LECTURER EXPLAINS NEW MADRID QUAKES

With last Friday marking the 185th anniversary of the biggest of the New Madrid earthquakes of 1811-12, historian Tim Keel took about 13 people through a history of the event Sunday at the Cape Girardeau Public Library.

Starting off with Native American legends about the disaster, Keel presented a slide show and information-filled seminar derived from more than 170 research papers and 13 books in his collection about the New Madrid quakes.

"He's a good storyteller," said Betty Martin, a library worker who sat in on the presentation. "He has a nice way of presenting facts and actual events from the 1800s. He brought out some geological facts that would be pretty dry otherwise."

Keel said this is a hobby for him and that his tour, which included New Madrid last week, is a vacation for him.

According to Keel, some researchers believe three separate earthquakes erupted along the New Madrid fault between Dec. 26, 1811, and Feb. 7, 1812.

The first quake originated in the Midwest at 2:30 a.m. and was felt at 3:40 a.m. in Pittsburgh, Penn. Reports from that time said the earth whistled and roared in Arkansas as the shock waves approached, Keel said.

Two islands in the Mississippi River were destroyed by the quakes and three small communities along the river's edge were buried or swept away.

Keel said the New Madrid earthquakes are unique for a number of reasons. Geographically, the fault is unusual because it is not the dividing line between two tectonic plates like the San Andreas Fault in California. The New Madrid Fault, which is also buried beneath hundreds of feet of sand and rock, is a rift that quit dividing 800 million years ago, Keel said.

"In the central U.S. there are no plate boundaries so it was not plate tectonics that caused the earthquakes directly," he said. "This area has a number of complex faults that filled in because of sediment from the Mississippi. That's what makes it even more of a mystery because they can't even observe the faults directly."

There are other intra-plate seismic zones, Keel said, that have produced earthquakes in India and China. "But it is the New Madrid Seismic Zone that has produced the largest of these intra-plate earthquakes," he said. "The great shock of Feb. 7, 1812, even exceeded the 1906 San Francisco quake."

After a presentation, Keel is often asked whether the Mississippi River changed its course because of the earthquakes.

"I have not read anything that says the course of the Mississippi was altered by the quakes," he said. "The river was very much changed visually because of the fallen banks and many of the islands had serious damage done to them."