Characteristics Of Tsunamis Research Articles

Characteristics of Earthquake-Generated Tsunamis in Indonesia Based on Source Parameter Analysis

We have characterized 27 earthquake-generated tsunamis from 1991 to 2012 in Indonesia, based on source parameter analysis. This includes the focal mechanism derived by W phase inversion analysis, the ratio ( Θ ) between the seismic energy ( E ) and the seismic moment ( Mo ), the moment magnitude ( Mw ), the rupture duration ( To ) and the distance of the hypocenter to the trench. Most of the earthquakes (24 events) were tsunamigenic earthquakes with various fault types, a shallow focal depth (12 km ≤ D ≤ 77.8 km), a small to large magnitude (6.6 ≤ Mw ≤ 9.0), a low ratio of seismic energy to seismic moment (-5.8 < Θ < -4.9), a short to long rupture duration (27 s ≤ To ≤ 257 s), a small to large tsunami height (0.1 m ≤ H ≤ 50.9 m) and a short to long distance from the hypocenter to the trench (10 km < HT ≤ 230 km). Three tsunami earthquakes were characterized by a thrust fault mechanism, a very shallow depth ( D ≤ 20 km), a moderate magnitude (7.5 ≤ Mw ≤ 7.8), a very low ratio of seismic energy to seismic moment ( Θ ≤ -5.8), a long rupture duration (99 s ≤ To ≤ 135 s), a large tsunami height (7.4 m ≤ H ≤ 14 m) and a short distance from the hypocenter to the trench ( HT ≤ 20 km).

河川津波の特性把握に関する実験的検討

河川津波の特性把握に関する実験的検討

실용적인 원지 지진해일 예경보 체계

본 연구에서는 우리나라 실정에 부합되는 실용적인 원지 지진해일 예경보 체계 구축을 위해 미국과 우리나라의 지진해일 예경보 체계 현황을 파악하고, 2011년 동일본 지진해일 당시의 대처상황을 분석하였다. 우리나라 해안 지역에 영향을 미치는 원지 지진해일의 발생원 및 전파 특성을 고려하고, 지진탐지 및 수치모의수행 능력과 가용 전문인력 등을 고려한 효율적인 원지 지진해일 예경보 체계 구축 방안을 제안하였다. To construct the practical forecast and warning system for distant tsunamis suitable for Korea the state-of-art of the forecast and warning systems of United States and Korea is investigated, and the action conducted by Korea for the case of 2011 East Japan Tsunami is also analysed. The tsunami sources and propagation characteristics of distant tsunamis that affect the Korean coastal area are considered along with the capability of earthquake monitering and numerical simulation and the available experts to propose the effective forecast and warning system for distant tsunamis.

津波の基本特性と東北地方太平洋沖地震による津波災害

津波の基本特性と東北地方太平洋沖地震による津波災害

육상저유탱크 및 육상가옥에 작용하는 지진해일파력의 추정

본 연구에서는 육상구조물에 작용하는 지진해일파력해석을 위하여 Navier-Stokes slover에 기초한 3차원 혼상류수치해석법을 적용하여 검토하였다. 여기서, 대상구조물을 육상저유탱크와 육상가옥으로 하여 호안과 육상구조물간의 이격거리에 따라 육상구조물에 작용하는 지진해일파력을 검토하였다. 또한 육상구조물에 작용하는 지진해일 파력의 추정을 위하여 항력만을 고려한 방법과 항력 및 관성력을 동시에 고려한 방법을 각각 적용하여 얻은 결과와 수치해석결과 및 설계기준에 의한 결과치를 비교 분석하였다. 이로부터 항력 및 관성력을 동시에 고려하여 추정한 지진해일파력이 항력만을 고려한 경우 보다 수치해석결과에 더 근접하는 것을 확인하였다. This study investigated the tsunami force acting on onshore structures using a numerical program, three-dimensional one-field model for immiscible multi-phase flows, which is based on Navier-Stokes solver. In this paper, the characteristics of tsunami of oil storage tank and house structures studied to the distance between the seawall and structure. In addition, the study compared and analyzed the tsunami forces determined by considering drag force only and considering both drag and inertia forces. These numerical results were compared with the design standard. As a results, the case of considering the both forces is more close to numerical result than that of considering the drag force only.

Tsunamis versus storm deposits from Thailand

Along the Andaman (west) coast of Thailand, the 2004 tsunami depositional features associated with the 2004 tsunami were used to describe the characteristics of tsunamis in a place far away from the effect of both recent and ancient storms. The current challenge is that a lack of precise sedimentological characteristics have been described that will differentiate tsunami deposits from storm deposits. Here, in sedimentological senses, we reviewed the imprints of the sedimentological characteristics of the 2004 tsunami and older deposits and then compared them with storm deposits, as analyzed from the deposits found along the eastern (Gulf of Thailand; GOT) coast of Thailand. We discuss the hydraulic conditions of the 2004 tsunami and its predecessors, on the Andaman coast, and compare them to storm flows found on the coast of the GOT. Similar to an extensive tsunami inflow deposit, a storm flow overwash has very similar sedimentary structures. Well-preserved sedimentary structures recognized in sand sheets from both tsunami and storms include single and multiple normal gradings, reverse grading, parallel, incline and foreset lamina, rip-up clasts, and mud drapes. All these sedimentary structures verify the similarity of tsunami and storm inflow behavior as both types of high-energy flow start to scour the beach zone. Antidunes are likely to be the only unique internal sedimentary structures observed in the 2004 tsunami deposit. Rip-up clasts are rare within storm deposits compared to tsunami deposits. We found that the deposition during the outflow from both tsunami and storms was rarely preserved, suggesting that it does not persist for very long in the geological record.

Numerical modeling of the propagation and strengthening of tsunami waves near the Crimean Peninsula and the Northeast Coast of the Black Sea

The linear model of long waves is used for the evaluation of the parameters of tsunami waves along the South Coast of Crimea, in the near-Kerch zone, and near the northeast coast of the Black Sea. Our numerical investigations are carried out for 24 probable locations of the elliptic zones of tsunami generation over the continental slope of the basin. The amplitude characteristics of tsunamis are computed for 27 sites of the Black-Sea coast. It is shown that significant strengthening of tsunami waves is possible in the course of their propagation toward the coast. The highest waves are formed at the sites of the coast closest to the seismic source. The dependence of the intensity of tsunami waves along the Black-Sea coast on the location of the seismic source and its magnitude is analyzed.

Tsunami hazard and early warning system in South China Sea

In this paper, we discuss the potential tsunami hazard in the South China Sea region. We focus our discussions on the characteristics of tsunamis generated from earthquakes along the Manila subduction zone. A procedure is presented for establishing a tsunami early warning system in the region. A scenario case is used to demonstrate the feasibility of the early warning system.

Historical tsunamis and storms recorded in a coastal lowland, Shizuoka Prefecture, along the Pacific Coast of Japan

AbstractFour sand units deposited by tsunamis and one sand unit deposited by storm surge(s) were identified in a muddy marsh succession in a narrow coastal lowland along the Pacific coast of central Japan. Tsunamis in ad 1498, 1605, 1707 and 1854 that were related to large subduction‐zone earthquakes along the Nankai Trough, and storm surges in 1680 and/or 1699 were responsible for the deposition of these sand units. These sand units are distinguished by lithofacies, sedimentary structures, grain‐size and mineral composition, and radiocarbon ages; their ages are supported by events in local historical records. The tsunami deposits in the study area are massive or parallel‐laminated sands, with associated intraclasts, gravels, draping mud layers and, rarely, a return‐flow subunit. The storm surge deposits are devoid of these characteristics, and are composed of groups of thin, current ripple‐laminated sand layers. The differences in sedimentary structures between the tsunami and storm surge deposits are attributed to the different characteristics of tsunami and storm waves.

Propagation characteristics of historical tsunamis that attacked the east coast of Korea

In this study, a numerical modeling system based on the dispersion–correction finite difference scheme equipped with a grid-nesting scheme is constructed. The model is applied to simulate the propagation of three historical tsunami events that attacked the east coast of Korea. The calculated free-surface displacements for the cases of the 1983 Akita and the 1993 Okushiri tsunamis are compared with the observations at four tidal stations along the east coast of Korea. The comparison shows that the results agree well with the observations. The analyses of the simulated results show that underwater topography, such as submerged rises and ridges, plays an important role in the propagation of tsunamis in this region.

