Which fault system caused the 1992 Landers earthquake in southern California?

The 1992 Landers earthquake ruptured faults in the Eastern California Shear Zone.

The magnitude 7.3 Landers earthquake struck southern California on 28 June 1992. Its rupture propagated through a linked group of faults, including the Johnson Valley, Homestead Valley, Emerson and Camp Rock faults. Together, these structures form part of the Eastern California Shear Zone.

The earthquake produced a surface rupture about 70 kilometres long and caused strong shaking across the Mojave Desert. One person died, and damage affected roads, utilities and buildings. A magnitude 6.4 earthquake struck near Big Bear roughly three hours earlier that day.

Although the San Andreas Fault is California’s best-known fault, it did not rupture in the Landers event. The earthquake helped scientists understand how strain can be distributed across several parallel and connected faults.