2004 Indian Ocean earthquake
The 2004 Indian Ocean earthquake
known by the scientific community as the Sumatra-Andaman earthquake
was an undersea earthquake
that occurred at 00:58:53 UTC
(07:58:53 local time) December
with an epicentre
off the west coast of Sumatra
. The earthquake triggered a series of devastating
that spread throughout the Indian
, killing large numbers of people and inundating coastal communities
and Southeast Asia
, including parts of Indonesia
, and Thailand
Although initial estimates have put the worldwide death toll at over 275,000
with thousands of others missing, recent analysis compiled lists a total
of 229,866 persons lost, including 186,983 dead and 42,883 missing.
The figure excludes 400 to 600 people who are believed
to have perished in Myanmar
which is more than that government's official
figure of only 61 dead.
The catastrophe is one of the deadliest disasters
in modern history
. The disaster is known in Asia
and in the
international media as the Asian Tsunami
, and also called the Boxing
, and the United Kingdom
as it took place on Boxing
. Coincidentally, the tsunami occurred exactly one year after the
2003 earthquake that devastated the southern Iranian
The magnitude of the earthquake was originally
recorded as 9.0 on the Richter scale, but has been upgraded
to between 9.1 and 9.3. At this magnitude, it is the second largest earthquake ever recorded
on a seismograph. This earthquake was also reported to
be the longest duration of faulting ever observed, lasting between 500 and
600 seconds, and it was large enough that it caused the entire planet to
vibrate at least half an inch, or over a centimetre. It also triggered earthquakes in other locations
as far away as Alaska.
The earthquake originated in the Indian Ocean just north
island, off the western coast of northern Sumatra. The resulting tsunami
devastated the shores of Indonesia, Sri Lanka, India, Thailand and other
countries with waves up to 30 m (100 ft). It caused serious damage
and deaths as far as the east coast of Africa, with
the furthest recorded death due to the tsunami occurring at Rooi Els in South
Africa, 8,000 km (5,000 mi) away from the epicentre. In total,
eight people in South Africa died due to abnormally high sea levels and
The plight of the many affected
people and countries prompted a widespread humanitarian
response. In all, the worldwide community donated more than US$7 billion
in humanitarian aid to those affected by the earthquake.
The earthquake was initially reported as moment magnitude,
Mw 9.0. (Notice that this is not the so-called Richter scale or local
magnitude scale, ML, which is known to saturate at higher magnitudes.) In
February 2005 some scientists revised the estimate of the magnitude to 9.3. Although the Pacific Tsunami Warning Center
has accepted these new numbers, the United States Geological Survey
has so far not changed its estimate of 9.1. The most recent studies in 2006
have obtained a magnitude of Mw 9.1 to 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 great earthquake. Reference: EERI Publication
2006-06, page 14 [www.eeri.org]
of the main earthquake was at 3.316°N, 95.854°E (3°19′N
95°51.24′E), approximately 160 km (100 mi) west
of Sumatra, at a depth of 30 km (19 mi) below mean sea level (initially reported as 10 km).
The earthquake itself (apart from the tsunami) was felt as far away as Bangladesh,
Singapore and the Maldives.
Indonesia lies between the Pacific Ring of Fire along the north-eastern
islands adjacent to and including New Guinea
and the Alpide belt along the south and west from Sumatra,
Java, Bali, Flores, and
Timor. The December 2004 earthquake actually occurred
within the Alpide belt.
Since 1900 the only earthquakes recorded with a greater
magnitude were the 1960 Great Chilean Earthquake (magnitude
9.5) and the 1964 Good Friday Earthquake in Prince William Sound (9.2). The only other
recorded earthquake of magnitude 9.0 or greater was off Kamchatka, Russia, on
November 4, 1952 (magnitude
9.0). Each of these megathrust earthquakes also spawned tsunamis
in the Pacific Ocean, but the death toll from these was significantly lower.
The worst of these caused only a few thousand deaths, primarily because
of the lower population density along the coasts near
affected areas and the much greater distances to more populated coasts.
Other very large megathrust earthquakes occurred in
Nazca Plate and South American Plate); 1827 (Colombia,
Nazca Plate and South American Plate); 1812 (Venezuela,
Caribbean Plate and South American Plate) and
1700 (Cascadia Earthquake, western U.S. and Canada, Juan de Fuca Plate and North American Plate). These are all believed
to have been of greater than magnitude 9, but no accurate measurements were
available at the time.
