Question

Why was the Indian Ocean tsunami so disastrous

Answer 1

The areas in the Indian ocean had a greater population and a less steep coastline. That makes for bigger waves and for the waves going farther ashore. Also, it was during a time of year when many people were on or near the beach and in a climate where many people live, play and work on the coast. The quake occurred in an area where the shock could ripple in many directions.