Signs Of An Approaching Tsunami
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tsunami, tsunami photos, tsunami pictures, tsunami videos, tusunami
There is often no advance warning of an approaching tsunami. However, since earthquakes are often a cause of tsunami, any earthquake occurring near a body of water may generate a tsunami if it occurs at shallow depth, is of moderate or high magnitude, and the water volume and depth is sufficient. In Japan moderate - 4.2 Magnitude earthquakes can generate tsunami which can inundate the area within 15 minutes.
If the first part of a tsunami to reach land is a trough (draw back) rather than a crest of the wave, the water along the shoreline may recede dramatically, exposing areas that are normally always submerged. This can serve as an advance warning of the approaching tsunami which will rush in faster than it is possible to run. If a person is in a coastal area where the sea suddenly draws back (many survivors report an accompanying sucking sound), their only real chance of survival is to run for high ground or seek the high floors of high rise buildings.
In the 2004 tsunami that occurred in the Indian Ocean drawback was not reported on the African coast or any other western coasts it inundated, when the tsunami approached from the east. This was because of the nature of the wave - it moved downwards on the eastern side of the fault line and upwards on the western side. It was the western pulse that inundated coastal areas of Africa and other western areas.
80% of all tsunamis occur in the Pacific Ocean, but are possible wherever large bodies of water are found, including inland lakes. They may be caused by landslides, volcanic explosions, bolides and seismic activity.
Tsunami
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tsunami, tsunami photos, tsunami pictures, tsunami videos, tusunami
A tsunami is a series of waves created when a body of water, such as an ocean, is rapidly displaced. Earthquakes, mass movements above or below water, some volcanic eruptions and other underwater explosions, landslides, underwater earthquakes, large asteroid impacts and testing with nuclear weapons at sea all have the potential to generate a tsunami. The effects of a tsunami can be devastating due to the immense volumes of water and energy involved. Since meteorites are small, they will not generate a tsunami.
The Greek historian Thucydides was the first to relate tsunamis to submarine quakes, but understanding of the nature of tsunamis remained slim until the 20th century and is the subject of ongoing research.
Many early geological, geographic, oceanographic etc; texts refer to "Seismic sea waves" - these are now referred to as "tsunami."
Some meteorological storm conditions - deep depressions causing cyclones, hurricanes; can generate a storm surge which can be several metres above normal tide levels. This is due to the low atmospheric pressure within the centre of the depression. As these storm surges come ashore the surge can resemble a tsunami, inundating vast areas of land. These are not tsunami. Such a storm surge inundated Burma (Myanmar) in May 2008.
Indonesia Tsunamis 1883
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tsunami, tsunami history, tsunami photos, tsunami pictures, tsunami videos, tusunami
The
volcanic explosion of Krakatoa is one of the most impressive natural
disasters ever recorded in history. On August 26th 1883, the island
volcano of Krakatoa exploded with devastating fury, blowing its
underground magma chamber partly empty so that much overlying land and
seabed collapsed into it. The great majority of the island simply was
destroyed as it sank to the ocean floor. The volcanic disturbance
triggered a series of large tsunami waves, some reaching a height of
over 40 meters above sea level. Although no one is known to have been
killed as a result of the initial explosion, the tsunamis it generated
had disastrous results, killing over 36,000 people, and wiping out a
number of settlements, including Telok Batong in Sumatra, and Sirik and
Semarang in Java.
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. Ships as far away as South Africa rocked
as tsunamis hit them, and the bodies of victims were found floating in
the ocean for weeks after the event. There are even numerous documented
reports of groups of human skeletons floating across the Indian Ocean
on rafts of volcanic pumice and washing up on the east coast of Africa
up to a year after the eruption.
Portugal and Much of Europe Tsunamis 1755
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tsunami, tsunami history, tsunami photos, tsunami pictures, tsunami videos, tusunami
On
November 1st 1755, one of the biggest earthquakes in history occurred
in the Atlantic Ocean just of the coast of the Portuguese capital city
of Lisbon. The total duration of shaking lasted ten minutes and was
comprised of three distinct jolts. Scientists estimate that the
earthquake was in the range of 9.0 on the Richter scale, which caused
extensive damage throughout Lisbon. Surprisingly, the events that
unfolded from this disaster has been well-documented.
After the earthquake, survivors rushed to the open space of the
docks for safety and watched as the water receded, revealing the sea
floor, littered by lost cargo and old shipwrecks. About 35 minutes
after the initial earthquake, an enormous tsunami engulfed the
Portuguese harbor and the city’s downtown. Two other tsunamis followed
to add to more devastation to the already suffering area. Effects from
the earthquake and tsunamis were far reaching. The worst damage
occurred in the south-west of Portugal, which included Lisbon. The
tsunami reached, with less intensity, the coast of Spain, France, Great
Britain, Ireland, Belgium and Holland. In Madeira and in the Azores
islands damage was extensive and many ships were in danger of being
wrecked. In total, over 100,000 people were killed, with most
fatalities incurred in Lisbon, where over a third of the population
were instantaneously wiped out. This tragic disaster served as the
impetus for earthquake research in the world.
Japan Tsunamis 1896
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tsunami, tsunami history, tsunami photos, tsunami pictures, tsunami videos, tusunami
On
June 15 1896, an earthquake occurred of the coast near the Japanese
port city of Sanriku. The earthquake, which measured 7.2 on the
Richter scale, triggered the formation a massive tsunami that
devastated the city killing over 26,000 people. The tsunami waves
reached an intimidating height of 25 meters (80 feet) as it crashed
upon a crowd that had gathered in a city to celebrate a religious
festival. The tsunami was also observed across the Pacific: In Hawaii,
wharves were demolished and several houses were swept away. In
California, a 9.5 feet wave was observed, according to the San
Francisco Chronicle of June 16, 1896. This Sanriku tsunami served as
an impetus for tsunami research in Japan.
