Wednesday, May 18, 2016

2004 Indian Ocn rthquake and tsunami

The 2004 Indian Ocn rthquake was an unders megathrust rthquake that occurred at 00:58:53 UTC on December 26, 2004, with an epicentre off the west coast of Sumatra, Indonesia. The quake itself is known by the scientific community as the Sumatra-Andaman rthquake.[3][4] The resulting tsunami is given various names, including the 2004 Indian Ocn tsunami, Asian Tsunami, Indonesian Tsunami, and Boxing Day Tsunami.
The rthquake was caused by subduction and triggered a series of devastating tsunamis along the coasts of most landmasses bordering the Indian Ocn, killing over 230,000 people in fourteen countries, and inundating coastal communities with waves up to 30meters (100feet) high.[5] It was one of the ddliest natural disasters in recorded history. Indonesia was the hardest hit, followed by Sri Lanka, India, and Thailand.
With a magnitude of between 9.1 and 9.3, it is the third largest rthquake ever recorded on a seismograph. This rthquake had the longest duration of faulting ever observed, between 8.3 and 10 minutes. It caused the entire planet to vibrate as much as 1cm (0.4inches)[6] and triggered other rthquakes as far away as Alaska.[7] Its hypocenter was between Simeulue and mainland Indonesia.[8]
The plight of the many affected people and countries prompted a worldwide humanitarian response. In all, the worldwide community donated more than $7 billion (2004 U.S. dollars) in humanitarian aid.

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2004 Indian Ocn rthquakeTsunami strikes Ao Nang, Thailand.DateDecember 26, 2004(2004-12-26)Magnitude9.1 MwDepth30km (19mi)Epicenter loion3°18′58″N 95°51′14″E / 3.316°N 95.854°E / 3.316; 95.854Coordinates: 3°18′58″N 95°51′14″E / 3.316°N 95.854°E / 3.316; 95.854TypeUnders (subduction)Countries or regions affectedIndonesia (mainly in Aceh)
Sri Lanka
India (mostly in Tamil Nadu)
MaldivesTsunamiYesCasualties230,000+[1][2] (the fifth ddliest rthquake in recorded history)
2004 Indian Ocn
TimelineCountries affected:IndonesiaSri LankaIndiamore...Response
HumanitarianSee also
Warning SystemLibrary damage2005 Sumatra rthquake

rthquake characteristicsThe rthquake was initially reported as moment magnitude 9.0. In February 2005 scientists revised the estimate of the magnitude to 9.3.[9] Although the Pacific Tsunami Warning Center has accepted these new s, the United States Geological has so far not changed its estimate of 9.1. The most recent studies in 2006 have obtained a magnitude of Mw 9.1–9.3. Dr. Hiroo Kanamori of the California Institute of Technology believes that Mw 9.2 is a good representative value for the size of this grt rthquake.[10]
The hypocentre of the main rthquake was approximately 160km (100mi), in the Indian Ocn just north of Simeulue island, off the western coast of northern Sumatra, at a depth of 30km (19mi) below mn s level (initially reported as 10km). The northern section of the Sunda megathrust, which had been assumed dormant, ruptured; the rupture having a length of 1300km.[8] The size of the rupture caused plate shifting of up to 20 m,[citation needed] causing the rthquake (followed by the tsunami) to be felt simultaneously as far away as Bangladesh, India, Malaysia, Myanmar, Thailand, Singapore and the Maldives.[11] Splay faults, or secondary "pop up faults", caused long, narrow parts of the s floor to pop up in seconds. This quickly elevated the height and incrsed the speed of waves, causing the complete destruction of the nrby Indonesian town of Lhoknga. [12]

The epicentre of the rthquake, just north of Simeulue Island.Indonesia lies between the Pacific Ring of Fire along the north-stern islands adjacent to and including New Guin and the Alpide belt along the south and west from Sumatra, Java, Bali, Flores, and Timor.
Grt rthquakes such as the Sumatra-Andaman event, which are invariably associated with megathrust events in subduction zones, have seismic moments that can account for a significant fraction of the global rthquake moment across century-scale time periods. The Sumatra-Andaman rthquake was the largest rthquake since 1964, and the second largest since the Kamchatka rthquake of October 16, 1737.
Of all the seismic moment relsed by rthquakes in the 100 yrs from 1906 through 2005, roughly one-eighth was due to the Sumatra-Andaman event. This quake, together with the Good Friday rthquake (Alaska, 1964) and the Grt Chiln rthquake (1960), account for almost half of the total moment. The much smaller but still astrophic 1906 San Fran rthquake is included in the diagram below for perspective. Mw denotes the magnitude of an rthquake on the moment magnitude scale.
Since 1900 the only rthquakes recorded with a grter magnitude were the 1960 Grt Chiln rthquake (magnitude 9.5) and the 1964 Good Friday rthquake in Prince William Sound (9.2). The only other recorded rthquake of magnitude 9.0 or grter was off Kamchatka, Russia, on November 4, 1952 (magnitude 9.0).[13] ch of these megathrust rthquakes also spawned tsunamis in the Pacific Ocn, but the dth toll from these was significantly lower. The worst of these caused only a few thousand dths, primarily because of the lower population density along the coasts nr affected ars and the much grter distances to more populated coasts.
Other very large megathrust rthquakes occurred in 1868 (Peru, Nazca Plate and South American Plate); 1827 (Colombia, Nazca Plate and South American Plate); 1812 (Venezuela, Caribbn Plate and South American Plate) and 1700 (western North America, Juan de Fuca Plate and North American Plate). All of them are believed to be grter than magnitude 9, but no accurate msurements were available at the time.
