Tsunami Waves

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Identification of Forerunners and Transmission of Energy to Tsunami Waves Generated by Instanteneous Ground Motion on a Non Uniformly Sloping Beach

Identification of Forerunners and Transmission of Energy to Tsunami Waves Generated by Instanteneous Ground Motion on a Non Uniformly Sloping Beach

The problem of generation and propagation of tsunami waves is mainly focused on plane beach, there are very few analytical works where wave generation is considered on non-uniformly sloping beach and as a result those works might have failed to capture important facts which are influenced by bottom-slope of the beach. Some researchers pro- vided solution to the forced long linear waves but on a beach with uniform slope while the importance of including variable bottom topography is mentioned by few researchers but they also stayed away from considering continuous variability of the ocean bed as they were studying runup problem. This paper analyzes tsunami waves which are gener- ated by instantaneous bottom dislocation on a ocean floor with variable slope of the form r
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Tsunami waves generated by submarine landslides of variable volume: analytical solutions for a basin of variable depth

Tsunami waves generated by submarine landslides of variable volume: analytical solutions for a basin of variable depth

For example, an underwater landslide on 17 July 1998 caused the destructive Papua New Guinea tsunami, when the 15-m wave at the coast devastated three villages and took more than 2200 lives (McSaveney et al., 2000; Synolakis et al., 2002). On 17 August 1999 a shore slump in the Izmit Bay (Turkey) generated a 2.5 m high tsunami (Altinok et al., 2001). The problem of tsunami generation by landslides has also been actively discussed in the Atlantic and Caribbean. In particular, three tsunamis in the Lesser Antilles were generated by avalanche flows from the Montserrat volcano in 1997, 2003 and 2006 (O’Loughlin and Lander, 2003; Pelinovsky et al., 2004; Zahibo, 2006). Deplus et al. (2001) reported large-scale debris avalanche deposits around the Lesser Antilles. Particularly, a large area covered by mega blocks up to 2.8 km long and 260 m high is located off Dominica. Large coastal landslides and associated tsunami hazard in the Caribbean are described in (Teeuw et al., 2009). According to their study possible tsunami waves in the vicinity of Dominica can reach 3–10 m due to probable collapse of coastal blocks. Thus, the problem of tsunami generation by landslides is of current scientific interest.
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Mathematical modeling for tsunami waves using lattice boltzmann method

Mathematical modeling for tsunami waves using lattice boltzmann method

Kowalik, Z., Horrillo, J. J., and Kornkven, E. (2005a). In Yeh, H., Liu, P. L.-F., and Synolakis, C., editors, Advanced Numerical Models For Simulating Tsunami Waves And Runup, Chapter Tsunami Generation And Runup Due To 2D Landslide, pages 269-272.World Scientic Publishing Co., New Jersey.

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Nonlinear deformation and run-up of single tsunami waves of positive polarity: numerical simulations and analytical predictions

Nonlinear deformation and run-up of single tsunami waves of positive polarity: numerical simulations and analytical predictions

The nonlinear shallow-water equations, which are used in this study and commonly utilized for tsunami modelling, are also known to neglect dispersive effects. In this con- text, it is important to mention the recent work of Larsen and Fuhrman (2019). They used Reynolds-averaged Navier– Stokes (RANS) equations and k–ω model for turbulence clo- sure to simulate the propagation and run-up of positive sin- gle waves, including full resolution of dispersive short waves (and their breaking) that can develop near a positive tsunami front. They similarly showed that this effect depends on the propagation distance prior to the slope if a simple toe with a slope type of bathymetry is utilized. This work shows that these short waves have little effect on the overall run-up and hence give additional credence to the use of shallow-water equations. These results largely confirm what was previously hypothesized by Madsen et al. (2008), namely that these short waves would have little effect on the overall run-up and inundation of tsunamis (though they found that they could significantly increase the maximum flow velocities).
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Reply to ‘Using remote sensing to assess the protective role of coastal woody vegetation against tsunami waves’

Reply to ‘Using remote sensing to assess the protective role of coastal woody vegetation against tsunami waves’

tsunami damage relative to woody vegetation and conclude that ‘…mangrove forests and coastal shelterbelts provided protection from the [t]sunami.’ Unfortunately, this claim is based on the assumption of ‘homogeneity’ of other factors well known to affect coastal inundation and that covary with degree of vegetation. We argue below that the assumption of homogeneity view is false; indeed, the authors have misrepresented a number of sources in justifying this assumption, and we further demonstrate how their approach cannot, even in principle, evaluate such a claim. We conclude with a call for analyses that can simultaneously assess the role of the many factors generating the pattern of inundation and damage.
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Numerical Simulation of Tsunami in the Black Sea Caused by the Earthquake on September 12, 1927

Numerical Simulation of Tsunami in the Black Sea Caused by the Earthquake on September 12, 1927

