LOS ANGELES (AP) — The earthquakes that hammered the Southern California desert near the town of Ridgecrest last summer involved ruptures on a web of interconnected faults and increased strain on a major nearby fault that has begun to slowly move, according to a new study.

Ruptures in the Ridgecrest earthquake sequence ended a few miles from the Garlock Fault, which runs east-west for 185 miles (300 kilometers) from the San Andreas Fault to Death Valley.

The Garlock Fault has been relatively quiet for 500 years. It now has begun a process called fault creep and has slipped 0.8 inch (2 centimet...