Researchers monitoring small ground motions along faults in Southern California
ended up detecting an altogether different phenomenon: the rise and fall of the
ground as local governments pump billions of gallons of water into and out of the
In some spots–particularly in the 40-kilometer-long Santa Ana basin, southeast of
Los Angeles–the ground rises and falls up to 11 centimeters over the course of a
year. This periodic movement, which the scientists say isn't linked to Southern
California's earthquake activity, hasn't been measured before, says Gerald W.