Tsunami strike
without warning. The resulting damage can be minimized and lives can be saved
if the people living near the coastal areas are already prepared survive the
strike .This requires a warning system. The warning signal can be transmitted
to different places using satellite communication network, fiber -optics
network, cell phone service or a combination of these. For sea side areas, an
alert system using Global System for Mobile communication (GSM) network is
proposed. This system does not try to find the origin of tsunami waves but it
simply generates an alert signal when the pressure level of sea water crosses a
threshold.
Tsunami is a natural
disaster. It cannot be avoided.But we can reduce the damages caused by it. For
that we are in need of tsunami warning system. The system used here is
Deep-ocean Assessment and Reporting of Tsunami(DART).We are also going to see
how the global system for mobile communications(GSM)network reduces the time
taken to warn people.
A tsunami is a series
of water waves caused by the displacement of a large volume of a body of water,
such as an ocean. Due to the immense volumes of water and energy involved,
tsunamis can devastate coastal regions. A tsunami can be generated when
convergent or destructive plate boundaries abruptly move and vertically
displace the overlying water. Subduction zone related earthquakes generate the
majority of tsunami. Tsunamis have a small amplitude (wave height) offshore,
and a very long wavelength (often hundreds of kilometers long), which is why
they generally pass unnoticed at sea, forming only a slight swell usually about
300 millimeters (12 in) above the normal sea surface. They grow in height when
they reach shallower water, in a wave shoaling process described below.
A tsunami can occur
in any tidal state and even at low tide can still inundate coastal areas.
Tsunamis in deep water can have a wavelength greater than 300 miles (482
kilometers) and a period of about an hour. When the ocean is 20,000 feet deep,
a tsunami travels at 550 miles per hour. At this speed, the wave can compete
with a jet airplane, traveling across the ocean in less than a day. Because a
wave loses energy at a rate inversely related to its wavelength, tsunamis can
travel at high speeds for a long period of time and lose very little energy in
the process. In extreme cases, the water level can rise to more than 50 feet
above sea level for tsunamis of distant origin, and over 100 feet for tsunamis
generated nearby. An earthquake may generate a tsunami if the quake occurs just
below a body of water, is of moderate or high magnitude and displaces a
largeenough volume of water.
0 comments: