  Los Angeles Las Vegas San Diego  | |
| UTC time | 1987-11-24 01:54:14 |
|---|---|
| 1987-11-24 13:15:56 | |
| ISC event | 453653 |
| 453722 | |
| USGS-ANSS | ComCat |
| ComCat | |
| Local date | November 23, 1987 |
| November 24, 1987 | |
| Local time | 17:54 PST |
| 05:15 PST | |
| Magnitude | 6.0 Mw |
| 6.5 Mw | |
| Depth | 2.3 km (1.4 mi) |
| 7.5 km (4.7 mi) | |
| Epicenter | 33°05′24″N 115°47′31″W / 33.090°N 115.792°W |
| Type | Strike-slip |
| Areas affected | California and Mexico |
| Total damage | US$3 million |
| Max. intensity | MMI VI (Strong) MMI VII (Very strong) |
| Casualties | 2 dead, 94 injured |
The 1987 Superstition Hills earthquake affected the Imperial Valley of California and Baja California on November 24, nearly 12 hours after a Mw 6.0 foreshock, called the Elmore Ranch earthquake. The mainshock, measuring Mw 6.5, struck at 17:54 PST, along the Superstition Hills segment of the San Jacinto Fault Zone. The earthquake generated a 27 km (17 mi) surface rupture with additional postseismic slip continuing for a year.
The earthquake caused damage amounting to US$3 million. Damage was considerable in Mexicali, were two people were killed and 50 people sustained injuries. Another 44 people were injured in the Imperial Valley. Buildings El Centro, Imperial, and Westmorland sustained collapsed chimneys, ruptured pipes and shattered windows. The rebuilt Imperial County services building, which replaced an originally five-story structure, remained structurally intact. Damage to canal infrastructure cost over US$600 thousand.