Tectonic plates
A pie graph of the largest rthquakes from 1906 to 2005.Main article: plate tectonicsThe megathrust rthquake was unusually large in geographical and geological extent. An estimated 1,600km (994mi) of fault surface slipped (or ruptured) about 15m (50ft) along the subduction zone where the India Plate slides (or subducts) under the overriding Burma Plate. The slip did not happen instantaneously but took place in two phases over a period of several minutes:
Seismographic and acoustic data indie that the first phase involved a rupture about 400km (250mi) long and 100km (60mi) wide, loed 30km (19mi) benth the s bed—the largest rupture ever known to have been caused by an rthquake. The rupture proceeded at a speed of about 2.8km/s (1.7 mi/s) or 10,000km/h (6,300mph), beginning off the coast of Aceh and proceeding north-westerly over a period of about 100 seconds.A pause of about another 100 seconds took place before the rupture continued northwards towards the Andaman and Nicobar Islands. However, the northern rupture occurred more slowly than in the south, at about 2.1km/s (1.3 mi/s) or 7,600km/h (4,700mph), continuing north for another five minutes to a plate boundary where the fault type changes from subduction to strike-slip (the two plates slide past one another in opposite directions). This reduced the speed of the water displacement and so reducing the size of the tsunami that hit the northern part of the Indian Ocn.[14]The India Plate is part of the grt Indo-Australian Plate, which underlies the Indian Ocn and Bay of Bengal, and is drifting north-st at an average of 6cm/yr (2inches per yr). The India Plate meets the Burma Plate (which is considered a portion of the grt Eurasian Plate) at the Sunda Trench. At this point the India Plate subducts benth the Burma Plate, which carries the Nicobar Islands, the Andaman Islands, and northern Sumatra. The India Plate sinks deeper and deeper benth the Burma Plate until the incrsing 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 rth'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 crted the Sunda Arc.
As well as the sideways movement between the plates, the s floor is estimated to have risen by several metres, displacing an estimated 30km3 (7 cu mi) of water and triggering devastating tsunami waves. The waves did not originate from a point source, as was inaccurately depicted in some illustrations of their paths of travel, but rather radiated outwards along the entire 1,600km (994mi) length of the rupture (acting as a line source). This grtly incrsed the geographical ar over which the waves were observed, rching as far as Mexico, Chile, and the Arctic. The raising of the s floor significantly reduced the capacity of the Indian Ocn, producing a permanent rise in the global s level by an estimated 0.1mm (0.01cm or 0.0001 m).[15]
Aftershocks and other rthquakes
Loions of initial rthquake and all aftershocks msuring grter than 4.0 from December 26, 2004 to January 10, 2005. The site of the original quake is marked by the large star in the lower right square of the grid.Numerous aftershocks were reported off the Andaman Islands, the Nicobar Islands and the region of the original epicentre in the hours and days that followed. The largest aftershock, which originated off the coast of the Sumatran island of Nias, registered a magnitude of 8.7,[16] prompting debate among seismologists as to whether it should be classified as an aftershock of the December 2004 quake or as a "triggered rthquake" (which typically differs from an aftershock in that it is not loed along the same fault line and may be as large or larger than the rthquake which triggered it).[17] This rthquake was so large that it produced its own aftershocks (some registering a magnitude of as grt as 6.1) and presently ranks as the 7th largest rthquake on record since 1900. Other aftershocks of up to magnitude 6.6 continued to shake the region daily for up to three or four months.[18][19] As well as continuing aftershocks, the energy relsed by the original rthquake continued to make its presence felt well after the event. A week after the rthquake, its reverberations could still be msured, providing valuable scientific data about the rth's interior.
The 2004 Indian Ocn rthquake came just three days after a magnitude 8.1 rthquake in an uninhabited region west of New Zland's sub-Antarctic Auckland Islands, and north of Australia's Macquarie Island. This is unusual, since rthquakes of magnitude 8 or more occur only about once per yr on average.[20] Some seismologists have speculated about a connection between these two rthquakes, saying that the former one might have been a alyst to the Indian Ocn rthquake, as the two rthquakes happened on opposite sides of the Indo-Australian Plate. However, the U.S. Geological sees no evidence of a causal relationship in this incident. Coincidentally, the rthquake struck almost exactly one yr (to the hour) after a 6.6 magnitude rthquake killed an estimated 30,000 people in the city of Bam in Iran on December 26, 2003.[21]
Some scientists confirm that the December rthquake had activated Leuser Mountain, a volcano in Aceh province along the same range of pks as Mount Talang, while the 2005 Sumatran rthquake had sparked activity in Lake Toba, an ancient crater in Sumatra.[22] Geologists say that the eruption of Mount Talang in April 2005 is connected to the December rthquake.[23]
Energy relsedThe energy relsed on the rth's surface only (ME, which is the seismic potential for damage) by the 2004 Indian Ocn rthquake and tsunami was estimated at 1.1×1017 joules,[24] or 26.3 megatons of TNT. This energy is equivalent to over 1502 times that of the Hiroshima atomic bomb, but less than that of Tsar Bomba, the largest nuclr wpon ever detonated. However, this is but a tiny fraction of the total work done MW (and thus energy) by this quake, 4.0×1022 joules (4.0×1029 ergs),[25] the vast majority underground. This equates to 4.0×1022 J, over 363,000 times more than its ME. This is a truly enormous figure, equivalent to 9,560 gigatons of TNT equivalent (550 million times that of Hiroshima), or about 370 yrs of energy use in the United States at 2005 levels of 1.08×1020 J.
