The tsunami that struck Malé in the Maldives on December 26, 2004.
A tsunami (pronounced /tsʊˈnɑːmi/ or /sʊˈnɑːmi/) is a series of
waves created when a body of water, such as an ocean is rapidly displaced
on a massive scale. Earthquakes, mass movements above or below water, volcanic
eruptions and other underwater explosions, landslides and large meteorite
impacts all have the potential to generate a tsunami. The effects of a tsunami
can range from unnoticeable to devastating. The term tsunami comes
from the Japanese language meaning harbour ("tsu", 津) and wave
("nami", 波). Although in Japanese tsunami is used for both the singular
and plural, in English tsunamis is often used as the plural. The term
was created by fishermen who returned to port to find the area surrounding
their harbour devastated, although they had not been aware of any wave in
the open water. Tsunamis are common throughout Japanese history, as 195 events
in Japan have been recorded.
A tsunami has a much smaller amplitude (wave heights)
offshore, and a very long wavelength (often hundreds of kilometres long),
which is why they generally pass unnoticed at sea, forming only a passing
"hump" in the ocean. Tsunamis have been historically referred to as tidal
waves because as they approach land, they take on the characteristics
of a violent onrushing tide rather than the sort of cresting waves that are
formed by wind action upon the ocean (with which people are more familiar).
Since they are not actually related to tides the term is considered misleading
and its usage is discouraged by oceanographers.  Since not all tsunamis
occur in harbours, however, that term is equally misleading, although it
does have the benefit of being misleading in a different language.
Tsunamis can be generated when the sea floor abruptly
deforms and vertically displaces the overlying water. Such large vertical
movements of the Earth’s crust can occur at plate boundaries. Subduction
earthquakes are particularly effective in generating tsunamis. As an oceanic
plate is subducted beneath a continental plate, it sometimes brings down
the lip of the continental with it. Eventually, too much stress is put on
the lip and it snaps back, sending shockwaves through the Earth’s crust,
causing a tremor under the sea, known as an undersea earthquake.
Submarine landslides (which are sometimes triggered by
large earthquakes) as well as collapses of volcanic edifices may also disturb
the overlying water column as sediment and rocks slide downslope and are
redistributed across the sea floor. Similarly, a violent submarine volcanic
eruption can uplift the water column and form a tsunami.
Tsunamis are surface gravity waves that are formed as
the displaced water mass moves under the influence of gravity and radiate
across the ocean like ripples on a pond.
In the 1950s it was discovered that larger tsunamis than
previously believed possible could be caused by landslides, explosive volcanic
action, and impact events. These phenomena rapidly displace large volumes
of water, as energy from falling debris or expansion is transferred to the
water into which the debris falls. Tsunamis caused by these mechanisms, unlike
the ocean-wide tsunamis caused by some earthquakes, generally dissipate quickly
and rarely affect coastlines distant from the source due to the small area
of sea affected. These events can give rise to much larger local shock waves
(solitons), such as the landslide at the head of Lituya Bay which produced
a water wave estimated at 50 – 150 m and reached 524 m up local
mountains. However, an extremely large landslide could generate a megatsunami
that might have ocean-wide impacts.
The geologic recorded tells us that there have been massive
tsunamis in Earth's past. These tsunamis were so large that they caused landslides
on the opposite coast triggering another massive tsunami or "bounce back"
tsunami. An example today would be a landslide equivalent to everything
west of Portland falling in to the Pacific ocean, resulting in a tsunami
that hits the Chinese coast with enough force to erode the coast and trigger
a landslide large enough to send a tsunami that would inundate the US west
coast and wipe out Portland.
There is a common misconception that tsunamis behave like wind-driven waves
or swells (with air behind them, as in this celebrated 19th century woodcut
by Hokusai). In fact, a tsunami is better understood as a new and suddenly
higher sea level, which manifests as a shelf or shelves of water. The leading
edge of a tsunami superficially resembles a breaking wave but behaves differently:
the rapid rise in sea level, combined with the weight and pressure of the
ocean behind it, has far greater force.
Often referred to as "tidal waves", a tsunami does not
look like the popular impression of "a normal wave, only much bigger". Instead
it looks rather like an endlessly onrushing tide which forces its way around
and through any obstacle. Most of the damage is caused by the huge mass of
water behind the initial wave front, as the height of the sea keeps rising
fast and floods powerfully into the coastal area. The sheer weight of water
is enough to pulverise objects in its path, often reducing buildings to their
foundations and scouring exposed ground to the bedrock. Large objects such
as ships and boulders can be carried several miles inland before the tsunami
Tsunamis act very differently from typical surf swells:
they contain immense energy, propagate at high speeds and can travel great
trans-oceanic distances with little overall energy loss. A tsunami can cause
damage thousands of kilometres from its origin, so there may be several hours
between its creation and its impact on a coast, arriving long after the seismic
wave generated by the originating event arrives. Although the total or overall
loss of energy is small, the total energy is spread over a larger and larger
circumference as the wave travels. The energy per linear metre in the wave
is proportional to the inverse of the distance from the source.
(In other words, it decreases
linearly with distance.) This is the two-dimensional equivalent of the inverse
square law, which is followed by waves which propagate in three dimensions
(in a sphere instead of a circle).
A single tsunami event may involve a series of waves
of varying heights; so the set of waves is called a train. In open
water, tsunamis have extremely long periods (the time for the next wave top
to pass a point after the previous one), from minutes to hours, and long wavelengths
of up to several hundred kilometres. This is very different from typical
wind-generated swells on the ocean, which might have a period of about 10
seconds and a wavelength of 150 metres.
The height of a tsunami wave in open water is often less
than one metre, and the height is spread over the wavelength of the tsunami
which is multiple kilometres. This is unnoticeable to people on ships in
deep water. Because it has such a large wavelength, the energy of a tsunami
mobilizes the entire water column down to the sea bed. Typical ocean surface
waves in deep water cause water motion to a depth equal to half their wavelength.
This means, ocean surface wave motion will only reach down to a depth of a
few 100 m or less. Tsunamis, by contrast, behave as 'shallow water waves'
in the deep ocean.
Because a tsunami behaves like a 'shallow water wave,'
its speed is based on the depth of the water. Typically, a tsunami wave will
travel across a deep ocean at an average speed of 400 to 500 mph.().
As the wave approaches land, the sea shallows and the tsunami wave no longer
travels as quickly, so it begins to 'pile-up'; the wave-front becomes steeper
and taller, and there is less distance between crests. While a person at the
surface of deep water would probably not even notice the tsunami, the wave
can increase to a height of six stories or more as it approaches the coastline
and compresses. The steepening process is analogous to the cracking of a
tapered whip. As a wave goes down the whip from handle to tip, the same energy
is deposited in less and less material, which then moves more violently as
it receives this energy.
A wave becomes a 'shallow-water wave' when the ratio
between the water depth and its wavelength gets very small, and since a tsunami
has an extremely large wavelength (hundreds of kilometres), tsunamis act as
a shallow-water wave even in deep oceanic water. Shallow-water waves move
at a speed that is equal to the square root of the product of the acceleration
of gravity (9.8 m/s2) and the water depth. For example, in
the Pacific Ocean, where the typical water depth is about 4000 m, a tsunami
travels at about 200 m/s (720 km/h or 450 mph) with little
energy loss, even over long distances. At a water depth of 40 m, the
speed would be 20 m/s (about 72 km/h or 45 mph), which is
much slower than the speed in the open ocean but the wave would still be
difficult to outrun.
