Tsunami Generation And Propagation

This book introduces a framework of tsunami modelling from generation to propagation, aimed at application to the new observation started in Japan after the devastating tsunami of the 2011 Tohoku-Oki earthquake. About 150 seismic and tsunami sensors were deployed in a wide region off the Pacific coast of eastern Japan in order to catch tsunami generation inside the focal area, which makes a clear departure from conventional observations that detect tsunamis far from the source region. In order to exploit the full potential of this new observation system, it is not enough to model tsunami generation simply by static sea-bottom deformation caused by an earthquake. This book explains dynamic tsunami generation and sea-bottom deformation by kinematic earthquake faulting, in which seismic and acoustic waves are also included in addition to static sea-bottom deformation. It then systematically derives basic tsunami equations from the fundamental equations of motions. The author also illustrates the details of numerical schemes and their applications to tsunami records, making sound linkages among these topics to naturally understand how a tsunami is physically or mathematically described. This book will be a comprehensive guide for graduate students and young researchers to start their research activities smoothly.

A tsunami is a natural disaster characterized by a sequence of swiftly moving waves in the ocean, triggered by volcanic eruptions, strong earthquakes, or landslides inside the ocean. They are mainly generated by tectonic dislocations beneath the sea that result from shallow focus earthquakes along the zones of subduction. Tsunamis propagate through the full depth of the ocean from the surface to the floor. They have long wavelengths and have the capability of destroying trees, removing sand from beaches, dragging and tossing houses, vehicles and even destructing entire cities and towns. Tsunami modeling acts as an essential instrument for evaluating the possible effects of tsunami on the target shoreline in relation to all the earthquake scenarios that are considered in the earthquake model. This book aims to shed light on tsunamis, their generation, propagation, effects and modeling. With its detailed analyses and data, it will prove immensely beneficial to professionals and students involved in this area at various levels.

Till the very end of the twentieth century tsunami waves (or ‘waves in a harbour’, translated from Japanese) were considered an extremely rare and exotic natural p- nomenon, originating in the ocean and unexpectedly falling upon the seaside as gigantic waves. The 26th of December 2004, when tsunami waves wiped out, in a single day, more than 250,000 human lives, mourned in many countries, turned out to be a tragic date for all mankind. The authors of this book, who have studied tsunami waves for many years, - tended it to be a systematic exposition of modern ideas concerning • The mechanisms of tsunami wave generation • The peculiarities of tsunami wave propagation in the open ocean and of how waves run-up beaches • Methods for tsunami wave registration and the operation of a tsunami warning system • The mechanisms of other catastrophic processes in the ocean related to the se- mic activity of our planet The authors considered their main goal to be the creation of book prese- ing modern knowledge of tsunami waves and of other catastrophes in the ocean to scienti?c researchers and specialists in geophysics, oceanography, seismology, hydroacoustics, geology, geomorphology, civil and seaside engineering, postgr- uate students and students of relevant professions.

This book presents two distinct aspects of wave dynamics – wave propagation and diffraction – with a focus on wave diffraction. The authors apply different mathematical methods to the solution of typical problems in the theory of wave propagation and diffraction and analyze the obtained results. The rigorous diffraction theory distinguishes three approaches: the method of surface currents, where the diffracted field is represented as a superposition of secondary spherical waves emitted by each element (the Huygens–Fresnel principle); the Fourier method; and the separation of variables and Wiener–Hopf transformation method. Chapter 1 presents mathematical methods related to studying the problems of wave diffraction theory, while Chapter 2 deals with spectral methods in the theory of wave propagation, focusing mainly on the Fourier methods to study the Stokes (gravity) waves on the surface of inviscid fluid. Chapter 3 then presents some results of modeling the refraction of surf ace gravity waves on the basis of the ray method, which originates from geometrical optics. Chapter 4 is devoted to the diffraction of surface gravity waves and the final two chapters discuss the diffraction of waves by semi-infinite domains on the basis of method of images and present some results on the problem of propagation of tsunami waves. Lastly, it provides insights into directions for further developing the wave diffraction theory.

The Tsunami from the 1960 Chilean earthquake affected the entire Pacific Ocean and motivated the international coordination on tsunami research and warning systems around the Pacific. However, the 2004 Indian Ocean tsunami affected the entire world, and reminded that tsunamis are not a local or regional problem but a global issue. This volume contains 18 papers, mostly presented at the 24th International Tsunami Symposium held in 14-16 July 2009. They reflect the current state of tsunami science, including case studies of earthquake-generated tsunamis, tsunami forecasting and hazard assessments, and theoretical and computational modeling of tsunami generation, propagation and coastal behavior.