GEOLOGIST SAYS BIG QUAKE FAR IN FUTURE; NEW STUDY ALONG NEW MADRID FAULT

A catastrophic earthquake along the New Madrid Fault likely won't occur for thousands of years, a University of Missouri-Columbia geologist says.

It could take 14,000 years for an earthquake measuring 8.0 on the Richter scale to occur, said Joe Engeln, an associate professor of geological sciences.

Engeln's findings were published in Science magazine this week.

"We think the risk of a great earthquake is much, much smaller than had been projected," he said Thursday.

"This doesn't say there won't be damaging earthquakes," the geologist said. "There is still a very good chance that ther will be a damaging earthquake there in my lifetime."

But a killer quake isn't just around the corner, he said.

Engeln said he and scientists from two other institutions used a global positioning satellite system to measure movement along the fault. To measure movement, Engeln and his colleagues drilled steel rods 6 to 8 inches into the ground where there was solid rock. In other areas where the ground was soft, the rods extended as deep as 60 feet.

A plastic sheath was put around each rod to protect them from surface soil movement.

In all, the scientists marked 24 spots along the New Madrid Fault extending from central Tennessee through Southeast Missouri to central Arkansas. The Southeast Missouri sites included the Malden and Caruthersville areas. The rods were installed in 1991. The researchers revisited the sites in 1993 and again in 1997.

Using global positioning satellite technology, the researchers looked for small changes in the placement of the rods. What they found were only a few millimeters of movement.

"The data that we have collected along the New Madrid Fault suggests that strain and stress on the fault are not building up fast enough to cause large earthquakes very frequently," Engeln said.

While earthquakes do shake the New Madrid region from time to time, they are often very small and detected only with geological equipment.

Even the major earthquakes along the fault in 1811-1812 may not have registered 8.0 on the Richter scale, Engeln said. A series of three earthquakes were felt as far away as Boston and Philadelphia those years.

"The rock beneath the surface along the New Madrid Fault is very hard and will carry a vibration very well, and new evidence is pointing toward a smaller earthquake, probably somewhere around a 7.0 on the Richter scale," Engeln said.

Arch Johnston, a seismologist at the University of Memphis, challenged the conclusions of the latest study. He said movement along the fault could be as much as 10 millimeters a year, which would indicate a major quake could occur every 400 to 600 years.

Those involved in the study insisted that scientists in the past had overestimated the danger.

Engeln said his findings shouldn't be seen as an excuse to abandon earthquake preparedness efforts or construct quake-resistant buildings. But he said engineers may want to design buildings that can withstand a 7.0-magnitude quake rather than a larger quake.

Earthquake education specialist David Wildharber said Engeln's study doesn't eliminate the need for earthquake preparedness. Wildharber works in the Center for Earthquake Studies at Southeast Missouri State University. He regularly speaks to school groups about the danger of earthquakes and how to best prepare for them.

The possibility of a 6.0-to-7.0 magnitude quake is a concern, he said. Such a quake could occur within the next 50 years, he said. "It would cause damage to structures as far away as St. Louis and Memphis," Wildharber said.

"The last earthquake of that magnitude was in 1895," he said. It was centered near Charleston.

Earthquake education and mitigation efforts are important, Wildharber said. "I think we should continue full speed ahead."

The Associated Press contributed to this report.