Tsunamis propagate outward from their source, so coasts
in the "shadow" of affected land masses are usually fairly safe. However,
tsunami waves can diffract around land masses (as shown in this Indian Ocean
tsunami animation as the waves reach southern Sri Lanka and India). It's also
not necessary that they are symmetrical; tsunami waves may be much stronger
in one direction than another, depending on the nature of the source and the
Local geographic peculiarities can lead to seiche or
standing waves forming, which can amplify the onshore damage. For instance,
the tsunami that hit Hawaii on April 1, 1946 had a fifteen-minute interval
between wave fronts. The natural resonant period of Hilo Bay is about thirty
minutes. That meant that every second wave was in phase with the motion of
Hilo Bay, creating a seiche in the bay. As a result, Hilo suffered worse damage
than any other place in Hawaii, with the tsunami/seiche reaching a height
of 14 m and killing 159 inhabitants.
Ocean waves are normally divided into 3 groups, characterized
- Deep water
- Intermediate water
- Shallow water
Even though a tsunami is generated in deep water (around
4000 m below mean sea level), tsunami waves are considered shallow-water
waves. As the tsunami wave approaches the shallow waters of shore, its time
period remains the same, but its wavelength decreases rapidly, thus causing
the water to pile up to form tremendous crests, in an effect known as "shoaling".
Signs of an approaching tsunami
The following have at various times been associated with
a tsunami :
- An earthquake may be felt.
- Large quantities of gas may bubble to the water
surface and make the sea look as if it is boiling.
- The water in the waves may be unusually hot.
- The water may smell of rotten eggs (hydrogen sulfide),
petrol, or oil.
- The water may sting the skin.
- A thunderous boom may be heard followed by
- a roaring noise as of a jet plane
- or a noise akin to the periodic whop-whop of
- or a whistling sound.
- The sea may recede to a considerable distance.
- A flash of red light might be seen near the horizon.
Warnings and prevention
Tsunamis cannot be prevented or precisely predicted,
but there are some warning signs of an impending tsunami, and there are many
systems being developed and in use to reduce the damage from tsunamis.
In instances where the leading edge of the tsunami wave
is its trough, the sea will recede from the coast half of the wave's period
before the wave's arrival. If the slope is shallow, this recession can exceed
many hundreds of metres. People unaware of the danger may remain at the shore
due to curiosity, or for collecting fish from the exposed sea bed.
Tsunami warning sign on seawall in Kamakura, Japan, 2004. In the Muromachi
period, a tsunami struck Kamakura, destroying the wooden building that housed
the colossal statue of Amida Buddha at Kotokuin. Since that time, the statue
has been outdoors.
In instances where the leading edge of the tsunami is
its first peak, succeeding waves can lead to further flooding. Again, being
educated about a tsunami is important, to realize that when the water level
drops the first time the danger is not yet over. In a low-lying coastal area,
a strong earthquake is a major warning sign that a tsunami may be produced.
Regions with a high risk of tsunamis may use tsunami
warning systems to detect tsunamis and warn the general population before
the wave reaches land. In some communities on the west coast of the United
States, which is prone to Pacific Ocean tsunamis, warning signs advise people
where to run in the event of an incoming tsunami. Computer models can roughly
predict tsunami arrival and impact based on information about the event that
triggered it and the shape of the seafloor (bathymetry) and coastal land (topography).
One of the early warnings comes from nearby animals.
Many animals sense danger and flee to higher ground before the water arrives.
The Lisbon quake is the first documented case of such a phenomenon in Europe.
The phenomenon was also noted in Sri Lanka in the 2004 Indian Ocean earthquake.
 Some scientists speculate that animals may have an ability to sense subsonic
Rayleigh waves from an earthquake minutes or hours before a tsunami strikes
shore (Kenneally, ).
While it is not possible to prevent a tsunami, in some
particularly tsunami-prone countries some measures have been taken to reduce
the damage caused on shore. Japan has implemented an extensive programme of
building tsunami walls of up to 4.5 m (13.5 ft) high in front of populated
coastal areas. Other localities have built floodgates and channels to redirect
the water from incoming tsunamis. However, their effectiveness has been questioned,
as tsunamis are often higher than the barriers. For instance, the tsunami
which hit the island of Hokkaido on July 12, 1993 created waves as much as
30 m (100 ft) tall - as high as a 10-story building. The port town of Aonae
was completely surrounded by a tsunami wall, but the waves washed right
over the wall and destroyed all the wood-framed structures in the area. The
wall may have succeeded in slowing down and moderating the height of the
tsunami but it did not prevent major destruction and loss of life.
