Tsunami: The Wave of Disaster

by Candice Fast

At approximately 9:30 a.m. Sunday, December 26, 2004, large waves pounded the many beaches of East Asian countries killing thousands in its reach. Many have since paused to listen or read facts on this massive natural disaster and wonder if something so devastating could once again reap its fury on the earth.

This leads us to the question of what is a tsunami and how does it form? Arthur Getis, Judith Getis, and Jerome D. Fellmann write a detailed description of a tsunami in their book Introduction to Geography, Ninth Edition. They define a tsunami as being large seismic waves created by ocean floor volcanic eruptions or earthquakes. The authors describe the occurance in three steps:

Crustal movements on the ocean floor causes blocks of the seafloor to drop, causing a depression on the seafloor.
Water quickly rushes to fill the depression and this creates a upward bouncing of water towards the surface of the sea. Tremendous power is created through the momentum and rythum that occurs.
The power of the movement creates swells in the water and the swells become waves once the water reaches shallow seafloor depths.

The water can move very quickly and in the case of the most recent tsunami, water speed reached 800kph. With such fast moving water, it is no wonder the waves caused the destruction they did.

Another question is whether or not a large scale tsunami has ever occurred before. The answer is yes but not in such grand measures. According to the authors, tsunamis have hit four other regions since these natural disasters have been first recorded: Japan (June 1896), Hawaii (April 1946), Chile (May 1960), and Papua New Guinea (July 1998). The most devastating was the Japan tsunami that ended in approximately 27,000 deaths.

Following the Hawaii tsunami in 1946, Pacific coastal communities and the United States Coast and Geodetic Survey established the Tsunami Early Warning System in 1948. Major earthquakes that have potential to create a tsunami are reported to the Tsunami Warning Center in Honolulu, Hawaii. If a tsunami is detected, low-lying communities are immediately given information about its source, speed, and estimated time of arrival.

World leaders are hoping to put such centers in those places that were hit by the recent tsunami but many are concerned that it may be hard to contact small villages in remote locations with emergencies and urgent information (information obtained from television news show, Canada AM). With the warning systems, tsunamis and other oceanic disasters are easier to detect and will hopefully prevent a replay of the recent devastation.

Click here for a satellite map of the regions affected by the East Asian tsunami.

Unless otherwise noted, the above information was collected and summarized from the book, Introduction to Geography, Ninth Edition, authored by Arthur Getis, Judith Getis, and Jerome D. Fellmann. The information was published by McGraw-Hill, a business unit of McGraw-Hill Companies, Inc.

Images courtesy of CyberJournalist.net.

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