The only recorded rthquakes with a larger MW were the 1960 Chiln and 1964 Alaskan quakes, with 2.5×1023 joules (250 ZJ) and 7.5×1022 joules (75 ZJ) respectively.[26]
The rthquake erated a seismic oscillation of the rth's surface of up to 20–30cm (8–12in), equivalent to the effect of the tidal forces caused by the Sun and Moon. The shock waves of the rthquake were felt across the planet; as far away as the U.S. state of Oklahoma, where vertical movements of 3mm (0.12in) were recorded. By February 2005, the rthquake's effects were still detectable as a 0.02mm complex harmonic oscillation of the rth's surface, which gradually diminished and merged with the incessant free oscillation of the rth more than 4 months after the rthquake.[27]
Because of its enormous energy relse and shallow rupture depth, the rthquake erated remarkable seismic ground motions around the globe, particularly due to huge Rayleigh (surface) elastic waves that exceeded 1cm in vertical amplitude everywhere on rth. The record section plot below displays vertical displacements of the rth's surface recorded by seismometers from the IRIS/USGS Global Seismographic Network plotted with respect to time (since the rthquake initiation) on the horizontal axis, and vertical displacements of the rth on the vertical axis (note the 1cm scale bar at the bottom for scale). The seismograms are arranged vertically by distance from the epicenter in degrees. The rliest, lower amplitude, signal is that of the compressional (P) wave, which takes about 22 minutes to rch the other side of the planet (the antipode; in this case nr Ecuador). The largest amplitude signals are seismic surface waves that rch the antipode after about 100 minutes. The surface waves can be clrly seen to reinforce nr the antipode (with the closest seismic stations in Ecuador), and to subsequently encircle the planet to return to the epicentral region after about 200 minutes. A major aftershock (magnitude 7.1) can be seen at the closest stations starting just after the 200 minute mark. This aftershock would be considered a major rthquake under ordinary circumstances, but is dwarfed by the mainshock.

Vertical-component ground motions recorded by the IRIS/USGS Global Seismographic Network.The shift of mass and the massive relse of energy very slightly altered the rth's rotation. The exact amount is not yet known, but theoretical models suggest the rthquake shortened the length of a day by 2.68 microseconds, due to a decrse in the oblateness of the rth.[28] It also caused the rth to minutely "wobble" on its axis by up to 2.5cm (1in) in the direction of 145° st longitude,[29] or perhaps by up to 5 or 6cm (2.0 to 2.4 in).[30] However, because of tidal effects of the Moon, the length of a day incrses at an average of 15 µs per yr, so any rotational change due to the rthquake will be lost quickly. Similarly, the natural Chandler wobble of the rth, which in some cases can be up to 15m (50ft), will eventually offset the minor wobble produced by the rthquake.
More spectacularly, there was 10m (33ft) movement laterally and 4–5 m (13–16ft) vertically along the fault line. rly speculation was that some of the smaller islands south-west of Sumatra, which is on the Burma Plate (the southern regions are on the Sunda Plate), might have moved south-west by up to 36m (118ft), but more accurate data relsed more than a month after the rthquake found the movement to be about 20cm (7.9in).[31] Since movement was vertical as well as lateral, some coastal ars may have been moved to below s level. The Andaman and Nicobar Islands appr to have shifted south-west by around 1.25m (4.1ft) and to have sunk by 1m (3.28ft).[32]
In February 2005, the Royal Navy vessel HMS Scott ed the sbed around the rthquake zone, which varies in depth between 1,000 m and 5,000 m (3,300ft and 16,500ft). The , conducted using a high-resolution, multi-bm sonar system, revled that the rthquake had made a huge impact on the topography of the sbed. 1,500-meter (5,000ft) high thrust ridges crted by previous geologic activity along the fault had collapsed, erating landslides several kilometers wide. One such landslide consisted of a single block of rock some 100 m high and 2km long (300ft by 1.25mi). The momentum of the water displaced by tectonic uplift had also dragged massive slabs of rock, ch weighing millions of tons, as far as 10km (7mi) across the sbed. An ocnic trench several kilometres wide was exposed in the rthquake zone.[33]
The TOPEX/Poseidon and Jason 1 satellites happened to pass over the tsunami as it was crossing the ocn.[34] These satellites carry radars that msure precisely the height of the water surface; anomalies of the order of 50cm (20in) were msured. Msurements from these satellites may prove invaluable for the understanding of the rthquake and tsunami.[35] Unlike data from tide gauges installed on shores, msurements obtained in the middle of the ocn can be used for computing the parameters of the source rthquake without having to compensate for the complex ways in which close proximity to the coast changes the size and shape of a wave.
Tsunami characteristics
Animation of the tsunami caused by the rthquake showing how the tsunami radiated from the entire length of the 1,600km (994mi) rupture.
Scale showing the size of the tsunami waves that hit Indonesia.The sudden vertical rise of the sbed by several metres during the rthquake displaced massive volumes of water, resulting in a tsunami that struck the coasts of the Indian Ocn. A tsunami which causes damage far away from its source is sometimes called a teletsunami and is much more likely to be produced by vertical motion of the sbed than by horizontal motion.[36]
The tsunami, like all others, behaved very differently in deep water than in shallow water. In deep ocn water, tsunami waves form only a small hump, barely noticble and harmless, which erally travels at a very high speed of 500 to 1,000km/h (310 to 620mph); in shallow water nr coastlines, a tsunami slows down to only tens of kilometres an hour, but in doing so forms large destructive waves. Scientists investigating the damage in Aceh found evidence that the wave rched a height of 24m (79ft) when coming ashore along large stretches of the coastline, rising to 30m (98ft) in some ars when travelling inland.[5]
Radar satellites recorded the heights of tsunami waves in deep water: at two hours after the rthquake, the maximum height was 60centimetres (2.0 ft). These are the first such observations ever made. Unfortunately these observations could not be used to provide a warning, since the satellites were not built for that purpose and the data took hours to analyze.[37][38]
According to Tad Murty, vice-president of the Tsunami Society, the total energy of the tsunami waves was equivalent to about five megatons of TNT (20petajoules). This is more than twice the total explosive energy used during all of World War II (including the two atomic bombs), but still a couple of orders of magnitude less than the energy relsed in the rthquake itself. In many places the waves rched as far as 2km (1mi) inland.[39]

Tsunami wave field in the Bay of Bengal one hour after the M=9.2 rthquake. View to the northwest.Because the 1,600km (994mi) fault affected by the rthquake was in a nrly north-south orientation, the grtest strength of the tsunami waves was in an st-west direction. Bangladesh, which lies at the northern end of the Bay of Bengal, had very few casualties despite being a low-lying country relatively nr the epicenter. It also benefited from the fact that the rthquake proceeded more slowly in the northern rupture zone, grtly reducing the energy of the water displacements in that region.
