DESCRIBE THE EFFECTS OF SOME OF THE NATURAL HAZARDS THAT OCCUR AS A RESULT OF THE EARTH'S INTERNAL FORCES.

Earthquakes, volcanoes, and tsunamis are all natural hazards caused by the movement of plates on the surface of the earth. Natural hazards are natural events that threaten people and their activities. As you have learned, earthquakes are caused by movement of continental plates, and volcanoes are caused as molten magma makes its way to the earth's surface. What about tsunamis like the one you read about at the beginning of the lesson? What causes them?

Tsunamis

The National Oceanic and Atmospheric Administration (NOAA) has defined tsunamis as follows:

“Tsunamis are a series of very long waves generated by any rapid, large-scale disturbance of the sea. Most are generated by seafloor displacements from large undersea earthquakes; [however, tsunamis can also be caused by volcanic eruptions, oceanic landslides, or any other event that displaces a large amount of water.] Tsunamis can cause great destruction and loss of life within minutes on shores near their source, and some tsunamis can cause destruction within hours across an entire ocean basin.

Most tsunamis occur in the Pacific region, but they [have been] known to happen in every ocean and sea. Although infrequent, tsunamis are a significant natural hazard with great destructive potential. They can only be dealt with effectively through programs of warning, mitigation, and education.”¹

Footnotes

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