Oklahoma Earthquake History
The series of great earthquakes in the New Madrid, Missouri, region in 1811 - 1812, and a strong earthquake centered in Arkansas (October 22, 1881) were probably felt in the area that is now Oklahoma.
The first earthquake known to have centered in the State occurred in September 1918. A series of shocks at El Reno produced only minor effects; the strongest was intensity V on September 10. Objects were thrown from shelves. Other shocks occurred on the next day.
On December 27, 1929, another tremor centered in the same area was felt in portions of central and western Oklahoma. Some plaster cracked and at least one chimney fell (intensity VI) at El Reno. In addition, clocks stopped, objects moved, and some reports indicated the walls and floors seemed to sway. In several cities, people rushed from their homes in alarm. The total felt area included about 20,000 square kilometers.
The magnitude 5.5 April 9, 1952, earthquake centered near El Reno affected most of Oklahoma and parts of Arkansas, Iowa, Kansas, Missouri, Nebraska, and Texas. Damage from the 10:30 a.m. CST earthquake was not extensive, but many people in the epicentral area were alarmed, some to near panic. Portions of chimneys fell in El Reno and Ponca City (intensity VII). Bricks loosened from a building wall and tile facing of commercial buildings bulged at Oklahoma City. Also, plate glass windows were shattered in the business district of El Reno. The total damage amounted to several thousand dollars.
Aftershocks were felt on April 11, 15, and 16, July 16, and August 14; an earthquake that was felt (IV) at Holdenville and Wewoka on October 7 apparently was unrelated to the April 9th event. Homes and buildings shook and some persons were awakened (V) at El Reno from the April 16th shock, which occurred 5 minutes after midnight. Felt reports were also received from Kingfisher, Oklahoma City, Tulsa, and Union City.
http://earthquake.usgs.gov/earthquakes/states/oklahoma/history.php
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