The earthquake was unusually large in geographical extent.
An estimated 1,200 km (750 mi) of faultline slipped about 15 m (50 ft)
along the subduction zone where the India
Plate dives under the Burma
Plate. The slip did not happen instantaneously but took place in two
phases over a period of several minutes. Seismographic and acoustic data
indicate that the first phase involved the formation of a rupture about
400 km (250 mi) long and 100 km (60 mi) wide, located
30 km (19 mi) beneath the sea bed—the longest rupture ever known
to have been caused by an earthquake. The rupture proceeded at a speed of
about 2.8 km/s (1.7 mi/s) or 10,000 km/h (6,300 mph),
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 2.1 km/s (1.3 mi/s) or 7,600 km/h (4,700 mph), continuing
north for another five minutes to a plate boundary where the fault changes
from subduction to strike-slip (the two plates push 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
The India Plate is part of the great Indo-Australian Plate, which underlies
the Indian Ocean and Bay
of Bengal, and is drifting north-east at an average of 6 cm/year
(2 inches per year). 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 slips 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 crust above and trigger melt which
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.
As well as the sideways movement between the plates,
the sea bed is estimated to have risen by several metres, displacing an
estimated 30 km³ (7 cu mi) of water and triggering devastating
tsunami waves. The waves did not originate from a point
source, as mistakenly depicted in some illustrations of their spread,
but radiated outwards along the entire 1,200 km (750 mi) length
of the rupture (acting as a line
source). This greatly increased the geographical area over which the
waves were observed, reaching as far as Mexico, Chile and the
Arctic. The raising of the sea bed significantly reduced
the capacity of the Indian Ocean, producing a permanent rise in the global
sea level by an estimated 0.1 mm.
Aftershocks and other earthquakes
Locations of initial earthquake and all aftershocks measuring greater
than 4.0 from December 26
The initial quake is indicated by the large star in the lower right square
of the grid. (Cr: USGS
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 of
magnitude 8.7 was located off the Sumatran island of Nias. A debate arose among seismologists over whether the
2005 Sumatra earthquake should be considered
an aftershock of the December 2004 event or a "triggered earthquake" (an
earthquake brought about by a previous earthquake), as it was larger than typical aftershocks but on
the same fault. Other aftershocks of up to magnitude 6.6 continued to shake
the region daily for up to three or four months. As well as continuing aftershocks,
the energy released by the original earthquake continued to make its presence
felt well after the event. A week after the earthquake, its reverberations
could still be measured, providing valuable scientific data about the Earth's
The 2004 Indian Ocean earthquake came just three days
after a magnitude 8.1 earthquake in an uninhabited region west of New Zealand's
sub-Antarctic Auckland Islands, and north of Australia's
Macquarie Island. This is unusual, since earthquakes
of magnitude 8 or more occur only about once per year on average. Some seismologists have speculated about a connection
between these two earthquakes, saying that the former one might have been
a catalyst to the Indian Ocean earthquake, as the two earthquakes happened
on opposite sides of the Indo-Australian Plate. However, the U.S. Geological Survey sees
no evidence of a causal relationship in this incident. Coincidentally, the
earthquake struck almost exactly one year (to the hour) after a 6.6 magnitude
earthquake killed an estimated 30,000 people in the city of Bam
in Iran on
December 26, 2003.
An earthquake of magnitude 8.7 was reported shortly
at 16:09:37 UTC (23:09:37 local time) on March 28,
2005, approximately at the same location (see 2005 Sumatran earthquake). It was likely
a very large aftershock of the original earthquake. This earthquake had
strong aftershocks of its own, including magnitude 6.0 and 6.1 earthquakes.
At 8.7 it ranks as the 7th largest earthquake since 1900. A 6.7 magnitude
earthquake struck on April 10, 2005, at 10:29
UTC (17:29 local time) about 120 km (75 mi) south-west of the city of Padang.
Some scientists confirm that the December earthquake
had activated Leuser Mountain, a volcano in Aceh province along
the same range of peaks as Mount
Talang, while the 2005 Sumatran earthquake had sparked
activity in Lake Toba, an ancient crater in Sumatra. Geologists say that the eruption of Mount
Talang in April 2005 is connected to the December earthquake.
