earthquakes

Each year instruments record about 800,000 earthquakes so small people can't feel them. On the other hand, between 1945 and 1986 earthquakes caused half of all the deaths due to natural disasters–about 1,198,000 fatalities. Of all the types of natural disasters (hurricanes, typhoons, volcanic eruptions, and so on), major earthquakes caused more deaths per disaster (6,272) than any other type. Little earthquakes we can't even notice; big ones can be catastrophic.

Some Sizes pages on earthquakes:

intensity (the Mercalli scale)

magnitude, including Richter magnitude

A list of some big earthquakes

information

National Earthquake Information Center
P. O. Box 25046
DFC, MS-967
Denver, CO 80225 USA
(303) 236-1510
northern/central California, (415) 329-4025.
southern California, (818) 395-6977.
For worldwide earthquakes over M5.5, including North America, (303) 273-8516.
All information is updated daily.