governs the evolution of the fluid extra stress and thus effectively dominates the entire flow dynamics. So, the actual knowledge of the solid volume fraction is essential for the prediction of the turbidity currents, sediment transport and deposition in the subaerial and submarine environments. Applications of this model include (i) the sediment transport on hill slopes, river streams, hydraulic channels (e.g., hydropower dams and plants); lakes, fjords, coastal lines, and aquatic ecology; and (ii) submarine debris impact and the rupture of fiber optic, submarine cables and pipelines in ocean floor, and damage to offshore drilling platforms. The Phase-Froude numbers (the solid and fluid Froude numbers) are introduced that change drastically as the debris mass hits the fluid dam. The Phase-Froude numbers can be subcritical or super-critical, suggesting that the tsunami may be following or preceding the wave generating submarine slide and thus enhancing or reducing the tsunami waves. It is observed that the submarine debris front speed can be faster than the tsunami wave speed. This information can be useful for the early warning strategy in the coastal regions. These findings substantially increase the dynamical understanding of complex multi-phase systems and flows, allowing proper modeling of landslide and debris induced tsunami, the dynamics of turbidity currents and sediment transport, with associated applications in hazard mitigation, geomorphology and sedimentology.

Pudasaini, S. P.

2012-04-01

31

Tsunami modeling of multiple earthquake sources from the 2011 Tohoku event using GeoClaw  

Science.gov (United States)

Determining reliable methods for computing the initial tsunami waveform produced by an earthquake will strengthen the ability of tsunami models to both hindcast and forecast potential tsunami hazards. The dense network of instrumental records of the 2011 Tohoku earthquake- including seismometers, GPS receivers, tide gauges, and DART buoys-enabled an unprecedented number of solutions of the earthquake's rupture pattern to be computed. The Tohoku earthquake thus allows us to investigate how complex earthquake ruptures affect tsunami generation, with the aim of resolving the components of the earthquake rupture that dominate tsunami generation. We investigate differences in the farfield and open ocean tsunami waveforms based on a number of proposed earthquake rupture solutions. We compare tsunami waveforms simulated by the tsunami model GeoClaw at a number of locations, including DART buoys in the NW Pacific and tide gauges in California. GeoClaw is a finite volume numerical model using shallow-water-wave equations and adaptive-grid refinement to simulate tsunami waves across bathymetry and onto topography. Our earthquake input files are generated by combining the seafloor deformation of multiple subfaults as predicted by Okada's equations. GeoClaw is an open source code available at http://www.clawpack.org/geoclaw/ The initial seafloor deformation is the key input for comparison between potential tsunami sources and actual measurements. At the DART buoys closest to the earthquake, the overall wavelengths of simulated tsunami oscillations are very similar for the different earthquake rupture models. The primary differences between simulated tsunamis are the amplitude and wavelength of the initial wave. Sources with extensive rupture perpendicular to strike tend to have a longer initial wavelength than the recorded waveform, while sources with rupture primarily near the trench arrive too early at some of the DART buoys. Tsunami measurements in California, far from the Tohoku earthquake, can also be used to distinguish between sources based on waveform characteristics. In Crescent City, California, resonance in the harbor results in the first six waves being significant, allowing for the comparison of tsunami simulations to a long waveform. Most simulated tsunamis have similar wavelengths and general waveform to the recorded tide gauge observation, though they differ in the timing of the first arrival and the amplitude of the waves. Work to compare simulated tsunamis from multiple sources to tide gauges in other locations is ongoing.

MacInnes, B. T.; Arcos, M. E.; Leveque, R. J.; Gonzalez, F. I.

2011-12-01

32

Catalogue of tsunamis generated in Italy and in Côte d'Azur, France: a step towards a unified catalogue of tsunamis in Europe  

Directory of Open Access Journals (Sweden)

Full Text Available This work presents a catalogue of the tsunamis generated in the seas watering the Italian coasts, including the neighbouring area of Côte d'Azur (France. Events generated far from Italy and affecting the Italian coasts are not taken into account here. The catalogue, that we will also call the Quick-Look Catalog (QLC, is organised in three main sections that are named the Quick-Look Table, the Quick-Look Accounts File and the References File, having the respective abbreviations of QLT, QLAF and RF. The QLT is a synoptic table containing the relevant information available for each event, one table row corresponding to one event. More details are provided in the QLAF, where each event is dedicated a specific subsection: here the description of the tsunami includes all essential aspects that are suitably referenced and is preceded by a concise report concerning the tsunami cause. Lastly, the RF is the list of all the papers and publications quoted in the QLT and QLAF. Notice that efforts have been made to qualify each event by means of contemporaneous sources, although later sources and indirect sources, such as existing catalogues, have not been disregarded. Besides, specific recent studies on the events have been given special mention. In this work some general review of the past catalogues of tsunamis and of recent trends in the subject are expressed. Particularly, great attention is given to analysing the CFB of the Italian tsunamis due to Caputo and his collaborators (Caputo and Faita, 1984; Bedosti and Caputo, 1986, the acronym being formed by the ordered initials of the authors. Motivations clarifying the need for a new catalogue of the Italian tsunamis are illustrated circumstantially. The very different philosophies that are at the basis of the CFB and of the present QLC lead to quite diverse products and results, that are summarised by a table where the events included in the CFB and in the QLC are compared: the net effect of the rigorous scrutiny applied to the sources and of the coherent analysis applied to the data is that only 67 events are included in the QLC, which is about one third of the events that can be counted in the CFB.

A. Maramai

1996-06-01

33

TSUNAMIS OF THE ARABIAN PENINSULA A GUIDE OF HISTORIC EVENTS  

Directory of Open Access Journals (Sweden)

Full Text Available The Arabian Peninsula has been affected by tsunamis in the past. The Peninsula is bounded by the Persian Gulf on its northeast side, the Red Sea on its west side, and the Arabian Sea, the Gulf of Aden, and the Indian Ocean to its east and south. Each of these areas is very different geographically, tectonically, and bathymetrically.Only two, localized tsunamis have been recorded in the Red Sea and one, doubtful, tsunami in the Persian Gulf. Almost all of the recorded tsunamis along the Arabian Peninsula have occurred on its eastern and southern edge, some, such as the one formed by the 1945 Makran earthquake, were extremely destructive. The Indian Ocean is the most likely source area for future destructive tsunamis that would impact the Arabian Peninsula.

Benjamin R. Jordan

2008-01-01

34

Impact of a tsunami generated at the Lesser Antilles subduction zone on the Northern Atlantic Ocean coastlines  

Science.gov (United States)

On 11 March 2011, a Mw ~ 9.0 megathrust earthquake occurred off the coast of Tohoku, triggering a catastrophic tsunami reaching heights of 10 m and more in some places and resulting in lots of casualties and destructions. It is one of a handful of catastrophic tsunamis having occurred during the last decade, following the 2004 Indonesian tsunami, and leading to the preparation of tsunami warning systems and evacuation plans all around the world. In the Atlantic Ocean, which has been struck by two certified transoceanic tsunamis over the past centuries (the 1755 "Lisbon" and 1929 Grand Banks events), a warning system is also under discussion, especially for what concerns potential tsunamigenic sources off Iberian Peninsula. In addition, the Lesser Antilles subduction zone is also potentially able to generate powerful megathrust ruptures as the 8 February 1843 Mw ~ 8.0/8.5 earthquake, that could trigger devastating tsunamis propagating across the Northern Atlantic Ocean. The question is in which conditions these tsunamis could be able to reach the Oceanic Islands as well as the eastern shores of the Atlantic Ocean, and what could be the estimated times to react and wave heights to expect? This paper attempts to answer those questions through the use of numerical modelings and recent research results about the Lesser Antilles ability to produce megathrust earthquakes.

Roger, J.; Frère, A.; Hébert, H.

2014-07-01

35

Impact-generated Tsunamis: An Over-rated Hazard  

Science.gov (United States)

A number of authors have suggested that oceanic waves (tsunami) created by the impact of relatively small asteroids into the Earth's oceans might cause widespread devastation to coastal cities. If correct, this suggests that asteroids > 100 m in diameter may pose a serious hazard to humanity and could require a substantial expansion of the current efforts to identify earth-crossing asteroids > 1 km in diameter. The debate on this hazard was recently altered by the release of a document previously inaccessible to the scientific community. In 1968 the US Office of Naval Research commissioned a summary of several decades of research into the hazard proposed by waves generated by nuclear explosions in the ocean. Authored by tsunami expert William Van Dorn, this 173-page report entitled Handbook of Explosion-Generated Water Waves affords new insight into the process of impact wave formation, propagation, and run up onto the shoreline.

Melosh, H. J.

2003-01-01

36

Tsunami  

Science.gov (United States)

This lesson plan is part of the DiscoverySchool.com lesson plan library for grades 6-8. It focuses on tsunamis and the destruction they can cause. Students design experiments to view the two types of tsunamis (fjord and ocean) and view the different wave patterns associated with each. Included are objectives, materials, procedures, discussion questions, evaluation ideas, and vocabulary. There are videos available to order which complement this lesson, and links to teaching tools for making custom quizzes, worksheets, puzzles and lesson plans.

Hurstcalderone, Susan

37

OCEAN-WIDE TSUNAMIS, MAGNITUDE THRESHOLDS, AND 1946 TYPE EVENTS  

Directory of Open Access Journals (Sweden)

Full Text Available An analysis of magnitudes and runups in Hawaii for more than 200 tsunamigenic earthquakes along the margins of the Pacific reveals that all of the earthquakes with moment magnitudes of 8.6 or greater produced significant Pacific-wide tsunamis. Such findings can be used as a basis for early warnings of significant ocean-wide tsunamis as a supplement to, or in the absence of, more comprehensive data from other sources. Additional analysis of magnitude and runup data suggests that 1946 type earthquakes and tsunamis may be more common than previously believed.

Daniel A. Walker

2005-01-01

38

Numerical modelling of tsunami generation by deformable submarine slides using mesh adaptivity  

Science.gov (United States)

Tsunamis generated by submarine slides are often under considered in comparison to earthquake generated tsunami, despite several recent examples. Tsunamigenic slides have generated waves that have caused significant damage and loss of life, for example the 1998 Papua New Guinea submarine mass failure resulted in a tsunami that devastated coastal villages and killed over 2,100 people. Numerical simulations of submarine slide generated waves can help us understand the nature of the waves that are generated, and identify the important factors in determining wave characteristics. There have not been many studies of tsunami generation by deformable submarine slides, largely because of the complexities and computational expense involved in modelling these large scale events. At large, real world, scales modelling of tsunami waves by the generation of slides is computationally challenging. Fluidity is an open source finite element code that is ideally suited to tackle this type of problem as it uses unstructured, adaptive meshes, which help to reduce the computational expense without losing accuracy in the results. Adaptive meshes change topology and resolution based on the current simulation state and as such can focus or reduce resolution when and where it is required. The model also allows a number of different numerical approaches to be taken to simulate the same problem within the same numerical framework. In this example we use multi-material approach, with both two materials (slide and water) and three materials (slide, water and air), alongside a density-driven sediment model approach. We will present results of validating Fluidity against benchmarks from experimental and other numerical studies, at different scales, for deformable underwater slides, and consider the utility of mesh adaptivity. We show good agreement to both laboratory results and other numerical models, both with a fixed mesh and a dynamically adaptive mesh, tracking important features of the slide geometry as the simulation progresses. This is the first step in being able to simulate both the wave initiation, propagation, and inundation within the same numerical model at real-world scales for submarine slide generated tsunamis.

Smith, Rebecca; Parkinson, Samuel; Hill, Jon; Collins, Gareth; Piggott, Matthew

2014-05-01

39

Tsunami Generation and Propagation by 3D deformable Landslides and Application to Scenarios  

Science.gov (United States)

Tsunamis generated by landslides and volcano flank collapse account for some of the most catastrophic natural disasters recorded and can be particularly devastative in the near field region due to locally high wave amplitudes and runup. The events of 1958 Lituya Bay, 1963 Vajont reservoir, 1980 Spirit Lake, 2002 Stromboli and 2010 Haiti demonstrate the danger of tsunamis generated by landslides or volcano flank collapses. Unfortunately critical field data from these events is lacking. Source and runup scenarios based on real world events are physically modeled using generalized Froude similarity in the three dimensional NEES tsunami wave basin at Oregon State University. A novel pneumatic landslide tsunami generator (LTG) was deployed to simulate landslides with varying geometry and kinematics. The bathymetric and topographic scenarios tested with the LTG are the basin-wide propagation and runup, fjord, curved headland fjord and a conical island setting representing a landslide off an island or a volcano flank collapse. The LTG consists of a sliding box filled with 1,350 kg of landslide material which is accelerated by means of four pneumatic pistons down a 2H:1V slope. The landslide is launched from the sliding box and continues to accelerate by gravitational forces up to velocities of 5 m/s. The landslide Froude number at impact with the water is in the range 1 camera recordings. The landslide deposit is measured on the basin floor with a multiple transducer acoustic array (MTA). Landslide surface reconstruction and kinematics are determined with a stereo particle image velocimetry (PIV) system. Wave runup is recorded with resistance wave gauges along the slope and verified with video image processing. The measured landslide and wave parameters are compared between the planar hill slope used in various scenarios and the convex hill slope of the conical island. The energy conversion rates from the landslide motion to the wave train is quantified for the planar and convex hill slopes. The wave runup data on the opposing headland is analyzed and evaluated with wave theories. A method to predict the maximum wave runup on an opposing headland using nondimensional landslide, water body and bathymetric parameters is derived. The measured landslide and tsunami data serve to validate and advance three-dimensional numerical landslide tsunami prediction models.

McFall, Brian C.; Fritz, Hermann M.

2014-05-01

40

Wroclaw neutrino event generator  

Science.gov (United States)

A neutrino event generator developed by the Wroclaw Neutrino Group is described. The physical models included in the generator are discussed and illustrated with the results of simulations. The considered processes are quasi-elastic scattering and pion production modelled by combining the ? resonance excitation and deep inelastic scattering.

Nowak, J. A.

2006-10-01

 
 
 
 
41

An approximate method of short-term tsunami forecast and the hindcasting of some recent events  

Directory of Open Access Journals (Sweden)

Full Text Available The paper presents a method for a short-term tsunami forecast based on sea level data from remote sites. This method is based on Green's function for the wave equation possessing the fundamental property of symmetry. This property is well known in acoustics and seismology as the reciprocity principle. Some applications of this principle on tsunami research are considered in the current study. Simple relationships and estimated transfer functions enabled us to simulate tsunami waveforms for any selected oceanic point based only on the source location and sea level data from a remote reference site. The important advantage of this method is that it is irrespective of the actual source mechanism (seismic, submarine landslide or other phenomena. The method was successfully applied to hindcast several recent tsunamis observed in the Northwest Pacific. The locations of the earthquake epicenters and the tsunami records from one of the NOAA DART sites were used as inputs for the modelling, while tsunami observations at other DART sites were used to verify the model. Tsunami waveforms for the 2006, 2007 and 2009 earthquake events near Simushir Island were simulated and found to be in good agreement with the observations. The correlation coefficients between the predicted and observed tsunami waveforms were from 0.50 to 0.85. Thus, the proposed method can be effectively used to simulate tsunami waveforms for the entire ocean and also for both regional and local tsunami warning services, assuming that they have access to the real-time sea level data from DART stations.

Yu. P. Korolev

2011-11-01

42

Tsunami wave generation by the eruption of underwater volcano  

Directory of Open Access Journals (Sweden)

Full Text Available Eruption of volcanoes represents one of important origins of tsunami waves and is responsible for most catastrophic tsunami (Krakatau, 1883; Thira, BC. The products of volcano eruption include solids, liquids (lava and gases. The present article presents hydrodynamic model of relatively slow process of eruption, with domination of liquids. The process of underwater eruption of lava causes the disturbance of ocean free surface. The standard formulation of hydrodynamic problem for incompressible fluid in cylindrically symmetric layer of with rigid bottom and free surface with local hydrodynamic source (volcano is used. This problem is solved by constructing Green function using methodology of Sretenskij. The solution is obtained in the form of an integral and depends on the dynamics of eruption. Real data show that some volcanoes can erupt several millions of tons of lava during several dozens of seconds (Bezimjannij, Kamchatka. The long waves are more efficiently generated by larger T: these tsunamis can have smaller initial perturbations of free surface, but the waves are long and can transmit their energy over longer distances.

Y. Egorov

2007-01-01

43

The 30 December 2002 landslide-induced tsunamis in Stromboli: sequence of the events reconstructed from the eyewitness accounts  

Directory of Open Access Journals (Sweden)

Full Text Available On 30 December 2002 the coast of the volcanic island of Stromboli, in the Tyrrhenian sea, Italy, was attacked by two tsunamis generated by landslides that took place on the north-west flank of the volcano. The landslides and the tsunamis represented the most impressive and threatening episodes of a strong effusive eruption, started on 28 December from a new vent which opened close to the north-east crater of the volcano. In spite of the intensified monitoring carried out in response to the eruption, the landslides and the ensuing tsunamis were not foreseen, and the available instrumental data are insufficient to allow a precise reconstruction of the sequence of the events. The seismic network recorded two main landslides along the steep slope of Sciara del Fuoco, with onset around 13:15 and 13:23 local time (GMT+1. The tsunamis were the direct consequence of the mass movements. Three main post-event surveys helped make assessment on the wave impact on the coast. In this paper the attention is focussed on the accounts of the eye-witnesses, that help us clarify and understand what happened. People in the source area (Sciara del Fuoco reported a small-volume subaerial slide taking place first, then a sharp cut forming in the sea water down to the sea floor (about 10–20 m deep and propagating almost parallel to the coastline, be concomitantly associated with a sea retreat and a subsequent sea advance. It is suggested here that the cut was the effect of a large submarine landslide that detached from very close to the coast and produced the 13:15 signal in the recorded seismograms. The second, mostly subaerial, slump was observed to slide down 7–8 min later and to excite a train of waves some distance offshore. Not all the witnesses realised that two distinct tsunamis occurred. The tsunami period was probably in the order of 100 s, but shorter period crests were seen to travel on the top of the long-period waves by several persons. The duration of each tsunami was appreciated to be around 5–7 min. It is difficult to ascertain which tsunami was the largest, since there is no full agreement among the observers, but certainly by accounts both were characterised by large destructive waves.

S. Tinti

2005-01-01

44

Identification of earthquakes that generate tsunamis in Java and Nusa Tenggara using rupture duration analysis  

Science.gov (United States)

Java and Nusa Tenggara are the tectonically active of Sunda arc. This study discuss the rupture duration as a manifestation of the power of earthquake-generated tsunami. We use the teleseismic (30° - 90°) body waves with high-frequency energy Seismometer is from IRIS network as amount 206 broadband units. We applied the Butterworth high bandpass (1 - 2 Hz) filtered. The arrival and travel times started from wave phase of P - PP which based on Jeffrey Bullens table with TauP program. The results are that the June 2, 1994 Banyuwangi and the July 17, 2006 Pangandaran earthquakes identified as tsunami earthquakes with long rupture duration (To > 100 second), medium magnitude (7.6 50 second which depend on its magnitude. Those events are located far from the trench.

Pribadi, S.; Puspito, N. T.; Yudistira, T.; Afnimar, Ibrahim, G.; Laksono, B. I.; Adnan, Z.

2014-09-01

45

Displaced Water Volume, Potential Energy of Initial Elevation, and Tsunami Intensity: Analysis of Recent Tsunami Events  

Science.gov (United States)

We consider recent ocean-bottom earthquakes for which detailed slip distribution data are available. Using these data and the Okada formulae, we calculate the vector fields of co-seismic bottom deformations, which allow us to determine the displaced water volume and the potential energy of initial elevation of the tsunami source. It is shown that, in the majority of cases, the horizontal components of bottom deformation provide an additional contribution to the displaced water volume and virtually never diminish the contribution of the vertical component. The absolute value of the relative contribution of the horizontal components of bottom deformation to the displaced volume varies from 0.07 to 55 %, on average amounting to 14 %. The displaced volume and the energy of initial elevation (tsunami energy) are examined as functions of the moment magnitude, and the relevant regressions (least-squares fits) are derived. The obtained relationships exhibit good correspondence with the theoretical upper limits that had been obtained under the assumption of uniform slip distribution along a rectangular fault. Tsunami energy calculated on the basis of finite fault model data is compared with the earthquake energy determined from the energy-magnitude relationship by Kanamori. It is shown that tsunami takes from 0.001 to 0.34 % of the earthquake energy, and on average 0.04 %. Finally, we analyze the Soloviev-Imamura tsunami intensity as a function of the following three quantities: (1) the moment magnitude, (2) the decimal logarithm of the absolute value of displaced volume, and (3) the decimal logarithm of the potential energy of initial elevation. The first dependence exhibits rather poor correlation, whereas the second and third dependences demonstrate noticeably higher correlation coefficients. This gives us grounds to suggest considering the displaced volume and the energy of initial elevation as measures of the tsunamigenic potential of an earthquake.

Nosov, Mikhail A.; Bolshakova, Anna V.; Kolesov, Sergey V.

2013-11-01

46

Event Generator Comparisons  

International Nuclear Information System (INIS)

In this note we compare four neutrino event generators that are widely used in the neutrino community. In doing so we will attempt to indicate the uncertainty in neutrino simulations due to different model choices in areas where a clear theoretical picture is lacking, and identify areas where further theoretical and experimental work would be beneficial

47

Event Generator Comparisons  

Energy Technology Data Exchange (ETDEWEB)

In this note we compare four neutrino event generators that are widely used in the neutrino community. In doing so we will attempt to indicate the uncertainty in neutrino simulations due to different model choices in areas where a clear theoretical picture is lacking, and identify areas where further theoretical and experimental work would be beneficial.

Gallagher, Hugh [Tufts University, Medford, MA, 02176 (United States)]. E-mail: gallag@minos.phy.tufts.edu; Casper, Dave [University of California, Irvine, CA 92697 (United States)]. E-mail: dcasper@uci.edu; Hayato, Yoshinari [Institute of Nuclear and Particle Studies, KEK 1-1 Oho, Tsukuba, Ibaraki 305-0801 (Japan)]. E-mail: yoshinari.hayato@kek.jp; Sala, Paola [CERN, CH-1211 Geneva 23 (Switzerland)]. E-mail: paola.sala@cern.ch

2005-02-15

48

Tsunami Database  

Science.gov (United States)

The Tsunami Database is a global digital database containing information on more than 2000 tsunamis maintained by the National Geophysical Data Center. This is an interactive site; the user is asked to enter search parameters such as date, latitude and longitude, cause of the tsunami - earthquake, landslide, volcano, or all combined - magnitude, and death. Information is then generated on tsunamis that match that data. The National Geophysical Data Center also maintains an historic slide set collection of tsunami damage.

49

Double jeopardy: Concurrent arrival of the 2004 Sumatra tsunami and storm-generated waves on the Atlantic coast of the United States and Canada  

Science.gov (United States)

A detailed analysis of over one hundred tide gauge records from the Atlantic coast of North America reveals that the arrival of the 26 December 2004 Sumatra tsunami on this coast coincided with the presence of tsunami-like waves being generated by a major storm tracking northward along the eastern seaboard of the United States. According to the tide gauge records, waves from the two events coalesced along the shores of Maine and Nova Scotia on 27 December where they produced damaging waves with heights in excess of 1 m. Tsunami waves were identified in almost all outer tide gauges from Florida to Nova Scotia with maximum tsunami heights for the northern regions estimated to be 32-39 cm. In the south, maximum tsunami wave heights were in the range of 15 to 33 cm.

Thomson, Richard E.; Rabinovich, Alexander B.; Krassovski, Maxim V.

2007-08-01

50

Potential for tsunami generation by submarine slope failures along the western Great Bahama Bank  

Science.gov (United States)

Multibeam and seismic data reveal repeated slope failures at various scales along the western slope of Great Bahama Bank. In addition, creeping and incipient slump scars indicate slope instabilities that will lead to large-scale slope failures in the near future. To assess the potential of tsunami generation by these slope failures several tsunami scenarios have been constructed and simulated numerically for the Straits of Florida. They are based on the estimated volume and nature of a potential landslide, and failure scenarios of the known scars and mass transport complexes (MTC). During the 2010 Carambar cruise four connected scars with widths of 2.0, 2.2, 3.7 and 1.6 km and lengths of 3.0, 1.4, 3.2 and 3.0 km, respectively, were identified. In the Scenario A, the mass 1.18 km3 of the largest of the four failures was calculated. In Scenario B it is assumed that all scars were generated in one event producing a large MTC with an initial failure mass 3.42 km3. Three different terminal velocities for the failure masses were used; i.e. 20 m/s, 50 m/s and 100 m/s. The numerical model is based on the non-hydrostatic wave model NHWAVE developed at the Center for Applied Coastal Research at the University of Delaware. Initial wave heights generated are discussed in terms of terminal landslide velocity, failure volume, and outrun distance. The results show that for scenario A within one minute after the failure event a wave height up to 1 m is generated. For scenario B initial wave heights from 1 up to 2 m can be expected. The waves propagate across the entire Straits of Florida impacting the coastline for about 150 km. An 80 km long scar with abundant creeping features in the downslope area is a potential massive slope failure. If released in one event the mass would be 24 km3. A catastrophic release would generate an initial tsunami wave height of 2.5 up to 4 m with a possible major impact on both sides of the Straits. The modeling demonstrates that the generation of tsunamis by slope failure in a tectonically inactive area can cause a potential hazard in the densely populated urban areas of south Florida and the Keys.

Schnyder, J. S.; Kirby, J. T.; Shi, F.; Tehranirad, B.; Eberli, G. P.; Mulder, T.; Ducassou, E.

2013-12-01

51

Modeling Ruptures and Tsunamis That May Follow Event of September 12  

Science.gov (United States)

The seismic series of the 12-13 September near the Padang/Bengkulu region in Western Sumatra, Indonesia, emerged to, but did not rupture the three locked patches at the subduction plate interface as recently derived from geodetic and paleogeodetic studies (Chlieh et al., 2007), likely increasing probability of the next giant earthquake off Padang. Future earthquake, when rupturing all of the three locked patches, may reach a magnitude of about M=9 and repeat giant historical event of 1797 and partly that of 1833 followed by severe tsunamis. We have modeled possible earthquake and tsunami scenarios assuming future ruptures coinciding with each of the presently locked patches. Our modeling is performed in a framework of the currently developed German- Indonesian Tsunami Early Warning System (GITEWS). Resulting tsunami wave height in Padang is very sensitive to the location of the ruptured patch. The shallow patch under the Siberut island and the deep patch just off Padang, both result in M=8.4 earthquakes. However, the latter rupture would result in considerably shorter arrival time and in more than 5 times higher run-up in Padang. We show that GPS stations at islands and at Padang can be used to estimate rupture parameters and to predict tsunami heights just after the earthquake. Our modeling also demonstrates that historical records about the 1797 tsunami are more consistent with the simultaneous rupturing of both the shallow and deep patches off Padang.

Babeyko, A. Y.; Sobolev, S. V.; Harig, S.; Androsov, A.

2007-12-01

52

The human impact of tsunamis: a historical review of events 1900-2009 and systematic literature review.  

Science.gov (United States)

Introduction. Although rare, tsunamis have the potential to cause considerable loss of life and injury as well as widespread damage to the natural and built environments. The objectives of this review were to describe the impact of tsunamis on human populations in terms of mortality, injury, and displacement and, to the extent possible, identify risk factors associated with these outcomes. This is one of five reviews on the human impact of natural disasters. Methods. Data on the impact of tsunamis were compiled using two methods, a historical review from 1900 to mid 2009 of tsunami events from multiple databases and a systematic literature review to October 2012 of publications. Analysis included descriptive statistics and bivariate tests for associations between tsunami mortality and characteristics using STATA 11. Findings. There were 255,195 deaths (range 252,619-275,784) and 48,462 injuries (range 45,466-51,457) as a result of tsunamis from 1900 to 2009. The majority of deaths (89%) and injuries reported during this time period were attributed to a single event -the 2004 Indian Ocean tsunami. Findings from the systematic literature review indicate that the primary cause of tsunami-related mortality is drowning, and that females, children and the elderly are at increased mortality risk. The few studies that reported on tsunami-related injury suggest that males and young adults are at increased injury-risk. Conclusions. Early warning systems may help mitigate tsunami-related loss of life. PMID:23857277

Doocy, Shannon; Daniels, Amy; Dick, Anna; Kirsch, Thomas D

2013-01-01

53

Physical Modeling of Landslide Generated Tsunamis and the 50th Anniversary of the Vajont Dam Disaster  

Science.gov (United States)

The Vajont river is an affluent of the Piave River located in the Dolomite Alps of the Veneto Region, about 100km north of Venice. A 265.5 m high double curved arch dam was built across a V-shaped gorge creating a reservoir with a maximum storage capacity of 0.169 km3. A maximum water depth of 250 m was reached by early September 1963 during the third filling attempt of the reservoir, but as creeping on the southern flank increased the third reservoir draw down was initiated. By October 9, 1963 the water depth was lowered to 240m as the southern flank of Vajont reservoir catastrophically collapsed on a length of more than 2km. Collapse occurred during reservoir drawdown in a final attempt to reduce flank creeping and the reservoir was only about two-thirds full. The partially submerged rockslide with a volume of 0.24 km3 penetrated into the reservoir at velocities up to 30 m/s. The wave runup in direct prolongation of slide axis reached the lowest houses of Casso 270m above reservoir level before impact corresponding to 245m above dam crest (Müller, 1964). The rockslide deposit came within 50m of the left abutment and towers up to 140m above the dam crest. The lateral spreading of the surge overtopped the dam crest by more than 100m. The thin arch dam withstood the overtopping and sustained no damage to the structural shell and the abutments. The flood wave dropped more than 500m down the Vajont gorge and into the Piave Valley causing utter destruction to the villages of Longarone, Pirago, Villanova, Rivalta and Fae. More than 2000 persons perished. The Vajont disaster highlights an extreme landslide tsunami event in the narrowly confined water body of a reservoir. Landslide tsunami hazards exist even in areas not exposed to tectonic tsunamis. Source and runup scenarios based on real world events are physically modeled in the three dimensional NEES tsunami wave basin (TWB) at Oregon State University (OSU). A novel pneumatic landslide tsunami generator (LTG) was deployed to simulate landslides with varying geometry and kinematics. The LTG consists of a sliding box filled with up to 1,350 kg of naturally rounded river gravel which is accelerated by means of four pneumatic pistons down the 2H: 1V slope, launching the granular landslide towards the water at velocities of up to 5 m/s. Topographical and bathymetric features can greatly affect wave characteristics and runup heights. Landslide tsunamis are studied in different topographic and bathymetric configurations: far field propagation and runup, a narrow fjord and curved headland configurations, and a conical island setting representing landslides off an island or a volcanic flank collapse. Water surface elevations were measured using an array of resistance wave gauges. The granulate landslide shape and front velocity were measured using above and underwater cameras. Three-dimensional landslide surfaces with surface velocities were reconstruction using a stereo particle image velocimetry (PIV) setup. The speckled pattern on the surface of the granular landslide allows for cross-correlation based PIV analysis. Wave runup was measured with resistance wave gauges along the slope and verified with video image processing. The measured landslide and tsunami data serve to validate and advance 3-dimensional numerical landslide tsunami and prediction models.

McFall, Brian C.; Mohammed, Fahad; Fritz, Hermann M.

2013-04-01

54

A nested-grid Boussinesq-type approach to modelling dispersive propagation and runup of landslide-generated tsunamis  

Directory of Open Access Journals (Sweden)

Full Text Available A tsunami generated by large-volume landslide can propagate across the ocean and flood communities around the basin. The evolution of landslide-generated tsunamis is affected by the effects of frequency dispersion and involves processes of different temporal and spacial scales. In this paper, we develop a numerical approach employing the weakly nonlinear and fully nonlinear Boussinesq-type theories and nested computational grids. The propagation in a large domain is simulated with the weakly nonlinear model in a geographical reference frame. The nearshore wave evolution and runup are computed with the fully nonlinear model. Nested grids are employed to zoom simulations from larger to smaller domains at successively increasing resolutions. The models and the nesting scheme are validated for theoretical analysis, laboratory experiments and a historical tsunami event. By applying this approach, we also investigate the potential tsunami impact on the US east coast due to the possible landslide on La Palma Island. The scenario employed in this study represents an event of extremely low probability.

H. Zhou

2011-10-01

55

Numerical simulation of the 2002 Northern Rhodes Slide (Greece) and evaluation of the generated tsunami  

Science.gov (United States)

Small landslides are very common along the submarine margins, due to steep slopes and continuous material deposition that increment mass instability and supply collapse occurrences, even without earthquake triggering. This kind of events can have relevant consequences when occurring close to the coast, because they are characterized by sudden change of velocity and relevant speed achievement, reflecting into high tsunamigenic potential. This is the case for example of the slide of Rhodes Island (Greece), named Northern Rhodes Slide (NRS), where unusual 3-4 m waves were registered on 24 March 2002, provoking some damage in the coastal stretch of the city of Rhodes (Papadopoulos et al., 2007). The event was not associated with earthquake occurrence, and eyewitnesses supported the hypothesis of a non-seismic source for the tsunami, placed 1 km offshore. Subsequent marine geophysical surveys (Sakellariou et al., 2002) evidenced the presence of several detachment niches at about 300-400 m depth along the northern steep slope, one of which can be considered responsible of the observed tsunami, fitting with the previously mentioned supposition. In this work, that is carried out in the frame of the European funded project NearToWarn, we evaluated the tsunami effects due to the NRS by means of numerical modelling: after having reconstructed the sliding body basing on morphological assumptions (obtaining an esteemed volume of 33 million m3), we simulated the sliding motion through the in-house built code UBO-BLOCK1, adopting a Lagrangian approach and splitting the sliding mass into a "chain" of interacting blocks. This provides the complete dynamics of the landslide, including the shape changes that relevantly influence the tsunami generation. After the application of an intermediate code, accounting for the slide impulse filtering through the water depth, the tsunami propagation in the sea around the island of Rhodes and up to near coasts of Turkey was simulated via the code UBO-TSUFD: this solves numerically the Navier-Stokes equation in the shallow water approximation, adopting a finite difference technique. It was then possible to estimate the most affected coastal stretches and to assess the effects of the NRS generated tsunami, comparing the computed wave heights with the observations. Papadopoulos G.A., Daskalaki E., Fokaefs A. (2007) Tsunamis generated by coastal and submarine landslides in the Mediterranean Sea. In: Lykousis V., Sakellariou D., Locat J. (eds.), Submarine Mass Movements and their Consequences, 415-422, Springer. Sakellariou D., Lykousis V., Rousakis G., Georgiou P. (2002). Slope failure and associated coastal erosion in tectonically active areas: The coastal zone of Rhodes city (Rhodos island) Greece. In: A. Yilmaz (ed.): Oceanography of Eastern Mediterranean and Black Sea, 978-985, Proceedings of the 2nd International Conference Oct. 13-16, TUBITAK Publ., Ankara, Turkey.

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

2013-04-01

56

The Pluto event generator  

International Nuclear Information System (INIS)

Pluto is a Monte-Carlo event generator designed for hadronic interactions from close-to-threshold to intermediate energies, as well as for studies of heavy ion reactions. The package is entirely based on Root, without the need of additional packages, and uses the embedded C++ interpreter of root to control the event production. The package includes realistic models of resonance production by using mass-dependent Breit-Wigner sampling. The calculation of partial and total widths for resonances is taken into account. Particular attention is paid to the electromagnetic decays, motivated by the physics program of HADES. For elementary reactions, angular distributions (e.g. for the primary meson emission) can be attached by the user in a very simple way as well as multi-particle correlations. Hand-made models (which may change all decay parameters) can be included by the user without recompilation using the CINT interpreter. This contribution gives an overview of the technical implementation of the framework and presents examples of the included physics

57

Historic and pre-historic tsunamis in the Mediterranean and its connected seas: a review on documentation, geological signatures, generation mechanisms and coastal impacts  

Science.gov (United States)

The origin of tsunamis in the Mediterranean region and its connected seas is reviewed. A variety of historical documentary sources combined with evidence from on-shore and off-shore geological signatures, geomorphological imprints, observations from selected coastal archaeological sites, as well as from instrumental records, clearly indicate that seismic and non-seismic (e.g. volcanism, landslides) tsunami sources can be found in all the seas of the region. Local, regional and basin-wide tsunamis have been documented. An improved map of 22 tsunamigenic zones and their relative potential for tsunami generation is presented. From west to east, the most tsunamigenic zones are situated offshore SW Iberia, in North Algeria, in the Tyrrhenian Calabria and Messina Straits, in the western and eastern segments of the Hellenic Arc, in Corinth Gulf (Central Greece), in the Levantine Sea off-shore the Dead Sea Transform Fault and in the eastern Marmara Sea. The mean recurrence of large (intensity?8) tsunamis in the entire region is ~90 yrs and in the Mediterranean basin ~102 yrs. However, for most of the historical events it is still doubtful which one was the causative seismic fault and if the tsunami was caused by co-seismic fault dislocation or by earthquake-triggered submarine landslides or by a combined source mechanism (e.g. Lisbon 1755). Instrumentally recorded seismic tsunamis (e.g. Messina 1908, S. Aegean 1956) are still with debatable sources. Calculation of seismic slip slowness factor does not indicate that the 1908 and 1956 events were "tsunami earthquakes". In pre-historical times large tsunamis were caused by volcanic processes in Thera and Etna. A tsunami was supposedly generated in the Holocene by the so-called BIG'95 large submarine landslide in W. Mediterranean. The AD 1650 eruption of the submarine Columbo volcano, off-shore Thera, caused an important tsunami but very little is known about its source mechanism. We concluded that investigating further the tsunami generation mechanisms is of primary importance. Inputs from tsunami numerical modeling and from empirical discrimination criteria for characterizing tsunami sources have been proved particularly effective for recent, well-documented, aseismic landslide tsunamis (1963 Corinth Gulf, 1979 Côte d' Azur, 1999 Izmit Bay, 2002 Stromboli volcano). Since the tsunami generation mechanisms are controlled by a variety of factors, and given that the knowledge of past tsunami activity is the cornerstone for undertaking tsunami risk mitigation actions, future interdisciplinary research efforts on past tsunamis is needed to include: (i) investigation and identification of palaeotsunamis through geological methods in both on-shore and off-shore environments and correlation with the historical record, (ii) better constraints on earthquake and other source parameters and mechanisms, (iii) further development and testing of diagnostic criteria for the source characterization, (iv) drastic improvement of high-resolution bathymetry particularly in the near-shore domain mainly through marine geophysics, as well as of DEM's for coastal topography, and (v) advancement and systematic testing of numerical modeling techniques.

Papadopoulos, Gerassimos; Gràcia, Eulàlia; Urgeles, Roger; Sallares, Valenti; De Martini, Paolo Marco; Pantosti, Daniela; González, Mauricio; Yalciner, Ahmet C.; Mascle, Jean; Sakellariou, Dimitris; Salamon, Amos; Tinti, Stefano; Fokaefs, Anna; Camerlenghi, Angelo; Novikova, Tatyana; Papageorgiou, Antonia

2013-04-01

58

Numerical modelling of tsunami generated by the 1650 eruption of Kolumbo, South Aegean Sea, Greece  

Science.gov (United States)

Historical 1650 tsunami generated by explosion of Kolumbo volcano was investigated. Using nonlinear shallow water equations implemented in COMCOT tsunami modelling package we simulate for the tsunami generation and propagation, and compute the inundation distances inland along the nearby Santorini island. Two tsunamigenic mechanisms are tested. First, we assume a scenario of phreatomagmatic explosion. Eruption is investigated using a model for shallow underwater explosions. A systematic study is performed for explosion energy range between 1014 and 1017~J. Second, we employed a caldera collapse scenario with duration up to 2~h. The first waves hit the coast of Santorini, the most populated island in the area and also the closest one to Kolumbo ( ˜~7~km), in about 3~min. Calculated inundation distances with predicted nearshore waves amplitudes provide insights into possible tsunami impact and help to assess the tsunami hazard for this region.

Ulvrova, M.; Paris, R.; Kelfoun, K.; Nomikou, P.

2013-12-01

59

Catalogue of reported tsunami events in the Adriatic Sea (from 58 B.C. to 1979 A.D.)  

International Nuclear Information System (INIS)

This catalogue furnishes a collection of the reported tsunamis within the Adriatic, i.e. Italian coasts from the Strait of Otranto to the gulf of Trieste, the coasts of Slovenia, Croatia, Serbia, Montenegro and Albania. The events are obtained by the cross-comparison between many existing catalogues, in order to extract all the available reported ones. For each tsunamigenic event, when available in a catalogue, we report: origin time, location, macroseismic intensity, magnitude and the areas (within Adriatic basin) where tsunamis have been reported. In the last column of the table, all the catalogues in which some information of the event (earthquake and tsunami) has been found, are listed; bold letters indicate the basic catalogue for that event (i.e. the catalogue where the origin time has been taken from). Since in the present catalogue more attention is paid to the tsunamis than to the seismic events, the bold reference indicates always the tsunami-catalogue, and not the seismic ones, when contemporarily available. For some events there are no records of a related tsunami (they are labelled as N.A.T.R.= not available tsunami report) but they are included since their location and magnitude suggest a tsunamigenic potential. (author)

60

The Gondola slide generated tsunami in the South Adriatic Sea (Italy)  

Science.gov (United States)

Underwater landslides are hardly predictable and, especially if moving near the coast, represent a concrete threat for the population leaving in coastal areas and for infrastructures placed close to the shoreline. In the framework of the EU funded project TRANSFER, a set of possible sources all around the Mediterranean Sea have been mapped. Among the most common source areas there are the continental margins, owing to their steep slope, favouring the gravitational instability of deposited material. In this work we present the simulation of an ancient event, that occurred during the last glacial age (about 25 kyrs ago), in the Southern Adriatic Sea, known as the Gondola slide. It belongs to the SW Adriatic margin, a margin stretching by about 150 km that is characterized by canyons and widespread failure events that generated slide scars and extensive slide deposits. The most evident slide scar is around 10 km x 2.5 km, at the present-day sea depth of 180 m (but at the time of occurrence the depth was less than 50 meters), with a mobilized volume of around 4.5 km3 and a runout of more than 50 km. Recent bathymetric surveys (high resolution multi beam bathymetry) provided further details on the morphology of the deposit: the upper portion of the slide extends 23 km seaward, down to 800m sea depth, while the distal part is found over 50 km. In this work we consider the tsunami that very likely was generated by such a big slide. The simulation of the slide motion was performed through the code UBO-BLOCK1, developed by the University of Bologna Tsunami Research Team: The model is Lagrangian and block-based, computing the motion and the deformation of each of the blocks in which the total slide mass is discretised. The generation and propagation of the tsunami was simulated through the hydrodynamic code UBO-TSUFE, solving the Navier-Stokes equations in the shallow-water approximation over a mesh formed by triangular elements. The tsunami generation efficiency of Gondola Slide is measured through the Froude number and is found to be low. In spite of the small Froude number value, the tsunami was large because the estimated front of the Gondola Slide is very high with initial mass thickness in the order of several tens of meters. The zone most affected was the coastal region close to the source, that was hit by a long series of waves higher than 8-10 m with period between 15-20 min. The rise of sea level to its present position would lead to reduce the Froude number. Therefore, for a slide like Gondola Slide in identical conditions, but with the today's ocean depth, the associated tsunami would be quite smaller.

Tinti, S.; Zaniboni, F.; Armigliato, A.; Pagnoni, G.; Tonini, R.; Trincardi, F.; Foglini, F.

2009-04-01

 
 
 
 
61

The Tohoku Tsunami of 11 March 2011: The Key Event to Understanding Tsunami Sedimentation on the Coasts of Closed Bays of the Lesser Kuril Islands  

Science.gov (United States)

The Tohoku tsunami of 11 March 2011 manifested in the region of the South Kuril Islands, although, as a rule, the run-up heights in this region did not exceed 3 m. In closed bays that were covered with ice before the tsunami, the eroding capacity of tsunami waves was aggravated by the ice fragments they carried. Here, mud sheets formed, reaching up to 106 m inland. The 2012 studies have shown well-preserved tsunami deposits, evident 1.5 years after the event. A comparative analysis of tsunami deposits from the periphery and from the near-field area close to the tsunami source was performed; this was important for understanding the deposition mechanism during the event, as it had different strengths on different shores. The difference in run-up heights determined the considerable differences in erosion, sedimentation, distribution of tsunami deposits, the formation of sedimentary structures, grain-size composition, and diatom and foraminifera assemblages. The sources of the material also varied significantly from each other: the material came from offshore in closed bays located in the tsunami source periphery, while in the near-field region close to the epicenter, the most active erosion occurred in the inundation area. In the latter area, the main sources of sand were beaches and dunes, while soil erosion was the source of mud. Studies of the Tohoku tsunami on the coasts of the Lesser Kuril Islands demonstrated that mud layers in the sections of coastal lowlands in closed bays could contain preserved detailed geological records of paleotsunamis, even those with a small-height run-up. In the sections of coastal peatlands of closed bays on Shikotan Island, up to 7-9 layers of mud and silty sands were found, these can easily be traced for more than 500 m inland. The grain-size composition of the mud is similar to the deposits of the 2011 Tohoku tsunami. The marine origin of these deposits is confirmed by the diatom analysis data.

Razjigaeva, N. G.; Ganzey, L. A.; Grebennikova, T. A.; Ivanova, E. D.; Kharlamov, A. A.; Kaistrenko, V. M.; Arslanov, Kh. A.; Chernov, S. B.

2014-02-01

62

Tsunami Generated by the Late Bronze Age Eruption of Thera (Santorini), Greece  

Science.gov (United States)

Tsunami were generated during the Late Bronze Age (LBA) eruption of the island of Thera, in the southern Aegean Sea, by both caldera collapse, and by the entry of pyroclastic surges/flows and lahars/debris flows into the sea. Tsunami generated by caldera collapse propagated to the west producing deep-sea sedimentary deposits in the eastern Mediterranean Sea known as homogenites; open-ocean wave heights of about 1.9-17 m are estimated. Tsunami generated by the entry of pyroclastic flows/surges and lahars/debris flows into the sea propagated in all directions around the island; wave heights along coastal areas were about 7-12 m as estimated from newly identified tsunami deposits on eastern Thera as well as from pumice deposits found at archaeological sites on northern and eastern Crete.

McCoy, F. W.; Heiken, G.

63

THE POTENTIAL OF TSUNAMI GENERATION ALONG THE MAKRAN SUBDUCTION ZONE IN THE NORTHERN ARABIAN SEA. CASE STUDY: THE EARTHQUAKE AND TSUNAMI OF NOVEMBER 28, 1945  

Directory of Open Access Journals (Sweden)

Full Text Available Although large earthquakes along the Makran Subduction Zone are infrequent, the potential for the generation of destructive tsunamis in the Northern Arabian Sea cannot be overlooked. It is quite possible that historical tsunamis in this region have not been properly reported or documented. Such past tsunamis must have affected Southern Pakistan, India, Iran, Oman, the Maldives and other countries bordering the Indian Ocean.The best known of the historical tsunamis in the region is the one generated by the great earthquake of November 28, 1945 off Pakistan's Makran Coast (Balochistan in the Northern Arabian Sea. The destructive tsunami killed more than 4,000 people in Southern Pakistan but also caused great loss of life and devastation along the coasts of Western India, Iran, Oman and possibly elsewhere.The seismotectonics of the Makran subduction zone, historical earthquakes in the region, the recent earthquake of October 8, 2005 in Northern Pakistan, and the great tsunamigenic earthquakes of December 26, 2004 and March 28, 2005, are indicative of the active tectonic collision process that is taking place along the entire southern and southeastern boundary of the Eurasian plate as it collides with the Indian plate and adjacent microplates. Tectonic stress transference to other, stress loaded tectonic regions could trigger tsunamigenic earthquakes in the Northern Arabian Sea in the future.The northward movement and subduction of the Oman oceanic lithosphere beneath the Iranian micro-plate at a very shallow angle and at the high rate is responsible for active orogenesis and uplift that has created a belt of highly folded and densely faulted coastal mountain ridges along the coastal region of Makran, in both the Balochistan and Sindh provinces. The same tectonic collision process has created offshore thrust faults. As in the past, large destructive tsunamigenic earthquakes can occur along major faults in the east Makran region, near Karachi, as well as along the western end of the subduction zone. In fact, recent seismic activity indicates that a large earthquake is possible in the region west of the 1945 event. Such an earthquake can be expected to generate a destructive tsunami.Additionally, the on-going subduction of the two micro-plates has dragged tertiary marine sediments into an accretionary prism - thus forming the Makran coastal region, Thick sediments, that have accumulated along the deltaic coastlines from the erosion of the Himalayas, particularly along the eastern Sindh region near the Indus River delta, have the potential to fail and cause large underwater tsunamigenic slides. Even smaller magnitude earthquakes could trigger such underwater landslides. Finally, an earthquake similar to that of 1945 in the Makran zone of subduction, has the potential of generating a bookshelf type of failure within the compacted sediments – as that associated with the “silent” and slow 1992 Nicaragua earthquake – thus contributing to a more destructive tsunami. In conclusion, the Makran subduction zone has a relatively high potential for large tsunamigenic earthquakes.