Power of the earthquake
The total energy released by the 2004 Indian Ocean earthquake
has been estimated as 3.35 exajoules (3.35×1018
joules). This is equivalent to over 930 terawatt hours,
0.8 gigatons of TNT, or about as much energy as is used in the
United States in 11 days. However, the most reliable seismic energy release
estimate, as of September 30, 2005, is 1.1×1018
joules. This corresponds to about 0.25 gigatons of
TNT. The earthquake is estimated to have resulted in an oscillation of
the Earth's surface of about 20–30 cm (8–12 in), equivalent to
the effect of the tidal forces caused by the Sun and Moon. The shock waves
of the earthquake were felt across the planet; as far away as the U.S. state
where vertical movements of 3 mm (0.12 in) were recorded. The entire Earth's surface is estimated to have
moved vertically by up to 1 cm.
The shift of mass and the massive release of energy
very slightly altered the Earth's rotation. The exact amount is yet undetermined,
but theoretical models suggest the earthquake shortened the length of a
day by 2.68 microseconds (2.68 µs, or about one billionth
of the length of a day), due to a decrease in the oblateness
of the Earth. It also caused the Earth to minutely "wobble" on
its axis by up to 2.5 cm (1 in) in the direction of 145° east
longitude, or perhaps by up to 5 or 6 cm (2.0 to 2.4 in). However, because of tidal effects of the Moon, the length
of a day increases at an average of 15 µs
per year, so any rotational change due to the earthquake will be lost quickly.
Similarly, the natural Chandler wobble of the Earth can be up to 15 m (50 ft).
More spectacularly, there was 10 m (33 ft)
movement laterally and 4–5 m (13–16 ft) vertically along the fault
line. Early 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), may have moved south-west by up to 20 m (66 ft), and
some early estimates said up to 36 m (118 ft). However, more accurate
data released, more than a month following the earthquake, present a more
manageable figure of 20 cm (7.9 in). Since movement was vertical as well as lateral,
some coastal areas may have been moved to below sea level. The Andaman and Nicobar Islands appear
to have shifted south-west by around 1.25 m (4.1 ft) and to have
sunk by 1 m (3.28 ft).
In February 2005 the Royal
Navy vessel HMS Scott surveyed the seabed around
the earthquake zone, which varies in depth between 1,000 m and 5,000 m
(3,300 ft and 16,500 ft) west of Sumatra. The survey, conducted
using a high-resolution, multi-beam sonar system,
revealed that the earthquake had made a huge impact on the topography of
the seabed. Previous activity on the fault over geological periods of time
had created large thrust ridges, about 1,500 m high, which collapsed
in places during the earthquake to produce large landslides
several kilometres across. One landslide consisted of a single block of material
some 100 m high and 2 km long (300 ft by 1.25 mi). The
force of the displaced water was such that individual blocks of rock, massing
millions of tons apiece, were dragged as much as 10 km (7 mi) across
the seabed. An oceanic trench several kilometres wide was exposed
in the earthquake zone.
By a beneficial and remarkable coincidence, the TOPEX/Poseidon and Jason 1
satellites happened to pass over the tsunami as it was crossing the ocean. These satellites carry radars that
measure precisely the height of the water surface; anomalies of the order
of 50 cm (20 in) were measured. Measurements from these satellites
may prove invaluable for the understanding of the earthquake and tsunami. Unlike data from tide gauges
installed on shores, measurements obtained in the middle of the ocean can
be used for computing the parameters of the source earthquake without having
to compensate for complex effects close to the coast. Inversion of this
height data may help adjust the parameters for the source earthquake.
Animation of the tsunami caused
by the earthquake showing how the tsunami radiated from the entire length
of the 1,200 kilometer (750 mi) rupture.
The sudden vertical rise of the seabed by several metres
during the earthquake displaced massive volumes of water, resulting in a
tsunami that struck the coasts of the Indian Ocean.
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 seabed than by horizontal motion.
The tsunami, like all others, behaved very differently
in deep water than in shallow water. In deep ocean water, tsunami waves
form only a small hump, barely noticeable and harmless, which generally
travels at a very high speed of 500 to 1,000 km/h (310 to 620 mph);
in shallow water near 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 reached a height of 24 m
(80 ft) when coming ashore along large stretches of the coastline,
rising to 30 m (100 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 maximum height was
60 cm (2 ft). These are the first such observations
ever made. However, these observations could not have been used to provide
a warning, because the satellites were not intended for that purpose and
the data took hours to analyse.
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 (20 petajoules). 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
released in the earthquake itself. In many places the waves reached as far
as 2 km (1.24 mi) inland.
