L.A. moves, but not in the way expected

Researchers monitoring small ground motions along faults in Southern California

Map of the Los Angeles area shows land subsidence in summer of 1999. The largest drop, about 5.4 centimeters, was near downtown Santa Ana (arrow). The smallest drops were in the north and are shown in blue and violet. Bawden

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

region’s aquifers.