Numerical Analysis of the Later-phase Tsunami Accompanied with Earthquakes along the Kuril Trench

We discuss the characteristics of the later-phase tsunamis accompanied with earthquakes along the Kuril trench, based on the numerical modeling of trans-oceanic tsunamis and the analysis of observed tsunami waveforms. The model results suggest that the later-phase tsunami is caused by edge waves or scattering waves from the seamounts, depending on the tsunami source location; tsunami energy radiated from south of 46° N can result edge waves andnorth of 46° N to 49°N can be scattering waves. Also, we found that analyzing the time evolution of Fourier spectra of observed tsunami waveforms can identify the cause of later-phase tsunamis and can be used to decide the timing of tsunami warning cancellation after it's issued.

Runup and Inundation along the Indian Peninsula, Including the Andaman Islands, due to Great Indian Ocean Tsunami

The December 2004 Sumatra earthquake triggered massive tsunami waves in the Indian Ocean and the Bay of Bengal. The tsunami waves traveled primarily in the east-west direction and caused major damage along the coasts of southern India, Sri Lanka, Thailand, and Indonesia. It has proved to be the most disastrous tsunami in recorded history, and scientists and engineers around the world set out to record signatures of the tsunami from which the characteristics of the tsunami waves at the time of landfall could be deciphered. Such information is extremely useful in validating mathematical models for understanding the characteristics of tsunamis and their effects along the coast. The writers conducted surveys along the east and west coasts of peninsular India—focusing on the states of Tamil Nadu and Kerala and around Andaman and Nicobar Islands, where the devastation caused by the tsunami was unparalleled. The analysis of data gathered during the post-sunami survey focused on consolidating the primary paramete...

Principles of numerical modeling applied to the tsunami problem

[2] In our paper, we formulate the principles of using computational tools to solve applied problems of tsunami oriented to the support of decisions by managers in critical situations [Shokin and Chubarov, 1999]. [3] From hereon we shall use term “tsunami” to denote the entire complex of catastrophic impacts caused by the waves in the basins and adjacent territories of the coast. The nature and spectral characteristics of these waves are usually associated with long surface gravity tsunami waves. [4] Similarly to other natural and anthropogenic catastrophes, tsunamis pass three stages in their development: stage before crisis, crisis, and stage after crisis. [5] Each of these stages is characterized by its duration, spatial scale, localization, and specific impact on the population involved in the crisis. Each stage requires specific methods of control and formulation of the list of problems, the important place in the solution of which is occupied by the methods of computational modeling. Specific limitations are imposed on mathematical models, numerical algorithms, technologies of calculation, character and volume of the results, means of their presentation (including visualization) means, protocols, and addressing of their spreading. [6] Leaving a number of provisions formulated above without consideration for a certain period of time we shall discuss the requirements, which the computational tools should satisfy. These tools are allowed by the scientific community for determining the vital characteristics of tsunami that are impossible or difficult to obtain using alternative sources (field

Implications of the seismic source dynamics for the characteristics of a possible tsunami in a model problem of the seismic gap in the Central Kurile region

Implications of the seismic source dynamics for the characteristics of a possible tsunami in a model problem of the seismic gap in the Central Kurile region

Modeling the 2004 Indian Ocean Tsunami for Introductory Physics Students

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

Estimates of Tsunami Risk Zones on the Coasts Adjacent to the East (Japan) Sea based on the Synthetic Catalogue

Prognostic characteristics of tsunamis in the East (Japan) Sea based on numerical simulations are investigated by using linear long wave theory. Due to the lack of observed data, the concept of the synthetic catalogue is applied to generate possible tsunami scenarios. It includes four real events that occurred in the East (Japan) Sea during the 20th century, 24 hypothetical tsunamigenic earthquakes located in the gap zones of the seismic map, and 76 idealized model ‘hydrodynamic’ sources covering the eastern part of the East (Japan) Sea uniformly. The tsunami wave height distributions along the East (Japan) Sea coastline due to these hypothetical events are computed. From the geographical distributions of tsunami wave height for all possible events, it is found that there exist several coastal locations where the tsunami risk is relatively lower than in other zones. The relation between the maximal value of the tsunami height and its average value is analyzed. It is found that the maximal tsunami height does not exceed the mean wave height times a constant. The uniform bounded curve for all areas can be obtained if the mean wave height is replaced by the modified mean wave height (1/3 of largest waves). The problem of quantitative definition of the prognostic tsunami wave height for each location based on the data from the synthetic catalogue is discussed. The results of tsunami wave height analysis based on the synthetic catalogue can be used as a tool for coastal disaster mitigation planning.