The effects of a tsunami can be mitigated by natural
factors such as tree cover on the shoreline. Some locations in the path of
the 2004 Indian Ocean tsunami escaped almost unscathed as a result of the
tsunami's energy being sapped by a belt of trees such as coconut palms and
mangroves. In one striking example, the village of Naluvedapathy in India's
Tamil Nadu region suffered minimal damage and few deaths as the wave broke
up on a forest of 80,244 trees planted along the shoreline in 2002 in a bid
to enter the Guinness Book of Records.  Environmentalists have suggested
tree planting along stretches of sea coast which are prone to tsunami risks.
While it would take some years for the trees to grow to a useful size, such
plantations could offer a much cheaper and longer-lasting means of tsunami
mitigation than the costly and environmentally destructive method of erecting
See also List of historic tsunamis by death toll.
Tsunamis occur most frequently in the Pacific Ocean,
but are a global phenomenon; they are possible wherever large bodies of water
are found, including inland lakes, where they can be caused by landslides.
Very small tsunamis, non-destructive and undetectable without specialized
equipment, occur frequently as a result of minor earthquakes and other events.
Japan is a nation with the most recorded tsunamis in
the world. The earliest recorded disaster being that of the 684 A.D. Hakuho
Quake. The number of tsunamis in Japan totals 195 over a 1,313 year period,
averaging one event every 6.7 years, the highest rate of occurrence in the
world. These waves have hit with such violent fury that entire towns have
been destroyed. In 1896 Sanriku, Japan, with a population of 20,000, suffered
such a devastating fate.
On December 26, 2004, an undersea earthquake measuring
9.0 on the Richter scale occurred 160 km (100 mi) off the western coast
of Sumatra, Indonesia. It was the fifth largest earthquake in recorded history
and generated massive tsunamis, which caused widespread devastation when they
hit land, leaving an estimated 230,000 people dead in countries around the
1700 - Vancouver Island, Canada
January 26 - The Cascadia Earthquake, one of the largest
earthquakes on record (estimated 9.0 magnitude), ruptured the Cascadia Subduction
Zone offshore from Vancouver Island to northern California, and caused massive
tsunamis across the Pacific Northwest logged in Japan and oral traditions
of the Native Americans.
1755 - Lisbon, Portugal
Tens of thousands of Portuguese who survived the great
1755 Lisbon earthquake were killed by a tsunami which
followed a half hour later. Many townspeople fled to the waterfront, believing
the area safe from fires and from falling debris from aftershocks. Before
the great wall of water hit the harbour, waters retreated, revealing lost
cargo and forgotten shipwrecks.
The earthquake, tsunami, and subsequent fires killed
more than a third of Lisbon's pre-quake population of 275,000. Historical
records of explorations by Vasco da Gama and other early navigators were lost,
and countless buildings were destroyed (including most examples of Portugal's
Manueline architecture). Europeans of the 18th century struggled to understand
the disaster within religious and rational belief systems. Philosophers of
the Enlightenment, notably Voltaire, wrote about the event. The philosophical
concept of the sublime, as described by philosopher Immanuel Kant in the
Observations on the Feeling of the Beautiful and Sublime,
took inspiration in part from attempts to comprehend the enormity of the Lisbon
quake and tsunami.
1868 - Hawaiian local tsunami generated by earthquake
On April 2, 1868, a local earthquake with a magnitude
estimated between 7.25 and 7.75 rocked the southeast coast of the Big Island
of Hawaii. It triggered a landslide on the slopes of the Mauna Loa volcano,
five miles north of Pahala, killing 31 people. A tsunami then claimed 46 additional
lives. The villages of Punaluu, Ninole, Kawaa, Honuapo, and Keauhou Landing
were severely damaged. According to one account, the tsunami "rolled in over
the tops of the cocoanut trees, probably 60 feet high .... inland a distance
of a quarter of a mile in some places, taking out to sea when it returned,
houses, men, women, and almost everything movable." This was reported in
the 1988 edition of Walter C. Dudley's book, "Tsunami!" (ISBN 0-8248-1125-9).
