This Month In Cal OES History: 1983 Coalinga Earthquake

Coalinga, a small city in Fresno County with a population of about 16,000, was rattled by a damaging earthquake 33 years ago this month. Occurring at 4:42 p.m. on May 2, 1983, the shock was felt from the greater Los Angeles area, north to Lassen County in Susanville, and into western Nevada.

A 6.4 magnitude, according to the United States Geological Survey (USGS), the earthquake was caused by an undetected fault under the surface. For two subsequent months following the earthquake, more than 5,000 aftershocks were recorded, with as many as 894 with a magnitude of 2.5 or larger and with the majority occurring in Coalinga.

Though no deaths were reported, the American Red Cross confirmed 94 were injured. The California Governor’s Office of Emergency Services (Cal OES) released a preliminary estimate of property damage at $31 million.

A team of four structural engineers from the Structural Safety Section of the Office of the State Architect (SSS/OSA), at the request of Cal OES, arrived in Coalinga the next morning to make rapid estimates of damage to public schools, gas, water and sewer systems, city hall, fire station, hospital and city, county and state corporation yards.

Coalinga was leveled with the most damage, including almost completely destroying its 8-block downtown commercial district. Most public buildings, such as schools and the city’s hospital, sustained minor damage.

“It was the turning point in the history of this community,” said Coalinga historian Glenn Mitchell on The Valley Today, a reflective show about the earthquake posted to YouTube in 2014.

More than 300 single-family houses and 33 apartment buildings were destroyed, while 558 single-family houses, 94 mobile homes and 39 apartment buildings had major damage. Minor damage was reported on 811 single-family houses, 22 mobile homes and 70 apartment buildings.

Only six of the 60 bridges surveyed had measurable structural damage.

“The miracle of Coalinga is that there were no outright deaths associated with that event,” Mitchell said. “And if you know anything about earthquakes in the news, death is the rule not the exception.”

Coalinga, though, is accustomed to earthquake risks. Since 1931, the USGS database indicates that at least 2,700 earthquakes have occurred in Coalinga and neighboring cities. The 1983 earthquake still remains the largest magnitude to hit the area.

Earlier this month, a shallow magnitude 3.5 earthquake was reported on May 17, about 14 miles from Coalinga. The temblor occurred at 3:58 p.m. at a depth of 4.3 miles. The epicenter was 21 miles from Avenal, 24 miles from Paso Robles, and 33 miles from Atascadero.

Just last year, a 4.2 magnitude earthquake was recorded about 6 miles north of Coalinga.

“The government of Coalinga bet on ourselves. They said we can fix this, we can come back better than ever,” said Mitchell of how the city recovered from the 1983 earthquake. “They rolled the dice. People elected to stay in town and rebuilt the city, and I would argue bigger and better than before.”

Click here to learn about being prepared for earthquakes. Additional information on earthquake, tsunami and volcano programs, as well as the California Earthquake Early Warning System, can also be accessed here.

Jonathan Gudel

Jonathan Gudel is a Public Information Officer for the California Governor's Office of Emergency Services (Cal OES). Since joining Cal OES, he has assisted in the response and recovery efforts of the Aliso Canyon Gas Leak, the state's historic drought, the Oroville Dam Emergency Spillway Incident, unprecedented winter storms in 2017, the October (Sonoma County) and December (Santa Barbara County) 2017 wildfires, and statewide wildfire siege in 2018 . Previously, he worked in the newspaper industry for 12 years.

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