Daily Almanac for
Nov 12, 2009
Search White Pages
Search: Infoplease Info search tips
Search: Biographies Bio search tips
Encyclopedia

earthquake

earthquake, trembling or shaking movement of the earth's surface. Most earthquakes are minor tremors. Larger earthquakes usually begin with slight tremors but rapidly take the form of one or more violent shocks, and end in vibrations of gradually diminishing force called aftershocks. The subterranean point of origin of an earthquake is called its focus; the point on the surface directly above the focus is the epicenter. The magnitude and intensity of an earthquake is determined by the use of scales, e.g., the Richter scale and the Mercalli scale.

The Columbia Electronic Encyclopedia, 6th ed. Copyright © 2007, Columbia University Press. All rights reserved.

    • Cite
    • Print
    • Bookmark

More on earthquake from Infoplease:

  • Earthquakes! - Learn about how often earthquakes occur, what causes them, the difference between intensity and magnitude, and about tsunamis.
  • Earthquake - Earthquake 1906 April 18, San Francisco: earthquake accompanied by fire razed more than 4 sq mi; ...
  • Earthquake in Taiwan - Earthquake Factsheet Taiwan Tuesday, September 21, 1999, 1:47 a.m. local time by Ricco Villanueva ...
  • Earthquake in Turkey - Earthquake Factsheet Learn earthquake basics in Earthquakes 101. Earthquake epicenter: near Izmit, ...
  • Earthquakes: magnitude, deaths, frequency, size - Find information about the largest earthquakes on record, recent earthquakes, magnitude and frequency of earthquakes, and deaths from earthquakes worldwide each year.

See more Encyclopedia articles on: Geology and Oceanography


Premium Partner Content
HighBeam Research

Related content from HighBeam Research on: earthquake

Additional search results provided by HighBeam Research, LLC. © Copyright 2005. All rights reserved.