04/18/2008

By JIM SALTER  / Associated Press

Missouri Department of Transportation inspectors on Friday examined hundreds of bridges in the eastern part of the state, checking for possible damage from a moderate earthquake.

Friday evening, MoDot said it had found no problems after inspecting 2,500 bridges.

The magnitude 5.2 quake just before 4:37 a.m. centered in southern Illinois, about 130 miles from St. Louis. It awakened and startled residents in several parts of Missouri. Dozens of aftershocks, including one with magnitude 4.5 about 10:15 a.m., followed. But MoDOT said that aftershock wasn't strong enough to damage a bridge, so re-examination of structures looked at earlier Friday wasn't necessary.

MoDOT bridge maintenance engineer Scott Stotlemeyer said hundreds of inspectors were called in.

"If we find any damage we'll deal with it right away, and we won't hesitate to close a bridge," he said.

Inspectors were searching for cracks or buckling in the bridge deck, loose pavement, bent beams or girders, missing bolts, or misaligned curbs or rails.

There have been no reports of injuries or serious damage in Missouri.

Gov. Matt Blunt ordered all agencies of the Department of Public Safety to be prepared to help in case of emergency.

Earthquakes are a serious concern in Missouri because of the New Madrid fault line centered around the Missouri Bootheel town of New Madrid. A series of devastating quakes there shook much of the eastern U.S. in 1811 and 1812.

Tim Kusky, director of the Center for Environmental Sciences at Saint Louis University, said experts believe a major quake should happen along the fault about once every 400 years.

Friday's quake occurred along an extension of the New Madrid fault known as the Wabash fault. Kusky said the quake, while startling, is not that unusual for the region.

"The type of activity that we have in the New Madrid zone is that every few years we have a magnitude 3, 4, 5 earthquake," Kusky said. "This is kind of the high end, but it happens."

The quake was felt as far away as Indianapolis, Chicago, even Pittsburgh. Kusky said Midwestern quakes tend to be felt at greater distances than those in California.

"The rocks here and across much of the central United States are strong, hard rocks, and they transmit the energy very efficiently. So they can be felt far away," Kusky said. By contrast, he said, California has softer rocks so a quake of similar magnitude would be more localized.