George Pararas-Carayannis

2006-01-01

64

Physical Modeling of Tsunamis Generated By 3D Deformable Landslides in Various Scenarios From Fjords to Conical Islands  

Science.gov (United States)

Tsunamis generated by landslides and volcano flank collapse can be particularly devastative in the near field region due to locally high wave amplitudes and runup. The events of 1958 Lituya Bay, 1963 Vajont reservoir, 1980 Spirit Lake, 2002 Stromboli and 2010 Haiti demonstrate the danger of tsunamis generated by landslides or volcano flank collapses. Unfortunately critical field data from these events is lacking. Source and runup scenarios based on real world events are physically modeled using generalized Froude similarity in the three dimensional NEES tsunami wave basin at Oregon State University. A novel pneumatic landslide tsunami generator (LTG) was deployed to simulate landslides with varying geometry and kinematics. Two different materials are used to simulate landslides to study the granulometry effects: naturally rounded river gravel and cobble mixtures. The LTG consists of a sliding box filled with 1,350 kg of landslide material which is accelerated by means of four pneumatic pistons down a 2H:1V slope. The landslide is launched from the sliding box and continues to accelerate by gravitational forces up to velocities of 5 m/s. The landslide Froude number at impact with the water is in the range 1 tsunami data serve to validate and advance three-dimensional numerical landslide tsunami prediction models.

McFall, B. C.; Fritz, H. M.

2013-12-01

65

Tsunami Forecasting: The 10 August 2009 Andaman tsunami Demonstrates Progress  

Science.gov (United States)

The 10 August 2009 Andaman non-destructive tsunami in the Indian Ocean demonstrated advances in creating a tsunami-resilient global society. Following the Indian Ocean tsunami on 26 December 2004, scientists at the National Oceanic and Atmospheric Administration Center for Tsunami Research (NCTR) at the Pacific Marine Environmental Laboratory (PMEL) developed an interface for its validated and verified tsunami numerical model Method of Splitting Tsunamis (MOST). MOST has been benchmarked substantially through analytical solutions, experimental results and field measurements (Synolakis et al., 2008). MOST and its interface the Community Model Interface for Tsunami (ComMIT) are distributed through extensive capacity-building sessions for the Indian Ocean nations using UNESCO/Intergovernmental Oceanographic Commission (IOC), AusAID, and USAID funding. Over one hundred-sixty scientists have been trained in tsunami inundation mapping, leading to the first generation of inundation models for many Indian Ocean shorelines. During the 10 August 2009 Andaman tsunami event, NCTR scientists exercised the forecast system in research mode using the first generation inundation models developed during ComMIT trainings. Assimilating key data from a Kingdom of Thailand tsunameter, coastal tsunami amplitudes were predicted in Indonesia, Thailand, and India coastlines, before the first tsunami arrival, using models developed by ComMIT trainees. Since its first test in 2003, one more time, NCTR's forecasting methodology proved the effectiveness of operational tsunami forecasting using real-time deep-ocean data assimilated into forecast models (Wei et al., 2008 and Titov, 2009). The 2009 Andaman tsunami demonstrated that operational tsunami forecasting tools are now available and coupled with inundation mapping tools can be effective and can reduce false alarms. International collaboration is required to fully utilize this technology's potential. Enhanced educational efforts both at government and community levels are necessary to further reduce risk. References Synolakis, C.E., et al. (2008), Validation and verification of tsunami numerical models, Pure and Applied Geophysics. 165(11-12), 2197-2228. Titov, V.V. (2009), Chapter 12: Tsunami forecasting, The SEA, Tsunamis, vol. 15, Harvard University Press, p. 371-400. Wei, Y., et al. (2008), Real-time experimental forecast of the Peruvian tsunami of August 2007 for U.S. coastlines, Geophys. Res. Lett. 35, L04609.

Titov, Vasily; Moore, Christopher; Uslu, Burak; Kanoglu, Utku

2010-05-01

66

Development of a Tsunami Inundation Map in Detecting Tsunami Risk in Gulf of Fethiye, Turkey  

Science.gov (United States)

NAMIDANCE tsunami simulation and visualization tool is used to create tsunami inundation maps showing quantitative maximum tsunami flow depths in Fethiye. The risk of an extreme, but likely earthquake-generated tsunami is estimated at Fethiye Bay for 14 probabilistic earthquake scenarios. The bay is located 36°39'5?N 29°7'23?E, southwestern Turkey, which has coastline to the eastern Mediterranean Sea. The tsunami simulation and inundation assessment are performed in three stages: (1) formation of a digital elevation model of the region from the best available topography/bathymetry dataset, (2) estimation of a maximum credible tsunami scenario for the region and determination of related earthquake parameters, (3) high resolution tsunami simulation and computation of near shore and overland tsunami dynamics in the study area using tsunami simulation and visualization code NAMIDANCE, (4) determination of spatial distributions of tsunami characteristics (maximum water elevations, water velocities, flow depths) under the critical tsunami condition. The results are based on the most recent descriptions of potential tsunami sources, topographic and bathymetric databases, and tsunami numerical models. We present an innovative study concentrating on preparation of quantitative flow depths and inundation maps with a very high-resolution bathymetry/topographic dataset in the eastern Mediterranean. Inundation maps will be used to analyze the effects of possible tsunamis. The presented research is crucial to raising the awareness of government officials, the public, and other stake holders about the high probability of a tsunami event in Turkey. Moreover, the results of this study will help to plan for evacuation routes, establish safe zones, and assist in preparation for the tsunami, creating public awareness, and planning evacuation routes before the actual tsunami event happens.

Dilmen, Derya Itir; Kemec, Serkan; Yalciner, Ahmet Cevdet; Düzgün, Sebnem; Zaytsev, Andrey

2014-10-01

67

EVALUATION OF THE THREAT OF MEGA TSUNAMI GENERATION FROM POSTULATED MASSIVE SLOPE FAILURES OF ISLAND STRATOVOLCANOES ON LA PALMA, CANARY ISLANDS, AND ON THE ISLAND OF HAWAII  

Directory of Open Access Journals (Sweden)

Full Text Available Massive flank failures of island stratovolcanoes are extremely rare phenomena and none have occurred within recorded history. Recent numerical modeling studies, forecasting mega tsunami generation from postulated, massive slope failures of Cumbre Vieja in La Palma, Canary Islands, and Kilauea, in Hawaii, have been based on incorrect assumptions of volcanic island slope instability, source dimensions, speed of failure and tsunami coupling mechanisms. Incorrect input parameters and treatment of wave energy propagation and dispersion, have led to overestimates of tsunami far field effects. Inappropriate media attention and publicity to such probabilistic results have created unnecessary anxiety that mega tsunamis may be imminent and may devastate densely populated coastlines at locations distant from the source - in both the Atlantic and Pacific Oceans.The present study examines the assumptions and input parameters used by probabilistic numerical models and evaluates the threat of mega tsunami generation from flank failures of island stratovolcanoes. Based on geologic evidence and historic events, it concludes that massive flank collapses of Cumbre Vieja or Kilauea volcanoes are extremely unlikely to occur in the near geologic future. The flanks of these island stratovolcanoes will continue to slip aseismically, as in the past. Sudden slope failures can be expected to occur along faults paralleling rift zones, but these will occur in phases, over a period of time, and not necessarily as single, sudden, large-scale, massive collapses. Most of the failures will occur in the upper flanks of the volcanoes, above and below sea level, rather than at the basal decollement region on the ocean floor. The sudden flank failures of the volcanoes of Mauna Loa and Kilauea in 1868 and 1975 and the resulting earthquakes generated only destructive local tsunamis with insignificant far field effects. Caldera collapses and large slope failures associated with volcanic explosions of Krakatau in 1883 and of Santorin in 1490 B.C., generated catastrophic local tsunamis, but no waves of significance at distant locations. Mega tsunami generation, even from the larger slope failures of island stratovolcanoes, is extremely unlikely to occur. Greater source dimensions and longer wave periods are required to generate tsunamis that can have significant, far field effects. The threat of mega tsunami generation from massive flank failures of island stratovolcanoes has been greatly overstated.

George Pararas-Carayannis

2002-01-01

68

Assessment of tsunami hazard for the American Pacific coast from southern Mexico to northern Peru  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Central America has been struck by at least 49 tsunamis between 1539 and 1996. As many as 37 of these events occurred at the Pacific Coast, and 31 were generated by earthquakes. Some of the events have been destructive, but despite this, tsunamis are an underrated hazard in Central America: people are not aware that they are at risk and even recent tsunami events have been forgotten. Recent studies, following the destructive tsunami occurred in Nicaragua in 1992, have reveal...

Brizuela, B.; Armigliato, A.; Tinti, S.

2013-01-01

69

Numerical simulation of tsunami generation by cold volcanic mass flows at Augustine Volcano, Alaska  

Directory of Open Access Journals (Sweden)

Full Text Available Many of the world's active volcanoes are situated on or near coastlines. During eruptions, diverse geophysical mass flows, including pyroclastic flows, debris avalanches, and lahars, can deliver large volumes of unconsolidated debris to the ocean in a short period of time and thereby generate tsunamis. Deposits of both hot and cold volcanic mass flows produced by eruptions of Aleutian arc volcanoes are exposed at many locations along the coastlines of the Bering Sea, North Pacific Ocean, and Cook Inlet, indicating that the flows entered the sea and in some cases may have initiated tsunamis. We evaluate the process of tsunami generation by cold granular subaerial volcanic mass flows using examples from Augustine Volcano in southern Cook Inlet. Augustine Volcano is the most historically active volcano in the Cook Inlet region, and future eruptions, should they lead to debris-avalanche formation and tsunami generation, could be hazardous to some coastal areas. Geological investigations at Augustine Volcano suggest that as many as 12–14 debris avalanches have reached the sea in the last 2000 years, and a debris avalanche emplaced during an A.D. 1883 eruption may have initiated a tsunami that was observed about 80 km east of the volcano at the village of English Bay (Nanwalek on the coast of the southern Kenai Peninsula. Numerical simulation of mass-flow motion, tsunami generation, propagation, and inundation for Augustine Volcano indicate only modest wave generation by volcanic mass flows and localized wave effects. However, for east-directed mass flows entering Cook Inlet, tsunamis are capable of reaching the more populated coastlines of the southwestern Kenai Peninsula, where maximum water amplitudes of several meters are possible.

C. F. Waythomas

2006-01-01

70

Numerical simulation of tsunami generation by cold volcanic mass flows at Augustine Volcano, Alaska  

Science.gov (United States)

Many of the world's active volcanoes are situated on or near coastlines. During eruptions, diverse geophysical mass flows, including pyroclastic flows, debris avalanches, and lahars, can deliver large volumes of unconsolidated debris to the ocean in a short period of time and thereby generate tsunamis. Deposits of both hot and cold volcanic mass flows produced by eruptions of Aleutian arc volcanoes are exposed at many locations along the coastlines of the Bering Sea, North Pacific Ocean, and Cook Inlet, indicating that the flows entered the sea and in some cases may have initiated tsunamis. We evaluate the process of tsunami generation by cold granular subaerial volcanic mass flows using examples from Augustine Volcano in southern Cook Inlet. Augustine Volcano is the most historically active volcano in the Cook Inlet region, and future eruptions, should they lead to debris-avalanche formation and tsunami generation, could be hazardous to some coastal areas. Geological investigations at Augustine Volcano suggest that as many as 12-14 debris avalanches have reached the sea in the last 2000 years, and a debris avalanche emplaced during an A.D. 1883 eruption may have initiated a tsunami that was observed about 80 km east of the volcano at the village of English Bay (Nanwalek) on the coast of the southern Kenai Peninsula. Numerical simulation of mass-flow motion, tsunami generation, propagation, and inundation for Augustine Volcano indicate only modest wave generation by volcanic mass flows and localized wave effects. However, for east-directed mass flows entering Cook Inlet, tsunamis are capable of reaching the more populated coastlines of the southwestern Kenai Peninsula, where maximum water amplitudes of several meters are possible.

Waythomas, C. F.; Watts, P.; Walder, J. S.

2006-07-01

71

Analysis of the tsunami generated by the 2007 Noto Hanto earthquake  

Science.gov (United States)

The 2007 Noto Hanto earthquake generated a small tsunami that was recorded at several tide gauge stations along the coast of the Japan Sea. The most important feature of this tsunami is that two waveforms recorded at the Wajima and Noto tide gauge stations, which are located 30 km apart, showed very different later phases—the large later phases recorded at Noto were not observed at Wajima. Numerical simulation of the tsunami indicated that the difference was caused by the shallow water bathymetry around the Noto peninsula. The large tsunami that was amplified at a few tens of kilometers off the north coast of the Noto peninsula propagated towards the Noto tide gauge station, but not towards the Wajima station. This study indicates that the propagation of a tsunami caused by a shallow earthquake beneath a coastal area is significantly affected by the local bathymetry. A comparison of the observed and computed tsunami waveforms indicated that the slip amount of the fault was 0.8 m. The seismic moment of the Noto Hanto earthquake was calculated to be 0.94 × 1019 N m ( M w 6.6).

Tanioka, Yuichiro

2008-02-01

72

Pyroclastic Flow Generated Tsunami Waves Detected by CALIPSO Borehole Strainmeters at Soufriere Hills, Montserrat During Massive Dome Collapse: Numerical Simulations and Observations  

Science.gov (United States)

The July 12-13, 2003 eruption (dome collapse plus explosions) of Soufriere Hills Volcano in Montserrat, WI, is the largest historical lava dome collapse with ˜120 million cubic meters of the dome lost. Pyroclastic flows entered the sea at 18:00 AST 12 July at the Tar River Valley (TRV) and continued until the early hours of 13 July. Low-amplitude tsunamis were reported at Antigua and Guadaloupe soon after the dome collapse. At the time of eruption, four CALIPSO borehole-monitoring stations were in the process of being installed, and three very-broad-band Sacks-Evertson dilatometers were operational and recorded the event at 50 sps. The strongest strain signals were recorded at the Trants site, 5 km north of the TRV entry zone, suggesting tsunami waves >1 m high. Debris strandlines closer to TRV recorded runup heights as much as 8 m. We test the hypothesis that the strain signal is related to tsunami waves generated by successive pyroclastic flows induced during the dome collapse. Tsunami simulation models have been generated using GEOWAVE, which uses simple physics to recreate waves generated by idealized pyroclastic flows entering the sea at TRV. Each simulation run contains surface wave amplitude gauges located in key positions to the three borehole sites. These simulated wave amplitudes and periods are compared quantitatively with the data recorded by the dilatometers and with field observations of wave runup, to elucidate the dynamics of pyroclastic flow tsunami genesis and its propagation in shallow ocean water.

van Boskirk, E. J.; Voight, B.; Watts, P.; Widiwijayanti, C.; Mattioli, G. S.; Elsworth, D.; Hidayat, D.; Linde, A.; Malin, P.; Neuberg, J.; Sacks, S.; Shalev, E.; Sparks, R. J.; Young, S. R.

2004-12-01

73

Lituya Bay Landslide Impact Generated Mega-Tsunami 50th Anniversary  

Science.gov (United States)

On July 10, 1958, an earthquake Mw 8.3 along the Fairweather fault triggered a major subaerial landslide into Gilbert Inlet at the head of Lituya Bay on the southern coast of Alaska. The landslide impacted the water at high speed generating a giant tsunami and the highest wave runup in recorded history. The mega-tsunami runup to an elevation of 524 m caused total forest destruction and erosion down to bedrock on a spur ridge in direct prolongation of the slide axis. A cross section of Gilbert Inlet was rebuilt at 1:675 scale in a two-dimensional physical laboratory model based on the generalized Froude similarity. A pneumatic landslide tsunami generator was used to generate a high-speed granular slide with controlled impact characteristics. State-of-the-art laser measurement techniques such as particle image velocimetry (PIV) and laser distance sensors (LDS) were applied to the decisive initial phase with landslide impact and wave generation as well as the runup on the headland. PIV provided instantaneous velocity vector fields in a large area of interest and gave insight into kinematics of wave generation and runup. The entire process of a high-speed granular landslide impact may be subdivided into two main stages: (a) Landslide impact and penetration with flow separation, cavity formation and wave generation, and (b) air cavity collapse with landslide run-out and debris detrainment causing massive phase mixing. Formation of a large air cavity — similar to an asteroid impact — in the back of the landslide is highlighted. A three-dimenional pneumatic landslide tsunami generator was designed, constructed and successfully deployed in the tsunami wave basin at OSU. The Lituya Bay landslide was reproduced in a three-dimensional physical model at 1:400 scale. The landslide surface velocities distribution was measured with PIV. The measured tsunami amplitude and runup heights serve as benchmark for analytical and numerical models.

Fritz, Hermann M.; Mohammed, Fahad; Yoo, Jeseon

2009-02-01

74

Evidence of tsunami events in the Paleolimnological record of Lake Pátzcuaro, Michoacán, Mexico  

Scientific Electronic Library Online (English)

Full Text Available SciELO Mexico | Language: English Abstract in spanish El actual lago de Pátzcuaro tiene una elevación de 2035 m sobre el nivel del mar. Históricamente, ha alcanzado una elevación de 2041 m, lo cual aislaba una porción de la isla cerca de la población de Jarácuaro en la parte sureste del lago. Dos trincheras realizadas en la antigua isla revelan secuenc [...] ias estratigráficas tripartitas similares. En una trinchera de 3.1 m de profundidad, la secuencia de la base a la cima está formada por la Unidad A que comprende arcillas y limos ricos en diatomeas plegados y fallados con capas de arena volcánica. Estos depósitos están fechados entre 24 y 10 mil años BP. Unidad B que comprende una mezcla caótica de arenas volcánicas y lapilli, con abundantes restos de peces, bivalvos, gasterópodos y ostrácodos, de 10 cm de espesor con un contacto erosivo sobre la Unidad A. Los ostrácodos incluyen valvas articuladas con una mezcla de especies pelágicas de agua profunda y especies litorales. Los fragmentos de artefactos cerámicos pertenecientes al Período Post-Clásico (900 a 1520 AD) son abundantes. La Unidad C comprende una unidad de 20 cm de espesor de limo arcilloso rico en materia orgánica con restos de gasterópodos, semillas, líticos angulares y fragmentos de piezas cerámicas del Post-Clásico. La Unidad B sugiere una resedimentación catastrófica de los depósitos del piso del lago atribuidos a un tsunami. La Unidad C es consistente con condiciones sublacustres que están históricamente documentadas de 1858 a 1947. Un tsunami en el Lago de Pátzcuaro en 1858 ha sido registrado históricamente. El tsunami pudo haber sido creado por movimientos de falla o colapso del flanco suroeste de la isla de Janitzio. La ola del tsunami pudo haber contribuido al rápido aumento del lago de Pátzcuaro después del evento sísmico de 1858. Abstract in english Modern Lake Pátzcuaro has a surface elevation of 2035 m a.s.l. Historically, it reached an elevation of 2041 m a.s.l., which isolated a portion of the island near the town of Jarácuaro in the southeastern part of the lake. Two trenches in the former island reveal similar tripartite stratigraphic seq [...] uences. In a 3.1 m deep trench, the sequence from bottom to top comprises Unit A constituted by folded and faulted diatom-rich clay and silt with beds of volcanic sand. These deposits are dated between 24 and 10 ky BP; Unit B constituted by a 10 of cm chaotic mixture of volcanic sand and lapilli with abundant remains of fish, bivalves, gastropods and ostracodes that is rests on above an erosional unconformity. The ostracodes include articulated valves with a mixture of deep-water pelagic species and attached littoral species. Highly fractured diatom shows a mixture of planktonic and benthic habitats. Fragments of ceramic artifacts dated to the Post-Classic Period (900 to 1520 AD) are abundant; Unit Cconstituted by a 20 cm thick unit of organic-rich argillaceous silt with remains of gastropods, seeds, angular lithoclasts and fragments of Post-Classic ceramic artifacts. Unit B suggests a catastrophic resedi mentation of lake floor deposits attributed to a tsunami. Unit C is consistent with sublacustrine conditions that are historically documented from 1858 to 1947. A tsunami in Lake Pátzcuaro in 1858 has been historically recorded. The tsunami was created either by fault movement or collapse of the SW flank of the island of Janitzio. The tsunami wave may have contributed to the rapid rise of Lake Pátzcuaro following the 1858 seismic event.

Victor Hugo, Garduño-Monroy; Diana Cinthia, Soria-Caballero; Isabel, Israde-Alcántara; Víctor Manuel, Hernández Madrigal; Alejandro, Rodríguez-Ramírez; Mikhail, Ostroumov; Miguel Ángel, Rodríguez-Pascua; Arturo, Chacon-Torres; Juan Carlos, Mora-Chaparro.

75

Numerical simulations of tsunami generated by underwater volcanic explosions at Karymskoye lake (Kamchatka, Russia) and Kolumbo volcano (Aegean Sea, Greece)  

Science.gov (United States)

Increasing human activities along the coasts of the world arise the necessity to assess tsunami hazard from different sources (earthquakes, landslides, volcanic activity). In this paper, we simulate tsunamis generated by underwater volcanic explosions from (1) a submerged vent in a shallow water lake (Karymskoye Lake, Kamchatka), and (2) from Kolumbo submarine volcano (7 km NE of Santorini, Aegean Sea, Greece). The 1996 tsunami in Karymskoye lake is a well-documented example and thus serves as a case-study for validating the calculations. The numerical model reproduces realistically the tsunami runups measured onshore. Systematic numerical study of tsunamis generated by explosions of Kolumbo volcano is then conducted for a wide range of energies. Results show that in case of reawakening, Kolumbo volcano might represent a significant tsunami hazard for the northern, eastern and southern coasts of Santorini, even for small-power explosions.

Ulvrová, M.; Paris, R.; Kelfoun, K.; Nomikou, P.

2013-11-01

76

Numerical simulations of tsunamis generated by underwater volcanic explosions at Karymskoye lake (Kamchatka, Russia) and Kolumbo volcano (Aegean Sea, Greece)  

Science.gov (United States)

Increasing human activities along the coasts of the world provoke the necessity to assess tsunami hazard from different sources (earthquakes, landslides, volcanic activity). In this paper, we simulate tsunamis generated by underwater volcanic explosions from (1) a submerged vent in a shallow water lake (Karymskoye Lake, Kamchatka), and (2) from Kolumbo submarine volcano (7 km NE of Santorini, Aegean Sea, Greece). The 1996 tsunami in Karymskoye lake is a well-documented example and thus serves as a case study for validating the calculations. The numerical model reproduces realistically the tsunami run-ups measured onshore. Systematic numerical study of tsunamis generated by explosions of the Kolumbo volcano is then conducted for a wide range of energies. Results show that in case of reawakening, the Kolumbo volcano might represent a significant tsunami hazard for the northern, eastern and southern coasts of Santorini, even for small-power explosions.

Ulvrová, M.; Paris, R.; Kelfoun, K.; Nomikou, P.

2014-02-01

77

The Tsunami Geology of the Bay of Bengal Shores and the Predecessors of the 2004 Indian Ocean Event  

Science.gov (United States)

The 2004 Aceh-Andaman earthquake exceeded the known Indian Ocean precedents by its 1,300-km long fault rupture and the height and reach of its tsunami. Literature of the ancient Chola dynasty (AD 9-11 centuries) of south India and the archeological excavations allude to a sea flood that crippled the historic port at Kaveripattinam, a trading hub for Southeast Asia. Here, we combine a variety of data from the rupture zone as well as the distant shores to build a tsunami history of the Bay of Bengal. A compelling set of geological proxies of possible tsunami inundation include boulder beds of Car Nicobar Island in the south and the East Island in the northernmost Andaman, a subsided fossil mangrove forest near Port Blair and a washover sedimentation identified in the Kaveripattinam coast of Tamil Nadu, south India. We have developed an extensive chronology for these geological proxies, and we analyze them in conjunction with the historical information culled from different sources for major sea surges along the Bay of Bengal shores. The age data and the depositional characteristics of these geological proxies suggest four major tsunamis in the last 2000 years in the Bay of Bengal, including the 1881 Car Nicobar tsunami. Among these, the evidence for the event of 800-1200 cal yr BP is fairly well represented on both sides of the Bay of Bengal shores. Thus, we surmise that the 800-1000-year old tsunami mimics the transoceanic reach of the 2004 Indian Ocean and the age constraints also agree with the sea surge during the Chola period. We also obtained clues for a possible medieval tsunami from the islands occurred probably a few hundred years after the Chola tsunami, but its size cannot constrained, nor its source. The convergence of ages and the multiplicity of sites would suggest at least one full size predecessor of the 2004 event 1000-800 years ago.

Rajendran, C.; Rajendran, K.; Seshachalam, S.; Andrade, V.

2010-12-01

78

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

Science.gov (United States)

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

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

2013-04-01

79

GR@PPA Event Generator  

CERN Document Server

The history and the present status of the GR@PPA event generator are briefly reviewed. The development of GR@PPA started in 2000 in order to provide a framework of NLO event generators for hadron collision interactions. After the first release of the package (GR@PPA\\_4b) in 2002, which supported four bottom quark production processes, many multi-particle production processes have been added to the package: GR@PPA\\_ALL in 2004 and GR@PPA 2.7 in 2006. Now we are going to release a new package (GR@PPA 2.8), which supports single and double weak-boson production processes with an initial-state jet matching. Though the matrix elements presently included are still at the tree level, this new release is an important step towards constructing consistent NLO event generators.

Odaka, Shigeru

2010-01-01

80

Landslide-generated tsunamis runup at the coast of a conical island: New physical model experiments  

Science.gov (United States)

This paper presents new physical model experiments on tsunamis generated by landslides at the coast of a conical island. The experiments have been carried out in a large wave tank; the radius of the island coastline and the falling height of the landslide have been varied during the experimental campaign. The landslide is reproduced by a solid body shaped as a half of an ellipsoid. Tsunami runup is measured using special wave gauges; a detailed analysis of the runup along the coastline is presented, with special attention to the role of each wave in the packet and to the evolution of the envelope of the first group of waves.

di Risio, M.; de Girolamo, P.; Bellotti, G.; Panizzo, A.; Aristodemo, F.; Molfetta, M. G.; Petrillo, A. F.

2009-01-01

 
 
 
 
81

Waves of Destruction: Tsunamis  

Science.gov (United States)

Web companion to an episode of the PBS/WNET television series "Savage Earth" devoted to tsunamis. The homepage article provides a brief overview of the mechanism that creates tsunamis, the enormous energy they release, and the role of plate tectonics in earthquake and tsunami generation. Sidebar pages discuss tsunami monitoring and advance warning, and geologic investigations that reveal evidence of destructive tsunamis in the past. There is also an animation that shows how an earthquake at a subduction zone can cause the sea floor to snap upward abruptly, displacing water and generating a tsunami, and a video interview with a survivor of the 1946 tsunami that struck the Hawaiian Islands.

82

Potential predecessors of the 2004 Indian Ocean Tsunami — Sedimentary evidence of extreme wave events at Ban Bang Sak, SW Thailand  

Science.gov (United States)

Where historical records are short and/or fragmentary, geological evidence is an important tool to reconstruct the recurrence rate of extreme wave events (tsunamis and/or storms). This is particularly true for those coastal zones around the Indian Ocean, where predecessors of similar magnitude as the 2004 Indian Ocean Tsunami (IOT) have not been reported by written sources. In this context, the sedimentary record of the Holocene coastal plain of Ban Bang Sak (Phang-nga province, Thailand) provides evidence of multiple prehistoric coastal flooding events in the form of allochthonous sand beds, which were radiocarbon dated to 700-500, 1350-1180, and younger than 2000 cal BP. The layers were assigned to high-energy events of marine origin, which could be either tsunamis or tropical storms, by means of granulometry, geochemistry, vertical structure, and macrofossil content. Although no landfall of a strong storm has occurred in the last 150 years of meteorological data recording, cyclones cannot be ruled out for the last centuries and millennia. However, discrimination between tsunami and storm origin was mainly based on the comparison of the palaeoevent beds with the local deposit of the IOT, which revealed similar characteristics in regard to spatial extend and sediment properties. Furthermore, the youngest palaeoevent correlates with contemporaneous deposits from Thailand and more distant coasts. Hence, we relate it to a basin wide tsunami which took place 700-500 years ago. For the sediments of older extreme events, deposited between 2000 and 1180 cal BP, we found no unambiguous counterparts at other sites; nevertheless, at least for now, they are treated as tsunami candidates.

Brill, D.; Brückner, H.; Jankaew, K.; Kelletat, D.; Scheffers, A.; Scheffers, S.

2011-08-01

83

A Probabilistic Tsunami Hazard Assessment for Indonesia  

Science.gov (United States)

We present the first national probabilistic tsunami hazard assessment (PTHA) for Indonesia. This assessment considers tsunami generated from near-field earthquakes sources around Indonesia as well as regional and far-field sources, to define the tsunami hazard at the coastline. The PTHA methodology is based on the established stochastic event-based approach to probabilistic seismic hazard assessment (PSHA) and has been adapted for tsunami. The earthquake source information is primarily based on the recent Indonesian National Seismic Hazard Map and included a consensus-workshop with Indonesia's leading tsunami and earthquake scientists to finalize the seismic source models and logic trees to include epistemic uncertainty. Results are presented in the form of tsunami hazard maps showing the expected tsunami height at the coast for a given return period, and also as tsunami probability maps, showing the probability of exceeding a tsunami height of 0.5m and 3.0m at the coast. These heights define the thresholds for different tsunami warning levels in the Indonesian Tsunami Early Warning System (Ina-TEWS). The results show that for short return periods (100 years) the highest tsunami hazard is the west coast of Sumatra, the islands of Nias and Mentawai. For longer return periods (>500 years), the tsunami hazard in Eastern Indonesia (north Papua, north Sulawesi) is nearly as high as that along the Sunda Arc. A sensitivity analysis of input parameters is conducted by sampling branches of the logic tree using a monte-carlo approach to constrain the relative importance of each input parameter. The results from this assessment can be used to underpin evidence-based decision making by disaster managers to prioritize tsunami mitigation, such as developing detailed inundation simulations for evacuation planning.

Horspool, N.; Pranantyo, I.; Griffin, J.; Latief, H.; Natawidjaja, D.; Kongko, W.; Cipta, A.; Koetapangwa, B.; Anugrah, S.; Thio, H. K.

2012-12-01

84

Tsunami Modeling and Inundation Mapping in Southcentral Alaska  

Science.gov (United States)

The Alaska Earthquake Information Center (AEIC) participates in the National Tsunami Hazard Mitigation Program by evaluating and mapping potential tsunami inundation of coastal Alaska. We evaluate potential tsunami hazards for several coastal communities near the epicenter of the 1964 Great Alaska Earthquake and numerically model the extent of their inundation due to tsunamis generated by earthquake and landslide sources. Tsunami scenarios include a repeat of the tsunami triggered by the 1964 Great Alaska Earthquake, as well as hypothetical tsunamis generated by an extended 1964 rupture, a Cascadia megathrust earthquake, earthquakes from the Prince William Sound and Kodiak asperities of the 1964 rupture, and a hypothetical Tohoku-type rupture in the Gulf of Alaska region. Local underwater landslide events in several communities are also considered as credible tsunamigenic scenarios. We perform simulations for each of the source scenarios using AEIC's recently developed and tested numerical model of tsunami wave propagation and runup. Results of the numerical modeling are verified by simulating the tectonic and landslide-generated tsunamis observed during the 1964 earthquake. The tsunami scenarios are intended to provide guidance to local emergency management agencies in tsunami hazard assessment, evacuation planning, and public education for reducing future casualties and damage from tsunamis. During the 1964 earthquake, locally generated waves of unknown origin were identified at several communities, located in the western part of Prince William Sound. The waves appeared shortly after the shaking began and swept away most of the buildings while the shaking continued. We model the tectonic tsunami assuming different tsunami generation processes and claim the importance of including both vertical and horizontal displacement into the 1964 tsunami generation process.

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

2013-12-01

85

A review on earthquake and tsunami hazards of the Sumatran plate boundary: Observing expected and unexpected events after the Aceh-Andaman Mw 9.15 event  

Science.gov (United States)

The 600-km Mentawai megathrust had produced two giant historical earthquakes generating big tsunamies in 1797 and 1833. The SuGAr (Sumatran GPS continuous Array) network, first deployed in 2002, shows that the subduction interface underlying Mentawai Islands and the neighboring Nias section in the north are fully locked, thus confirming their potential hazards. Outreach activities to warn people about earthquake and tsunamies had been started since 4 months prior to the 26 December 2004 in Aceh-Andaman earthquake (Mw 9.15). Later in March 2005, the expected megathrust earthquake (Mw 8.7) hit Nias-Simelue area and killed about 2000 people, releasing the accumulated strain since the previous 1861 event (~Mw 8.5). After then many Mw 7s and smaller events occured in Sumatra, filling areas between and around two giant ruptures and heighten seismicities in neighboring areas. In March 2007, the twin earthquake disaster (Mw 6.3 and Mw 6.4) broke two consecutive segments of the transcurrent Sumatran fault in the Singkarak lake area. Only six month later, in September 2007, the rapid-fire-failures of three consecutive megathrust patches (Mw 8.5, Mw 7.9 and Mw 7.0) ruptured a 250-km-section of the southern part of the Mentawai. It was a big surprise since this particular section is predicted as a very-low coupled section from modelling the SuGAr data, and hence, bypassing the more potential fully coupled section of the Mentawai in between the 2005 and 2007 ruptures. In September 2009, a rare unexpected event (Mw 7.6) suddenly ruptured an intracrustal fault in the subducted slab down under Padang City and killed about 500 people. Padang had been in preparation for the next tsunami but not for strong shakes from near by major earthquake. This event seems to have remotely triggered another Mw 6.7 on the Sumatran fault near kerinci Lake, a few hundred kilometers south of Padang, in less than a day. Just a year later, in November 2010, again an unexpected large slow-slip event of Mw 7.8 ruptured an up-dip section of the 2007 rupture, west of the South Pagai of Mentawai Islands. It shook the region only gently but woke deadly tsunami up to 14 meter heights and killed about 500 people. Despite it has been a bit quite in the past three years but the amount of strain left on the Mentawai segment, especially under Siberut, Sipora and North Pagai Islands is about Mw 8.8 still, waiting to be released sometime in the near future. Beside Mentawai, stydies on prehistorical earthquakes and mapping off strain budget and releases along the Aceh-Andaman indicates that a Mw 8 or greater earthquake is still possible to occur in the next decades. Moreover, the status and characteristics of the megathrust section south of the Mentawai, the Sunda Strait to south Java Ocean, is largely unknown so far. Nonetheless, we do know that this southernmost section has been quite for the past several hundreds years, suggesting a possible seismic gap, and it is close to dense population of industrial and urban areas. Learning from experience, we should not just prepare for the expected of well known sources but also the unexpected ones.

Natawidjaja, D.

2013-12-01

86

LARGE EARTHQUAKES AND TSUNAMIS AT THE SAMOA CORNER IN THE CONTEXT OF THE 2009 SAMOA EVENT  

Science.gov (United States)

We examine the seismic properties of the 2009 Samoa earthquake in the context of its tsunami, the first one in 45 years to cause significant damage on U.S. soil. The event has a normal faulting geometry near the bend ending the 3000-km long Tonga-Kermadec subduction zone. Other large normal faulting tsunamigenic earthquakes include the 1933 Sanriku, 1977 Sumba and 2007 Kuril events. The 2009 Samoa earthquake shares with such intraplate earthquakes a slightly above average E/M0 (THETA = -4.82), but has a more complex geometry, a relatively long duration, and large CLVD (11%). Same-day seismicity appears detached to the SW of the fault plane, and 7 out of the 8 CMT regional solutions following the main shock are rotated at least 69 deg. away from its own mechanism. This points out to a mechanism of stress transfer rather than genuine aftershocks, in a pattern reminiscent of the 1933 Sanriku earthquake. Most of the seismic moment release around the Samoa corner involves normal faulting. To the South (16.5-18 deg. S; 1975, 1978, 1987, 2006), solutions consistently feature a typical intraplate lithospheric break. To the NW (15.5 deg. S), the 1981 event features a tear in the plate along Govers and Wortel's [2005] STEP model. The 2009 event is more complex, apparently involving rupture along a quasi-NS plane. An event presumably similar to 2009 took place on 26 June 1917, for which there is a report of a 12-m tsunami at Pago Pago. That event relocates 200 km to the NW, but its error ellipse includes the 2009 epicenter. The 1917 moment, tentatively 1.3 10**28 dyn*cm, is comparable to 2009. As suggested by Solov'ev and Go [1984], the report of a 12-m wave in Samoa during the 01 May 1917 Kermadec earthquake is most probably erroneous. We will present studies of the other large earthquakes of the past century in the area, notably the confirmed tsunamigenic events of 01 Sep. 1981 (damage on Savaii), 26 Dec 1975 (24 cm at PPG), 02 Apr 1977 (12 cm at PPG), 06 Oct 1987 and 07 Apr 1995 (only centimetric at PPG).

Okal, E.; Kirby, S. H.

2009-12-01

87

Numerical modelling of potential submarine landslides and generated tsunami in Sumatra  

Science.gov (United States)

Recent studies suggests that tsunami risk along the SW coast of Sumatra could be due to co-seismic slip along a backthrust at the NE Margin of the Mentawai Island and associated landslides (Singh et al., 2010). Using a combination of high-resolution seismic reflection and bathymetry data, they observed deposits of large submarine landslides at the NE margin of Mentawai Island and suggest that the high wave that occurred in 1797 might have been enhanced by landslides, producing a large localised tsunami. Until now most of the work devoted to tsunami hazard assessment in the area of Sumatra Island focussed on megaearthquakes earthquakes generated tsunamis. Therefore, estimating the run up heights due to submarine landslides is essential for risk mitigation along the SW coast of Sumatra. A series of numerical scenarios are performed here to simulate potential submarine landslides and generated tsunamis in the area of Sumatra Island. The height and velocity of the water wave and the impact zones are calculated using a new numerical model solving the depth-averaged shallow water equations with high order finite volume methods. This model corresponds to the 2D extension of the model developed by Fernández-Nieto et al., 2008. The fluidized mass is modeled using a generalization of the Savage-Hutter model [Savage and Hutter, 1989] by including the role of buoyancy and fluid into the thin-layer equations with a Coulomb-type friction law. Our model takes into account the coupling between the fluid and the landslides and incorporates the rigorous description of topography effects that play a key role in the dynamics of landslides. We study the magnitude of variation of the wave expected depending on the location and volume released. These results shows that landslide generated tsunamis have to be taken into account for risk assessment in the area of Sumatra Island. E.D. Fernández-Nieto, F. Bouchut, D. Bresch, M.J. Castro, A. Mangeney, 2008. A new Savage-Hutter type model for submarine avalanches and generated tsunami, J. Comput. Physics 7720-7754, 227. S.B. Savage, K. Hutter. The dynamics of avalanches of granular materials frominitiation to run-out. Acta Mech. 86, 201-223 (1989) Singh, Satish C., Nugroho D. Hananto, Ajay P. S. Chauhan, H. Permana, Marine Denolle, Andri Hendriyana, Danny Natawidjaja, 2010. Evidence of active backthrusting at the NE Margin of Mentawai Islands, SW Sumatra, Geophys. J. Int., 180(2), 703-714, February 2010

Fernandez-Nieto, E.; Mangeney, A.; Singh, S. C.; Chauhan, A.; Bouchut, F.; Castro Díaz, M.

2010-12-01

88

Tsunami risk assessment in the Marquesas Islands (French Polynesia through numerical modeling of generic far-field events  

Directory of Open Access Journals (Sweden)

Full Text Available Earthquakes occurring at the Pacific Rim can trigger tsunamis that propagate across the ocean and can produce significant damages far away from the source. In French Polynesia, the Marquesas Islands are the most exposed to the far-field tsunami hazards, since they are not protected by any outer coral reef and since submarine slopes are less steep than in other islands. Between 1994 and 1996, four tsunamis have reached the bays of the archipelago, among them, the tsunami initiated by the Chilean Mw 8.1 earthquake, produced up to 3 m high waves in Tahauku Bay. Numerical modeling of these recent events has already allowed us to validate our method of resolution of hydrodynamics laws through a finite-difference scheme that simulates the propagation of the tsunamis across the ocean and computes the inundation heights (run-up in remote bays. We present in this paper the simulations carried out to study potentially threatening areas located at the Pacific Rim, on the seismogenic Aleutian and Tonga subduction zones. We use a constant seismic moment source (that of the Mw 8.1 Chile 1995 earthquake, M0 = 1.2 1021 N.m located at several potential epicenters, with the fault strike adapted from the regional seismotectonics pattern. Our results show that the sources chosen in the Aleutian trench do not produce large inundations in the Marquesas bays, except for the easternmost source (longitude 194° E. Sources located in the Tonga trench do not produce high amplifications either, except for the northernmost one (latitude 16° S. We also discuss the behaviour of the tsunami waves within the archipelago, and evidence contrasting responses depending on the arrival azimuths. These results show that, for a given initial seismic energy, the tsunami amplification in remote bays is highly dependent on the source location and fault strike.

H. Hébert

2001-01-01

89

Parton Distributions for Event Generators  

Digital Repository Infrastructure Vision for European Research (DRIVER)

In this paper, conventional Global QCD analysis is generalized to produce parton distributions optimized for use with event generators at the LHC. This optimization is accomplished by combining the constraints due to existing hard-scattering experimental data with those from anticipated cross sections for key representative SM processes at LHC (by the best available theory) as joint input to the global analyses. The PDFs obtained in these new type of global analyses using ma...

Lai, Hung-liang; Huston, Joey; Mrenna, Stephen; Nadolsky, Pavel; Stump, Daniel; Tung, Wu-ki; Yuan, C. -p

2009-01-01

90

TSUNAMI INFORMATION SOURCES - PART 4  

Directory of Open Access Journals (Sweden)

Full Text Available I have expanded substantially my list of information sources on: tsunami generation (sources, impulsive mechanisms, propagation, effects of nearshore bathymetry, and wave run-up on shore - including physical (hydraulic modeling and numerical modeling. This expanded list includes the subjects of field investigations of tsunamis soon after an event; damage effects in harbors on boats, ships, and facilities; tsunami wave-induced forces; damage by tsunami waves to structures on shore; scour/erosion; hazard mitigation; land use planning; zoning; siting, design, construction and maintenance of structures and infrastructure; public awareness and education; distant and local sources; tsunami warning and evacuation programs; tsunami probability and risk criteria. A few references are on "sedimentary signatures" useful in the study of historic and prehistoric tsunamis (paleo-tsunamis. In addition to references specifically on tsunamis, there are references on long water wave and solitary wave theory; wave refraction, diffraction, and reflection; shelf and basin free and forced oscillations (bay and harbor response; seiches; edge waves; Mach- reflection of long water waves ("stem waves"; wave run-up on shore; energy dissipation. All are important in understanding tsunamis, and in hazard mitigation. References are given on subaerial and submarine landslide (and rockfall generated waves in reservoirs, fjords, bays, and ocean; volcano explosive eruptions/collapse; underwater and surface explosions; asteroid impact. This report is in two parts: 1 Bibliographies, books and pamphlets, catalogs, collections, journals and newsletters, maps, organizations, proceedings, videos and photos; 2 Articles, papers, reports listed alphabetically by author.Many papers on the Indian Ocean (Sumatra tsunami of 26 December 2004, were given at the 22nd IUGG International Tsunami Symposium, Chania, Crete, 27-29 June 2005, but had not been published at the date of this report. For the program, see http://www.gein.noa.gr/English/tsunamis.htmThis list of tsunami information sources (115 pp, about 3,300 entries is also available on a diskette, at the Water Resources Center Archives, 410 O'Brien Hall, University of California, Berkeley, CA, 94720-1718. Most of the publications are available in the Water Resources Center Archives or the Earth Sciences Library, University of California, Berkeley, CA.I wish to acknowledge my appreciation of the great help of the staff of the Water Resources Center Archives in finding some difficult to obtain publications; in particular Paul S. Atwood for his help for those on websites and other computer sources. I want to thank John M. Wiegel for his continuous help in searching for sources on websites via computer search-engines.

Robert L. Wiegel

2006-01-01

91

Investigation of tsunami generated by the Mariana trench earthquake of April 6, 1990. 1990 nen 4 gatsu 6 ka Mariana kaiko jishin ni yoru tsunami  

Energy Technology Data Exchange (ETDEWEB)

There was an earthquake on April 6, 1990 whose epicenter was in the vicinity of the Mariana Trench, 170km to the east of Saipan island. The earthquake accompanied a tsunami which was observed in a wide area in Japan, and the tsunami were put on records at many tidal stations. The tidal records made by various stations were analyzed to study the scale and characteristics of the tsunami. Continuous 3 hour wave surface was observed along the island arc from the Kanto districts to the Ryukyu Islands with little difference in the propagation times. The wave was comparatively higher in the Shikoku districts with the height of 40cm, and the amplitude was larger at the point where initial wave period of 8 minutes was observed. The magnitude of the tsunami was estimated to be m=2, which is one grade higher than average for the scale of the earthquake. The reason can be considered as the concentration of energy in Japan by the effect of submarine topography and by the effect of a high-angle thrust fault. The Tsunami generated along Ogasahara and Mariana Trench has a larger scale than that of the average earthquake, and can be explained by the high-angle thrust of the plate near the trench. 8 refs., 7 figs., 1 tab.

Hatori, T. (Saitama (Japan))

1991-06-24

92

Statistical Analysis of Tsunami Variability  

Science.gov (United States)

The purpose of this paper was to investigate statistical variability of seismically generated tsunami impact. The specific goal of the work was to evaluate the variability in tsunami wave run-up due to uncertainty in fault rupture parameters (source effects) and to the effects of local bathymetry at an individual location (site effects). This knowledge is critical to development of methodologies for probabilistic tsunami hazard assessment. Two types of variability were considered: • Inter-event; • Intra-event. Generally, inter-event variability refers to the differences of tsunami run-up at a given location for a number of different earthquake events. The focus of the current study was to evaluate the variability of tsunami run-up at a given point for a given magnitude earthquake. In this case, the variability is expected to arise from lack of knowledge regarding the specific details of the fault rupture "source" parameters. As sufficient field observations are not available to resolve this question, numerical modelling was used to generate run-up data. A scenario magnitude 8 earthquake in the Hellenic Arc was modelled. This is similar to the event thought to have caused the infamous 1303 tsunami. The tsunami wave run-up was computed at 4020 locations along the Egyptian coast between longitudes 28.7° E and 33.8° E. Specific source parameters (e.g. fault rupture length and displacement) were varied, and the effects on wave height were determined. A Monte Carlo approach considering the statistical distribution of the underlying parameters was used to evaluate the variability in wave height at locations along the coast. The results were evaluated in terms of the coefficient of variation of the simulated wave run-up (standard deviation divided by mean value) for each location. The coefficient of variation along the coast was between 0.14 and 3.11, with an average value of 0.67. The variation was higher in areas of irregular coast. This level of variability is similar to that seen in ground motion attenuation correlations used for seismic hazard assessment. The second issue was intra-event variability. This refers to the differences in tsunami wave run-up along a section of coast during a single event. Intra-event variability investigated directly considering field observations. The tsunami events used in the statistical evaluation were selected on the basis of the completeness and reliability of the available data. Tsunami considered for the analysis included the recent and well surveyed tsunami of Boxing Day 2004 (Great Indian Ocean Tsunami), Java 2006, Okushiri 1993, Kocaeli 1999, Messina 1908 and a case study of several historic events in Hawaii. Basic statistical analysis was performed on the field observations from these tsunamis. For events with very wide survey regions, the run-up heights have been grouped in order to maintain a homogeneous distance from the source. Where more than one survey was available for a given event, the original datasets were maintained separately to avoid combination of non-homogeneous data. The observed run-up measurements were used to evaluate the minimum, maximum, average, standard deviation and coefficient of variation for each data set. The minimum coefficient of variation was 0.12 measured for the 2004 Boxing Day tsunami at Nias Island (7 data) while the maximum is 0.98 for the Okushiri 1993 event (93 data). The average coefficient of variation is of the order of 0.45.

Zolezzi, Francesca; Del Giudice, Tania; Traverso, Chiara; Valfrè, Giulio; Poggi, Pamela; Parker, Eric J.

2010-05-01

93

Modeling propagation and inundation of the 11 March 2011 Tohoku tsunami  

Digital Repository Infrastructure Vision for European Research (DRIVER)

On 11 March 2011 the Tohoku tsunami devastated the east coast of Japan, claiming thousands of casualties and destroying coastal settlements and infrastructure. In this paper tsunami generation, propagation, and inundation are modeled to hindcast the event. Earthquake source models with heterogeneous slips are developed in order to match tsunami observations, including a best fit initial sea surface elevation with water levels up to 8 m. Tsunami simulations were compared to b...