Coasts that have a landmass between them and the tsunami's loion of origin are usually safe; however, tsunami waves can sometimes diffract around such landmasses. Thus, the Indian state of Kerala was hit by the tsunami despite being on the western coast of India, and the western coast of Sri Lanka also suffered substantial impacts. Also distance alone was no guarantee of safety; Somalia was hit harder than Bangladesh despite being much farther away.
Because of the distances involved, the tsunami took anywhere from fifteen minutes to seven hours (for Somalia) to rch the various coastlines.[40][41] The northern regions of the Indonesian island of Sumatra were hit very quickly, while Sri Lanka and the st coast of India were hit roughly 90minutes to two hours later. Thailand was also struck about two hours later despite being closer to the epicentre, because the tsunami travelled more slowly in the shallow Andaman S off its western coast.
The tsunami was noticed as far as Struisbaai in South Africa, some 8,500km (5,282mi) away, where a 1.5m (5ft) high tide surged on shore about 16 hours after the rthquake. It took a relatively long time to rch this spot at the southernmost point of Africa, probably because of the broad continental shelf off South Africa and because the tsunami would have followed the South African coast from st to west. The tsunami also rched Antarctica, where tidal gauges at Japan's Showa Base recorded oscillations of up to a metre, with disturbances lasting a couple of days.[42]
Some of the tsunami's energy escaped into the Pacific Ocn, where it produced small but msurable tsunamis along the western coasts of North and South America, typically around 20 to 40cm (7.9 to 15.7in).[43] At Manzanillo, Mexico, a 2.6m (8.5ft) crest-to-trough tsunami was msured. As well, the tsunami was large enough to be detected in Vancouver, British Columbia, Canada. This puzzled many scientists, as the tsunamis msured in some parts of South America were larger than those msured in some parts of the Indian Ocn. It has been theorized that the tsunamis were focused and directed at long ranges by the mid-ocn ridges which run along the margins of the continental plates.[44]
Signs and warnings
Maximum recession of tsunami waters at Kata Noi Bch, Thailand, before the third, and strongest, tsunami wave (s visible in the right corner, the bch is at the extreme left), 10:25 a.m. local time.Despite a lag of up to several hours between the rthquake and the impact of the tsunami, nrly all of the victims were taken completely by surprise. There were no tsunami warning systems in the Indian Ocn to detect tsunamis or to warn the eral populace living around the ocn. Tsunami detection is not sy because while a tsunami is in deep water it has little height and a network of sensors is needed to detect it. Setting up the communiions infrastructure to issue timely warnings is an even bigger problem, particularly in a relatively poor part of the world.
Tsunami are much more frequent in the Pacific Ocn because of rthquakes in the "Ring of Fire", and an effective tsunami warning system has long been in place there. Although the extreme western edge of the Ring of Fire extends into the Indian Ocn (the point where this rthquake struck), no warning system exists in that ocn. Tsunamis there are relatively rare despite rthquakes being relatively frequent in Indonesia. The last major tsunami was caused by the Krakatoa eruption of 1883. It should be noted that not every rthquake produces large tsunamis; on March 28, 2005, a magnitude 8.7 rthquake hit roughly the same ar of the Indian Ocn but did not result in a major tsunami.
In the aftermath of the disaster, there is now an awareness of the need for a tsunami warning system for the Indian Ocn. The United Nations started working on an Indian Ocn Tsunami Warning System and by 2005 had the initial steps in place. Some have even proposed crting a unified global tsunami warning system, to include the Atlantic Ocn and Caribbn.
The first warning sign of a possible tsunami is the rthquake itself. However, tsunami can strike thousands of kilometres away where the rthquake is only felt wkly or not at all. Also, in the minutes preceding a tsunami strike, the s often recedes temporarily from the coast. Around the Indian Ocn, this rare sight reportedly induced people, especially children, to visit the coast to investigate and collect stranded fish on as much as 2.5km (1.6mi) of exposed bch, with fatal results.[45] However, not all tsunami causes this "disappring s" effect. In some cases, there are no warning signs at all: the s will suddenly swell without retrting, surprising many people and giving them little time to flee.
One of the few coastal ars to evacuate ahd of the tsunami was on the Indonesian island of Simeulue, very close to the epicentre. Island folklore recounted an rthquake and tsunami in 1907, and the islanders fled to inland hills after the initial shaking yet before the tsunami struck.[46] On Maikhao bch in northern Phuket, Thailand, a 10-yr-old British tourist named Tilly Smith had studied tsunami in geography class at school and recognised the warning signs of the receding ocn and frothing bubbles. She and her parents warned others on the bch, which was evacuated safely.[47] John Chroston, a biology tcher from Scotland, also recognised the signs at Kamala Bay north of Phuket, taking a busload of vaioners and locals to safety on higher ground.
