San Andreas Fault Making Large-Scale Vertical Movements

For the first time, scientists have produced a computer image showing huge sections of California rising and sinking around the San Andreas fault -- the result of seismic strain that will be ultimately released in a large earthquake, it was reported Thursday.

The San Andreas fault is California’s longest earthquake fault, and one of the state’s most dangerous. The 1906 San Francisco earthquake happened on the San Andreas fault.

Scientists have long expected that parts of California are rising and other parts sinking around the fault in a way that is ongoing, very subtle and extremely slow, the Los Angeles Times reported.

California sits on the border of two gigantic tectonic plates -- the Pacific and North American -- that are constantly grinding past each other. But actually observing how California’s landscape is rising and falling from seismic strain has been an elusive goal, until now.

In a study published in the journal Nature Geoscience on Monday, scientists found that much of the Los Angeles Basin, Orange County, San Diego County and the Bakersfield area are sinking 2 to 3 millimeters a year. By contrast, Santa Barbara and San Luis Obispo counties, and a large portion of San Bernardino County, are rising at the same rate.

"Once there is a major event, all of that energy gets released,” Sam Howell, a doctoral candidate in geophysics at the University of Hawaii at Manoa and the lead author of the report, said in remarks reported by The Times.

--City News Service; Image via Shutterstock