They found widespread seismic activity in an area they are calling the Ste. Genevieve Seismic Zone, thus increasing the chances of earthquake activity for the area, according to an IU news release.
The areas affected include southwestern Illinois and eastern Missouri.
The study was published in the November/December issue of Seismological Research Letters.
This finding is the first result published from the OIINK geophysical research project. The acronym OIINK refers to the locations in which 140 seismic detectors were ?installed.
These areas include the Ozarks, Illinois, Indiana and Kentucky. OIINK is a collaborative research effort involving IU, Purdue University, the University of Illinois and the Illinois and Indiana state geological surveys, according to the University.
Michael Hamburger, professor of geological sciences at IU-Bloomington, co-authored the study.
“It’s an underappreciated zone of seismic activity that has potential implications for St. Louis and other populated areas in eastern Missouri and Southwestern Illinois,” he said in the release. “It’s comparable to the Wabash Valley Seismic Zone in western Indiana, which is capable of producing moderate-sized earthquakes every few decades and perhaps has the potential for larger earthquakes.”
The central United States is not often thought of as an area at risk for earthquakes, but the area remains an active seismic zone, according to the ?University.
Lead author of the study was Xiaotao Yang, an IU doctoral student in the Department of Geological ?Sciences.
Additional co-authors included IU geologist Gary Pavlis, principal investigator for the OIINK project; Elizabeth Sherrill, an IU undergraduate; and John Rupp, senior research scientist with the Indiana Geological Survey.
Hersh Gilbert of Purdue University, Stephen Marshak of the University of Illinois and Timothy Larson of the Illinois State Geological ?Survey also contributed.
The seismic zone discovered is near populated areas and is an area of geological interest, according to the University.
The area partially encompasses the Ste. Genevieve Fault Zone. This fault zone is the divide between the billion-year-old Ozark Dome and the younger ?sedimentary rock that makes up the Illinois Basin.
One of OIINK’s objectives is to look at the relationship between faults on Earth’s surface and seismic activity that takes place deep underground.
The $1.3 million project will take place over four years.
This study is based on results collected during the first phase of the project, according to the University.
One hundred forty state-of-the-art seismographs have been put in place in a large area of the Midwest.
The seismographs’ sensitivity allowed researchers to record many small earthquakes with magnitudes as low as 1.3, too low to be felt on the surface.
The devices were also able to distinguish seismic activity from quarry and coal mine blasts, which occur throughout the region.
Anna Hyzy
