The 2004 Indian Ocean earthquake was an undersea mega thrust earthquake that occurred at 00:58:53 UTC on Sunday, December 26, 2004, with an epicentre off the west coast of Sumatra, Indonesia. The quake itself is understood by the scientific neighborhood because the Sumatra-Andaman earthquake.  The ensuing tsunami is given numerous names, together with the 2004 Indian Ocean tsunami, Asian Tsunami, Indonesian Tsunami.
The earthquake was brought on by subduction and triggered a sequence of devastating tsunamis alongside the coasts of most landmasses bordering the Indian Ocean, killing over 230,000 folks in fourteen international locations, and inundating coastal communities with waves as much as 30 meters (100 toes) excessive.
 It was one of many deadliest pure disasters in recorded historical past. Indonesia was the toughest hit, adopted by Sri Lanka, India, and Thailand. With a magnitude of between 9. 1 and 9. three, it's the third largest earthquake ever recorded on a seismograph.
This earthquake had the longest period of faulting ever noticed, between eight. nd 10 minutes. It brought on the complete planet to vibrate as a lot as 1 cm (zero. four inches) and triggered different earthquakes as far-off as Alaska.
 Its hypocenter was between Simeulue and mainland Indonesia.  The hypocentre of the primary earthquake was roughly 160 km (100 mi), within the Indian Ocean simply north of Simeulue island, off the western coast of northern Sumatra, at a depth of 30 km (19 mi) under imply sea degree (initially reported as 10 km).
The northern part of the Sunda megathrust, which had been assumed dormant, ruptured; the rupture having a size of 1300 km. ] The dimensions of the rupture brought on plate shifting of as much as 20 m, inflicting the earthquake (adopted by the tsunami) to be felt concurrently as far-off as Bangladesh, India, Malaysia, Myanmar, Thailand, Singapore and the Maldives. Seismographic and acoustic knowledge point out that the primary part concerned a rupture about 400 km (250 mi) lengthy and 100 km (60 mi) vast, positioned 30 km (19 mi) beneath the ocean mattress—the most important rupture ever recognized to have been brought on by an earthquake.
The rupture proceeded at a pace of about 2. eight km/s (1. i/s) or 10,000 km/h (6,300 mph), starting off the coast of Aceh and continuing north-westerly over a interval of about 100 seconds. The sudden vertical rise of the seabed by a number of metres through the earthquake displaced huge volumes of water, leading to a tsunami that struck the coasts of the Indian Ocean. A tsunami which causes injury far-off from its supply is typically known as a teletsunami and is more likely to be produced by vertical movement of the seabed than by horizontal movement. [ The tsunami, like all others, behaved very in a different way in deep water than in shallow water.
In deep ocean water, tsunami waves type solely a small hump, barely noticeable and innocent, which usually travels at a really excessive pace of 500 to 1,000 km/h (310 to 620 mph); in shallow water close to coastlines, a tsunami slows right down to solely tens of kilometres an hour, however in doing so varieties giant damaging waves. Scientists investigating the injury in Aceh discovered proof that the wave reached a peak of 24 m (79 ft) when coming ashore alongside giant stretches of the shoreline, rising to 30 m (98 ft) in some areas when travelling inland. ]
Radar satellites recorded the heights of tsunami waves in deep water: at two hours after the earthquake, the utmost peak was 60 centimetres (2. zero ft). These are the primary such observations ever made. Sadly these observations couldn't be used to supply a warning, for the reason that satellites weren't constructed for that objective and the info took hours to investigate.  Coasts which have a landmass between them and the tsunami’s location of origin are often protected; nonetheless, tsunami waves can typically diffract round such landmasses.
Thus, the Indian state of Kerala was hit by the tsunami regardless of being on the western coast of India, and the western coast of Sri Lanka additionally suffered substantial impacts. Additionally distance alone was no assure of security; Somalia was hit more durable than Bangladesh regardless of being a lot farther away.
Regardless of a lag of as much as a number of hours between the earthquake and the influence of the tsunami, almost all the victims had been taken utterly unexpectedly. There have been no tsunami warning techniques within the Indian Ocean to detect tsunamis or to warn the overall populace residing across the ocean.
Tsunami detection isn't straightforward as a result of whereas a tsunami is in deep water it has little peak and a community of sensors is required to detect it. Organising the communications infrastructure to subject well timed warnings is a good greater drawback, partiIn the aftermath of the catastrophe, there's now an consciousness of the necessity for a tsunami warning system for the Indian Ocean. The United Nations began engaged on an Indian Ocean Tsunami Warning System and by 2005 had the preliminary steps in place. Some have even proposed making a unified international tsunami warning system, to incorporate the Atlantic Ocean and Caribbean.
Within the aftermath of the catastrophe, there's now an consciousness of the necessity for a tsunami warning system for the Indian Ocean. The United Nations began engaged on an Indian Ocean Tsunami Warning System and by 2005 had the preliminary steps in place. Some have even proposed making a unified international tsunami warning system, to incorporate the Atlantic Ocean and Caribbean. The primary warning signal of a doable tsunami is the earthquake itself. Nevertheless, tsunami can strike hundreds of kilometres away the place the earthquake is just felt weakly or by no means.
Additionally, within the minutes previous a tsunami strike, the ocean typically recedes briefly from the coast. Across the Indian Ocean, this uncommon sight reportedly induced folks, particularly youngsters, to go to the coast to research and gather stranded fish on as a lot as 2. 5 km (1. 6 mi) of uncovered seashore, with deadly outcomes.  Nevertheless, not all tsunami causes this “disappearing sea” impact. In some instances, there aren't any warning indicators in any respect: the ocean will all of a sudden swell with out retreating, shocking many individuals and giving them little time to flee.
The tsunami brought on severe injury and deaths so far as the east coast of Africa, with the furthest recorded loss of life because of the tsunami occurring at Rooi Els in South Africa, eight,000 km (four,971 mi) away from the epicentre. In complete, eight folks in South Africa died because of abnormally excessive sea ranges and waves. Distruction Tsunami causes destruction primarily because of the ultrahigh impacts on buildings and different property. The fundamental elements of destruction embrace, wave influence, erosion , and inundation. The drag utilized by tsunami waves on buildings can transfer them or overturn them.
The presence of excessive salt focus in tsunami waves causes corrosion of metallic our bodies, which decreases their life in the end resulting in failure. As tsunami causes giant scale structural destruction, the floating particles so fashioned poses severe risk to different buildings, or floating vessels. Apart from the first destruction, secondary destruction could embrace hearth hazards, and water air pollution. Fireplace hazards could also be brought on by severed electrical energy transmission traces, whereas broken oil tankers could contribute a severe risk to water high quality. Rescue The tsunami introduced in regards to the devastation of transport and communication infrastructure.
Roads had been destroyed, blocking entry by way of land to some affected areas. Thus, aerial and sea army transports had been required to achieve some rural areas. Helicopters are particularly efficient within the search and rescue operations. They don't require touchdown runways, they usually present a superb view for rescuers. Thus, rescuers are in a position to spot injured survivors, and evacuate them to security. The pressure of the tsunami has altered the panorama of coastal areas, rendering most standard topological maps ineffective. Due to this fact, ships with radar capabilities play supporting roles by coordinating the operations, and finishing up surveillance work.