Earthquake Information

Chronological Earthquake Index

Whittier Narrows Earthquake

TYPE OF FAULTING: thrust
TIME: October 1, 1987
LOCATION: 34° 03.68' N, 118° 04.71' W 11 km (7 miles) southeast of Pasadena
MAGNITUDE: M_L5.9
DEPTH: 14.6 km

This earthquake occurred on a previously unknown, concealed thrust fault approximately 20 km east of downtown Los Angeles, California. It resulted in eight fatalities and $358 million in property damage. Severe damage was confined mainly to communities east of Los Angeles and near the epicenter. No severe structural damage to high-rise structures in downtown Los Angeles was reported.

The most severe damage occurred in the "Uptown" district of Whittier, the old downtown section of Alhambra, and in the "Old Town" section of Pasadena. These areas had high concentrations of unreinforced masonry buildings. Residences that sustained damage usually were constructed of masonry, were not fully anchored to foundations, or were houses built over garages with large door openings. Many chimneys collapsed and in some cases, fell through roofs. Wood frame residences sustained relatively little damage.

Damage to the bell tower and exterior structure of the San Gabriel
Civic Auditorium resulting from the Whittier Narrows mainshock and
large aftershock. (Photo Credit: G. Reagor, U.S. Geological Survey)