In Fig. 3 (right) the model mareograms are shown for the same items. The time of arrival of waves to the observation point is well observed. It is accompanied by an initial rise of the sea level at all points. It can be seen that the first wave is not always maximum. There is a qualitative similarity of the periods of fluctuations numerically calculated and instrumentally fixed. Their numerically obtained amplitudes at some points exceed those fixed by the mareographs. Discrepancy between the results obtained and the available measurements is due to the inability to simulate this event more accurately due to the small amount of information on the earthquake source parameters and amount and time of underwater shocks. In addition, the characteristics of tsunami waves in the coastal area can also be affected by local factors such as surge or seiche fluctuations.
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Meteotsunamis: atmospherically induced destructive ocean waves in the tsunami frequency band

Meteotsunamis: atmospherically induced destructive ocean waves in the tsunami frequency band

Abstract. In light of the recent enhanced activity in the study of tsunami waves and their source mechanisms, we consider tsunami-like waves that are induced by atmospheric processes rather than by seismic sources. These waves are mainly associated with atmospheric gravity waves, pressure jumps, frontal passages, squalls and other types of atmo- spheric disturbances, which normally generate barotropic ocean waves in the open ocean and amplify them near the coast through specific resonance mechanisms (Proudman, Greenspan, shelf, harbour). The main purpose of the present study is to describe this hazardous phenomenon, to show similarities and differences between seismic and meteorolog- ical tsunamis and to provide an overview of meteorological tsunamis in the World Ocean. It is shown that tsunamis and meteotsunamis have the same periods, same spatial scales, similar physical properties and affect the coast in a com- parably destructive way. Some specific features of meteot- sunamis make them akin to landslide-generated tsunamis. The generation efficiency of both phenomena depend on the Froude number (Fr), with resonance taking place when Fr ∼ 1.0. Meteotsunamis are much less energetic than seis- mic tsunamis and that is why they are always local, while seismic tsunamis can have globally destructive effects. De- structive meteotsunamis are always the result of a combina- tion of several resonant factors; the low probability of such a combination is the main reason why major meteotsunamis are infrequent and observed only at some specific locations in the ocean.
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The Geo-Information System Application for Display of the Tsunami Type Long Wave Propagation Modeling Results in the Black Sea Coastal Area

The Geo-Information System Application for Display of the Tsunami Type Long Wave Propagation Modeling Results in the Black Sea Coastal Area

At the moment, Marine Environmental & Information Technologies Depart- ment of FSBSI Marine Hydrophysical Institute RAS is developing such infor- mation systems [13, 14] applying the Mapserver [15]. To provide users with a spe- cial tool for rapid response, the software modules have been created. They permit to visualize the results of work conducted under the guidance of Sergey Dotsenko (numerical simulation of the propagation of nonlinear long tsunami type waves in the sea coastal zone, in bays and gulfs). These modules allow displaying the evolu- tion of waves as they propagate in shallow water and in the coastal zone, and also to quantify their amplitude features. Thus, it becomes possible for the user to quickly predict possible danger in the area of interest of the Black Sea coast due to the exposure of long tsunami waves.
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Tsunami Hazard in the Arabian Gulf Due to Earthquakes in the Makran Subduction Zone

Tsunami Hazard in the Arabian Gulf Due to Earthquakes in the Makran Subduction Zone

It is important to note at this point that other mechanisms (e.g., submarine volcanos or submarine landslides) can be induced by an earthquake and lead to indirect tsunami generation. These effects are not accounted for in the tsunami model for this analysis. Some literature has suggested that volcanic and/or landslide effects were a significant factor in the 1945 Makran tsunami (e.g., Bilham et al. [2007] and Rajendran et al. [2008]). Particularly, these alternate processes could help explain the time lag between multiple tsunami waves reaching Pasni and/or the reports of larger (e.g., 12 to 15 meter) waves, if the reports are in fact true.
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Propagation of Tsunami-like Surface Long Waves in the Bays of a Variable Depth

Propagation of Tsunami-like Surface Long Waves in the Bays of a Variable Depth

Studying the propagation of tsunami waves in various bathymetry basins, the diversity of shapes of lateral boundaries of the oceans and seas should be taken into account. Considerable wave amplification can occur in bays and gulfs with a specific shape. In this case the nature of wave propagation is difficult to predict. Seiche oscillations [13, 14] and various trapped waves [15] can appear in enclosed and semi-enclosed bodies of water. Gulfs often have a shape close to a semi- circular. In the Black Sea these are particularly the Feodosiya Gulf and Gelendzhik Bay.
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GPS water level measurements for Indonesia’s Tsunami Early Warning System