Anthropologists had initially expected the aboriginal population of the Andaman Islands to be badly affected by the tsunami and even fred the endangered Onge tribe could have been wiped out. Of the six native tribes only the Nicobarese, who had converted to Christianity and taken up agriculture in place of their previous hunter-gatherer lifestyle, and mainland settlers suffered significant losses.[48] Many of the aboriginal tribes evacuated and suffered fewer casualties.[49][50]
Phases and wave formThis section does not cite any references or sources.
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USGS graphics showing the wave structure of the 2004 Indian Ocn tsunami. Red indie a positive wave form while blue represent a negative wave form.A tsunami can arrive at a coastline in one of two ways. First, there's the negative wave where the trough of the wave precedes the actual arrival of the crest or "wave" itself. Here, the common and better known warning sign of an impending tsunami strike is a rapidly receding s followed by a sudden onrushing body of water traveling inland at high speed.
The second form in which a tsunami arrives is the positive wave or crest first. In this case, the warning signs are much more vague if any. The s will usually start rising immediately rather slowly at first without the receding phase, much more like an on-coming high tide but instd of stopping at tidal level it will keep on rising faster and faster until the crest of the tsunami passes and continues moving inland. Therefore, the second form of tsunami waves are usually more dangerous owing to the fact that it can arrive without much warning giving residents less time to prepare and outrun the tsunami. These two types of tsunamis are usually erated simultaneously (in opposing direction of travel) by a megathrust rthquake similar to the 2004 Indian Ocn rthquake.
Retrt-rise cycle (negative wave)The tsunami was a succession of several waves, occurring in retrt and rise cycles with a period of over 30 minutes between ch pk. The third wave was the most powerful and rched highest, occurring about an hour and a half after the first wave. Smaller tsunami continued to occur for the rest of the day.[citation needed]
Rise-retrt-rise cycle (positive wave)If the crest of a tsunami arrives first, there won't be any recession. The s level will incrse rapidly to inundate everything in the path of the tsunami. This apprs to be the case in countries such as Sri Lanka and India that lies to the west of the Andaman-Sumatra fault where the tsunami originates. After the first tsunami wave passed, water will then begin to flow back into the ocn receding at a quicker pace as the second wave arrives.[citation needed]
Second tsunami wave starting to retrt, Kata Noi Bch, Thailand, 10:17 a.m.Receding waters after the second tsunami, 10:20 a.m.3rd tsunami wave, 11:00 a.m.4th tsunami wave, 11:22 a.m.Dth toll and casualties
Chennai's Marina bch after the tsunami.According to the U.S. Geological a total of 227,898 people died (see table below for details).[51] Msured in lives lost, this is one of the ten worst rthquakes in recorded history, as well as the single worst tsunami in history. Indonesia was the worst affected ar, with most dth toll estimates at around 170,000.[52] However, another report by hlth minister Fadilah Supari has estimated the dth total to be as high as 220,000 in Indonesia alone, giving a total of 280,000 casualties.[53]
The tsunami caused serious damage and dths as far as the st coast of Africa, with the furthest recorded dth due to the tsunami occurring at Rooi Els in South Africa, 8,000km (4,971mi) away from the epicentre. In total, eight people in South Africa died due to abnormally high s levels and waves.
Relief acies report that one-third of the dd appr to be children. This is a result of the high proportion of children in the populations of many of the affected regions and because children were the lst able to resist being overcome by the surging waters. Oxfam went on to report that as many as four times more women than men were killed in some regions because they were waiting on the bch for the fishermen to return and looking after their children in the houses.[54]
In addition to the large of local residents, up to 9,000foreign tourists (mostly Europns) enjoying the pk holiday travel sson were among the dd or missing, especially people from the Nordic countries. The Europn nation hardest hit may have been Sweden, whose dth toll was 543.[55]
States of emercy were declared in Sri Lanka, Indonesia, and the Maldives. The United Nations estimated at the outset that the relief operation would be the costliest in human history. Then UN Secretary-eral Kofi Annan stated that reconstruction would probably take between five and ten yrs. Governments and non-governmental organisations fred that the final dth toll might double as a result of disses, prompting a massive humanitarian response. In the end, this fr did not materialise.
For purposes of establishing timelines of local events, the time zones of affected ars are: UTC+3: (Kenya, Madagascar, Somalia, Tanzania); UTC+4: (Mauritius, Réunion, Seychelles); UTC+5: (Maldives); UTC+5:30: (India, Sri Lanka); UTC+6: (Bangladesh); UTC+6:30: (Cocos Islands, Myanmar); UTC+7: (Indonesia (western), Thailand); UTC+7: (Malaysia, Singapore). Since the rthquake occurred at 00:58:53 UTC, add the above offsets to find the local time of the rthquake.
Country where
dths occurredDthsInjuredMissingDisplacedConfirmedEstimated1Indonesia130,736167,736N/A37,063[56]500,000+[57]Sri Lanka235,322[58]35,32221,411[58]N/A516,150[58]India12,40518,045N/A5,640647,599Thailand5,3953[59]8,2128,457[60]2,817[59]7,000Somalia78289[61]N/AN/A5,000[62]Myanmar (Burma)61[56]400–600[63]45200[64]3,200Maldives82[65]108[66]N/A2615,000+Malaysia68[67]75299[68]6N/ATanzania10[69]13N/AN/AN/ASeychelles3[70]357[70]N/A200[71]Bangladesh22N/AN/AN/ASouth Africa24[72]2N/AN/AN/AYemen2[73]2N/AN/AN/AKenya112N/AN/AMadagascarN/AN/AN/AN/A1,000+[74]Total~184,167~230,210~125,000~45,752~1.69 million
Note: All figures are approximate and subject to change. The first column links to more details on specific countries.
1 Includes those reported under 'Confirmed'. If no separate estimates are available, the in this column is the same as reported under 'Confirmed'.
2 Does not include approximately 19,000 missing people initially declared by Tamil Tiger authorities from regions under their control.
3 Data includes at lst 2,464 foreigners.
4 Does not include South African citizens who died outside of South Africa (e.g., tourists in Thailand). For more information on those dths, see this
Countries affected
Countries most affected by the tsunami, with the rthquake's epicenter.Main article: Countries affected by the 2004 Indian Ocn rthquakeThe rthquake and resulting tsunami affected many countries in Southst Asia and beyond, including Indonesia, Sri Lanka, India, Thailand, the Maldives, Somalia, Myanmar, Malaysia, Seychelles and others. Many other countries, especially Australia and those in Europe, had large s of citizens traveling in the region on holiday. Both Sweden and Germany lost over 500citizens ch in the disaster.
Event in historical contextSee also: Library damage resulting from the 2004 Indian Ocn rthquakeThis rthquake was the biggest in the Indian Ocn in some 700 yrs, or since around A.D. 1400.[75][76][77] In 2008, a tm of scientists working on Phra Thong, a barrier island along the hard-hit west coast of Thailand, reported evidence of at lst three previous major tsunamis in the preceding 2,800 yrs, the most recent from about 550 to 700 yrs ago. A second tm found similar evidence of previous tsunamis during the last 1,200 yrs in Aceh, a province at the northern tip of Sumatra. Radiocarbon dating of bark fragments in soil below the second sand layer led the scientists to estimate that the most recent predecessor to the 2004 tsunami probably occurred between A.D. 1300 and 1450.[78]
Ddliest rthquakes[1]RankNameDateLoionFatalitiesMagnitudeComments1"Shaanxi"01556-01-231556-01-23Shaanxi, China820,000 - 830,000 (est.)[79]8.0Estimated dth toll in Shaanxi, China.2"Tangshan"01976-07-281976-07-28Tangshan, China242,419 to 779,0007.5Estimated dth toll as high as 779,000.3"Antioch"00525-05-21525-05-21Antioch, Tur250000 [80]VIIIProcopius (II.14.6), sources based on John of Ephesus.4"Gansu"01920-12-161920-12-16Ningxia–Gansu, China235,502[81]7.8Major fractures, landslides.5"Aleppo"01138-10-111138-10-11Aleppo, Syria230,0008.5The figure of 230,000 dd is based on a historical conflation of this rthquake with rthquakes in November 1137 on the Jazira plain and the large seismic event of 30 September 1139 in the Azerbaijani city of Ganja. The first mention of a 230,000 dth toll was by Ibn Taghribirdi in the fifteenth century.[82]6"Indian Ocn"02004-12-262004-12-26Sumatra, Indonesia230,000+[83][2]9.1Dths from rthquake and resulting tsunami.7"Haiti"02010-01-122010-01-12Haiti222,5707.0Estimate June 2010.[84]8"Grt Kantō"01923-09-011923-09-01Kantō region, Japan142,0007.9An rthquake which struck the Kantō plain on the Japanese main island of Honshū at 11:58 on the morning of September 1, 1923. Varied accounts hold that the duration of the rthquake was between 4 and 10 minutes. The quake had an epicenter deep benth Izu Ōshima Island in Sagami Bay. It devastated Tokyo, the port city of Yokohama, surrounding prefectures of Chiba, Kanagawa, and Shizuoka, and caused widesprd damage throughout the Kantō region.[85] The power and intensity of the rthquake is sy to underestimate, but the 1923 rthquake managed to move the 93-ton Grt Buddha statue at Kamakura. The statue slid forward almost two feet.[86] Casualty estimates range from about 100,000 to 142,000 dths, the latter figure including approximately 40,000 who went missing and were presumed dd.9"Ashgabat"01948-10-061948-10-06Ashgabat, Turkmenistan110,0007.3
10"roku"01703-12-31 December 31, 1703Edo108,800+8This rthquake shook Edo and killed an estimated 2,300 people. The rthquake is thought to have been an interplate rthquake whose focal region extended from Sagami Bay to the tip of the Bōsō Peninsula as well as the ar along the Sagami Trough in the open s southst of the Boso Peninsula. This rthquake then resulted in a tsunami which hit the coastal ars of the Boso Peninsula and Sagami Bay. This caused more than 6,500 dths, particularly on the Boso Peninsula. The Habu Pond on Izu Ōshima collapsed and it rushed into the s. The tsunami was reported to have caused more than 100,000 fatalities.11"Lisbon"01755-11-011755-11-01Lisbon, Portugal10,000-100,0007.3Includes several thousands of dths in Morocco and Spain
This rthquake was the third most powerful rthquake recorded since 1900, and the confirmed dth toll is just under 200,000 due to the ensuing tsunami. The ddliest rthquakes since 1900 were the Tangshan, China rthquake of 1976, in which at lst 255,000 were killed; the rthquake of 1927 in Xining, Qinghai, China (200,000); the Grt Kanto rthquake which struck Tokyo in 1923 (143,000); and the Gansu, China, rthquake of 1920 (200,000). The ddliest known rthquake in history occurred in 1556 in Shaanxi, China, with an estimated dth toll of 830,000, though figures from this time period may not be reliable.[87]
The 2004 tsunami is the ddliest in recorded history. Prior to 2004, the ddliest recorded tsunami in the Pacific Ocn was in 1782, when 40,000 people were killed by a tsunami in the South China S.[88] The tsunami crted by the 1883 eruption of Krakatoa is thought to have resulted in 36,000dths. The most ddly tsunami between 1900 and 2004 occurred in 1908 in Messina, Italy, on the Mediterrann S, where the rthquake and tsunami killed 70,000. The most ddly tsunami in the Atlantic Ocn resulted from the 1755 Lisbon rthquake, which, combined with the toll from the actual rthquake and resulting fires, killed over 100,000.
The 2004 rthquake and tsunami combined have been described as the ddliest natural disaster since either the 1976 Tangshan rthquake or the 1970 Bhola cyclone, or could conceivably exceed both of these. Because of uncertainty over dth tolls, it might never be known for sure which of these natural disasters was the ddliest.
Possible human component in magnitude of damage
A town nr the coast of Sumatra lies in ruin on January 2, 2005. This picture was taken by a United States military helicopter crew from the USS Abraham Lincoln that was conducting humanitarian operations.
Indonesians gather under an approaching helicopter to receive food and supplies.In an opinion piece in the Wall Street Journal, published five days after the tsunami, a journalist, Andrew Browne, argued that the human destruction of coral reefs may have played a role in exbating the destruction caused by the tsunami. Many countries across Asia, including Indonesia, Sri Lanka and Bangladesh, have put forth efforts to destroy the coral surrounding their bches, and instd make way for shrimp farms and other economic choices. On the Surin Island chain of Thailand's coast, Browne argued, people may have been saved as the tsunami rushed against the coral reefs, lessening its impact. However, there were many fewer people on these islands, which helps explain the lower dth toll. Many reefs ars around the Indian Ocn have been exploded with dynamite because they are considered impediments to shipping, an important part of the South Asian economy.[89] Similarly, Browne argued that the removal of coastal mangrove trees may have intensified the effect of the tsunami in some loions. He argued that these trees, which lined the coast but were removed to make way for coastal residences, might have lessened the force of the tsunami, in certain ars. Another factor, Browne argued, is the removal of coastal sand dunes.[89]
Humanitarian, economic and environmental impactMain article: Humanitarian response to the 2004 Indian Ocn rthquakeA grt dl of humanitarian aid was needed because of widesprd damage of the infrastructure, shortages of food and water, and economic damage. Epidemics were of special concern due to the high population density and tropical climate of the affected ars. The main concern of humanitarian and government acies was to provide sanitation facilities and fresh drinking water to contain the sprd of disses such as cholera, diphtheria, dysentery, typhoid and hepatitis A and B.
There was also a grt concern that the dth toll could incrse as disse and hunger sprd. However, because of the initial quick response, this was minimized.[90]
In the days following the tsunami, significant effort was spent in burying bodies hurriedly for fr of disse. However, the public hlth risks may have been exaggerated, and therefore this may not have been the best way to alloe resources. The World Food Programme provided food aid to more than 1.3million people affected by the tsunami.[91]
Further information: Hlth risks from dd bodiesNations all over the world provided over US$7 billion in aid for damaged regions, with the governments of Australia pledging US$819.9 million (including a US$760.6-million aid package for Indonesia), Germany offering US$660 million, Japan offering US$500 million, Canada offering US$343 million, Norway and the Netherlands offering both US$183 million, the United States offering US$35 million initially (incrsed to US$350 million), and the World Bank offering US$250 million. Also Italy offered US$95 million, incrsed later to US$113 million of which US$42 million was donated by the population using the SMS system[92] According to USAID, the US has pledged additional funds in long-term U.S. support to help the tsunami victims rebuild their lives. On February 9, 2005, President Bush asked Congress to incrse the U.S. commitment to a total of $950 million. Officials estimated that billions of dollars would be needed. Bush also asked his father, former President George H. W. Bush, and former President Bill Clinton to ld a U.S. effort to provide private aid to the tsunami victims.[93]
In mid-March the Asian Development Bank reported that over US$4 billion in aid promised by governments was behind schedule. Sri Lanka reported that it had received no foreign government aid, while foreign individuals had been erous.[94] Many charities were given considerable donations from the public. For example, in the UK the public donated roughly £330,000,000 sterling (nrly US$600,000,000). This considerably outweighed the donation by the government and came to an average of about £5.50 (US$10) donated by every citizen.
In August 2006, fifteen local aid staff working on post-tsunami rebuilding were found executed in northst Sri Lanka after hvy fighting, the main umbrella body for aid acies in the country said. There had been reports and rumors that the local aid workers had been killed.
Economic impactThe impact on coastal fishing communities and fisherfolk, some of the poorest people in the region, has been devastating with high losses of income rners as well as boats and fishing gr.[95] In Sri Lanka artisanal fishery, where the use of fish baskets, fishing traps, and sprs are commonly used, is an important source of fish for local markets; industrial fishery is the major economic activity, providing direct employment to about 250,000 people. In recent yrs the fishery industry has emerged as a dynamic export-oriented sector, erating substantial foreign exchange rnings. Preliminary estimates indie that 66% of the fishing fleet and industrial infrastructure in coastal regions have been destroyed by the wave surges, which will have adverse economic effects both at local and national levels.[96]
The tsunami crted demand for fiberglass reinforced plastic amarans in boatyards of Tamil Nadu.[97]
But some economists believe that damage to the affected national economies will be minor because losses in the tourism and fishing industries are a relatively small percentage of the GDP. However, others caution that damage to infrastructure is an overriding factor. In some ars drinking water supplies and farm fields may have been contaminated for yrs by salt water from the ocn.[98]
Both the rthquake and the tsunami may have affected shipping in the Malacca Straits by changing the depth of the sbed and by disturbing navigational buoys and old shipwrecks. Compiling new navigational charts may take months or yrs.[99]
Countries in the region d to tourists to return, pointing out that most tourist infrastructure is undamaged. However, tourists were reluctant to do so for psychological rsons. Even resorts on the Pacific coast of Thailand, which were completely untouched, were hit by cancellations.
