The Superstition Hills fault ( SHF ) lies between the Coyote Creek fault that ruptured during the 1968 event and the Imperial Fault that ruptured during the 1940 El Centro earthquake and the 1979 Imperial Valley earthquake . To the northeast are several cross faults that trend northeast . One of these faults ruptured during a large aftershock of the 1979 event and another slipped as the smaller of the two shocks during the November 1987 sequence . The first shock ( on what became known as the Elmore Ranch fault ) measured 6.2 Ms and the shock 11.4 hours later on the SHF measured 6.6 Ms. ( & ) '' ' Notes ' '' '' ' Sources '' '
1979 Imperial Valley earthquake
1979 Imperial Valley earthquake
San Jacinto Fault Zone