Løvholt, F.; Kaiser, G.; Glimsdal, S.; Scheele, L.; Harbitz, C. B.; Pedersen, G.

2012-01-01

94

Tsunami Inundation Mapping of Coastal Alaska  

Science.gov (United States)

Seismic events that occur within the Alaska-Aleutian subduction zone have a high potential for generating both local and Pacific-wide tsunamis. To help mitigate the large risk these earthquakes and tsunamis pose to Alaskan coastal communities, the Alaska Tsunami Modeling Team addresses the problem of predicting runup of tsunami waves using a numerical modeling technique. The model solves nonlinear shallow-water equations with a finite-difference method. Embedded grids of different resolution are employed to increase spatial resolution in the shelf area. Numerical simulations yield runup heights, extent of maximum inundation for chosen tsunami scenarios, depths of inundation on dry land, and maximum velocity current distribution in inundation zones. The communities for inundation mapping are selected in coordination with the Alaska Division of Emergency Services with consideration to location, infrastructure, availability of bathymetric and topographic data, and community involvement.The communities of Homer and Seldovia are located in Kachemak Bay, which is one of the high-priority region for Alaska inundation mapping. We modeled two hypothetical earthquake scenarios as potential sources of tsunami waves that affect the Kachemak Bay communities. They represent both distant and local sources, and we model them using the multiple fault approach. Seward, a community in the Prince William Sound area, suffered an extensive damage and 12 fatalities during the 1964 tsunami. The most destructive waves in Seward were local slump-generated tsunamis. We consider several tsunami scenarios for Seward inundation mapping that include both tectonic and landslide sources.

Suleimani, E.; Hansen, R.; Marriott, D.; Combellick, R.

2004-05-01

95

2004 Tsunami survey in Comoros and Tanzania with inferences on tsunami risk in the Western Indian Ocean during future mega-thrust events  

Science.gov (United States)

We present a total of 59 new data points of run-up of the 2004 Sumatra tsunami in the Comoros and Tanzania, surveyed in 2006-2008 by International Tsunami Survey Teams. Run-up at the Northeastern tip of Grande Comore (6.8 m) is comparable to Socotra (6.1 m), and surpassed only in the Western Indian Ocean by the catastrophic values in Somalia (run-up 9 m; inundation 700 m). Run-up in Mayotte, and to a lesser extent Zanzibar, show considerable variations (from 1 to 5 m), attributed to the influence of the local structure of the reef surrounding these islands. By contrast, the unreefed islands of Anjouan and Moheli, and the mainland coast of Tanzania around Dar-es-Salaam, feature more consistent values in the 2 to 3 m range. The death toll in Tanzania is revised to at least 20. We then use the MOST code to simulate the propagation on the high seas of both the 2004 tsunami, and of potential future tsunamis under scenarios of mega earthquakes rupturing in the South Sumatra region; in particular, we consider the case of a probable event releasing the strain left over from the 1833 rupture after the 2007 Bengkulu earthquake. While these studies are not carried to the full extent of run-up calculations at individual sites, they give a general estimate of expectable hazard, relative to 2004, under the relevant scenarios, at 17 offshore virtual gauges strategically located from Oman to South Africa. We confirm more quantitatively the results of Okal and Synolakis (2008), namely that the change of directivity characteristics results in an increase of tsunami amplitude (with respect to 2004) at all sites South of Kenya (including Madagascar and the Mascarenes), while amplitudes at the Horn of Africa (Socotra, Somalia) remain large, due to focusing by individual bathymetric features. In short, potential earthquake sources along the Southern coast of Sumatra could result in higher wave heights than in 2004, along most of the Eastern shores of Africa, Madagascar and the Mascarenes.

Synolakis, C. E.; Okal, E. A.; Fritz, H. M.; Sladen, A.

2008-12-01

96

A Tsunami Fragility Assessment for Nuclear Power Plants in Korea  

Energy Technology Data Exchange (ETDEWEB)

Although Tsunami events were defined as an external event in 'PRA Procedure Guide (NUREG/CR- 2300)'after 1982, a Tsunami event was not considered in a design and construction of NPP before the Sumatra earthquake in 2004. But the Madras Atomic Power Station, a commercial nuclear power plant owned and operated by the Nuclear Power Corporation of India Limited (NPCIL), and located near Chennai, India, was affected by the tsunami generated by the 2004 Sumatra earthquake (USNRC 2008). The condenser cooling pumps of Unit 2 of the installation were affected due to flooding of the pump house and subsequent submergence of the seawater pumps by tsunami waves. The turbine was tripped and the reactor shut down. The unit was brought to a cold-shutdown state, and the shutdown-cooling systems were reported as operating safely. After this event, Tsunami hazards were considered as one of the major natural disasters which can affect the safety of Nuclear Power Plants. The IAEA performed an Extrabudgetary project for Tsunami Hazard Assessment and finally an International Seismic Safety Center (ISSC) established in IAEA for protection from natural disasters like earthquake, tsunami etc. For this reason, a tsunami hazard assessment method determined in this study. At first, a procedure for tsunami hazard assessment method was established, and second target equipment and structures for investigation of Tsunami Hazard assessment were selected. Finally, a sample fragility calculation was performed for one of equipment in Nuclear Power Plant.

Kim, Min Kyu; Choi, In Kil [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of); Kang, Keum Seok [Korea Electric Power Research Institute, Daejeon (Korea, Republic of)

2009-10-15

97

A Tsunami Fragility Assessment for Nuclear Power Plants in Korea  

International Nuclear Information System (INIS)

Although Tsunami events were defined as an external event in 'PRA Procedure Guide (NUREG/CR- 2300)'after 1982, a Tsunami event was not considered in a design and construction of NPP before the Sumatra earthquake in 2004. But the Madras Atomic Power Station, a commercial nuclear power plant owned and operated by the Nuclear Power Corporation of India Limited (NPCIL), and located near Chennai, India, was affected by the tsunami generated by the 2004 Sumatra earthquake (USNRC 2008). The condenser cooling pumps of Unit 2 of the installation were affected due to flooding of the pump house and subsequent submergence of the seawater pumps by tsunami waves. The turbine was tripped and the reactor shut down. The unit was brought to a cold-shutdown state, and the shutdown-cooling systems were reported as operating safely. After this event, Tsunami hazards were considered as one of the major natural disasters which can affect the safety of Nuclear Power Plants. The IAEA performed an Extrabudgetary project for Tsunami Hazard Assessment and finally an International Seismic Safety Center (ISSC) established in IAEA for protection from natural disasters like earthquake, tsunami etc. For this reason, a tsunami hazard assessment method determined in this study. At first, a procedure for tsunami hazard assessment method was established, and second target equipment and structures for investigation of Tsunami Hazard assessment were selected. Finally, a sample fragility calculation was perly, a sample fragility calculation was performed for one of equipment in Nuclear Power Plant

98

The Chiemgau Meteorite Impact And Tsunami Event (Southeast Germany): First Osl Dating  

Science.gov (United States)

A more exact dating of the Chiemgau meteorite impact in Bavaria, southeast Germany, that produced a large strewn field of more than 80 craters sized between a few meters and several hundred meters, may provide the indispensable fundament for evaluating its cultural implications and thus enable an extraordinary case study. A straightforward answer has not yet been provided due to e.g. scarce existence of diagnostic material, lack of specialised micromorphologists, absence of absolute dating data etc. Here we report on a first OSL dating applied to a catastrophic impact layer that features both impact ejecta and tsunami characteristics attributed to proposed falls of projectiles into Lake Chiemsee in the impact event. The OSL dating was conducted on a quartzite cobble and four sediment samples collected from an excavated archaeological stratigraphy at Lake Chiemsee that comprised also the impact layer. In a first approach the analyses were based on the assumption of zero luminescence resetting clock from the induced impact shock for the quartzite cobble, and a solar bleaching of tsunamigenerated sediments. Optically Stimulated Luminescence (OSL) was applied using the Single Aliquot Regeneration (SAR) protocol and relevant reliability criteria. For sediments the beta-TL method was also applied. Reported ages fall around the beginning of 2nd millennium BC. Special attention is given to the peculiar situation of OSL dating of material that may have been exposed to impact shock of strongly varying intensity, to excavation, ejection and ejecta emplacement, the latter overprinted by and mixed with tsunami transport processes resulting in possibly very complex bleaching scenarios largely differing from the original assumptions.

Liritzis, I.; Zacharias, N.; Polymeris, G. S.; Kitis, G.; Ernstson, K.; Sudhaus, D.; Neumair, A.; Mayer, W.; Rappenglück, M. A.; Rappenglück, B.

99

Generation of surface waves by an underwater moving bottom: Experiments and application to tsunami modelling  

CERN Document Server

We report laboratory experiments on surface waves generated in a uniform fluid layer whose bottom undergoes a sudden upward motion. Simultaneous measurements of the free-surface deformation and the fluid velocity field are focused on the role of the bottom kinematics in wave generation. We observe that the fluid layer transfers bottom motion to the free surface as a temporal high-pass filter coupled with a spatial low-pass filter. Both filter effects are usually neglected in tsunami warning systems. Our results display good agreement with a prevailing linear theory without fitting parameter. Based on our experimental data, we provide a new theoretical approach for the rapid kinematics limit that is applicable even for non-flat bottoms: a key step since most approaches assume a uniform depth. This approach can be easily appended to tsunami simulations under arbitrary topography.

Jamin, Timothée; Ruiz-Chavarría, Gerardo; Berhanu, Michael; Falcon, Eric

2014-01-01

100

Tsunami hazard in the Black Sea and the Azov Sea: a new tsunami catalogue  

Science.gov (United States)

Data on tsunamis occurring in the Black Sea and the Azov Sea from antiquity up to the present were updated, critically evaluated and compiled in the standard format developed since the 90's for the New European Tsunami Catalogue. Twenty nine events were examined but three of them, supposedly occurring in 557 AD, 815 AD and 1341 or 1343, were very likely falsely reported. Most of the remaining 26 events were generated in Crimea, offshore Bulgaria as well as offshore North Anatolia. For each of the 26 events examined, 22 events were classified as reliable ones receiving a score of 3 or 4 on a 4-grade reliability scale. Most of them were caused by earthquakes, such as the key event 544/545 of offshore Varna, but a few others were attributed either to aseismic earth slumps or to unknown causes. The tsunami intensity was estimated using the traditional 6-grade scale and the new 12-grade scale introduced by Papadopoulos and Imamura (2001). From 544/545 up to now, only two reliable events of high intensity K ? 7 have been reported, which very roughly indicates that the mean repeat time is ? 750 years. Five reliable tsunamis of moderate intensity 4 ? K tsunami events, the repeat times found are consistent with the theoretical expectations from size-frequency relations. However, in the Black Sea there is no evidence of tsunamis of very high intensity (K ? 10) such as the AD 365, 1303 and 1956 ones associated with large earthquakes occurring along the Hellenic arc and trench, Greece, or the 1908 one in Messina strait, Italy. This observation, along with the relatively low tsunami frequency, indicates that the tsunami hazard in the Black Sea is low to moderate but not negligible. The tsunami hazard in the Azov Sea is very low because of the very low seismicity but also because of the shallow water prevailing there. In fact, only three possible tsunami events have been reported in the Azov Sea.

Papadopoulos, G. A.; Diakogianni, G.; Fokaefs, A.; Ranguelov, B.

2011-03-01

 
 
 
 
101

A STUDY OF THE EFFECT OF PERMEABILITY OF ROCKS IN TSUNAMI GENERATION AND PROPAGATION BY SEISMIC FAULTING USING LINEARIZED SHALLOW – WATER WAVE THEORY  

Directory of Open Access Journals (Sweden)

Full Text Available The effect of permeability of rocks inside the ocean on Tsunami generation and Propagation is investigated. We study the nature of Tsunami build up and propagation using realistic curvilinear source models. The models are used to study the effect of permeability on tsunami amplitude amplification as a function on spreading velocity and rise time. Effect of permeability on Tsunami waveforms within the frame of the linearized shallow water wave theory for constant water depth are analyzed analytically using Transform methods. It is observed that in the region of highly permeable rocks the tsunami wave run is fast in comparison to low permeable rocks. The amplitude as a function of the propagated uplift length and width are analyzed. The cases of Tsunami-2011 (Japan, Tsunami- 2006 (Srilanka, and Tsunami-2006 (Madras have been demonstrated in the study.

PARUL SAXENA

2012-01-01

102

3D numerical investigation on landslide generated tsunamis around a conical island  

Science.gov (United States)

This paper presents numerical computations of tsunamis generated by subaerial and submerged landslides falling along the flank of a conical island. The study is inspired by the tsunamis that on 30th December 2002 attacked the coast of the volcanic island of Stromboli (South Tyrrhenian sea, Italy). In particular this paper analyzes the important feature of the lateral spreading of landside generated tsunamis and the associated flooding hazard. The numerical model used in this study is the full three dimensional commercial code FLOW-3D. The model has already been successfully used (Choi et al., 2007; 2008; Chopakatla et al, 2008) to study the interaction of waves and structures. In the simulations carried out in this work a particular feature of the code has been employed: the GMO (General Moving Object) algorithm. It allows to reproduce the interaction between moving objects, as a landslide, and the water. FLOW-3D has been firstly validated using available 3D experiments reproducing tsunamis generated by landslides at the flank of a conical island. The experiments have been carried out in the LIC laboratory of the Polytechnic of Bari, Italy (Di Risio et al., 2009). Numerical and experimental time series of run-up and sea level recorded at gauges located at the flanks of the island and offshore have been successfully compared. This analysis shows that the model can accurately represent the generation, the propagation and the inundation of landslide generated tsunamis and suggests the use of the numerical model as a tool for preparing inundation maps. At the conference we will present the validation of the model and parametric analyses aimed to investigate how wave properties depend on the landslide kinematic and on further parameters such as the landslide volume and shape, as well as the radius of the island. The expected final results of the research are precomputed inundation maps that depend on the characteristics of the landslide and of the island. Finally we will try to apply the code to a real life case i.e. the landslide tsunamis at the coast of the Stromboli island (Italy). SELECTED REFERENCES Choi, B.H. and D. C. Kim and E. Pelinovsky and S. B. Woo, 2007. Three dimensional simulation of tsunami run-up around conical island. Coastal Engineering 54,374 pp. 618-629. Chopakatla, S.C. and T.C. Lipmann and J.E. Richardson, 2008. Field verification of a computational fluid dynamics model for wave transformation and breaking in the surf zone. Journal of Waterway, Port, Coastal, and Ocean Engineering 134(2), pp. 71-80 Di Risio, M., P. De Girolamo, G. Bellotti, A. Panizzo, F. Aristodemo, M. G.Molfetta, and A. F. Petrillo (2009), Landslidegenerated tsunamis runup at the coast of a conical island: New physical model experiments. J. Geophys. Res., 114, C01009, doi:10.1029/2008JC004858 Flow Science, Inc, 2007. FLOW-3D User's Manual.

Montagna, Francesca; Bellotti, Giorgio

2010-05-01

103

Probabilistic Tsunami Hazard Assessment - Application to the Mediterranean Sea  

Science.gov (United States)

Following several large tsunami events around the world in the recent years, the tsunami hazard is becoming an increasing concern. The traditional way of assessing tsunami hazard has been through deterministic scenario calculations which provide the expected wave heights due to a given tsunami source, usually a worst-case scenario. For quantitative hazard and risk assessment, however, it is necessary to move towards a probabilistic framework. In this study we focus on earthquake generated tsunamis and present a scheme for probabilistic tsunami hazard assessment (PTHA). Our PTHA methodology is based on the use of Monte-Carlo simulations and follows probabilistic seismic hazard assessment methodologies closely. The PTHA is performed in four steps. First, earthquake and tsunami catalogues are analyzed in order to define a number of potential tsunami sources in the study area. For each of these sources, activity rates, maximum earthquake magnitude and uncertainties are assigned. Following, a synthetic earthquake catalogue is established, based on the information about the sources. The third step is to calculate multiple synthetic tsunami scenarios for all potentially tsunamigenic earthquakes in the synthetic catalogue. The tsunami scenarios are then combined at the fourth step to generate hazard curves and maps. We implement the PTHA methodology in the Mediterranean Sea, where numerous tsunami events have been reported in history. We derive a 100000 year-long catalog of potentially tsunamigenic earthquakes and calculate tsunami propagation scenarios for ca. 85000 M6.5+ earthquakes from the synthetic catalog. Results show that the highest tsunami hazard is attributed to the Eastern Mediterranean region, but that also the Western Mediterranean can experience significant tsunami waves for long return periods. Hazard maps will be presented for a range of probability levels together with hazard curves for selected critical locations.

Sorensen, M. B.; Spada, M.; Babeyko, A.; Wiemer, S.; Grünthal, G.

2009-12-01

104

On generation and propagation of tsunamis in a shallow running ocean  

Directory of Open Access Journals (Sweden)

Full Text Available A theory is presented of the generation and propagation of the two and the three dimensional tsunamis in a shallow running ocean due to the action of an arbitrary ocean floor or ocean surface disturbance. Integral solutions for both two and three dimensional problems are obtained by using the generalized Fourier and Laplace transforms. An asymptotic analysis is carried out for the investigation of the principal features of the free surface elevation. It is found that the propagation of the tsunamis depends on the relative magnitude of the given speed of the running ocean and the wave speed of the shallow ocean. When the speed of the running ocean is less than the speed of the shallow ocean wave, both the two and the three dimensional free surface elevation represent the generation and propagation of surface waves which decay asymptotically as t−12 for the two dimensional case and as t−1 for the three dimensional tsunamis. Several important features of the solution are discussed in some detail. As an application of the general theory, some physically realistic ocean floor disturbances are included in this paper.

Lokenath Debnath

1978-09-01

105

e+ e- event generator EPOCS  

International Nuclear Information System (INIS)

We present a Monte Carlo program EPOCS (Electron POsitron Collision Simulator), which generates e+e- events in high energy region that will be explored by TRISTAN project. Special emphasis is put on the effect of Z0 and possible top quark resonances. The user can control the simulation by selecting the energy and other parameters. Also he can easily incorpolate a new process and/or particles into the program. The central part of this report is a detailed description on the structure and the usage of the program. We would like to stress that the hadronization is based on a number of assumptions, which are made as clear as possible here. (author)

106

Predicting natural catastrophes tsunamis  

CERN Document Server

1. Tsunamis - Introduction - Definition of phenomenon - basic properties of the waves Propagation and dispersion Interaction with coasts - Geological and societal effects Origin of tsunamis - natural sources Scientific activities in connection with tsunamis. Ideas about simulations 2. Tsunami generation - The earthquake source - conventional theory The earthquake source - normal mode theory The landslide source Near-field observation - The Plafker index Far-field observation - Directivity 3. Tsunami warning - General ideas - History of efforts Mantle magnitudes and TREMOR algorithms The challenge of "tsunami earthquakes" Energy-moment ratios and slow earthquakes Implementation and the components of warning centers 4. Tsunami surveys - Principles and methodologies Fifteen years of field surveys and related milestones. Reconstructing historical tsunamis: eyewitnesses and geological evidence 5. Lessons from the 2004 Indonesian tsunami - Lessons in seismology Lessons in Geology The new technologies Lessons in civ...

CERN. Geneva

2005-01-01

107

Lessons Learned from the 2011 Great East Japan Tsunami: Performance of Tsunami Countermeasures, Coastal Buildings, and Tsunami Evacuation in Japan  

Science.gov (United States)

In 2011, Japan was hit by a tsunami that was generated by the greatest earthquake in its history. The first tsunami warning was announced 3 min after the earthquake, as is normal, but failed to estimate the actual tsunami height. Most of the structural countermeasures were not designed for the huge tsunami that was generated by the magnitude M = 9.0 earthquake; as a result, many were destroyed and did not stop the tsunami. These structures included breakwaters, seawalls, water gates, and control forests. In this paper we discuss the performance of these countermeasures, and the mechanisms by which they were damaged; we also discuss damage to residential houses, commercial and public buildings, and evacuation buildings. Some topics regarding tsunami awareness and mitigation are discussed. The failures of structural defenses are a reminder that structural (hard) measures alone were not sufficient to protect people and buildings from a major disaster such as this. These defenses might be able to reduce the impact but should be designed so that they can survive even if the tsunami flows over them. Coastal residents should also understand the function and limit of the hard measures. For this purpose, non-structural (soft) measures, for example experience and awareness, are very important for promoting rapid evacuation in the event of a tsunami. An adequate communication system for tsunami warning messages and more evacuation shelters with evacuation routes in good condition might support a safe evacuation process. The combination of both hard and soft measures is very important for reducing the loss caused by a major tsunami. This tsunami has taught us that natural disasters can occur repeatedly and that their scale is sometimes larger than expected.

Suppasri, Anawat; Shuto, Nobuo; Imamura, Fumihiko; Koshimura, Shunichi; Mas, Erick; Yalciner, Ahmet Cevdet

2013-06-01

108

The VOLNA code for the numerical modelling of tsunami waves: generation, propagation and inundation  

CERN Document Server

A novel tool for tsunami wave modelling is presented. This tool has the potential of being used for operational purposes: indeed, the numerical VOLNA code is able to handle the complete life-cycle of a tsunami (generation, propagation and run-up along the coast). The algorithm works on unstructured triangular meshes and, thus, can be run in arbitrary complex domains. It is often the case since natural coasts tend to be of fractal shape [Sapoval et al, 2004]. This paper contains the detailed description of the finite volume scheme implemented in the code. We explain the numerical treatment of the wet/dry transition. This point is crucial for accurate run-up computation. Most existing tsunami codes use semi-empirical techniques at this stage, which are not always sufficient. The main reason is that people evacuation is decided on the base of inundation maps which are produced with this type of numerical tools. Finally we present several realistic test cases that partially validate our algorithm. Comparisons wit...

Dutykh, Denys; Dias, Frédéric

2010-01-01

109

Preservation of Records, Knowledge and Memory across Generations (RK and M). Markers - Reflections on Inter-generational Warnings in the Form of Japanese Tsunami Stones  

International Nuclear Information System (INIS)

As states with nuclear power programmes are, or intend to become, engaged in planning the disposal of their high-level and/or long-lived radioactive waste in deep geological repositories, means to ensure that future generations will be aware of these repositories and not disturb them are being studied. Preservation of Records, Knowledge and Memory (RK and M) across Generations, launched in March 2010, is the relevant initiative under the NEA Radioactive Waste Management Committee in this area. Its several years of work and findings are documented online at www.oecdnea. org/rwm/rkm. A strategy of communicating important information to future generations must be based on several complementary means and approaches. Markers placed in the vicinity of closed repositories represent one potential component of this strategy. The RK and M initiative's glossary defines a marker as 'a long-lasting object that indicates an area of influence, power or danger. It is placed strategically at or near the site for immediate recognition or for discovery at a later time'. Markers are meant to reach future generations in the medium (a few hundred years) to long term (hundred thousand of years) and are conceived to be immobile (that is, in permanent association with a site), robust (in order to maximize survivability on its own) and provide messages that are likely to be understandable across generations. A marking system can range from a simple stone to a contrived and monumental multi-component system. The present report seeks to develop the understanding of the potential effectiveness of makers drawing from the study of the role that stone markers played in Japan during the Tohoku tsunami event of 2011. There are hundreds such markers placed at various epochs on Japan's north-eastern coast to warn future generations about the dangers of tsunamis. The existence of markers for recurrent, destructive events may help save lives, as in the case of the villages of Murohama and Aneyoshi. However, in most other cases, the markers did not help protect the population from the March 2011 tsunami. The villages of Murohama and Aneyoshi have shown interest in passing on the messages through oral history and in school education. However, it is worth asking whether these villages would have heeded the messages of the stone markers if the rest of society had given them other forms of assurance against tsunamis besides their own vigilance, for instance, if they had a tsunami wall or a functioning modern tsunami warning systems. This historical example illustrates that, over the course of several generations, markers informing and warning about disasters are of limited effectiveness for local protection. Despite the historical record and the widespread awareness of the danger that has materialised on a recurrent basis, the local population has, by and large, taken risks with or without the presence of markers. Reliance on new technologies, deferring responsibility to the authorities, and pursuit of short-term economic interests are three potential reasons for this behaviour. On the other hand, the March 2011 tsunami was a thousand-year event; it is questionable whether the population can be asked to live in the constant fear of and preparation for such a rare event, in Japan and in similarly latently dangerous areas around the world. The Japanese tsunami stones provide a rare example of warning markers and allow a number of considerations to be made for markers in the context of repository projects: - The longevity of stone markers in Japan - up to one thousand years - illustrates the possibility of survival of markers over similar timescales, especially in regions that are not subject to devastations from natural catastrophes. - Visible markers contribute to keeping memory alive. - Memory does not guarantee safety. The current international position that a geological repository should be safe by itself is confirmed by this study. - Memory may save lives under special circumstances and it should be fostered. - More than memory, knowledge saves lives. Markers

110

Modeling of Tsunami Generation and Propagation by a Spreading Curvilinear Seismic Faulting in Linearized Shallow-Water Wave Theory  

Directory of Open Access Journals (Sweden)

Full Text Available The processes of tsunami evolution during its generation in search for possible amplification mechanisms resulting from unilateral spreading of the sea floor uplift is investigated. We study the nature of the tsunami build up and propagation during and after realistic curvilinear source models represented by a slowly uplift faulting and a spreading slip-fault model. The models are used to study the tsunami amplitude amplification as a function of the spreading velocity and rise time. Tsunami waveforms within the frame of the linearized shallow water theory for constant water depth are analyzed analytically by transform methods (Laplace in time and Fourier in space for the movable source models. We analyzed the normalized peak amplitude as a function of the propagated uplift length, width and the average depth of the ocean along the propagation path.

Hossam S. Hassan

2010-05-01

111

Tsunamis on the Pacific Coast of Canada Recorded in 1994-2007  

Science.gov (United States)

In the last 15 years there have been 16 tsunami events recorded at tide stations on the Pacific Coast of Canada. Eleven of these events were from distant sources covering almost all regions of the Pacific, as well as the December 26, 2004 Sumatra tsunami in the Indian Ocean. Three tsunamis were generated by local or regional earthquakes and two were meteorological tsunamis. The earliest four events, which occurred in the period 1994-1996, were recorded on analogue recorders; these tsunami records were recently re-examined, digitized and thoroughly analysed. The other 12 tsunami events were recorded using digital high-quality instruments, with 1-min sampling interval, installed on the coast of British Columbia (B.C.) in 1998. All 16 tsunami events were recorded at Tofino on the outer B.C. coast, and some of the tsunamis were recorded at eight or more stations. The tide station at Tofino has been in operation for 100 years and these recent observations add to the dataset of tsunami events compiled previously by S.O. W igen (1983) for the period 1906-1980. For each of the tsunami records statistical analysis was carried out to determine essential tsunami characteristics for all events (arrival times, maximum amplitudes, frequencies and wave-train structure). The analysis of the records indicated that significant background noise at Langara, a key northern B.C. Tsunami Warning station located near the northern end of the Queen Charlotte Islands, creates serious problems in detecting tsunami waves. That station has now been moved to a new location with better tsunami response. The number of tsunami events observed in the past 15 years also justified re-establishing a tide gauge at Port Alberni, where large tsunami wave amplitudes were measured in March 1964. The two meteorological events are the first ever recorded on the B.C. coast. Also, there have been landslide generated tsunami events which, although not recorded on any coastal tide gauges, demonstrate, along with the recent investigation of a historical catastrophic event, the significant risk that landslide generated tsunami pose to coastal and inland regions of B.C.

Stephenson, Frederick E.; Rabinovich, Alexander B.

2009-02-01

112

Tsunami Casualty Model  

Science.gov (United States)

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

Yeh, H.

2007-12-01

113

Adaptive triangular discontinuous Galerkin schemes for tsunami propagation and inundation  

Science.gov (United States)

A tsunami simulation framework is presented, which is based on adaptive triangular meshes and a finite element discontiuous Galerkin discretization. This approach allows for high local resolution and geometric accuracy, while maintaining the opportunity to simulate large spatial domains. The dynamically adaptive mesh is generated by the grid library amatos, which is based on a conforming tree based refinement strategy. While the tsunami propagation in the deep ocean is well represented by the nonlinear shallow water equations, special interest is given to the near-shore characteristics of the flow. For this purpose a new mass-conservative well-balanced inundation scheme is developed. This work is part of the ASCETE (Advanced Simulation of Coupled Earthquake and Tsunami Events) project, which aims to better understand the generation of tsunami events. In this course, a simulation framework is developed which couples physics-based rupture generation with hydrodynamic tsunami propagation and inundation.

Vater, Stefan; Behrens, Jörn

2014-05-01

114

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

Science.gov (United States)

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.

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

2014-02-01

115

MODELING THE ASIAN TSUNAMI EVOLUTION AND PROPAGATION WITH A NEW GENERATION MECHANISM AND A NON-LINEAR DISPERSIVE WAVE MODEL  

Directory of Open Access Journals (Sweden)

Full Text Available A common approach in modeling the generation and propagation of tsunami is based on the assumption of a kinematic vertical displacement of ocean water that is analogous to the ocean bottom displacement during a submarine earthquake and the use of a non-dispersive long-wave model to simulate its physical transformation as it radiates outward from the source region. In this study, a new generation mechanism and the use of a highly-dispersive wave model to simulate tsunami inception, propagation and transformation are proposed. The new generation model assumes that transient ground motion during the earthquake can accelerate horizontal currents with opposing directions near the fault line whose successive convergence and divergence generate a series of potentially destructive oceanic waves. The new dynamic model incorporates the effects of earthquake moment magnitude, ocean compressibility through the buoyancy frequency, the effects of focal and water depths, and the orientation of ruptured fault line in the tsunami magnitude and directivity.For tsunami wave simulation, the nonlinear momentum-based wave model includes important wave propagation and transformation mechanisms such as refraction, diffraction, shoaling, partial reflection and transmission, back-scattering, frequency dispersion, and resonant wave-wave interaction. Using this model and a coarse-resolution bathymetry, the new mechanism is tested for the Indian Ocean tsunami of December 26, 2004. A new flooding and drying algorithm that consider waves coming from every direction is also proposed for simulation of inundation of low-lying coastal regions.It is shown in the present study that with the proposed generation model, the observed features of the Asian tsunami such as the initial drying of areas east of the source region and the initial flooding of western coasts are correctly simulated. The formation of a series of tsunami waves with periods and lengths comparable to observations are also well simulated with the new generation model. Furthermore, the shoaling behavior of the tsunami waves during flooding of dry land was also simulated by the new run-up algorithm. Finally, the new generation and propagation models can explain the combined and independent effects of various factors in tsunami generation and transformation taking into consideration the properties of the ocean and the geologic disturbance.

Paul C. Rivera

2006-01-01

116

Recent Tsunamis That Affected the Japanese Coasts and Evaluation of JMA's Tsunami Warnings  

Science.gov (United States)

During the last two years (Sep 2006 to Aug 2008), Japan Meteorological Agency (JMA) issued tsunami advisories or warnings for eight events. Tsunami estimations in the advisories or warnings are considered appropriate for six cases. No tsunami was confirmed for the other two cases, one of which was thought to be a quite peculiar case. The November 2006 and January 2007 Kuril earthquakes, for which tsunami warnings were issued on the Hokkaido coasts, impelled JMA to improve its methods in estimating tsunamis. The JMA magnitude (M) was larger for the 2007 earthquake than the 2006 event, but other magnitude scales as well as the observed tsunamis were smaller (Fujii and Satake, 2008, BSSA). The long duration of these Kuril tsunamis were due to reflected wave at Emperor seamount chain (Koshimura et al., 2007, GRL). These features have become to be considered in the current JMA's system. The Noto-hanto earthquake (M 6.9) on March 25 in 2007 generated a small (earthquake. On April 20, tsunami advisory was issued following an earthquake near Miyakojima, but no tsunami was recorded. The JMA magnitude was 6.7, but the moment magnitude (Mw) was 6.3 (cf. Global CMT catalog). It is a difficult case to evaluate the magnitude accurately as this is islands region. On July 16, the Niigata-ken Chuetsu-oki earthquake (M 6.8) caused moderate tsunami without any damage; the amplitude was up to a few tens of cm at most tidal stations while one station located nearby the source region recorded 1m. JMA issued tsunami advisory within 1 min of the earthquake. On August 2, following a shallow earthquake off southern Sakhalin coast (Mw 6.2), JMA at first did not issue advisory or warning because the estimations did not exceed the criteria for advisory. But a sea level fluctuation was observed at a few tide stations on the Japanese coast, then, JMA issued tsunami advisory for the northern coast of Hokkaido. The post-event analysis showed that the sea level disturbances recorded at Rumoi does not match with the numerical simulation, hence considered as meteorological origin. On August 16, for the great earthquake (Mw 8.0) off Peru coast, JMA issued tsunami advisory, based on the tsunami numerical simulation and actual tsunami data in Hawaii. The tsunami heights recorded on tide gauges were 0.2 m or less in Japan. On May 8, 2008, an earthquake off Ibaraki (M 7.0) occurred and JMA did not issue tsunami advisory. Instead, JMA issued a tsunami forecast, which informed that the maximum tsunami height would be below 0.2m and that such tsunami would not cause damage. Some tide stations recorded very weak tsunami, around 0.1m. On July 19, an earthquake (M 6.6) off Fukushima prefecture caused tsunami up to 0.2 m. JMA issued tsunami advisory for this event.

Satake, K.; Hasegawa, Y.; Nishimae, Y.; Igarashi, Y.

2008-12-01

117

Probabilistic tsunami hazard assessment for the Mediterranean Sea  

Science.gov (United States)

Following several large tsunami events around the world in the recent years, the tsunami hazard in the Mediterranean region is becoming an increasing concern. The traditional way of assessing tsunami hazard has been through deterministic scenario calculations which provide the expected wave heights due to a given tsunami source. For quantitative hazard and risk assessment, however, it is necessary to move towards a probabilistic framework. In this study we focus on earthquake generated tsunamis and present a scheme for probabilistic tsunami hazard assessment (PTHA) for the Mediterranean Sea. Our PTHA methodology is based on the use of Monte-Carlo simulations and follows probabilistic seismic hazard assessment methodologies closely. The PTHA is performed in four steps: First, earthquake and tsunami catalogues are analyzed in order to define a number of potential tsunami sources in the study area. For each of these sources, activity rates, maximum earthquake magnitude and uncertainties are assigned. Following, a synthetic earthquake catalogue is established, based on the information about the sources. The third step is to calculate multiple synthetic tsunami scenarios for all potentially tsunamigenic earthquakes in the synthetic catalogue. The tsunami scenarios are then combined in the fourth step to generate hazard maps for the Mediterranean region and hazard curves for selected sites. The implementation of the PTHA in the Mediterranean Sea will be described. For a 10000 year long synthetic catalogue, ca. 8500 potentially tsunamigenic earthquakes are defined for which propagation scenarios are calculated. Hazard maps based on these scenarios will be presented together with hazard curves for selected locations.

Sørensen, M. B.; Babeyko, A.; Spada, M.; Wiemer, S.; Grünthal, G.

2009-04-01

118

Tsunamis vs meteotsunamis at the Balearic Islands  

Science.gov (United States)

Tsunamis and meteotsunamis have a very similar behaviour near the coast, being both strongly affected by the topography. Despite they have a clear different origin: seismic (tsunamis) and atmospheric disturbances (meteotsunamis), once generated, they present many similarities, particularly when recorded at the coast due to the strong influence of coastal resonance effects. But propagation over the shelf may be somehow different. The long wave generated after the eartquake propagates freely without any additional forcing and the meteotsunami requires some resonance process between the atmosphere and the ocean in order to optimally transfer the atmospheric energy into the ocean. Meteotsunamis are a very common phenomenon in the region of the Balearic Islands (western Mediterranean) where they are locally known as 'rissaga' but this region is not sismically active and tsunamis only occur in very rare ocasions. However, On 21 May 2003 a submarine earthquake occurred near Algiers producing a tsunami that propagated northward and reached the Balearic Islands and the Levantine coast of the Iberian Peninsula. This event represents a unique oportunity to compare tsunami and meteotsunami characteristics in this region. We separate source and topographic effects from coastal measurements during the tsunami generated in May 2003 and during some meteotsunamis recorded in the region this year. Available data allow to investigating the response of different events at the same coastal station and to compare them with the behaviour of the same event at nearby stations.

Monserrat, Sebastian; Mar Vich, Maria-Del

2010-05-01

119

MadEvent: automatic event generation with MadGraph  

International Nuclear Information System (INIS)

We present a new multi-channel integration method and its implementation in the multi-purpose event generator MadEvent, which is based on MadGraph. Given a process, MadGraph automatically identifies all the relevant subprocesses, generates both the amplitudes and the mappings needed for an efficient integration over the phase space, and passes them to MadEvent. As a result, a process-specific, stand-alone code is produced that allows the user to calculate cross sections and produce unweighted events in a standard output format. Several examples are given for processes that are relevant for physics studies at present and forthcoming colliders. (author)

120

Numerical modeling of landslide-generated tsunami using adaptive unstructured meshes  

Science.gov (United States)

Landslides impacting into or occurring under water generate waves, which can have devastating environmental consequences. Depending on the characteristics of the landslide the waves can have significant amplitude and potentially propagate over large distances. Linear models of classical earthquake-generated tsunamis cannot reproduce the highly nonlinear generation mechanisms required to accurately predict the consequences of landslide-generated tsunamis. Also, laboratory-scale experimental investigation is limited to simple geometries and short time-scales before wave reflections contaminate the data. Computational fluid dynamics models based on the nonlinear Navier-Stokes equations can simulate landslide-tsunami generation at realistic scales. However, traditional chessboard-like structured meshes introduce superfluous resolution and hence the computing power required for such a simulation can be prohibitively high, especially in three dimensions. Unstructured meshes allow the grid spacing to vary rapidly from high resolution in the vicinity of small scale features to much coarser, lower resolution in other areas. Combining this variable resolution with dynamic mesh adaptivity allows such high resolution zones to follow features like the interface between the landslide and the water whilst minimising the computational costs. Unstructured meshes are also better suited to representing complex geometries and bathymetries allowing more realistic domains to be simulated. Modelling multiple materials, like water, air and a landslide, on an unstructured adaptive mesh poses significant numerical challenges. Novel methods of interface preservation must be considered and coupled to a flow model in such a way that ensures conservation of the different materials. Furthermore this conservation property must be maintained during successive stages of mesh optimisation and interpolation. In this paper we validate a new multi-material adaptive unstructured fluid dynamics model against the well-known Lituya Bay landslide-generated wave experiment and case study [1]. In addition, we explore the effect of physical parameters, such as the shape, velocity and viscosity of the landslide, on wave amplitude and run-up, to quantify their influence on the landslide-tsunami hazard. As well as reproducing the experimental results, the model is shown to have excellent conservation and bounding properties. It also requires fewer nodes than an equivalent resolution fixed mesh simulation, therefore minimising at least one aspect of the computational cost. These computational savings are directly transferable to higher dimensions and some initial three dimensional results are also presented. These reproduce the experiments of DiRisio et al. [2], where an 80cm long landslide analogue was released from the side of an 8.9m diameter conical island in a 50 × 30m tank of water. The resulting impact between the landslide and the water generated waves with an amplitude of 1cm at wave gauges around the island. The range of scales that must be considered in any attempt to numerically reproduce this experiment makes it an ideal case study for our multi-material adaptive unstructured fluid dynamics model. [1] FRITZ, H. M., MOHAMMED, F., & YOO, J. 2009. Lituya Bay Landslide Impact Generated Mega-Tsunami 50th Anniversary. Pure and Applied Geophysics, 166(1), 153-175. [2] DIRISIO, M., DEGIROLAMO, P., BELLOTTI, G., PANIZZO, A., ARISTODEMO, F.,

Wilson, Cian; Collins, Gareth; Desousa Costa, Patrick; Piggott, Matthew

2010-05-01

 
 
 
 
121

International year of planet earth 7. Oceans, submarine land-slides and consequent tsunamis in Canada  

Science.gov (United States)

Canada has the longest coastline and largest continental margin of any nation in the World. As a result, it is more likely than other nations to experience marine geohazards such as submarine landslides and consequent tsunamis. Coastal landslides represent a specific threat because of their possible proximity to societal infrastructure and high tsunami potential; they occur without warning and with little time lag between failure and tsunami impact. Continental margin landslides are common in the geologic record but rare on human timescales. Some ancient submarine landslides are massive but more recent events indicate that even relatively small slides on continental margins can generate devastating tsunamis. Tsunami impact can occur hundreds of km away from the source event, and with less than 2 hours warning. Identification of high-potential submarine landslide regions, combined with an understanding of landslide and tsunami processes and sophisticated tsunami propagation models, are required to identify areas at high risk of impact.

Mosher, D. C.

2009-01-01

122

Linearized Shallow-water Wave Theory of Tsunami Generation and Propagation by Three-dimensional Stochastic Seismic Bottom Topography  

Directory of Open Access Journals (Sweden)

Full Text Available Tsunami generation and propagation resulting from lateral spreading of a stochastic seismic fault source model driven by two Gaussian white noises in the x- and y- directions are investigated. Tsunami waveforms within the frame of the linearized shallow water theory for constant water depth are analyzed analytically by transform methods (Laplace in time and Fourier in space for the random sea floor uplift represented by a sliding Heaviside step function under the influence of two Gaussian white noise processes in the x- and y- directions. This model is used to study the tsunami amplitude amplification under the effect of the noise intensity and rise times of the stochastic fault source model. The amplification of tsunami amplitudes builds up progressively as time increases during the generation process due to wave focusing while the maximum wave amplitude decreases with time during the propagation process due to the geometric spreading and also due to dispersion. We derived and analyzed the mean and variance of the random tsunami waves as a function of the time evolution along the generation and propagation path.

M.A. Omar

2014-05-01

123

Sensitivity Analysis and Bayesian Inference of Manning's N Friction Coefficient during a Tsunami Event Using Polynomial Chaos  

Science.gov (United States)

We present an efficient method to perform a sensitivity analysis of the Manning's N friction coefficient in the event of tsunamis. We also infer Manning's N friction coefficient using water surface elevation data obtained during Tohoku tsunami. We characterize the Manning's friction coefficient by three different parameters assumed constant in three regions: N1 on-shore, N2 near-shore and N3 deep-water. The efficiency of our approach stems from the use of polynomial chaos expansions to build an inexpensive surrogate for the numerical tsunami GeoClaw model that can be used to perform the sensitivity analysis. The surrogate also reduces the computational burden of the Markov Chain Monte-Carlo sampling needed for the Bayesian inference. Our objective is to sharpen three initial estimates of the three uncertain parameters. Our results indicate that Manning's N friction coefficients have a Maximum-A-Posteriori (MAP) values of N2=0.011 and N3=0.185 while for N1 no meaningful MAP value can be determined using the available data.

Sraj, Ihab; Mandli, Kyle; Dawson, Clint; Hoteit, Ibrahim

2014-05-01

124

Observations and Modeling of the August 27, 2012 Earthquake and Tsunami affecting El Salvador and Nicaragua  

Science.gov (United States)

On 27 August 2012 (04:37 UTC, 26 August 10:37 p.m. local time) a magnitude M w = 7.3 earthquake occurred off the coast of El Salvador and generated surprisingly large local tsunami. Following the event, local and international tsunami teams surveyed the tsunami effects in El Salvador and northern Nicaragua. The tsunami reached a maximum height of ~6 m with inundation of up to 340 m inland along a 25 km section of coastline in eastern El Salvador. Less severe inundation was reported in northern Nicaragua. In the far-field, the tsunami was recorded by a DART buoy and tide gauges in several locations of the eastern Pacific Ocean but did not cause any damage. The field measurements and recordings are compared to numerical modeling results using initial conditions of tsunami generation based on finite-fault earthquake and tsunami inversions and a uniform slip model.

Borrero, Jose C.; Kalligeris, Nikos; Lynett, Patrick J.; Fritz, Hermann M.; Newman, Andrew V.; Convers, Jaime A.

2014-02-01

125

Tsunami Impact Study in the U. S. Atlantic Coasts and Caribbean Shores due to the 1755 Great Lisbon Earthquake  

Science.gov (United States)

The Indian Ocean tsunami of 24 December 2004 has changed the perception of a tsunami as a low-risk hazard for coastal infrastructures. The Nuclear Regulation Commission (NRC) plans to evaluate the tsunami risk for existing and potential Nuclear Power Plants in the U. S. east coast and Gulf of Mexico posed by tsunami sources in the Atlantic and the Caribbean. A key action is the modeling assessment of the trans-Atlantic tsunami impact caused by the 1755 Lisbon earthquake, one of the most hazardous, yet understudied, historical earthquake-generated tsunami events in the Atlantic. Using high-resolution inundation models, the present study focuses on assessing the distant impact of 1755 tsunami for multiple sites in the U. S. Atlantic coast and Caribbean, specifically its nearshore dynamics in the harbors, inlets and waterways. While helping to identify the tsunami source due to the Lisbon earthquake, this application emphasizes on the significance of the tsunami magnitude, source location, bathymetry and topography in understanding the progression of tsunami waves offshore and nearshore. The research also highlights the modeling investigation of tsunami wave transformation over the continental shelf from the open ocean to the coasts, which may provide useful guidance for regional and local tsunami forecast. This study sets an example of extending NOAA's existing tsunami forecast system to identify tsunami vulnerability for global coastal communities at risk.

Wei, Y.; Titov, V.; Arcas, D.; Gica, E.; Moore, C.

2008-12-01

126

Evaluation on coolability of the reactor core in Monju by natural circulation under earthquake and subsequent tsunami event  

International Nuclear Information System (INIS)

Conclusion: ? This study clarified that the decay heat of the core can be safely removed in Monju by the natural circulations of the coolant sodium even during an SBO event induced by an earthquake and a subsequent tsunami, as far as the sodium coolant flow circuits are intact and secured. ? Moreover parametric numerical simulations revealed that the natural circulations will be maintained for a sufficiently long period of time and the safety of the reactor will be ensured even under wide range of varied conditions

127

Hazard assessment for a submarine landslide generated local-source tsunami from Kaikoura Canyon  

Science.gov (United States)

The Kaikoura Canyon, sediment sink for the Canterbury rivers north of Christchurch, comes to within 500 meters of shore at Goose Bay and accumulates approximately 1.5x106 m3 of sediment each year (Lewis and Barnes, 1999). This sediment, which has accumulated to about seventy meters in thickness (Walters et al., 2006), exhibits tensional fractures, is located in a tectonically active area and could result in catastrophic failure and potentially a local-source tsunami (Lewis and Banes, 1999; Lewis, 1998; Walters et al, 2006). Evidence suggests that this may have happened in the last two hundred years (Lewis, 1998; Lewis and Barnes 1999) and with a return period on the nearby Alpine and Hope faults also in the range of a one to two hundred years (Walters et al, 2006) could happen again relatively soon. A review of the historical record and oral traditions for Kaikoura shows that historically Kaikoura has been affected by 11 events of which 10 are from distant sources and one, though debatable, is possibly from a local source. There are some preserved traditions for the Kaikoura area. These taniwha stories from near Oaro and from the Lyell Creek have been repeated and changed though time though the general essence remains the same. These taniwha legends, though not conclusive, indicate a dangerous shoreline where people have been killed in the past, possibly by flooding or tsunami. Archaeological investigations at Kaikoura found evidence of a Maori occupational layers interrupted by water-worn stones, a "lens of clean gravel between occupation layers" and in other areas of the excavation, the gravels separate discontinuous periods of occupation (Fomison 1963; Foster, 2006). Additionally "pea-gravel" sized greywacke pebbles were found dispersed throughout sections of the South Bay shore platforms, though they were attributesd to slopewash (Duckmanton, 1974) this is less likely since the nearby hills are limestone. A geological investigation along the Kaikoura Coast, at five sites from South Bay to Oara, corroborates this. At four of the sites a similar greywacke pebble bearing layer was found which was not present at test sites to the North and South of the peninsula (Kiwa Rd Campsites and Claverly respectively). These deposits contain diatoms indicating marine provenance. Surveys of Kaikoura peninsula households and businesses showed low levels of preparedness for a local source event. In regards to local-source tsunamis the district council has indicated that they "are unpredictable [and] it is impractical to include rules to mitigate their effects. Instead, the Council is committed to a Civil Defence network which provides an educative role and which sets in place a process for dealing with the results of any tsunami" (Kaikoura District Plan, 2010). Plans and an education strategy need to be formulated and implemented. They need to address considerations such as the fact that about 60% of those surveyed expect some sort of siren warning and the limitations inherent in such a warning system along with signage and public tsunami hazard maps and evacuation zones.

DuBois, J.

