1992 Big Bear earthquake

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1992 Big Bear earthquake
USGS Shakemap - 1992 Big Bear earthquake.jpg
1992 Big Bear earthquake is located in California
Los Angeles
Los Angeles
Palm Springs
Palm Springs
1992 Big Bear earthquake
UTC time1992-06-28 15:05:33
ISC event289115
Local dateJune 28, 1992 (1992-06-28)
Local time08:05:33 PDT
Magnitude6.5 Mw [1]
Depth3.1 miles (5 km) [2]
Epicenter34°17′N 116°49′W / 34.29°N 116.82°W / 34.29; -116.82Coordinates: 34°17′N 116°49′W / 34.29°N 116.82°W / 34.29; -116.82 [2]
TypeStrike-slip [2]
Areas affectedInland Empire
Southern California
United States
Total damageModerate [3]
Max. intensityVIII (Severe) [4]
Foreshocks5.2 Mw June 28 at 14:43 [5]
Aftershocks5.3 Mw  July 9 at 01:43 [5]
5.2 Mw  Nov 27 at 16:00 [5]
5.1 Mw  Dec 4 at 02:08 [5]
CasualtiesSome injuries [4]

The 1992 Big Bear earthquake occurred at 08:05:33 PDT on June 28 in Big Bear Lake, California, with a moment magnitude of 6.5 and a maximum perceived intensity of VIII (Severe) on the Mercalli intensity scale. The earthquake occurred at a relatively shallow depth of 5 kilometers (3.1 mi) and caused landslides in the San Bernardino Mountains.[6]

The Big Bear earthquake happened just east of the "Big Bend" of the San Andreas Fault, where it takes an offset towards Los Angeles, and 3 hours 26 minutes after the M 7.3 1992 Landers earthquake occurred 22 miles (35 km) to the east. The Big Bear earthquake was first believed to be an aftershock of the Landers quake. However, the United States Geological Survey determined that this was a separate, but related, earthquake. These two earthquakes are considered a regional earthquake sequence, rather than a main shock and aftershock. They were part of a complex pattern of regional stress adjustment that also led to the 1999 Hector Mine earthquake.[7]

On that day, proceeding the earthquake an experimental aircraft crashed at the Big Bear Airport. Reenactment and some footage was taped and aired on the CBS TV series Rescue 911

See also[edit]


  1. ^ ISC (January 19, 2015), ISC-GEM Global Instrumental Earthquake Catalogue (1900–2009), Version 2.0, International Seismological Centre
  2. ^ a b c USGS (September 4, 2009), PAGER-CAT Earthquake Catalog, Version 2008_06.1, United States Geological Survey
  3. ^ National Geophysical Data Center / World Data Service (NGDC/WDS) (1972), Significant Earthquake Database (Data Set), National Geophysical Data Center, NOAA, doi:10.7289/V5TD9V7K
  4. ^ a b USGS, M6.5 - Southern California, United States Geological Survey
  5. ^ a b c d Jones, L. E.; Hough, S. E. (1995), "Analysis of broadband records from the 28 June 1992 Big Bear earthquake: Evidence of a multiple-event source", Bulletin of the Seismological Society of America, 85 (3): 690
  6. ^ "Big Bear Earthquake". Southern California Earthquake Center. Retrieved May 23, 2012.
  7. ^ Parsons, Tom; Dreger, Douglas S. (July 1, 2000). "Static-stress impact of the 1992 Landers earthquake sequence on nucleation and slip at the site of the 1999 M=7.1 Hector Mine earthquake, southern California". Geophysical Research Letters. 27 (13): 1949–1952. Bibcode:2000GeoRL..27.1949P. doi:10.1029/1999GL011272.

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