1952 Kern County earthquake

1952 Kern County earthquake
1952 Kern County earthquake is located in California
Chico
Chico
San Francisco
San Francisco
Sacramento
Sacramento
Hawthorne
Hawthorne
Moapa
Moapa
Ridgecrest
Ridgecrest
Indio
Indio
Fresno
Fresno
Lone Pine
Lone Pine
Monterey
Monterey
Parkfield
Parkfield
Bakersfield
Bakersfield
Santa Maria
Santa Maria
Barstow
Barstow
Needles
Needles
Long Beach
Long Beach
San Diego
San Diego
1952 Kern County earthquake
UTC time1952-07-21 11:52:16
ISC event893168
USGS-ANSSComCat
Local dateJuly 21, 1952 (1952-07-21)
Local time4:52 am PDT
Duration7.5 seconds (at Taft)[1]
MagnitudeMw 7.3[2] Ms 7.5[3]
Depth16 km (9.9 mi)[4]
Epicenter34°52′N 119°06′W / 34.86°N 119.10°W / 34.86; -119.10[3]
FaultWhite Wolf Fault
TypeOblique-slip
Areas affectedSouthern California
United States
Total damage$70 million[5][6]
Max. intensityMMI XI (Extreme)[4]
Peak acceleration~ 1.0 g (est)[7]
Casualties14 killed[5][6]
Hundreds injured[5]

The 1952 Kern County earthquake occurred on July 21 in the southern San Joaquin Valley and measured 7.3 on the moment magnitude scale. The main shock occurred at 4:52 am Pacific Daylight Time (11:52 UTC), killed 12 people, injured hundreds more and caused an estimated $60 million in property damage. A small sector of damage near Bealville corresponded to a maximum Mercalli intensity of XI (Extreme), though this intensity rating was not representative of the majority of damage. The earthquake occurred on the White Wolf Fault near the community of Wheeler Ridge and was the strongest to occur in California since the 1906 San Francisco earthquake.

The town of Tehachapi suffered the greatest damage and loss of life from the earthquake, though other locations in Kern County experienced significant damage as well, but its effects were widely felt throughout central and southern California. The July mainshock had a significant aftershock sequence that persisted into July and August with many magnitude 5+ events with intensities of V (Moderate) to VII (Very strong). Six of these aftershocks occurred on the day of the mainshock, but the strongest aftershock came on August 22 as a M5.8 event that had a maximum perceived intensity of VIII (Severe) and resulted in the deaths of two people and caused an additional $10 million in property damage.

Following the event, a field survey was conducted along the fault zone with the goal of estimating the peak ground acceleration of the shock based on visually evaluating precarious rock formations and other indicators. Ground disturbances that were created by the earthquakes were also surveyed, both in the valley and in the foothills, with both vertical and horizontal displacements present in the epicentral area. The strong motion records that were acquired from the event were significant, and a reconnaissance report was recognized for its coverage of the event, and how it set a standard for those types of engineering or scientific papers. Repercussions of the sequence of earthquakes were still being felt in the heavily damaged downtown area of Bakersfield well into the 1990s as city leaders attempted to improve safety of the surviving unreinforced masonry buildings.

  1. ^ Cite error: The named reference Gutenberg-Richter was invoked but never defined (see the help page).
  2. ^ Cite error: The named reference Bawden was invoked but never defined (see the help page).
  3. ^ a b ISC-OB Event 893168 [IRIS].
  4. ^ a b Stover & Coffman 1993, p. 86
  5. ^ a b c Cite error: The named reference PAGER-CAT was invoked but never defined (see the help page).
  6. ^ a b Cite error: The named reference Stover_p144 was invoked but never defined (see the help page).
  7. ^ Brune et al. 2004, p. 2002