Asian Tsunami The Deadliest Wave
Enrique Vasquez
The 2004 Indian Ocean earthquake and tsunami, one of the most powerful natural disasters in recorded history, sent shockwaves through the region, impacting multiple countries and hundreds of thousands of lives. A massive undersea earthquake off the western coast of northern Sumatra, Indonesia, unleashed a series of colossal tsunamis that inundated coastal areas, catching communities off-guard and causing widespread destruction. The disaster not only brought immediate loss of life and destruction to infrastructure but also prompted a global reflection on the vulnerabilities of coastal regions and the importance of disaster preparedness and international collaboration.
The first giant waves from the Indian Ocean tsunami reached Banda Aceh, an Indonesian city of about 300,000 people, within 15 or 20 minutes of the earthquake. Few residents of the densely populated area realized that the earthquake they had felt could cause a tsunami, and there was little time to flee to higher ground.
Traveling as fast as 500 mph, the waves spread to other countries, including India, Myanmar, Sri Lanka, and Thailand. With no warning, coastal populations were caught by the pounding waves. Many families that made their living fishing lost everything; the tsunami wiped out whole communities.
In the aftermath of the 2004 Indian Ocean earthquake and tsunami, World Vision played a pivotal role in supporting the recovery efforts across five countries: India, Indonesia, Myanmar, Sri Lanka, and Thailand. Through our extensive relief operations, we raised more than $350 million and led one of our most substantial responses. Our impact included:
Sustainable restoration: Our teams implemented coastal restoration programs by planting 56,000 mangroves to serve as a natural barrier to rising ocean levels. We also helped in the restoration of a fishing harbor.
Our response includes providing food, access to clean water, hygiene items, and other essential supplies. We also promote disease prevention through hygiene training. Child protection initiatives address urgent cases such as family separation and violence. We also offer health, nutrition, and educational services.
It was 2004, the day after Christmas, and thousands of European and American tourists had flocked to the beaches of Thailand, Sri Lanka and Indonesia to escape the winter chill in a tropical paradise.
Thailand was next. With waves traveling 500 mph across the Indian Ocean, the tsunami hit the coastal provinces of Phang Nga and Phuket an hour and a half later. Despite the time-lapse, locals and tourists were caught completely unaware of the imminent destruction. Curious beachgoers even wandered out among the oddly receding waves, only to be chased down by a churning wall of water. The death toll in Thailand was nearly 5,400 including 2,000 foreign tourists.
An hour later, on the opposite side of the Indian Ocean, the waves struck the southeastern coast of India near the city of Chennai, pushing debris-choked water kilometers inland and killing more than 10,000 people, mostly women and children, since many of the men were out fishing. But some of the worst devastation was reserved for the island nation of Sri Lanka, where more than 30,000 people were swept away by the waves and hundreds of thousands left homeless.
Vasily Titov is a tsunami researcher and forecaster with the National Oceanic and Atmospheric Administration Center for Tsunami Research. He credits the unsparing destructiveness of the 2004 Indian Ocean tsunami on the raw power of the earthquake that spawned it. The quake originated in a so-called megathrust fault, where heavy oceanic plates subduct beneath lighter continental plates.
The 2004 quake ruptured a 900-mile stretch along the Indian and Australian plates 31 miles below the ocean floor. Rather than delivering one violent jolt, the quake lasted an unrelenting 10 minutes, releasing as much pent-up power as several thousand atomic bombs.
An earthquake and tsunami of the magnitude that struck in 2004 is so rare that catastrophic tsunamis are all but unknown in the long cultural histories of India and Sri Lanka, explains Jose Borrero, a tsunami researcher with the University of Southern California and director of eCoast, a marine consultancy based in New Zealand.
Both Borrero and Titov took part in U.S. Geological Survey expeditions in early 2005 to measure the full extent of the tsunami that struck Sumatra. It was during these expeditions that scientists confirmed maximum wave heights of more than 131 feet on the northwestern tip of the island. Borrero remembers coming upon a colossal freighter loaded with bags of cement that had been flipped on its back with its propeller in the air.
Dave Roos is a journalist and podcaster based in the U.S. and Mexico. He's the co-host of Biblical Time Machine, a history podcast, and a writer for the popular podcast Stuff You Should Know. Learn more at daveroos.com.
