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

Christmas in 2004, a 9.1 magnitude earthquake under the Indian Ocean triggered tsunami waves that killed some 230,000 people across a dozen countries.

Thursday marks the 20 th anniversary of the 2004 Indian Ocean tsunami, one of the deadliest natural disasters ... with more than 170,000 people killed. In Thailand, beach resort tourists comprised about half of the nation’s death toll of 5,000, while ...