Seismologist Studies Dimensions, Dynamics of Ridgecrest Fault Line

A UC Riverside geophysics professor is taking measurements along fault lines running through Ridgecrest, California, to determine how the little-known fissures produced the July 4 earthquake and the bigger one that followed the next day, campus officials said Wednesday. Professor Abhijit Ghosh has planted 25 seismometers along the surface of the Ridgecrest faults to monitor activity since last month’s shakers and utilize that data to gauge what impact the lines are having on surrounding faults, including the well-known Garlock fault that stretches 150 miles, just southeast of Bakersfield, according to UCR. "These instruments are extremely sensitive," Ghosh said. "They can detect and locate even very tiny earthquakes very precisely." The professor acknowledged very little is understood about the main 40- mile Ridgecrest fault — until it got everyone’s attention with a 6.4- magnitude quake on July 4 and a 7.1-magnitude roller July 5, causing extensive damage to infrastructure in the community of Ridgecrest and around the neighboring China Lake Naval Air Weapons Station. Ghosh is hoping the readings, which give a three-dimensional view of fault lines’ composition, will enable seismologists to improve geophysical mapping of the region. The professor says he is keenly interested to know what influence the 7.1-magnitude quake may have had on tectonic plates moving within surrounding faults. "It’s not a matter of `whether’ there will be another large quake in California," Ghosh said. "It’s an inevitability. The more we understand about the physics behind earthquakes, the better we can prepare to combat their hazards." Ghosh dismissed the notion that a big quake provides a release of energy that lessens the likelihood of a similar temblor happening in the same area soon afterward. He said a bigger quake could strike at any time. "Be prepared," the professor said. "Seismic hazard levels are high in California, whether you live near Ridgecrest or not." His research is being funded, in part, by the National Science Foundation.