Tsunami of 2004 was a massive natural disaster that occurred on Dec. 26, 2004, and killed about 228,000 people in coastal areas of Southeast Asia, South Asia, and East Africa. A tsunami is a series of huge ocean waves created by an earthquake or other natural force. The 2004 tsunami was the result of an extremely powerful undersea earthquake in the Indian Ocean, near the Indonesian island of Sumatra. The earthquake created tremendous waves that spread throughout the ocean and became towering walls of water as they reached coastal areas. Nearly all the affected areas had no warning of the tsunami before it hit. The waves rushed ashore and traveled far inland, destroying thousands of buildings and sweeping away boats and vehicles. The tsunami also left millions of people homeless.
Description of the disaster.
The earthquake occurred at 7:58 a.m. local time on December 26. Its focus or hypocenter—the point deep in Earth where it originated—was about 20 miles (32 kilometers) below the ocean surface. The epicenter—the point on Earth’s surface directly above the focus—was about 50 miles (80 kilometers) off the west coast of northern Sumatra. The quake was so powerful that it was difficult for scientists to precisely calculate its strength. According to the United States Geological Survey, the magnitude of the quake was 9.1, making it the strongest earthquake since 1964 (see Moment magnitude ). Researchers at Northwestern University in Illinois have calculated a 9.3 magnitude for the quake.
Energy from the earthquake jolted the seabed upward, displacing huge amounts of water and forming the waves of the tsunami. The waves moved through the ocean, away from the epicenter. In deep water, the waves traveled at up to 500 miles (800 kilometers) per hour. As the waves reached shallow water near coastal areas, they slowed down, but pushed upward. In some areas, the waves grew to heights of about 50 feet (15 meters) at the shore. Once the waves hit the shore, they surged over beaches and farmland and through cities, villages, and resort areas, causing death and destruction. In some places, the waves traveled far inland.
The tsunami spread throughout the Indian Ocean over the course of seven hours. It hit the western and northern coasts of Sumatra about 15 minutes after the earthquake occurred. Around 15 minutes later, it reached the Andaman and Nicobar Islands, a territory of India in the eastern Bay of Bengal. After another hour, the tsunami hammered the southwestern coast of Thailand, as well as parts of the western coasts of Myanmar and Malaysia. Roughly half an hour later, it slammed into the eastern and southern coasts of Sri Lanka and the eastern and southern coasts of the Indian mainland. The waves also wrapped around Sri Lanka and India, hitting the western Sri Lankan coast and the southwestern Indian coast. About 11/2 hours later, the tsunami swept over the islands of the Maldives, a low-lying country southwest of India. Finally, after another 31/2 hours, the tsunami reached the coast of East Africa, striking mainly Somalia but also parts of Kenya and Tanzania.
Scientists at the United States Pacific Tsunami Warning Center in Ewa Beach, Hawaii, detected the earthquake in the Indian Ocean. They believed, based on their measurements, that it might produce a tsunami. The center is part of a system of stations that monitor earthquakes in the Pacific Ocean in an effort to warn countries in the region of possible tsunamis. However, because there was no tsunami detection equipment in the Indian Ocean, and no organized tsunami warning system there, the U.S. scientists could not confirm a tsunami’s formation or issue a timely alert. As a result, the tsunami took people by surprise almost everywhere it hit.
The human cost.
In Indonesia, the country closest to the earthquake’s epicenter, the tsunami killed more than 165,000 people. Most of these fatalities occurred in the province of Aceh on the island of Sumatra. The waves swept away entire villages in Aceh. More than 35,000 people died in Sri Lanka, more than 16,000 in India, and more than 8,000 in Thailand. In India’s remote Andaman and Nicobar Islands, more than 3,500 people were killed as the waves destroyed coastal villages. In Somalia, the toll was about 300, and smaller numbers died in a number of other countries, including Malaysia, the Maldives, Myanmar, and Tanzania.
Most of the people killed were local residents. However, some of the hardest-hit areas were beaches and resort towns populated by tourists. About 40 countries from all over the world reported that some of their citizens perished in the disaster.
Hospitals and mortuaries were overwhelmed by the disaster. Hotels, temples, and outdoor areas were turned into temporary morgues. Many of the dead were buried in mass graves. Tens of thousands of children lost their lives, and many thousands of others were orphaned. Millions of people lost their homes in the disaster, and many packed into refugee camps. Initially, many health officials feared that epidemics of cholera, malaria, and other diseases could occur in some areas. Some isolated outbreaks of disease did occur. However, workers from government and international aid agencies were able to prevent diseases from spreading widely.
The economic and environmental costs.
The tsunami destroyed or damaged roads; bridges; water and sewerage systems; communication systems; and homes, hotels, schools, and other buildings. In the worst-affected areas, many people were left without water, food, or shelter. Great numbers of people lost their jobs or small businesses. Thousands of fishing boats were destroyed, dealing a severe blow to the many residents who depend on fishing for their livelihood. Crops were destroyed, and farm animals were killed.
The tsunami caused about $10 billion in damage to the region as a whole. In most countries, the effect on the overall economy was relatively small, in part because major cities and factories escaped damage. However, in areas that depend on tourism, such as the resort regions of Thailand, the south coast of Sri Lanka, and the Maldives, the economy was severely affected.
Salt water from the tsunami contaminated many sources of drinking water and ruined large areas of farmland. The tsunami damaged coral reefs, forests, and plant life. It also damaged fish habitats and caused coastal erosion and sewage contamination to groundwater.
The world’s response.
The governments of many countries, as well as private organizations and individuals, donated money, food, water, clothing, and medical supplies to the affected countries. Billions of dollars were donated or pledged from all over the world. Several countries, including India, the United States, and Australia, provided military troops, ships, and aircraft for the relief effort.
Following the disaster, experts developed a tsunami warning system for the Indian Ocean. This warning system was modeled after the one that exists for the Pacific Ocean.
Another earthquake.
On March 28, 2005, an undersea earthquake with a magnitude of 8.7 occurred in the Indian Ocean near Sumatra. The earthquake killed hundreds of people, mostly on the island of Nias off Sumatra’s west coast. Although the quake triggered tsunami warnings, it produced only small ocean waves. The epicenter of the March quake was just southeast of that of the December quake. Scientists believe the December quake probably created the pressures in Earth’s outer shell that led to the March quake.
See also Earthquake ; Tsunami .