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

of wind-generated waves vary up to 20 s, while astronomical tidal signals in the open ocean have wave periods from about 12 h and more. Typical periods of tsunami waves range from 10 min to one hour. A Butterworth low-pass filter suppresses the wind waves by removing signals with wave periods of less than two minutes. For de-tiding and estimation of the tsunami arrival time at the location of the buoy, the sea level event detection algorithm (SLE) (Sch¨one et al., 2011; P´erez et al., 2009) is applied. The resulting time series including the estimated onset time of a possible tsunami is transmitted via the tsunami service bus (Fleischer et al., 2010) for further use at the Tsunami Warning Center in Jakarta.
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Tsunami run-up estimation based on a hybrid numerical flume and a parameterization of real topobathymetric profiles

Tsunami run-up estimation based on a hybrid numerical flume and a parameterization of real topobathymetric profiles

Abstract. Tsunami run-up is a key value to determine when calculating and assessing the tsunami hazard in a tsunami- prone area. Run-up can be accurately calculated by means of numerical models, but these models require high-resolution topobathymetric data, which are not always available, and long computational times. These drawbacks restrict the ap- plication of these models to the assessment of small ar- eas. As an alternative method, to address large areas em- pirical formulae are commonly applied to estimate run-up. These formulae are based on numerical or physical experi- ments on idealized geometries. In this paper, a new method- ology is presented to calculate tsunami hazard at large scales. This methodology determines the tsunami flooding by us- ing a coupled model that combines a nonlinear shallow wa- ter model (2D-H) and a volume-of-fluid model (RANS 2D- V) and applies the optimal numerical models in each phase of the tsunami generation–propagation–inundation process. The hybrid model has been widely applied to build a tsunami run-up database (TRD). The aim of this database is to form an interpolation domain with which to estimate the tsunami run-up of new scenarios without running a numerical simula- tion. The TRD was generated by simulating the propagation of parameterized tsunami waves on real non-scaled profiles. A database and hybrid numerical model were validated using real and synthetic scenarios. The new methodology provides feasible estimations of the tsunami run-up; engineers and sci- entists can use this methodology to address tsunami hazard at large scales.
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A Review on: Resilience of Tsunami by Mangrove Belt in Surat City

A Review on: Resilience of Tsunami by Mangrove Belt in Surat City

Tsunami waves do not resemble normal undersea currents or sea waves, because their wavelength is far longer. Rather than appearing as a breaking wave, a tsunami may instead initially resemble a rapidly rising tide, and for this reason they are often referred to as tidal waves, although this usage is not favoured by the scientific community because tsunamis are not tidal in nature.[2] Tsunamis generally consist of a series of waves with periods ranging from minutes to hours, arriving in a so-called "train”. Wave heights of tens of metres can be generated by large events.[3] Although the impact of tsunamis is limited to coastal areas, their destructive power can be enormous and they can affect entire ocean basins; the2004 Indian Ocean tsunami was among the deadliest natural disasters in human history with at least 230,000 people killed or missing in 14 countries bordering the Indian Ocean.
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Performance of coastal sea-defense infrastructure at El Jadida (Morocco) against tsunami threat: lessons learned from the Japanese 11 March 2011 tsunami

Performance of coastal sea-defense infrastructure at El Jadida (Morocco) against tsunami threat: lessons learned from the Japanese 11 March 2011 tsunami

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 in- teracting with coastal infrastructures is analysed on the ba- sis 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 bathy- metric, 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. Exist- ing coastal barriers around the El Jadida harbour succeeded in reflecting relatively small waves generated by some sce- narios, but failed in preventing the overtopping caused by waves from others. Considering the scenario highly impact-
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Tsunami hazard for the city of Catania, eastern Sicily, Italy, assessed by means of Worst-case Credible Tsunami Scenario Analysis (WCTSA)

Tsunami hazard for the city of Catania, eastern Sicily, Italy, assessed by means of Worst-case Credible Tsunami Scenario Analysis (WCTSA)

Abstract. Eastern Sicily is one of the coastal areas most ex- posed to earthquakes and tsunamis in Italy. The city of Cata- nia that developed between the eastern base of Etna volcano and the Ionian Sea is, together with the neighbour coastal belt, under the strong menace of tsunamis. This paper ad- dresses the estimation of the tsunami hazard for the city of Catania by using the technique of the Worst-case Credible Tsunami Scenario Analysis (WCTSA) and is focused on a target area including the Catania harbour and the beach called La Plaia where many human activities develop and many im- portant structures are present. The aim of the work is to pro- vide a detailed tsunami hazard analysis, firstly by building scenarios that are proposed on the basis of tectonic consider- ations and of the largest historical events that hit the city in the past, and then by combining all the information deriving from single scenarios into a unique aggregated scenario that can be viewed as the worst virtual scenario. Scenarios have been calculated by means of numerical simulations on com- putational grids of different resolutions, passing from 3 km on a regional scale to 40 m in the target area. La Plaia beach results to be the area most exposed to tsunami inundation, with inland penetration up to hundreds of meters. The har- bour turns out to be more exposed to tsunami waves with low frequencies: in particular, it is found that the major con- tribution to the hazard in the harbour is due to a tsunami from a remote source, which propagates with much longer periods than tsunamis from local sources. This work has been performed in the framework of the EU-funded project SCHEMA.
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Application of a Сhannel Model for Describing Propagation of Tsunami-Like Single Waves in a Channel with Variable Cross-Section

