Apocalyptic Tsunamis in Sumatra and Japan

The Sumatra tsunami of 2004 and the Tōhoku tsunami of 2011 were unprecedented disasters. Both were caused by large earthquakes in subduction zones. They shocked the world. This chapter explains how a tsunami is generated, why it is harmless and unnoticeable in the open ocean, and why it can become a devastating threat on a coast. Nearly 230,000 people died in the 2004 tsunami, tens of thousands because of the ignorance of politicians and local authorities and a lack of basic education. Science was also largely ignored in Japan. The accident at the Fukushima nuclear power plant was not necessary.