1883 - Krakatoa explosive eruption
The island volcano of Krakatoa in Indonesia exploded
with devastating fury in 1883, blowing its underground magma chamber partly
empty so that much overlying land and seabed collapsed into it. A series of
large tsunami waves was generated from the collapse, some reaching a height
of over 40 metres above sea level. Tsunami waves were observed throughout
the Indian Ocean, the Pacific Ocean, the American West Coast, South America,
and even as far away as the English Channel. On the facing coasts of Java
and Sumatra the sea flood went many miles inland and caused such vast loss
of life that one area was never resettled but went back to the jungle and
is now the Ujung Kulon nature reserve.
The aftermath of the tsunami that struck Newfoundland in 1929.
1917 - Halifax Explosion and Tsunami
The Halifax Explosion occurred on Thursday, December
6, 1917 at 9:04:35 a.m. local time in Halifax, Nova Scotia in Canada, when
the French munitions ship Mont-Blanc, bound for World War I France, collided
with the Norwegian ship Imo chartered to carry Belgian relief supplies. In
the aftermath of the collision, Mont-Blanc caught fire and exploded. The explosion
caused a tsunami, and a pressure-wave of air.
1929 - Newfoundland tsunami
On November 18, 1929, an earthquake of magnitude 7.2
occurred beneath the Laurentian Slope on the Grand Banks. The quake was felt
throughout the Atlantic Provinces of Canada and as far west as Ottawa, Ontario
and as far south as Claymont, Delaware. The resulting tsunami measured over
7 metres in height and took about 2½ hours to reach the Burin
Peninsula on the south coast of Newfoundland, where 29 people lost their lives
in various communities.
1946 - Pacific tsunami
Hawai`i residents run from an approaching tsunami in Hilo, Hawai'i
The April 1 Aleutian Island earthquake tsunami
that killed 159 people on Hawaii and five in Alaska resulted in the creation
of a tsunami warning system (specifically The Pacific Tsunami Warning Center),
established in 1949 for Pacific Ocean area countries. The tsunami is locally
known in Hawaii as the April Fools Day Tsunami in Hawaii due to people
thinking the warnings were an April Fools prank.
1960 - Chilean tsunami
The magnitude-9.5 Great Chilean Earthquake is
the strongest earthquake ever recorded. Its epicentre, off the coast of South
Central Chile, generated one of the most destructive tsunamis of the 20th
It spread across the entire Pacific Ocean, with waves
measuring up to 25 metres high. The first tsunami arrived at Hilo, Hawaii
approximately 14.8 hrs after it originated off the coast of South Central
The highest wave at Hilo Bay was measured at around 10.7
m (35 ft.). 61 lives were lost allegedly due to people's failure to heed
warning sirens. When the tsunami hit Onagawa, Japan, almost 22 hours after
the quake, the wave height was 3 m above high tide. Up to 2,290 people died
due to the Earthquake and tsunami.
1963 - Vajont Dam disaster
The reservoir behind the Vajont Dam in northern
Italy was struck by an enormous landslide. A tsunami was triggered which swept
over the top of the dam (without bursting it) and into the valley below. Nearly
2,000 people were killed.
1964 - Good Friday tsunami
After the magnitude 9.2 Good Friday Earthquake,
tsunamis struck Alaska, British Columbia, California and coastal Pacific Northwest
towns, killing 121 people. The tsunamis were up to 6 m tall, and killed 11
people as far away as Crescent City, California.
