Date | July 29, 2008 |
---|---|
Origin time | 11:42:15 a.m. PDT |
Magnitude | 5.5 Mw |
Depth | 9.1 miles (14.6 km) |
Epicenter | 33°57′11″N 117°45′40″W / 33.953°N 117.761°WCoordinates: 33°57′11″N 117°45′40″W / 33.953°N 117.761°W |
Type | Oblique-slip |
Areas affected |
Greater Los Angeles Area Southern California United States |
Total damage | Limited |
Max. intensity | VI (Strong) |
Peak acceleration | .44g |
Aftershocks | ~100 |
Casualties | 8 injured |
The 2008 Chino Hills earthquake occurred at 11:42:15 a.m. PDT on July 29 in Southern California. The epicenter of the magnitude 5.5 earthquake was in Chino Hills, c. 28 miles (45 km) east-southeast of downtown Los Angeles. Though no lives were lost, eight people were injured, and it caused considerable damage in numerous structures throughout the area and caused some amusement park facilities to shut down their rides. The earthquake led to increased discussion regarding the possibility of a stronger earthquake in the future.
The Chino Hills earthquake was caused by oblique-slip faulting, with components of both thrust and sinistral strike-slip displacement. Preliminary reports cited the Whittier fault as the active cause, but the quake was later determined to have been generated by the "Yorba Linda trend," as identified by Caltech seismologist Egill Hauksson. Its epicenter was within 3 miles (4.8 km) of Chino Hills and its hypocenter was c. 9.1 miles (14.6 km) deep. Initial estimations of the moderate main shock reported it as magnitude 5.8, but this was later revised to magnitude 5.4 and in later months to a 5.5. The main shock was reportedly felt as far south as San Diego, and Tijuana, Mexico, and as far east as Las Vegas, Nevada. It was the strongest earthquake to occur in the greater Los Angeles area since the 1994 Northridge earthquake.