Because the 1,200 km (745.6 mi) of faultline
affected by the earthquake was in a nearly north-south orientation, the
greatest strength of the tsunami waves was in an east-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 near the epicentre. It also benefited from the fact that the earthquake
proceeded more slowly in the northern rupture zone, greatly reducing the
energy of the water displacements in that region.
Coasts that have a landmass between them and the tsunami's
location 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 is 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 reach the various coastlines. The northern regions of the Indonesian island of
Sumatra were hit very quickly, while Sri Lanka and the east coast of India
were hit roughly 90 minutes 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
Sea off its western coast.
The tsunami was noticed as far as Struisbaai
in South Africa, some 8,500 km (5,300 mi)
away, where a 1.5 m (5 ft) high tide surged on shore about 16
hours after the earthquake. It took a relatively long time to reach 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 east to west. The tsunami also reached Antarctica,
where tidal gauges at Japan's Syowa
Base recorded oscillations of up to a meter, with disturbances lasting
a couple of days.
Some of the tsunami's energy escaped into the Pacific
Ocean, where it produced small but measurable tsunamis along the western
coasts of North and South America, typically around 20 to 40 cm (7.9 to 15.7 in). At Manzanillo, Mexico, a
2.6 m (8.5 ft) crest-to-trough tsunami was measured. This puzzled
many scientists, as the tsunamis measured in some parts of South America
were larger than those measured in some parts of the Indian Ocean. It has
been theorised that the tsunamis were focused and directed at long ranges
by the mid-ocean ridges which run along the margins
of the continental plates.
Signs and warnings
Despite a lag of up to several hours between the earthquake
and the impact of the tsunami, nearly all of the victims were taken completely
by surprise. There were no tsunami warning systems in the Indian
Ocean to detect tsunamis or to warn the general populace living around the
ocean. Tsunami detection is not easy 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 communications infrastructure to issue timely warnings
is an even bigger problem, particularly in a relatively poor part of the
Tsunamis are much more frequent in the Pacific Ocean
because of earthquakes 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 Ocean (the point where
this earthquake struck), no warning system exists in that ocean. Tsunamis
there are relatively rare despite earthquakes being relatively frequent
in Indonesia. The last major tsunami was caused by the Krakatoa
eruption of 1883. It should be noted that not every earthquake produces
large tsunamis; on March 28, 2005, a magnitude
8.7 earthquake hit roughly the same area of the Indian Ocean 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 Ocean. The United Nations started working on an Indian Ocean Tsunami Warning
System and by 2005 had the initial steps in place. Some have even proposed
creating a unified global tsunami warning system, to include the Atlantic Ocean and Caribbean.
Maximum recession of tsunami waters at Kata Noi Beach
before the third, and strongest, tsunami wave (sea visible in the right corner,
the beach is at the extreme left), 10:25 a.m. local time.
The first warning sign of a possible tsunami is the
earthquake itself. However, tsunamis can strike thousands of miles away where
the earthquake is only felt weakly or not at all. Also, in the minutes preceding
a tsunami strike, the sea often recedes temporarily from the coast. People
in Pacific regions are more familiar with tsunamis and often recognise this
phenomenon as a sign to head for higher ground.
around the Indian Ocean, this rare sight reportedly induced people, especially
children, to visit the coast to investigate and collect stranded fish on
as much as 2.5 km (1.6 mi) of exposed beach, with fatal results.
One of the few coastal areas to evacuate ahead of the
tsunami was on the Indonesian island of Simeulue,
very close to the epicentre. Island folklore recounted an earthquake and
tsunami in 1907, and the islanders fled to inland hills after the initial
shaking yet before the tsunami struck. On Maikhao beach in northern Phuket, Thailand,
a 10-year-old British girl named Tilly
Smith had studied tsunamis in geography class at school and recognised
the warning signs of the receding ocean and frothing bubbles. She and her
parents warned others on the beach, which was evacuated safely. John
Chroston, a biology teacher from Scotland, also recognised the signs
at Kamala Bay north of Phuket, taking a busload of vacationers and locals
to safety on higher ground.
Retreat and rise cycle
The tsunami was a succession of several waves, occurring
in retreat and rise cycles with a period of over 30 minutes between each
peak. The third wave was the most powerful and reached highest, occurring
about an hour and a half after the first wave. Smaller tsunamis continued
to occur for the rest of the day.
