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Article: Oil wells cause earthquakes.
- Article from:
- Science News
- Article date:
- October 28, 1989
- Author:
CopyrightCOPYRIGHT 1989 Science Service, Inc. This material is published under license from the publisher through the Gale Group, Farmington Hills, Michigan. All inquiries regarding rights should be directed to the Gale Group. (Hide copyright information)
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Oil wells cause earthquakes
In 1958, a geologist calculated that injecting fluid into the ground increases the chance of earthquakes. Thirty-one years later, another geologist has shown the reverse: pumping gas or oil out of the ground can also trigger earthquakes.
Pumping out underground crude contracts the rock in oil reservoirs and sets up large pressure changes over short distances, Paul Segall of the U.S. Geological Survey in Menlo Park, Calif., calculates in the October GEOLOGY. Vertical contraction makes the ground above the reservoir sink, while horizontal stresses pull surrounding rock inward. If the pull becomes strong enough to shear the rock, ...