Nebraska scientists want to install 10 seismometers
LINCOLN, Neb. (AP) — University of Nebraska-Lincoln scientists want to install 10 seismometers to study what geologists call an earthquake swarm in central Nebraska.
Three university professors, Cara Burberry, Irina Filina and Mindi Searles, are preparing a grant application to the National Science Foundation to pay for the installation and operation of the seismometers. They want to place the devices near Arnold, where about 20 mild earthquakes have been recorded since April, the Lincoln Journal Star reported .
A 3.5-magnitude earthquake was most recently recorded on July 26.
“What is striking about this is they’re all in a relatively short period of time,” said Filina, a geophysics professor at the university. “And that’s suspicious.”
The scientists want to study the source of the earthquakes, why they’re growing in volume and intensity and whether they’re natural or caused by humans. It’s known that the earthquakes are coming from the movement of a historically quiet basement fault, which is a crack in crystalline rock beneath the Sandhills.
“Faults can sit there and look pretty for hundreds of years,” said Burberry, an associate professor of geology. “But then something changes the stress on it, something changes the forces on it, and they move and shake, and we’re trying to get to what that reason might be.”
The seismometers could help the scientists identify the fault and determine its depth.
Nebraska, which has been considered tectonically quiet, lacks sufficient data because there are only a few seismometers monitoring movement below the surface, Filina said. The existing seismometers aren’t close enough to Arnold to provide insight on the earthquake hotspot.
“We want to understand them,” she said. “To do that, we have to have a good record of them.”
The professors’ estimated $200,000 project could launch next year, if approved. The project would record data for two years.
Information from: Lincoln Journal Star, http://www.journalstar.com