GPS readings suggests 'considerable' movement along San Andreas Fault
Researchers say GPS technology reveals new evidence of significant movement along the San Andreas Fault.
Findings published in the journal Nature Geoscience indicate a "small-amplitude, but spatially considerable, coherent pattern of uplift and subsidence straddling the fault system in southern California."
Researchers found "lobes" of earth on either side of the fault that move a few millimeters each year. Seismologists had previously predicted such movement, but had been unable to isolate the pattern, according to a press release on the findings.
The GPS readings from from the EarthScope Plate Boundary Observatory's GPS array were previously available, but a team from the University of Hawaii at Manoa said they used advanced statistical analysis to remove "noise" in the data created by precipitation, water pumping and other factors. The result was a clear pattern of movement around the fault.
"While the San Andreas GPS data has been publicly available for more than a decade, the vertical component of the measurements had largely been ignored in tectonic investigations because of difficulties in interpreting the noisy data," Samuel Howell, doctoral candidate in the School of Ocean and Earth Science and Technology, said in the release. "Using this technique, we were able to break down the noisy signals to isolate a simple vertical motion pattern that curiously straddled the San Andreas fault."
Researchers say this evidence may help future earthquake mapping and prediction efforts by limiting the known areas of movement.