Why tsunami easily occur in indonesia?

Answer 1

Because around Indonesia there are a lot of unstable fault lines under the sea where Earthquakes happen regularly. Every now and then one of these Earthquakes is massive, causing a tsunami.

The boxing day tsunami was caused by an Earthquake of 9.3 or so off the West coast of Sumatra- it was the second largest Earthquake ever recorded.

Answer 2

Millions of years ago India and an ancient ocean called the Tethys Ocean were sat on a tectonic plate. This plate was moving northwards towards Asia at a rate of 10 centimeters per year. The Tethys oceanic crust was being subducted under the Asian Continent. The ocean got progressively smaller until about 55 million years ago when India 'hit' Asia. There was no more ocean left to lubricate the subduction and so the plates welled up to form the High Plateau of Tibet and the Himalayan Mountains. The continental crust under Tibet is over 70 kilometers thick. North of Kathmandu, the capital of Nepal, is a deep gorge in the Himalayas. the rock here is made of schist and granite with contorted and folded layers of marine sediments which were deposited by the Tethys ocean over 60 million years ago.

Underground volcanoes were born near Indonesia in effect of this tectonic plates crushing together. The fault lines near these plates made them active in under ocean volcanoes to explode from the building pressure made thousands of years ago. Despite from it all the Philippine plate (at the Ring of Fire fault lines) crushes on opposite directions to the Indian plate and Indonesia is at the center from it all. In theory, it is only now that those pressures are released creating those tsunamis--after the pressure is released, earthquakes and volcanic activities may subside.

Answer 3

Indonesia lies along the vocanically and tectonically active 'ring of fire' which surrounds the pacific ocean. The recent tsunamis are being caused by undersea earthquakes. It just happens that that area of the earth's crust is being particularly active right now. More earthquakes at the bottom of the ocean = more tsunamis.