What is unusual about this disaster is that the size of the tsunami
was much larger than would be expected from the size of the earthquake,
7.2 on the Richter scale. At the time of the Sanriku tsunami
earthquake, a weak shock was felt, followed by an extremely slow
shaking that lasted about 5 minutes. Approximately 35 minutes after the
earthquake, the large tsunami arrived at the Sanriku coast.
Chile and Pacific Nations Tsunamis 1960
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tsunami, tsunami history, tsunami photos, tsunami pictures, tsunami videos, tusunami
On
May 22 1960, the biggest earthquake ever recorded at the time occurred
just of the coast of South central Chile, a nation of South America.
The earthquake measured 9.5 on the Richter scale with swarms of
aftershock earthquakes that measured as large 8.0 that followed. The
earthquakes triggered the creation of tsunami, which was responsible
for most of the ensuing devastation and death.
The tsunami, together with the coastal subsidence and flooding,
caused tremendous damage along the Chile coast, where about 2,000
people died. The waves spread outwards across the Pacific. Fifteen
hours after the earthquake, tsunami waves flooded Hilo, on the island
of Hawaii, where they built up to thirty feet and caused 61 deaths
along the waterfront. Seven hours after that the waves flooded the
coastline of Japan where ten-foot waves caused 200 deaths. Tsunami
waves also caused damage in the Marquesas, in Samoa, and in New
Zealand.
West Coast of North America Tsunamis 1964
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tsunami, tsunami history, tsunami photos, tsunami pictures, tsunami videos, tusunami
Now
known as the Good Friday Tsunami, the west coast, especially in the
state of Alaska, was affected by a tsunami that was the most
devastating ever in the continent of North America. On March 28th
1964, the United States experienced its biggest earthquake in history
near College Fjord in Prince William Sound of the coast of Alaska that
measured 9.2 on the Richter scale. The earthquake lasted for three to
five minutes in most areas with jolting of the ocean floor creating
large tsunamis. Although the earthquake did cause some destruction,
the majority of death and property damage was caused by the resulting
tsunami. The small Alaskan coastal communities of Girdwood, Portage,
Vladez, and some native villages were absolutely decimated. There were
a total of 106 people killed in Alaska due to the tsunami waves which
reached heights of 11.5 meters (38 feet).
The tsunami traveled south along the west coast to impact the
Canadian province of British Columbia. The mainland coast and
Vancouver Island were affected where houses were seen being washed away
to sea. Considerable damage was also felt in Crescent City, California
where eleven people lost their lives. Even Hawaii, thousands of
kilometers away felt the impact of the tsunami.
Philippines Tsunamis 1976
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tsunami, tsunami history, tsunami photos, tsunami pictures, tsunami videos, tusunami
Around midnight on August 16th 1976, an earthquake measuring approximately 7.6 on the Richter scale occurred in the Moro Gulf a few miles away from the coast of the Philippine island of Mindanao. The earthquake itself was responsible for causing widespread damage, but its effect paled in comparison to the tsunami it helped created. The massive tsunami that devastated 700 kilometers of coastline bordering Moro Gulf in the North Celebes Sea, resulting in destruction and death in the coastal communities of the Sulu Archipelago and southern Mindanoa, including Zamboanga City and Pagadian City. Over 5,000 people were killed as they were swept out to sea, with thousands more remaining “missing”.
Papua New Guinea Tsunamis 1998
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tsunami, tsunami history, tsunami photos, tsunami pictures, tsunami videos, tusunami
On July 17th, 1998, an earthquake measuring 7.1 on the Richter scale occurred about 15 miles just of the coast of northern Papua New Guinea, an island nation located in the southwestern Pacific Ocean just south of Indonesia and north of Australia. While the magnitude of the quake was not large enough to create the tsunami directly, it is believed the earthquake generated an undersea landslide, which in turn caused the tsunami. Following the earthquake, a tsunami with waves reaching 12 meters (40 feet) hit the Papua New Guinea coast within 10 minutes, destroying the villages of Arop and Warapu. An estimated 2,200 people were killed.
Indian Ocean Tsunamis 2004
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tsunami, tsunami history, tsunami photos, tsunami pictures, tsunami videos, tusunami
A
massive earthquake measuring over 9.0 on the Richter scale occurred
under the Indian ocean floor just of the coast of the Indonesian island
of Sumatra. Violent movement of the Earth's tectonic plates in this
area displaced an enormous amount of water, sending powerful tsunami
waves in every direction. Within hours killer tsunami waves radiating
from the earthquake’s epicenter slammed into the coastline of 12 Indian
Ocean countries. The tsunami waves had heights reaching up to 15
meters (50 feet) which snatched people out to sea, drowning others in
their homes or on beaches, and demolishing an immense amount of
property in many areas.
The tsunamis generated by the earthquake have killed over the
150,000 people in twelve countries (Indonesia, India, Sri Lanka,
Thailand, Malaysia, Maldives, Myanmar, Bangladesh, the Andaman and
Nicobar Islands, the Maldives, Seychelles, Somalia, Tanzania, and
Kenya). The hardest hit country was Indonesia, which was the closest
to the earthquake’s epicenter. The country have reported death tolls
exceeding over 105,000 people with almost all mortalities from the Aceh
Province at the northern end of the island of Sumatra.
