JEFFERSON CITY, MO, NOV. 8, 2002 -- The 7.9 magnitude earthquake that struck a remote area in central Alaska last Sunday had noticeable impacts here in Missouri, according to the Missouri Department of Natural Resources. Staff in the department’s Geological Survey and Resource Assessment Division have received reports from citizens and from water well drillers.

Numerous wells have developed muddy or cloudy water. "Large distant earthquakes can affect water levels in wells and can cause sediments in the rock and soil to be shaken and suspended in well water," said Dave Hoffman, an earthquake geologist. "Reports and records document these same phenomena from the Good Friday earthquake, a 9.2 magnitude event, that took place in Alaska in 1964."

In 1964, the Geological Survey’s groundwater level monitoring network had several wells where the water level fluctuated significantly. The same thing has happened as a result of Sunday’s Alaskan earthquake. Geologists examined data from the groundwater level monitoring network and found significant changes in water level in at least 21 of the more than 70 wells that are in the monitoring network. These wells are located in 19 different counties, primarily in southern Missouri.

Water levels went up in some wells and down in others. Changes in the water level ranged up to 2 feet. Because it takes a matter of minutes for shock waves to travel through the earth from Alaska to Missouri, the water level effects started between 4:30 and 5 p.m. Sunday.

Late Sunday afternoon, a Harrisonville man noticed that the water in his small pond was sloshing back and forth.  He did not feel the ground move and was puzzled until he heard about the earthquake. This is similar to news media reports on this earthquake from Washington and Louisiana where bodies of water were also disturbed.

"Fortunately, the Sunday quake did minimal damage in Alaska due to its remote location," said Mimi Garstang, state geologist and director of the department’s Division of Geological Survey and Resource Assessment Division. "The occurrence should remind Missourians that we need to be concerned and prepared for the major effects of large earthquakes close to home, such as those that can be generated by the New Madrid seismic zone and other Mid-West earthquake source areas."

Understanding the nature and behavior of local earthquakes and applying that information to engineering design, construction and maintenance of manmade structures is essential to reducing the impact of earthquakes. It is failure of the manmade structures that cause most of the injuries, property damage and economic losses associated with earthquakes.

Citizens can submit on-line Internet reports on the effects of an earthquake to the U.S. Geological Survey at http://pasadena.wr.usgs.gov/shake/. You can view groundwater level monitoring network data for Missouri at http://waterdata.usgs.gov/mo/nwis/current/?type=gw. Click on one of the wells. Lawrence County – Aurora is a good example of an affected well.

For more information, please contact the department’s Geological Survey and Resource Assessment Division at P.O. Box 250, Rolla, MO 65402, 573-368-2144, or by e-mail at nrhoffd@dnr.state.mo.us.

Missouri Earthquake Map