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The tsunami-height reduction using a very large floating structure, i.e., VLFS, is discussed, with the water waves, interacting with a floating thin-plate, simulated numerically. The final tsunami-height reduction rate increases, as VLFS length, VLFS flexural rigidity, or the wave height of an incident tsunami, is increased. If two VLFSs are utilized, the final tsunami-height reduction rate, also depends on the distance between the VLFSs. In two-dimensional tsunami propagation, another wave propagates to the outside, along the crest line of the main wave, leading to an additional tsunami-height reduction.

Validation of Potential Tsunami Based on Rupture Duration Estimation and Tsunami Modeling in the West Sumatran Region (Case Study: Nias 2005 and Mentawai 2010 Earthquakes). This research was conducted in the earthquake areas in the West Sumatra to determine the characteristics of tsunami generation through estimation of rupture duration and modeling of tsunamis. The case studies were carried out at two incidents: earthquake in Nias on March 28, 2005 and in Mentawai on October 25, 2010. The purpose of this study was to estimate the characteristics of potential earthquaketriggering tsunamis in the western region of Sumatra based on the duration of rupture, which was then validated by a tsunami modeling. A method for validation was carried out by analyzing a potency of a tsunami based on the earthquake source (source modeling), the propagation of the tsunami wave (ocean modeling), and the height of the tsunami (run-up tsunami). The results showed the duration of the earthquakes in Nias rupture (2005) and Mentawai rupture (2010) were more than 50 seconds, thus, both earthquakes promoted tsunami. The results of tsunami propagation revealed that the tsunami had spread to some areas near the source of the Nias earthquake after 58 minutes and 20 seconds. The area affected by the Nias tsunami included the Salaut island, a section at northwestern Simeulue, a section at southwestern Simeulue, Babi island, Bangkuru island, Tuangku island, Singkil, Sarangbaung, Asu island, southwestern Lagundri Nias, and Northwestern Batu island. The highest tsunami hit Babi island with the magnitude of 13.80 m. Moreover, the tsunami affected the wider areas in Mentawai including the beaches of Batimonga, Ghobi, Tumale, Pasangan, Sabeugunggung, Malacopa, and Asahan with the highest value of run-up on Malacopa beach was 8.17 m.

This paper reports the effects of 2004 Indian Ocean tsunami onto the Ulee Lheue harbour facility, Banda Aceh – Indonesia. The breakwater that had damaged after tsunami were rebuilt into its original design once more due to UNDP funding source. As the existing construction knowing how much the chance it stands againts the tsunami in various terms would be decent for further improvement. This research aim is to measure the capabilities of the breakwater againts the various tsunami scenario. performing the numerical simulation to analyze the hydrodynamics we used both COMCOT and Delft3D-flow for tsunami propagation in line with the hydrodynamics. Several observation points were deployed representing each part of the breakwater. The process revealed that the breakwater only able to hold 8.0 Mw induced wave from overtopping. uniquely when 8.2 Mw tsunami wave strikes the breakwater till overtopped but not giving enough energy to move the boulder aside. Potential movement of the boulder occurred when the 8.4 Mw tsunami wave come through the breakwater produced 77.12 m (5.88 %) damaged structure. The 8.6 Mw single fault highest magnitude gave 209.32 m long (15.97%) destruction upon this Ulee Lheue Harbour breakwater.

The Great East Japan Earthquake occurred on March 11, 2011, in the coastal sea area of northeastern Japan. The epicenter was located close to the seashore. The big tsunami that was generated caused extensive damage. Over the entire Pacific coastal region, tsunami warnings and tsunami advisories were issued continuously. The short arrival time of the tsunami and late evacuation are thought to explain the extensive damage suffered. If early forecasting of tsunami propagation becomes possible, it is believed that tsunami damage will be reduced and safety from tsunamis can be ensured. This paper deals with a method of early forecasting of tsunami propagation. The AIS data obtained from many sailing ships were used and analyzed for estimating tsunami propagation. It was confirmed that this method was very original and effective.

The islands in the Marquesas archipelago are most exposed to far-field tsunamis in French Polynesia. Four recent earthquakes located at the Pacific rim (Kurile 1994, Chile 1995, Mexico 1995 and Peru 1996 earthquakes) generated trans-Pacific tsunamis and caused contrasting inundations in several inhabited Marquesian bays. The aim of this study is to better understand the amplification phenomena observed in the Marquesas Islands and to improve the risk assessment. We present here numerical simulations of these four tsunamis by means of a finite difference model solving the equations of tsunami propagation at different scales. The water heights computed in the bays are in excellent agreement with the available observations and thus validate our numerical method. These numerical results allow us to determine (1) which propagation azimuths are dangerous for the whole Marquesas archipelago and (2) the behavior of each studied bay (amplitude, frequency) in response to tsunami waves. We observe that the seismogenic subduction zone along South America is likely to define one of the most dangerous tsunami generation areas for the Marquesas archipelago, owing to the source geometries and to the trapping of the tsunami energy by bathymetric features in the southern Pacific Ocean (fracture zones, seamount chains).