1976 - Moro Gulf tsunami
On August 16, 1976 at 12:11 A.M., a devastating earthquake
of 7.9 hit the island of Mindanao, Philippines. It created a tsunami that
devastated more than 700 km of coastline bordering Moro Gulf in the North
Celebes Sea. An estimated number of victims for this tragedy left 5,000 dead,
2,200 missing or presumed dead, more than 9,500 injured and a total of 93,500
people were left homeless. It devastated the cities and provinces of Pagadian
City, Zamboanga del Sur, Zamboanga City, Basilan, Sulu, Sultan Kudarat, Maguindanao,
Cotabato City, Lanao del Sur and Lanao del Norte.
1979 - Tumaco tsunami
A magnitude-7.9 earthquake occurred on December 12, 1979
at 7:59:4.3 (UTC) along the Pacific coast of Colombia and Ecuador. The earthquake
and the resulting tsunami caused the destruction of at least six fishing
villages and the death of hundreds of people in the Colombian province of
Nariño. The earthquake was felt in Bogotá, Cali, Popayán,
Buenaventura and several other cities and towns in Colombia and in Guayaquil,
Esmeraldas, Quito and other parts of Ecuador. When the Tumaco Tsunami
hit the coast, it caused huge destruction in the city of Tumaco, as well as
in the small towns of El Charco, San Juan, Mosquera and Salahonda on the Pacific
Coast of Colombia. The total number of victims of this tragedy was 259 dead,
798 wounded and 95 missing or presumed dead.
1993 - Okushiri tsunami
Map of Hokkaido shown on NHK during
an emergency broadcast.
A devastating tsunami occurred off the coast of Hokkaido
in Japan as a result of a magnitude 7.8 earthquake, 80 miles offshore, on
July 12, 1993. The largest waves recorded from this event were as much as
30 metres tall. As a result, 202 people on the small island of Okushiri
were killed, and hundreds more were missing or injured. On the day of the
tsunami, an emergency bulletin from the Japan Meteorological Agency was broadcasted
on NHK. The signal was transmitted in English and Japanese, the same message
was repeated multiple times. This alert first begins with a alarm tone that
lasts about 15 seconds. This broadcast is also archived at YouTube. 
2004 - Indian Ocean tsunami
The 2004 Indian Ocean earthquake, which had a
magnitude of 9.3, triggered a series of lethal tsunamis on December 26, 2004
that killed approximately 230,000 people (including 168,000 in Indonesia
alone), making it the deadliest tsunami as well as one of the worst natural
disasters in recorded history. The tsunami killed people over an area ranging
from the immediate vicinity of the quake in Indonesia, Thailand and the north-western
coast of Malaysia to thousands of kilometres away in Bangladesh, India, Sri
Lanka, the Maldives, and even as far as Somalia, Kenya and Tanzania in eastern
Unlike in the Pacific Ocean, there was no organized alert
service covering the Indian Ocean. This was in part due to the absence of
major tsunami events since 1883 (the Krakatoa eruption, which killed 36,000
people). In light of the 2004 Indian Ocean tsunami, UNESCO and other world
bodies have called for a global tsunami monitoring system.
2006 - South of Java Island tsunami
A 7.7 magnitude earthquake shocked the Indian Ocean seabed
on July 17, 2006, 200 km south of Pangandaran, a beautiful beach famous
to surfers for its perfect waves. This earthquake triggered tsunami whose
heights varied from from 2 metres at Cilacap to 6 metres at Cimerak
beach, where it swept away and flattened buildings as far as 400 metres
away from the coastline. More than 600 people were reported killed, with
around 150 others still missing.
2006 - Kuril Islands tsunami
A 8.1-magnitude quake struck an area claimed by both
Russia and Japan, but the waves near Japan did not swell higher than 23 inches.
There were no immediate reports of casualties or damage. Six hours later,
tsunami waves up to nearly 5-foot high caused by the quake crashed into Hawaii's
shores, Crescent City, California, and Santa Cruz, California causing considerable
damage in some areas.