2012-04-01

128

Understanding the Response of the Ionosphere to Atmospheric Waves Generated by Tsunamis and Other Geophysical Disturbances  

Science.gov (United States)

We present results from the coupling of the ground-to-space atmospheric spectral gravity wave model of Drob et al., (2012) with the SAMI3/ESF first-principles ionosphere model of Huba et al., (2009). This coupled physics-based simulation capability provides a means to explore, understand, and characterize the various factors that determine the response of the ionosphere to atmospheric gravity waves generated by tsunamis and other geophysical seismo-acoustic phenomena. These factors include; 1) the wavelength, frequency content, and propagation direction of the ocean/ground motion; 2) the seasonal and geographic factors which determined the anisotropic atmospheric background wind filtering and thermospheric gravity-wave dissipation processes; 3) the seasonal, geographic, local-time, and solar flux conditions that determine the background electron density and ionosphere conductivity profiles; and 4) the relationship of the atmospheric perturbations with respect to the geomagnetic field. For example, by comparing the results of simulations with and without gravity wave-perturbations we explore the effect of zonal, meridional, and vertical gravity wave wind perturbations across a range of geomagnetic latitudes (and thus geomagnetic pitch angle) to the resulting plasma velocity perturbations along the corresponding geomagnetic fields lines, as well as to the subsequent perturbations of total electron content (TEC). For comparable atmospheric gravity wave amplitudes, we find TEC variations of ~ +/- 0.1TECU (1 TECU = 10^16 m^2) which are consistent with observations made during the 11 March 2001 tsunami. This work sponsored by the Office of Naval Research.

Drob, Douglas; Huba, Joseph; Broutman, David

2014-05-01

129

The Catalog of Event Data of the Operational Deep-ocean Assessment and Reporting of Tsunamis (DART) Stations at the National Data Buoy Center  

Science.gov (United States)

DART systems are a critical component of the tsunami warning system as they provide the only real-time, in situ, tsunami detection before landfall. DART systems consist of a surface buoy that serves as a position locater and communications transceiver and a Bottom Pressure Recorder (BPR) on the seafloor. The BPR records temperature and pressure at 15-second intervals to a memory card for later retrieval for analysis and use by tsunami researchers, but the BPRs are normally recovered only once every two years. The DART systems also transmit subsets of the data, converted to an estimation of the sea surface height, in near real-time for use by the tsunami warning community. These data are available on NDBC's webpages, http://www.ndbc.noaa.gov/dart.shtml. Although not of the resolution of the data recorded to the BPR memory card, the near real-time data have proven to be of value in research applications [1]. Of particular interest are the DART data associated with geophysical events. The DART BPR continuously compares the measured sea height with a predicted sea-height and when the difference exceeds a threshold value, the BPR goes into Event Mode. Event Mode provides an extended, more frequent near real-time reporting of the sea surface heights for tsunami detection. The BPR can go into Event Mode because of geophysical triggers, such as tsunamis or seismic activity, which may or may not be tsunamigenic. The BPR can also go into Event Mode during recovery of the BPR as it leaves the seafloor, or when manually triggered by the Tsunami Warning Centers in advance of an expected tsunami. On occasion, the BPR will go into Event Mode without any associated tsunami or seismic activity or human intervention and these are considered "False'' Events. Approximately one- third of all Events can be classified as "False". NDBC is responsible for the operations, maintenance, and data management of the DART stations. Each DART station has a webpage with a drop-down list of all Events. NDBC maintains the non-geophysical Events in order to maintain the continuity of the time series records. In 2007, NDBC compiled all DART Events that occurred while under NDBC's operational control and made an assessment on their validity. The NDBC analysts performed the assessment using the characteristics of the data time series, triggering criteria, and associated seismic events. The compilation and assessments are catalogued in a NDBC technical document. The Catalog also includes a listing of the one-hour, high-resolution data, retrieved remotely from the BPRs that are not available on the web pages. The Events are classified by their triggering mechanism and listed by station location and, for those Events associated with geophysical triggers, they are listed by their associated seismic events. The Catalog provides researchers with a valuable tool in locating, assessing, and applying near real-time DART data to tsunami research and will be updated following DART Events. A link to the published Catalog can be found on the NDBC DART website, http://www.ndbc.noaa.gov/dart.shtml. Reference: [1] Gower, J. and F. González (2006), U.S. Warning System Detected the Sumatra Tsunami, Eos Trans. AGU, 87(10), 105-112.

Bouchard, R.; Locke, L.; Hansen, W.; Collins, S.; McArthur, S.

2007-12-01

130

Development of an online tool for tsunami inundation simulation and tsunami loss estimation  

Science.gov (United States)

The devastating impacts of the 2004 Indian Ocean tsunami highlighted the need for an effective end-to-end tsunami early warning system in the region that connects the scientific components of warning with preparedness of institutions and communities to respond to an emergency. Essential to preparedness planning is knowledge of tsunami risks. In this study, development of an online tool named “INSPIRE” for tsunami inundation simulation and tsunami loss estimation is presented. The tool is designed to accommodate various accuracy levels of tsunami exposure data which will support the users to undertake preliminary tsunami risk assessment from the existing data with progressive improvement with the use of more detailed and accurate datasets. Sampling survey technique is introduced to improve the local vulnerability data with lower cost and manpower. The performance of the proposed methodology and the INSPIRE tool were tested against the dataset in Kamala and Patong municipalities, Phuket province, Thailand. The estimated building type ratios from the sampling survey show the satisfactory agreement with the actual building data at the test sites. Sub-area classification by land use can improve the accuracy of the building type ratio estimation. For the resulting loss estimation, the exposure data generated from detailed field survey can provide the agreeable results when comparing to the actual building damage recorded for the Indian Ocean tsunami event in 2004. However, lower accuracy exposure data derived from sampling survey and remote sensing can still provide a comparative overview of estimated loss.

Srivihok, P.; Honda, K.; Ruangrassamee, A.; Muangsin, V.; Naparat, P.; Foytong, P.; Promdumrong, N.; Aphimaeteethomrong, P.; Intavee, A.; Layug, J. E.; Kosin, T.

2014-05-01

131

Source processes for the probabilistic assessment of tsunami hazards  

Science.gov (United States)

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.

Geist, Eric L.; Lynett, Patrick J.

2014-01-01

132

Source Processes for the Probabilistic Assessment of Tsunami Hazards  

Directory of Open Access Journals (Sweden)

Full Text Available 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.

Eric L. Geist

2014-06-01

133

The Pacific Tsunami Warning Center's Response to the Tohoku Earthquake and Tsunami  

Science.gov (United States)

The largest Pacific basin earthquake in 47 years, and also the largest magnitude earthquake since the Sumatra 2004 earthquake, struck off of the east coast of the Tohoku region of Honshu, Japan at 5:46 UTC on 11 March 2011. The Tohoku earthquake (Mw 9.0) generated a massive tsunami with runups of up to 40m along the Tohoku coast. The tsunami waves crossed the Pacific Ocean causing significant damage as far away as Hawaii, California, and Chile, thereby becoming the largest, most destructive tsunami in the Pacific Basin since 1960. Triggers on the seismic stations at Erimo, Hokkaido (ERM) and Matsushiro, Honshu (MAJO), alerted Pacific Tsunami Warning Center (PTWC) scientists 90 seconds after the earthquake began. Four minutes after its origin, and about one minute after the earthquake's rupture ended, PTWC issued an observatory message reporting a preliminary magnitude of 7.5. Eight minutes after origin time, the Japan Meteorological Agency (JMA) issued its first international tsunami message in its capacity as the Northwest Pacific Tsunami Advisory Center. In accordance with international tsunami warning system protocols, PTWC then followed with its first international tsunami warning message using JMA's earthquake parameters, including an Mw of 7.8. Additional Mwp, mantle wave, and W-phase magnitude estimations based on the analysis of later-arriving seismic data at PTWC revealed that the earthquake magnitude reached at least 8.8, and that a destructive tsunami would likely be crossing the Pacific Ocean. The earthquake damaged the nearest coastal sea-level station located 90 km from the epicenter in Ofunato, Japan. The NOAA DART sensor situated 600 km off the coast of Sendai, Japan, at a depth of 5.6 km recorded a tsunami wave amplitude of nearly two meters, making it by far the largest tsunami wave ever recorded by a DART sensor. Thirty minutes later, a coastal sea-level station at Hanasaki, Japan, 600 km from the epicenter, recorded a tsunami wave amplitude of nearly three meters. The evacuation of Hawaii's coastlines commenced at 7:31 UTC. Concurrent with this tsunami event, a widely-felt Mw 4.6 earthquake occurred beneath the island of Hawai`i at 8:58 UTC. PTWC responded within three minutes of origin time with a Tsunami Information Statement stating that the Hawaii earthquake would not generate a tsunami. After issuing 27 international tsunami bulletins to Pacific basin countries, and 16 messages to the State of Hawaii during a period of 25 hours after the event began, PTWC concluded its role during the Tohoku tsunami event with the issuance of the corresponding warning cancellation message at 6:36 UTC on 12 March 2011. During the following weeks, however, the PTWC would continue to respond to dozens of aftershocks related to the earthquake. We will present a complete timeline of PTWC's activities, both domestic and international, during the Tohoku tsunami event. We will also illustrate the immense number of website hits, phone calls, and media requests that flooded PTWC during the course of the event, as well as the growing role social media plays in communicating tsunami hazard information to the public.

Weinstein, S. A.; Becker, N. C.; Shiro, B.; Koyanagi, K. K.; Sardina, V.; Walsh, D.; Wang, D.; McCreery, C. S.; Fryer, G. J.; Cessaro, R. K.; Hirshorn, B. F.; Hsu, V.

2011-12-01

134

The fifth model for the huge tsunami generation off northwest Sumatra during the 2004 Sumatra-Andaman earthquake  

Science.gov (United States)

The 2004 Mw 9.2 Sumatra-Andaman earthquake caused a huge tsunami of more than 20 m on average along the west coast of Aceh. Four hypothetical models have been proposed for tsunami generation. The first model is that coseismic slip along the Sumatran megathrust is responsible for generation of the huge tsunami [e.g.,Henstock et al., 2006]. In this case, however, an additional tsunami generation mechanism such as inelastic deformation of soft accretionary sediment may be needed [Seno and Hirata, 2007]. The second model is that the most trenchward splay fault branching updip from the megathrust displaced coseismically [Soh et al., 2005; Seeber et al., 2007]. Splay faults can generate larger tsunamis, primarily because of their steeper dip. The third model is that the most landward splay fault, located at the eastern margin of the Sumatran outer-arc high, displaced coseismically [Sibuet et al., 2007]. The fourth model is that the West Andaman Fault, just west of the Aceh (forearc) basin, displaced coseismically [Plafker et al., 2005, 2006], though ROV diving surveys did not find any signature of coseismic fault motion along this fault [NT0502 scientific party, 2005; SEATOS scientific party, 2005]. Recent studies help constrain possible 2004 tsunami sources off northwest Sumatra. Coseismic slip limited to the deeper (landward) part of the megathrust cannot explain the observed Sea Surface Heights [Geist et al., 2007], indicating that the rupture reached the more trenchward portion of the fault. Calculated tsunami backward wave-fronts suggest that the trenchward boundary of the tsunami source off northwest Sumatra was located near the accretionary prism toe and that long-wave-approximated, maximum uplift area was located in the middle of the outer-arc high [e.g., Fine et al., 2005]. Array analysis of short-period tsunami dispersed waves, observed with hydrophone arrays in the Indian Ocean, suggests that the source is located at 4.3 degN and 93.8 degE [Hanson et al., 2007]. This location coincides with along Middle Thrust, depicted by Sibuet et al. [2007], which is located in the middle outer arc-high. The estimate is considered precise but it is possible that the source location may be a few tens of kilometers at most trenchward of this position. The source size was much smaller than 30 km in length[Hanson et al.,2007]. All the studies above provide critical constraints on the location and mechanism of anomalous tsunami generation offshore northwest Sumatra. Taking these constraints into account, we can construct a new model to explain the unusual tsunami generation off northwest Sumatra. We thus propose the fifth model that the 2004 earthquake ruptured updip along the megathrust (plate interface) near the deformation front, but branched onto one of the outer-arc high splay faults: either the Middle Thrust or possibly the Lower Thrust of Sibuet et al.[2007].

Hirata, K.; Hanson, J. A.; Geist, E. L.; Seno, T.; Soh, W.; Fujiwara, T.; Muller, C.; Machiyama, H.; Araki, E.; Arai, K.; Watanabe, K.; Seeber, L.; Djajadihardia, Y. S.; Burhanuddin, S.; Kemal, B. M.; Hananto, N. D.; Kurnio, H.; Anantasena, Y.; Suyehiro, K.

2008-12-01

135

Numerical simulation of a tsunami event during the 1996 volcanic eruption in Karymskoye lake, Kamchatka, Russia  

Directory of Open Access Journals (Sweden)

Full Text Available Karymskoye caldera lake is a nearly circular body of water with a diameter of approximately 4 km and a depth of up to 60 m. The sublacustrine, Surtseyan-type eruption in the lake on 2–3 January 1996 included a series of underwater explosions. A field survey conducted the following summer showed signs of tsunami wave runup around the entire coastline of the lake, with a maximum of 29 m runup at the north shore near the source of the eruption, and 2–5 m runup at locations on the east and south shore far away from the source.

The tsunami has been simulated using the numerical long wave model COULWAVE, with input from reconstructed realistic pre-eruption bathymetry. The tsunami source was chosen as suggested by Le Mehaute (1971 and Mirchina and Pelinovsky (1988. The initial wave was prescribed by a parabolic shape depression with a radius of R=200 m, and a height of 23 m at the rim of the parabola. Simulations were conducted to show principle directions for wave propagation, wave speed and arrival time for the leading wave group at the shore, and the distribution of wave height throughout the lake. Estimated result for wave runup are of the same order of magnitude as field measurements, except near the source of the eruption and at a few locations where analysis show significant wave breaking.

T. Torsvik

2010-11-01

136

Hard probes and the event generator EPOS  

CERN Document Server

After a short presentation of the event generator EPOS, we discuss the production of heavy quarks and prompt photons which has been recently implemented. Whereas we have satisfying results for the charm, work on photons is still in progress.

Guiot, Benjamin

2014-01-01

137

Introduction to parton-shower event generators  

CERN Document Server

This lecture discusses the physics implemented by Monte Carlo event generators for hadron colliders. It details the construction of parton showers and the matching of parton showers to fixed-order calculations at higher orders in perturbative QCD. It also discusses approaches to merge calculations for a varying number of jets, the interface to the underlying event and hadronization.

Höche, Stefan

2014-01-01

138

Zero Magnitude Effect for the Productivity of Triggered Tsunami Sources  

Science.gov (United States)

The Epidemic Type Aftershock Sequence (ETAS) model is applied to tsunami events to explain previously observed temporal clustering of tsunami sources. Tsunami events are defined by National Geophysical Data Center (NGDC) tsunami database. For the ETAS analysis, the earthquake magnitude associated with each tsunami event in the NGDC database is replaced by the primary magnitude listed in the Centennial catalog up until 1976 and in the Global CMT catalog from 1976 through 2010. Tsunamis with a submarine landslide or volcanic component are included if they are accompanied by an earthquake, which is most often the case. Tsunami size is used as a mark for determining a tsunami-generating event, according to a minimum completeness level. The tsunami catalog is estimated to be complete for tsunami sizes greater than 1 m since 1900 and greater than 0.1 m since 1960. Of the five parameters in the temporal ETAS model (Ogata, 1988), the parameter that scales the magnitude dependence in the productivity of triggered events is the one that is most different from ETAS parameters derived from similar earthquake catalogs. Maximum likelihood estimates of this magnitude effect parameter is essentially zero, within 95% confidence, for both the 0.1 m and 1.0 m tsunami completeness levels. To explain this result, parameter estimates are determined for the Global CMT catalog under three tsunamigenic conditions: (1) M?7 and focal depth ?50 km, (2) submarine location, and (3) dominant component of dip slip. Successive subcatalogs are formed from the Global CMT catalog according to each of these conditions. The high magnitude threshold for tsunamigenesis alone (subcatalog 1) does not explain the zero magnitude effect. The zero magnitude effect also does not appear to be caused the smaller number of tsunamigenic events analyzed in comparison to earthquake catalogs with a similar magnitude threshold. ETAS parameter estimates from the subcatalog (3) with all three tsunamigenic conditions applied is consistent with ETAS parameters estimated from the tsunami catalog, suggesting that the dip-slip condition is important in explaining the zero magnitude effect. The consistency between ETAS parameters from the tsunami catalog and earthquake catalog with tsunamigenic conditions applied indicates that the ETAS model can be used as a framework for understanding the temporal occurrence of tsunami sources.

Geist, E. L.

2013-12-01

139

ALGERIA’S VULNERABILITY TO TSUNAMIS FROM NEAR-FIELD SEISMIC SOURCES  

Directory of Open Access Journals (Sweden)

Full Text Available Evaluation of the effects of tsunami damage relative to earthquake damage may help to identify critical coastal zone structures and exposed populations for near field tsunami risk. In this work, we propose to define the ratio between tsunami intensity and earthquake intensity as a measure of near field tsunami vulnerability for coastal communities. This parameter is estimated for 13 tsunami events reported in North Algeria from the 14th century to present. Although the results show that there are no tsunamis that are unusually large for the size of the earthquake that generated them, coastal communities remain at risk from these periodic hazards.We also use tsunami modelling and published information to estimate maximum inundation in Northern Algeria. Then, we generate a flooding map, which reveals the communities, buildings and infrastructure that are exposed to the tsunami hazard. This map shows that the majority of the people in Algiers and Oran live above 5 meters in elevation, and are hence not exposed to the hazard. Despite this, the coastline remains vulnerable to tsunami as earthquakes can damage poorly constructed buildings and other infrastructure, weakening it prior to the arrival of the tsunami. To increase resilience in the coastal zone, tsunami and earthquake awareness, education and preparedness must become a priority in the context of regional early warning programs.

ALGERIA’S VULNERABILITY TO TSUNAMIS FROM NEAR-FIELD SEISMIC SOURCES

2012-01-01

140

Optical dating of clastic deposits generated by an extreme marine coastal flood: The 1755 tsunami deposits in the Algarve (Portugal)  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Identification of past tsunamis is important for risk assessment and management of coastal areas. Obtaining accurate and precise ages of sediments originating from such extreme marine coastal floods is crucial for a reliable estimation of the recurrence interval of these often devastating events. We present here the results of quartz optical dating and 14C dating of two sites (Boca do Rio and Martinhal) on the Algarve coast (southern Portugal). These sites contain deposits of the ...

Cunha, P.

2010-01-01

 
 
 
 
141

Improving Tsunami Resilience in Europe - ASTARTE  

Science.gov (United States)

The North East Atlantic, Mediterranean and Adjacent Seas (called NEAM by IOC-UNESCO) is known to be exposed to tsunamis and, like other regions of the world, faces increasing levels of risk due to i) the continuous development of coastal areas with critical infrastructures and accumulated values, and ii) the year-round presence of millions of tourists. In recent years, European researchers have greatly advanced knowledge of tsunami hazards and implementation of operational infrastructures, such as the creation of a regional system of candidate tsunami watch providers (CTWP) and national tsunami warning centers (NTWC). However, significant gaps remain and intensified efforts are needed. The ASTARTE (Assessment STrategy And Risk for Tsunami in Europe) is a three-year long EU-funded project, started in November 2013, that aims to develop a comprehensive strategy to mitigate tsunami impact in the NEAM region. To achieve this goal, an interdisciplinary consortium has been assembled. It includes all NEAM CTWPs and expert institutions across Europe and worldwide. ASTARTE will improve i) the basic knowledge on tsunami generation and recurrence with novel empirical data and new statistical analyses for assessing long-term recurrence and hazards of large events in sensitive areas within NEAM, ii) numerical techniques for tsunami simulation focusing on real-time codes, novel statistical emulation approaches, and experiments on damage analysis, and iii) methods for the assessment of hazard, vulnerability, and risk. ASTARTE will also provide i) guidelines for tsunami Eurocodes, ii) better forecasting and warning tools for CTWPs and NTWCs, and iii) guidelines for decision makers to increase the sustainability and resilience of coastal communities. In summary, ASTARTE will develop basic scientific and technical elements allowing for a significant enhancement of the Tsunami Warning System in the NEAM region in terms of monitoring, early warning,forecast, and resilience, with specific implementation in 9 tsunami test sites. Overall, this will lead to the goal of the European/NEAM Horizon 2020 strategy: to foster tsunami resilient communities. www.astarte-project.eu This work is funded by project ASTARTE - Assessment, STrategy And Risk Reduction for Tsunamis in Europe. Grant 603839, 7th FP (ENV.2013.6.4-3 ENV.2013.6.4-3).

Baptista, Maria Ana; Yalciner, Ahmet; Canals, Miquel; Behrens, Joern; Fuhrman, David; Gonzalez, Mauricio; Harbitz, Carl; Kanoglu, Utku; Karanci, Nurai; Lavigne, Franck; Lorito, Stefano; Meghraoui, Mustafa; Melis, Nikolaos S.; Necmioglu, Ocal; Papadopoulos, Gerassimos A.; Rudloff, Alexander; Schindele, François; Terrinha, Pedro; Tinti, Stefano

2014-05-01

142

Tsunami generated by a granular collapse down a rough inclined plane  

Science.gov (United States)

In this letter, we experimentally investigate the collapse of initially dry granular media into water and the subsequent impulse waves. We systematically characterize the influence of the slope angle and the granular material on the initial amplitude of the generated leading wave and the evolution of its amplitude during the propagation. The experiments show that whereas the evolution of the leading wave during the propagation is well predicted by a solution of the linearized Korteweg-de Vries equation, the generation of the wave is more complicated to describe. Our results suggest that the internal properties of the granular media and the interplay with the surrounding fluid are important parameters for the generation of waves at low velocity impacts. Moreover, the amplitude of the leading wave reaches a maximum value at large slope angle. The runout distance of the collapse is also shown to be smaller in the presence of water than under totally dry conditions. This study provides a first insight into tsunamis generated by subaerial landslides at low Froude number.

Viroulet, S.; Sauret, A.; Kimmoun, O.

2014-02-01

143

The 2010 Mw 7.8 Mentawai earthquake: Very shallow source of a rare tsunami earthquake determined from tsunami field survey and near-field GPS data  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The M w 7.8 October 2010 Mentawai, Indonesia, earthquake was a >tsunami earthquake,> a rare type of earthquake that generates a tsunami much larger than expected based on the seismic magnitude. It produced a locally devastating tsunami, with runup commonly in excess of 6m. We examine this event using a combination of high-rate GPS data, from instruments located on the nearby islands, and a tsunami field survey. The GPS displacement time series are deficient in high-frequency energy, and show ...

Hill, Emma M.; Elosegui, Pedro

2012-01-01

144

Model Results For The 23 June, 2001 Peruvian Tsunami  

Science.gov (United States)

Tsunami generated by the June 23, 2001 Peruvian earthquake devastated Peru- vian coast near the epicenter and was recorded throughout Pacific by coastal tide-gages. This widespread impact motivated modeling efforts to produce re- alistic tsunami simulation of this event. Preliminary results were produced by the TIME center using two resident numerical models, TUNAMI-2 and MOST. Both models were used to produce preliminary simulation shortly after the earthquake, and first results were posted on the Internet a day after the event (http://www.pmel.noaa.gov/tsunami/peru_pmel.html). These numerical results aimed to quantify the magnitude of the tsunami and, to certain extend, to guide the post- tsunami survey. The first simulations have been revised using new data about the seis- mic source and the results of the post-tsunami survey by the International Tsunami Survey Team (ITST). We use the ITST measurements in heavily damaged Camana area to constrain our inundation model. Measured water-level data along the topo- graphic transects is used to constrain the inundation model. Preliminary numerical analysis of tsunami inundation will be presented.

Titov, V.; Borrero, J.; Koshimura, S.; Ortiz, M.

145

Preliminary Simulation Results of the 23 June, 2001 Peruvian Tsunami  

Science.gov (United States)

The tsunami generated by the June 23, 2001 Peruvian earthquake devastated a 50--km section of coast near the earthquake epicenter and was recorded on tide-gages throughout the Pacific. The coastal town of Camana sustained the most damage with tsunami waves penetrating up to 1--km inland and runup exceeding 5--m. The extreme local effects and widespread impact motivated modeling efforts to produce a realistic tsunami simulation of this event. Preliminary results were produced by the TIME center using two resident numerical models, TUNAMI--2 and MOST. Both models were used to produce preliminary simulations shortly after the earthquake, and first results were posted on the Internet a day after the event (http://www.pmel.noaa.gov/tsunami/peru_pmel.html). These numerical results aimed to quantify the magnitude of the tsunami and, to certain extent, to guide the post-tsunami survey. The first simulations have been revised using new data about the seismic source and the results of the post-tsunami survey. Measured inundation distances, flow depths, and runup along topographic transects are used to constrain the inundation model. Preliminary numerical analysis of tsunami inundation will be presented.

Titov, V. V.; Koshimura, S.; Ortiz, M.; Borrero, J.

2001-12-01

146

A Probabilistic Tsunami Hazard Assessment for Western Australia  

Science.gov (United States)

The occurrence of the Indian Ocean Tsunami on 26 December, 2004 has raised concern about the difficulty in determining appropriate tsunami mitigation measures in Australia, due to the lack of information on the tsunami threat. A first step in the development of such measures is a tsunami hazard assessment, which gives an indication of which areas of coastline are most likely to experience tsunamis, and how likely such events are. Here we present the results of a probabilistic tsunami hazard assessment for Western Australia (WA). Compared to other parts of Australia, the WA coastline experiences a relatively high frequency of tsunami occurrence. This hazard is due to earthquakes along the Sunda Arc, south of Indonesia. Our work shows that large earthquakes offshore of Java and Sumba are likely to be a greater threat to WA than those offshore of Sumatra or elsewhere in Indonesia. A magnitude 9 earthquake offshore of the Indonesian islands of Java or Sumba has the potential to significantly impact a large part of the West Australian coastline. The level of hazard varies along the coast, but is highest along the coast from Carnarvon to Dampier. Tsunamis generated by other sources (e.g., large intra-plate events, volcanoes, landslides and asteroids) were not considered in this study.

Burbidge, David; Cummins, Phil R.; Mleczko, Richard; Thio, Hong Kie

2008-12-01

147

Boulder Deposits on the Southern Spanish Atlantic Coast: Possible Evidence for the 1755 AD Lisbon Tsunami?  

Directory of Open Access Journals (Sweden)

Full Text Available Field evidence of visible tsunami impacts in Europe is scarce. This research focused on an analysis of large littoral debris and accompanying geomorphic features and their rela- tionship to a tsunami event at Cabo de Trafalgar, located on the southern Spanish Atlantic coast. Relative dating of weathering features as well as minor bioconstructive forms in the littoral zone suggest the Lisbon tsunami of 1755 AD as the event responsible for the large deposits described. This tsunami had run up heights of more than 19 m and was generated at the Gorringe Bank, located 500 km west off the Cape. Tsunami deposits at Cabo de Tra- falgar are the first boulder deposits identified on the southern Spanish Atlantic coast and are located approximately 250 km southeast of the Algarve coast (Portugal, where other geo- morphic evidence for the Lisbon tsunami has been reported.

Dieter Kelletat

2005-01-01

148

THE FRENCH TSUNAMI WARNING CENTER FOR THE MEDITERRANEAN AND NORTHEAST ATLANTIC: CENALT  

Directory of Open Access Journals (Sweden)

Full Text Available CENALT (CENtre d’ALerte aux Tsunamis is responsible for the French National Tsunami Warning Centre (NTWC. The CENALT is established in the framework of the Unesco/IOC/ICG/NEAMTWS. Its objective is to transmit a warning message in less than fifteen minutes for any events that could trigger a tsunami in the Western Mediterranean Sea and the North- Eastern Atlantic Ocean. The data collected from French installations and from institutions of European and North African countries is processed with software that permits early epicenter location of seismic events and measurements of expected tsunami impacts on the shore. On-duty analysts revise interactively all the generated information and use references of historical tsunami and earthquake databases - as well as computed tsunami scenarios – in order to disseminate the more comprehensive message possible.

H. Hébert

2013-01-01

149

On the moroccan tsunami catalogue  

Directory of Open Access Journals (Sweden)

Full Text Available A primary tool for regional tsunami hazard assessment is a reliable historical and instrumental catalogue of events. Morocco by its geographical situation, with two marine sides, stretching along the Atlantic coast to the west and along the Mediterranean coast to the north, is the country of Western Africa most exposed to the risk of tsunamis. Previous information on tsunami events affecting Morocco are included in the Iberian and/or the Mediterranean lists of tsunami events, as it is the case of the European GITEC Tsunami Catalogue, but there is a need to organize this information in a dataset and to assess the likelihood of claimed historical tsunamis in Morocco. Due to the fact that Moroccan sources are scarce, this compilation rely on historical documentation from neighbouring countries (Portugal and Spain and so the compatibility between the new tsunami catalogue presented here and those that correspond to the same source areas is also discussed.

F. Kaabouben

2009-07-01

150

Tsunami hazard in the Black Sea and the Azov Sea: a new tsunami catalogue  

Directory of Open Access Journals (Sweden)

Full Text Available Data on tsunamis occurring in the Black Sea and the Azov Sea from antiquity up to the present were updated, critically evaluated and compiled in the standard format developed since the 90's for the New European Tsunami Catalogue. Twenty nine events were examined but three of them, supposedly occurring in 557 AD, 815 AD and 1341 or 1343, were very likely falsely reported. Most of the remaining 26 events were generated in Crimea, offshore Bulgaria as well as offshore North Anatolia. For each of the 26 events examined, 22 events were classified as reliable ones receiving a score of 3 or 4 on a 4-grade reliability scale. Most of them were caused by earthquakes, such as the key event 544/545 of offshore Varna, but a few others were attributed either to aseismic earth slumps or to unknown causes. The tsunami intensity was estimated using the traditional 6-grade scale and the new 12-grade scale introduced by Papadopoulos and Imamura (2001. From 544/545 up to now, only two reliable events of high intensity K ? 7 have been reported, which very roughly indicates that the mean repeat time is ? 750 years. Five reliable tsunamis of moderate intensity 4 ? K < 7 have been observed from 1650 up to the present, which implies a recurrence of 72 years on the average. Although these calculations were based on a very small statistical sample of tsunami events, the repeat times found are consistent with the theoretical expectations from size-frequency relations. However, in the Black Sea there is no evidence of tsunamis of very high intensity (K ? 10 such as the AD 365, 1303 and 1956 ones associated with large earthquakes occurring along the Hellenic arc and trench, Greece, or the 1908 one in Messina strait, Italy. This observation, along with the relatively low tsunami frequency, indicates that the tsunami hazard in the Black Sea is low to moderate but not negligible. The tsunami hazard in the Azov Sea is very low because of the very low seismicity but also because of the shallow water prevailing there. In fact, only three possible tsunami events have been reported in the Azov Sea.

G. A. Papadopoulos

2011-03-01

151

In Brief: Tsunami preparedness progress  

Science.gov (United States)

Since the devastating Indian Ocean tsunami in 2004, the United States has made progress in several areas related to detecting and forecasting tsunamis, including the expansion of a sensor network and improvements to hazard and evacuation maps. However, many U.S. coastal communities “still face challenges in responding to a tsunami that arrives in less than an hour after the triggering event,” according to a U.S. National Research Council report released on 16 September. The report, Tsunami Warning and Preparedness: An Assessment of the U.S. Tsunami Program and the Nation's Preparedness Efforts, recommends that the U.S. National Oceanic and Atmospheric Administration and its National Tsunami Hazard Mitigation Program partners work to complete an initial assessment of tsunami risk, among other measures. The report also indicates research efforts to improve tsunami education, preparation, and detection. The report is available at http://www.nap.edu/catalog.php?record_id=12628.

Showstack, Randy

2010-09-01

152

Interdisciplinary approach for Tsunami Hazard Mitigation in Algeria (West Mediterranean)  

Science.gov (United States)

Numerous tsunamis occurred in the West Mediterranean with magnitudes ranging from m=-1 to m=2 (Imamura-Iida scale). In Algeria, tsunamis are reported from the 14th century to 2003. Northern Algeria is located at the border between the African and the Eurasian plate. Destructive earthquakes with magnitude greater than 6.7 occurred 3 times in the last century. The North Algeria western region is characterized by the Murdjadjo anticline. A destructive earthquake hit Oran city on October 1790 (Intensity: X, West of Algeria). A tsunami was triggered in the Alboran sea. The Spanish and North Africa coasts were flooded. Run-up’s of 2 meters in height are reported in historical documents (Lopez Marinas and Salord, 1990). Here, the 1790 Alboran tsunami is studied from a modelling approach. The tsunami source is determined from the Okada equations and the tsunami propagation is estimated from the SWAN code (Mader, 2004). Results show that active thrust faulting related to the Murdjadjo structure is responsible for the tsunami. In the central part of Algeria, the Algiers city (capital of Algeria) was the location of destructive earthquakes (Intensity: X) that were followed by tsunamis in 1365 and in 1773. Flooding and run-up’s of 2 meters in height are reported in historical documents for the 1365 event. The central part of Algeria is the site of the Sahel anticline. A tsunami modelling is also performed considering the Sahel fault system as a potential tsunami source. Results show that it takes less than 15 minutes for the tsunami waves to reach the Spanish coast. Run-up’s are estimated lower than 2 meters in height. Discrepancies are attributed to the resolution of the bathymetry and the limits of the modelling. In the eastern region, historical reports also reveal run-up’s up to 5 meters in height after a tsunami triggered by a destructive earthquake in 1856 in Jijel city (intensity: VIII). From tsunami catalogs, seismic and tsunami data are plotted using a tsunami vulnerability parameter. The vulnerability index is estimated from the tsunami intensity and the seismic intensity using the Papadopoulos and the EMS scale. Results show that in Algeria, tsunami damages are minor relative to seismic damages. Since the 2004 Sumatra-Andaman tsunami, intergovernmental coordinated groups are working on an Indian and a Mediterranean tsunami alert system. To reduce vulnerability and increase resilience, it is very important to implement an efficiency warning system and a communication policy for fast urbanized coastal cities. In that context, lessons from the pacific case study are of major interest. Chile is marked by a very high seismic and tsunami hazard. The Iquique area is a threaten zone for a potential earthquake of magnitude greater than 8 and a local tsunami that could generate run-up’s up to 20 meters in height. In addition to the Pacific Tsunami Warning centre based in Hawaii, the Chile has elaborated a local tsunami warning centre. The Chilean case study is presented in discussion to highlight some lessons that may serve as an example for fast urbanized coastal cities that have to face local tsunamis.

Amir, L. A.; Cisternas, A.; Vigneresse, J. D.

2009-12-01

153

Modeling the transport and accumulation floating debris generated by the 11 March 2011 Tohoku tsunami.  

Science.gov (United States)

A global ocean circulation model is coupled to a particle-tracking model to simulate the transport of floating debris washed into the North Pacific Ocean by the Tohoku tsunami. A release scenario for the tsunami debris is based on coastal population and measured tsunami runup. Archived 2011/2012 hindcast current data is used to model the transport of debris since the tsunami, while data from 2008 to 2012 is used to investigate the distribution of debris on timescales up to 4years. The vast amount of debris pushed into ocean likely represents thousands of years worth of 'normal' litter flux from Japan's urbanized coastline. This is important since a significant fraction of the debris will be comprised of plastics, some of which will degrade into tiny particles and be consumed by marine organisms, thereby allowing adsorbed organic pollutants to enter our food supply in quantities much higher than present. PMID:23219397

Lebreton, Laurent C-M; Borrero, Jose C

2013-01-15

154

Sediment resuspension, transportation and redeposition by tsunami: Example from the 2011 Tohoku-oki tsunami on Sendai and Sanriku shelves  

Science.gov (United States)

Although it is accepted that large tsunami waves impact the sea floor, the response of surface sediments to tsunami is not yet fully understood. Tsunami by the 2011 off the Pacific coast of Tohoku earthquake caused considerable damage to Northeast Japan. Large friction velocity at sea floor by the tsunami waves might agitate and resuspend the surface sediments especially on the shallow shelf. Therefore, formation of event deposits is expected at the wide area off Sanriku region. To understand the phenomena by the 2011 Tohoku-oki tsunami at sea floor, we conducted several surveys on Sendai and Sanriku shelf to forearc area. Large resuspension, transportation and redeposition of shelf mud and sand by the 2011 tsunami was recognized on mid-inner shelf in Sendai Bay. Resuspension of shelf mud made highly turbid water on the shelf. Settling of the suspended mud formed upward-fining graded (sometimes parallel-laminated) mud on the inner-mid shelf. Collapse of such high turbid water mass generated the turbidity currents, and formed turbidite on the outer shelf. Sediment resuspension and turbidity current generation also occurred on Sanriku shelf. Benthic foraminifera assemblage of the uppermost layer of event deposit occurred on the forearc basin floor contained shelf to upper slope species. This also indicates transportation of tsunami-induced gravity flow from shelf to forearc basin. Low gradient of shelf suggests that tsunami is most possible origin of sediment resuspension and turbidity current generation. Therefore, the tsunami-related sediment resuspension occurred at least on shelf to upper slope area, and turbidity currents generated with relation to such sediment resuspension is an important process to transport sediment from shelf to offshore basins.

Ikehara, K.; Usami, K.; Irino, T.

2013-12-01

155

A mathematical model for Tsunami generation using a conservative velocity-pressure hyperbolic system  

CERN Document Server

By using the Hugoniot curve in detonics as a Riemann invariant of a velocity-pressure model, we get a conservative hyperbolic system similar to the Euler equations. The only differences are the larger value of the adiabatic constant (= 8.678 instead of 1.4 for gas dynamics) and the mass density replaced by a strain density depending on the pressure. The model is not homogeneous since it involves a gravity and a friction term. After the seismic wave reaches up the bottom of the ocean, one gets a pressure wave propagating toward the surface, which is made of a frontal shock wave followed by a regular decreasing profile. Since this regular profile propagates faster than the frontal shock waves, the amplitude of the pressure wave is strongly reduced when reaching the surface. Only in the case of a strong earth tremor the residual pressure wave is still sufficient to generate a water elevation with a sufficient wavelengths enable to propagate as a SaintVenant water wave and to become a tsunami when reaching the sh...

Roux, Alain-Yves Le

2009-01-01

156

Post Fukushima tsunami simulations for Malaysian coasts  

Science.gov (United States)

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 for 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.

Koh, Hock Lye; Teh, Su Yean; Abas, Mohd Rosaidi Che

2014-10-01

157

Uncertainties of Tsunami Wave Height and Flow Velocity in the Tsunami Simulation due to Dynamic Fault Rupture Effects  

Science.gov (United States)

In 2011, the Great East Japan Earthquake generated the tsunami that exceeded our expectations and caused massive damage in the Northeast coast of Japan. One of the methods to avoid such unexpected event is to understand the uncertainties of tsunami wave height and flow velocity from an output of a tsunami simulation. There are two categories of fault parameters in the tsunami simulation: static parameters and dynamic parameters. Static parameters are such as dip, slip and strike angle. On the other hand, dynamic parameters are rupture velocity and rise time. So far, uncertainties of tsunami wave height due to static parameters has been studying by some previous studies. However, the effect of dynamic parameters are still unclear. In this study, we focused on the dynamic parameters and quantitatively assessed on how dynamic parameters in the tsunami simulation effect on the tsunami wave height and the flow velocity. Evaluation methods for uncertainties of the tsunami wave height and the flow velocity are as follows. Firstly, five unit faults were set. Tsunami simulations with rupture velocity were generated for 100 cases by conducting monte-carlo simulation based on probabilistic density function from gathered past seismic data. Rupture starting points were set to each unit fault (5 cases). Tsunami simulation were performed in a way that rupture spread radially,. Tsunami wave height and flow velocity data were collected at 58 fixed points and calculated the variability (log normal standard deviation) from median value of them. Throughout the statistical analysis of the above simulation cases, we found that these uncertainties due to dynamic fault rupture effects changed significantly depending on water depth and the location against the fault rupture. Uncertainties of tsunami wave height and flow velocity were almost zeroin the area located in strike direction of the fault rupture in any case of water depth. On the other hand, uncertainties of the tsunami wave height and the flow velocity were ?=0.15 at a maximum in the area that is parpendicular to strike direction of the fault rupture. As the water depth was deep, uncertainties became almost linearly large. From the sensitivity experiment by changing the dislocation of faults, uncertainties did not change significantly. In addition, we also conducted experimens that numbers of the sub faults were reduced to three faults. In that case, max uncertainties of the tsunami wave height and the flow velocity were almost the same value, but uncertainties changed locally compared with in the case of five small sub faults. The results in this study are supposed to be taken into account in the probabilistic tsunami hazard analysis (PTHA) as the aleatory uncertainty so that the PTHA is expected to be improved for the future.

Fukutani, Y.; Suppasri, A.; Imamura, F.

2013-12-01

158

Tsunami Hazard Assessment for Tsunamis of Tectonic Origin: a new Method Applied to South-West Italy  

Science.gov (United States)

Italy has been affected by large tsunamis in the past. From historical catalogues the occurrence rate of tsunamis in the Italian seas is about 15 events per century, which shows that tsunamis are very rare phenomena and that probabilistic techniques cannot be applied with confidence, especially if interest is not nation-wide but is focussed on regional coastal areas. Here a method is presented that derives tsunami potential from the assessment of the occurrence rate of tsunamigenic earthquakes, and that, therefore, makes use of seismic catalogues as the primary source of information. The method is restricted to tsunamis of seismic origin, and nothing can tell on tsunamis generated by volcanic activity and by mass movements. Improving a methodology originally used for a preliminary evaluation of tsunami hazard in Italy more than one decade ago (Tinti, 1991), this paper applies probabilistic seismic hazard techniques focussing on south-west Italy, namely on Calabria and Sicily, that are among the most active seismic regions in Italy. The analysis is based on the Italian seismic catalogue known as CPTI2, that was recently released (2004) and that is integrated with the INGV catalogue, spanning a time period longer than 2000 years. The main steps of the procedure are: 1) estimating the occurrence rate of tsunamigenic earthquakes; 2) assessing the initial disturbance of the sea, with the aid of appropriate relationships between the earthquake size and the ensuing tsunami size; 3) evaluating the expected maximum tsunami height on the coast, on the basis of the known propagation properties of tsunamis. As the result of the analysis, estimated return periods of earthquake-induced tsunamis capable of producing coastal wave heights exceeding a given threshold are computed and shown in the form of suitable maps.

Tinti, S.; Armigliato, A.; Tonini, R.; Maramai, A.; Graziani, L.

2004-12-01

159

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

Science.gov (United States)

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

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

2013-12-01

160

World Data Center / National Geophysical Data Center's Tsunami Data Archive  

Science.gov (United States)

The WDC for Solid Earth Geophysics (including tsunamis) is operated by NOAA's National Geophysical Data Center (NGDC). NGDC is one of three environmental data centers within the National Environmental Satellite, Data and Information Service (NESDIS). Operating both World and National Data Centers, WDC/NGDC is now providing the long-term archive, data management, and access to national and global tsunami data for research and mitigation of tsunami hazards. Archive responsibilities include the global historic tsunami event and runup database, the bottom pressure recorder data, and access to event-specific tide-gauge data, as well as other related hazards and bathymetric data and information. The WDC/NGDC Worldwide Tsunami Database includes more than 2,400 events since 2,000 BC and more than 7,200 locations where tsunamis were observed. Times of generating earthquakes, tsunami arrival times, travel times, first motion of the wave, and wave periods are included in the database. The WDC/NGDC Worldwide Significant Earthquake Database includes information for more than 6,600 destructive earthquakes from 2,000 B.C. to the present. In the 1980s, NOAA's Pacific Marine Environmental Laboratory (PMEL) developed deep ocean tsunameters for the early detection, measurement, and real-time reporting of tsunamis in the open ocean. The tsunameters were developed by PMEL's Project DART (Deep-ocean Assessment and Reporting of Tsunamis). A DART system consists of a seafloor bottom pressure recording (BPR) system capable of detecting tsunamis as small as 1 cm, and a moored surface buoy for real-time communications. An acoustic link is used to transmit data from the BPR on the seafloor to the surface buoy. The data are then relayed via a GOES satellite link to ground stations for immediate dissemination to NOAA's Tsunami Warning Centers and PMEL. These systems were deployed near regions with a history of tsunami generation, to ensure measurement of the waves as they propagate towards threatened U.S. coastal communities and to acquire data critical to real-time forecasts. Currently, there are eight BPRs located near Alaska, Hawaii, Chili, and in the equatorial Pacific. The WDC/NGDC is now providing access to bottom pressure recorder (BPR) data from 1986 to the present. The BPR database includes pressure and temperature data from the ocean floor. All of the WDC/NGDC tsunami and significant earthquake databases are stored in a relational database management system. These data are accessible over the Web as tables, reports, interactive maps, and custom CD-ROMs.

Dunbar, P. K.; Brantley, K.; Stroker, K.

2005-12-01

 
 
 
 
161

NOAA/WEST COAST AND ALASKA TSUNAMI WARNING CENTER PACIFIC OCEAN RESPONSE CRITERIA  

Directory of Open Access Journals (Sweden)

Full Text Available New West Coast/Alaska Tsunami Warning Center (WCATWC response criteria for earthquakes occurring in the Pacific basin are presented. Initial warning decisions are based on earthquake location, magnitude, depth, and - dependent on magnitude - either distance from source or pre- computed threat estimates generated from tsunami models. The new criteria will help limit the geographical extent of warnings and advisories to threatened regions, and complement the new operational tsunami product suite.Changes to the previous criteria include: adding hypocentral depth dependence, reducing geographical warning extent for the lower magnitude ranges, setting special criteria for areas not well-connected to the open ocean, basing warning extent on pre-computed threat levels versus tsunami travel time for very large events, including the new advisory product, using the advisory product for far-offshore events in the lower magnitude ranges, and specifying distances from the coast for on-shore events which may be tsunamigenic.This report sets a baseline for response criteria used by the WCATWC considering its processing and observational data capabilities as well as its organizational requirements. Criteria are set for tsunamis generated by earthquakes, which are by far the main cause of tsunami generation (either directly through sea floor displacement or indirectly by triggering of slumps. As further research and development provides better tsunami source definition, observational data streams, and improved analysis tools, the criteria will continue to adjust. Future lines of research and development capable of providing operational tsunami warning centers with better tools are discussed.

Garry Rogers

2008-01-01

162

NOAA/West Coast and Alaska Tsunami Warning Center Pacific Ocean response criteria  

Science.gov (United States)

New West Coast/Alaska Tsunami Warning Center (WCATWC) response criteria for earthquakes occurring in the Pacific basin are presented. Initial warning decisions are based on earthquake location, magnitude, depth, and - dependent on magnitude - either distance from source or precomputed threat estimates generated from tsunami models. The new criteria will help limit the geographical extent of warnings and advisories to threatened regions, and complement the new operational tsunami product suite. Changes to the previous criteria include: adding hypocentral depth dependence, reducing geographical warning extent for the lower magnitude ranges, setting special criteria for areas not well-connected to the open ocean, basing warning extent on pre-computed threat levels versus tsunami travel time for very large events, including the new advisory product, using the advisory product for far-offshore events in the lower magnitude ranges, and specifying distances from the coast for on-shore events which may be tsunamigenic. This report sets a baseline for response criteria used by the WCATWC considering its processing and observational data capabilities as well as its organizational requirements. Criteria are set for tsunamis generated by earthquakes, which are by far the main cause of tsunami generation (either directly through sea floor displacement or indirectly by triggering of slumps). As further research and development provides better tsunami source definition, observational data streams, and improved analysis tools, the criteria will continue to adjust. Future lines of research and development capable of providing operational tsunami warning centers with better tools are discussed.

Whitmore, P.; Benz, H.; Bolton, M.; Crawford, G.; Dengler, L.; Fryer, G.; Goltz, J.; Hansen, R.; Kryzanowski, K.; Malone, S.; Oppenheimer, D.; Petty, E.; Rogers, G.; Wilson, Jim

2008-01-01

163

Status of Monte-Carlo Event Generators  

Energy Technology Data Exchange (ETDEWEB)

Recent progress on general-purpose Monte-Carlo event generators is reviewed with emphasis on the simulation of hard QCD processes and subsequent parton cascades. Describing full final states of high-energy particle collisions in contemporary experiments is an intricate task. Hundreds of particles are typically produced, and the reactions involve both large and small momentum transfer. The high-dimensional phase space makes an exact solution of the problem impossible. Instead, one typically resorts to regarding events as factorized into different steps, ordered descending in the mass scales or invariant momentum transfers which are involved. In this picture, a hard interaction, described through fixed-order perturbation theory, is followed by multiple Bremsstrahlung emissions off initial- and final-state and, finally, by the hadronization process, which binds QCD partons into color-neutral hadrons. Each of these steps can be treated independently, which is the basic concept inherent to general-purpose event generators. Their development is nowadays often focused on an improved description of radiative corrections to hard processes through perturbative QCD. In this context, the concept of jets is introduced, which allows to relate sprays of hadronic particles in detectors to the partons in perturbation theory. In this talk, we briefly review recent progress on perturbative QCD in event generation. The main focus lies on the general-purpose Monte-Carlo programs HERWIG, PYTHIA and SHERPA, which will be the workhorses for LHC phenomenology. A detailed description of the physics models included in these generators can be found in [8]. We also discuss matrix-element generators, which provide the parton-level input for general-purpose Monte Carlo.

