The December 26, 2004 Indian Ocean tsunami, triggered by a massive earthquake off the coast of Sumatra, is the deadliest natural disaster ever of this kind. Aside from a massive number of casualties, this tsunami caused heavy economic damage and severe destruction to the natural environment of stricken countries. Given the significant destruction and suffering, it resulted in massive international support through financial and humanitarian aid. The purpose of this paper is to provide an analysis and a better understanding of the causes, the impacts and actions that could have been taken to limit the damage. Introduction
The December 26 2004 Indian Ocean Tsunami ranks among the ten deadliest natural disasters ever recorded thus far with a death toll over 225 000 and thousands of individuals missing. The large tsunami waves were generated by a massive earthquake off the northwest coast of Sumatra Island in Indonesia (Rossetto 2007). Tsunami waves spread across the Indian Ocean, damaging the shores of countries near and far from the epicenter (Rossetto 2007). It produced considerable damage and its impact went beyond the toll of human casualties. It had widespread economical, environmental and psychological impacts. Among the worst hit regions were the countries in and around the eastern Indian Ocean. Such natural disaster causes tremendous human suffering and immediately solicited responses worldwide with significant financial support and humanitarian aid.
Sequences of Events (Earthquake & Tsunami)
The 9.0 magnitude earthquake of 26 December 2004 that occurred off the northwest coast of Sumatra in Indonesia was the third largest earthquake ever recorded. With an epicenter located near the Indonesian island of Sumatra, the quake was generated as a result of the sliding of a portion of the India plate beneath the Burma plate (Risk Management Solution, 2006). The result was a fault rupture, displacing the seafloor (Figure 1) and a large volume of the ocean, triggering devastating waves that hit the coastline of 11 Indian Ocean countries (Bilham 2005). The tsunami waves travelled across the Indian Ocean with an average velocity of 640 km/h (Rossetto 2007). However, tsunami waves tend to behave differently in deep water than in shallow water (Rossetto 2007). Once the tsunami reaches shallow water along the coastline, the wave velocity decreases while its amplitude increases significantly from the mass amount of energy built by the wave, causing even more destructive waves and substantial inland inundation (Rossetto 2007). In Aceh, north of the island of Sumatra, wave height reached 24 meters once it hit the shores and rose up to 30 meters inland, with a maximum wave height recorded to be 60 meters (Paris 2007).
Being the landmass closest to the epicenter of the earthquake, Aceh province was the hardest hit area from the eastward-moving tsunami followed by Sri Lanka because of non-existing landmass between it and the epicenter of the quake to protect the coastlines (Athykorala 2005). The fault rupture of the earthquake was in a north-south orientation, which meant that the strength of the tsunami was greatest in east-west direction (Athykorala 2005). Hence, despite being located near the epicenter, some regions escaped the worst from the tsunami given their position relative to the fault rupture. With this said, Somalia was hit harder than Bangladesh despite being farther away from the epicenter (Athykorala 2005). Depending on the distances involved, the tsunami could propagate up to hours before reaching some coastlines. Aceh, Nicobar and Andaman were among the first regions to feel the effect of the tsunami, eventually hitting coastal regions of Thailand, Myanmar, India, Sri Lanka, Maldives, Somalia, Kenya and Tanzania (Figure 2). At last, its effects were also detected along the west coast of North and South America, which includes Vancouver and British Columbia.
A tsunami is...