2014 La Habra earthquake
Damage in Fullerton home
ShakeMap created by the United States Geological Survey for the event
2014 La Habra earthquake is located in California
Los Angeles
Los Angeles
San Diego
San Diego
San Luis Obispo
San Luis Obispo
Bakersfield
Bakersfield
2014 La Habra earthquake
2014 La Habra earthquake (California)
UTC time2014-03-29 04:09:42
ISC event604372955
USGS-ANSSComCat
Local dateMarch 28, 2014 (2014-03-28)
Local time9:09:42 p.m. PDT
Duration12 seconds[1]
Magnitude5.1 Mw[2]
Depth5.1 km (3.2 mi)[2]
Epicenter33°55′59″N 117°54′58″W / 33.933°N 117.916°W / 33.933; -117.916[2]
FaultPuente Hills Fault[1]
TypeOblique Thrust[3]
Areas affectedGreater Los Angeles
Southern California
Total damage$10.8 million [1]
Max. intensityVII (Very strong) [2]
Peak acceleration0.7 g[4]
LandslidesYes[1]
Foreshocks3.6 Mw 2.1 Mw[1]
Aftershocks100+ [5]
Largest: 4.1 Mw [6]
CasualtiesNone

The 2014 La Habra earthquake was a magnitude 5.1 earthquake that occurred on March 28, 2014, at 9:09:42 p.m. PDT. Although given the name "La Habra" it was centered in Brea, a city in northern Orange County.[2] Despite its moderate magnitude, it had a maximum Mercalli intensity of VII (Very strong), and caused a total of $10.8 million in damage.[1][2] Thirteen water mains broke in Fullerton, forcing roughly 70 families to be displaced from their homes after they were declared temporarily uninhabitable.[1]

Tectonic setting

The La Habra earthquake was caused by oblique thrust faulting on the Coyote Hills segment of the Puente Hills Thrust Fault System.[1][3] The Puente Hills Fault is a blind thrust fault that runs north and west from Orange County to Los Angeles. It was the fault that was responsible for the 5.9 Mw 1987 Whittier Narrows earthquake on October 1, 1987.[1] This area was previously shaken by the 5.4 Mw 2008 Chino Hills earthquake, which struck on the Yorba Linda Fault on July 29, 2008.[7] The USGS moment tensor shows that Oblique faulting with a north-dipping plane roughly correlating to the Puente Hills thrust fault system.[1]

Earthquake

The earthquake was the most powerful earthquake in Southern California since the 2008 Chino Hills earthquake which had a moment magnitude of 5.4.[8] Its epicenter was 1 mi (1.6 km) east of La Habra and its hypocenter was 3.2 mi (5.1 km) deep.[2] Initial reports placed the magnitude at 5.3, however it was later downgraded to magnitude 5.1. Although the ShakeMap displays a vast area of highest Mercalli intensity of VI (Strong), the maximum observed Mercalli intensity was VII (Very strong), reported in La Habra, Brea, La Habra Heights, and Rowland Heights. In the area close to the epicenter, the greatest recorded Mercalli intensity for the DYFI map (Did You Feel It?) was VI (Strong). In Pasadena, the earthquake early warning system (ShakeAlert) provided a four-second warning before shaking arrived.[1]

Impact

The earthquake caused no deaths. It was felt as far away as San Diego, Bakersfield, Las Vegas, San Luis Obispo, and Ensenada, Mexico.[9][1] Some Southern California residents reported a temporary power outage.[1] The earthquake sequence resulted in 13 water main breaks, a gas line break, and several pavement fissures. The majority of events occurred within a 6 km (3.7 mi) radius of the epicenter.[3] A street in Brea was blocked after a rockslide forced a car to overturn, causing minor injuries.[1] In La Habra, a Red Cross shelter was established for residents who were forced out of their homes or who opted to stay. Approximately 38 people remained the night, including numerous families. According to residents in Orange County, shaking lasted around 10 seconds. Disneyland temporarily stopped rides as a precaution and some visitors claimed they were stranded on rides.[10][11]

Aftershocks

Over the next few days, there were over a hundred aftershocks, including a magnitude 4.1 earthquake just a few miles distant from the mainshock.[5][6] There were two foreshocks with magnitudes of 3.6 and 2.1 that preceded the main earthquake.[12][1] A relatively shallow aftershock sequence followed the primary shock, spreading upward from a depth of 7 km (4.4 mi) to approximately 3 km (1.9 mi) underneath the municipalities of La Habra, Fullerton, and Brea. One of the focal mechanism solutions, showing mainshock rupture of a northeast striking, northwest dipping left-lateral oblique thrust fault, is compatible with the northeast trend of aftershocks.[3]

See also

References

  1. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 National Geophysical Data Center /World Data Service (NGDC/WDS) (1972), Significant Earthquake Database (Data Set), National Geophysical Data Center, NOAA, doi:10.7289/V5TD9V7K, retrieved November 3, 2021
  2. 1 2 3 4 5 6 7 M 5.1 - 2km NW of Brea, CA, United States Geological Survey, retrieved November 3, 2021
  3. 1 2 3 4 Donnellan, Andrea; Grant Ludwig, Lisa; Parker, Jay W.; Rundle, John B.; Wang, Jun; Pierce, Marlon; Blewitt, Geoffrey; Hensley, Scott (2015), "Potential for a large earthquake near Los Angeles inferred from the 2014 La Habra earthquake", Earth and Space Science, Advancing Earth and Space Science, 2 (9): 378–385, Bibcode:2015E&SS....2..378D, doi:10.1002/2015EA000113, PMC 5125407, PMID 27981074
  4. ↑ Donnellan, Andrea; Grant Ludwig, Lisa; Parker, Jay W.; Rundle, John B.; Wang, Jun; Pierce, Marlon; Blewitt, Geoffrey; Hensley, Scott (2015), "Potential for a large earthquake near Los Angeles inferred from the 2014 La Habra earthquake", Earth and Space Science, NASA, 2 (9): 378–385, Bibcode:2015E&SS....2..378D, doi:10.1002/2015EA000113, PMC 5125407, PMID 27981074, S2CID 793953, retrieved November 3, 2021
  5. 1 2 Five-year anniversary of La Habra earthquake is a reminder to get prepared, California Earthquake Authority, retrieved November 3, 2021
  6. 1 2 M 4.1 - 2km SE of Rowland Heights, CA, United States Geological Survey, retrieved November 3, 2021
  7. ↑ Robbins, Gary (July 31, 2007), "Little known Yorba Linda fault caused Tuesday's quake", The Orange County Register, Orange County Register Communications, archived from the original on August 28, 2008, retrieved November 12, 2021
  8. ↑ M 5.4 - 5km S of Chino Hills, CA - Origin, United States Geological Survey, retrieved November 11, 2021
  9. ↑ M 5.1 - La Habra - Did You Feel It?, United States Geological Survey, retrieved November 3, 2021
  10. ↑ Radio, Southern California Public (March 28, 2014), "5.1 earthquake strikes near La Habra, Calif. (updated)", Southern California Public Radio, retrieved November 17, 2021
  11. ↑ "#LetMeTakeASelfie on Matterhorn after we got stuck from the #earthquake #disneyland", Twitter, March 28, 2014, retrieved November 17, 2021
  12. ↑ M 5.1 - La Habra - Nearby Seismisity, United States Geological Survey, retrieved November 3, 2021
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