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31-Tsunami etc

There are three phenomena related to water, sea, or ocean, these are Tsunami, Hurricane and Tornado
Some are related to land, such as Twisters

Tsunami is is series of water waves, from minutes to hours, caused by the displacement of large body of volume of water, typically from an ocean or a very large lake. Earthquakes, volcanic eruptions and other underwater eruptions, landslides, meteorites etc and other disturbance inside or above the water have the potential to generate a Tsunami. Tsunami waves are not like sea waves, because their wave length is far longer than the ordinary waves length. It initially resembles a rapidly rising high tide (for this reason sometimes they are referred to as tidal waves). Wave heights can be tens of meters.

The 2004 Indian Ocean Tsunami was among the deadliest natural disasters in human history with over 230,000 people killed in 14 countries bordering the Indian Ocean.

(1) A hurricane is a tropical cyclone, occurring in the North Atlantic Ocean, or the North-east Pacific Ocean - east of the International Dateline. Tropical Cyclone is characterized by low pressure center and numerous thunderstorms, that produce high winds and heave rain. These cyclones get strengthened when water evaporated from the ocean is released as the saturated air rises.

Tropical refers to the geographical regions, and the term cyclone refers to such storms of cyclonic nature, with counterclockwise wind in the Northern Hemisphere, and clockwise in Southern Hemisphere - this opposite movement of the wind is because of "Coriolis Force". Depending upon the location and strength, a tropical cyclone is referred to by names such as hurricane, typhoon, tropical storm, tropical depression, cyclonic storm, or simply cyclone.

While tropical cyclones can produce extremely powerful winds and torrential rain, they are also able to produce high waves, damaging storm surge, and tornadoes. They develop over large bodies of warm water, and lose their strength if they move over land due to increased surface friction and loss of the warm ocean as an energy source. This is why coastal regions can receive significant damage from a tropical cyclone, while inland regions are relatively safe from receiving strong winds. Heavy rains, however, can produce significant flooding inland, and storm surges can produce extensive coastal flooding up to 40 kms (25 mi) from the coastline. Although their effects on human populations can be devastating, tropical cyclones can relieve drought conditions.

(2) A wind of Force 12 on the Beaufort, above 118 km / ph is also called a Hurricane, irrespective of the origin or location.


A hurricane in the North-Pacific Ocean is called typhoon.

Twister appears on land. It is circular wind rising above as a funnel. Whatever comes in that funnel goes up because of funnel effect.

October 29, 2012 - Sandy Hurricane
1969                     - Camille
1985                     - Gloria
1992                     - Andrew
1999                     - Floyd
2005                    - Katrina




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Created by Sushma Gupta on January 15, 2002
Modified on 02/28/14