Researchers from the California Institute of Technology have detected movement in a fault line that has never had movement detected before. The scientists, working with NASA’s Jet Propulsion Laboratory, found that part of the Garlock fault has slipped 0.8 inch (or about 2 centimeters) near its surface since July. The details of the discovery have been published in the journal Science.
The Garlock fault is a major fault line that runs more than 180 miles from the San Andreas Fault to Death Valley. According to researchers, the fault line could cause a magnitude 8 earthquake but it has remained relatively dormant over the years. Scientists say they’ve never seen this particular fault move until now.
Researchers were able to record the movement for the first time through satellite imagery and seismometer data. The data showed the slow detaching of land on the fault’s two sides. The movement would be virtually undetectable to an ordinary resident. The movement attributed to the quake is less than an inch along the surface of the fault.
The fault line slippage is believed to have been triggered by the series of earthquakes in the Ridgecrest area in July. The main quake in that series was the biggest earthquake to hit Southern California in 20 years and it was followed by more than 100,000 aftershocks in the surrounding area over 21 days. The ruptures in the Ridgecrest earthquake sequence ended just a few miles from the Garlock fault.
The movement is not an indication that an earthquake is imminent on the Garlock fault. The recorded movement is believed to have happened a few hundred feet below the surface of the fault, while a major earthquake is likely to occur about 10 to 15 kilometers deep. However, if an earthquake along the Garlock fault were to occur, it could damage the region’s nearby oil and agriculture hubs, along with military bases near the fault line.