7. A tsunami (plural: tsunamis or tsunami; from Japanese: 津波, lit. "harbour
wave";[1] English pronunciation: /suːˈnɑːmi/ soo-NAH-mee or /tsuːˈnɑːmi/ tsoo-
NAH-mee[2]) is a series of water waves caused by the displacement of a large
volume of a body of water, generally an ocean or a large
lake. Earthquakes, volcanic eruptions and other underwater
explosions (including detonations of underwater nuclear devices),
landslides, glacier calvings, meteorite impacts and other disturbances above or
below water all have the potential to generate a tsunami.[3]
Tsunami waves do not resemble normal sea waves, because their wavelength is
far longer. Rather than appearing as a breaking wave, a tsunami may instead
initially resemble a rapidly rising tide, and for this reason they are often
referred to astidal waves. Tsunamis generally consist of a series of waves
with periods ranging from minutes to hours, arriving in a so-called "wave
train".[4] Wave heights of tens of metres can be generated by large events.
Although the impact of tsunamis is limited to coastal areas, their destructive
power can be enormous and they can affect entire ocean basins; the 2004 Indian
Ocean tsunami was among the deadliest natural disasters in human history
with at least 290,000 people killed or missing in 14 countries bordering
the Indian Ocean.
14. TSUNAMI IN ANDAMAN & NICOBAR
A severe earthquake measuring 8.9 Richter scale, was felt in Andaman and Nicobar
Islands having epicentre at 3.7N and 95E off the island of Sumatra between 0630 to 0635
hours in the morning of 26th December, 2004. The quake was followed the "Killer
Waves" or Tsunami which caused extensive damages to life & property in this
archipelago.
But we would like to draw the attention of all about the true picture of the effect/damage.
The maximum damage has been in the Nicobar group of Islands and NOT in the
Andaman group of islands. If you look at the map of the Andaman & Nicobar Islands ,
you will find that Andaman & Nicobar are two completely different group of islands.
The entire Andaman group of islands (excepting Little Andamans) have been literally
spared from the devastating Tsunami. Most importantly there has been no injuries or
deaths amongst tourists - since tourists are anyway not allowed to visit the Nicobar group
of islands.
Things are now fast coming back to normal here. Since, there has been no big damage in
any of the major/popular tourist spots/destinations (like Port Blair, Havelock, Neil island,
etc.) - Indian Airlines & Jet Airways have restarted their daily scheduled flights from
Kolkata (Calcutta) & Chennai (Madras) and tourists are now allowed to come here once
again.
There was a temporary prohibition (just as a precautionary measure) on scuba diving for
sometime - which has also now been removed. So, tourists can now once again go for
diving, snorkeling, game fishing, etc.
16. TSUNAMI IN
PORT BLAIR (THAI LAND)
Tsunamis are large waves of water usually triggered by an earthquake,
explosion or other event displacing a large amount of water. Out in the open
ocean, tsunamis are typically harmless and unnoticeable to the naked eye.
When they start, tsunami waves are small and wide -- the height of the waves
can be as small as a foot, and they can be hundreds of miles long and move
very quickly, so they can pass practically unnoticed until the get to shallow
water closer to land. But as the distance between the bottom of the ocean floor
and the water gets smaller, these short, wide, fast waves compress into
extremely high, powerful waves that wash onto land. Depending on the
amount of energy involved, they can reach more than 100 feet in height.
Read more about tsunamis.
The 2004 Tsunami, referred to as the 2004 Indian Ocean Tsunami, the 2004
Indonesian Tsunami or the 2004 Boxing Day Tsunami, was one of the worst
natural disasters in recorded history. It was triggered by an undersea
earthquake with an estimated magnitude of between 9.1 to 9.3, making it the
third most powerful quake ever recorded.
The tsunami that the massive earthquake generated killed more than 230,000
people in Indonesia, Sri Lanka, India and Thailand, displaced hundreds of
thousands of people and caused billions of dollars in property damage.
22. Tilly Smith (born 1994) is a British woman who, as a girl aged 10,
was credited with saving nearly a hundred foreign tourists at
Maikhao Beach in Thailand by warning beachgoers minutes before
the arrival of the tsunami caused by the 2004 Indian Ocean
earthquake.
Tilly Smith learned about tsunamis in a geography lesson two
weeks before the tsunami from her teacher Andrew Kearney
at Danes Hill School in Oxshott, Surrey. She recognised the
symptoms of receding water from the shoreline and frothing
bubbles on the surface of the sea and alerted her parents, who
warned others on the beach and the staff at the hotel
on Phuket where they were staying. The beach was evacuated
before the tsunami reached shore, and was one of the few beaches
on the island with no reported casualties.
At Danes Hill Preparatory School a cameraman was allowed to
follow Smith around for a day to find out what she normally did at
30. TSUNAMI IN GALLE
The country of Sri Lanka (formerly Ceylon), located 31 miles off the south-eastern coast of
India, was hit by a tsunami triggered by a 9.0 magnitude earthquake off the coast of Sumatra
on December 26, 2004. The tsunami was one of the worst disasters ever recorded in Sri
Lankan history. The tsunami left tens of thousands dead, many more homeless, and caused
widespread chaos throughout the island. In addition to the human impacts, the tsunami had
widespread effects on Sri Lanka's environment and ecosystems. It is still too early to express
the long-term effects caused by the tsunami, but short-term effects are clearly evident.
Human Impacts
Civilian casualties in Sri Lanka were second only to those in Indonesia (see Indonesia).
Reports vary on the number of deaths since many people are still missing and the country
lacks adequate communications. As of March 1, 2005, estimates state that 36,603 people
perished in the months following the tsunami. Another 800,000 people living on the coasts
of Sri Lanka have been directly affected. The eastern shores of Sri Lanka faced the hardest
impact since they were facing the epicenter of the earthquake. The southwestern shores were
hit later, but the death toll was just as severe.
The coastal lifestyle of people in Sri Lanka contributed to the high death tolls. The following
images illustrate the correlation between population, affected areas, and mortality rates. In
addition to the high number of fatalities, approximately 90,000 buildings were destroyed.
Houses were easily destroyed since they were built mostly from wood. This wooden debris
that was left behind is now raising issues of its own
31.
32.
33.
34. The term tsunami has its origins in the Japanese language; an English equivalent is "seismic sea
waves." Tsunamis are often incorrectly interchanged with the term" tidal waves," which refer to
high waves of water caused by changes in the flow and surge of the ocean. Tsunamis, on the other
hand, can be caused by a few different means: 1) the down drop or upthurst of the Earth’s crust
which results in an earthquake; 2) a large-scale undersea landslide; 3) a submarine volcanic
eruption of a certain degree; or potentially, 4) a large meteor impact at sea. The vast majority of
tsunamis result from earthquakes.
(Source: The Great Waves).
a
How Earthquakes Cause Tsunamis
The illustration below shows a subduction earthquake (one where a denser plates shifts below its
neighboring plate, at left). Energy is transferred and the displaced water forms a wave. As the
wave travels and enters shallower water in the coastal area, it begins to increase in amplitude
(National Geographic).
Killer Wave! Tsuanmi--National Geographic Kids
Tsunamis are not always colossal waves when they come into the shore. In fact, "... most
tsunamis do not result in giant breaking waves (like normal surf waves at the beach that curl over
as they approach shore). Rather, they come in much like very strong and very fast tides (i.e., a
rapid, local rise in sea level)." (USGS website) Nevertheless, there is destruction of life and of
property by floating debris and impact of water. The tsunami produces a series of rushing waves
and also a series of withdrawals.
