Earthquake felt in many Missouri towns; local public safety officials stress the need to be prepared

On Friday, April 18, many areas of Missouri experienced the aftershocks of a 5.2, and a 4.5 earthquake in Mount Carmel, Ill., along the Wabash Seismic Zone. Mount Carmel is approximately 130 miles east of St. Louis. Early this morning, Gov. Matt Blunt activated state agencies to respond to local requests for assistance. The State Emergency Management Agency has activated portions of the Earthquake Annex and is contacting local jurisdictions for damage information.

So far, little damage has been reported, even at the quake's epicenter in Illinois, but according to the Missouri Department of Natural Resources, the primary quake was felt in Illinois and Missouri as well as some areas as far from the epicenter as Kansas, Georgia and Michigan.

In Nevada, no one has reported feeling any indication of the quake, but local public safety officials say there is a plan in place for just such situations.

Nevada's emergency management director, Gary Herstein, said that a portion of a recent FEMA conference highlighted earthquake risk in the state.

Herstein said that the group reviewed maps of the 1811-'12 New Madrid earthquakes -- the largest recorded in Missouri; and through an assessment of damage reports, there was little damage in the Nevada area; however, there appears to have been a much more significant pocket of damage a short distance north of Nevada, in the Linn County, Kan., area.

According to the U.S. Geological Survey, the largest earthquake in Kansas occurred in the Manhattan area, in 1867. The USGS said that during that quake, people suffered minor injuries. stones were loosened from buildings and one side of a building housing a newspaper office in Paola, Kan., fell away.

Herstein noted that there's another fault in central Kansas that could impact this area if a serious quake were to occur along that line.

Herstein said it's likely that if either fault were to shift, the role of local public safety officials would be a support role -- responding to help other communities and perhaps experiencing an influx of people leaving more heavily impacted areas.

"There's a very extensive statewide plan," he said, that would be activated in a major event.

A State Emergency Management Agency map suggests the most severe impact that might happen in Vernon County, Mo., and Bourbon County, Kan., in the event of a 6.7 earthquake on the New Madrid fault. Most people would feel movement, doors could swing open or closed, windows could crack in some cases, small objects could move or fall over. In a 7.6 quake, some areas could experience broken dishes, cracked plaster and people could have trouble walking. Some bells in churches or chapels could ring. The quakes in New Madrid, 1811 and 1812, are estimated to have been somewhere around 7.2-8.1, according to the U.S. Geological Survey.

As to the local potential for damage, "Just based on what happened in the past, the information that we have, it doesn't look like we would get much in the way of damage. We could feel it; maybe a few pictures would fall off the walls; maybe the contents in the refrigerator would be shaken out; things like that. But you never know. Be prepared," Herstein said.

According to a report in the Southeast Missourian, Cape Girardeau, Dr. Nicholas Tibbs, professor emeritus of geosciences at Southeast Missouri State University, it is unlikely that the West Salem earthquakes, located in the Wabash Valley fault zone, would trigger a larger earthquake in Southeast Missouri along the New Madrid fault.

"My first reaction would be no," he said. He added that earthquakes on rare occasions have been known to trigger earthquakes in other faults.

The second quake felt in southeast Missouri was only one of many aftershocks from the early morning quake, Tibbs said.

Dave Overhoff, geo-hazards geologist with the Missouri Department of Natural Resources' Division of Geology and Land Survey in Rolla said, "While the movement was along the Wabash Valley Fault System, this system is independent of the New Madrid Seismic Zone." Scientists believe that the Wabash Valley Fault System runs perpendicular to the New Madrid Fault, along the north end of the system.

Moderately damaging earthquakes occur on the Wabash Valley fault about once every decade or two, the DNR said. Smaller earthquakes are felt about once or twice a year, which is considerably less active than the New Madrid Seismic Zone.

The largest recorded earthquake on the Wabash Valley Fault System was in 1968, which registered magnitude 5.4.

On June 18, 2002, a 5.0 magnitude earthquake struck the Evansville, Ind., area.

The DNR has a plan in place to implement a clearinghouse for the scientific community, should a significant earthquake occur in Missouri.

Overhoff and other earthquake experts from around the nation also plan to convene next week in Seattle, Wash., for the National Earthquake Conference to discuss the latest research on earthquakes and the generation of tsunamis. Forty states have some risk of earthquake.