On December 26, 2004, a devastating tsunami struck the Indian Ocean. Tsunamis occur when an undersea earthquake causes a large displacement of water. Waves surged ashore in Indonesia, Sri Lanka, India, Thailand, Maldives and elsewhere, causing immense damage and loss of life. Some of the effects of the tsunami occurred within moments of the wave hitting, while others are still being felt.
Loss of life
Waves up to 30m (over 98 feet) high crashed ashore in some countries. People in coastal communities were drowned or killed as the waves knocked down buildings, capsized vessels and swept vehicles off the roads. Estimates vary, but over 180,000 people are known to have been killed. Although many of the tsunami's victims were located and buried, some remain unaccounted for. Indonesia's Aceh province was the hardest-hit region, with over 200,000 people dead or missing.
In addition to killing hundreds of thousands in coastal areas, the tsunami destroyed many homes and rendered many more unusable. According to a study published in "Emergency Medicine International," over 1.7 million people were displaced from their homes by the wave. Some islands in the Indian Ocean lost their only sources of fresh water as seawater flooded into their aquifers. Emergency response systems were overwhelmed, and the international community stepped in to provide aid. Over 750,000 people in Sri Lanka needed assistance from the UN's World Food Programme.
The tsunami inflicted severe damage not only on human settlements but also on the ecosystems of the region. The force of the wave killed marine life as well as plants and animals on land. Sediment was stripped from marine habitats and deposited on land, while huge quantities of salt water flooded into bodies of fresh water. In some cases, damage to storage facilities that held toxic wastes, sewage, fuel and other pollutants released these substances into the environment.
Some countries affected by the 2004 tsunami were not hit until hours after the earthquake that caused it. Nevertheless, these regions were taken completely by surprise. In 2004, the Indian Ocean region lacked a central tsunami warning system, meaning that vulnerable populated areas could not be evacuated or prepared for the disaster. In 2005, a UN conference established a new international tsunami warning system for the region; it became operational in 2006.