What is Tsunami?

Inspite of all the technological advances humans can boast,mankind is still at the mercy of Nature.This was proved and the world tasted the consequences of Nature's fury this sunday.
What is a "Tsunami"? in Japanese "Tsunami" means "Large sea waves".Tsunamis are huge tidal waves tht can sometime rise as high as 10m...Pacific region is not a stranger to tsunamis....But south asia was certainly an absolute stranger to this phenemenon caused by seismic activity under water bodies...to chk out wht causes a tsunami..click on the following
Tsunamis de-mystified!

There is news abt the change of India's coastline as well..
Tsunamis change the coastline