Prognostic characteristics of potential tsunamis in the East (Japan) Sea are discussed. Zones of tsunami sources for potential danger are selected using the seismic gap theory. Numerical model based on linear long wave theory is used to simulate the tsunami propagation from 28 potential tsunamigenic earthquakes. As a result, the synthetic tsunami catalogue is obtained for each coastal point along the east Korean coast. Statistical analysis of data for tsunami wave height distribution can be described by the log-normal curve. On the average, maximal value of tsunami wave height in each point does not exceed the mean value of computed wave heights by more than six times.

Tsunami propagation is analyzed for the Ligurian Sea with particular attention on the French coasts of the Mediterranean. Historical data of tsunami manifestation on the French coast are analyzed for the period 2000 B.C.–1991 A.D. Numerical simulations of potential and historical tsunamis in the Ligurian Sea are done in the context of the nonlinear shallow water theory. Tsunami wave heights as well as their distribution function is calculated for historical tsunamis and it is shown that the log-normal distribution describes reasonably the simulated data. This demonstrates the particular role of bottom irregularities for the wave height distribution function near the coastlines. Also, spectral analysis of numerical tide-gauge records is done for potential tsunamis, revealing the complex resonant interactions between the tsunami waves and the bottom oscillations. It is shown that for an earthquake magnitude of 6.8 (averaged value for the Mediterranean Sea) the tsunami phenomenon has a very local character but with long duration. For sources located near the steep continental slope in the vicinity of the French-Italian Rivera, the tsunami tide-gauge records in the vicinity of Cannes – Imperia present irregular oscillations with a characteristic period of 20–30 min and a total duration of 10–20 h. For the western French coasts the amplitudes are significantly less with characteristic low-frequency oscillations (period of 40 min–1 h).

Basic tsunami physics of propagation and run-up is discussed for the simple geometry of a channel. We will try to understand how linear and nonlinear processes occurring in a tsunami should influence approach taken to numerical computations.

Most of the tsunami modelling studies have been carried out within the framework of incompressible fluid theory. Estimations we made show that this approach quite appropriately describes the stages of tsunami propagation and run-up, whereas incompressible fluid theory fails to describe the process of tsunami generation properly. Comparative studies of wave generation by piston bottom displacements in compressible and incompressible fluids have been carried out within the framework of linear potential theory. The analysis of exact analytical solutions to the problem has shown that a substantial difference exists between the behaviour of compressible and incompressible fluids under typical tsunami source conditions. It was also shown that bottom displacements of seismic origin must give rise to standing acoustic waves in the source region. As a result each tsunami should have its own “voice”, the characteristics of which depend on bottom topography, sediment features and on the time history and spatial structure of the bottom displacement. This “voice” may serve as an additional important tool for tsunami forecasting.

The evolution of the volcano activity in Montserrat could lead to the collapse of a portion of the lava dome in the Tar River Valley and to a sudden entry of debris avalanche into the Caribbean Sea. The impact of a debris avalanche with a volume of 40× 10 6 m 3 into the sea and the generated tsunami have been simulated numerically by a mixture model solving the 3D Euler's equations. The mixture is composed of sediments considered as an homogeneous fluid of density 2 and of water. Numerical tests show that the generated waves are sensitive to both initial impact velocities and avalanche fronts of the landslide. The water surface and velocities calculated by the 3D mixture model are used as input data in a non-linear shallow water model, to calculate tsunami propagation along the coasts of Montserrat. The hydraulic risks in Montserrat are roughly assessed for a tsunami generated by a mass of 40×10 6 m 3 entering the sea.

The February 1996 Peruvian earthquake generated a larger tsunami than expected from its surface magnitude. This discrepancy as well as the long rupture duration indicate that this event is a ‘tsunami earthquake’. The associated tsunami was strong locally with runup heights of 1 to 5 meters along a coastline of 400 km. It is shown that this tsunami can be modeled for a seismic moment of 2.1020 Nm, using a rigidity of 2.1010 N/m². The tsunami propagation is modeled solving long wave equations by a finite difference method. The maximum run-up heights in the region of Chimbote can be simulated using a grid increment of 10 meters. The propagation of this small tsunami across the Pacific Ocean is modeled taking into account frequency dispersion. The only notable amplification occurred in the Marquesas Islands where wave heights of 2 meters were observed and are simulated.

