More than 10 years ago Utah State University geologist Susanne Janecke and her team began a search for a fault zone at the southern tip of the San Andreas Fault, an area that had been obscured by flooding a hundred years earlier.
For decades, geologists have theorized the next big California earthquake in that region could start near the southern tip of the San Andreas Fault. Dr. Janecke and her team felt there might be a second major fault zone southwest of the one that was known at the time.
They set out using Google Earth imagery and other tools to find that second major fault zone, and they did.
”We found there was a major fault zone,” says Janecke. “We expected it to be a relatively short one. It turns out that especially because of the research of our colleagues, Patricia Persaud and Gary Fuis and others, that we can now trace the fault all along the northeast margin of Coachella Valley and we’re fairly confident that it connects to the previously known fault for now a 100 kilometer long fault trace.”
While she admits it is difficult to predict such events, Dr. Janecke’s research indicates an earthquake is way overdue in the area.
”The research by many seismologists who trench across active faults shows that the last major earthquake in this part of the San Andreas fault was about 300 years ago. On average, earthquakes have occurred there about every 180 years or so. So it’s over a hundred years overdue, if that regular cycle repeats.”
She said their research has revealed what she calls critical evidence about the possible starting point of the next major earthquake on the San Andreas Fault.