Tsunami and Survival
The fifth-largest earthquake in a century
with magnitude of 8.9 Richter scale, struck the coast of the northern
Indonesia Island of Sumatra early on 26th Dec 2004,triggering tsunamis that
crashed into Srilanka and India, drowning thousands and swamping tourist
isles in Thailand and the Maldives.
What is tsunami?
||Tsunami is a
wave train or series of waves generated, by impulsive disturbance that
vertically displaces the water column, in water body. Earthquake,
landslides, volcanic eruption, explosion and even the impact of cosmic
bodies like meteorites commonly generate tsunami. Tsunami savagely
attacks coastlines causing devastating property damage and loss of
What tsunami does mean?
Tsunami is a Japanese word meaning ‘harbor wave’. It is constituted
with two syllables, one – ‘TSU’ means harbor and the other one is ‘NAMI’
How do tsunami differ from other water waves?
Tsunamis are unlike the wind-generated waves on local lakes or coastal
beaches, in that they are characterized as shallow-water waves, with long
periods and wavelengths. The wind-generated swell like the one at a
California beach spawned by a storm out in the pacific and rhythmically
rolling in, one wave after another might have a period of about 10 seconds
and a wavelength of 150 m. A tsunami, on the other hand, can have a
wavelength in excess of 100 km and period on the order of one hour. As a
result of their long wave lengths tsunami behave as shallow-water waves. A
wave becomes a shallow water wave when the ratio between the water depth
and its wave length gets very small. 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/s) and the water depth. This means, in the Pacific Ocean,
where the typical water depth is about 4000m, a tsunami travels at about
200m/s, or over 700 700km/hr. Because the rate at which a wave losses its
energy is inversely related to its wavelength, tsunami not only propagate
at high speeds, they can also travel great, transoceanic distances with
limited energy losses. The wave crests bend as the tsunami travels—is
called refraction. Wave refraction is caused by segments of the wave moving
at different speeds as the water depth along the crest varies.
How does earthquake generate tsunami?
Tsunami can be generated when the see floor abruptly deforms and vertically
displaces the overlying water. Tectonic earthquakes are a particular kind
of earthquake that are associated with the earth’s crustal deformation,
when these earthquakes occur beneath the see, the water above the deformed
area is displayed from its equilibrium position. Waves are formed as the
displaced water mass, which acts under the influence of gravity, attempts
to regain its equilibrium.
Tsunami safety Rules:
An earthquake in an area is a natural tsunami warning. Do not stay in
low-lying coastal areas after a strong earthquake has been felt.
A tsunami is not a single wave, but a series of waves. Stay out of danger
areas until competent authority issues an “all-clear”.
All tsunamis like hurricanes are potentially dangerous; even though they
may not damage every coastline they strike.
Never go down to the shore to watch for a tsunami. When see the wave you
are too close to escape it. Never try to surf a tsunami; tsunamis do not
curl or break like surfing waves.
Sooner or later, tsunamis visit every coastline in the Pacific. Warnings
apply to you if you live in any Pacific coastal area.
Tsunami warning Organization
The International Tsunami Information Center (ITIC) was established in
Honolulu, in November 1965, by the Intergovernmental Oceanographic
Commission (IOC) of the United Nations Educational, Scientific and Cultural
In 1968, IOC formed an International Coordination Group for the Tsunami
Warning System in the Pacific (ICG/ITSU).
The present Member States are:
Australia, Canada, Chile, China, Colombia, Cook Islands, Costa Rica,
Democratic People’s Republic of Korea, Ecuador, El Salvador, Fiji, France,
Guatemala, Indonesia, Japan, Mexico, New Zealand, Nicaragua, Peru, Republic
of the Philippines, Republic of Korea, Russian Federation, Samoa,
Singapore, Thailand, and the United States of America.
The International Tsunami Warning System in the Pacific is one of the most
successful international scientific programs with the direct humanitarian
aim of mitigating the effects of tsunami by saving lives and property.
Loss or harm caused by a destructive tsunami. More specifically, the
damage caused directly by tsunamis can be summarized into the
following: 1) deaths and injuries; 2) houses destroyed, partly
destroyed, inundated, flooded, or burned; 3) other property damage and
loss; 4) boats washed away, damaged or destroyed; 5) lumber washed
Help the Victims: