What do tsunamis happen

The coastline of the continents was changed drastically and almost all life on land was exterminated. Tsunami pronounced soo-NAH-mee is a Japanese word. Tsunamis are fairly common in Japan, and many thousands of Japanese have been killed by them in recent centuries. An earthquake generates a tsunami if it is of sufficient force and there is violent movement of the earth to cause substantial and sudden displacement of a massive amount of water.

A tsunami is not a single wave but a series of waves, also known as a wave train. The first wave in a tsunami is not necessarily the most destructive. Tsunamis are not tidal waves. Tsunami waves can be very long as much as 60 miles, or kilometers and be as far as one hour apart. They are able to cross entire oceans without great loss of energy.

The Indian Ocean tsunami traveled as much as 3, miles nearly 5, kilometers to Africa, arriving with sufficient force to kill people and destroy property. Scientists say that a great earthquake of magnitude 9 struck the Pacific Northwest in and created a tsunami that caused flooding and damage on the Pacific coast of Japan.

The largest run-up measured as elevation about sea level was recorded as 7. The largest reported offshore wave height was six metres near Cape Leveque from the August Sunda tsunami. Dominey-Howes D. Marine Geology doi Goff, J. Progress in Physical Geography 38 2 : DOI: Geoscience Australia is committed to support Australia's capability to manage the impact of natural hazards, including tsunami.

Geoscience Australia:. Geoscience Australia receives real-time data from over 60 seismic stations in Australia and more than international seismic stations. The seismic information is automatically analysed by Geoscience Australia's seismic monitoring and analysis systems that form part of the 24 hours a day, seven days a week operations centre.

When an earthquake occurs, this system automatically computes preliminary information on the earthquake's origin time time at which the earthquake happened , location, depth and magnitude. The Duty Seismologist assesses this information and then calculates a moment magnitude, Mwp, similar to a Richter magnitude to assist in determining the potential for the earthquake to cause a tsunami.

If Duty Seismologist considers that the earthquake has the potential to generate a tsunami that may impact Australia, the seismologist sends the information to the JATWC office in the Bureau of Meteorology in Melbourne via a dedicated data link. This process is completed within 10 minutes of the earthquake's origin time. These instruments provide real-time sea level observations that can verify whether an earthquake has generated a tsunami and, if so, monitor its path.

The data are provided by coastal sea level stations and deep ocean tsunami detection sensors. Equipped with these sea level data and the Bureau of Meteorology's tsunami modeling, specially trained JATWC staff then issue a warning that is in keeping with the determined threat level. These warnings identify affected coastal regions, initial tsunami arrival times and whether the tsunami threat is to land or marine areas.

Official Tsunami Bulletins General Information. Tsunami Bulletins. Tsunami Exercises General Information. Types of Exercise. How to Conduct Tsunami Exercise. Tsunami Exercises in Country. Tsunami Events Global List. Tsunamis in Indian Ocean. Tsunamis in Indian Ocean Countries. International Tsunami Survey Team. Member States. Regional Tsunami Service Providers.

Working Group 3: Tsunami Awareness and Response. Resources Awareness and Education Materials Booklet. List of Training Offers. They move relative to each other at rates of up to several inches per year. A plate boundary is the area where two plates come into contact. The way one plate moves relative to another determines the type of boundary: spreading, where the two plates move away from each other; subduction, where the two plates move toward each other, with one sliding beneath the other; and transform, where the two plates slide horizontally past each other.

Subduction is the main cause of major tsunami events. There are subduction zones with associated deep-sea trenches off Chile, Alaska, Japan, and Indonesia, for example, that have produced large earthquakes and devastating tsunamis, many of which caused damage and loss of life in the Hawaiian Islands. Part of the seafloor snaps upward as the tension is released.