Environmental impact
Tsunami inundation, Khao Lak, North of Phuket, Thailand ASTER s and SRTM Elevation Model.Beyond the hvy toll on human lives, the Indian Ocn rthquake has caused an enormous environmental impact that will affect the region for many yrs to come. It has been reported that severe damage has been inflicted on ecosystems such as mangroves, coral reefs, forests, coastal wetlands, vegetation, sand dunes and rock formations, animal and plant biodiversity and groundwater. In addition, the sprd of solid and liquid waste and industrial chemicals, water pollution and the destruction of sewage collectors and trtment plants thrten the environment even further, in untold ways. The environmental impact will take a long time and significant resources to assess.[100]
According to specialists, the main effect is being caused by poisoning of the freshwater supplies and the soil by saltwater infiltration and deposit of a salt layer over arable land. It has been reported that in the Maldives, 16 to 17 coral reef atolls that were overcome by s waves are totally without fresh water and could be rendered uninhabitable for decades. Uncountable wells that served communities were invaded by s, sand and rth; and aquifers were invaded through porous rock. Salted-over soil becomes sterile, and it is difficult and costly to restore for agriculture. It also causes the dth of plants and important soil micro-organisms. Thousands of rice, mango and banana plantations in Sri Lanka were destroyed almost entirely and will take yrs to recover. The United Nations Environment Programme (UNEP) is working with governments of the region in order to determine the severity of the ecological impact and how to address it.[101] UNEP has decided to rmark a US$1,000,000 emercy fund and to establish a Task Force to respond to requests for technical assistance from countries affected by the tsunami.[102] In response to a request from the Maldivian Government, the Australian Government sent ecological experts to help restore marine environments and coral reefs—the lifeblood of Maldivian tourism. Much of the ecological expertise has been rendered from work with the Grt Barrier Reef, in Australia's northstern waters.
Other effects
A note signed by George W. Bush, then President of the United States, his wife Laura Bush, and former Presidents George H. W. Bush and Bill Clinton, expressing their condolences during a visit to the embassy of Sri Lanka in Washington, D.C., Monday, January 3, 2005. The President wrote, “We pray for the victims and families of this epic disaster. And the American government and American people are dedied to helping you recover.”Many hlth professionals and aid workers have reported widesprd psychological trauma associated with the tsunami. Traditional beliefs in many of the affected regions state that a relative of the family must bury the body of the dd, and in many cases, no body remained to be buried.
The hardest hit ar, Aceh, is considered to be a religiously conservative Islamic society and has had no tourism nor any Western presence in recent yrs due to armed conflict between the Indonesian military and Acehnese separatists. Some believe that the tsunami was divine punishment for lay Muslims shirking their daily prayers and/or following a materialistic lifestyle. Others have said that Allah was angry that there were Muslims killing other Muslims in an ongoing conflict.[103] Women in Aceh required a special approach from foreign aid acies, and continue to have unique needs.
The widesprd devastation caused by the tsunami led the main rebel group GAM to declare a cse-fire on December 28, 2004, followed by the Indonesian government, and the two groups resumed long-stalled pce talks, which resulted in a pce agreement signed August 15, 2005. The agreement explicitly cites the tsunami as a justifiion.[104]
The extensive international media coverage of the tsunami, and the role of mass media and journalists in reconstruction, were discussed by editors of newspapers and broadcast media in tsunami-affected ars, in special -conferences set up by the Asia Pacific Journalism Centre.[105]
The December 26, 2004 Asian Tsunami left both the people and government of India in a state of heightened alert. On December 30, 2004, four days after the tsunami, the Portland, Oregon-based company Terra Resrch notified the India government that its sensors indied there was a possibility of 7.9 to 8.1 magnitude tectonic shift in the next 12 hours between Sumatra and New Zland.[106] In response, the India Home Affairs minister announced that a fresh onslaught of ddly tidal waves were likely along the India southern coast and Andaman and Nicobar Islands, even as there was no sign of turbulences in the region.[106] The announcement erated panic in the Indian Ocn region and caused thousands to flee their homes, which resulted in jammed roads.[107] The announcement was a false alarm and the Home Affairs minister withdrew their announcement.[107] On further investigation, the India government lrned that the consulting company Terra Resrch was run from the home of a self-described rthquake forecaster who had no telephone listing and maintained a website where he sold copies of his detection system.[108] Three days after the announcement, Indian National Congress president Sonia Gandhi called Science & Technology minister Kapil Sibal to express her concern about Sibal's December 30 public warning being "hogwash".[109]
Another result of the tsunami, respective toward Indian culture, was the water that washed away centuries of sand from some of the ruins of a 1,200-yr-old lost city at Mahabalipuram on the south coast of India. The site, containing such notable structures as a half-buried granite lion nr a 7th century Mahablipuram temple and a relic depicting an elephant, is part of what archaeologists believe to be an ancient port city that was swallowed by the s hundreds of yrs ago.[110][111]
The tsunami had a severe humanitarian and political impact in Sweden. The hardest hit country outside Asia, 543 Swedish tourists, mainly in Thailand, died. With no single incident having killed more Swedish people since the battle of Poltava in 1709, the cabinet of Göran Persson was hvily criticized for lack of action. The event was examined by an independent inquiry, Katastrofkommissionen.[citation needed]

Info: 2004 Indian Ocn rthquake and tsunami

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