Receding waters after the second tsunami, 10:20
3rd tsunami wave, 11:00 a.m.
4th tsunami wave, 11:22 a.m.
Damage and casualties
The U.S. Geological Survey initially recorded
the toll as 283,100 killed, 14,100 missing, and 1,126,900 people
displaced. Early news reports after the earthquake spoke of a toll in the
hundreds, but the numbers rose steadily over the following week. However,
more recent figures indicate that the actual casualties were 186,983 dead
and 42,883 missing, for a total of 229,866, as more and more displaced
survivors have been found and name duplications eliminated from the lists
of victims. Measured in lives lost, this is one of the ten worst earthquakes in recorded history, as
well as the single worst tsunami in history.
Relief agencies report that one-third of the dead appear
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
least 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 beach for the fishermen to
return and looking after their children in the houses.
In addition to the large number of local residents,
up to 9,000 foreign tourists (mostly Europeans) enjoying the peak holiday
travel season were among the dead or missing, especially people from the
Nordic countries. The European nation hardest
hit may have been Sweden, whose death toll was 428 dead, with 116 missing.
States of emergency were declared in Sri Lanka,
Indonesia, and the Maldives.
The United Nations has declared that the current
relief operation will be the costliest ever. UN Secretary-General Kofi Annan
has stated that reconstruction would probably take between five and ten
years. Governments and non-governmental organisations
fear the final death toll may double as a result of diseases, prompting
a massive humanitarian
For purposes of establishing timelines of local events,
zones of affected areas are: UTC+3: (Kenya, Madagascar, Somalia, Tanzania);
UTC+4: (Mauritius, Réunion, Seychelles); UTC+5: (Maldives); UTC+5:30:
(India); UTC+6: (Bangladesh, Sri Lanka); UTC+6:30: (Cocos Islands, Myanmar);
UTC+7: (Indonesia (western), Thailand); UTC+8: (Malaysia, Singapore). Since
the earthquake occurred at 00:58:53 UTC, add the above
offsets to find the local time of the earthquake.
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 number in this column is the same as reported
2 Does not include approximately 19,000 missing people initially
declared by Tamil Tiger authorities from regions under their
3 Data includes at least 2,464 foreigners.
4 Does not include South African citizens who died outside
of South Africa (eg, tourists in Thailand). For more information on those
deaths, see this
Countries most affected by the 2004 Indian Ocean earthquake.
The earthquake and resulting tsunami affected many countries
in Southeast 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 numbers of
citizens traveling in the region on holiday. Countries like Sweden and Germany
lost over 500 citizens in the disaster.
Casualties in historical context
was the fourth most powerful earthquake recorded since 1900, and the confirmed
death toll is just under 200,000 due to the ensuing
tsunami. The deadliest earthquakes since 1900 were the Tangshan, China earthquake of 1976, in which
at least 255,000 were killed; the earthquake of 1927 in Xining, Qinghai,
China (200,000); the Great Kanto earthquake which struck Tokyo in 1923
(143,000); and the Gansu, China, earthquake of 1920 (200,000). The deadliest
known earthquake in history occurred in 1556 in Shaanxi, China, with an estimated
death toll of 830,000, though figures from this time period may not be reliable.
The 2004 tsunami is the deadliest in recorded history.
Prior to 2004, the deadliest recorded tsunami in the Pacific
Ocean was in 1782, when 40,000 people were killed by a tsunami in the
South China Sea. The tsunami created by the 1883 eruption of Krakatoa
is thought to have resulted in 36,000 deaths. The most deadly tsunami
between 1900 and 2004 occurred in 1908 in Messina,
Italy, on the Merranean Sea, where the earthquake and tsunami
killed 70,000. The most deadly tsunami in the Atlantic Ocean resulted from the 1755 Lisbon earthquake, which, combined
with the toll from the actual earthquake and resulting fires, killed over
The 2004 earthquake and tsunami seem to be the deadliest
natural disaster since either the 1976 Tangshan earthquake or the 1970 Bhola cyclone, or could conceivably
exceed both of these. Because of uncertainty over death tolls, it might never
be known for sure which of these natural disasters was the deadliest.
See also: Library
damage resulting from the 2004 Indian Ocean earthquake
Human component in magnitude of damage
A village near the coast of Sumatra
lies in ruin on January 2
. 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
The human destruction of coral
reefs played a significant role in 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 beaches, and
instead make way for shrimp farms and other economic choices. On the Surin
Island chain of Thailand's coast, many people were saved as the tsunami
rushed against the coral reefs protecting the islands. However, there were
many fewer people on these islands, which helps explain the lower death toll.
