With the Mississippi River being traversed by many water vessels, a new comer to the Helena portion of the river may go unnoticed. One such boat is currently on the river and the passengers on the boat are studying the seismic activity of the New Madrid Fault line. The University of Memphis Center for Earthquake Research and Information (CERI) in collaboration with the University of Texas at Austin, the University of Texas Institute for Geophysicists (UTIG) started gathering seismic information on the long term deformation of the Mississippi Embayment this week and plan to continue until 2010. In English, the scientists are gathering earthquake data on the New Madrid Fault and have started their research at Helena.
Information gathered from the research initiative say that although the theory of plate tectonics revolutionized the understanding of the earthquake processes, it does not explain why earthquakes occur in regions distant from plate boundaries where deformation rates are low and where plate motions supply insufficient driving energy. Deformation rates are gathered from data compiled on energy within the Earth’s upper crust. CERI is on a race to find the driving question behind the faults in the mid-American region of the U.S.
As part of this seismic experiment the group will acquire 300 km of high-resolution seismic reflection data and chirp data along the Mississippi River, from Helena, to Caruthersville, Mo. The study area is located in the Mississippi embayment, south of the New Madrid Seismic Zone (NMSZ), an extraordinarily active seismic area in the heart of the North American Continent, 2,000km from the nearest plate boundary. The CERI Web site says that in the last six months, 120 earthquakes have occurred in the fault area. Historically, the high level and frequency of the quakes clash with the flat topography of the Mississippi Embayment. Scientists have developed theories and say that more information is needed to figure out the “paradox.” The theories say that quake activity in the designated area may be either be intermittent, or that the fault line may be very young or it migrates throughout a broad region at the continental or regional scale.
In order to test the hypotheses CERI will gather information from the river. Oliver Boyd, research geophysicist at the University of Memphis (CERI) says that taking readings of the crust in the river allows for clearer data. CERI says that by using the river to gather the data, money can be saved as well as time.
CERI thinks that there may be more than one fault or seismic source.
“The seismic acquisition, calibrated to illuminate the shallow section, will provide unprecedented high-resolution images of the Mississippi River sediments and of the suspected faults concealed under the subdued topography, providing detailed information on the partitioning of the deformation among key structures beyond the limit of the NMSZ,” said a press release from the CERI Web site.
“We’re trying to improve the data on the active New Madrid Fault, structural make-up and just get a better understanding,” said Boyd.
He added that since the Army Corps of Engineers is involved they may be looking at how earthquakes affect levies and bridges near the fault line. Boyd says the group is headed north and may be in the area for about a month.