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Tsunami

2007 Schools Wikipedia Selection. Related subjects: Natural Disasters

   The tsunami that struck Malé in the Maldives on December 26, 2004.
   Enlarge
   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.

Causes

   Generation of a tsunami
   Enlarge
   Generation of a tsunami

   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.

Characteristics

   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.
   Enlarge
   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 subsides.

   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/s^2) 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 mi/h) 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 mi/h), 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 surrounding geography.

   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.

Tsunami wave

   Ocean waves are normally divided into 3 groups, characterized by depth:
     * 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 a helicopter,
          + 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

         "Tsunami Hazard Zone" sign at the University of California, Santa
                                                                   Barbara
                                                                   Enlarge
         "Tsunami Hazard Zone" sign at the University of California, Santa
                                                                   Barbara

                                            Tsunami wall at Tsu-shi, Japan
                                                                   Enlarge
                                            Tsunami wall at Tsu-shi, Japan

   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.
   Enlarge
   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 artificial
   barriers.

Historical tsunamis

   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 Indian Ocean.

   ^

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.
   Enlarge
   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
   Enlarge
   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 Centre),
   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 century.

   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 Chile.

   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

   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 Africa.

   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)
   Date Location
   1524 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; Kenya; Tanzania

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, Maldives
     * 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

   Possible tsunamis
     * 35 million years ago - Chesapeake Bay impact crater, Chesapeake Bay
     * 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

European tsunamis

     * 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.

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