Many reefs areas around the Indian Ocean have been exploded with dynamite
because they are considered impediments to shipping, an important part of
the South Asian economy. Similarly, the removal of coastal mangrove
trees is believed to have intensified the effect of the tsunami in some locations.
These trees, which lined the coast but were removed to make way for coastal
residences, might have blocked the force of the tsunami. Another factor is
the removal of coastal sand dunes.
Humanitarian, economic and environmental impact
A great deal of humanitarian aid was needed because of widespread
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 areas. The
main concern of humanitarian and government agencies was to provide sanitation
facilities and fresh drinking water to contain the spread of diseases such
typhoid and hepatitis
A and B.
There was also a great concern that the death toll could
rise further as diseases and hunger spread. However, because of the initial
quick response, this was minimised.
In the days after the event, significant effort was
spent in burying
bodies hurriedly for fear of disease. However, the public
health risks may have been exaggerated, and therefore this may not have
been the best way to allocate resources. The World Food Programme provided food aid
to more than 1.3 million people affected by the tsunami.
- Further information: Dead bodies and health risks
Nations 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 (increased to US$350 million), and the World
Bank offering US$250 million. 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
President Bush asked Congress to increase 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 lead a U.S. effort
to provide private aid to the tsunami victims.
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 generous. Lots of charities were given considerable donations
from the public. For example, in the UK the public donated roughly £330,000,000
sterling (nearly US$600,000,000). This considerably outweighed the donation
by the government and came to about £5.50 (US$10) donated by each
and every citizen.
In August 2006, fifteen local aid staff working on post-tsunami
rebuilding have been found executed in northeast Sri Lanka after heavy fighting,
the main umbrella body for aid agencies in the country said. There had been
reports and rumors that the local aid workers had been killed.
The impact on coastal fishing communities and fisherfolk, some of
the poorest people in the region, has been devastating with high losses
of income earners as well as boats and fishing gear. In Sri Lanka artisanal fishery, where the use of
fish baskets, fishing traps, and spears 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
years the fishery industry has emerged as a dynamic export-oriented sector,
generating substantial foreign exchange earnings. Preliminary estimates
indicate 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.
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 areas drinking water
supplies and farm fields may have been contaminated for years by salt water
from the ocean.
Both the earthquake and the tsunami may have affected
shipping in the Malacca Straits by changing the depth of the
seabed and by disturbing navigational buoys and old shipwrecks. Compiling
new navigational charts may take months or years.
Countries in the region appealed to tourists to return,
pointing out that most tourist infrastructure is undamaged. However, tourists
were reluctant to do so for psychological reasons. Even resorts on the Pacific
coast of Thailand, which were completely untouched, were hit by cancellations.
One year after the tsunami hit, tourism is beginning to climb again, with
a full recovery expected sometime in 2006.
Tsunami Inundation, Khao Lak
, North of Phuket
ASTER Images and SRTM Elevation Model.
Beyond the heavy toll on human lives, the Indian Ocean
earthquake has caused an enormous environmental impact that will affect
the region for many years to come. It has been reported that severe damage
has been inflicted on ecosystems such as mangroves,
coral reefs, forests, coastal
and rock formations, animal and plant biodiversity
and groundwater. In addition, the spread of solid and
liquid waste and industrial chemicals, water pollution and the destruction of sewage collectors
and treatment plants threaten the environment even further, in untold ways.
The environmental impact will take a long time and significant resources
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 sea waves are totally without fresh water and
could be rendered uninhabitable for decades. Uncountable wells that served
communities were invaded by sea, sand and earth; 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 death of plants and important soil micro-organisms. Thousands
of rice, mango and banana plantations in Sri Lanka were destroyed almost
entirely and will take years 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. UNEP has decided to earmark a US$1,000,000 emergency
fund and to establish a Task Force to respond to requests for technical
assistance from countries affected by the tsunami. 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 Great Barrier Reef, in Australia's north-eastern
Many health professionals and aid workers have reported
widespread 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 dead. Some psychologists interpret this as evidence
of psychological trauma.