The tsunami generated by the 1755.01.11 earthquake affected mainly the coasts of the Iberian Peninsula and Northwest Morocco and was observed all over the North Atlantic coasts. The catastrophic dimensions of that phenomenon had a tremendous impact on the city of Lisbon and on several villages along the south coast of Portugal. The earthquake was felt all over Europe and the seismic intensity was estimated as X–XI (Mercalli Intensity Scale) at Lisbon and Southwest Portugal (Cape S. Vicente). The most destructive waves were observed along the coast of Portugal, specially in Lisbon, in the area of the S. Vicente Cape, along the Gulf of Cadiz and Northwest Morocco. Throughout historic times, earthquakes have periodically affected the city of Lisbon causing severe damage and casualties. In spite of that, the city kept growing, so the extension of damage and the loss of human lives in 1755, was quite impressive. The down town of Lisbon was flooded by the rising of the waters of the river Tagus and most historical documents reported waves of 6 m height. At Cape S. Vicente (Southwest Portugal) the run-up height, evaluated from historical data, is greater than 15 m. The eye witness accounts from Spain and Morocco reported wave heights greater than 10 m and large flooded areas along the Gulf of Cadiz and in several harbours in Morocco, e.g. Safi and Agadir. In the city of Lisbon, the number of casualties due exclusively to the tsunami, is estimate around 900, and the penetration of the waters is evaluated to be 250 m. Most of the available literature concerning the 1755 earthquake is based on the compilation of Pereira de Sousa (1919) and, sometimes, incorporates both well established historical records and non reliable information. As the 1755 event evaluation is crucial to a quantitative approach of the tsunami hazard and risk assessment in Portugal, a new examination of the historical records was needed before the establishment of reliable tsunami parameters that can be used both in numerical models of tsunami propagation and in geodynamic studies. In this paper, we present a new compilation of almost all the available historical data from the countries affected by the tsunami. In the analysis of these records, the following tsunami parameters are inferred: travel time, polarity of the first movement, maximum run-up height, period, number of waves, duration of the sea disturbance and extent of flooding.

The island of Rhodes (Aegean Sea, Greece) has been repeatedly hit by tsunamis in the past due to the numerous tsunamigenic sources present in the area, most of which are seismic. Here an investigation is made on the most recent event that occurred on March 24, 2002 in the northeast of the island: unexpected waves affected a 2 km long coastal segment, overtopping part of the sea-wall (3-4 m high) that runs along the littoral road a few km away from the city of Rhodes. Data on the tsunami are poor. Due to the lack of evidence of seismological or meteorological causes, the hypothesis of a landslide source for the tsunami is here explored by means of numerical codes implementing models both for the landslide dynamics and the tsunami propagation. The reconstructed failing mass is located at about 100 m sea depth with a volume of 30 million m3. A sensitivity analysis is further run by varying the source volume, to evaluate the effects on the tsunami impact.

The Vietnamese coast faces the East Sea, which has been recognized as having the potential to generate devastating tsunamis, thus requiring a careful consideration of tsunami risk. In this chapter, tsunami risk and vulnerability are analyzed based on the numerical simulation of tsunami propagation and the social and geographical background of Vietnam. The numerical simulation of a potentially hazardous earthquake scenario in the Manila Trench shows the distributions of the maximum tsunami amplitude and arrival time along the Vietnamese coast. When discussing the vulnerability of the coastline, particular attention is given to three main elements affecting this type of potential disaster in Vietnam: the extensive area of low-lying ground, namely large deltas; a lack of past experience regarding tsunami events; and underdeveloped tsunami mitigation measures. Tsunami mitigation measures implemented recently in coastal communities in Vietnam, such as tsunami warning stations and tsunami drills, are also mentioned.

On the 30th July 1995, an earthquake with magnitude of 8.1 occurred off the coast of Chile. The associated tsunami propagated across the Pacific ocean and reached French Polynesia 10 hours after the seismic event with maximum run-up heights of about 2.5 meters. The most affected islands in French Polynesia were the Marquesas Islands that present few outer reefs, more gradual bottom slopes and large bays. The tsunami propagation has been modeled from Chile to Polynesian Islands, solving the shallow water equations. The water surface initialisation has been computed from Okada's formulas, using seismic parameters of Ruegg (1996). The tsunami propagation is simulated by a finite-difference numerical model using a system of multiple grids with different grid sizes. The computed waves are in fair agreement with the recorded waves along the Chilean coasts, in Tahiti and in Nuku Hiva. The numerical results obtained in the Marquesas Islands confirm the observations of numerous eyewitnesses.

