By : Ashutosh Mohanty, Ph.D.
(Co-Principal Investigator & Researcher)
Sidhya Brat Dash, M.A,L.L.B
(
Project Coordinator)
Super Cyclone –99 Project 
Under :N.C.A.R, E.S.I.G., U.S.A

Introduction

The word ‘Tsunami’ is of Japanese origin, which means, “harbour wave”. Tsunami are large waves that are generated when the see floor is deformed by seismic activity, vertically displacing the overlying water in the ocean. The quake occurred at a place where several massive geological plates push against each other with massive force. Tsunami has very low height while traveling over deep ocean. High waves occur only when it reaches the shallow waters, typically near the coast. The mega thrust earthquake-measuring 9.0 at Richter scale, off the western coast of northern Sumatra (Banda Ache), Indonesia was the largest of its type since the 9.2 magnitude Good Friday earthquake off Alaska in 1964. The deadliest natural disaster caused by the tsunami generated from an undersea earthquake on 26 December 2004 in the Indian Ocean has shaken up the world. The 2004 tsunami generated waves of up to 15 meters in height and even hit Somalia at a distance of about 4500 km west of the epicenter. The tsunami traveled slowly and took seven hours to hit the farthest coast at the west. Because of the 1200 kilometer of the fault line affected by the seaquake was in a nearly north-south orientation, the greatest strength of the tsunami waves was in the east-west direction. 

The 2004 Indian Ocean earthquake was an undersea earthquake that occurred at 00:58:53 UTC (07:58:53 local time) on December 26, 2004. The earthquake originated in the Indian Ocean just north of Simeulue island, off the western coast of northern Sumatra, Indonesia. The resulting tsunamis devastated the shores of Indonesia, Sri Lanka, India, Thailand, and other countries with waves of up to 15 m (50 feet) high, even reaching the east coast of Africa, 4500 km (2,800 miles) west of the epicenter.The Unieted States Geological Survey recoreded the magnitude of the earthquake of Sumatra at 8.9 with the epicenter lying 10km below the seabed. Aftershocks struck in the magnitude 7 range. The quake occurred at a place where several massive geological plates push against each other with massive force. The survey said, a 1000 – kilometer section along the boundry of the plate shifted, a motion that triggered the sudden displacement of a huge volume of water. An interesting phenomenon of the seismic tidal waves in the different part of the world was that people saw sea water disappearing away from the beaches in the minutes before the giant wave lashed back with infernal fury devouring whatever come on the way of their lethal onslaught. Scientists say the effect is caused by tidal waves shocking shallow coastal waters out to see before returning them as a massive wall of water. 


The titanic tsunami that wrought unprecedented death and destruction in South and South-East Asia will go down in history as one of the greatest natural calamities of the modern times. The great disaster caught the people and the government off guard and in a matter of minutes, snuffed out more than 2,00,000 lives. Across the more than twelve countries. The number of people rendered homeless might run into millions, as no estimate is immediately available as to how many children have become orphans, how many women become widows and how many families have been wiped out in a single sweep.