The hardest hit area, Aceh, is considered
to be a religiously conservative Islamic society
and has had no tourism nor any Western presence in recent years due to armed
conflict between the Indonesian military and Acehnese separatists. Some believe that the
tsunami was 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. In what may be the most significant positive result
of the tsunami, the widespread devastation led the main rebel group GAM to declare a cease-fire on December
followed by the Indonesian government, and the two groups resumed long-stalled
peace talks, which resulted in a peace agreement signed August 15,
2005. The agreement explicitly cites the tsunami as a justification.
The extensive international media coverage of the tsunami,
and the role of mass media and journalists in reconstruction, were discussed
by ors of newspapers and broadcast media in tsunami-affected areas, in special
video-conferences set up by the Asia Pacific Journalism Centre.
In another positive note of the tsunami, the water washed
away centuries of sand from some of the ruins of a 1,200-year-old lost city
at Mahabalipuram on the south coast of India. The
site, containing such notable structures as a half-buried granite lion near
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 sea hundreds of years ago.
Notes and references
- ^ UN Office of the Envoy for Tsunami Recovery.
- ^ "Myanmar is withholding
true casualties figures, says Thai priest". A missioner in Ranong,
a town on the border between Thailand and Myanmar, says locals talk about
600 victims. Burmese political dissidents say the same. AsiaNews.it.
January 4, 2005. URL accessed
- ^ Walton, Marsha. "Scientists:
Sumatra quake longest ever recorded." CNN. May 20, 2005.
- ^ West, Michael; Sanches, John J.; McNutt, Stephen R. "Periodically
Triggered Seismicity at Mount Wrangell, Alaska, After the Sumatra Earthquake."
Science. Vol. 308, No. 5725, 1144-1146.
May 20, 2005.
- ^ McKee, Maggie. "Power of tsunami
earthquake heavily underestimated." New
Scientist. February 9, 2005.
- ^ "Kamchatka
Earthquake, November 4, 1952." United States Geological Survey.
- ^ Kostel, Ken; Tobin, Mary. "The Sound of
a Distant Rumble: Researchers Track Underwater Noise Generated by December
26 Earthquake." Lamont-Doherty Earth Observatory. July 20,
- ^ Bilham, Roger. "A Flying
Start, Then a Slow Slip." Science. Vol. 308, No. 5725, 1126-1127.
May 20, 2005.
- ^ MarketWatch. "8.7
quake jars Sumatra, at least 300 dead." Investors.com. March 28,
- ^ McKernon, Conor. Science and Engineering
at The University of Edinburgh School of Geosciences. Retrieved on 2006-04-22.
- ^ USGS Earthquake Hazards
- ^ Earthquake-Tsunami
Event of Christmas/Boxing Day 2004: Frames of Alternative Analysis or Perception.
Retrieved on 2006-04-22.
- ^ Staff Writer. "Sumatra shaken
by new earthquake." BBC News.
April 10, 2005.
- ^ "Panic
in Sumatra after new earthquake." WIKINEWS. April 10,
- ^ Rinaldo, Aditya. "Thousands
flee as Indonesian volcano spews into life." Hindustan Times.
April 12, 2005.
- ^ Johnston, Tim (April 13,
2005). Indonesian Volcanoes
Erupt; Thousands Evacuated. VOA News. Retrieved on 2006-04-22.
- ^ Staff Writer. "Earthquake
felt in Oklahoma, too." MuskogeePhoenix.com. December
- ^ Cook-Anderson, Gretchen; Beasley, Dolores. "NASA
Details Earthquake Effects on the Earth." National Aeronautics
and Space Administration (press release). January
- ^ Schechner, Sam. "Earthquakes vs. the Earth's Rotation."
- ^ Staff Writer. "Italian
scientists say Asian quakes cause Earth's axis shifted." Xinhua. December
- ^ Staff Writer. "Quake moved Sumatra by only 20 centimeters:
Danish scientists", Agence France Presse, January
- ^ Bagla, Pallava. "After the Earth Moved", Science Now,
January 28, 2005.
- ^ Knight, Will. "Asian tsunami seabed
pictured with sonar." New
Scientist. February 10, 2005.
- ^ Staff Writer. "NASA/French
Satellite Data Reveal New Details of Tsunami." Jet Propulsion Laboratory/National Aeronautics
and Space Administration. January
- ^ TOPEX/Poseidon
Satellite Data on the December
tsunami in the Indian Ocean. Aviso.