Hoeche, Stefan; /SLAC

2011-08-11

164

Update of the U.S. States and Territories National Tsunami Hazard Assessment: Historical Record and Sources for Waves  

Science.gov (United States)

The NOAA-National Geophysical Data Center (NGDC) and the U.S. Geological Survey (USGS) collaborated to conduct the first qualitative United States tsunami hazard assessment, published in 2008 by the National Tsunami Hazard Mitigation Program (NTHMP). Since that time, significant events such as the 2009 Samoa and 2011 Tohoku tsunamis have affected the U.S. and reinforced the importance of considering all of the evidence when conducting an assessment. In addition, there has been progress in tsunami research that reduces some of the earlier uncertainties. In 2011, the National Academies released their assessment of the U.S. Tsunami Program recommending that NOAA and its NTHMP partners, in collaboration with researchers in social and physical sciences, should complete an initial national assessment of tsunami risk and should institute a periodic assessment of the sources of tsunamis that threaten the United States. Therefore, the NTHMP is updating the national tsunami hazard assessment. Although the second assessment will not be a national probabilistic tsunami hazard assessment, areas where there is progress in this methodology will be presented. As a result, a national tsunami vulnerability and risk assessment is not possible at this time, but examples of ongoing work will be presented. This paper looks at the data sources in the first report, including an examination of the NGDC historical tsunami database that resulted in a qualitative assessment based on the distribution of runup heights and the frequency of tsunami runups. Although tsunami deaths are a measure of risk rather than hazard, the known tsunami deaths were compared with the qualitative assessments based on frequency and amplitude. The 2009 American Samoa tsunami resulted in a change for the U.S. Pacific island territories qualitative tsunami hazard assessment from 'Moderate' to 'High'. The NGDC tsunami database contains reported tsunamis and is therefore limited to written records existing for an area. Some of the uncertainty in the completeness of the written record has been reduced by investigating the history of tide gauges in the different regions. The first tsunami hazard assessment also used the USGS National Seismic Hazard Map (NSHM) databases to partially extend the time interval. These databases are primarily meant to assess earthquakes affecting U.S. possessions and do not include all possible seismogenic tsunami sources in the Pacific and Atlantic Basins. However, the databases make it possible to estimate the rate of occurrence of larger magnitude earthquakes that could generate a tsunami. The USGS NSHM databases are based on tectonic models, and paleoseismic and paleotsunami data. These databases are periodically updated with new research. Inclusion of updated information can reduce uncertainties in tsunami sources such as the Cascadia subduction zone and others.

Dunbar, P. K.; Goldfinger, C.

2013-12-01

165

Tsunamis in Cuba?; Tsunamis en Cuba?  

Energy Technology Data Exchange (ETDEWEB)

Cuba as neo tectonics structure in the southern of the North American plate had three tsunamis. One of them [local] occurred in the Central-Northern region [1931.10.01, Nortecubana fault], the other was a tele tsunami [1755.11.01, in the SW of the Iberian Peninsula] that hit the Bay of Santiago de Cuba, and the third took place at 1867.11.18, by the regional source of Virgin Islands, which produced waves in the Eastern Cuban region. This tsunami originated to the NE of Puerto Rico in 1918.10.11, with another earthquake of equal magnitude and at similar coordinates, produced a tsunami that did not affect Cuba. Information on the influence of regional tsunami in 1946.08.08 of the NE of the Dominican Republic [Matanzas] in Northwestern Cuba [beaches Guanabo-Baracoa] is contrary to expectations with the waves propagation. The local event of 1939.08.15 attributed to Central- Northern Cuba [Cayo Frances with M = 8.1] does not correspond at all with the maximum magnitude of earthquakes in this region and the potential of the Nortecubana fault. Tsunamis attributed to events such as 1766.06.11 and 1932.02.03 in the Santiago de Cuba Bay are not reflected in the original documents from experts and eyewitnesses. Tsunamis from Jamaica have not affected the coasts of Cuba, despite its proximity. There is no influence in Cuba of tsunamigenic sources of the southern and western parts of the Caribbean, or the Gulf of Mexico. Set out the doubts as to the influence of tsunamis from Haiti and Dominican Republic at Guantanamo Bay which is closer to and on the same latitude, and spatial orientation than the counterpart of Santiago de Cuba, that had impact. The number of fatalities by authors in the Caribbean is different and contradictory. (Author) 76 refs.

Cotilla Rodriguez, M. O.

2011-07-01

166

Development of tsunami early warning systems and future challenges  

Science.gov (United States)

Fostered by and embedded in the general development of information and communications technology (ICT), the evolution of tsunami warning systems (TWS) shows a significant development from seismic-centred to multi-sensor system architectures using additional sensors (e.g. tide gauges and buoys) for the detection of tsunami waves in the ocean. Currently, the beginning implementation of regional tsunami warning infrastructures indicates a new phase in the development of TWS. A new generation of TWS should not only be able to realise multi-sensor monitoring for tsunami detection. Moreover, these systems have to be capable to form a collaborative communication infrastructure of distributed tsunami warning systems in order to implement regional, ocean-wide monitoring and warning strategies. In the context of the development of the German Indonesian Tsunami Early Warning System (GITEWS) and in the EU-funded FP6 project Distant Early Warning System (DEWS), a service platform for both sensor integration and warning dissemination has been newly developed and demonstrated. In particular, standards of the Open Geospatial Consortium (OGC) and the Organization for the Advancement of Structured Information Standards (OASIS) have been successfully incorporated. In the FP7 project Collaborative, Complex and Critical Decision-Support in Evolving Crises (TRIDEC), new developments in ICT (e.g. complex event processing (CEP) and event-driven architecture (EDA)) are used to extend the existing platform to realise a component-based technology framework for building distributed tsunami warning systems.

Wächter, J.; Babeyko, A.; Fleischer, J.; Häner, R.; Hammitzsch, M.; Kloth, A.; Lendholt, M.

2012-06-01

167

Development of tsunami early warning systems and future challenges  

Directory of Open Access Journals (Sweden)

Full Text Available Fostered by and embedded in the general development of information and communications technology (ICT, the evolution of tsunami warning systems (TWS shows a significant development from seismic-centred to multi-sensor system architectures using additional sensors (e.g. tide gauges and buoys for the detection of tsunami waves in the ocean.

Currently, the beginning implementation of regional tsunami warning infrastructures indicates a new phase in the development of TWS. A new generation of TWS should not only be able to realise multi-sensor monitoring for tsunami detection. Moreover, these systems have to be capable to form a collaborative communication infrastructure of distributed tsunami warning systems in order to implement regional, ocean-wide monitoring and warning strategies.

In the context of the development of the German Indonesian Tsunami Early Warning System (GITEWS and in the EU-funded FP6 project Distant Early Warning System (DEWS, a service platform for both sensor integration and warning dissemination has been newly developed and demonstrated. In particular, standards of the Open Geospatial Consortium (OGC and the Organization for the Advancement of Structured Information Standards (OASIS have been successfully incorporated.

In the FP7 project Collaborative, Complex and Critical Decision-Support in Evolving Crises (TRIDEC, new developments in ICT (e.g. complex event processing (CEP and event-driven architecture (EDA are used to extend the existing platform to realise a component-based technology framework for building distributed tsunami warning systems.

J. Wächter

2012-06-01

168

NLO-QCD Event Generators in GRACE  

International Nuclear Information System (INIS)

Automatic Feynman-amplitude calculation system, GRACE, has been extended to treat next-to-leading order (NLO) QCD calculations. Matrix elements of loop diagrams as well as those of tree level ones can be generated using the GRACE system. A soft/collinear singularity is treated using a leading-log subtraction method. Higher order re-summation of the soft/collinear correction by the parton shower method is combined with the NLO matrix element without any double-counting in this method. An example of the event generator for W+ jet and di-photon processes are given for demonstrating a validity of this method. (author)

169

Numerical simulations of the 2011 Tohoku tsunami generation, propagation and coastal impact : comparison to field observations, with sensitivity analysis to co-seismic source parameters, model type and resolution  

Science.gov (United States)

The 2011 M9 Tohoku-Oki Earthquake ruptured the boundary separating the subducting Pacific Plate from the overriding Eurasian Plate, offshore from northern Honshu, Japan, generating large tsunami waves that caused numerous deaths and enormous destruction along a length of coast from 35-43 N Latitude. Various tsunami sources were developed for this event, based on inverting seismic or GPS data (e.g., by USGS, UCSB); others were developed based on inverting tsunami elevation measurements from deep-water DART buoys, offshore from Japan (e.g., NOAA). Here, we simulate both the far-field and near-field coastal impact of tsunami waves generated by these sources, and compare results to tide gage and runup measurements. Numerical simulations are performed using the fully nonlinear and dispersive Boussinesq wave model FUNWAVE-TVD, which is parallelized and available in Cartesian or spherical coordinates. We use a series of nested model grids, with varying resolution (finer than 500 m nearshore) and size, and assess effects on results of the latter and of model physics (such as with or without dispersion). While results based on seismic or GPS inversion sources (which often have very simple underlying fault models, such as Okada, 1985) can predict most of the key features of observed far-field and coastal measurements, they are not able to account for the largest tsunami runup and inundation (up to 25-40 m) observed north of 39.5 N Latitude. To this effect, new tsunami sources are being developed, based on inversions of onshore and offshore geodetic data, using 3D finite element models that simulate elastic dislocations along the plate boundary interface separating the stiff subducting Pacific Plate and relatively weak forearc and volcanic arc of the overriding Eurasian plate. Such sources produce significant shallow slip, several tens of meters, along the updip portion of the rupture near the trench, likely due to the simulated weak forearc materials and, once used in numerical models, may help explain the large runup and inundation to the north. Alternatively, the deeper slip of the homogeneous half-space "Okada" representation, used in seismic inversion models, underpredicts the amplitude of the tsunami and lags the wave in time.

Grilli, S. T.; Harris, J. C.; Tajalibakhsh, T.; Kirby, J. T.; Shi, F.; Masterlark, T.; Kyriakopoulos, C.

2011-12-01

170

Local Bathymetry and Shelf Resonance Effects Observed for the Near-field Tsunami Generated by the 2010, Mw 8.8, Maule Earthquake  

Science.gov (United States)

The Chilean coast has been hit by several far- and near-field tsunamis, for instance the last recent destructive tsunami devastating the Chilean shore was caused by the 2010 Mw 8.8, Maule earthquake. Several long-period waves were recorded away by DART buoys and local eyewitness and field surveys also confirm that incoming waves have hit the shore several hours after the leading wave arrival time. In addition, few published numerical modeling of the Maule near-field tsunami show trapping waves and amplification of the energy over the continental shelf. To better understand the origin of the tsunami wave trains and the continental shelf features as a potential responsible of resonance, we perform tsunami modeling by improving the earthquake source parameters modeling. We generate realistic 3D static displacement of the seafloor to be used as input for tsunami passive generation, propagation and runup estimates along the shore. We meshed the seismogenic contact zone between the Nazca and Sudamerica plates along the Maule region, through a 3D surface. The co-seismic slip distribution solution published for the Maule earthquake were used to model the runup, and trapped waves were observed on the numerical simulations. To further study the hypothesis of that a large magnitude earthquake may generate same kind of hydrodynamic effect, such as, successive tsunami wave trains, we modeled several hypothetical physical-based slip distributions for a Mw 8.8 earthquake rupture. At every subfault we used the Okada's point-source formula to compute the co-seismic static 3D displacement field. Preliminary results, show that a complex geometry of the slab have important effects on the vertical static displacements. We are currently evaluating the tsunami propagation for these hypothetical earthquakes, the study include understanding specific aspects related to local bathymetry, and hydrodynamic effects, among which, flow direction, directivity, reflection, diffraction, focusing/defocussing of water waves, and local shelf resonance.

Ruiz-Paredes, J. A.; Fuentes, M.; Riquelme, S.; Contreras Reyes, E.; Ruiz, S.; Maksymowicz, A.

2013-12-01

171

Probability-Based Design Criteria of the ASCE 7 Tsunami Loads and Effects Provisions (Invited)  

Science.gov (United States)

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.

Chock, G.

2013-12-01

172

Sources of Tsunami and Tsunamigenic Earthquakes in Subduction Zones  

Science.gov (United States)

We classified tsunamigenic earthquakes in subduction zones into three types earth quakes at the plate interface (typical interplate events), earthquakes at the outer rise, within the subducting slab or overlying crust (intraplate events), and "tsunami earthquakes" that generate considerably larger tsunamis than expected from seismic waves. The depth range of a typical interplate earthquake source is 10-40km, controlled by temperature and other geological parameters. The slip distribution varies both with depth and along-strike. Recent examples show very different temporal change of slip distribution in the Aleutians and the Japan trench. The tsunamigenic coseismic slip of the 1957 Aleutian earthquake was concentrated on an asperity located in the western half of an aftershock zone 1200km long. This asperity ruptured again in the 1986 Andreanof Islands and 1996 Delarof Islands earthquakes. By contrast, the source of the 1994 Sanriku-oki earthquake corresponds to the low slip region of the previous interplate event, the 1968 Tokachi-oki earthquake. Tsunamis from intraplate earthquakes within the subducting slab can be at least as large as those from interplate earthquakes; tsunami hazard assessments must include such events. Similarity in macroseismic data from two southern Kuril earthquakes illustrates difficulty in distinguishing interplate and slab events on the basis of historical data such as felt reports and tsunami heights. Most moment release of tsunami earthquakes occurs in a narrow region near the trench, and the concentrated slip is responsible for the large tsunami. Numerical modeling of the 1996 Peru earthquake confirms this model, which has been proposed for other tsunami earthquakes, including 1896 Sanriku, 1946 Aleutian and 1992 Nicaragua.

Satake, K.; Tanioka, Y.

173

Model-based tsunami warnings derived from observed impacts  

Directory of Open Access Journals (Sweden)

Full Text Available The Joint Australian Tsunami Warning Centre uses the T2 tsunami scenario database to provide forecast guidance for potential tsunami threats to the coastlines of mainland Australia and its external territories. This study describes a method for generating coastal tsunami warnings from model data obtained from the T2 scenario database. Consideration of observed coastal impacts for nine past events leads to retrospective or "ideal" warning schemes being designed. The 95th percentile values of maximum amplitude within designated coastal zones are examined and thresholds that produce the best match for the ideal schemes are selected. This empirical method is impact-based and allows the T2 scenarios to be used as a proxy for potential impacts on the coast in order to generate warnings for the Australian region.

S. C. R. Allen

2010-12-01

174

Firewaves: introducing a platform for modelling volcanic tsunamis  

Science.gov (United States)

When embracing all tsunamis generated by eruptive processes, rapid ground deformation and slope instability at volcanoes, "volcanic tsunamis" represent around 5 % of all tsunamis listed for the last four centuries (>130 events since 1600 AD). About 20-25 % of all fatalities directly attributable to volcanoes during the last 250 years have been caused by volcanic tsunamis (e.g. Krakatau 1883, Mayuyama 1792). Up to eight mechanisms are implied in the generation of volcanic tsunamis: underwater explosions, pyroclastic flows and lahars entering the water, earthquake preceding or during a volcanic eruption, and flank failure, collapse of coastal lava bench, caldera collapse, and shock wave produced by large explosion. It is unlikely that shock waves, lahars and collapses of lava bench can give birth to tsunamis with wave heights of more than 3 m. Pyroclastic flows, flank failures and caldera subsidence are the only source mechanisms likely to imply volumes larger than 1 km³. Volcanic tsunamis are characterised by short-period waves and greater dispersion compared to earthquake-generated tsunamis. With the exceptions of the 1888 Ritter Island and 1883 Krakatau tsunamis, 100 % of the victims of volcanic tsunamis in Southeast Asia were less than 20 km from the volcano. Travel time of the waves from the volcano to a distance of 20 km is typically less than 15 minutes (Paris et al. 2014). In this setting, priority are (1) to improve population's preparedness around highlighted volcanoes, (2) to monitor sea / lake around volcanoes, (3) and to build a database of numerical simulations based on different eruptive scenarios. The Firewaves platform, hosted at Magmas & Volcans laboratory in Clermont-Ferrand (FRance) is a numerical solution for modelling volcanic tsunamis of different sources. Tsunamis generated by volcanic mass flows (including pyroclastic flows, debris avalanches etc.) are simulated using VolcFlow code (Kelfoun et al. 2010), and underwater explosions and caldera subsidence using COMCOT (Liu et al. 1998). Three kinds of simulations are runned: (1) case-studies for calibrating the simulations (e.g. Stromboli 2002, Karymsky 1996, Mayuyama 1792), (2) comparisons of different scenarios for reconstructing past tsunamis (e.g. Kolumbo 1650), and (3) prospective scenarios from future eruptions at target volcanoes.

Paris, Raphaël; Ulvrova, Martina; Kelfoun, Karim; Giachetti, Thomas; Switzer, Adam

2014-05-01

175

New developments in event generator tuning techniques  

Energy Technology Data Exchange (ETDEWEB)

Data analyses in hadron collider physics depend on background simulations performed by Monte Carlo (MC) event generators. However, calculational limitations and non-perturbative effects in strong interactions require approximate models with adjustable parameters. In fact, we need to simultaneously adjust (''tune'') many phenomenological parameters in a high-dimensional parameter-space in order to make the MC generator predictions fit the data. I will present extensions and improvements of the systematic approach to MC tuning, called PROFESSOR (PROcedure For Estimating SyStematic errORs), whose key idea is to construct a fast analytic model of a MC generator response under parameter variations which can then be easily fitted to data. Among the improvements are a robust estimate of tuning uncertainties as well as a graphical user interface that allows for interactive exploration of the behaviour of observables under shifts in parameter space.

Schulz, Holger; Lacker, Heiko; Seggern, Jan Eike von [Humboldt University, Berlin (Germany); Buckley, Andy [University Edinburgh (United Kingdom); Hoeth, Hendrik [IPPP, Durham (United Kingdom)

2010-07-01

176

Integrated warning system for tsunami and storm surges in China  

International Nuclear Information System (INIS)

Tsunami and storm surges result in unusual oscillation of seal level, flooding the coastal zones and constitute the major marine disasters in China. Damage by storm surges occurs frequently. According to statistics there are 14 storm surge events exceeding 1 every year on the average. Six of them are typhoon surges and the other eight are extra-tropical surges. In general, in China, there is one severe disaster of storm surge every two years. Monitoring, forecasting and warning for storm surges, including the drop of water level, are the major part of the operational oceanographic services in China. Such a warning system has been set up and is operated by the State Oceanic Administration since 1974. The results of the historical study of tsunami in the last few years pointed out that the anomaly of sea level generated by tele-tsunamis originating in the Pacific Ocean Basin is less than 30 cm on the mainland coast, but local tsunami in the China Seas can be very dangerous. For example, more than 50,000 people were killed by a tsunami in Taiwan and in Taiwan Strait in 1781. It resulted in more deaths than any other tsunami in recorded history. However, the frequency of tsunami disaster is very low for the coast of China, averaging only one every 100 years. It is impossible to set up an independent tsunami warning system in China. It is more practical to set up an integrated warning system on tsunami and on storm surges consisting of: A sea level observing network with rg of: A sea level observing network with real time sea level data acquisition capability; A monitoring system of weather causing the storm surges and of seismic stations monitoring tsunamigenic earthquakes; A tidal prediction scheme for operational use; A forecasting scheme for storm surges and tsunami analysis; The means for warning dissemination. (author). 8 refs, 4 figs, 3 tabs

177

Dynamic generation of accident progression event trees  

International Nuclear Information System (INIS)

Currently, the development and analysis of accident progression event trees (APETs) are performed in a manner that is computationally time consuming, difficult to reproduce and also can be phenomenologically inconsistent. A software tool is presented for automated APET generation using the concept of dynamic event trees. The tool determines the branching times from a severe accident analysis code based on user specified criteria for branching. It assigns user specified probabilities to every branch, tracks the total branch probability, and truncates branches based on the given pruning/truncation rules to avoid an unmanageable number of scenarios. While the software tool could be applied to any systems analysis code, the MELCOR code is used for this illustration. A case study is presented involving station blackout with the loss of auxiliary feedwater system for a pressurized water reactor

178

Modelling of Tsunami Waves  

Directory of Open Access Journals (Sweden)

Full Text Available The nonlinear dispersive model based on the forced Korteweg-de Vries equation (fKdV is developed from the approximation of Boussinesq shallow water type model. This provides the possibility of observing, in particular, the process of tsunami generation by atmospheric disturbances. The fKdV is then solved numerically via an explicit finite difference method. From the simulations, the roles of nonlinearity, dispersion and forcing terms in the process of tsunami generation are shown explicitly.

Nazeeruddin Yaacob

2008-12-01

179

A review of tsunami simulation activities for NPPs safety  

International Nuclear Information System (INIS)

The tsunami generated on December 26, 2004 due to Sumatra earthquake of magnitude 9.3 resulted in inundation at the various coastal sites of India. The site selection and design of Indian nuclear power plants demand the evaluation of run up and the structural barriers for the coastal plants: Besides it is also desirable to evaluate the early warning system for tsunamigenic earthquakes. The tsunamis originate from submarine faults, underwater volcanic activities, sub-aerial landslides impinging on the sea and submarine landslides. In case of a submarine earthquake-induced tsunami the wave is generated in the fluid domain due to displacement of the seabed. There are three phases of tsunami: generation, propagation, and run-up. Reactor Safety Division (RSD) of Bhabha Atomic Research Centre (BARC), Trombay has initiated computational simulation for all the three phases of tsunami source generation, its propagation and finally run up evaluation for the protection of public life, property and various industrial infrastructures located on the coastal regions of India. These studies could be effectively utilized for design and implementation of early warning system for coastal region of the country apart from catering to the needs of Indian nuclear installations. This paper presents some results of tsunami waves based on finite difference numerical approaches with shallow water wave theory. The present paper evaluate the results of various simulation i.e. Single fault Sumatra model, four and five fault Sumatra Model, Nias insignificant tsunami and also some parametric studies results for tsunami waring system scenario generation. A study is carried for the tsunami due to Sumatra earthquake in 2004 with TUNAMI-N2 software. Bathymetry data available from the National Geophysical Data Center was used for this study. The single fault and detailed four and five fault data were used to calculate sea surface deformations which were subsequently used as initial conditions for Sumatra 2004 tsunami propagation simulation. The paper also presents a hypothetical study by assuming the earthquake rupture on northern fault only as compared to complete (northern and southern) rupture segment and the resulting tsunami propagation scenario. All of the studies provide the results in terms of wave heights and compare them with the reported simulation, satellite observation and field observed reported data. The paper includes the parametric studies on the possible fault line for Sumatra fault line for support for early tsunami warning. The various other events i.e Java, Nias, Makaran, Andaman etc are also discussed in the paper. (author)

180

Modeling Tsunami Sedimentation  

Science.gov (United States)

The inundation of a tsunami, whether generated from a submarine landslide or an underwater earthquake, often results in beach erosion, landward sediment transport, and deposition of a tsunami deposit. If the deposit is preserved, then it becomes a record of the tsunami, and may be useful in interpreting a region's tsunami hazard. In addition to the knowledge that a tsunami had previously inundated an area, is there more that can be learned from paleo-tsunami deposits? To address this question we are developing models of tsunami inundation and sediment transport and using them to relate sedimentological characteristics of the deposit, such as grain size and thickness, to hydrodynamic characteristics of the tsunami, such as maximum velocity and flow depth. Model results are tested and verified using field data from the 2004 Indian Ocean tsunami. Data on tsunami flow depth, inundation distance, nearshore bathymetry, topography, tsunami deposit thickness, and sediment samples for grain size analysis were collected along several cross shore transects in Sumatra. These data are compared to predictions of erosion and deposition from a high resolution tsunami inundation and sediment transport model constructed over a 4-km cross shore section of coast. The Delft3D model, which solves the non-linear shallow water equations and calculates sediment transport with van Rijn (1993), is implemented with a flooding algorithm proven accurate for dam-break scenarios with rapid flooding. Forced with an offshore water level boundary condition taken from an Indian Ocean propagation model, the high-resolution inundation model predicts tsunami shoaling at the coast, with the wave-form steepening, wavelength decreasing, and wave height increasing. Maximum flow at the shoreline is directed offshore during the drawdown phase and is enhanced by the draining of water off the coastal plain. This offshore flow erodes the beach, transporting a substantial volume of sediment to a depth of approximately 12 m (msl), precisely the location of an offshore bar observed in the bathymetric data. Onshore flow, reaching a maximum velocity of approximately 8 m/s, also erodes the beach and carries sand onto the coastal plain. The tsunami deposit on land varies in thickness, with thinner deposits on topographic highs and thicker deposits in topographic lows. Model results suggest that variations in thickness results from divergences and convergences in the sediment flux as the flow slows over the topographic lows and speeds up over the topographic highs. Model results also indicate that the deposit thickness is sensitive to sediment grain size. Since the grain size of the deposit is poly-modal, multiple grain sizes should be included in future simulations.

Gelfenbaum, G.; Jaffe, B.; Elias, E.; Moore, A.; Ruggiero, P.; Morton, R.

2006-12-01

 
 
 
 
181

Web-based Tsunami Early Warning System: a case study of the 2010 Kepulaunan Mentawai Earthquake and Tsunami  

Science.gov (United States)

This study analyzes the response of the Global Disasters Alerts and Coordination System (GDACS) in relation to a case study: the Kepulaunan Mentawai earthquake and related tsunami, which occurred on 25 October 2010. The GDACS, developed by the European Commission Joint Research Center, combines existing web-based disaster information management systems with the aim to alert the international community in case of major disasters. The tsunami simulation system is an integral part of the GDACS. In more detail, the study aims to assess the tsunami hazard on the Mentawai and Sumatra coasts: the tsunami heights and arrival times have been estimated employing three propagation models based on the long wave theory. The analysis was performed in three stages: (1) pre-calculated simulations by using the tsunami scenario database for that region, used by the GDACS system to estimate the alert level; (2) near-real-time simulated tsunami forecasts, automatically performed by the GDACS system whenever a new earthquake is detected by the seismological data providers; and (3) post-event tsunami calculations using GCMT (Global Centroid Moment Tensor) fault mechanism solutions proposed by US Geological Survey (USGS) for this event. The GDACS system estimates the alert level based on the first type of calculations and on that basis sends alert messages to its users; the second type of calculations is available within 30-40 min after the notification of the event but does not change the estimated alert level. The third type of calculations is performed to improve the initial estimations and to have a better understanding of the extent of the possible damage. The automatic alert level for the earthquake was given between Green and Orange Alert, which, in the logic of GDACS, means no need or moderate need of international humanitarian assistance; however, the earthquake generated 3 to 9 m tsunami run-up along southwestern coasts of the Pagai Islands where 431 people died. The post-event calculations indicated medium-high humanitarian impacts.

Ulutas, E.; Inan, A.; Annunziato, A.

2012-06-01

182

Event generation with SHERPA 1.1  

Energy Technology Data Exchange (ETDEWEB)

In this paper the current release of the Monte Carlo event generator Sherpa, version 1.1, is presented. Sherpa is a general-purpose tool for the simulation of particle collisions at high-energy colliders. It contains a very flexible tree-level matrix-element generator for the calculation of hard scattering processes within the Standard Model and various new physics models. The emission of additional QCD partons off the initial and final states is described through a parton-shower model. To consistently combine multi-parton matrix elements with the QCD parton cascades the approach of Catani, Krauss, Kuhn and Webber is employed. A simple model of multiple interactions is used to account for underlying events in hadron-hadron collisions. The fragmentation of partons into primary hadrons is described using a phenomenological cluster-hadronization model. A comprehensive library for simulating tau-lepton and hadron decays is provided. Where available form-factor models and matrix elements are used, allowing for the inclusion of spin correlations; effects of virtual and real QED corrections are included using the approach of Yennie, Frautschi and Suura.

Gleisberg, T.; Hoche, Stefan.; Krauss, F.; Schoenherr, M.; Schumann, S.; Siegert, F.; Winter, J.

2008-12-18

183

NOAA/WEST COAST AND ALASKA TSUNAMI WARNING CENTER ATLANTIC OCEAN RESPONSE CRITERIA  

Directory of Open Access Journals (Sweden)

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

Paul Whitmore

2009-01-01

184

Reconstruction of Tsunami Inland Propagation on December 26, 2004 in Banda Aceh, Indonesia, through Field Investigations  

Science.gov (United States)

This paper presents the results from an extensive field data collection effort following the December 26, 2004 earthquake and tsunami in Banda Aceh, Sumatra. The data were collected under the auspices of TSUNARISQUE, a joint French-Indonesian program dedicated to tsunami research and hazard mitigation, which has been active since before the 2004 event. In total, data from three months of field investigations are presented, which detail important aspects of the tsunami inundation dynamics in Banda Aceh. These include measurements of runup, tsunami wave heights, flow depths, flow directions, event chronology and building damage patterns. The result is a series of detailed inundation maps of the northern and western coasts of Sumatra including Banda Aceh and Lhok Nga. Among the more important findings, we obtained consistent accounts that approximately ten separate waves affected the region after the earthquake; this indicates a high-frequency component of the tsunami wave energy in the extreme near-field. The largest tsunami wave heights were on the order of 35 m with a maximum runup height of 51 m. This value is the highest runup value measured in human history for a seismically generated tsunami. In addition, our field investigations show a significant discontinuity in the tsunami wave heights and flow depths along a line approximately 3 km inland, which the authors interpret to be the location of the collapse of the main tsunami bore caused by sudden energy dissipation. The propagating bore looked like a breaking wave from the landward side although it has distinct characteristics. Patterns of building damage are related to the location of the propagating bore with overall less damage to buildings beyond the line where the bore collapsed. This data set was built to be of use to the tsunami community for the purposes of calibrating and improving existing tsunami inundation models, especially in the analysis of extreme near-field events.

Lavigne, Franck; Paris, Raphaël; Grancher, Delphine; Wassmer, Patrick; Brunstein, Daniel; Vautier, Franck; Leone, Frédéric; Flohic, François; de Coster, Benjamin; Gunawan, Taufik; Gomez, Christopher; Setiawan, Anggri; Cahyadi, Rino; Fachrizal

2009-02-01

185

Scientific Animations for Tsunami Hazard Mitigation: The Pacific Tsunami Warning Center's YouTube Channel  

Science.gov (United States)

Outreach and education save lives, and the Pacific Tsunami Warning Center (PTWC) has a new tool--a YouTube Channel--to advance its mission to protect lives and property from dangerous tsunamis. Such outreach and education is critical for coastal populations nearest an earthquake since they may not get an official warning before a tsunami reaches them and will need to know what to do when they feel strong shaking. Those who live far enough away to receive useful official warnings and react to them, however, can also benefit from PTWC's education and outreach efforts. They can better understand a tsunami warning message when they receive one, can better understand the danger facing them, and can better anticipate how events will unfold while the warning is in effect. The same holds true for emergency managers, who have the authority to evacuate the public they serve, and for the news media, critical partners in disseminating tsunami hazard information. PTWC's YouTube channel supplements its formal outreach and education efforts by making its computer animations available 24/7 to anyone with an Internet connection. Though the YouTube channel is only a month old (as of August 2013), it should rapidly develop a large global audience since similar videos on PTWC's Facebook page have reached over 70,000 viewers during organized media events, while PTWC's official web page has received tens of millions of hits during damaging tsunamis. These animations are not mere cartoons but use scientific data and calculations to render graphical depictions of real-world phenomena as accurately as possible. This practice holds true whether the animation is a simple comparison of historic earthquake magnitudes or a complex simulation cycling through thousands of high-resolution data grids to render tsunami waves propagating across an entire ocean basin. PTWC's animations fall into two broad categories. The first group illustrates concepts about seismology and how it is critical to tsunami warning operations, such as those about earthquake magnitudes, how earthquakes are located, where and how often earthquakes occur, and fault rupture length. The second group uses the PTWC-developed tsunami forecast model, RIFT (Wang et al., 2012), to show how various historic tsunamis propagated through the world's oceans. These animations illustrate important concepts about tsunami behavior such as their speed, how they bend around and bounce off of seafloor features, how their wave heights vary from place to place and in time, and how their behavior is strongly influenced by the type of earthquake that generated them. PTWC's YouTube channel also includes an animation that simulates both seismic and tsunami phenomena together as they occurred for the 2011 Japan tsunami including actual sea-level measurements and proper timing for tsunami alert status, thus serving as a video 'time line' for that event and showing the time scales involved in tsunami warning operations. Finally, PTWC's scientists can use their YouTube channel to communicate with their colleagues in the research community by supplementing their peer-reviewed papers with video 'figures' (e.g., Wang et al., 2012).

Becker, N. C.; Wang, D.; Shiro, B.; Ward, B.

2013-12-01

186

Tsunami inundation scenarios and tsunami vulnerability assessment for the town of Alexandria, Egypt  

Science.gov (United States)

Historical catalogues indicate that Alexandria was severely affected in the past by several tsunami events. The tsunami hazard in that area is mainly due to far-field tectonic sources. The two most famous earthquakes that generated tsunamis whose impact was experienced also by Alexandria and the surrounding area are the 365 AD and the 1303 earthquakes, whose sources are still a matter of debate but are frequently located in correspondence with the western and eastern sectors of the Hellenic Arc. Nowadays, Alexandria is the second biggest city in Egypt as regards population (3.9 million), it is a key economic area in northern Africa and it has a very important tourist activity. Hence the proper assessment of tsunami hazard-to-risk must be regarded as an important task, which was partially undertaken in the very recent past by projects such as TRANSFER (EU-FP6). It is also worth mentioning that the overall eastern Mediterranean is one of the areas chosen by the EU-FP7 Project TRIDEC to test a new generation Tsunami Early Warning Decision Support System. We assess the hazard by performing numerical simulations of tsunami impact in Alexandria through the worst-case scenario technique. We identify three main seismic sources: the western Hellenic Arc (reference event 365 AD, magnitude 8.3), the eastern Hellenic Arc (reference event 1303, magnitude 8.0) and the Cyprus arc (hypothetical scenario with magnitude 8.0, inferred from the tectonic setting and the historical seismic catalogues). All the simulations and the inundation maps are computed by means of the UBO-TSUFD code, developed and maintained by the Tsunami Research team of the University of Bologna, which solves the non-linear shallow-water equations allowing for the computation of run-up and inundation on nested grids. For each of the considered scenarios we compute all the relevant tsunami metrics, i.e. water elevation, current speed, flow depth and momentum flux. We find that the case that produces the most relevant flooding in Alexandria is the eastern Hellenic Arc scenario, with waves reaching heights up to 5 meters. We also prepare an aggregated field for each relevant physical parameter, by choosing for each parameter the highest value in each computational grid point. The aggregated fields are finally used for a preliminary tsunami vulnerability assessment based on a methodology developed by the EU-FP6 SCHEMA Project, based on the adoption of a suitable building damage matrix and on water inundation depth.

Tinti, S.; Pagnoni, G.; Armigliato, A.; Tonini, R.

2012-04-01

187

Sensitivity of tsunami wave profiles and inundation simulations to earthquake slip and fault geometry for the 2011 Tohoku earthquake  

Science.gov (United States)

In this study, we develop stochastic random-field slip models for the 2011 Tohoku earthquake and conduct a rigorous sensitivity analysis of tsunami hazards with respect to the uncertainty of earthquake slip and fault geometry. Synthetic earthquake slip distributions generated from the modified Mai-Beroza method captured key features of inversion-based source representations of the mega-thrust event, which were calibrated against rich geophysical observations of this event. Using original and synthesised earthquake source models (varied for strike, dip, and slip distributions), tsunami simulations were carried out and the resulting variability in tsunami hazard estimates was investigated. The results highlight significant sensitivity of the tsunami wave profiles and inundation heights to the coastal location and the slip characteristics, and indicate that earthquake slip characteristics are a major source of uncertainty in predicting tsunami risks due to future mega-thrust events.

Goda, Katsuichiro; Mai, Paul Martin; Yasuda, Tomohiro; Mori, Nobuhito

2014-12-01

188

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

Science.gov (United States)

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

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

2011-12-01

189

Modern Particle Physics Event Generation with WHIZARD  

CERN Document Server

We describe the multi-purpose Monte-Carlo event generator WHIZARD for the simulation of high-energy particle physics experiments. Besides the presentation of the general features of the program like SM physics, BSM physics, and QCD effects, special emphasis will be given to the support of the most accurate simulation of the collider environments at hadron colliders and especially at future linear lepton colliders. On the more technical side, the very recent code refactoring towards a completely object-oriented software package to improve maintainability, flexibility and code development will be discussed. Finally, we present ongoing work and future plans regarding higher-order corrections, more general model support including the setup to search for new physics in vector boson scattering at the LHC, as well as several lines of performance improvements.

Reuter, J; Nejad, B Chokoufe; Kilian, W; Ohl, T; Sekulla, M; Weiss, C

2014-01-01

190

Precision event generation for the LHC  

Energy Technology Data Exchange (ETDEWEB)

In order to maximize the discovery potential of the Large Hadron Collider, precise predictions are needed for a multitude of Standard Model reactions. Signals for new physics may be hidden in overwhelming backgrounds, which have to be controlled in order to find anomalies withstanding detailed scrutiny. Tremendous progress was made in recent years to improve the theoretical description of these backgrounds using next-to-leading order (NLO) QCD. This talk reviews some of the essential aspects of modern multi-jet NLO calculations and presents results in comparison to recent LHC data. The need for theoretical predictions at the particle level has spurred the development of so-called matching algorithms, which connect NLO parton-level results and parton showers as part of general-purpose Monte-Carlo event generators. The theoretical challenges of these methods for large jet multiplicity are discussed with particular emphasis on the correct treatment of subleading colour and soft gluon effects.

Hoeche, Stefan [SLAC National Accelerator Laboratory, Menlo Park (United States)

2012-07-01

191

Elegent—An elastic event generator  

Science.gov (United States)

Although elastic scattering of nucleons may look like a simple process, it presents a long-lasting challenge for theory. Due to missing hard energy scale, the perturbative QCD cannot be applied. Instead, many phenomenological/theoretical models have emerged. In this paper we present a unified implementation of some of the most prominent models in a C++ library, moreover extended to account for effects of the electromagnetic interaction. The library is complemented with a number of utilities. For instance, programs to sample many distributions of interest in four-momentum transfer squared, t, impact parameter, b, and collision energy ?{s}. These distributions at ISR, Spp¯S, RHIC, Tevatron and LHC energies are available for download from the project web site. Both in the form of ROOT files and PDF figures providing comparisons among the models. The package includes also a tool for Monte-Carlo generation of elastic scattering events, which can easily be embedded in any other program framework. Catalogue identifier: AERT_v1_0 Program summary URL:http://cpc.cs.qub.ac.uk/summaries/AERT_v1_0.html Program obtainable from: CPC Program Library, Queen’s University, Belfast, N. Ireland Licensing provisions: GNU General Public License, version 3 No. of lines in distributed program, including test data, etc.: 10551 No. of bytes in distributed program, including test data, etc.: 126316 Distribution format: tar.gz Programming language: C++. Computer: Any in principle, tested on x86-64 architecture. Operating system: Any in principle, tested on GNU/Linux. RAM: Strongly depends on the task, but typically below 20MB Classification: 11.6. External routines: ROOT, HepMC Nature of problem: Monte-Carlo simulation of elastic nucleon-nucleon collisions Solution method: Implementation of some of the most prominent phenomenological/theoretical models providing cumulative distribution function that is used for random event generation. Running time: Strongly depends on the task, but typically below 1 h.

Kašpar, J.

2014-03-01

192

Numerical simulation of the tsunami generated by the 2007 Noto Hanto Earthquake and implications for unusual tidal surges observed in Toyama Bay  

Science.gov (United States)

We conducted a numerical analysis of the tsunami generated by the 2007 Noto Hanto Earthquake ( M j = 6.9) that occurred on 25 March 2007 near the Noto Peninsula on the northwest coast of Honshu Island, Japan. Our numerical simulation reproduced well the behaviors of the tsunami as recorded at the Wajima tidal observatory and showed that the computed tsunami arrived in Toyama Bay more than 1 h after the earthquake. However, a crew of a small boat in the bay felt the shock and, despite calm weather conditions, their boat capsized just 3 min after the earthquake. Although abnormal tidal surges were recorded at several locations around Toyama Bay, the timing of these is inconsistent with the surges being a direct result of the tsunami generated at the source area of the earthquake. We used "backward wave propagation analysis" to estimate the likely source area of the abnormal tidal surges in the bay and carried out the a simulation of landslide-induced tsunami. Our conclusion is that these abnormal tidal surges were likely caused by a submarine landslide on the steep sea floor on the western side of Toyama Bay.

Abe, Ikuo; Goto, Kazuhisa; Imamura, Fumihiko; Shimizu, Katsuyoshi

2008-02-01

193

Modeling and Visualization of Tsunamis  

Science.gov (United States)

Modeling tsunami wave propagation is a very challenging numerical task, because it involves many facets: Such as the formation of various types of waves and the impingement of these waves on the coast. We will discuss the different levels of approximations made in numerical modeling of 2-D and 3-D tsunami waves and their relative difficulties. In this paper new attempts are proposed to evaluate the hazards of tsunami’s and visualization of large-scale numerical results generated from tsunami simulations. Specialized low-level computer language, based on a parallel computing environment, is also employed here for generating FORTRAN source code for finite elements. This code can then be run very efficiently in parallel on distributed computing systems. We will also discuss the need to study tsunami waves with modern software and visualization hardware.

Zhang, Huai; Shi, Yaolin; Yuen, David A.; Yan, Zhenzhen; Yuan, Xiaoru; Zhang, Chaofan

2008-04-01

194

Tsunami Hazard Awareness from past Experience and the Differing Vulnerability of Indigenous and Immigrant Coastal Populations  

Science.gov (United States)

The high mortality rates (10 percent to over 90 percent) amongst tourist and immigrant populations caught in the 2004 Indian Ocean tsunami contrast both with the lower mortality where local warnings were effective, and with historically low mortality rates in several major tsunamis in Papua New Guinea and the South West Pacific. These include early 20th Century events in which responses to the tsunamis were based upon oral traditions that existed amongst indigenous populations. Eyewitness accounts of one of these events, the 1930 Ninigo Islands tsunami in Papua New Guinea, indicate that people in coastal villages recognized warning signs such as initial drawdown of the sea, and evacuated inland before the tsunami struck with intensities comparable to the 2004 tsunami in Thailand. Maximum runups exceeded 15 meters on Karkar Island and were 5 to 10 meters around much of the Bismarck Sea. Although many villages were severely damaged, only 12 people were killed. The mortality rate was less than 1 percent and perhaps as little as 0.1 percent of the population in the inundation zones. Interviews with populations who have lived on coasts for many generations indicate a high level of tsunami awareness including oral traditions of earlier historical events and traditional beliefs regarding tsunamis and earthquakes. The generally low mortality rates in these events indicate that self - warning and voluntary evacuation constitutes a highly effective tsunami mitigation measure amongst indigenous peoples. The challenge today is to develop similar behaviors amongst immigrant and transient populations in tsunami prone areas through Education for Self - Warning and Voluntary Evacuation (ESWAVE): the efforts of volcanologists after the 1985 Armero lahar disaster provide pointers as to how this can be done.

Day, S. J.

2007-12-01

195

Tsunamis of the northeast Indian Ocean with a particular focus on the Bay of Bengal region—A synthesis and review  

Science.gov (United States)

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.

Alam, Edris; Dominey-Howes, Dale; Chagué-Goff, Catherine; Goff, James

2012-08-01

196

Tsunami Hazard Assessment along the Coast of Oman from Near- and Far-field Tectonic Sources  

Science.gov (United States)

Coastal areas of Oman are exposed to tsunami threat associated with earthquakes generated in two major subduction zones, namely Makran and Sumatra. Both zones were responsible of triggering tsunamis that reached/impacted Oman coast. The Mw8.1 earthquake event of 1945, occurred in Makran zone, has caused a tsunami that was reported to affect the coast of Oman. The Mw9.2 Indian Ocean event of 2004 triggered a tsunami that was recorded in various tide-gauges stations of Oman with wave amplitude reaching ~1.7m in the port of Salalah. This work aims to assess tsunami hazard along the Oman coast considering both deterministic and probabilistic approaches. Deterministic approach uses particular source scenarios (most credible and/or worst case) from Makran and Sumatra subduction zones and computes the tsunami coastal impact through numerical modeling of expected waveforms, maximum wave heights distribution, and site-specific inundations. While, probabilistic approach includes the contribution of small and large sources and employs the probabilistic seismic hazard assessment together with the numerical modeling to evaluate the likelihood that a certain level of tsunami threat is exceeded at a certain location of Oman coast within a certain period of time. We present deterministic results in terms of regional scale distribution of maximum wave heights, tsunami waveforms computation, and inundation maps for a selected coastal area. For probabilistic assessment, we derive 250- and 500-years probability hazard exceedance maps and hazard curves for the Oman coast. The hazard maps consist of computing the likelihood that tsunami waves exceed a specific amplitude for the entire coast of Oman, and the hazard curves describe the variation of cumulative probabilities as function of wave amplitudes at some critical coastal points. Finally, we discuss the usefulness of obtained results for tsunami mitigation in Oman. Keywords: Tsunami, Oman, Deterministic approach, Probabilistic approach.

El-Hussain, Issa; Baptista, Maria; Omira, Rachid; Al-Rawas, Ghazi; Deif, Ahmed; Al-Habsi, Zaid; Al-Jabri, Khalifa

2014-05-01

197

Possible sources of the tsunami observed in the northwestern Indian Ocean following the 2013 September 24 Mw 7.7 Pakistan inland earthquake  

Science.gov (United States)

We report and analyse the tsunami recorded in the northwestern Indian Ocean at the Makran region following the Mw 7.7 Pakistan inland strike-slip earthquake on 2013 September 24. We analyse eleven tide gauge records as well as one DART record of this tsunami and perform numerical modelling of the tsunami that would be triggered by a range of possible sources. The tsunami registered a maximum wave height of 109 cm at the Qurayat tide gauge station (Oman). The dominant period of the tsunami was around 12 min, although wavelet analysis showed that parts of the tsunami energy were partitioned into a slightly wider period range of 7 and 16 min. Tsunami backward ray tracing showed that the tsunami source was possibly located offshore Jiwani (Pakistan) and that the tsunami was most likely triggered by the main shock. The aftershocks are distributed in the inland region and the coseismic vertical and horizontal displacements are also limited inland implying that the tsunami was generated by secondary sources triggered by the earthquake. Different possible tsunami sources including a mud volcano at the location of the newly generated island, and a mud volcano or diapir at offshore deep water were examined through numerical modelling and all failed to reproduce the observed waveforms. Numerical modelling showed that a submarine slump with a source dimension of about 10-15 km and a thickness of about 100 m located at 61.49°E and 24.62°N, that is, about 60-70 km off the Jiwani coast (Pakistan), seems capable of reasonably reproducing the wave amplitudes and periods of the observed tsunami waveforms. This event was the second instrumentally recorded tsunami in the region, after the Makran tsunami of 1945 November, and provides evidence for a hazard from landslide/slump-generated waves following seismic activity in the area.

Heidarzadeh, Mohammad; Satake, Kenji

2014-11-01

198

Quantifying Tsunami Impact on Structures  

Science.gov (United States)

Tsunami impact is usually assessed through inundation simulations and maps which provide estimates of coastal flooding zones based on "credible worst case" scenarios. Earlier maps relied on one-dimensional computations, but two-dimensional computations are now employed routinely. In some cases, the maps do not represent flooding from any particular scenario event, but present an inundation line that reflects the worst inundation at this particular location among a range of scenario events. Current practice in tsunami resistant design relies on estimates of tsunami impact forces derived from empirical relationships that have been borrowed from riverine flooding calculations, which involve only inundation elevations. We examine this practice critically. Recent computational advances allow for calculation of additional parameters from scenario events such as the detailed distributions of tsunami currents and fluid accelerations, and this suggests that alternative and more comprehensive expressions for calculating tsunami impact and tsunami forces should be examined. We do so, using model output for multiple inundation simulations of Seaside, Oregon, as part of a pilot project to develop probabilistic tsunami hazard assessment methodologies for incorporation into FEMA Flood Insurance Rate Maps. We consider three different methods, compare the results with existing methodology for estimating forces and impact, and discuss the implications of these methodologies for probabilistic tsunami hazard assessment.