NUMERICAL STUDY ON THE PROPAGATION OF TSUNAMI IN RIVERS

Tsunami waves in river channel typically form undular bore to ascend the channel. The undular bore can not neglect the acceleration of vertical direction, so that the nonlinear dispersive wave theory can be applied to the governing equation. In this paper, the equation was used to conduct numerical experiments in order to investigate the propagation characteristics of tsunami in the river channel. The experiments were conducted by varying parameters which were Froude number of steady flow in river, bottom friction, the slope of the river bed and incident waveform of tsunami. As a result of the experiments, the following useful knowledge was obtained. The river channel topography is likely to induce the wave dispersion, and this tendency increases with decrease in the bed slope. The high hazardous reach by the infiltration of tsunami is almost same from river mouth despite the bed slope.

공백역 지진에 의한 동해에 연한 해안에서의 지진해일 위험도 산정

전회의 논문(Choi et al)에 이어 본 논문에서는 동해에서의 가상해저지진에 의한 지진해일의 예단적 특성을 동해에 연한 전해안에 걸쳐 논하였는데 재해를 유발시킬 수 있는 지진해일의 근원역은 공백역이론으로부터 선택되었다. 선형장파이론에 근거한 수치모형을 채택하여 28개의 선정된 자세한 단층 파라미터를 갖는 가상지진(4경우 실제지진 포함)과 단순화시킨 형태의 초기 수면형에 의한 76개 사상의 지진해일 시뮬레이션을 수행하여 전파 및 해안에서의 지진해일의 파고를 산정하는 데 적용 되었다. 결과로서 동해에 연한 전해안 전역에 전파되는 지진해일의 특성과 해안역에서의 지진해일의 파고 분포가 산정되어 지진해일 재해위험도가 상대적으로 낮은 지리적 위치를 구획화하여 제시함으로써 해안재해경감대책의 도구로서 활용될 수 있게 하였다. Prognostic characteristics of hypothetical tsunamis in the East Sea are further discussed based on numerical simulations using linear long wave theory than the last paper(Choi et al). As for choice of source zones, we used 28 cases based on fault parameters of hypothetical earthquakes and 76 cases based on simple initial surface shapes of tsunamigenic earthquakes selected by the seismic gap theory. As a result, the wave heights along the whole coastline adjacent to the East See of tsunamis due to these hypothetical earthquake are presented. Analyses also lead us to conclude that the selection of geographical zones with low risk of tsunamis can be used as a tool for coastal disaster mitigation planning.

공백역 지진에 의한 동해안의 지진해일 산정

본 논문에서는 동해에서의 가상해저지진에 의한 지진해일의 예단적 특성에 대해 논하였는데 재해를 유발시킬 수 있는 지진해일의 근원역은 공백역이론으로부터 선택되었다. 선형장파이론에 근거한 수치모형과 구면좌표계상의 파향선방정식에 근거한 파향선추적산정모형을 채택하여 28개의 선정된 가상지진(4 경우 실제지진 포함)에 의한 지진해일 전파를 산정하는 데 적용되었다. 결과로서 동해안에 전파되는 지진해일 특성과 동해안의 해안역위치에서의 지진해일 분포가 산정되어 지진해일 재해위험도가 상대적으로 낮은 지리적 위치를 구획화하였다. Prognostic characteristics of hypothetical tsunamis in the East Sea are discussed based on numerical model simulations of linear long wave theory and wave ray for 28 source zones of tsunamigenic earthquake selected by the seismic gap theory. As a result, the propagation patterns of tsunamis due to hypothetical earthquake are presented and analyses also lead to selection of the geographical zones with low risk of tsunamis.

Simulation of prognostic tsunamis on the Korean Coast

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.