- ^ Lorca, Emilio, Recabarren, Margot (1997). Eartquakes
- ^ Paulson, Tom. "New
findings super-size our tsunami threat." Seattlepi.com. February
- ^ Leslie, John. "NOAA Scientists
able to Measure Tsunami Height from Space." NOAA Magazine. January
- ^ McKee, Maggie. "Radar satellites
capture tsunami wave height." New
Scientist. January 6, 2005.
- ^ Pearce, Fred; Holmes, Bob. "Tsunami:
The impact will last for decades." New
Scientist. January 15, 2005.
- ^ Time travel map: Tsunami Laboratory, Novosibirsk,
- ^ Time travel map: Active Fault
Research Center: National Institute of Advanced Industrial Science and Technology,
- ^ "Indian
Ocean Tsunami" at Syowa Station, Antarctica, Hydrographic and Oceanographic
Dept. Japan Coast Guard.
- ^ Indian
Ocean Tsunami of 26 December, 2004. West Coast/Alaska Tsunami Warning
Center (USGS). December 31, 2004.
- ^ Carey, Bjorn. "Tsunami
Waves Channeled Around the Globe in 2004 Disaster." LiveScience.
August 25, 2005.
- ^ Block, Melissa. "Sri
Lankans Seek Lost Relatives After Tsunami." All Things Considered/NPR. December
- ^ Campbell, Matthew; Loveard, Keith; et al. "Tsunami
disaster: Focus: Nature's timebomb." Times Online. January
- ^ Staff Writer. "Girl,
10, used geography lesson to save lives." news.telegraph. January
- ^ Staff Writer. "Most tsunami
dead female - Oxfam." BBC News.
March 26, 2005.
- ^ Staff Writer. "Sweden's tsunami death
toll reaches 428." The Local: Sweden's News in English. May 19, 2005.
- ^ Most
Destructive Known Earthquakes on Record in the World (Earthquakes with 50,000
or More Deaths). United States Geological Survey.
- ^ (Japanese)Not
Awa, Japan 1703, alleged 100,000, which is probably a misreading of the 10,000
toll given in Watanabe, H., 1998, "Nihon higai tsunami so_ran, dai ni-han
" (Comprehensive list of destructive tsunamis to hit the Japanese islands,
2ndion): Tokyo, University of Tokyo Press, p. 238
- ^ a b Browne, Andrew. "Tsunami's Aftermath:
On Asia's Coasts, Progress Destroys Natural Defenses", Wall Street Journal,
- ^ Staff Writer. "UN upbeat on
tsunami hunger aid." BBC News.
January 9, 2005.
- ^ United Nations:
World Food Programme: Report on the Tsunami Crisis.
- ^ Staff Writer (01-27-2005). Tsunami aid:
Who's giving what. Retrieved on 2006-04-22.
- ^ Staff Writer. "Clinton,
Bush: Tsunami Aid Helping." The Early Show/CBS News.
- ^ Staff Writer. "Tsunami aid
shortfall over $4bn." BBC News.
March 18, 2005.
- ^ "Sri
Lanka aid workers 'executed'", CNN, 2006-08-06.
- ^ Staff Writer. "Indian Ocean Tsunamis Devastate
Fisherfolk." UK Agricultural Biodiversity Coalition. December
- ^ Staff Writer. "[Food Supply and Food Security Situation
in Countries Affected by the Asia Tsunami]." Food and Agriculture Organization
of the United Nations. January
- ^ Pearce, Fred. "Tsunami's salt
water may leave islands uninhabitable." New
Scientist. January 5, 2005.
- ^ Staff Writer. "Tsunami redrew ship channels,
ocean floor." MSNBC/Associated Press. January
- ^ Staff Writer. "Tsunami
tourism on track, but not quite fully recovered." USA Today/Associated Press. December
- ^ Staff Writer. "Impact of Tsunamis on Ecosystems."
UN Atlas of the Oceans. Accessed: March 10,
- ^ Falt, Eric. "Environmental
Issues Emerging from Wreckage of Asian Tsunami." United Nations Environment
- ^ United
Nations Environment Programme; Environment for Development. Retrieved
- ^ Broadway, Bill. "Divining
a Reason for Devastation." Washington Post. January
- ^ Memorandum
of Understanding between Indonesian government and the Free Aceh Movement,
August 15, 2005. (PDF)
- ^ Staff Writer. "Tsunami
waves exposed remnants of lost city." New
Scientist. February 26, 2005.
- ^ Staff Writer. "India finds more
'tsunami gifts'." BBC News.
February 27, 2005.
Photos and video