This paper seeks to investigate the effectiveness of sea-defense structures in preventing/reducing the tsunami overtopping as well as evaluating the resulting tsunami impact at El Jadida, Morocco. Different tsunami wave conditions are generated by considering various earthquake scenarios of magnitudes ranging from Mw = 8.0 to Mw = 8.6. These scenarios represent the main active earthquake faults in the SW Iberia margin and are consistent with two past events that generated tsunamis along the Atlantic coast of Morocco. The behaviour of incident tsunami waves when interacting with coastal infrastructures is analysed on the basis of numerical simulations of near-shore tsunami waves' propagation. Tsunami impact at the affected site is assessed through computing inundation and current velocity using a high-resolution digital terrain model that incorporates bathymetric, topographic and coastal structures data. Results, in terms of near-shore tsunami propagation snapshots, waves' interaction with coastal barriers, and spatial distributions of flow depths and speeds, are presented and discussed in light of what was observed during the 2011 Tohoku-oki tsunami. Predicted results show different levels of impact that different tsunami wave conditions could generate in the region. Existing coastal barriers around the El Jadida harbour succeeded in reflecting relatively small waves generated by some scenarios, but failed in preventing the overtopping caused by waves from others. Considering the scenario highly impacting the El Jadida coast, significant inundations are computed at the sandy beach and unprotected areas. The modelled dramatic tsunami impact in the region shows the need for additional tsunami standards not only for sea-defense structures but also for the coastal dwellings and houses to provide potential in-place evacuation.

Catastrophic wave erosion on the southeastern coast of Australia has been attributed to a Hawaiian tsunami generated by the Alika 2 debris avalanche approximately 105 000 years ago. We examine the likelihood of a Hawaiian underwater mega‐landslide as the tsunami's source through numerical tsunami propagation modelling, performed using the SWAN code which solves the non‐linear long‐wave equations. The tsunami generation and propagation was modelled using twenty minute ETOPO5 topography for the Pacific Basin. Results for a hypothetical avalanche in the Hawaiian Islands ten times the volume of the Alika 2 debris avalanche show that Hawaii cannot be the source for a 15 m wave on the Australian coast. An asteroid impact in the central Pacific is examined as an alternative source for the erosional wave. Modelling results indicate that the impact of a 6 km asteroid could generate significant wave run‐up along the southeastern coast of Australia.

On the 22th May 1960, an earthquake with magnitude of 8.5 occurred off the coast of Chile. The associated tsunami propagated across the Pacific ocean and reached French Polynesia 10 hours after the seism with maximum run-up heights of 10 metres. The most affected islands in French Polynesia were the Marquesas that present few outer reefs, more gradual bottom slopes and large bays. The different phases of tsunami life (generation, propagation and impact on the coast) have been modelled from Chile to Polynesian islands, solving the shallow water equations. The water surface initialisation has been computed from Okada's formulas, using seismic parameters of Cifuentes. The tsunami propagation is simulated by a finite-difference numerical model using a system of multiple grids with different grid sizes. The computed waves are in fair agreement with the recorded waves along the Chilean coasts and in Tahiti. The numerical results obtained in the Marquesas islands confirm the observations of 1960.

This paper focuses on the numerical modelling of tsunami propagation in the open Black Sea. Two types of numerical models are discussed: a model for the radial propagation of long waves and an evolutionary finite-difference prognostic model. Experimentally derived numerical data on the model source of tsunamis are reported.

The 2010 Chile tsunami had different effects along the Chilean coast. Seawater surged hundred meters into many rivers, though field surveys showed that the 2 km wide Biobio River did not experience any flooding. In a similar manner, the coastal zones sout

Nowadays numerical models are a powerful tool in tsunami research since they can be used (i) to reconstruct modern and historical events, (ii) to cast new light on tsunami sources by inverting tsunami data and observations, (iii) to build scenarios in the frame of tsunami mitigation plans, and (iv) to produce forecasts of tsunami impact and inundation in systems of early warning. In parallel with the general recognition of the importance of numerical tsunami simulations, the demand has grown for reliable tsunami codes, validated through tests agreed upon by the tsunami community. This paper presents the tsunami code UBO-TSUFD that has been developed at the University of Bologna, Italy, and that solves the non-linear shallow water (NSW) equations in a Cartesian frame, with inclusion of bottom friction and exclusion of the Coriolis force, by means of a leapfrog (LF) finite-difference scheme on a staggered grid and that accounts for moving boundaries to compute sea inundation and withdrawal at the coast. Results of UBO-TSUFD applied to four classical benchmark problems are shown: two benchmarks are based on analytical solutions, one on a plane wave propagating on a flat channel with a constant slope beach; and one on a laboratory experiment. The code is proven to perform very satisfactorily since it reproduces quite well the benchmark theoretical and experimental data. Further, the code is applied to a realistic tsunami case: a scenario of a tsunami threatening the coasts of eastern Sicily, Italy, is defined and discussed based on the historical tsunami of 11 January 1693, i.e. one of the most severe events in the Italian history.

