Earthquakes

Reference: United States Geological Survey

Disclaimer: This earthquake list was compiled at the Arkansas Geological Survey (AGS), but no warranty, expressed or implied, is made by the AGS regarding the accuracy of this information and location of earthquake epicenters, nor shall the act of distribution constitute any such warranty. The AGS does not guarantee this information to be free of errors and is not liable for interpretations generated from this data or decisions based thereof. Data users are cautioned to consider carefully the provisional nature of the information before using it for decisions that concern personal or public safety or the conduct of business that involves substantial monetary or operational consequences.

Download 2008 Arkansas Earthquake Spreadsheet

Download Arkansas Earthquake Archive

This earthquake archive list was made from a selection of seismic events that have occurred from 1699 to present in Arkansas. The seismic data have been cited from publications of the Center for Earthquake Research and Information (CERI) at the University of Memphis, the Department of Earth and Atmospheric Sciences at Saint Louis University, the United States Geological Survey (USGS), the Eastern Section of the Seismological Society of America and the University of Arkansas at Little Rock. We extend our appreciation to John David McFarland (Arkansas Geological Commission) for compiling the original earthquake database.

New Madrid Seismic Zone

This map depicts the locations and magnitudes of selected seismic events in New Madrid seismic zone of Northeast Arkansas. On December 16, 1811 residents living in the region near New Madrid, Missouri were jolted awake at 2:15 AM by a major earthquake. The shaking was felt as far away as New England and Canada. Scientists estimate that this event measured over a M7.0 (Johnston and Schweig, 1996). This marked the first of a series of powerful earthquakes that spanned a three-month period. Hundreds of aftershocks were reported for over a year.

Since that time, at least 20 damaging earthquakes have occurred in the NMSZ (Nuttli, 1982). An estimated M6.0 earthquake was reported near the town of Marked Tree, Arkansas on January 4, 1843. This earthquake caused the land to subside forming new lakes and did damage to chimneys and brick structures (Jackson, 1979). A M5.0 earthquake was recorded on March 24, 1976 in Poinsett County. This earthquake was felt over an area of 174, 000 sq. miles (280,000 sq. kilometers) bounded by Centralia, Illinois; Hopkinsville, Kentucky; Nashville and Clifton, Tennessee; Birmingham, Alabama; Little Rock, Arkansas; and Jefferson City, Missouri. In Arkansas, multiple cities reported an Intensity VI. Power outages, downed telephone lines in Jonesboro, broken windows in Paragould, cracked plaster in Marked Tree, roof damage and fallen ceiling tile occurred as far away as Decatur, Arkansas (Jackson, 1979).

Other recent events in northeast Arkansas were felt near the towns of Caraway and Manila, Arkansas in Poinsett County in 2005. Both earthquakes registered a M4.1 with an Intensity V. Although significant damage has not been reported in recent years, the NMSZ is still considered active and is potentially capable of generating powerful earthquakes.

The Enola Swarm Area

Adapted from John David McFarland III

The Enola swarm was initiated by a magnitude 1.2 earthquake recorded on January 12, 1982 near the town of Enola in Faulkner County, Arkansas. Since then, over 40,000 seismic events have been recorded in the Enola area. Most of the recorded seismic events are microquakes, but at least 93 earthquakes have been felt in the local area by at least one person during the first year of seismic activity. Earthquake magnitudes have not exceeded a 4.5, which occurred on Jan. 21, 1982. No structural damage has ever occurred, although there have been reports of broken china.

This map represents only a small sampling of seismic events that have occurred in the Enola swarm area since 1982. Events that are more recent include a magnitude 4.4 on May 4, 2001 followed by aftershocks greater than magnitude 2.0 over several days. Approximately 2,500 seismic events were recorded in 2001 on a portable seismic network. The most recent seismic event was a magnitude 2.8 on October 17, 2006.

These earthquakes are not associated with the New Madrid seismic zone of northeast Arkansas and there is no history or research that suggests any cause/effect relationship between the two regions.

More information about earthquakes in Arkansas

References

Chiu, J., Johnston, A.C., Metzeger, A.G., Haar, L. and Fletcher, J., 1984, Analysis of analog and digital records of the 1982 Arkansas earthquake swarm: Bull. Seismol. Soc. Am., 74: 1721-1742.

Jackson, K. C., 1979, Earthquakes and earthquake history of Arkansas: Arkansas Geological Commission, Information Circular no. 26.

Johnston, A., et al, 1982, The Central Arkansas earthquake swarm: Tennessee Earthquake Information Center (TEIC) Special Report # 8, parts 1, 2.

Johnston A., and Schweig, E., 1996, The Enigma of the New Madrid earthquakes of 1811-1812: Annual Review, Earth and Planetary Sciences, Vol. 24, p. 339-384.

McFarland, J. D., 2001, Faulkner County Earthquakes: Arkansas Geological
Commission, Open-File Report.

Nuttli, O. T., 1982, Investigations of the New Madrid Earthquake Regions: Damaging Earthquakes of the Central Mississippi Valley, Geological Survey, Professional Paper 1236-B.