Other tsunamis in South Asia
|Tsunamis in South Asia
(Source: Amateur Seismic Centre, India)
||Near Dabhol, Maharashtra
|02 April 1762
||Arakan Coast, Myanmar
|16 June 1819
||Rann of Kachchh, Gujarat, India
|31 October 1847
||Great Nicobar Island, India
|31 December 1881
||Car Nicobar Island, India
|26 August 1883
||Krakatoa volcanic eruption
|28 November 1945
||Mekran coast, Balochistan
|26 December 2004
||Banda Aceh, Indonesia; Tamil Nadu, Kerala, Andhra Pradesh, Andaman
and Nicobar Islands (India); Sri Lanka; Thailand; Malaysia; Maldives; Somalia;
Other historical tsunamis
Other tsunamis that have occurred include the following:
- circa 1600BC: The Israilite crossing of the
Red (or Reed) Sea has been linked by some researchers to a tsunami following
the volcanic explosion of the Greek island of Santorini.
- circa 500 BC: Poompuhar, Tamil Nadu, India,
- circa 450 BC: The Greek historian Thucydides
in his book History of the Peloponnesian Wars, speculated about the
causes of tsunamis. He argued that it could only be explained by a consequence
of ocean earthquakes, and could see no other possible causes for the phenomenon.
- 1541: one struck the earliest European settlement
in Brazil, São Vicente. There is no record of deaths or injuries, but
the town was almost completely destroyed.
- January 20, 1606 /1607: along the coast of the Bristol
Channel (main article) thousands of people were drowned, houses and
villages swept away, farmland was inundated and flocks were destroyed by a
flood that might have been a tsunami. The cause of the flood remains disputed,
it is quite possible that it was caused by a combination of meteorological
extremes and tidal peaks.(discussion).
- One of the worst tsunami disasters engulfed whole
villages along Sanriku, Japan, in 1896. A wave more than seven stories tall
(about 20 m) drowned some 26,000 people.
- July 9, 1958: A huge landslip caused a tsunami in
the fjord shaped Lituya Bay, Alaska, USA. It travelled at over 150 km/h.
It was the worlds tallest recorded tsunami at 524 m (1719 ft).
- May 26, 1983: 104 people in western Japan were killed
by a tsunami spawned from a nearby earthquake.
- 17 July 1998: A Papua New Guinea tsunami killed
approximately 2200 people . A 7.1 magnitude earthquake 24 km offshore
was followed within 11 minutes by a tsunami about 12 m tall. While the magnitude
of the quake was not large enough to create these waves directly, it is believed
the earthquake generated an undersea landslide, which in turn caused the
tsunami. The villages of Arop and Warapu were destroyed.
- 17 July 2006: A six-foot high tsunami hit the south
coast of the island of Java, Indonesia at approximately 11:20 UTC. It killed
at least 668 people and damaged houses, boats and hotels on or near Pangandaran
beach. The tsunami was the direct result of a 7.7 magnitude earthquake offshore
in the Indian Ocean. See July 2006 Java earthquake.
North American and Caribbean tsunamis
- 1690 - Nevis
- 14 November 1840 - Great Swell on the Delaware River
- 18 November 1867 - Virgin Islands
- 17 November 1872 - Maine
- 11 October 1918 - Puerto Rico
- 18 November 1929 - Newfoundland
- 9 January 1926 - Maine
- 4 August 1946 - Dominican Republic
- 18 August 1946 - Dominican Republic
- 35 million years ago - Chesapeake Bay impact crater,
- 9 June 1913 - Longport, NJ
- 6 August 1923 - Rockaway Park, Queens, NY .
- 8 August 1924 - Coney Island, NY .
- 19 August 1931 - Atlantic City, NJ
- 21 September 1938 - Hurricane, NJ coast.
- 19 May 1964 - Northeast USA
- 4 July 1992 - Daytona Beach, FL
Source: NOAA National Weather Service Forecast Office
- 6100 BC - Storegga Slide, Norway
- 16 October 1979 - 23 people died when the coast
of Nice, France, was hit by a tsunami. This may have had a manmade cause
due to construction at the new Nice airport creating an undersea landslide.