Application of a Сhannel Model for Describing Propagation of Tsunami-Like Single Waves in a Channel with Variable Cross-Section

Conclusion. The Sea of Marmara and the Black Sea are sea basins, where tsunami waves have been observed and are potentially possible [14, 15]. Although tsunami wave is not so frequent phenomenon in these seas, it is of high interest to evaluate its parameters in the strait during the propagation from the Marmara to the Black Sea and vice versa, as well as to evaluate the initial fluid surface displacement in the central part of the strait. These issues are considered within the framework of channel theory of long surface waves using numerical simulation techniques.
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Krakatau (1)

Krakatau (1)

explosion blew away the northern two-thirds of the island and it was almost instantaneously followed by the collapse of the unsupported volcanic chambers which formed the huge underwater caldera. It was the combined effects of the explosion and collapse of the volcano that generated the catastrophic tsunami waves that caused havoc and destruction in the Sunda Strait.

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Reduction of maximum tsunami run-up due to the interaction with beachfront development – application of single sinusoidal waves

Reduction of maximum tsunami run-up due to the interaction with beachfront development – application of single sinusoidal waves

The problem of long waves which are climbing up a plane, sloping beach after propagating over a horizontal bottom is depicted in Fig. 1. Firstly, before the wave front reaches the shoreline, shoaling and refraction constitutes the main wave modification. At a specific water depth or for specific nonlin- earity wave breaking may occur. Yet, Madsen and Fuhrman (2008) pointed out that wave breaking is mostly dedicated to shorter waves riding on top of lower frequent tsunami waves. Then, during their run-up and subsequent draw-down, the approaching tsunami may interact with beachfront develop- ment represented in this study by MR elements positioned at different distances to each other and in different arrange- ments on the beach above the still water line. In order to re- peat this model situation, it is assumed that the first row of MR elements is always at the same distance to the still water line. One possible element combination as well as a longi- tudinal cross section are sketched schematically in Fig. 1, to demonstrate the model assumptions. Though the waves un- der consideration are indeed longer than the slope applied for the experiments, the setting is illustrated in Fig. 1 with spa- tially shorter waves for the sake of clarity. For details of the applied waves the reader is referred to Table 1.
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Aid, social capital and village public goods: after the tsunami

Aid, social capital and village public goods: after the tsunami

Using survey data on fishermen and fishing villages in Aceh, Indonesia from 2005 and 2007, this paper examines the effect of the December 2004 tsunami and resulting massive aid effort on local public good provision, in particular on public labor inputs, but also public capital choices. Also analyzed are the roles of and changes in local social and political institutions and participation in political and social activities. Such an examination informs not only our understanding of the impacts of aid on villages, but also our understanding of how villages allocate resources to pub- lic goods. For public labor inputs, volunteerism is lower in villages with more aid projects, but that is offset if the dominant donor mitigates agency problems by doing its own implementation. Volunteerism is lower in villages with more ’democratic’ activity such as elections, although that effect is mitigated in villages with higher levels of social capital pre-tsunami. Evidence suggests volunteerism is lower not because of changes in types of leaders with village elections per se, but rather due to heightened internal divisions associated with elections. Correspondingly for public capital, villages with more democratic activity combined with more aid projects tend to emphasize garnering private aid (e.g., houses) at the expense of public aid (e.g., public buildings).
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Three dimensional numerical modeling of tsunami related internal gravity waves in the Hawaiian atmosphere

Three dimensional numerical modeling of tsunami related internal gravity waves in the Hawaiian atmosphere

The tremendous tsunami following the 2011 Tohoku Earthquake produced internal gravity waves (IGWs) in the neutral atmosphere and large disturbances in the overlying ionospheric plasma while propagating through the Pacific ocean. To corroborate the tsunamigenic hypothesis of these perturbations, we use a 3D numerical modeling of the ocean-atmosphere coupling, to reproduce the tsunami signature observed in the airglow by the imager located in Hawaii and clearly showing the shape of the modeled IGW. The agreement between data and synthetics not only supports the interpretation of the tsunami-related-IGW behavior, but strongly shows that atmospheric and ionospheric remote sensing can provide new tools for oceanic monitoring and tsunami detection. Key words: Internal gravity waves, tsunami, airglow, numerical modeling.
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