After the last Holocene sea level rise (about 6900 BP), the Gulf of Tartessos extended over the south western area of the nowadays Guadalquivir Valley (Spain). With the development of some deposi tional littoral landforms and the progressive infill, the system evolved towards an inland lagoon. The first political system in the area emerged and collapsed from the fourth to the second millennium BC. Around the first millennium BC the culture of Tartessos flourished in this area under the Phoenician influence, but it vanished by the sixth century BC. The quest of its lost capital, the city of Tartessos, has been one of the most exciting archaeological enterprises in the past century. The former coastline and the ba thymetry of the gulf can be reasonably reconstructed from geo-archaeological studies, and it can be used for the numerical modeling of tide and tsunami propagation in this water body. Models, with a spatial resolution of 30 s of arc, are based on the 2D non-linear hydrodynamic equations and have been pre viously validated under nowadays conditions. Computed tidal elevations and currents can provide some insight on the ancient trades for ship traffic and fisheries. The simulation of tsunami propagation, like the catastrophic one of 1755, allows estimating their potential hazardous effects on ancient coastal cities

After the  Great Sumatra-Andaman Tsunami that devastated vast areas bordering the Indian Ocean and claimed over , lives many research activities began to improve tsunami early warning capacities. Among these efforts was a large scientific and development project, the German-Indonesian Tsunami Early Warning System (GITEWS) endeavor. Advanced numerical methods for simulating the tsunami propagation and inundation, as well as for evaluating the measurement data and providing a forecast for precise warning bulletins have been developed in that context. We will take the developments of the GITEWS tsunami modeling as a guideline for introducing concepts and existing approaches in tsunamimodeling and early warning. For tsunami propagation and inundation modeling, numerical methods for solving hyperbolic or parabolic partial differential equations play the predominant role. The behavior of tsunami waves is usually modeled by simplifications of the Navier–Stokes equations. In tsunami early warning approaches, an inverse problem needs to be solved, which can be formulated as follows: given a number ofmeasurements of the tsunami event, what was the source; and when knowing the source, how do future states look like?This problemhas to be solved within a fewminutes in order to be of any use, and the number of available measurements is very small within the first few minutes after the rupture causing a tsunami.

This is a report of the field survey of the November 15, 1994 Mindoro Island, Philippines, tsunami generated by an earthquake (M = 7.0) with a strike-slip motion. We will report runup heights from 54 locations on Luzon, Mindoro and other smaller islands in the Cape Verde passage between Mindoro and Luzon. Most of the damage was concentrated along the northern coast of Mindoro. Runup height distribution ranged 3–4 m at the most severely damaged areas and 2–4 in neighboring areas. The tsunami-affected area was limited to within 10 km of the epicenter. The largest recorded runup value of 7.3 m was measured on the southwestern coast of Baco Island while a runup of 6.1 m was detected on its northern coastline. The earthquake and tsunami killed 62 people, injured 248 and destroyed 800 houses. As observed in other recent tsunami disasters, most of the casualties were children. Nearly all eyewitnesses interviewed described the first wave as a leading-depression wave. Eyewitnesses reported that the main direction of tsunami propagation was SW in Subaang Bay, SE in Wawa and Calapan, NE on Baco Island and N on Verde Island, suggesting that the tsunami source area was in the southern Pass of Verde Island and that the wave propagated rapidly in all directions. The fault plane extended offshore to the N of Mindoro Island, with its rupture originating S of Verde Island and propagating almost directly south to the inland of Mindoro, thereby accounting for the relatively limited damage area observed on the N of Mindoro.

[1] In this study, we investigate the dispersive effects in the 2009 Samoa tsunami through numerical simulations. The wave propagation is first simulated with a weakly nonlinear and dispersive Boussinesq model and a non-dispersive shallow-water-equations model. Comparison of the numerical results between these models indicates that tsunami propagation is significantly affected by the frequency dispersion east of Tonga Trench. Neglecting dispersive effects results in larger wave heights and speeds. The strong frequency dispersion is primarily attributed to the dramatic variation of water surface elevations generated by the earthquake doublet, and enhanced by the uneven bathymetry in Tonga Trench. Tsunami propagation is also simulated with MOST (“Method of Splitting Tsunamis”), which is based on the shallow water equations but uses numerical dispersion to mimic physical frequency dispersion at operational resolutions. A good agreement is observed between MOST and the Boussinesq model, as well as the field measurements in the leading wave. In the shorter trailing waves, agreement becomes poorer due to the mismatch between numerical and physical dispersions.

