WAS THE 1952 KERN COUNTY, CALIFORNIA EARTHQUAKE CAUSED BY OIL DRILLING?

The 1952 Kern County,California Earthquake near Bakersfield had a 7.3 magnitude (listed at 7.5 in some references), caused much damage, killed 14 people and injured hundreds. 

Most of Southern and Central California felt the shaking

                     Many pictures of the damage were taken.

But was this earthquake actually triggered accidentally by oil-drilling operations underway on the White Wolf fault in the Tehachapi mountains, as recent studies seem to indicate?

EXCERPT:
                                      "Several recent studies have presented evidence that significant induced earthquakes occurred in a number of oil-producing regions during the early and mid-twentieth century related to either production or wastewater injection. We consider whether the 21 July 1952 Mw 7.5 Kern County earthquake might have been induced by production in the Wheeler Ridge oil field. The mainshock, which was not preceded by any significant foreshocks, occurred 98 days after the initial production of oil in Eocene strata at depths reaching 3 km, within ~1 km of the White Wolf fault (WWF). Based on this spatial and temporal proximity, we explore a potential causal relationship between the earthquake and oil production. While production would have normally be expected to have reduced pore pressure, inhibiting failure on the WWF, we present an analytical model based on industry stratigraphic data and best estimates of parameters whereby an impermeable splay fault adjacent to the main WWF could plausibly have blocked direct pore pressure effects, allowing the poroelastic stress change associated with production to destabilize the WWF, promoting initial failure. This proof-of-concept model can also account for the 98-day delay between the onset of production and the earthquake. While the earthquake clearly released stored tectonic stress, any initial perturbation on or near a major fault system can trigger a larger rupture. Our proposed mechanism provides an explanation for why significant earthquakes are not commonly induced by production in proximity to major faults."

2nd  EXCERPT: 

"The hazard associated with induced earthquakes has come to the fore in recent years with the rise in seismic activity, including events with magnitudes upwards of 4, in areas where there has been an increase in subsurface fluid injection and production operations, including both hydraulic fracturing (Schulz et al. 2015; Atkinson et al. 2016) and injection of large volumes of wastewater (Keranen et al. 2013; Goebel et al. 2015; Walsh and Zoback 2015; Weingarten et al. 2015). While the association between earthquakes and wastewater injection was established in the late 1960s (Evans 1966), and a small number of published studies in the twentieth century identified potentially induced events associated with fossil fuel production (Caloi et al. 1956; Kovach 1974; Simpson and Leith 1985; Nicholson and Wesson 1990), the level of hazard associated with induced earthquakes has only in recent years been evaluated (Petersen et al. 2016). Several recent studies have presented evidence suggesting that oil and gas production and/or wastewater injection may have caused damaging induced events as early as the early- to mid-twentieth century (Hough and Page 2015; Frohlich et al. 2016; Hough and Page 2016). In this paper, we explore the possibility that the 1952 Kern County, California, earthquake, estimated magnitude 7.3–7.7, might have been induced by oil production in the Wheeler Ridge oil field. We first review the history of oil production in this field; we then discuss the earthquake and its possible association with production."

Final statement:

"Although we cannot rule out the possibility that the 1952 earthquake was purely tectonic in origin, the proximity of the rupture zone for this event to the producing reservoir and the short time lapse between onset of deep production and the occurrence of the 1952 earthquake (98 days) supports the hypothesis that this event was triggered by stress changes associated with oil production."

Excerpts are from:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5693966/

LINKS:

WAS THE 1952 KERN COUNTY EARTHQUAKE INDUCED OR TRIGGERED?


1952 Kern County Earthquake



Other, more recent quakes may have been triggered by oil-drilling as well: 


Kern oil field injections suspected of causing series of 2005 quakes


Study: Oil field operations caused California earthquakes (in 2005)