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

2004-12-01

199

TSUNAMI CATALOG AND VULNERABILITY OF MARTINIQUE (LESSER ANTILLES, FRANCE  

Directory of Open Access Journals (Sweden)

Full Text Available In addition to meteorological hazards (hurricanes, heavy rainfalls, long-period swells, etc., the Caribbean Islands are vulnerable to geological hazards such as earthquakes, landslides and volcanic eruptions caused by the complex tectonic activity and interactions in the region. Such events have generated frequently local or regional tsunamis, which often have affected the island of Martinique in the French West Indies. Over the past centuries, the island has been struck by destructive waves associated with local or regional events - such as those associated with the eruption of the Saint-Vincent volcano in 1902 and by tsunamis of distant origin as that generated by the 1755 Lisbon earthquake.The present study includes a classification of tsunamis that have affected Martinique since its discovery in 1502. It is based on international tsunami catalogs, historical accounts, and previous scientific studies and identifies tsunamigenic areas that could potentially generate destructive waves that could impact specific coastal areas of Martinique Island. The potential threat from tsunamis has been greatly increasing because of rapid urban expansion of coastal areas and development of tourism on the island.

Roger, J.

2010-01-01

200

Science of Tsunami Forecasting: 2010 Chilean Tsunami Challenge  

Science.gov (United States)

Tsunami forecasting with real-time models and real-time data has always been one of the main goals of tsunami research. The February 27th, 2010 Chile tsunami provided the challenge and the opportunity to test the modern state of the science in tsunami forecasting. By contrast with the previous basin-wide tsunami generated by the third largest 2004 Sumatra earthquake, the fifth largest Chilean earthquake occurred at the time and in the area where a variety of real-time measurements and model forecast models have been available to assess the generated tsunami in real-time. The Chile tsunami was generated by a Mw 8.8 earthquake (35.846S, 72.719W ), at 06:34 UTC, 115 km (60 miles) NNE of Concepcion, Chile (according to the USGS). It has been recorded at coastal sea level gages around the Pacific Ocean, staring from the near-field record that caught the wave half an hour after generation at Valparaiso, to the coastal recordings of the wave arrived at Japan and Russian Far East almost a day later. In approximately 3 hours after the earthquake, the tsunami was first recorded at DART buoy 32412, providing real-time deep ocean signature of the propagating tsunami. All that measurements provided ample data for the real-time forecast analysis and for the model performance and forecast skills assessment throughout the Pacific basin. We present results of the performance of the NOAA forecast. The forecast method uses MOST model with the data assimilated from the earthquake and deep-ocean tsunami DART measurement. The comparison with tide gages and coastal impacts provide opportunity to assess the accuracy and efficiency of the forecast. The successes, lessons learned and future challengers for the tsunami forecast science are discussed.

Titov, Vasily; Bernard, Eddie; Tang, Rachel; Wei, Yong; Uslu, Burak; Eble, Marie

2010-05-01

 
 
 
 
201

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

Science.gov (United States)

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

Fritz, Hermann M.

2014-05-01

202

Tsunami assignment  

Science.gov (United States)

Lectures and previous brief assignments dealt with plate tectonics, earthquakes, volcanoes and tsunamis. For the assignment, students read several articles describing potential sources for tsunamis on the east coast, including volcanic eruptions on the Canary Islands, underwater landslides off the shelf, and earthquakes. Their task is to summarize these potential sources, evaluate the risk of a tsunami on the east coast, and compare them with previously discussed risks for the west coast and Hawaii.

Neumann, Klaus

203

NEAR AND FAR-FIELD EFFECTS OF TSUNAMIS GENERATED BY THE PAROXYSMAL ERUPTIONS, EXPLOSIONS, CALDERA COLLAPSES AND MASSIVE SLOPE FAILURES OF THE KRAKATAU VOLCANO IN INDONESIA ON AUGUST 26-27, 1883  

Directory of Open Access Journals (Sweden)

Full Text Available The paroxysmal phases of Krakatau's volcanic activity on August 26-27, 1883, included numerous submarine Surtsean (phreatomagmatic eruptions, three sub air Plinian eruptions from the three main craters of Krakatau on Rakata island, followed by a fourth gigantic, sub air, Ultra-Plinian explosion. Landslides, flank failures, subsidences and a multiphase massive caldera collapse of the volcano - beginning near the Perbowetan crater on the northern portion of Rakata and followed by a collapse of the Danan crater - occurred over a period of at least 10 hours. The first of the three violent explosions occurred at 17: 07 Greenwich time (GMT on August 26.The second and third eruptions occurred at 05:30 GMT and at 06:44 GMT on August 27. Each of these events, as well as expanding gases from the submarine phreatomagmatic eruptions, lifted the water surrounding the island into domes or truncated cones that must have been about 100 meters or more in height. The height of the resulting waves attenuated rapidly away from the source because of their short periods and wavelengths. It was the fourth colossal explosion (VEI=6 and the subsequent massive f lank failure and caldera collapse of two thirds of Rakata Island, at 10:02 a.m., on August 27 that generated the most formidable of the destructive tsunami waves. A smaller fifth explosion, which occurred at 10:52 a.m., must have generated another large water cone and sizable waves. The final collapse of a still standing wall of Krakatau - which occurred several hours later at 16:38, generated additional waves.The near field effects of the main tsunami along the Sunda Strait in Western Java and Southern Sumatra, were devastating. Within an hour after the fourth explosion/caldera collapse, waves reaching heights of up to 37 m (120 feet destroyed 295 towns and villages and drowned a total of 36,417 people. Because of their short period and wavelength, the wave heights attenuated rapidly with distance away from the source region. It took approximately 2.5 hours for the tsunami waves to refract around Java and reach Batavia (Jakarta where the only operating tide gauge existed. Wavesof 2.4 meters in height were recorded - but with an unusually long period of 122 minutes. The long period is attributed to modification due to resonance effects and did not reflect source characteristics. The tsunami travel time to Surabaya at the eastern part of Java was 11.9 hours. The reported wave was only 0.2 meters.The far field effects of the tsunami were noticeable around the world, but insignificant. Small sea level oscillations were recorded by tide gauges at Port Blair in the Andaman Sea, at Port Elizabeth in South Africa, and as far away as Australia, New Zealand, Japan, Hawaii, Alaska, the North-American West Coast, South America, and even as far away as the English Channel. It took 12 hours for the tsunami to reach Aden on the southern tip of the Arabian Peninsula, about 3800 nautical miles away. The wave reported at Aden, at Port Blair and at Port Elizabeth, represents the actual tsunami generated in the Sunda Strait. There were no land boundaries on the Indian Ocean side of Krakatau to prevent the tsunami energy from spreading in that direction. The tsunami travel time of a little over 300 nautical miles per hour to Aden appears reasonable. However, it is doubtful that the waves, which were reported at distant locations in the Pacific or in the Atlantic Ocean, represented the actual tsunami generated in the Sunda Strait. Very little, if any at all, of the tsunami energy could have escaped the surrounding inland seas to the east of the Sunda Strait. Most probably, the small waves that were observed in the Pacific as well as in the Atlantic were generated by the atmospheric pressure wave of the major Krakatoa explosion, and not from the actual tsunami generated in the Sunda Strait. The unusual flooding, which occurred at the Bay of Cardiff, in the U.K., was caused by atmospheric coupling of the pressure wave from the major Krakatau eruption.

George Pararas-Carayannis

2003-01-01

204

Modelling of tsunami generated by the giant Late Bronze Age eruption of Thera, South Aegean Sea, Greece  

Science.gov (United States)

Tsunami generated by the Late Bronze Age (LBA) eruption of Thera were simulated using synthetic tide records produced for selected nearshore (˜20 m depths) sites of northern Crete, the Cyclades Islands, SW Turkey and Sicily. Inundation distances inland were also calculated along northern Crete. Modelling was performed by incorporating fully non-linear Boussinesq wave theory with two tsunamigenic mechanisms. The first involved the entry of pyroclastic flows into the sea, assuming a thick (55 m; 30 km3) flow entering the sea along the south coast of Thera in three different directions all directed towards northern Crete, then a thin pyroclastic flow (1 m; 1.2 km3) entering the sea along the north coast of Thera directed towards the Cyclades Islands. Flows were modelled as a solid block that slowly decelerates along a horizontal surface. The second mechanism assumed caldera collapse, of 19 km3 and 34 km3 modelled as a dynamic landslide producing rapid vertical displacements. Calculated nearshore wave amplitudes varied from a few metres to 28 m along northern Crete from pyroclastic flows, and up to 19 m from caldera collapse (34 km3 volume). Inundation distances on Crete were 250-450 m. Waves produced by pyroclastic flows were highly focused, however, as a function of sea entry direction. Smaller volume pyroclastic flows produced nearshore wave amplitudes up to 4 m in the Cyclades islands north of Thera. Wave amplitudes in the Cyclades from smaller volume caldera collapse (19 km3) were up to 24 m, whereas in SW Turkey were as low as 2.1 and 0.8 m (Didim and Fethye where LBA tsunami deposits have been found). Wave amplitudes for the larger volume caldera collapse (34 km3) were generally 2.5-3 times larger than those generated by the smaller volume collapse (19 km3). These results provide estimates for understanding possible consequences of tsunami impact in LBA coastal zones, thus providing criteria at archaeological sites for detecting inundation damage, as well as for contemporary hazard assessment; they also provide additional criteria for deciphering homogenite layers in the abyssal stratigraphy of the Ionian and eastern Mediterranean Seas.

Novikova, T.; Papadopoulos, G. A.; McCoy, F. W.

2011-08-01

205

The source of the 1722 Algarve earthquake: evidence from MCS and Tsunami data  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Abstract The 27 December 1722 Algarve earthquake destroyed a large area in southern Portugal generating a local tsunami that inundated the shallow areas of Tavira. It is unclear whether its source was located onshore or offshore and, in any case, what was the tectonic source responsible for the event. We analyze available historical information concerning macroseismicity and the tsunami to discuss the most probable location of the source. We also review available seismotectonic knowledge of ...

Baptista, M.; Miranda, J.; Lopes, Fernando; Luis, Joaquim

2007-01-01

206

Numerical modeling of the 1964 Alaska tsunami in western Passage Canal and Whittier, Alaska  

Directory of Open Access Journals (Sweden)

Full Text Available A numerical model of the wave dynamics in Passage Canal, Alaska during the Mw 9.2 megathrust earthquake is presented. During the earthquake, several types of waves were identified at the city of Whittier, located at the head of Passage Canal. The first wave is thought to have been a seiche, while the other two waves were probably triggered by submarine landslides. We model the seiche wave, landslide-generated tsunami, and tectonic tsunami in Passage Canal and compute inundation by each type of wave during the 1964 event. Modeled results are compared with eyewitness reports and an observed inundation line. Results of the numerical experiments let us identify where the submarine landslides might have occurred during the 1964 event. We identify regions at the head and along the northern shore of Passage Canal, where landslides triggered a wave that caused most of the damage in Whittier. An explanation of the fact that the 1964 tectonic tsunami in Whittier was unnoticed is presented as well. The simulated inundation by the seiche, landslide-generated tsunami, and tectonic tsunami can help to mitigate tsunami hazards and prepare Whittier for a potential tsunami.

D. J. Nicolsky

2010-12-01

207

Numerical modeling of the 1964 Alaska tsunami in western Passage Canal and Whittier, Alaska  

Science.gov (United States)

A numerical model of the wave dynamics in Passage Canal, Alaska during the Mw 9.2 megathrust earthquake is presented. During the earthquake, several types of waves were identified at the city of Whittier, located at the head of Passage Canal. The first wave is thought to have been a seiche, while the other two waves were probably triggered by submarine landslides. We model the seiche wave, landslide-generated tsunami, and tectonic tsunami in Passage Canal and compute inundation by each type of wave during the 1964 event. Modeled results are compared with eyewitness reports and an observed inundation line. Results of the numerical experiments let us identify where the submarine landslides might have occurred during the 1964 event. We identify regions at the head and along the northern shore of Passage Canal, where landslides triggered a wave that caused most of the damage in Whittier. An explanation of the fact that the 1964 tectonic tsunami in Whittier was unnoticed is presented as well. The simulated inundation by the seiche, landslide-generated tsunami, and tectonic tsunami can help to mitigate tsunami hazards and prepare Whittier for a potential tsunami.

Nicolsky, D. J.; Suleimani, E. N.; Hansen, R. A.

2010-12-01

208

Tsunami: Un problema matemáticamente interesante / Tsunami: An interesting mathematical problema  

Scientific Electronic Library Online (English)

Full Text Available SciELO Costa Rica | Language: Spanish Abstract in spanish Se presentan algunos aspectos fundamentales respecto a la matemática y la herramienta computacional que apoyan la compleja descripción del proceso físico tsunami desde dos enfoques específicos. En particular, se aborda analíticamente un modelo hidroelástico simple para el problema de generación de o [...] ndas tsunami, el cual permite obtener resultados en el área de ruptura. Por otra parte, el proceso de propagación de las ondas tsunami en el océano y el impacto a lo largo de la línea costera se analiza numéricamente utilizando el enfoque hidrodinámico, presentando en particular una aplicación directa sobre la predicción de tsunamis en México producidos por sismos potenciales en la trinchera Mesoamericana mediante el diseño de un “Módulo Sintetizador de Tsunamis” para simular tsunamis originados por sismos ocurridos en la zona de subducción de la costa occidental de México. Abstract in english We present some key aspects regarding the mathematics and the computational tool that support the complex description of the physical process tsunami from two specific approaches. In particular, it addresses analytically a simple hydroelastic model for the problem of tsunami wave generation, which p [...] rovides results in the rupture area. Moreover, the propagation of tsunami waves in the ocean and the impact along the coastline is analyzed numerically using the hydrodynamic approach, presenting in particular a direct application to the prediction of tsunamis in Mexico caused by potential earthquakes in the Mesoamerican trench through the design of a “Tsunami Toolbox” to simulate tsunamis caused by earthquakes in the subduction zone on the western coast of Mexico.

Rodrigo, González González; Modesto, Ortiz Figueroa; José Miguel, Montoya Rodríguez.

2012-01-01

209

Tsunami: Un problema matemáticamente interesante / Tsunami: An interesting mathematical problema  

Scientific Electronic Library Online (English)

Full Text Available SciELO Costa Rica | Language: Spanish Abstract in spanish Se presentan algunos aspectos fundamentales respecto a la matemática y la herramienta computacional que apoyan la compleja descripción del proceso físico tsunami desde dos enfoques específicos. En particular, se aborda analíticamente un modelo hidroelástico simple para el problema de generación de o [...] ndas tsunami, el cual permite obtener resultados en el área de ruptura. Por otra parte, el proceso de propagación de las ondas tsunami en el océano y el impacto a lo largo de la línea costera se analiza numéricamente utilizando el enfoque hidrodinámico, presentando en particular una aplicación directa sobre la predicción de tsunamis en México producidos por sismos potenciales en la trinchera Mesoamericana mediante el diseño de un “Módulo Sintetizador de Tsunamis” para simular tsunamis originados por sismos ocurridos en la zona de subducción de la costa occidental de México. Abstract in english We present some key aspects regarding the mathematics and the computational tool that support the complex description of the physical process tsunami from two specific approaches. In particular, it addresses analytically a simple hydroelastic model for the problem of tsunami wave generation, which p [...] rovides results in the rupture area. Moreover, the propagation of tsunami waves in the ocean and the impact along the coastline is analyzed numerically using the hydrodynamic approach, presenting in particular a direct application to the prediction of tsunamis in Mexico caused by potential earthquakes in the Mesoamerican trench through the design of a “Tsunami Toolbox” to simulate tsunamis caused by earthquakes in the subduction zone on the western coast of Mexico.

Rodrigo, González González; Modesto, Ortiz Figueroa; José Miguel, Montoya Rodríguez.

210

The April Fool's Tsunami of 1946: Lessons From Sumatra  

Science.gov (United States)

Submarine landslides are often invoked to explain very large runups because of "Plafker's rule of thumb" (corroborated by Okal &Synolakis), that maximum tsunami runup in the near field does not much exceed maximum slip of the generating earthquake. The huge (30 m) runups along the Aceh coast in 2004 do not require any landslide, however, because earthquake slip approached 30 m. From its tsunami alone, Tanioka &Seno have inferred similar large slip for the eastern Aleutian earthquake of 1 April 1946. But 1946 remains an enigma because the tsunami source region seems too small for the generating earthquake, and the earthquake, supposedly magnitude 8.5, occurred in a region of no strain accumulation. The unambiguous evidence of Sumatra, however, demands that the 1946 event be reexamined. The small source region of the 1946 tsunami depends critically on the one Japanese tide gauge that recorded the tsunami clearly, Hanasaki. But the calibration notations on the Hanasaki record are inconsistent with the identified tsunami arrival time, so the timing remains suspect. The lack of measurable strain is more difficult to dismiss: rupture areas of known great earthquakes (including both Sumatra 2004 and Alaska 1964) all show post-seismic or inter-seismic deformation, making the Unimak segment of the Aleutian Megathrust, and the adjacent Shumagin segment (which also shows no strain accumulation, despite a supposed great earthquake there in 1788), anomalous. A landslide in 1946 was invoked to explain 42 m runup at Scotch Cap, near the western end of Unimak Island. A multibeam survey of the Aleutian slope in 2004 showed that there is no landslide capable of producing such runup. While a landslide on the adjacent unsurveyed slope is possible, it would have to be so large that runup exceeded 50 m along Unimak Bight, the central Unimak coast. No evidence for such huge runup has yet been found, though the tsunami runup exceeded 22 m at Cape Pankof, the eastern extremity of the island. From Scotch Cap to Cape Pankof is 115 km. This compares to the 190 km from Banda Aceh to Meulaboh in Sumatra, the extent of >20 m runups in 2004. We remain uncertain of the origins of the 1946 tsunami. If the source was a landslide, then great ocean- crossing tsunamis can be generated without great earthquakes, which has serious implications for tsunami warning. But if, as comparison with Sumatra now suggests, the source turns out to be purely the earthquake, then we must infer that between major events it is possible for a megathrust to display no deformation at all. A few multibeam tracks would resolve the issue.

Fryer, G. J.; Tryon, M. D.

2006-12-01

211

Automated Testing with Targeted Event Sequence Generation  

DEFF Research Database (Denmark)

Automated software testing aims to detect errors by producing test inputs that cover as much of the application source code as possible. Applications for mobile devices are typically event-driven, which raises the challenge of automatically producing event sequences that result in high coverage. Some existing approaches use random or model-based testing that largely treats the application as a black box. Other approaches use symbolic execution, either starting from the entry points of the applications or on specific event sequences. A common limitation of the existing approaches is that they often fail to reach the parts of the application code that require more complex event sequences. We propose a two-phase technique for automatically finding event sequences that reach a given target line in the application code. The first phase performs concolic execution to build summaries of the individual event handlers of the application. The second phase builds event sequences backward from the target, using the summaries together with a UI model of the application. Our experiments on a collection of open source Android applications show that this technique can successfully produce event sequences that reach challenging targets.

Jensen, Casper Svenning; Prasad, Mukul R.

2013-01-01

212

BEGET: The B-Factory Event Generator Version 21  

Energy Technology Data Exchange (ETDEWEB)

This note is a reference manual for the B-Factory Event Generator (BEGET V21) software package which generates physics events relevant to B-Factory detector studies. The package provides a standard framework that can easily interface to various external generators and simulation applications. Version 21 of BEGET contains a number of physics and background generators and is interfaced to the JETSET and KORALB generators and the GEANT and ASLUND simulation programs.

Wright, D.M.

1994-08-15

213

Scenarios for earthquake-generated tsunamis on a complex tectonic area of diffuse deformation and low velocity: The Alboran Sea, Western Mediterranean  

Science.gov (United States)

The tsunami impact on the Spanish and North African coasts of the Alboran Sea generated by several reliable seismic tsunamigenic sources in this area was modeled. The tectonic setting is complex and a study of the potential sources from geological data is basic to obtain probable source characteristics. The tectonic structures considered in this study as potentially tsunamigenic are: the Alboran Ridge associated structures, the Carboneras Fault Zone and the Yusuf Fault Zone. We characterized 12 probable tsunamigenic seismic sources in the Alboran Basin based on the results of recent oceanographical studies. The strain rate in the area is low and therefore its seismicity is moderate and cannot be used to infer characteristics of the major seismic sources. These sources have been used as input for the numerical simulation of the wave propagation, based on the solution of the nonlinear shallow water equations through a finite-difference technique. We calculated the Maximum Wave Elevations, and Tsunami Travel Times using the numerical simulations. The results are shown as maps and profiles along the Spanish and African coasts. The sources associated with the Alboran Ridge show the maximum potential to generate damaging tsunamis, with maximum wave elevations in front of the coast exceeding 1.5. m. The Carboneras and Yusuf faults are not capable of generating disastrous tsunamis on their own, although their proximity to the coast could trigger landslides and associated sea disturbances. The areas which are more exposed to the impact of tsunamis generated in the Alboran Sea are the Spanish coast between Malaga and Adra, and the African coast between Alhoceima and Melilla. ?? 2011 Elsevier B.V.

Alvarez-Gomez, J. A.; Aniel-Quiroga, I.; Gonzalez, M.; Olabarrieta, M.; Carreno, E.

2011-01-01

214

Exploring tsunamis with non-traditional dataset: array recordings from temporary ocean-bottom seismic experiment  

Science.gov (United States)

We observe clear tsunami signals generated by the July 15, 2009 magnitude 7.8 Dusky Sound (Fiordland) New Zealand earthquake on seafloor differential pressure gauges (DPGs). The dataset was collected during the ocean-bottom seismic experiment, Marine Observations of Anisotropy Near Aotearoa (MOANA). This experiment deployed 30 broadband ocean-bottom seismometers (Trillium 240) and differential pressure gauges (DPGs) for a year (2009/01-2010/02) both in deep ocean (greater than 4000 m water depth) and on the continental shelf (550 m to 1300 m) offshore of the South Island of New Zealand. The DPGs are used in many US National Ocean Bottom Seismograph Instrument Pool (OBSIP) experiments and are designed to record seismic signals. In this study, we demonstrate that DPGs can effectively record open-ocean tsunami signals and the tsunami signals on DPG records can be used for tsunami studies. We carry out waveform and spectral analysis for DPG data recordings of the Fiordland tsunami event. The arrival times of tsunami signals on DPG recordings can be directly used to constrain tsunami wave propagation models. We calibrate the DPGs to obtain better control on the amplitude of the tsunami signals on the DPG records. Calibrations are done over frequency bands of both Rayleigh wave and tidal signals. Synthetic pressure waveforms are calculated to be compared with the DPG recorded signals.

Sheehan, A. F.; Yang, Z.; Nicolsky, D.; Mungov, G.; Eakins, B.

2011-12-01

215

Development of tsunami hazard maps for the Mentawai Islands, Indonesia, using heterogeneous slip models  

Science.gov (United States)

Heterogeneous distribution of slip during megathrust earthquakes has been shown to significantly affect the spatial distribution of tsunami height in both numerical studies and field observations. This means that tsunami hazard maps generated using uniform slip distributions in their tsunami source models may underestimate tsunami inundation in some locations compared with real events of the same magnitude in the same location. In order to more completely define areas that may be inundated during a tsunami it is important to consider how different possible distributions of slip will impact different parts of the coastline. We generate tsunami inundation maps for the Mentawai Islands, West Sumatra, Indonesia, from a composite suite of possible source models that are consistent with current knowledge of the source region. First, a suite of earthquake source models with randomly distributed slip along the Mentawai Segment of the Sunda Subduction Zone are generated. From this suite we select source models that generate vertical deformation consistent with that observed in coral palaeogeodetic records of previous ruptures of the Mentawai Segment. Tsunami inundation is modelled using high resolution elevation data for selected source models and the results compiled to generate a maximum tsunami inundation zone. This allows us to constrain the slip distribution beneath the Mentawai Islands, where coral palaeogeodetic data is available, while allowing greater variation in the slip distribution away from the islands, in particular near the trench where large slip events can generate large tsunami. This method also allows us to consider high slip events on deeper portions of the megathrust between the Mentawai Islands and the Sumatran Mainland, which give greater tsunami inundation on the eastern part of the Mentawai Islands and the west coast of Sumatra compared with near-trench events. By accounting for uncertainty in slip distribution, the resulting hazard maps give a more complete picture of the areas that may be inundated compared with hazard maps derived from a single ';worst case' source model. These maps allow for more robust tsunami evacuation plans to be developed to support immediate community evacuation in response to strong or long-lasting earthquake ground shaking.

Griffin, J.; Pranantyo, I. R.; Kongko, W.; Haunan, A.; Horspool, N.; Maemunah, I.; Natawidjaja, D.; Latief, H.; Cummins, P. R.

2013-12-01

216

Tohoku Tsunami Created Icebergs In Antarctica  

Science.gov (United States)

This website, from NASA, offers an article, images, and a video about the connection between the 2011 tsunami off the coast of Japan and a large ice calving event in Antarctica. Scientists observed ice calving soon after the Japan event and attributed it to the swell caused by the tsunami; this finding marks the first direct observation of such a connection between tsunamis and icebergs.

Lynch, Patrick; Nasa

217

Generating tsunami risk knowledge at community level as a base for planning and implementation of risk reduction strategies  

Science.gov (United States)

More than 4 million Indonesians live in tsunami-prone areas along the southern and western coasts of Sumatra, Java and Bali. Although a Tsunami Early Warning Center in Jakarta now exists, installed after the devastating 2004 tsunami, it is essential to develop tsunami risk knowledge within the exposed communities as a basis for tsunami disaster management. These communities need to implement risk reduction strategies to mitigate potential consequences. The major aims of this paper are to present a risk assessment methodology which (1) identifies areas of high tsunami risk in terms of potential loss of life, (2) bridges the gaps between research and practical application, and (3) can be implemented at community level. High risk areas have a great need for action to improve people's response capabilities towards a disaster, thus reducing the risk. The methodology developed here is based on a GIS approach and combines hazard probability, hazard intensity, population density and people's response capability to assess the risk. Within the framework of the GITEWS (German-Indonesian Tsunami Early Warning System) project, the methodology was applied to three pilot areas, one of which is southern Bali. Bali's tourism is concentrated for a great part in the communities of Kuta, Legian and Seminyak. Here alone, about 20 000 people live in high and very high tsunami risk areas. The development of risk reduction strategies is therefore of significant interest. A risk map produced for the study area in Bali can be used for local planning activities and the development of risk reduction strategies.

Wegscheider, S.; Post, J.; Zosseder, K.; Mück, M.; Strunz, G.; Riedlinger, T.; Muhari, A.; Anwar, H. Z.

2011-02-01

218

TSUNAMI HAZARD IN NORTHERN VENEZUELA  

Directory of Open Access Journals (Sweden)

Full Text Available Based on LANDSAT ETM and Digital Elevation Model (DEM data derived by the Shuttle Radar Topography Mission (SRTM, 2000 of the coastal areas of Northern Venezuela were investigated in order to detect traces of earlier tsunami events. Digital image processing methods used to enhance LANDSAT ETM imageries and to produce morphometric maps (such as hillshade, slope, minimum and maximum curvature maps based on the SRTM DEM data contribute to the detection of morphologic traces that might be related to catastrophic tsunami events. These maps combined with various geodata such as seismotectonic data in a GIS environment allow the delineation of coastal regions with potential tsunami risk. The LANDSAT ETM imageries merged with digitally processed and enhanced SRTM data clearly indicate areas that might be prone by flooding in case of catastrophic tsunami events.

B. Theilen-Willige

2006-01-01

219

Tsunami Propagation Database for the Mediterranean and Aegean Seas  

Science.gov (United States)

Pre-computed tsunami scenario databases are common tools to develop long- or short-term forecasting methodologies and hazard assessment approaches for tsunami-prone regions worldwide. The benefits of such databases include the possibility of probabilistic studies (Gonzalez et al., 2009, J. Geophys. Res. 114, Article Number: C11023), inundation mapping (Barberopoulou et al., 2011, Pure Appl. Geophys. 168(11), 2133-2146), or real-time forecasting (Wei et al., 2008, Geophys. Res. Lett. 35(4), Article Number: L04609). As a result, several tsunami propagation databases have been developed including one by NOAA's Pacific Marine Environmental Laboratory (PMEL), and another by the Australian Bureau of Meteorology (BOM). Pre-computed tsunami scenario databases utilize different approaches. PMEL's tsunami propagation database is based on the concept of a pre-computed tsunami scenarios consisting of propagation results from 100km x 50km fault planes with a slip value of 1m referred to as tsunami source functions. PMEL's source functions are placed along the subduction zones in several rows, covering known faults throughout the major ocean basins. Linearity of the tsunami propagation in the open ocean allows scaling and/or combination of the pre-computed tsunami source functions to generate a desired scenario. The BOM database considers five earthquakes with magnitudes changing from 7.0 to 9.0 at each location with 100km intervals along the subduction zone. However, to date, no similar approach has been computed along the subduction zones in the Aegean and Mediterranean Seas, even though, historically, there have been a considerable number of tsunami events which caused damage in the region (Ambraseys and Synolakis, 2010, J. Earthquake Eng. 14 (3), 309-330, Article Number: PII 919600673). A new project was initiated between Greece and Turkey supported by General Secretariat for Research & Technology, The Ministry for Development (GSRT) of Greece and The Scientific and Technological Research Council (TUBITAK) of Turkey in order to establish a tsunami propagation database primarily in the Aegean Sea but with a natural extension to the Mediterranean Sea. In this project, we placed unit sources of different lengths and widths, considering the local tectonics of the region (Papazachos, 1996, Ann. Geofis. 395, 891-903), i.e., 100km x 50km and 50km x 25km, along the subduction zones and at the proximity of historical events. We also located some historical sources as discussed in previous studies (Ebeling et al., 2012, Tectonophysics 530, 225-239). Model runs for this new propagation database are nearly completed, and preliminary inundation maps were developed for two coastal towns, one in each country. We extensively use the tsunami community modeling tool Community Model Interface for Tsunamis (ComMIT) which is designed for ease of use, and allows dissemination of results to the community while addressing concerns associated with proprietary issues of bathymetry and topography (Titov et al., 2011, Pure Appl. Geophys. 168(11), 2121-2131). We will discuss initial outcomes of the project including modeling of some historical tsunami events. Once finalized, we hope that this database will be extremely useful in developing tsunami-resilient communities in the region using both long- and short-term forecasting.

Kanoglu, U.; Hoto, O.; Kalligeris, N.; Flouri, E.; Aydin, B.; Moore, C. W.; Synolakis, C. E.

2012-12-01

220

Tsunami Deposit Data Base  

Science.gov (United States)

A digital database has been established describing tsunami deposits around the world (3 phases; 15 months). The projects involved the review and tabulation of data derived from books, catalogs, journals, preprints, citations and abstracts (currently 1000 references), into a database designed to provide a comprehensive review of the types of tsunami deposits, their geographic distribution and location, sedimentary characteristics, fossil content, age, preservation, run-up, wave height and inundation observations, etc. (34 parameters). The tsunami occurrences can be divided into many subjects, e.g., Volcanogenic (N=375), Seismites (N=49), Co-seismic (N=258), K/T Boundary Impact-triggered debris flows (N=97), Landslides (N=43), etc. Numerous publications compare tsunami deposits to storm deposits (N=38), or analyze the origin of megaboulders (N=22). Tsunami deposits occur throughout geologic time (Pre-Cambrian to present day), and because of plate tectonics, they occur along plate margins (primarily subduction zones) as well as interior to plates. In addition, they occur in epi-continental seas, fjords, etc. Few publications describe depositional processes. Deposits generated by tsunamis occur in multiple environments such as the marine, fresh water, and subaerial. Common characteristics of tsunami deposits include: 1) Deposition of thin sand sheets (can be normal, massive, inversely graded, chaotic or bimodal). 2) Erosional: basal uncomformity, mud balls, rip-up clasts, reworked fossils produced by scouring. 3) Lithology: Stacks of couplets reflecting marine incursions (often sands) into fresh water or subaerial environments (mud, soil, peat). 4) Fossil: Couplets reflects marine fossils, fresh water fossils or a mixed assemblage. 5) Geomorphology: The sand sheets taper landward and can rise in elevation. 6) Deformation: syn-depositional (soft sediments) and intraformational (stiff sediments).

Keating, B. H.; Wanink, M.

2007-05-01

 
 
 
 
221

Tsunami Mystery  

Science.gov (United States)

This radio broadcast explores some ideas about the cause of a 1946 tsunami which swept from Alaska through the Pacific and killed more than 150 people. The tsunami was one of the worst of the 20th Century. Scientists today still cannot agree on just what caused it. They think it was an earthquake, an undersea landslide, or possibly both. The answer may change how scientists study tsunamis and how people prepare for them. The clip is 6 minutes and 38 seconds in length.

222

The 2010 Mw 7.8 Mentawai earthquake: Very shallow source of a rare tsunami earthquake determined from tsunami field survey and near-field GPS data  

Science.gov (United States)

The Mw 7.8 October 2010 Mentawai, Indonesia, earthquake was a "tsunami earthquake," a rare type of earthquake that generates a tsunami much larger than expected based on the seismic magnitude. It produced a locally devastating tsunami, with runup commonly in excess of 6 m. We examine this event using a combination of high-rate GPS data, from instruments located on the nearby islands, and a tsunami field survey. The GPS displacement time series are deficient in high-frequency energy, and show small coseismic displacements (16 m. Our modeling results show that the combination of the small GPS displacements and large tsunami can only be explained by high fault slip at very shallow depths, far from the islands and close to the oceanic trench. Inelastic uplift of trench sediments likely contributed to the size of the tsunami. Recent results for the 2011 Mw 9.0 Tohoko-Oki earthquake have also shown shallow fault slip, but the results from our study, which involves a smaller earthquake, provide much stronger constraints on how shallow the rupture can be, with the majority of slip for the Mentawai earthquake occurring at depths of <6 km. This result challenges the conventional wisdom that the shallow tips of subduction megathrusts are aseismic, and therefore raises important questions both about the mechanical properties of the shallow fault zone and the potential seismic and tsunami hazard of this shallow region.

Hill, Emma M.; Borrero, Jose C.; Huang, Zhenhua; Qiu, Qiang; Banerjee, Paramesh; Natawidjaja, Danny H.; Elosegui, Pedro; Fritz, Hermann M.; Suwargadi, Bambang W.; Pranantyo, Ignatius Ryan; Li, Linlin; MacPherson, Kenneth A.; Skanavis, Vassilis; Synolakis, Costas E.; Sieh, Kerry

2012-06-01

223

A hydro-acoustic solution to the local tsunami warning problem  

Science.gov (United States)

We demonstrate the potential for using the spectral content of T-phases from earthquakes to identify events involves a component of splay faulting. There is significant evidence indicating that splay faulting explains extreme local tsunamis in events with more moderate distant tsunamis. For example, the distant tsunami from the Dec. 26, 2004 Megathrust is fully explained by the primary rupture. However, the local tsunami was significantly (3 to 4x larger) than predicted and 10 minutes early. The discrepancy can be explained by significant rupture along a splay fault approximately 90km west of Banda Aceh. The secondary rupture produces a high amplitude, short wavelength tsunami that is not resolvable seismically, as the softer sediments would produce significantly (1/40th to 1/100th) less seismic radiation than the primary rupture. However, the secondary rupture appears to generate observable hydroacoustic signals. The shallow rupture of the secondary source results in less anelastic attenuation, producing a shallower spectral slope of the T- phase than the much larger primary rupture. The observed signal is the combination of the weaker shallow secondary rupture and the much larger (and deeper) primary rupture. At low frequencies, the primary rupture dominates the spectral shape. At higher frequencies, the weaker shallow source predominates. We are able resolve the dual rupture in the case of Northern Sumatra. This is significant because, in the 378 earthquakes analyzed, only three events showed this pattern for more than 50 seconds; two of those events had anomalously large local Tsunamis: Northern Sumatra and Nias Island. The third event was an Mw 7.6 strike slip fault. It is thus likely that a significantly curved T-phase spectrum is indicative of secondary (possibly splay) sources, and increased likelihood of local tsunamis. A prototype system to identify the signatures of the secondary faulting has been developed and installed at the Pacific Tsunami Warning Center in Ewa Beach, HI.

Salzberg, D. H.

2008-12-01

224

Tsunami waves of seismic origin: The modern state of knowledge  

Science.gov (United States)

This review summarizes the concepts of seismogenic tsunami waves. Principles of short-term tsunami forecasting and tsunami recording systems are discussed. The traditional approach to describing tsunami generation by earthquakes is outlined and its drawbacks are analyzed. The main and secondary effects are distinguished which are responsible for the formation of waves by underwater earthquakes. The existing numerical codes of tsunami dynamics are described.

Nosov, M. A.

2014-09-01

225

Tsunami Source Specification for Southeast Alaska with Focus on Inundation Mapping and Hazard Risk Assessment in Sitka  

Science.gov (United States)

The Alaska Earthquake Information Center (AEIC) conducts tsunami inundation mapping for coastal communities in Alaska. This activity provides local emergency officials with tsunami hazard assessment and mitigation tools. At-risk communities are spread along several segments of the Alaska-Aleutian Subduction Zone, with each segment having a unique seismic history and potential tsunami hazard. As a result, almost every community has a distinct set of potential tsunami sources that need to be considered in order to make a tsunami inundation map. Therefore, an important component of the inundation mapping effort is identification and specification of potential tsunami sources. We are creating tsunami inundation maps for Sitka, Alaska, in the scope of the National Tsunami Hazard Mitigation Program. Tsunami potential from tectonic and submarine landslide sources must be evaluated in this case for comprehensive mapping of areas at risk for inundation. The community of Sitka, the former capital of Russian Alaska, is located in Southeast Alaska, on the west coast of Baranof Island, facing the Pacific Ocean. In this area of southern Alaska, the subduction of the Pacific plate beneath the North America plate becomes a transform boundary that continues down the coast as the Fairweather - Queen Charlotte (FW-QC) transform fault system. The Sitka segment of the FW-QC fault system ruptured in large strike-slip earthquakes in 1927 (Ms7.1) and in 1972 (Ms7.6). We numerically model the extent of inundation in Sitka due to tsunami waves generated from earthquake and landslide sources. Tsunami scenarios include a repeat of the tsunami triggered by the 1964 Great Alaska earthquake, repeat of the tsunami triggered by the 2011 Tohoku earthquake, tsunami waves generated by a hypothetically extended 1964 rupture, a hypothetical Cascadia megathrust earthquake, and hypothetical earthquakes in the FW-QC fault system. Underwater landslide events off the continental shelf along the FW-QC fault zone are also considered as credible tsunamigenic scenarios. We perform simulations for each of the scenarios using AEIC's numerical model of tsunami propagation and runup, which was validated through a set of analytical benchmarks and tested against laboratory and field data. Results of numerical modeling combined with historical observations in the region will be delivered to local emergency management to be used in local tsunami hazard assessment, evacuation planning and public education.

Suleimani, E. N.; Nicolsky, D. J.; Hansen, R. A.

2012-12-01

226

Puerto Rico Tsunami Warning and Mitigation Program-LANTEX 09 Survey  

Science.gov (United States)

Tsunami warning, assessment, education, mitigation and preparedness efforts seek to reduce losses related to tsunamis in Puerto Rico (PR). The PR Seismic Network (PRSN) works with governmental agencies and local communities to implement these tsunami hazard risk reduction programs. The Caribbean has a a history of destructive tsunamis such as Virgin Islands (1867), PR (1918) and Dominican Republic (1946). Tsunamis originating near PR are a near-field hazard for as they can reach coastal areas within minutes of a generating event. Sources for regional and tele tsunamis have been identified. To mitigate these risks to communities, the PR Tsunami Warning and Mitigation Program (PRTWMP) was established in 2000 with funding from FEMA, the University of Puerto Rico (UPR) and the PR State Emergency Management Agency (PRSEMA). With the support of NTHMP and TsunamiReady (TR), PR continues to seek to mitigate possible tsunami damages and increase community resilience by helping communities meet the TR guidelines by providing them inundation maps, helping them develop evacuation maps and emergency plans, assisting them with community outreach efforts and conducting evacuation drills. Currently 6 of 44 tsunami threatened communities in PR have been recognized as TsunamiReady. As part of this process, the PRSN, PRSEMA and various communities participated in the LANTEX 2009 tsunami exercise. This exercise took place on April 2, 2009 and was based on a scenario in which an earthquake northeast of PR generates a major tsunami which impacts PR and the USVI and threatens the states along the continental US eastern coast. The municipality of Mayagüez, a TsunamiReady community since 2006, participated in the exercise by activating its Emergency Operations Center , conducting evacuation drills in schools located within its tsunami exposed area, and activating its warning siren. This presentation highlights findings of UPRM social scientists collaborating with the PRTWMP who conducted a sample survey of residents of the Mayagüez tsunami evacuation area to serve as an assessment of the effectiveness of TsunamiReady outreach efforts and of the drill's warning efforts. 166 20-30 minute interviews were conducted during the month of April. Questions explored residents' perceptions of coastal hazards they may face; knowledge about tsunamis and how to react to them; use of mass media to obtain information about potential hazards; tsunami preparation efforts, including knowledge of the existence and location of assembly areas; and whether and how they received and understood the drill's warning messages. The sample's answers to the risk perception questions is compared to those obtained for the same questions from a sample of residents of storm surge areas in 8 municipalities along PR's west coast. This allows comparing tsunami hazard awareness among individuals exposed to the Tsunami Ready program efforts with that of residents of municipalities that are not part of it. This effort serves as an example of the multidisciplinary collaboration between physical and social scientists needed to increase the effectiveness and value of scientific knowledge as a tool to mitigate damages from natural hazards.

Diaz, W.; von Hillebrandt-Andrade, C.

2009-12-01

227

A deterministic analysis of tsunami hazard and risk for the southwest coast of Sri Lanka  

Science.gov (United States)

This paper describes a multi-scenario, deterministic analysis carried out as a pilot study to evaluate the tsunami hazard and risk distribution in the southwest coast of Sri Lanka. The hazard and risk assessment procedure adopted was also assessed against available field records of the impact of the Indian Ocean tsunami in 2004. An evaluation of numerically simulated nearshore tsunami amplitudes corresponding to ‘maximum-credible' scenarios from different subduction segments in the Indian Ocean surrounding Sri Lanka suggests that a seismic event similar to that generated the tsunami in 2004 can still be considered as the ‘worst-case' scenario for the southwest coast. Furthermore, it appears that formation of edge waves trapped by the primary waves diffracting around the southwest significantly influences the nearshore tsunami wave field and is largely responsible for relatively higher tsunami amplitudes in certain stretches of the coastline under study. The extent of inundation from numerical simulations corresponding to the worst-case scenario shows good overall agreement with the points of maximum penetration of inundation from field measurements in the aftermath of the 2004 tsunami. It can also be seen that the inundation distribution is strongly influenced by onshore topography. The present study indicates that the mean depth of inundation could be utilised as a primary parameter to quantify the spatial distribution of the tsunami hazard. The spatial distribution of the risk of the tsunami hazard to the population and residential buildings computed by employing the standard risk formula shows satisfactory correlation with published statistics of the affected population and the damage to residential property during the tsunami in 2004.

Wijetunge, J. J.

2014-05-01

228

A Tsunami PSA for Nuclear Power Plants in Korea  

Energy Technology Data Exchange (ETDEWEB)

For the evaluation of safety of NPP caused by Tsunami event, probabilistic safety assessment (PSA) method was applied in this study. At first, an empirical tsunami hazard analysis performed for an evaluation of tsunami return period. A procedure for tsunami fragility methodology was established, and target equipment and structures for investigation of Tsunami Hazard assessment were selected. A several fragility calculations were performed for equipment in Nuclear Power Plant and finally accident scenario of tsunami event in NPP was presented. Finally, a system analysis performed in the case of tsunami event for an evaluation of a CDF of Ulchin 56 NPP site. For the evaluation of safety of NPP caused by Tsunami event, probabilistic safety assessment (PSA) method was applied. A procedure for tsunami fragility methodology was established, and target equipment and structures for investigation of Tsunami Hazard assessment were selected. A several fragility calculations were performed for equipment in Nuclear Power Plant and finally accident scenario of tsunami event in NPP was presented. As a result, in the case of tsunami event, functional failure is mostly governed total failure probability of facilities in NPP site

Kim, Min Kyu; Choi, In Kil; Park, Jin Hee; Seo, Kyung Suk; Seo, Jeong Moon; Yang, Joon Eon

2010-06-15

229

A Tsunami PSA for Nuclear Power Plants in Korea  

International Nuclear Information System (INIS)

For the evaluation of safety of NPP caused by Tsunami event, probabilistic safety assessment (PSA) method was applied in this study. At first, an empirical tsunami hazard analysis performed for an evaluation of tsunami return period. A procedure for tsunami fragility methodology was established, and target equipment and structures for investigation of Tsunami Hazard assessment were selected. A several fragility calculations were performed for equipment in Nuclear Power Plant and finally accident scenario of tsunami event in NPP was presented. Finally, a system analysis performed in the case of tsunami event for an evaluation of a CDF of Ulchin 56 NPP site. For the evaluation of safety of NPP caused by Tsunami event, probabilistic safety assessment (PSA) method was applied. A procedure for tsunami fragility methodology was established, and target equipment and structures for investigation of Tsunami Hazard assessment were selected. A several fragility calculations were performed for equipment in Nuclear Power Plant and finally accident scenario of tsunami event in NPP was presented. As a result, in the case of tsunami event, functional failure is mostly governed total failure probability of facilities in NPP site

230

SOME OPPORTUNITITES OF THE LANDSLIDE TSUNAMI HYPOTHESIS  

Directory of Open Access Journals (Sweden)

Full Text Available Tsunami sources are intimately linked to geological events. Earthquakes and landslides are shown to be part of a continuum of complicated geological phenomena. Advances in landslide tsunami research will remain coupled with marine geology research. The landslide tsunami hypothesis is shown to have originated in the scientific literature in the early 1900s. Tsunami science has been slow to embrace the hypothesis in part because of the tremendous uncertainity that it introduces into tsunami gneration. The 1998 Papua New Guyinea event sparked much controbersy regarding the landslide tsunami hypothesis despite a preponderance of the evidence in favor of one simple and consistent explanation of the tsunami source. Part of the difficulty was the unanticipated distinction between slide and slump tsunami sources. Significant controversies still exist over other aspects of the Papua New Guinea event. The landslide hypothesis will become widely acceepted once direct measurements of underwater landslide events are made. These measurements will likely be integrated into a local tsunami warning system.

Phillip Watts

2001-01-01

231

February 27, 2010 Chilean Tsunami in Pacific and its Arrival to North East Asia  

Science.gov (United States)

The outskirts of the fault plane broken by the strong earthquake on February 27, 2010 in Chili with a magnitude 8.8 at the 35km depth of 35.909°S, 72.733°W coordinates generated a moderate size tsunami. The initial amplitude of the tsunami source is not so high because of the major area of the plane was at land. The tsunami waves propagated far distances in South and North directions to East Asia and Wet America coasts. The waves are also recorded by several gauges in Pacific during its propagation and arrival to coastal areas. The recorded and observed amplitudes of tsunami waves are important for the potential effects with the threatening amplitudes. The event also showed that a moderate size tsunami can be effective even if it propagates far distances in any ocean or a marginal sea. The far east coasts of Russia at North East Asia (Sakhalin, Kuriles, Kamchatka) are one of the important source (i.e. November 15, 2006, Kuril Island Tsunami) and target (i.e. February, 27, 2010 Chilean tsunami) areas of the Pacific tsunamis. Many efforts have been spent for establishment of the monitoring system and assessment of tsunamis and development of the mitigation strategies against tsunamis and other hazards in the region. Development of the computer technologies provided the advances in data collection, transfer, and processing. Furthermore it also contributed new developments in computational tools and made the computer modeling to be an efficient tool in tsunami warning systems. In this study the tsunami numerical model NAMI DANCE Nested version is used. NAMI-DANCE solves Nonlinear form of Long Wave (Shallow water) equations (with or without dispersion) using finite difference model in nested grid domains from the source to target areas in multiprocessor hardware environment. It is applied to 2010 Chilean tsunami and its propagation and coastal behavior at far distances near Sakhalin, Kuril and Kamchatka coasts. The main tide gauge records used in this study are from Petropavlosk (Kamchatka), Severo-Kurilsk (Paramushir), Kurilsk (Iturup, coast of the Okhotsk sea), Malokurilskoe (Shikotan), Korsakov, Kholmsk and Aniva Bay (Sakhalin). These records and also other offshore DART records are analyzed and used for comparison of the modeling results with offshore and nearshore records. The transmission of tsunami waves through Sakhalin and Kuril straits and their propagation to nearby coasts are investigated. The spectral analysis of records in settlements of Sakhalin and Kurile Islands are investigated. The performance and capabilities of NAMI DANCE is also presented together with comparisons between the model, observations and discussions.

