Tsunamis: Alert, prepare and understand—20 years of action

On 26 December 2004, a massive earthquake measuring a magnitude of 9.1 struck off the coast of the Indonesian island of Sumatra, causing the deadliest tsunami in history. More than 227,000 people lost their lives across 15 countries, with over 1.6 million people displaced. The highest death toll, over 167,000, was reported in Banda Aceh and Meulaboh along the northwestern coast of Sumatra. Economic losses were more than $10 billion across the region.

Understanding tsunami hazards can save lives. UNESCO works to prepare the 700 million people living in at-risk coastal areas across the globe by organizing tsunami preparedness exercises, response plans and drills across all the ocean basins. This brief offers an overview of the actions made since the 2004 earthquake and tsunami to improve early warning, risk management, and resilience against tsunamis.