Scientists seek local help in studying New Madrid fault

POPLAR BLUFF, Mo. -- Scientists are seeking local participation in research that may help determine the cause and frequency of earthquakes in the New Madrid Fault Zone.

It has long been known that an unseen and unknown force beneath the surface of Southeast Missouri can produce some of the most damaging and widely felt earthquakes in the continental United States.

Data collected from 43 earthquake recording stations to be located in Missouri and Iowa for a two-year period could assist in answering many questions surrounding these events, according to Dr. Stephen Gao, project organizer with the Missouri University of Science and Technology in Rolla.

The equipment is part of the National Science Foundation's EarthScope project. Since 2004, a transportable array of 400 seismic stations has been moving from west to east across the United States.

Members of the project are asking local landowners to volunteer space for about six seismic stations, which will be located in the surrounding area.

"We want to use these to see what is going on beneath the surface of the earth," Gao said. "We want to see what rocks are there, what deformations are there. Things like that could tell us something about the process that produces earthquakes. What is seen on the surface of the Earth is a the result of the process occurring beneath the surface."

The project is also expected to offer an improved understanding about the structure, dynamics and evolution of the earth.

Stations need to be placed in a quiet area, away from busy roads, but where a cell phone signal can be found and there is no chance of flooding, Gao said.

Two teams of students have been working since May to choose Missouri and Iowa's array locations, with more than 20 spots decided. They are ready to start looking at this area now, Gao said.

The stations will be put in place in 2010 and 2011.

This project is needed because there are so few seismic stations in the central part of the country, compared to the dense network established on the west coast, he continued.

"In Southeast Missouri, we don't know why huge earthquakes have happened here. We don't know the time interval between earthquakes," Gao said. "This will lay the ground so that in the future we may eventually be able to predict when earthquakes are going to occur."

It is believed there are three to five faults in the New Madrid Fault Zone.

This area is considered to be a stable continental region, many miles from the tectonic plate boundaries where 95 percent of earthquakes occur.

EarthScope equipment tracks quakes and seismic waves from events in the immediate area, as well as around the world.

This should allow scientists to map the Earth's interior through the computer-intensive technique of seismic tomography. This method is similar to a CAT scan used by doctors to map the human body.

"Using computers to analyze the waves recorded by the instruments, we can see the (inner) structure of the earth," Gao said.

The EarthScope project is expected to have covered the entire U.S. by 2014. Geophysicists around the world can access information recorded by each station within seconds after an earthquake.

Gao can be reached by e-mail at sgao@mst.edu. More information about the project can also be found on the web at: http://web.mst.edu/~sgao/USArray.

Anyone interested in geological sciences and engineering will also find a very good program at the Missouri University of Science and Technology, Gao said.