In this paper, work was carried out to simulate three-dimensional (3-D) tsunami run-up from high resolution remote sensing satellite data of QuickBird. In doing so, the tsunami wave spectra are extracted from QuickBird data using two dimensional di Fourier transform (2-DFFT). The tsunami propagation equation was then solved based on the standard Galerkin finite element approach to simulate 3-D tsunmai run-up. The results of this study have shown that the integration between different mathematical and numerical models is providing accurate 3-D reconstruction and simulation for tsunami run-up. Key words: QuickBird satellite data, tsunami run-up, 2-DFFT, 3-D reconstruction, finite element method, Galerkin finite element.

We use a backprojection method to determine dominant directions of ocean infragravity waves from 60–200 s period from cross correlations between 5 ocean bottom differential pressure gauges located off the coast of Sumatra. We observe infragravity waves arriving from all directions, but there is a dominant source direction that represents coherent propagation along the coast from the southeast or from the south. This study demonstrates the effectiveness of our projection technique, which may be applied to past and future seismic data to improve models of ocean infragravity wave generation and tsunami propagation.

Tsunamis are a potential threat to submarine installations especially when the pipelines traverse the continental slope and shelf. Tsunami propagation simulation for the 26th December 2004 event was carried out for the southeastern shelf and slope regions of India. The velocities generated along the shelf and slope regions in the vicinity of canyons and the shear stresses derived from these velocities are evaluated. A 3D hydrodynamic model with initial surface elevation obtained from the earthquake details was used to drive the tsunami model. Shear stresses along select transects in the vicinity of submarine canyons are studied.

[1] An idealized mathematical model of tsunami evolution in deep sea and across the continental shelf is proposed. The initial value problem in deep sea is related to the well-known Cauchy- Poisson problem and the tsunami propagation across the continental shelf is derived using the linearized shallow water equations. When analyzing different cases of tsunamis in deep sea, it was found that tsunamis evolve into two basic wave types. One resembles a single wave and the other a wave packet. The analysis of different cases of tsunamis at the shoreline reveals that the continental shelf, due to its geometrical properties, serves as a tsunami amplifier, producing tsunami amplitudes up to 20 times larger than those at the edge of the continental shelf. A comparison with tsunami measurements suggests that the idealized model may be used for a reliable assessment of the principle hydrodynamic properties of the tsunami, such as the tsunami amplitude and its half period.

The East Java Tsunami occurred on 3 June, 1994 remind us the possibility that these catastrophic events affect coastal area suddenly, without forewarning. On that occasion, human victims were concentrated in the Bali Island and in the nearly areas; the economic loss were limited on very poor regions, surely the most dramatic consequence of tsunami impact. This event has attracted the interest of the scientific community, increasing the number of geophysics and geodynamic studies, mainly concerning the generative mechanisms and the tsunami propagation. At the same time, studies aiming a better understanding of the morphological effects of past-tsunami impact have been performed along the coasts all around the world (Kelletat, 2009). Recently, the impact of the Indian Ocean Tsunami (IOT) on December 26, 2004 and its charge of about 230,000 victims in Thailand and in other countries facing the Indian Ocean, indigenous and citizen coming from all around the world, underlined the necessity to manage the human activities in coastal areas and to improve of the knowledge of the possible effects of a tsunami impact on the coast. Large coastal sectors were completely inundated, modified or even destroyed by the impact of the IOT (e.g.: Szczuciski et al., 2005; Kelletat et al., 2006, 2007; Lavigne et al., 2006; Richmond et al., 2006; Umitsu et al., 2007; Paris et al., 2007, 2009; Srinivasalu et al., 2007); post event surveys permitted to recognise morphological effects of its impact and, in the same time, to extend all obtained results on coastal sectors where similar evidences were recognised. Notwithstanding the immense number of data derived by the surveys performed all along the coast hit by the IOT, the debate about the correlation of some landforms/sediments and the extreme event responsible of their genesis/deposit is still open. At present, there are not undisputable signatures of landforms and/or fine sediments that allows discrimination between a past-extreme events sea storm, hurricane or tsunami deposition. This knowledge gap has given rise to a growing number of papers that examining the source and nature of landforms and sediments (e.g. Frohlich et al., 2009; Goto et al., 2007; 2010a; Kelletat, 2008; Kelletat et al., 2006, 2007; Mastronuzzi et al., 2006; Paris et al., 2009; Scheffers, 2006, 2008; Scheffers & Kelletat, 2005 and others). New data will come from the more recent events of September 30, 2009 around Samoa Islands and of February 28, 2010 in Chile; this last occurred exactly 50 years after the tsunami that in 1960 hit the coasts of the countries facing the Pacific Ocean (Fig. 1).

