Knowledge gained from studying earthquake waves has been applied in various fields. In the search for oil and gas, we make similar waves under controlled conditions with dynamite and learn from them where there are buried rock structures favorable to the accumulation of these resources. We have also developed techniques for recognizing and locating underground nuclear tests through the waves in the ground which they generate.

The following discussion of this subject has been adapted from the book Causes of Catastrophe by L. Don Leet.

At twelve minutes after five on the morning of Wednesday, April 18, 1906, San Francisco was shaken by a severe earthquake. A sharp tremor was followed by a jerky roll.