Tsunami Dynamics Research Articles

Tsunami waves of seismic origin: The modern state of knowledge

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

Técnicas histórico-etnográficas en la reconstrucción y caracterización de tsunamis: el ejemplo del gran tsunami del 22 de junio de 1932, en las costas del Pacífico mexicano

The magnitude of damage caused by tsunamis in the past decade has encouraged scientists to expand our knowledge about tsunami dynamics and behavior. This study applies a multidisciplinary analysis, including historical and ethnographic techniques, in the reconstruction and characterization of tsunamis with no instrumental record. The example of the 22 June 1932 tsunami, the second most destructive recorded in the Pacifi c Coast of Mexico is used. The cause of this tsunami is uncertain. Two hypotheses are proposed: 1) seismic slip, and 2) a submarine landslide. Historical archives, interviews with local witnesses, and GIS mapping, aided in identifying key components of the tsunami dynamics: arrival time, directivity, affected area, and maximum wave heights at the coast. Based on historical data, we applied numerical models (GEOWAVE and FUNWAVE codes) to the two possible mechanisms of tsunami generation. The results show that a submarine landslide explains best the cause of the 1932 tsunami.

A Revised Evaluation of Tsunami Hazards along the Chinese Coast in View of the Tohoku-Oki Earthquake

Japan's 2011 Tohoku-Oki earthquake and the accompanying tsunami have reminded us of the potential tsunami hazards from the Manila and Ryukyu trenches to the South China and East China Seas. Statistics of historical seismic records from nearly the last 4 decades have shown that major earthquakes do not necessarily agree with the local Gutenberg-Richter relationship. The probability of a mega-earthquake may be higher than we have previously estimated. Furthermore, we noted that the percentages of tsunami-associated earthquakes are much higher in major events, and the earthquakes with magnitudes equal to or greater than 8.8 have all triggered tsunamis in the past approximately 100 years. We will emphasize the importance of a thorough study of possible tsunami scenarios for hazard mitigation. We focus on several hypothetical earthquake-induced tsunamis caused by Mw 8.8 events along the Manila and Ryukyu trenches. We carried out numerical simulations based on shallow-water equations (SWE) to predict the tsunami dynamics in the South China and East China Seas. By analyzing the computed results we found that the height of the potential surge in China's coastal area caused by earthquake- induced tsunamis may reach a couple of meters high. Our pre- liminary results show that tsunamis generated in the Manila and Ryukyu trenches could pose a significant threat to Chinese coastal cities such as Shanghai, Hong Kong and Macao. However, we did not find the highest tsunami wave at Taiwan, partially because it lies right on the extension of an assumed fault line. Furthermore, we put forward a multi-scale model with higher resolution, which enabled us to investigate the edge waves diffracted around Taiwan Island with a closer view.

ビデオ画像解析に基づく綾里湾白浜海岸に集中した津波外力場特性の分析

ビデオ画像解析に基づく綾里湾白浜海岸に集中した津波外力場特性の分析

On the propagation of tsunami waves, with emphasis on the tsunami of 2004

In this review paper we discuss the range of validity of nonlinear dispersiveintegrable equations for the modelling of the propagation of tsunami waves. For the 2004tsunami the available measurements and the geophyiscal scales involvedrule out a connection between integrable nonlinear wave equations and tsunami dynamics.

Tsunamis

Purpose – Tsunamis are a rare but devastating form of natural disaster that has been documented since early civilization. Throughout history, many major tsunamis have impacted on the world's coastlines, causing heavy loss of lives and damage to properties. While the Sumatran tsunami in December 2004 demonstrated the sheer scale of destruction, there remains little understanding of the implications such obliteration have for disaster planning and management in the construction industry. The purpose of this paper is to raise the awareness of these implications and address some of the pertinent issues. Design/methodology/approach – The threat from tsunamis for an island state like Singapore cannot be ignored. A general study of tsunami dynamics is carried out and applied to model the worst scenario if tsunamis were to hit Singapore. Unique problems relating to such a scenario are subsequently highlighted to extrapolate an understanding of how the construction industry should now react even before the disaster strikes. Findings – There appear to be some potential danger and immense uncertainties to the immediate coastline of Singapore in the event of a tsunami. Faced with these uncertainties, the local construction industry needs to recognise such challenges and develop appropriate policies and strategies way ahead to account for disaster planning and management. Practical implications – While tsunami warning systems have been put in place, tsunamis cannot be stopped. The construction industry has a significant role to play in minimising destruction through appropriate building codes, materials, designs, enforcement and preventive maintenance of infrastructure. Originality/value – The paper raises the issues of disaster planning and management caused by tsunamis and prompts the construction industry into taking appropriate and timely action to ward off what can be an extremely threatening event to both lives and properties.

"Tsunami: The Underrated Hazard" by Edward Bryant

In Tsunami: The Underrated Hazard (Cambridge University Press, 2001), Edward Bryant proposes “to cover all aspects of modern tsunami research.” This is a monumental task that covers many disciplines: hydrodynamics, oceanography, geomorphology, sedimentology, engineering, seismology, numerical modeling, social sciences, and more. The book should be a welcome addition to the academic literature, as tsunami research has experienced a burst in the past two decades, driven by advances in numerical modeling, recent damaging tsunamis, paleoseismological studies of prehistoric tsunami events, and reassessment of tsunami sources and global tsunami risk. The book is intended to bring the reader “up to steam” in all these areas; unfortunately, it falls short of the mark. The book is attractive with many photographs and figures that are well laid out with respect to the text. At first glance, the scope is indeed comprehensive. There are four main sections: “Tsunami as Known Hazards” (legends, tsunami dynamics and wave theory, and run-up and inundation), “Tsunami-formed Landscapes” (tsunami deposits, erosional features, and landscape evolution), “Causes of Tsunami” (earthquakes, landslides, volcanism, impacts), and finally “Modern Risk of Tsunami” (risk, warning systems, scenario events). Unfortunately, the book is riddled with problems. The foremost is the failure to integrate the many different topics and disciplines into a coherent whole. Bryant has attempted to cover so many different research areas that many sections seem unrelated or even contradictory. The 1946 Aleutian earthquake …