This chapter discusses an important global tsunami model that has been able to provide a global picture of the December 2004 tsunami distribution and capture the “new physics” of tsunami propagation in the world oceans is the one developed by Kowalik and colleagues. Tsunamis are typically computed without the Coriolis force because their periods are much smaller than the inertial period. However, as propagation proceeds over long distances, the compounding effect of the Coriolis force may combine and significantly increase. On this assumption, the Kowalik model takes into account the Coriolis force. Kowalik and colleagues computed the December 2004 global tsunami maximum amplitude distributions, one with and one without the Coriolis force, and the difference between the two (i.e., the residual) increased toward the polar regions, since the Coriolis effect increases poleward from the equator. The observed change was particularly significant along the South Pacific Oceanic Ridge.

An earthquake occurred off the west coast of Nicaragua at 18 h 16 m on September 1, 1992. Despite a relatively modest magnitude (Ms = 7.0 Mw = 7.6), the earthquake generated a significant tsunami, which strongly impacted the coast of Nicaragua and was felt at several remote stations. In an attempt to better understand the tsunami propagation and coastal impact, we conducted a field survey on November 2–7, 1992, i.e., roughly 2 months after the event. We emphasized the observation of run‐up and inundation, but also collected a limited number of sand samples and mud cores. A total of 12 sites were surveyed, with multiple stations per site. This article presents the results of the survey, including a detailed discussion of the observation methods and data processing strategies. Observed run‐ups (relative to MSL) were typically in the 4–7 m range, with a maximum run‐up of 9.1 m at San Martin, an open coast site with a steep beach slope. Inundation extents were relatively modest, typically of the orde...

The present paper reports a preliminary result of searching tsunami-affected area using recent advances of GIS analysis and remote sensing combined with a numerical modeling of tsunami propagation/inundation and world population database. Applying the method of searching tsunami affected area to the 2009 Samoa earthquake tsunami and the 2010 Chilean earthquake tsunami, the potential tsunami affected area have been detected at some coastal cities/communities. The results are utilized to detecting tsunami impacted area for conducting disaster relief activities.

The generation of tsunamis with the help of a simple dislocation model of an earthquake and their propagation in the basin are discussed. In this study, we examined the formation of a tsunami wave from an initial sea surface displacement similar to those obtained from earthquakes that have generated tsunami waves and its propagation through the sea to the shore. Linear shallow water wave equations were employed to explain the propagation of the waves in the open sea while nonlinear wave equations were introduced to explain the behaviour of the wave near the shore. The influence of the Coriolis force on the propagation of tsunami was shown to become very important when the tsunami travel distance is significant in relations to the earth’s complete rotation time. The group velocity of tsunami waves which is the velocity of wave energy propagation and its independence on the wave number was demonstrated

International audience; A numerical simulation of the 26th December, 2004 Indian Ocean tsunami of the Tamil Nadu coastal zone is presented. The simulation approach is based on a fully nonlinear Boussinesq tsunami propagation model and included an accurate computational domain and a robust coseismic source. The simulation is first confronted to available tide gauge and runup observations. The agreement between observations and the predicted wave heights allowed a reasonable validation of the simulation. As a result, a full picture of the tsunami impact is provided over the entire coastal zone Tamil Nadu. The processes responsible for coastal vulnerability are discussed.

Problem of tsunami risks evaluation, assessment and mitigation is here addressed. Modern computational technologies are able to calculate accurately tsunami wave propagation over the deep ocean provided that initial displacement (perturbation of the sea bed at tsunami source) is known. Modern deep ocean tsunameters provide direct measurement of the passing tsunami wave in the real time mode, which help to estimate initial displacement parameters right after the tsunami wave is recorded at one of the deep ocean buoys. Therefore, fast tsunami propagation code that can calculate tsunami evolution from estimated model source becomes critical for timely evacuation decision for many coastal communities in case of a strong tsunami. In this paper we discuss a part of MOST (Method of Splitting Tsunami) software package, which has been accepted by the USA National Ocean and Atmosphere Administration as the basic tool to calculate tsunami wave propagation and to evaluate of inundation parameters. Our main objectives are to speed up the existing sequential program, and to adapt this program for shared memory systems (OpenMP), CELL BE architecture and GPU. For caring out this research we use SMP server and a system build on IBM CELL BE CPU. We also use NVIDIA Tesla C1060 board which acts as co-processor for CPU. Optimization of the existing parallel and sequential code for the task of tsunami wave propagation modeling as well as an adaptation of this code for GPU and CELL BE processor is discussed. The obtained results are up to 170 times performance gain for one time step. These are very promising.

