TSUNAMI

Case Study: Tsunami



Case Study: Tsunami

Introduction

Study of hazards involves the concepts of vulnerability, risks, and hazards, with hazards research evolving to include considerations of social vulnerability and resilience. Although public use of the words vulnerability, risk, hazard, and threat has sometimes been interchangeable, each word has its own specific definition within the field of hazards geography.Tsunami

The devastating tsunami in the Indian Ocean of December 26, 2004, alerted the world to one of the most terrifying natural phenomena on Earth. Few will forget the scenes of carnage and destruction wrought by the floodwaters as they swept across coastal areas. In fact, tsunamis known about for generations. The word tsunami derived from the Japanese word meaning “harbor wave.” Tsunamis often described as tidal waves; however, this view is erroneous, since they have nothing to do with tides. Tsunamis generated by offshore earthquakes, submarine slides, and, occasionally, sub aerial landslides that enter water bodies. Asteroid impact is an additional but much rarer mechanism (Wisner, 2004). With the exception of asteroid impacts, the displacement of mass, whether through submarine sediment slides, the collapse of a volcanic edifice, or an earthquake that induces faulting of the seabed, leads to a large-scale displacement of water. Although most tsunamis are phenomena associated with the open ocean, some tsunamis can be generated within lakes and/or fjords due to rockslide failures. An attempt made here to explain the processes of tsunami generation and propagation as well as what happens when tsunamis strike coastlines. A description given of how societies have responded to the perception of tsunami risk. (Hewitt, 1997)Natural and Technological Hazards

Building on these studies of flood hazards, the hazards field expanded to include not only a wide variety of geological, hydrological, and meteorological events but also many technological hazards, including those related to industrial and transportation accidents, releases of toxic chemicals and radiation, and pollution. At the same time, the study of hazards spread from American or European settings to less industrialized non-Western societies—although such studies remains in the minority. Hazards related to global warming are increasingly considered, and studies have considered the consequences of such warming on drought, wildfire, and hurricane hazards, among other hazard threats. (Cutter, 2001)

The tsunami caused by an offshore (undersea) earthquake of magnitude 9.2 that triggered along an area of plate collision where the India Plate, an oceanic plate, sub ducted beneath the Burma-Sunda plate across a subduction zone in the area of the Sunda Trench. The epicenter of the 9.0-magnitude quake was under the Indian Ocean off the western coast of Sumatra, Indonesia. The earthquake associated with the rupture of the seafloor along a length of 1,000 km (kilometers; 620 mi. [miles]). Along this zone, the land surface displaced both laterally and vertically by several meters. This event led to the sudden displacement of the overlying ocean water and the production of the tsunami.Vulnerability

Vulnerability to hazards varies depending on both the physical and the social setting of a community. Because vulnerability can be defined as the potential for and consequences of casualty or economic losses, it is not necessarily directly related to hazard risk or ...