Zaytsev, Andrey; Pelinovsky, EfiM.; Yalciner, Ahmet C.; Ozer, Ceren; Chernov, Anton; Kostenko, Irina; Shevchenko, Georgy

2010-05-01

232

Field Survey of the 29 September 2009 Tsunami on Savai’i Island, Samoa  

Science.gov (United States)

On 29 September, 2009 a magnitude Mw 8.1 earthquake occurred 200 km south of Samoa’s largest island Savai’i and triggered a tsunami which caused substantial damage and loss of life in Samoa, American Samoa and Tonga. The most recent estimate is that the tsunami caused 189 fatalities with the majority on Samoa’s Upolu Island, while only two deaths are confirmed on Savai’i. This marks the deadliest tsunami in Polynesia and Micronesia to the east of New Guinea since the 1975 Bougainville Island tsunami. PTWC responded and issued warnings soon after the earthquake but, because the tsunami arrived within 15 minutes at many locations, was too late to trigger evacuations. Fortunately, the people of Samoa knew to go to high ground after an earthquake because of education and tsunami evacuation exercises initiated throughout the South Pacific after a similar magnitude earthquake and tsunami struck the nearby Solomon Islands in 2007. A multi-disciplinary reconnaissance survey team was deployed within days of the event to document flow depths, runup heights, inundation distances, sediment deposition, damage patterns at various scales, and performance of the man-made infrastructure and impact on the natural environment. The ITST circled Savai’i Island from 8 to 9 October 2009 and collected more than 30 runup and flow depth measurements. The tsunami impact on Savai’i peaked with maximum runup exceeding 8 m at uninhabited Nuu Black Sand Beach located 7 km east of Cape Asuisui marking the center of the south coast. A significant variation in tsunami impact was observed on Savaii. The tsunami runup reached 6 m at Taga located 3 km to the east of Cape Asuisui, while along the northeast coast the runup remained below 3 m. The inundation distance at Taga approached 200 m and massive boulder fields covered the previously vegetated terrain more than 100 m inland. Fortunately no victims were reported at this location during this event, while the presumably smaller 1981 tsunami claimed one fatality at Taga. Savai’i was severely impacted by Category 5 tropical Cyclone Val in December 1991 causing 13 deaths and destroying about half of the island's coconut trees, resulting in a tremendous loss to the country's economy. Field observations and satellite imagery are presented. The team interviewed numerous eyewitnesses and educated residents about the tsunami hazard. Community-based education and awareness programs are essential to save lives in locales at risk from locally generated tsunamis.

Weiss, R.; Fritz, H. M.

2009-12-01

233

SEDIMENT CHARACTERISTICS OF THE M-9 TSUNAMI EVENT BETWEEN RAMESWARAM AND THOOTHUKUDI, GULF OF MANNAR, SOUTHEAST COAST OF INDIA  

Directory of Open Access Journals (Sweden)

Full Text Available On 26th December, 2004, a massive earthquake occurred NW of Sumatra in the seismically active zone close to Sunda Trench at a water depth of about 1300m and with an epicenter located at a shallow depth of 10km below the ocean floor. This earthquake triggered tsunami waves in the Indian Ocean and hit most of the Tamilnadu coast, with wave height varying from 3 to 10m. In the study area dunes were breached. Erosional channels were created. Inundation in the study area ranges between 10 and 600m from the shoreline. The inundated sediment thickness varies from 1 to 30cm and was well preserved. Sediments thickness gets reduced landwards and occurs as set of layers. The sediments were fresh, grey to dark grey in color.

S.R.Singarasubramanian

2006-01-01

234

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

Science.gov (United States)

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

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

2012-01-01

235

Assessment of Nearshore Hazard due to Tsunami-Induced Currents (Invited)  

Science.gov (United States)

The California Tsunami Program coordinated by CalOES and CGS in cooperation with NOAA and FEMA has begun implementing a plan to increase awareness of tsunami generated hazards to the maritime community (both ships and harbor infrastructure) through the development of in-harbor hazard maps, offshore safety zones for boater evacuation, and associated guidance for harbors and marinas before, during and following tsunamis. The hope is that the maritime guidance and associated education and outreach program will help save lives and reduce exposure of damage to boats and harbor infrastructure. An important step in this process is to understand the causative mechanism for damage in ports and harbors, and then ensure that the models used to generate hazard maps are able to accurately simulate these processes. Findings will be used to develop maps, guidance documents, and consistent policy recommendations for emergency managers and port authorities and provide information critical to real-time decisions required when responding to tsunami alert notifications. The goals of the study are to (1) evaluate the effectiveness and sensitivity of existing numerical models for assessing maritime tsunami hazards, (2) find a relationship between current speeds and expected damage levels, (3) evaluate California ports and harbors in terms of tsunami induced hazards by identifying regions that are prone to higher current speeds and damage and to identify regions of relatively lower impact that may be used for evacuation of maritime assets, and (4) determine ';safe depths' for evacuation of vessels from ports and harbors during a tsunami event. This presentation will focus on the results from five California ports and harbors, and will include feedback we have received from initial discussion with local harbor masters and port authorities. This work in California will form the basis for tsunami hazard reduction for all U.S. maritime communities through the National Tsunami Hazard Mitigation Program.

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

2013-12-01

236

Tsunamis in the central part of the Caspian Sea  

Science.gov (United States)

This paper describes the geotectonics of the Caspian Sea basin and the seismicity of its central part. The seismicity analysis enables us to identify the most probable zones of tsunami generation. We also present a brief review of the historical records of tsunamis in the Caspian Sea. In order to estimate the tsunami risk, we used the method of numerical hydrodynamic simulation while taking into account the real topography of the Caspian Sea. The computation of the wave field for the possible tsunamis occurring in the central part of the Caspian Sea allowed us to estimate the maximum expected heights of the waves along the coast of the CIS countries (Russia, Azerbaijan, Kazakhstan, and Turkmenistan). On the basis of the earthquake statistics in the region and the results of numerical experiments, we show that the extreme wave heights can reach 10 m at certain parts of the coast. Such extreme events correspond to extended (up to 200 km) seismic sources with M S ˜ 8 and a recurrence period of T ? 1600 years. The tsunami wave heights are expected to be as high as 3 m for sources of lesser extent (<50 km) with earthquake magnitudes of M S ˜ 7 and a recurrence period of 200 years.

Kulikov, E. A.; Kuzin, I. P.; Yakovenko, O. I.

2014-07-01

237

The Source Mechanism of 1939 Black Sea Tsunami  

Science.gov (United States)

The Black sea is surrounded by Turkey at South, Bulgaria, Romania and Moldovia at west, Russia and Ukraine at North, Georgia at East. The Great Erzincan Earthquake occurred on December 26, 1939 at 23:57 (GMT) in Turkey. This earthquake is remarkable not only because of its devastating casualties (39000), but also because of the tsunami generation in the Black sea [Richter, 1958]. The recorded epicenter coordinates (39.51oE, 39.80oN) was on land and approximately 60 km away from the south coast of the Black sea. The earthquake was shallow (26 km). The surface magnitude was 8 (maximal value for tsunami-generic earthquake in the Black Sea), and intensity of the earthquake was 11-12 [Nikonov, 1997]. Tsunami waves were observed at south coast of the Black sea near Fatsa, Ordu and Giresun towns in Turkey and recorded at North coast near Sebastopol, Yalta, Novorossiysk, Tuapse, and at East near poti and Batumi. The sea receded 50m, and then advanced 20m near Fatsa town. The sea also receded 50-60 m in Giresun, moreover in Ordu, the eyewitnesses at the harbor observed that sea initially was calm, then receded about 15 m. and returned its original position in 5-10 minutes [Altynok and Ersoy, 2000]. The tsunami crossed the Black Sea and was recorded on tide-gauges in Soviet harbors with height 50 cm in Sevastopol and Novorossiysk, and 40 cm in Tuapse. The intensity of this tsunami can be considered as intensity III-V according to new tsunami intensity scale of [Papadopoulos and Imamura, 2001]. Since the epicenter of the earthquake is far from the sea, the source mechanism of this tsunami is uncertain. The wave might have originated by either directly from rupture, or by the secondary fault in the Black sea, or by a submarine landslide triggered by the earthquake. The available data of tide gauge measurements, and observations can be used to compare the model results with different source mechanisms and initial conditions. The initial wave with different assumptions of source mechanisms for 1939 event are used in simulation. The arrival times of the tsunami waves, the initial sign of the wave form, the wave period and the nearshore tsunami amplitudes are computed at selected coastal stations. The computed tsunami records at the coastal locations are compared with the available data. The comparison of the observational, instrumental and numerical data at the shore locations are used for analysis and comparison of the assumed source mechanisms. The probable source mechanism of 1939 Black sea Tsunami is also discussed. Altynok, Y. and _. Ersoy (2000), Tsunamis observed on and near the Turkish coast. Natural Hazards, 21, 185-20. Nikonov, A. A. (1997), Tsunami occurrence on the coasts of the Black Sea and the Sea of Azov. Izvestiya, Physics of Solid Earth, 33, 72 - 87. Papadopoulos, G.A. and F. Imamura (2001), A proposal for a new tsunami intensity scale, Proceedings of International Tsunami Symposium 2001, Seattle, Washington, Aug. 7 -10, 2001, 569- 577. Richter C. F. (1958), Elementary Seismology, W. H, Freeman and Co., San Francisco, California, 1958

Yalciner, A. C.; Pelinovsky, E. N.

2004-05-01

238

General-purpose event generators for LHC physics  

CERN Document Server

We review the physics basis, main features and use of general-purpose Monte Carlo event generators for the simulation of proton-proton collisions at the Large Hadron Collider. Topics included are: the generation of hard-scattering matrix elements for processes of interest, at both leading and next-to-leading QCD perturbative order; their matching to approximate treatments of higher orders based on the showering approximation; the parton and dipole shower formulations; parton distribution functions for event generators; non-perturbative aspects such as soft QCD collisions, the underlying event and diffractive processes; the string and cluster models for hadron formation; the treatment of hadron and tau decays; the inclusion of QED radiation and beyond-Standard-Model processes. We describe the principal features of the ARIADNE, Herwig++, PYTHIA 8 and SHERPA generators, together with the Rivet and Professor validation and tuning tools, and discuss the physics philosophy behind the proper use of these generators ...

Buckley, Andy; Gieseke, Stefan; Grellscheid, David; Hoche, Stefan; Hoeth, Hendrik; Krauss, Frank; Lonnblad, Leif; Nurse, Emily; Richardson, Peter; Schumann, Steffen; Seymour, Michael H; Sjostrand, Torbjorn; Skands, Peter; Webber, Bryan

2011-01-01

239

Integrating Caribbean Seismic and Tsunami Hazard into Public Policy and Action  

Science.gov (United States)

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.

von Hillebrandt-Andrade, C.

2012-12-01

240

Web-based Tsunami Early Warning System: a case study of the 2010 Kepulaunan Mentawai Earthquake and Tsunami  

Directory of Open Access Journals (Sweden)

Full Text Available This study analyzes the response of the Global Disasters Alerts and Coordination System (GDACS in relation to a case study: the Kepulaunan Mentawai earthquake and related tsunami, which occurred on 25 October 2010. The GDACS, developed by the European Commission Joint Research Center, combines existing web-based disaster information management systems with the aim to alert the international community in case of major disasters. The tsunami simulation system is an integral part of the GDACS. In more detail, the study aims to assess the tsunami hazard on the Mentawai and Sumatra coasts: the tsunami heights and arrival times have been estimated employing three propagation models based on the long wave theory. The analysis was performed in three stages: (1 pre-calculated simulations by using the tsunami scenario database for that region, used by the GDACS system to estimate the alert level; (2 near-real-time simulated tsunami forecasts, automatically performed by the GDACS system whenever a new earthquake is detected by the seismological data providers; and (3 post-event tsunami calculations using GCMT (Global Centroid Moment Tensor fault mechanism solutions proposed by US Geological Survey (USGS for this event. The GDACS system estimates the alert level based on the first type of calculations and on that basis sends alert messages to its users; the second type of calculations is available within 30–40 min after the notification of the event but does not change the estimated alert level. The third type of calculations is performed to improve the initial estimations and to have a better understanding of the extent of the possible damage. The automatic alert level for the earthquake was given between Green and Orange Alert, which, in the logic of GDACS, means no need or moderate need of international humanitarian assistance; however, the earthquake generated 3 to 9 m tsunami run-up along southwestern coasts of the Pagai Islands where 431 people died. The post-event calculations indicated medium-high humanitarian impacts.

E. Ulutas

2012-06-01

 
 
 
 
241

The 25 October 2010 Mentawai tsunami earthquake (Mw 7.8) and the tsunami hazard presented by shallow megathrust ruptures  

Science.gov (United States)

The 25 October 2010 Mentawai, Indonesia earthquake (Mw 7.8) ruptured the shallow portion of the subduction zone seaward of the Mentawai islands, off-shore of Sumatra, generating 3 to 9 m tsunami run-up along southwestern coasts of the Pagai Islands that took at least 431 lives. Analyses of teleseismic P, SH and Rayleigh waves for finite-fault source rupture characteristics indicate ˜90 s rupture duration with a low rupture velocity of ˜1.5 km/s on the 10° dipping megathrust, with total slip of 2-4 m over an ˜100 km long source region. The seismic moment-scaled energy release is 1.4 × 10-6, lower than 2.4 × 10-6 found for the 17 July 2006 Java tsunami earthquake (Mw 7.8). The Mentawai event ruptured up-dip of the slip region of the 12 September 2007 Kepulauan earthquake (Mw 7.9), and together with the 4 January 1907 (M 7.6) tsunami earthquake located seaward of Simeulue Island to the northwest along the arc, demonstrates the significant tsunami generation potential for shallow megathrust ruptures in regions up-dip of great underthrusting events in Indonesia and elsewhere.

Lay, T.; Ammon, C. J.; Kanamori, H.; Yamazaki, Y.; Cheung, K. F.; Hutko, A. R.

2011-03-01

242

Concept study of radar sensors for near-field tsunami early warning  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Off-shore detection of tsunami waves is a critical component of an effective tsunami early warning system (TEWS). Even more critical is the off-shore detection of local tsunamis, namely tsunamis that strike coastal areas within minutes after generation. In this paper we propose new concepts for near-field tsunami early detection, based on innovative and up-to-date microwave remote sensing techniques. We particularly introduce the NESTRAD (NEar-Space Tsunami RADar) concept, which consists of a...

Bo?rner, T.; Galletti, M.; Marquart, N. P.; Krieger, G.

2010-01-01

243

Reconnaissance Survey of the 29 September 2009 Tsunami on Tutuila Island, American Samoa  

Science.gov (United States)

On 29 September, 2009 a magnitude Mw 8.1 earthquake occurred 200 km southwest of American Samoa’s Capital of Pago Pago and triggered a tsunami which caused substantial damage and loss of life in Samoa, American Samoa and Tonga. The most recent estimate is that the tsunami caused 189 fatalities, including 34 in American Samoa. This is the highest tsunami death toll on US territory since the 1964 great Alaskan earthquake and tsunami. PTWC responded and issued warnings soon after the earthquake but, because the tsunami arrived within 15 minutes at many locations, was too late to trigger evacuations. Fortunately, the people of Samoa knew to go to high ground after an earthquake because of education and tsunami evacuation exercises initiated throughout the South Pacific after a similar magnitude earthquake and tsunami struck the nearby Solomon Islands in 2007. A multi-disciplinary reconnaissance survey team was deployed within days of the event to document flow depths, runup heights, inundation distances, sediment deposition, damage patterns at various scales, and performance of the man-made infrastructure and impact on the natural environment. The 4 to 11 October 2009 ITST circled American Samoa’s main island Tutuila and the small nearby island of Aunu’u. The American Samoa survey data includes nearly 200 runup and flow depth measurements on Tutuila Island. The tsunami impact peaked with maximum runup exceeding 17 m at Poloa located 1.5 km northeast of Cape Taputapu marking Tutuila’s west tip. A significant variation in tsunami impact was observed on Tutuila. The tsunami runup reached 12 m at Fagasa near the center of the Tutuila’s north coast and 9 m at Tula near Cape Matatula at the east end. Pago Pago, which is near the center of the south coast, represents an unfortunate example of a village and harbor that was located for protection from storm waves but is vulnerable to tsunami waves. The flow patterns inside Pago Pago harbor were characterized based on vessel motions. The runup was a few meters at the bay entrance and peaked at 8 m only a few kilometers away at the head of the bay. Inundation and damage occurred more than 500 m inland at Pago Pago along the Vaipito River. Similar inundation distances were observed along the river at Leone. Field observations, video recordings and satellite imagery are presented. The team interviewed numerous eyewitnesses and educated residents about the tsunami hazard. Community-based education and awareness programs are essential to save lives in locales at risk from locally generated tsunamis.

Fritz, H. M.; Borrero, J. C.; Okal, E.; Synolakis, C.; Weiss, R.; Jaffe, B. E.; Lynett, P. J.; Titov, V. V.; Foteinis, S.; Chan, I.; Liu, P.

2009-12-01

244

Animation of the July 17, 1998, Papua New Guinea Tsunami  

Science.gov (United States)

On July 17, 1998, an earthquake registering 7.1 on the richter scale caused a tsunami along the coast of Papua New Guinea, wiping out two villages. The US Geological Survey (USGS) provides a model of the tsunami along with background information and news stories about the event. The animation is available in four formats and resolutions. Those who want to learn more about tsunamis can take advantage of the site's links under the heading General Information about Tsunamis.

245

UNDERSTANDING TSUNAMI RISK TO STRUCTURES: A CANADIAN PERSPECTIVE  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The potential catastrophic effects of tsunami-induced loading on built infrastructure in the vicinity of shorelines have been brought to the fore by recent global events. However, state- of-the-art building codes remain silent or provide conflicting guidance on designing near- shoreline structures in tsunami-prone areas. This paper focuses on tsunami-induced loading and its effect on structures within the Canadian context. The mechanics of tsunami-induced loading is described based on knowled...

Palermo, D.; Nistor, I.

2008-01-01

246

New approach to analysis of strongest earthquakes with upper-value magnitude in subduction zones and induced by them catastrophic tsunamis on examples of catastrophic events in 21 century  

Science.gov (United States)

The study of generation of strongest earthquakes with upper-value magnitude (near above 9) and induced by them catastrophic tsunamis, is performed by authors on the basis of new approach to the generation process, occurring in subduction zones under earthquake. The necessity of performing of such studies is connected with recent 11 March 2011 catastrophic underwater earthquake close to north-east Japan coastline and following it catastrophic tsunami which had led to vast victims and colossal damage for Japan. The essential importance in this study is determined by unexpected for all specialists the strength of earthquake occurred (determined by magnitude M = 9), inducing strongest tsunami with wave height runup on the beach up to 10 meters. The elaborated by us model of interaction of ocean lithosphere with island-arc blocks in subduction zones, with taking into account of incomplete stress discharge at realization of seismic process and further accumulation of elastic energy, permits to explain arising of strongest mega-earthquakes, such as catastrophic earthquake with source in Japan deep-sea trench in March, 2011. In our model, the wide possibility for numerical simulation of dynamical behaviour of underwater seismic source is provided by kinematical model of seismic source as well as by elaborated by authors numerical program for calculation of tsunami wave generation by dynamical and kinematical seismic sources. The method obtained permits take into account the contribution of residual tectonic stress in lithosphere plates, leading to increase of earthquake energy, which is usually not taken into account up to date.

Garagash, I. A.; Lobkovsky, L. I.; Mazova, R. Kh.

2012-04-01

247

What Causes Tsunamis?  

Science.gov (United States)

On December 26, 2004, a disastrous tsunami struck many parts of South Asia. The scope of this disaster has resulted in an outpouring of aid throughout the world and brought attention to the science of tsunamis. "Tsunami" means "harbor wave" in Japanese, and the Japanese have a long history of tsunamis. The word "tsunami" brings to mind one…

Mogil, H. Michael

2005-01-01

248

A new multi-sensor approach to simulation assisted tsunami early warning  

Science.gov (United States)

A new tsunami forecasting method for near-field tsunami warning is presented. This method is applied in the German-Indonesian Tsunami Early Warning System, as part of the Indonesian Tsunami Warning Center in Jakarta, Indonesia. The method employs a rigorous approach to minimize uncertainty in the assessment of tsunami hazard in the near-field. Multiple independent sensors are evaluated simultaneously in order to achieve an accurate estimation of coastal arrival times and wave heights within very short time after a submarine earthquake event. The method is validated employing a synthetic (simulated) tsunami event, and in hindcasting the minor tsunami following the Padang 30 September 2009 earthquake.

Behrens, J.; Androsov, A.; Babeyko, A. Y.; Harig, S.; Klaschka, F.; Mentrup, L.

2010-06-01

249

ZONAS OSCURAS EN EL SISTEMA DE ALARMA DE ADVERTENCIA DE TSUNAMI EN CHILE / DARK ZONES IN ALARM SYSTEM OF TSUNAMI OF WARNING OF TSUNAMI IN CHILE  

Scientific Electronic Library Online (English)

Full Text Available SciELO Chile | Language: Spanish Abstract in spanish El territorio chileno cuenta con alrededor de 80.000 km de costa considerando el territorio insular, un dato relevante al momento de considerar la ocurrencia de un tsunami. Las autoridades chilenas, conscientes de este extenso territorio marítimo, han desarrollado un sistema de alerta de tsunami com [...] o una responsabilidad estatal y han depositado su control a la oficina nacional de emergencia – ministerio del interior (ONEMI) y en el servicio hidrográfico y oceanográfico de la armada de Chile (SHOA). En este artículo hemos realizado experiencias con el objetivo de activar los sistemas de advertencias generando eventos telúricos ficticios y/o eventos telúricos históricos capaces de desatar eventos de tsunami. También se ha propuesto una hipótesis de trabajo que permita, a través de los procedimientos establecidos por ley de la República de Chile, monitorear los tiempos de respuestas de los organismos estatales. Nuestro trabajo de investigación entrega resultados que nos permiten afirmar que existen zonas para eventos hipotéticos que podrían generar tsunamis a los cuales el sistema de alerta no sería eficiente en reaccionar. Para llevar a cabo esta investigación hemos utilizado un software llamado SLAT, basado en ecuaciones simplificadas de propagación de una onda de tsunami que nos permite obtener resultados rápidos y además hemos sometido a prueba el sistema con datos oficiales en los cuales se ha demostrado que el sistema de alerta no fue capaz de reaccionar al evento Atico 8,4 M. ocurrido en Perú. Abstract in english The Chilean territory has an extensive coastline -about 80.000 km of coast including the territory of its islands – which is an important fact to consider in the event of the occurrence of a tsunami. The Chilean authorities, fully aware of the vast maritime territory, have developed a tsunami warnin [...] g system. This system constitutes a state responsibility, and its control has been entrusted to the national emergency office - ministry of interior (ONEMI) and hydrographic and oceanographic service of Chilean navy (SHOA). This article deals with experiences carried out in order to activate the warning systems, generating fictional telluric events and / or historical telluric events capable of triggering tsunami occurrences. It also proposes a working hypothesis that will allow monitoring the response of the state agencies, through the procedures established by law in the Republic of Chile. Our research delivers results that allow us to affirm that there are areas for hypothetical events that could generate tsunamis in which the To carry out this research we have used a software called STLAT based on simplified equations of the propagation of a tsunami wave, which has allowed us to get quick results. We have also carried out tests with official data which have shown that the alarm system was not able to respond appropriately to the 8.4 M Atico event that occurred in Peru in 2001.

Gabriel, Alvarez; Jorge, Ramirez; Lorena, Paredes; Miguel, Canales.

2010-12-01

250

Tsunami generated by a granular collapse down a rough inclined plane  

CERN Document Server

In this Letter, we experimentally investigate the collapse of initially dry granular media into water and the subsequent impulse waves. We systematically characterize the influence of the slope angle and the granular material on the initial amplitude of the generated leading wave and the evolution of its amplitude during the propagation. The experiments show that whereas the evolution of the leading wave during the propagation is well predicted by a solution of the linearized Korteweg-de Vries equation, the generation of the wave is more complicated to describe. Our results suggest that the internal properties of the granular media and the interplay with the surrounding fluid are important parameters for the generation of waves at low velocity impacts. Moreover, the amplitude of the leading wave reaches a maximum value at large slope angle. The runout distance of the collapse is also shown to be smaller in the presence of water than under totally dry conditions. This study provides a first insight into tsunam...

Viroulet, Sylvain; Kimmoun, Olivier

2014-01-01

251

Presumption of accident progression of Fukushima Dai-ichi and comparison of event sequences among NPSs affected by Tsunami  

International Nuclear Information System (INIS)

In order to contribute to an improvement of accident managements and station blackout countermeasures for NPSs in Japan after the accident of Fukushima Dai-ichi Nuclear Power Stations (NPSs), Japan Nuclear Energy Safety Organization (JNES) has analyzed the progress of the accident scenarios and situation of reactor of the unit 1, 2 and 3 of Fukushima Dai-ichi NPS based on the information such as fragmentary plant chronologies, parameters and information disclosed by TEPCO and tried to figure out the rational explanation of behavior of each plant. In addition, JNES has compared and categorized the event sequences by using event tree method based on the event progression of Fukushima Dai-ichi, Fukushima Dai-ni, Tokai Dai-ni and Onagawa NPSs in order to extract important events and key factors from the viewpoint of prevention of core damage events and impact to event progression. (author)

252

Near-field tsunami simulations of the Great Sumatra earthquake of December 2004  

Science.gov (United States)

The northern tip of Sumatra, and more specifically the Banda Aceh and Lhok-Nga areas, were greatly affected by the Indian Ocean tsunami of December 2004. Following the event, International Tsunami Survey Teams (ITST) carried out several surveys in the area to interview witnesses of the event, and to measure the traces left by the devastating wave: run-up measurements exceeded 20 m in most parts with water reaching up to 5 km inland. We conducted numerical simulations so as to reconstitute the chronology of the event, and to explain the distribution of run-up values. A very high resolution DEM (18 m) of the region, compulsory to accurately model the tsunami interaction with the coast, was built thanks to several field missions of the French-Indonesian TSUNARISQUE consortium. The raw data, which include numerous echo-sounder and DGPS profiles, were merged using the "ordinary kriging" interpolation method. Information provided by satellite imagery before and after the event were also integrated to correct the data from subsidence, and tsunami erosion. We present the results obtained for several relevant slip models, and discuss their ability to reproduce the collected data. These forward models were also used to stress the source parameters determinant for the generation of such high run-up amplitudes. Finally, the detailed description of the ground surface provides a unique opportunity to test the sensitivity of tsunami flow to standard roughness coefficients over long distances.

Sladen, A.; Hébert, H.; Brunstein, D.; Schindelé, F.; Lavigne, F.; Vautier, F.; Paris, R.

2006-12-01

253

How study of hurricane swell can help to provide a better prediction of the tsunami wave propagation on Caribbean coasts?  

Science.gov (United States)

Prediction of tsunami wave propagation on a complex bathymetry can be fatal. Do a mistake on the location of the tsunami wave impact on the coast is highly dangerous. The destruction due to mechanical impact or submersion of the large area of the coast zone can be avoid with a good estimation (i.e.; height, location, duration) of the hazard. Features of the propagation are important in term of values but also in term of dynamic, an evacuation plan is directly base on the prediction of the sequence of events. The frequency of large tsunami is low, but the study of real case may help to have a complete comprehension of the process. We would be better prepare for a tsunami if we had more tsunami. Caribbean arc was generated by an intense tectonic motion and volcanic activity. The risk of tsunami is high in the area both generated by tectonic motion and volcanic landslide. The quality of a numerical propagation of tsunami is highly dependent of the quality of the DEM Caribbean coast are impact by large Hurricane wave. The study of those can be helpful in the tsunami study, particularly for the bathymetry effect on large wave. The shape of the both types of wave are not the same, we do not try to do a direct comparison, but used the information of the dispersion of large swell wave to applied it to the tsunami dispersion and fill the lack of information of the bathymetry. We focus on the comparative study of the propagation of tsunami wave generated by submarine volcano land slide and hurricane wave on a small scale bathymetry (10 m, Lito 3d). The case of Guadeloupe and Martinique island are detailed in this study, due to the available dataset. We used those two territories as reference area. The numerical propagation of the waves is done with FUNWAVE on two different bathymetry (10 m & 50 m). The tsunami wave was generated by VolcFlow in case of submarine volcano collapse and the swell determine by coupling of WaveWatchIII and SWAN in case of past Hurricane. The information gathered by the propagation of a past study will help to correct the bathymetry and have a best prediction of the propagation of a tsunami wave. The result is applied on other Caribbean islands to improve the prediction method of tsunami wave propagation.

Dorville, Jean-François; Dondin, Frédéric; Cécé, Raphael; Bernard, Didier

2014-05-01

254

2011 Tohoku tsunami survey and its historical comparison at Rikuzentakata  

Science.gov (United States)

In the immediate aftermath of the 2011 Tohoku earthquake, we conducted detailed field reconnaissance in the City of Rikuzentakata, Iwate Prefecture, Japan during two time periods of 26-29 March and 9-11 April, 2011. Figure 1 shows a typical panoramic photo taken in our survey. Comparing with three historical tsunami events occurred in this region, i.e., the 1896 Meiji tsunami, the 1933 Showa tsunami and the 1960 Chilean tsunami, the 2011 Tohoku tsunami presents the largest values with respect to the wave height, the flooding area and the inundation distance. Relatively uniform tsunami heights were recorded along the Hirota Bay with a representative tsunami height of 15 m, and an increased wave height of 20 m was documented at rocky cape tips. The inundation area of the 2011 tsunami is even larger than the sum of other three previous events. The 2011 Tohoku tsunami exceeded by almost 2.6 times the area flooded by the 1960 Chilean tsunami, which although ranks second. Quite a few new observations were made during the 2011 Tohoku tsunami attack, e.g., the significant tsunami overland flooding even in the rear side of mountains and the entire transfixion of tsunami inundation area at the base of the Hirota Peninsula. The maximum tsunami inundation distance along the Kesen River of 8.1 km from the river mouth, exceeds by 6.2/2.7 times recorded of the 1933 Showa/1960 Chilean tsunami events. Tsunami inundation height linearly decreases along the Kesen River at a rate of 1 m/km. The tsunami inland flooding distance is less than 2 km in Rikuzentakata urban area. A sophisticated variation on the tsunami inundation and runup heights is observed overland, and the relevant tsunami height gradually amplifies towards the east following the corresponding topography. A 2 km longshore coastal forest, originally supposed to act as an artificial tsunami breakwater to protect the inland communities, completely failed during the 2011 event. At the same time, many designated tsunami shelters, such as the city's indoor sports arena and the ancient temple, were within the tsunami flooding zone and failed to save human lives - a risk that was underestimated at present.

Liu, H.; Shimozono, T.; Takagawa, T.; Okayasu, A.; Fritz, H. M.; Sato, S.; Tajima, Y.

2011-12-01

255

Improved tsunami impact assessments: validation, comparison and the integration of hydrodynamic modeling  

Science.gov (United States)

As communities become increasingly aware of the risks posed by tsunamis, it is important to develop methods for predicting the damage they can cause to the built environment. This will provide the information needed to make informed decisions regarding land-use, building codes, and evacuation. At present, a number of tsunami-building vulnerability assessment models are available, however, the relative infrequency and destructive nature of tsunamis has long made it difficult to obtain the data necessary to adequately validate and compare them. Further complicating matters is that the inundation of a tsunami in the built environment is very difficult model, as is the response of a building to the hydraulic forces that a tsunami generates. Variations in building design and condition will significantly affect a building's susceptibility to damage. Likewise, factors affecting the flow conditions at a building (i.e. surrounding structures and topography), will greatly affect its exposure. This presents significant challenges for practitioners, as they are often left in the dark on how to use hazard modeling and vulnerability assessment techniques together to conduct the community-scale impact studies required for tsunami planning. This paper presents the results of an in-depth case study of Yuriage, Miyagi Prefecture - a coastal city in Japan that was badly damaged by the 2011 Tohoku tsunami. The aim of the study was twofold: 1) To test and compare existing tsunami vulnerability assessment models and 2) To more effectively utilize hydrodynamic models in the context of tsunami impact studies. Following the 2011 Tohoku event, an unprecedented quantity of field data, imagery and video emerged. Yuriage in particular, features a comprehensive set of street level Google Street View imagery, available both before and after the event. This has enabled the collection of a large dataset describing the characteristics of the buildings existing before the event as well the subsequent damage that they sustained during. These data together with the detailed results from hydrodynamic models have been used to provide the building, damage and hazard data necessary to rigorously test and compare existing vulnerability assessments techniques. The result is a much-improved understanding of the capabilities of existing vulnerability assessment techniques, as well as important improvements to their assessment framework This provides much needed guidance to practitioners on how to conduct tsunami impact assessments in the future. Furthermore, the study introduces some new methods of integrating hydrodynamic models into vulnerability assessment models, offering guidance on how to more effectively model tsunami inundation in the built environment.

Tarbotton, C.; Walters, R. A.; Goff, J. R.; Dominey-Howes, D.; Turner, I. L.

2012-12-01

256

Pliocene mass failure deposits mistaken as submarine tsunami backwash sediments - An example from Hornitos, northern Chile  

Science.gov (United States)

In this study we question the former interpretation of a shallow marine backwash tsunami origin of a conspicuous Pliocene coarse clastic unit at Hornitos, northern Chile, and instead argue for a debris flow origin for this unit. We exclude a relation to a tsunami in general and to the Eltanin impact in particular. The observed deposit at Hornitos was not generated either directly (impact-triggered tsunami) or indirectly (submarine mass flow caused by seismic shaking) by an impact. Re-calculation of the alleged impact tsunami including consideration of the Van Dorn effect shows that an impact in the Southern Ocean did not cause a significant tsunami at Hornitos. Impact-related seismic shaking was not able to trigger slides several thousands of kilometers away because the Eltanin event was a deep sea-impact that did not create a crater. Additionally, the biostratigraphic age of 5.1-2.8 Ma of the associated La Portada Formation is not concurrent with the newly established age of 2.511 ± 0.07 Ma for the Eltanin impact. Instead, we argue for an origin of the conspicuous unit at Hornitos as a debris flow deposit caused by an earthquake in the Andean subduction zone in northern Chile. Our re-interpretation considers the local synsedimentary tectonic background, a comparison to recent submarine tsunami sediments, and recent examples of mass wasting deposits along the Chilean margin. The increased uplift during the Pliocene caused oversteepening of the coastal scarp and entailed a contemporaneous higher frequency of seismic events that triggered slope failures and cliff collapses. The coarse clastic unit at Hornitos represents an extraordinary, potentially tsunami-generating mass wasting event that is intercalated with mass wasting deposits on a smaller scale.

Spiske, Michaela; Bahlburg, Heinrich; Weiss, Robert

2014-05-01

257

Large historical earthquakes and tsunamis in a very active tectonic rift: the Gulf of Corinth, Greece  

Science.gov (United States)

The Gulf of Corinth is an active tectonic rift controlled by E-W trending normal faults with an uplifted footwall in the south and a subsiding hangingwall with antithetic faulting in the north. Regional geodetic extension rates up to about 1.5 cm/yr have been measured, which is one of the highest for tectonic rifts in the entire Earth, while seismic slip rates up to about 1 cm/yr were estimated. Large earthquakes with magnitudes, M, up to about 7 were historically documented and instrumentally recorded. In this paper we have compiled historical documentation of earthquake and tsunami events occurring in the Corinth Gulf from the antiquity up to the present. The completeness of the events reported improves with time particularly after the 15th century. The majority of tsunamis were caused by earthquake activity although the aseismic landsliding is a relatively frequent agent for tsunami generation in Corinth Gulf. We focus to better understand the process of tsunami generation from earthquakes. To this aim we have considered the elliptical rupture zones of all the strong (M? 6.0) historical and instrumental earthquakes known in the Corinth Gulf. We have taken into account rupture zones determined by previous authors. However, magnitudes, M, of historical earthquakes were recalculated from a set of empirical relationships between M and seismic intensity established for earthquakes occurring in Greece during the instrumental era of seismicity. For this application the macroseismic field of each one of the earthquakes was identified and seismic intensities were assigned. Another set of empirical relationships M/L and M/W for instrumentally recorded earthquakes in the Mediterranean region was applied to calculate rupture zone dimensions; where L=rupture zone length, W=rupture zone width. The rupture zones positions were decided on the basis of the localities of the highest seismic intensities and co-seismic ground failures, if any, while the orientation of the maximum axis of the ellipse was determined by following the local fault trends. The tsunami size was calculated in terms of tsunami intensity in the 12-point scale of Papadopoulos-Imamura. We investigated empirical correlations between (i) the tsunami intensity and earthquake magnitude, (ii) the frequency of earthquakes and the frequency of tsunamis, as well as (iii) between the maximum tsunami inundation and the position of the earthquake rupture zone. We discuss our results as for their importance for the development of a tsunami decision matrix in the particular area of Corinth Gulf, an issue which is of interest from the point of view of tsunami early warning.

Triantafyllou, Ioanna; Papadopoulos, Gerassimos

2014-05-01

258

General-purpose event generators for LHC physics  

International Nuclear Information System (INIS)

We review the physics basis, main features and use of general-purpose Monte Carlo event generators for the simulation of proton-proton collisions at the Large Hadron Collider. Topics included are: the generation of hard scattering matrix elements for processes of interest, at both leading and next-to-leading QCD perturbative order; their matching to approximate treatments of higher orders based on the showering approximation; the parton and dipole shower formulations; parton distribution functions for event generators; non-perturbative aspects such as soft QCD collisions, the underlying event and diffractive processes; the string and cluster models for hadron formation; the treatment of hadron and tau decays; the inclusion of QED radiation and beyond Standard Model processes. We describe the principal features of the ARIADNE, Herwig++, PYTHIA 8 and SHERPA generators, together with the Rivet and Professor validation and tuning tools, and discuss the physics philosophy behind the proper use of these generators and tools. This review is aimed at phenomenologists wishing to understand better how parton-level predictions are translated into hadron-level events as well as experimentalists seeking a deeper insight into the tools available for signal and background simulation at the LHC.

259

General-purpose event generators for LHC physics  

Energy Technology Data Exchange (ETDEWEB)

We review the physics basis, main features and use of general-purpose Monte Carlo event generators for the simulation of proton-proton collisions at the Large Hadron Collider. Topics included are: the generation of hard-scattering matrix elements for processes of interest, at both leading and next-to-leading QCD perturbative order; their matching to approximate treatments of higher orders based on the showering approximation; the parton and dipole shower formulations; parton distribution functions for event generators; non-perturbative aspects such as soft QCD collisions, the underlying event and diffractive processes; the string and cluster models for hadron formation; the treatment of hadron and tau decays; the inclusion of QED radiation and beyond-Standard-Model processes. We describe the principal features of the Ariadne, Herwig++, Pythia 8 and Sherpa generators, together with the Rivet and Professor validation and tuning tools, and discuss the physics philosophy behind the proper use of these generators and tools. This review is aimed at phenomenologists wishing to understand better how parton-level predictions are translated into hadron-level events as well as experimentalists wanting a deeper insight into the tools available for signal and background simulation at the LHC.

Buckley, Andy; /Edinburgh U.; Butterworth, Jonathan; /University Coll. London; Gieseke, Stefan; /Karlsruhe U., ITP; Grellscheid, David; /Durham U., IPPP; Hoche, Stefan; /SLAC; Hoeth, Hendrik; Krauss, Frank; /Durham U., IPPP; Lonnblad, Leif; /Lund U., Dept. Theor. Phys. /CERN; Nurse, Emily; /University Coll. London; Richardson, Peter; /Durham U., IPPP; Schumann, Steffen; /Heidelberg U.; Seymour, Michael H.; /Manchester U.; Sjostrand, Torbjorn; /Lund U., Dept. Theor. Phys.; Skands, Peter; /CERN; Webber, Bryan; /Cambridge U.

2011-03-03

260

Response of Coastal Structures against Earthquake Forces Considering Soil-Structure Interaction and Tsunami Run-Up Forces  

Directory of Open Access Journals (Sweden)

Full Text Available The catastrophic tsunamis generated by the great Indonesia earthquake triggered on December 26th, 2004, warned the coastal community on preparedness and constructing safe structures to resist against such events. Earthquake occurs suddenly without warning and bulk of destruction takes place within a short period of time. Similarly, when tsunami strikes, there will be a tremendous loss and damage in coastal regions. Apart from having a sound warning system in case of tsunamis, it is necessary to build Earthquake–Tsunami Resistant (ETR shelters, where residents living in coastal plain regions cannot move to farther distances before tsunami arrives the coast. Hence it is necessary to establish analytical methods for obtaining the response of coastal structures subjected to earthquake forces considering soil-structure interaction and also against tsunami run-up forces. A three storied shelter building with four different cases of structural configurations and another typical structure, an elevated water tank of 6 lakh liters capacity are chosen for the analysis. A comparative study is made on the response of these structures against earthquake forces, when they rest on different soil/rock media. In the analysis, IS 1893-2002 seismic code for determining the base shear values against earthquake loads and FEMA 55 to calculate hydrodynamic and impact forces against tsunami impact are used. From the results, it is observed that the refuge shelters that are chosen are more vulnerable to high tide tsunami loads compared to earthquake loads. In general, it is noticed that Base shears and Displacements increase with the decreases in stiffness of the soil and this increase attributes more due to rocking effect of the soil. Buildings with open storey at bottom and upper stories with heavy mass give significant rise to time period of these structures causing early failures during an earthquake before tsunami arrives. In this study, a useful guideline is evaluated demarcating the heights below which earthquake forces and above which tsunami forces are predominant in the structure.

Prof.P.Kodanda Ramarao,

2013-06-01

 
 
 
 
261

The 1945 Balochistan earthquake and probabilistic tsunami hazard assessment for the Makran subduction zone  

Science.gov (United States)

Iran and Pakistan are countries quite frequently affected by destructive earthquakes. For instance, the magnitude 6.6 Bam earthquake in 2003 in Iran with about 30'000 casualties, or the magnitude 7.6 Kashmir earthquake 2005 in Pakistan with about 80'000 casualties. Both events took place inland, but in terms of magnitude, even significantly larger events can be expected to happen offshore, at the Makran subduction zone. This small subduction zone is seismically rather quiescent, but a tsunami caused by a thrust event in 1945 (Balochistan earthquake) led to about 4000 casualties. Nowadays, the coastal regions are more densely populated and vulnerable to similar events. Additionally, some recent publications raise the question of the possiblity of rare but huge magnitude 9 events at the Makran subduction zone. We first model the historic Balochistan event and its effect in terms of coastal wave heights, and then generate various synthetic earthquake and tsunami catalogs including the possibility of large events in order to asses the tsunami hazard at the affected coastal regions. Finally, we show how an effective tsunami early warning could be achieved by the use of an array of high-precision real-time GNSS (Global Navigation Satellite System) receivers along the coast.

Höchner, Andreas; Babeyko, Andrey; Zamora, Natalia

2014-05-01

262

Absolute GPS Time Event Generation and Capture for Remote Locations  

Science.gov (United States)

The HiRes experiment operates fixed location and portable lasers at remote desert locations to generate calibration events. One physics goal of HiRes is to search for unusual showers. These may appear similar to upward or horizontally pointing laser tracks used for atmospheric calibration. It is therefore necessary to remove all of these calibration events from the HiRes detector data stream in a physics blind manner. A robust and convenient "tagging" method is to generate the calibration events at precisely known times. To facilitate this tagging method we have developed the GPSY (Global Positioning System YAG) module. It uses a GPS receiver, an embedded processor and additional timing logic to generate laser triggers at arbitrary programmed times and frequencies with better than 100nS accuracy. The GPSY module has two trigger outputs (one microsecond resolution) to trigger the laser flash-lamp and Q-switch and one event capture input (25nS resolution). The GPSY module can be programmed either by a front panel menu based interface or by a host computer via an RS232 serial interface. The latter also allows for computer logging of generated and captured event times. Details of the design and the implementation of these devices will be presented. 1 Motivation Air Showers represent a small fraction, much less than a percent, of the total High Resolution Fly's Eye data sample. The bulk of the sample is calibration data. Most of this calibration data is generated by two types of systems that use lasers. One type sends light directly to the detectors via optical fibers to monitor detector gains (Girard 2001). The other sends a beam of light into the sky and the scattered light that reaches the detectors is used to monitor atmospheric effects (Wiencke 1998). It is important that these calibration events be cleanly separated from the rest of the sample both to provide a complete set of monitoring information, and more

HIRES Collaboration

263

Global Quick Scan of the Vulnerability of Groundwater systems to Tsunamis  

Science.gov (United States)

Fresh groundwater resources in deltaic areas are used for domestic, agricultural and industrial purposes. These resources in the coastal zone are threatened by salinization of the aquifers due to global change (increase of groundwater extraction due to population growth), climate change (including sea level rise), as well as natural disasters such as floods and tsunamis. Studies of how the coastal fresh groundwater resources are affected by the latter phenomena are often done a posteriori, especially the studies related to tsunami effects (e.g. the 2003 Sumatra Tsunami). Then it is often too late to take appropriated measures to counteract the negative effects (e.g. on drinking water supply). These complex studies are time consuming, and need data which might not be available at the time of the disaster when a fast reaction of the water authorities is needed, e.g. to facilitate a quick and easy to access fresh water supply system. In our study we present a Global Quick Scan of the vulnerability of the deltaic fresh groundwater resources to tsunamis. We created a global database including the data needed to generate fast and simple models on the salinization of groundwater systems in the coastal zone. These quantifications give water manager a first approximation of the effects that a tsunami would have on the salinization of the fresh groundwater. The data collected in this database has been used to generate a map showing the areas with coastal groundwater systems vulnerable to tsunami effects, as well as a dataset of 500 2D models representing the physical characteristics of the most frequent coastal groundwater systems in tsunami vulnerable areas. These 2D models simulate the loss in fresh groundwater volume of the system and the characteristic time of a system before it recovers 90% of the fresh groundwater that was available previous to the tsunami event. A similar approach could be adopted for assessing the effect of sea level rise and future increased groundwater extractions on vulnerable coastal groundwater systems worldwide.

Oude Essink, Gualbert; Faneca Sànchez, Marta; Zamrsky, Daniel

2014-05-01

264

Sensor-Generated Time Series Events: A Definition Language  

Directory of Open Access Journals (Sweden)

Full Text Available There are now a great many domains where information is recorded by sensors over a limited time period or on a permanent basis. This data flow leads to sequences of data known as time series. In many domains, like seismography or medicine, time series analysis focuses on particular regions of interest, known as events, whereas the remainder of the time series contains hardly any useful information. In these domains, there is a need for mechanisms to identify and locate such events. In this paper, we propose an events definition language that is general enough to be used to easily and naturally define events in time series recorded by sensors in any domain. The proposed language has been applied to the definition of time series events generated within the branch of medicine dealing with balance-related functions in human beings. A device, called posturograph, is used to study balance-related functions. The platform has four sensors that record the pressure intensity being exerted on the platform, generating four interrelated time series. As opposed to the existing ad hoc proposals, the results confirm that the proposed language is valid, that is generally applicable and accurate, for identifying the events contained in the time series.

Juan Pazos

2012-08-01

265

The elementary events underlying force generation in neuronal lamellipodia.  

Science.gov (United States)

We have used optical tweezers to identify the elementary events underlying force generation in neuronal lamellipodia. When an optically trapped bead seals on the lamellipodium membrane, Brownian fluctuations decrease revealing the underlying elementary events. The distribution of bead velocities has long tails with frequent large positive and negative values associated to forward and backward jumps occurring in 0.1-0.2 ms with varying amplitudes up to 20 nm. Jump frequency and amplitude are reduced when actin turnover is slowed down by the addition of 25 nM Jasplakinolide. When myosin II is inhibited by the addition of 20 ?M Blebbistatin, jump frequency is reduced but to a lesser extent than by Jasplainolide. These jumps constitute the elementary events underlying force generation. PMID:22355669

Amin, Ladan; Ercolini, Erika; Shahapure, Rajesh; Bisson, Giacomo; Torre, Vincent

2011-01-01

266

Monte Carlo event generators for hadron-hadron collisions  

Energy Technology Data Exchange (ETDEWEB)

A brief review of Monte Carlo event generators for simulating hadron-hadron collisions is presented. Particular emphasis is placed on comparisons of the approaches used to describe physics elements and identifying their relative merits and weaknesses. This review summarizes a more detailed report.

Knowles, I.G. [Argonne National Lab., IL (United States). High Energy Physics Div.; Protopopescu, S.D. [Brookhaven National Lab., Upton, NY (United States)

1993-06-01

267

Tsunami lung.  

Science.gov (United States)

We encountered three cases of lung disorders caused by drowning in the recent large tsunami that struck following the Great East Japan Earthquake. All three were females, and two of them were old elderly. All segments of both lungs were involved in all the three patients, necessitating ICU admission and endotracheal intubation and mechanical ventilation. All three died within 3 weeks. In at least two cases, misswallowing of oil was suspected from the features noted at the time of the detection. Sputum culture for bacteria yielded isolation of Stenotrophomonas maltophilia, Legionella pneumophila, Burkholderia cepacia, and Pseudomonas aeruginosa. The cause of tsunami lung may be a combination of chemical induced pneumonia and bacterial pneumonia. PMID:22057370

Inoue, Yoshihiro; Fujino, Yasuhisa; Onodera, Makoto; Kikuchi, Satoshi; Shozushima, Tatsuyori; Ogino, Nobuyoshi; Mori, Kiyoshi; Oikawa, Hirotaka; Koeda, Yorihiko; Ueda, Hironobu; Takahashi, Tomohiro; Terui, Katsutoshi; Nakadate, Toshihide; Aoki, Hidehiko; Endo, Shigeatsu

2012-04-01

268

Grey-box GUI Testing: Efficient Generation of Event Sequences  

CERN Document Server

Graphical user interfaces (GUIs), due to their event driven nature, present a potentially unbounded space of all possible ways to interact with software. During testing it becomes necessary to effectively sample this space. In this paper we develop algorithms that sample the GUI's input space by only generating sequences that (1) are allowed by the GUI's structure, and (2) chain together only those events that have data dependencies between their event handlers. We create a new abstraction, called an event-dependency graph (EDG) of the GUI, that captures data dependencies between event handler code. We develop a mapping between EDGs and an existing black-box user-level model of the GUI's workflow, called an event-flow graph (EFG). We have implemented automated EDG construction in a tool that analyzes the bytecode of each event handler. We evaluate our "grey-box" approach using four open-source applications and compare it with the current state-of-the-art EFG approach. Our results show that using the EDG reduc...

Arlt, Stephan; Bertolini, Cristiano; Memon, Atif M; Schäf, Martin

2012-01-01

269

Validation of NEOWAVE with Measurements from the 2011 Tohoku Tsunami  

Science.gov (United States)

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.

Cheung, K.; Yamazaki, Y.

2012-12-01

270

Simulation of space-borne tsunami detection using GNSS-Reflectometry applied to tsunamis in the Indian Ocean  

Directory of Open Access Journals (Sweden)

Full Text Available Within the German-Indonesian Tsunami Early Warning System project GITEWS (Rudloff et al., 2009, a feasibility study on a future tsunami detection system from space has been carried out. The Global Navigation Satellite System Reflectometry (GNSS-R is an innovative way of using reflected GNSS signals for remote sensing, e.g. sea surface altimetry. In contrast to conventional satellite radar altimetry, multiple height measurements within a wide field of view can be made simultaneously. With a dedicated Low Earth Orbit (LEO constellation of satellites equipped with GNSS-R, densely spaced sea surface height measurements could be established to detect tsunamis. This simulation study compares the Walker and the meshed comb constellation with respect to their global reflection point distribution. The detection performance of various LEO constellation scenarios with GPS, GLONASS and Galileo as signal sources is investigated. The study concentrates on the detection performance for six historic tsunami events in the Indian Ocean generated by earthquakes of different magnitudes, as well as on different constellation types and orbit parameters. The GNSS-R carrier phase is compared with the PARIS or code altimetry approach. The study shows that Walker constellations have a much better reflection point distribution compared to the meshed comb constellation. Considering simulation assumptions and assuming technical feasibility it can be demonstrated that strong tsunamis with magnitudes (M ?8.5 can be detected with certainty from any orbit altitude within 15–25 min by a 48/8 or 81/9 Walker constellation if tsunami waves of 20 cm or higher can be detected by space-borne GNSS-R. The carrier phase approach outperforms the PARIS altimetry approach especially at low orbit altitudes and for a low number of LEO satellites.

R. Stosius

2010-06-01

271

Simulation of space-borne tsunami detection using GNSS-Reflectometry applied to tsunamis in the Indian Ocean  

Science.gov (United States)

Within the German-Indonesian Tsunami Early Warning System project GITEWS (Rudloff et al., 2009), a feasibility study on a future tsunami detection system from space has been carried out. The Global Navigation Satellite System Reflectometry (GNSS-R) is an innovative way of using reflected GNSS signals for remote sensing, e.g. sea surface altimetry. In contrast to conventional satellite radar altimetry, multiple height measurements within a wide field of view can be made simultaneously. With a dedicated Low Earth Orbit (LEO) constellation of satellites equipped with GNSS-R, densely spaced sea surface height measurements could be established to detect tsunamis. This simulation study compares the Walker and the meshed comb constellation with respect to their global reflection point distribution. The detection performance of various LEO constellation scenarios with GPS, GLONASS and Galileo as signal sources is investigated. The study concentrates on the detection performance for six historic tsunami events in the Indian Ocean generated by earthquakes of different magnitudes, as well as on different constellation types and orbit parameters. The GNSS-R carrier phase is compared with the PARIS or code altimetry approach. The study shows that Walker constellations have a much better reflection point distribution compared to the meshed comb constellation. Considering simulation assumptions and assuming technical feasibility it can be demonstrated that strong tsunamis with magnitudes (M) ?8.5 can be detected with certainty from any orbit altitude within 15-25 min by a 48/8 or 81/9 Walker constellation if tsunami waves of 20 cm or higher can be detected by space-borne GNSS-R. The carrier phase approach outperforms the PARIS altimetry approach especially at low orbit altitudes and for a low number of LEO satellites.

Stosius, R.; Beyerle, G.; Helm, A.; Hoechner, A.; Wickert, J.

2010-06-01

272

The 25 October 2010 Sumatra tsunami earthquake: Slip in a slow patch  

Science.gov (United States)

Various models for the generation of tsunami earthquakes have been proposed, including shallow earthquake slip through low strength materials. Because these physical fault conditions would likely affect other earthquakes in the same rupture zone, source properties of other events may provide a guide to locations of tsunami earthquakes. The 25 October 2010 Mw = 7.8 Mentawai tsunami earthquake and surrounding events provide a test of this hypothesis. We determine slip patterns for the mainshock and relocate aftershocks, with the majority occurring in the near trench region. The two largest magnitude aftershocks occurred within the downdip end of the mainshock rupture area and have long moment-normalized rupture duration, likely related to fault zone conditions. Several older relocated earthquakes at the northern edge of the 2010 rupture area also have long duration character, suggesting both spatial and temporal consistency in the conditions needed to produce slow seismic processes along this margin.

Bilek, Susan L.; Engdahl, E. Robert; DeShon, Heather R.; El Hariri, Maya

2011-07-01

273

Tsunami Source of the 2010 Mentawai, Indonesia Earthquake Inferred from Tsunami Field Survey and Waveform Modeling  

Science.gov (United States)

The 2010 Mentawai earthquake (magnitude 7.7) generated a destructive tsunami that caused more than 500 casualties in the Mentawai Islands, west of Sumatra, Indonesia. Seismological analyses indicate that this earthquake was an unusual "tsunami earthquake," which produces much larger tsunamis than expected from the seismic magnitude. We carried out a field survey to measure tsunami heights and inundation distances, an inversion of tsunami waveforms to estimate the slip distribution on the fault, and inundation modeling to compare the measured and simulated tsunami heights. The measured tsunami heights at eight locations on the west coasts of North and South Pagai Island ranged from 2.5 to 9.3 m, but were mostly in the 4-7 m range. At three villages, the tsunami inundation extended more than 300 m. Interviews of local residents indicated that the earthquake ground shaking was less intense than during previous large earthquakes and did not cause any damage. Inversion of tsunami waveforms recorded at nine coastal tide gauges, a nearby GPS buoy, and a DART station indicated a large slip (maximum 6.1 m) on a shallower part of the fault near the trench axis, a distribution similar to other tsunami earthquakes. The total seismic moment estimated from tsunami waveform inversion was 1.0 × 1021 Nm, which corresponded to Mw 7.9. Computed coastal tsunami heights from this tsunami source model using linear equations are similar to the measured tsunami heights. The inundation heights computed by using detailed bathymetry and topography data and nonlinear equations including inundation were smaller than the measured ones. This may have been partly due to the limited resolution and accuracy of publically available bathymetry and topography data. One-dimensional run-up computations using our surveyed topography profiles showed that the computed heights were roughly similar to the measured ones.

Satake, Kenji; Nishimura, Yuichi; Putra, Purna Sulastya; Gusman, Aditya Riadi; Sunendar, Haris; Fujii, Yushiro; Tanioka, Yuichiro; Latief, Hamzah; Yulianto, Eko

2013-09-01

274

Tsunami Catalogues for the Eastern Mediterranean - Revisited.  

Science.gov (United States)

We critically examine examine tsunami catalogues of tsunamis in the Eastern Mediterranean published in the last decade, by reference to the original sources, see Ambraseys (2008). Such catalogues have been widely used in the aftermath of the 2004 Boxing Day tsunami for probabilistic hazard analysis, even to make projections for a ten year time frame. On occasion, such predictions have caused panic and have reduced the credibility of the scientific community in making hazard assessments. We correct classification and other spurious errors in earlier catalogues and posit a new list. We conclude that for some historic events, any assignment of magnitude, even on a six point intensity scale is inappropriate due to lack of information. Further we assert that any tsunami catalogue, including ours, can only be used in conjunction with sedimentologic evidence to quantitatively infer the return period of larger events. Statistical analyses correlating numbers of tsunami events derived solely from catalogues with their inferred or imagined intensities are meaningless, at least when focusing on specific locales where only a handful of tsunamis are known to have been historically reported. Quantitative hazard assessments based on scenario events of historic tsunamis for which -at best- only the size and approximate location of the parent earthquake is known should be undertaken with extreme caution and only with benefit of geologic studies to enhance the understanding of the local tectonics. Ambraseys N. (2008) Earthquakes in the Eastern Mediterranean and the Middle East: multidisciplinary study of 2000 years of seimicity, Cambridge Univ. Press, Cambridge (ISBN 9780521872928).

Ambraseys, N.; Synolakis, C. E.

2008-12-01

275

Modeling propagation and inundation of the 11 March 2011 Tohoku tsunami  

Directory of Open Access Journals (Sweden)

Full Text Available On 11 March 2011 the Tohoku tsunami devastated the east coast of Japan, claiming thousands of casualties and destroying coastal settlements and infrastructure. In this paper tsunami generation, propagation, and inundation are modeled to hindcast the event. Earthquake source models with heterogeneous slips are developed in order to match tsunami observations, including a best fit initial sea surface elevation with water levels up to 8 m. Tsunami simulations were compared to buoys in the Pacific, showing good agreement. In the far field the frequency dispersion provided a significant reduction even for the leading wave. Furthermore, inundation simulations were performed for ten different study areas. The results compared well with run-up measurements available and trim lines derived from satellite images, but with some overestimation of the modeled surface elevation in the northern part of the Sanriku coast. For inundation modeling this work aimed at using freely available, medium-resolution data for topography, bottom friction, and bathymetry, which are easily accessible in the framework of a rapid assessment. Although these data come along with some inaccuracies, the results of the tsunami simulations suggest that their use is feasible for application in rapid tsunami hazard assessments. A heterogeneous source model is essential to simulate the observed distribution of the run-up correctly, though.

F. Løvholt

2012-04-01

276

Assessment of tsunami hazards for the Central American Pacific coast from southern Mexico to northern Peru  

Science.gov (United States)

Central America (CA), from Guatemala to Panama, has been struck by at least 52 tsunamis between 1539 and 2013, and in the extended region from Mexico to northern Peru (denoted as ECA, Extended Central America in this paper) the number of recorded tsunamis in the same time span is more than 100, most of which were triggered by earthquakes located in the Middle American Trench that runs parallel to the Pacific coast. The most severe event in the catalogue is the tsunami that occurred on 2 September 1992 off Nicaragua, with run-up measured in the range of 5-10 m in several places along the Nicaraguan coast. The aim of this paper is to assess the tsunami hazard on the Pacific coast of this extended region, and to this purpose a hybrid probabilistic-deterministic analysis is performed, that is adequate for tsunamis generated by earthquakes. More specifically, the probabilistic approach is used to compute the Gutenberg-Richter coefficients of the main seismic tsunamigenic zones of the area and to estimate the annual rate of occurrence of tsunamigenic earthquakes and their corresponding return period. The output of the probabilistic part of the method is taken as input by the deterministic part, which is applied to calculate the tsunami run-up distribution along the coast.

Brizuela, B.; Armigliato, A.; Tinti, S.

2014-07-01

277

Maize transformation technology development for commercial event generation  

Science.gov (United States)

Maize is an important food and feed crop in many countries. It is also one of the most important target crops for the application of biotechnology. Currently, there are more biotech traits available on the market in maize than in any other crop. Generation of transgenic events is a crucial step in the development of biotech traits. For commercial applications, a high throughput transformation system producing a large number of high quality events in an elite genetic background is highly desirable. There has been tremendous progress in Agrobacterium-mediated maize transformation since the publication of the Ishida et al. (1996) paper and the technology has been widely adopted for transgenic event production by many labs around the world. We will review general efforts in establishing efficient maize transformation technologies useful for transgenic event production in trait research and development. The review will also discuss transformation systems used for generating commercial maize trait events currently on the market. As the number of traits is increasing steadily and two or more modes of action are used to control key pests, new tools are needed to efficiently transform vectors containing multiple trait genes. We will review general guidelines for assembling binary vectors for commercial transformation. Approaches to increase transformation efficiency and gene expression of large gene stack vectors will be discussed. Finally, recent studies of targeted genome modification and transgene insertion using different site-directed nuclease technologies will be reviewed. PMID:25140170

Que, Qiudeng; Elumalai, Sivamani; Li, Xianggan; Zhong, Heng; Nalapalli, Samson; Schweiner, Michael; Fei, Xiaoyin; Nuccio, Michael; Kelliher, Timothy; Gu, Weining; Chen, Zhongying; Chilton, Mary-Dell M.

2014-01-01

278

NLO event generation for chargino production at the ILC  

International Nuclear Information System (INIS)

In the chargino and neutralino sector of the MSSM, the electroweak SUSY parameters can be determined by a small number of measurements of masses and cross sections. At the ILC, these parameters can be determined with an experimental accuracy matching the precision of NLO and higher-order theoretical predictions. The higher order contributions therefore need to be included in the analysis of the parameters of the SUSY sector. We present a NLO Monte-Carlo event generator for simulating chargino pair-production at the ILC. We consider two approaches of including photon radiation. A strict fixed-order approach allows for comparison and consistency checks with published semianalytic results in the literature, but suffers from negative weights in certain points of phase space. A version with soft- and hard-collinear resummation of photon radiation, which combines photon resummation with the inclusion of the NLO matrix element for the production process, avoids negative event weights, so the program can simulate physical (unweighted) event samples. Photons are explicitly generated throughout the range where they can be experimentally resolved. We evaluate the systematic errors due to soft and collinear approximations. In the resummation approach, the residual uncertainty can be brought down to the per-mil level, coinciding with the expected statistical uncertainty at the ILC. We show results for cross sections and event generation for both approaches. (orig.)

279

NLO event generation for chargino production at the ILC  

International Nuclear Information System (INIS)

In the chargino and neutralino sector of the MSSM, the electroweak SUSY parameters can be determined by a small number of measurements of masses and cross sections. At the ILC, these parameters can be determined with an experimental accuracy matching the precision of NLO and higher-order theoretical predictions. The higher order contributions therefore need to be included in the analysis of the parameters of the SUSY sector. We present a NLO Monte-Carlo event generator for simulating chargino pair-production at the ILC. We consider two approaches of including photon radiation. A strict fixed-order approach allows for comparison and consistency checks with published semi analytic results in the literature, but suffers from negative weights in certain points of phase space. A version with soft- and hard-collinear resummation of photon radiation, which combines photon resummation with the inclusion of the NLO matrix element for the production process,avoids negative event weights, so the program can simulate physical (unweighted) event samples. Photons are explicitly generated throughout the range where they can be experimentally resolved. We evaluate the systematic errors due to soft and collinear approximations. In the resummation approach, the residual uncertainty can be brought down to the per-mil level, coinciding with the expected statistical uncertainty at the ILC. We show results for cross sections and event generation for both approaches. (author)

280

National Geophysical Data Center Tsunami Data Archive  

Science.gov (United States)

NOAA's National Geophysical Data Center (NGDC) and co-located World Data Center for Geophysics and Marine Geology long-term tsunami data archive provides data and derived products essential for tsunami hazard assessment, forecast and warning, inundation modeling, preparedness, mitigation, education, and research. As a result of NOAA's efforts to strengthen its tsunami activities, the long-term tsunami data archive has grown from less than 5 gigabyte in 2004 to more than 2 terabytes in 2008. The types of data archived for tsunami research and operation activities have also expanded in fulfillment of the P.L. 109-424. The archive now consists of: global historical tsunami, significant earthquake and significant volcanic eruptions database; global tsunami deposits and proxies database; reference database; damage photos; coastal water-level data (i.e. digital tide gauge data and marigrams on microfiche); bottom pressure recorder (BPR) data as collected by Deep-ocean Assessment and Reporting of Tsunamis (DART) buoys. The tsunami data archive comes from a wide variety of data providers and sources. These include the NOAA Tsunami Warning Centers, NOAA National Data Buoy Center, NOAA National Ocean Service, IOC/NOAA International Tsunami Information Center, NOAA Pacific Marine Environmental Laboratory, U.S. Geological Survey, tsunami catalogs, reconnaissance reports, journal articles, newspaper articles, internet web pages, and email. NGDC has been active in the management of some of these data for more than 50 years while other data management efforts are more recent. These data are openly available, either directly on-line or by contacting NGDC. All of the NGDC tsunami and related databases are stored in a relational database management system. These data are accessible over the Web as tables, reports, and interactive maps. The maps provide integrated web-based GIS access to individual GIS layers including tsunami sources, tsunami effects, significant earthquakes, significant volcano events, and various spatial reference layers such as topography, population density, and political boundaries. The map service also provides ftp links and hyperlinks to additional hazards information such as the NGDC collection of hazards photos. The NGDC website also provides a Keyhole Markup Language (KML) file, updated nightly, containing tsunami sources and runups

Stroker, K. J.; Dunbar, P. K.; Brocko, R.

2008-12-01

 
 
 
 
281

Using GPS to Detect Imminent Tsunamis  

Science.gov (United States)

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

Song, Y. Tony

2009-01-01

282

Inundation Modeling for Probabilistic Tsunami Hazard Assessment  

Science.gov (United States)

Developing quantitative estimates for site-specific tsunami hazard assessments require substantial modeling efforts to simulate potential tsunami impacts. For most locations, the use of historical data alone is not sufficient to derive long- and short-term hazard estimates. Such studies demand additional model data to fill in the gaps in the historical records. Even if a wealth of historical data is available, extra modeling estimates are warranted to account for changes of coastal infrastructure and/or for probable but non-historical events. The goals of numerical modeling for such studies differ substantially from the goals of a typical hindcast simulation, where the model results are compared with various field data for a specific historical event. In probabilistic modeling, comparison with historical data is only the first preliminary step of the study, to ensure reliability of multiple model estimates for probable events. In this respect, the probabilistic simulations are similar to forecast modeling, which employs a similar methodology for model use. We present the methodology and preliminary results of the modeling study of Seaside, Oregon to produce a model database for probabilistic tsunami hazard assessment. Multiple simulations have been performed for a large number of potential far- and near-field tsunami sources using the MOST numerical model. Unlike previous tsunami probabilistic studies, high-resolution numerical grids are employed to resolve details and internal structure of the computed flood zones for each modeled event. Although Seaside does not have a tide gage to record historical tsunamis, some historical tsunami inundation data is available in the form of inundation zone estimates and tsunami sediment data for a limited number of historical events. The numerical model was tested against available historical tsunami measurements. Full numerical solutions for the high-resolution grid are retained for each model run to form a model database that can be used to perform various analyses and probabilistic estimates.

Titov, V. V.; Arcas, D.; Kanoglu, U.; Newman, J.; Gonzalez, F. I.

2004-12-01

283

COMMENT ON: TSUNAMIS AND TSUNAMI-LIKE WAVES OF THE EASTERN UNITED STATES BY PATRICIA A. LOCKRIDGE, LOWELL S. WHITESIDE AND JAMES F. LANDER WITH RESPECT TO THE NOVEMBER 18, 1929 EARTHQUAKE AND ITS TSUNAMI  

Directory of Open Access Journals (Sweden)

Full Text Available This most valuable compilation by Patricia Lockridge et al. (2002 covers a wide range of tsunamis and tsunami-like events ranging from marine tectonic, volcanic, and landslide tsunamis to possible meteorologic tsunami-like events. Lockridge et al.'s (2002 massive text table (pp. 124-141 entitled "Description of Events" covers events from 1668 to 1992. The 2002 paper in Science of Tsunami Hazards was clearly intended to be an update of, an extension to, and a sequel to, the first east coast and Caribbean tsunami compilations contained in Lander and Lockridge's 1989 National Geophysical Data Center volume United States Tsunamis (including United States Possessions 1690-1988.The Lockridge et al. (2002 compilation contains a small error with respect to the 1929 "Grand Banks" Earthquake and Tsunami of which I may be cause in part. In addition the tsunami histories of oceans without a tsunami warning system will be now receiving much closer attention, including historic events in the Atlantic Ocean given the events of December 26, 2004 and March 18, 2005 in the Indian Ocean; both the Atlantic and the Indian Oceans have no tsunami warning system and have an incomplete tsunami history.

Alan Ruffman

2005-01-01

284

Assessing historical rate changes in global tsunami occurrence  

Science.gov (United States)

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

Geist, Eric L.; Parsons, Tom

2011-10-01

285

Assessing historical rate changes in global tsunami occurrence  

Science.gov (United States)

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

Geist, E. L.; Parsons, T.

2011-01-01

286

Heavy ion event generator HYDJET++ (HYDrodynamics plus JETs)  

CERN Document Server

HYDJET++ is a Monte-Carlo event generator for the simulation of relativistic heavy ion AA collisions considered as a superposition of the soft, hydro-type state and the hard, multi-parton state. This model is the development and continuation of HYDJET event generator (Lokhtin & Snigirev, 2006, EPJC, 45, 211). The main program is written in the object-oriented C++ language under the ROOT environment. The hard part of HYDJET++ is identical to the hard part of Fortran-written HYDJET and is included in the generator structure as a separate directory. The soft part of HYDJET++ event is the "thermal" hadronic state generated on the chemical and thermal freeze-out hypersurfaces represented by the parameterization of relativistic hydrodynamics with preset freeze-out conditions. It includes longitudinal, radial and elliptic flow effects and decays of hadronic resonances. The corresponding fast Monte-Carlo simulation procedure, C++ code FAST MC (Amelin et al., 2006, PRC, 74, 064901; 2008, PRC, 77, 014903) is adapte...

Lokhtin, I P; Petrushanko, S V; Snigirev, A M; Arsene, I; Tywoniuk, K

2008-01-01

287

Introduction to "Historical and Recent Catastrophic Tsunamis in the World: Volume II. Tsunamis from 1755 to 2010"  

Science.gov (United States)

Eighteen papers on past and recent destructive tsunamis are included in Volume II of the PAGEOPH topical issue "Historical and Recent Catastrophic Tsunamis in the World." Three papers discuss deep-sea (DART) and coastal tsunami observations, warning systems and risk management in the Pacific Ocean. Four papers examine the 1755 Lisbon, 1964 Alaska, 2003 Algeria, and 2011 Haiti tsunamis. Four more papers, as well as some papers in Volume I, report on various aspects of the 2010 Chile tsunami. Two papers present some results of field survey and modelling investigation of the 2010 Mentawai, Indonesia, tsunami. Three papers report on modelling efforts of tsunami generation by earthquake and landslide, and of tsunami propagation. Finally, two papers discuss hazard assessment using a probabilistic approach.

Satake, Kenji; Rabinovich, Alexander B.; Dominey-Howes, Dale; Borrero, José C.

2013-09-01

288

A Robust Tsunami Deposit Database For California  

Science.gov (United States)

The California Geological Survey (CGS) has partnered with Humboldt State University (HSU) to produce a robust statewide tsunami deposit database to facilitate the evaluation of tsunami hazard products for both emergency response and land-use planning and development. The California tsunami deposit database attributes compliment and expand on existing tsunami deposit databases from the National Geophysical Data Center (NGDC) (Global), the USGS (Cascadia Subduction Zone), and the Oregon Department of Geology and Mineral Industries (DOGAMI) (adjacent state). Whereas the existing NGDC and USGS databases focus on references or individual tsunami layers, this new State-maintained database concentrates on the location and contents of individual cores/trenches that sample tsunami deposits, including laboratory tests to evaluate sample grain-size, geochemistry, microfossils, and age-dating results. The first generation of the database is completed and includes 94 cores from six studies in northern California, at the southern end of the Cascadia Subduction Zone. A second generation of the database will include recently collected tsunami deposit information for the rest of California. 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 tsunami deposits can be more easily evaluated on a regional basis, a recommendation of the National Tsunami Hazard Mitigation Program. This database is being used to help CGS in the development and validation of updates to their existing inundation maps for emergency planning, and probabilistic tsunami hazard analyses (PTHA) of value to local land-use planning and coastal development.

Wilson, R. I.; Hemphill-Haley, E.; Admire, A. R.

2012-12-01

289

Advanced Planning for Tsunamis in California  

Science.gov (United States)

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

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

2013-12-01

290

NiMax system for hadronic event generators in HEP  

International Nuclear Information System (INIS)

We have suggested a new approach to the development and use of Monte Carlo event generators in high-energy physics (HEP). It is a component approach, when a complex numerical model is composed of standard components. Our approach opens a way to organize a library of HEP model components and provides a great flexibility for the construction of very powerful and realistic numerical models. To support this approach we have designed the NiMax software system (framework) written in C++

291

Neutrino-Argon Interaction with GENIE Event Generator  

Science.gov (United States)

Neutrinos are very special particles, have only weak interactions, except gravity, and are produced in very different processes in Nuclear and Particle Physics. Neutrinos are, also, messengers from astrophysical objects, as well as relics from Early Universe. Therefore, its can give us information on processes happening in the Universe, during its evolution, which cannot be studied otherwise. The underground instrumentation including a variety of large and very large detectors, thanks to technical breakthroughs, have achieved new fundamental results like the solution of the solar neutrino puzzle and the evidence for Physics beyond the Standard Model of elementary interactions in the neutrino sector with non-vanishing neutrino masses and lepton flavour violation. Two of the LAGUNA (Large Apparatus studying Grand Unification and Neutrino Astrophysics) detectors, namely: GLACIER (Giant Liquid Argon Charge Imaging ExpeRiment) [1] and LENA (Low Energy Neutrino Astrophysics) [2] could be emplaced in ``Unirea'' salt mine from Sl?nic-Prahova, Romania. A detailed analysis of the conditions and advantages is necessary. A few results have been presented previously [3]. In the present work, we propose to generate events and compute the cross sections for interactions between neutrino and Argon-40, to estimate possible detection performances and event types. For doing this, we use the code GENIE (G_enerates E_vents for N_eutrino I_nteraction E_xperiments) [4]. GENIE Code is an Object-Oriented Neutrino MC Generator supported and developed by an international collaboration of neutrino interaction experts.

Chesneanu, Daniela

2010-11-01

292

Simulation of multiple Steam Generator Tube Rupture (SGTR) event scenario  

International Nuclear Information System (INIS)

The multiple Steam Generator Tube Rupture (SGTR) event scenario with available safety systems was experimentally and analytically evaluated. The experiment was conducted on the large scaled test facility to simulate the multiple SGTR event and investigate the effectiveness of operator actions. As a result, it indicated that the opening of pressurizer power operated relief valve was significantly effective in quickly terminating the primary-to-secondary break flow even for the 6.5 tubes rupture. In the analysis, the recent version of RELAP5 code was assessed with the test data. It indicated that the calculations agreed well with the measured data and that the plant responses such as the water level and relief valve cycling in the damaged steam generator were reasonably predicted. Finally, sensitivity study on the number of ruptured tubes up to 10 tubes was performed to investigate the coolant release into atmosphere. It indicated that the integrated steam mass released was not significantly varied with the number of ruptured tubes although the damaged steam generator was overfilled for more than 3 tubes rupture. These findings are expected to provide useful information in understanding and evaluating the plant ability to mitigate the consequence of multiple SGTR event

293

Simulation of multiple Steam Generator Tube Rupture (SGTR) event scenario  

Energy Technology Data Exchange (ETDEWEB)

The multiple Steam Generator Tube Rupture (SGTR) event scenario with available safety systems was experimentally and analytically evaluated. The experiment was conducted on the large scaled test facility to simulate the multiple SGTR event and investigate the effectiveness of operator actions. As a result, it indicated that the opening of pressurizer power operated relief valve was significantly effective in quickly terminating the primary-to-secondary break flow even for the 6.5 tubes rupture. In the analysis, the recent version of RELAP5 code was assessed with the test data. It indicated that the calculations agreed well with the measured data and that the plant responses such as the water level and relief valve cycling in the damaged steam generator were reasonably predicted. Finally, sensitivity study on the number of ruptured tubes up to 10 tubes was performed to investigate the coolant release into atmosphere. It indicated that the integrated steam mass released was not significantly varied with the number of ruptured tubes although the damaged steam generator was overfilled for more than 3 tubes rupture. These findings are expected to provide useful information in understanding and evaluating the plant ability to mitigate the consequence of multiple SGTR event.

Seul, Kwang Won; Bang, Young Seok; Kim, In Goo [KINS, Taejon (Korea, Republic of); Yonomoto, Taisuke; Anoda, Yoshinari [Japan Atomic Energy Research Institute, Ibaraki (Japan)

2003-06-01

294

Process Monitoring For Safeguards Via Event Generation, Integration, And Interpretation  

International Nuclear Information System (INIS)

There is a recognized safeguards benefit from using process monitoring (PM) on nuclear facilities to complement nuclear materials accountancy. We introduce a model-based approach for PM in which the assessment regarding the state of the monitored system is conducted at a system-centric level. The proposed architecture integrates both time-driven and event-driven data integration and analysis for decision-making. While the time-driven layers of the proposed architecture encompass more traditional PM methods based on time series data and analysis, the event-driven layers encompass operation monitoring methods based on discrete event data integration and analysis. By integrating process- and operation-related information and methodologies within an unified modeling and monitoring framework that includes not only current but also past plant behaviors, the task of anomaly detection is greatly improved because this decision-making approach can benefit from not only known time-series relationships among measured signals but also from known event sequence relationships among generated events. Building from the proposed system-centric PM architecture, we briefly introduce methods that can be used to implement its different components. The application of the proposed approach is then demonstrated via simulation experiments.

295

PROCESS MONITORING FOR SAFEGUARDS VIA EVENT GENERATION, INTEGRATION, AND INTERPRETATION  

Energy Technology Data Exchange (ETDEWEB)

There is a recognized safeguards benefit from using process monitoring (PM) on nuclear facilities to complement nuclear materials accountancy. We introduce a model-based approach for PM in which the assessment regarding the state of the monitored system is conducted at a system-centric level. The proposed architecture integrates both time-driven and event-driven data integration and analysis for decision-making. While the time-driven layers of the proposed architecture encompass more traditional PM methods based on time series data and analysis, the event-driven layers encompass operation monitoring methods based on discrete event data integration and analysis. By integrating process- and operation-related information and methodologies within an unified modeling and monitoring framework that includes not only current but also past plant behaviors, the task of anomaly detection is greatly improved because this decision-making approach can benefit from not only known time-series relationships among measured signals but also from known event sequence relationships among generated events. Building from the proposed system-centric PM architecture, we briefly introduce methods that can be used to implement its different components. The application of the proposed approach is then demonstrated via simulation experiments.

Humberto E. Garcia; Wen-Chiao Lin; Tae-Sic Yoo

2010-07-01

296

Tsunami Hazard Evaluation for the East Coast of Korea by using Empirical Data  

International Nuclear Information System (INIS)

In this study, a tsunami hazard curve was determined for a probabilistic safety assessment (PSA) induced tsunami event in Nuclear Power Plant site. A Tsunami catalogue was developed by using historical tsunami record which happen before 1900 and instrumental tsunami record after 1900. For the evaluation of return period of tsunami run-up height, power-law, uppertruncated power law and exponential function were considered for the assessment of regression curves and compared with each result. Although the total tsunami records were only 9 times at the east coast of Korea during tsunami catalogue, there was no such research like this about tsunami hazard curve evaluation and this research lay a cornerstone for probabilistic tsunami hazard assessment (PTHA) in Korea

297

Tsunami Hazard Evaluation for the East Coast of Korea by using Empirical Data  

Energy Technology Data Exchange (ETDEWEB)

In this study, a tsunami hazard curve was determined for a probabilistic safety assessment (PSA) induced tsunami event in Nuclear Power Plant site. A Tsunami catalogue was developed by using historical tsunami record which happen before 1900 and instrumental tsunami record after 1900. For the evaluation of return period of tsunami run-up height, power-law, uppertruncated power law and exponential function were considered for the assessment of regression curves and compared with each result. Although the total tsunami records were only 9 times at the east coast of Korea during tsunami catalogue, there was no such research like this about tsunami hazard curve evaluation and this research lay a cornerstone for probabilistic tsunami hazard assessment (PTHA) in Korea

Kim, Min Kyu; Choi, In Kil [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

2010-05-15

298

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

Science.gov (United States)

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.

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

2012-04-01

299

Sedimentation and Erosion from Tsunami: A theoretical perspective  

Science.gov (United States)

In the aftermath of a tsunami event, the damage and consequences for society and the environment can be revealed by field surveys. This has been impressively demonstrated over the last few decades. Together with seismic information, numerical modeling can help to analyze tsunami events further, and assure that lessons are learned. However, for paleotsunamis, tsunami deposits are the only sources of information left behind in coastal areas. Inverting information contained in the deposits appears to be an elegant way to estimate characteristics of the incoming wave. To carry out reliable inversions, detailed knowledge of physical processes taking place as well as their coupling is necessary. This paper aims at understanding the response of the water column carrying sediment to tsunami characteristics. The approach is based upon the Rouse equation, which computes a concentration profile of sediment based on the grain size and magnitude of shear stress in a fully turbulent fluid. In the Rouse equation, the Rouse parameter, the ratio between the settling velocity and turbulent fluctuations, plays in the realization of the concentration profile, and indicates whether grains move as bed load or in suspension. Assuming a fully developed boundary layer in the tsunami's flow, a condition that can be achieved in extreme near-shore and onshore regions, the Rouse equation can be integrated from a reference height above the bed to the water surface to compute the total sediment concentration of a certain grain size with given flow characteristics. Increase or decrease of total sediment concentration with time then can be ascribed to erosion and deposition. As an example, an arbitrary point on a beach is taken with a prescribed development of flow depth. For this point and the given flow characteristics, the Rouse parameter is computed for sand (very fine, fine, medium, coarse, very coarse), along with the temporal changes in the total sediment concentration and the amount of sediment (fraction with the total sum of one) being deposited during the deposition phase of the run down. With this simple approach, general conclusions can be made as to the structure within deposits the development of bed forms, i.e., when bed-form generation is possible and whether they can migrate. Also on a broader scale, questions about tsunami erosion vs tsunami sedimentation can be facilitated in the framework of this approach.

Weiss, R.

2008-12-01

300

Washington Tsunami Hazard Mitigation Program  

Science.gov (United States)

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.

Walsh, T. J.; Schelling, J.

2012-12-01

 
 
 
 
301

The origin of the 1883 Krakatau tsunamis  

Science.gov (United States)

Three hypotheses proposed to explain possible causes of the Aug. 27, 1883 Krakatau tsunamis were analyzed: (1) large-scale collapse of the northern part of Krakatau island (Verbeek, 1884), (2) submarine explosion (Yokoyama, 1981), and (3) emplacement of pyroclastic flows (Latter, 1981). A study of timings of the air and sea waves between Krakatau and Batavia, showing that no precise sea wave travel times can be obtained, and a study of the tide and pressure gage records made on August 27, indicating that the air and sea waves were propagated from the focus of eruption on Krakatau island, suggest that neither hypothesis 2 or 3 are sufficiently substantiated. In addition, the event that caused the major air and sea wave was preceded (by 40 min) by a similar, smaller event which generated the second largest tsunami and an air wave. It is concluded that the most likely mechanism for the eruption is a Mt. St. Helens scenario, close to the hypothesis of Verbeek, in which collapse of part of the original volcanic edifice propagated a major explosion.

Francis, P. W.

1985-01-01

302

Modeling of Tsunami Currents in Harbors  

Science.gov (United States)

Extreme events, such as large wind waves and tsunamis, are well recognized as a damaging hazard to port and harbor facilities. Wind wave events, particularly those with long period spectral components or infragravity wave generation, can excite resonance inside harbors leading to both large vertical motions and strong currents. Tsunamis can cause great damage as well. The geometric amplification of these very long waves can create large vertical motions in the interior of a harbor. Additionally, if the tsunami is composed of a train of long waves, which it often is, resonance can be easily excited. These long wave motions create strong currents near the node locations of resonant motions, and when interacting with harbor structures such as breakwaters, can create intense turbulent rotational structures, typical in the form of large eddies or gyres. These gyres have tremendous transport potential, and have been observed to break mooring lines, and even cause ships to be trapped inside the rotation, moving helplessly with the flow until collision, grounding, or dissipation of the eddy (e.g. Okal et al., 2006). This presentation will introduce the traditional theory used to predict wave impacts on harbors, discussing both how these models are practically useful and in what types of situations require a more accurate tool. State-of-the-art numerical models will be introduced, with a focus on recent developments in Boussinesq-type modeling. The Boussinesq equations model can account the dispersive, turbulent and rotational flow properties frequently observed in nature. Also they have the ability to coupling currents and waves and can predict nonlinear wave propagation over uneven bottom from deep (or intermediate) water area to shallow water area. However, during the derivation of a 2D-horizontal equation set, some 3D flow features, such those driven by as the dispersive stresses and the effects of the unresolved small scale 3D turbulence, are excluded. Consequently, there must be some limitations for predicting the turbulent flow structures, even if they are dominantly 2D-horizontal motions. In this paper, the turbulent motions due to long waves and currents, with a focus on port and harbor effects, is investigated. Recent work studying wind wave evolution inside harbors and tsunami effects inside and near harbors will be presented. Presented case studies will focus on the generation of turbulent eddies by structures such as breakwaters and wharves, and the controlling effects these eddies have on currents. The knowledge that these types of currents might occur in a harbor is very important for planning, and for emergency operations during such an event. Okal, E.A., Fritz, H.M., Synolakis, C.E., Raad, P.E., Al-Shijbi, Y., and Al-Saifi, M., 2006. Field survey of the 2004 Indian Ocean tsunami in Oman, 2004, Great Sumatra Earthquakes and Indian Ocean Tsunamis of December 26, 2004 and March 28, 2005, Earthquake Spectra 22 (S4), June 2006.

Lynett, P. J.

2010-12-01

303

Tool for Generating Realistic Residential Hot Water Event Schedules: Preprint  

Energy Technology Data Exchange (ETDEWEB)

The installed energy savings for advanced residential hot water systems can depend greatly on detailed occupant use patterns. Quantifying these patterns is essential for analyzing measures such as tankless water heaters, solar hot water systems with demand-side heat exchangers, distribution system improvements, and recirculation loops. This paper describes the development of an advanced spreadsheet tool that can generate a series of year-long hot water event schedules consistent with realistic probability distributions of start time, duration and flow rate variability, clustering, fixture assignment, vacation periods, and seasonality. This paper also presents the application of the hot water event schedules in the context of an integral-collector-storage solar water heating system in a moderate climate.

Hendron, B.; Burch, J.; Barker, G.

2010-08-01

304

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

Science.gov (United States)

Correctly characterizing tsunami source generation is the most critical component of modern tsunami forecasting. Although difficult to quantify directly, a tsunami source can be modeled via different methods using a variety of measurements from deep-ocean tsunameters, seismometers, GPS, and other advanced instruments, some of which in or near real time. Here we assess the performance of different source models for the destructive 11 March 2011 Japan tsunami using model–data comparison for the generation, propagation, and inundation in the near field of Japan. This comparative study of tsunami source models addresses the advantages and limitations of different real-time measurements with potential use in early tsunami warning in the near and far field. The study highlights the critical role of deep-ocean tsunami measurements and rapid validation of the approximate tsunami source for high-quality forecasting. We show that these tsunami measurements are compatible with other real-time geodetic data, and may provide more insightful understanding of tsunami generation from earthquakes, as well as from nonseismic processes such as submarine landslide failures.

Yong, Wei; Newman, Andrew V.; Hayes, Gavin P.; Titov, Vasily V.; Tang, Liujuan

2014-01-01

305

Computational particle physics for event generators and data analysis  

International Nuclear Information System (INIS)

High-energy physics data analysis relies heavily on the comparison between experimental and simulated data as stressed lately by the Higgs search at LHC and the recent identification of a Higgs-like new boson. The first link in the full simulation chain is the event generation both for background and for expected signals. Nowadays event generators are based on the automatic computation of matrix element or amplitude for each process of interest. Moreover, recent analysis techniques based on the matrix element likelihood method assign probabilities for every event to belong to any of a given set of possible processes. This method originally used for the top mass measurement, although computing intensive, has shown its efficiency at LHC to extract the new boson signal from the background. Serving both needs, the automatic calculation of matrix element is therefore more than ever of prime importance for particle physics. Initiated in the 80's, the techniques have matured for the lowest order calculations (tree-level), but become complex and CPU time consuming when higher order calculations involving loop diagrams are necessary like for QCD processes at LHC. New calculation techniques for next-to-leading order (NLO) have surfaced making possible the generation of processes with many final state particles (up to 6). If NLO calculations are in many cases under control, although not yet fully automatic, even higher precision calculations involving processes at 2-loops or more remain a big challenge. After a short introduction to particle physics and to the related theoretical framework, we will review some of the computing techniques that have been developed to make these calculations automatic. The main available packages and some of the most important applications for simulation and data analysis, in particular at LHC will also be summarized (see CCP2012 slides [1])

306

Electric generating capacity risk assessment using discrete event simulation  

Energy Technology Data Exchange (ETDEWEB)

Risks are expected to occur in power systems as a result of changing load demands. These risks need to be assessed and quantified so that information about the system's status is easy to comprehend and interpret by decision makers. Risk assessment and evaluation provide probabilistic measures of the system's performance which help in assessing past performance and predicting future performance. This paper presented a risk assessment framework for evaluating the electric power supply's sustainability and reliability using a discrete event simulation technique. The generating capacity system welfare status was observed via the resulting difference between the generated power and load demand (also known as power reserve). The evaluation consisted of three risk indices which were used to evaluate the past performance of the generation system and suggest possible future behaviour. These indices included the probability of loss of reserve power, the expected power reserve, and the expected restoration time. The paper presented an overview of the proposed simulation model and discussed each of the simulation model modules. These included generation capacity, load demand and restoration time. The paper also discussed application of the proposed model using the Kuwait generation capacity system as a case study. 14 refs., 1 tab., 3 figs.

Alsayegh, O. [Kuwait Inst. for Scientific Research, Safat (Kuwait)

2006-07-01

307

Cosmic ray interaction event generator SIBYLL 2.1  

International Nuclear Information System (INIS)

The cosmic ray interaction event generator Sibyll is widely used in extensive air shower simulations. We describe in detail the properties of Sibyll 2.1 and the differences with the original version 1.7. The major structural improvements are the possibility to have multiple soft interactions, introduction of new parton density functions, and an improved treatment of diffraction. Sibyll 2.1 gives better agreement with fixed target and collider data, especially for the inelastic cross sections and multiplicities of secondary particles. Shortcomings and suggestions for future improvements are also discussed.

308

Foam: A General-Purpose Cellular Monte Carlo Event Generator  

Digital Repository Infrastructure Vision for European Research (DRIVER)

A general purpose, self-adapting, Monte Carlo (MC) event generator (simulator) is described. The high efficiency of the MC, that is small maximum weight or variance of the MC weight is achieved by means of dividing the integration domain into small cells. The cells can be $n$-dimensional simplices, hyperrectangles or Cartesian product of them. The grid of cells, called ``foam'', is produced in the process of the binary split of the cells. The choice of the next cell to be di...

Jadach, S.

2002-01-01

309

How volcanic eruptions cause tsunamis  

Science.gov (United States)

This study investigates the effect of pyroclastic flows on tsunami generation. The authors analyzed several possible mechanisms that occur when the particle rich flows encounter water and conclude that the volume and density of the basal flow has a close correlation with the wave's amplitude and wavelength, which can be used to model the water movement in lakes, bays and oceans.

Watts, Phil; Waythomas, C. F.; Agu

310

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

Science.gov (United States)

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.

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

2011-12-01

311

Economic impacts of the SAFRR tsunami scenario in California: Chapter H in The SAFRR (Science Application for Risk Reduction) Tsunami Scenario  

Science.gov (United States)

This study evaluates the hypothetical economic impacts of the SAFRR (Science Application for Risk Reduction) tsunami scenario to the California economy. The SAFRR scenario simulates a tsunami generated by a hypothetical magnitude 9.1 earthquake that occurs offshore of the Alaska Peninsula (Kirby and others, 2013). Economic impacts are measured by the estimated reduction in California’s gross domestic product (GDP), the standard economic measure of the total value of goods and services produced. Economic impacts are derived from the physical damages from the tsunami as described by Porter and others (2013). The principal physical damages that result in disruption of the California economy are (1) about $100 million in damages to the twin Ports of Los Angeles (POLA) and Long Beach (POLB), (2) about $700 million in damages to marinas, and (3) about $2.5 billion in damages to buildings and contents (properties) in the tsunami inundation zone on the California coast. The study of economic impacts does not include the impacts from damages to roads, bridges, railroads, and agricultural production or fires in fuel storage facilities because these damages will be minimal with respect to the California economy. The economic impacts of damage to other California ports are not included in this study because detailed evaluation of the physical damage to these ports was not available in time for this report. The analysis of economic impacts is accomplished in several steps. First, estimates are made for the direct economic impacts that result in immediate business interruption losses in individual sectors of the economy due to physical damage to facilities or to disruption of the flow of production units (commodities necessary for production). Second, the total economic impacts (consisting of both direct and indirect effects) are measured by including the general equilibrium (essentially quantity and price multiplier effects) of lost production in other sectors by ripple effects upstream and downstream along the supply chain. An appropriate measure of the economic impacts on the California economy for the SAFRR tsunami scenario is the reduction in GDP. The economic impacts are first calculated without resilience, the ability of the economy to adjust to disruptions in ways that mute potential negative impacts. There are many types of resilience, including using existing inventories of materials, using unused capacity, conserving inputs, substituting for disrupted supplies, recapturing production after the disruption is restored, and many others. A method for estimating resilience, identified in the port system and sectors affected by property damages, is applied to indicate potential reductions of direct and total economic impacts. In this SAFRR tsunami scenario analysis of economic impacts to California, we implement established techniques used to model the economic impacts for two previous U.S. Geological Survey (USGS) scenarios: the southern California Shakeout earthquake (Rose and others, 2011) and the California ARkStorm severe winter storm (Sue Wing and others, written commun., 2013). For the SAFRR tsunami scenario, we reviewed the relevant studies that assess economic impacts from previous tsunami events affecting California and elsewhere and estimate the economic impacts of potential tsunami and other threats to POLA and POLB. To our knowledge, assessment of impacts to the California economy from distant source tsunamis does not exist. Previous tsunamis, including those from the 1960 Chile earthquake, the 1964 Alaska earthquake, the 2008 Chile earthquake and the 2011 Japan earthquake, had only relatively minor or very localized severe damage (such as that in Crescent City in 1964), and no studies of the economic impacts were completed. A rare study of the economic impacts of a tsunami event has recently been produced for the Tohoku earthquake and tsunami (Kajitani and others, 2013). Quarterly declines in Japan’s GDP are observed to peak at ?1.63 percent in the second quarter after the event and stagnate for the rest of th

Wein, Anne; Rose, Adam; Sue Wing, Ian; Wei, Dan

2013-01-01

312

Tsunami diaries  

Directory of Open Access Journals (Sweden)

Full Text Available Inspired by recent discussion on how Serbian media influenced allegedly indifferent reaction of the public to the aftermath of tsunami, this paper examines the role of electronic media in Serbia, television in particular, in regard to their function as a central communication channel for acquiring knowledge about world surroundings. With a premise of having cultural and discursive power, Dnevnik, the central news program of the Serbian public broadcaster, is taken as a paradigmatic media text for analysis in order to examine ways in which global affairs and phenomena are portrayed and structured in television representation of reality. It is suggested that it is fair to conclude that world affairs are marginalized within the representational frame of news broadcasts, and that the media discourse could be depicted as dominantly introverted when it comes to global flow of information and cultural meanings, which is significant regarding cultural perception of world realities among Serbian audiences.

Radovi? Sr?an