Unusual water-level behavior was observed in the western Mediteranean basin due to the most recent tsunami in this region on 21 May 2003. An analysis of seventeen tide-gauge records of this tsunami showed that the generated variability persisted for more than 1 day in most of the stations consisted of several wave trains. These observations suggest reflections at the boundaries and possibly resonant oscillations in the western Mediterranean basin triggered by the tsunamis. In this study we determine the resonant modes of the western Mediterranean basin on the basis of a numerical model. We then assess whether these modes have contributed to the unusual behavior of the 21 May 2003 tsunami.Copyright © 2010 by ASME

The present paper investigates the propagation of potential tsunamis in the Chesapeake Bay. The Chesapeake Bay, located on the east coast of the U.S., is one of the largest estuaries in the world. The U.S. east coast traditionally is believed to be an area free from tsunami impacts. However, historical data and recent research has indicated that the threats of large tsunamis affecting the area cannot be completely discounted. In this study, a summary of tsunamigenic sources and source mechanisms that may affect the Chesapeake Bay region is presented along with simulations of tsunamis propagating inside the bay. The simulations are performed based on a description of incoming tsunami amplitude at the bay entrance and using two-dimensional depth-averaged numerical models. Two models are developed using the linear shallow water equations with Boussinesq approximation and nonlinear shallow water equations with bottom friction. Model results indicate that incoming tsunami waves would dissipate rapidly as they propagate up the shallow bay. The first tsunami wave would reach the mouth of the Potomac River, nearly at the middle of the bay, about 3 hours after the first tsunami wave enters the bay.

Numerical study of dispersion effect for tsunami propagation for the case of Indian Ocean Tsunami has been carried out using three model equations: Linear shallow water (LSW) equations, Nonlinear shallow water (NLSW) equations, and Weakly-Nonlinear Bossuineq-type (WNB) equations. Model simulation results are compared each other and against observations data. General features of tsunami wave patterns are agree very well using the three models but the WNB model produced development in time of tsunami front face which caused by the dispersion effect. Two dimensional wave pattern and spatial profile of sea surface are discussed to study the dispersion effect.

The tsunami, the representative natural hazard, causes tremendous damage to national economy as well as casualties. For example, the South Asia Tsunami occurred on December 26, 2004 killed approximately 300,000 people and deprived property of 10billion USD. So, it is very important to predict a behavior of a tsunami which depends on a water depth variation and a regional characteristic. The former determines the direction of tsunami propagation and the latter may cause wave reflection and resonance. Therefore, in this study, we investigate an effect of these phenomena. Imwon port located at the eastern coast of the Korean peninsula was damaged relatively strongly by the Central East Sea Tsunami because of a water depth variation which makes the wave concentration on this port. Pohang port is located at a caved point of the eastern coast of the Korean Peninsula, it may have a risk that there are some increases of wave heights by wave reflection and resonance effect. To simulate tsunami propagation, the dispersion-correction scheme which is modified to consider the dispersion effect is used. The modified scheme has an advantage of using constant spatial grid and time step sizes even in real topography. In numerical model, a staggered grid system is used. A total domain of the model is divided several sub-regions and dynamic linking technique is used to connect these.

[1] We analyzed short period seismograms recorded at Stromboli, searching for a possible signature of the tsunami following the two landslides occurred on the island on 30 December 2002. By taking advantage of their close occurrence in space and time, we recognized the seismic mark of clock- and counterclockwise tsunami waves trapped by the island coast. The most energetic direct arrivals, running around the island in the two opposite directions, traveled with an average velocity of about 12 m/s, while the waves that traveled more than once around the island display a slightly higher velocity. These observations represent the first instrumental evidence of trapped waves around pseudo-conical islands and demonstrate the possibility of using coastal seismic stations for monitoring tsunami propagation. Our results provide important constraints for early warning of tsunami generated at Stromboli in the Sciara del Fuoco area, where considerable landslides are known to have occurred in the past.

International audience; A numerical simulation of the 26th December 2004 Indian Ocean tsunami for the Andaman and Nicobar Islands case study is presented. The simulation approach is based on a fully nonlinear Boussinesq tsunami propagation model and included an accurate computational domain and a robust coseismic source. The simulation is first confronted to available tide gauge and run-up observations. The agreement between observations and the predicted wave heights allowed a reasonable validation of the simulation. As a result a full picture of the tsunami impact is provided over the entire coastal zone of Andaman and Nicobar Islands. The processes responsible for coastal vulnerability are discussed.