A massive tsunami with waves up to 30 m (100 ft) high, known as the Boxing Day Tsunami after the Boxing Day holiday, or as the Asian Tsunami,[10] devastated communities along the surrounding coasts of the Indian Ocean, killing an estimated 227,898 people in 14 countries in one of the deadliest natural disasters in recorded history. The direct results caused major disruptions to living conditions and commerce in coastal provinces of surrounded countries, including Aceh (Indonesia), Sri Lanka, Tamil Nadu (India) and Khao Lak (Thailand). Banda Aceh reported the largest number of deaths. It is the deadliest natural disaster of the 21st century,[11] and the worst tsunami disaster in history.[12] It is also the worst natural disaster in the history of Indonesia, Sri Lanka and Thailand.[13]
It was the most powerful earthquake ever recorded in Asia, the most powerful earthquake in the 21st century, and at least the third most powerful earthquake ever recorded in the world since modern seismography began in 1900.[14][a] It had the longest fault rupture ever observed, between 1,200 km to 1,300 km (720 mi to 780 mi), and had the longest duration of faulting ever observed, at least ten minutes.[18] It caused the planet to vibrate as much as 10 mm (0.4 in),[19] and also remotely triggered earthquakes as far away as Alaska.[20] Its epicentre was between Simeulue and mainland Sumatra.[21] The plight of the affected people and countries prompted a worldwide humanitarian response, with donations totalling more than US$14 billion[22] (equivalent to US$23 billion in 2023 currency).
The hypocentre of the main earthquake was approximately 160 km (100 mi) off the western coast of northern Sumatra, in the Indian Ocean just north of Simeulue island at a depth of 30 km (19 mi) below mean sea level (initially reported as 10 km or 6.2 mi). The northern section of the Sunda megathrust ruptured over a length of 1,300 km (810 mi).[21] The earthquake (followed by the tsunami) was felt in Bangladesh, India, Malaysia, Myanmar, Thailand, Sri Lanka and the Maldives.[31] Splay faults, or secondary "pop up faults", caused long, narrow parts of the seafloor to pop up in seconds. This quickly elevated the height and increased the speed of waves, destroying the nearby Indonesian town of Lhoknga.[32]
Indonesia lies between the Pacific Ring of Fire along the north-eastern islands adjacent to New Guinea, and the Alpide belt that runs along the south and west from Sumatra, Java, Bali, Flores to Timor. The 2002 Sumatra earthquake is believed to have been a foreshock, preceding the main event by over two years.[33]
Great earthquakes, such as the 2004 Indian Ocean earthquake, are associated with megathrust events in subduction zones. Their seismic moments can account for a significant fraction of the global seismic moment across century-scale periods. Of all the moment released by earthquakes in the 100 years from 1906 through 2005, roughly one eighth was due to the 2004 Indian Ocean earthquake.[34] This quake, together with the Great Alaskan earthquake (1964) and the Great Chilean earthquake (1960), account for almost half of the total moment.[34][35]
Since 1900, the only earthquakes recorded with a greater magnitude were the 1960 Valdivia earthquake (magnitude 9.5) and the 1964 Alaska earthquake in Prince William Sound (magnitude 9.2). The only other recorded earthquakes of magnitude 9.0 or greater were off Kamchatka, Russia, on 5 November 1952 (magnitude 9.0) and Tōhoku, Japan (magnitude 9.1) in March 2011. Each of these megathrust earthquakes also spawned tsunamis in the Pacific Ocean. In comparison to the 2004 Indian Ocean earthquake, the death toll from these earthquakes and tsunamis was significantly lower, primarily because of the lower population density along the coasts near affected areas.[8]
Comparisons with earlier earthquakes are difficult, as earthquake strength was not measured systematically until the 1930s.[36] However, historical earthquake strength can sometimes be estimated by examining historical descriptions of the damage caused, and the geological records of the areas where they occurred.[37] Some examples of significant historical megathrust earthquakes are the 1868 Arica earthquake in Peru and the 1700 Cascadia earthquake in western North America.
The Indian Plate is part of the Indo-Australian Plate, which underlies the Indian Ocean and Bay of Bengal, and is moving north-east at an average of 60 mm/a (0.075 in/Ms). The India Plate meets the Burma Plate (which is considered a portion of the great Eurasian Plate) at the Sunda Trench. At this point, the India Plate subducts beneath the Burma Plate, which carries the Nicobar Islands, the Andaman Islands, and northern Sumatra. The India Plate sinks deeper and deeper beneath the Burma Plate until the increasing temperature and pressure drive volatiles out of the subducting plate. These volatiles rise into the overlying plate, causing partial melting and the formation of magma. The rising magma intrudes into the crust above and exits the Earth's crust through volcanoes in the form of a volcanic arc. The volcanic activity that results as the Indo-Australian Plate subducts the Eurasian Plate has created the Sunda Arc.
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