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 lives.

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’ means wave.

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

ITIC:
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 Organization (UNESCO).
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.

Damages: 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 away.

Help the Victims: