![]() |
|
| Date | 1 October 1987 |
|---|---|
| Magnitude | 5.9 Mw |
| Depth | 9.5 kilometers (5.9 mi) |
| Epicenter location | 34°03′40″N 118°04′41″W / 34.061°N 118.078°WCoordinates: 34°03′40″N 118°04′41″W / 34.061°N 118.078°W |
| Countries or regions affected | (Southern California) |
| Casualties | 8 killed |
The 1987 Whittier Narrows earthquake struck the southern San Gabriel Valley and surrounding communities of southern California at 7:42 a.m. (PDT) on October 1, 1987. The magnitude 5.9 earthquake was originally assigned a magnitude of 6.0 but was revised a few days later when additional data became available. Its epicenter was in the town of Rosemead, California, at a depth of 9.5 km.
The earthquake was caused by slip on a blind thrust fault near the northern end of the Whittier Fault, part of the Elsinore Fault Zone, on a previously unknown fault structure. There was no surface rupture. It has been proposed that the event occurred on an extension of the recently recognized Puente Hills thrust system.[1]
A magnitude 5.6[2] strike-slip aftershock occurred three days later, on October 4, causing additional damage, and one additional death.
Three people died as a direct result of the earthquake. One death was of a Southern California Edison worker buried by a landslide in the Muir Peak area of the San Gabriel Mountains while working with a crew installing the footings for a high tension power tower north of Pasadena, California. Lupe Elias-Exposito was killed when a concrete slab fell on her as she, her sister and a friend were exiting a parking structure at Caliornia State University, Los Angeles. Five other deaths are attributed indirectly to the event. About $358 million USD in damage resulted.[3]
The Whittier Narrows earthquake along with two other events - the 1983 Coalinga earthquake, and the 1994 Northridge earthquake, brought blind thrusts to the attention of seismologists and policy makers. As a result, other significant blind thrusts have been identified in Southern California.
|
|||||||||||
|
|||||||||||
|
|