Understanding of the Sumatran subduction zone and its hazards has increased since the 2004 Indian Ocean earthquake and tsunami.

The powerful earthquake off the coast of the Indonesian island of Sumatra on Dec. 26, 2004, triggered a tsunami that impacted a dozen countries, reaching as far as East Africa.

The earthquake and tsunami claimed the lives of over 200,000 people, the deadliest natural disaster of the 21st century.