Note: there are a lot of linked PDFs in this diary today. While I recommend that you read them all, they may slow down your browser.
Californians are of course aware of the Field Act. This legislation, the first of its kind in the United States, mandated that schools be resistant to earthquake shaking. It was passed in 1933 in the wake of a moderate but highly damaging and deadly earthquake.
The earthquake struck in the early evening, on March 10th of that year. The Mw 6.4 earthquake’s epicenter was actually closer offshore of Huntington Beach along the Newport-Inglewood fault but the quake’s fury was vented on the city of Long Beach, where ground conditions amplified the shaking. Schools that just a couple hours earlier were full of children crumbled into rubble, 230 in total. Despite the hour, over 100 people died, many because they ran out of buildings and were struck by falling masonry. It remains the deadliest earthquake in Southern California to date. The Field Act was passed just a month later.
The quake itself was one of four damaging quakes that’d rattled the Los Angeles basin starting in 1920.
Also at the same time? Los Angeles was home to the most productive oil fields in the world at the time, something people who don’t live there (or don’t study geology) probably don’t know at all. Some of these oil fields are still active. There were far fewer rules on drilling then. It really was very much like the movie “There Will Be Blood.” Whole areas of the basin subsided. Dr. Susan Hough describes in a Los Angeles Times article:
“It was kind of more of a Wild West industry back a hundred years ago, and the technology wasn’t as sophisticated,” Hough said. “People would just pump oil, and in some cases the ground would subside — fairly dramatically.” That possibly changed stresses on underground rock that could have pushed earthquake faults to rupture.
Fast forward to now, where oil recovery processes such as wastewater injection and hydraulic fracking are responsible for thousands of earthquakes in Oklahoma, southern Kansas, and parts of Texas (and Arkansas, Ohio, and the border region between Colorado and New Mexico to a lesser extent). One happened just this morning, between Stillwater and Tulsa. Now which quakes are natural and which are not, and whether the region centered on Oklahoma was primed and ready to pop is extremely complicated, but the whole ball was set into motion by Drill, baby, Drill getting their way starting in 2009. That, right there, is fact. There are a number of y’all here on the Dkos who argue the US’s energy policy is wise. It certainly is true the US’s use of foreign oil is significantly down since 2009. That decline in imports is almost certainly directly related to the rise in earthquakes in the central US, end of story. There’s no free lunch, folks.
Multiple reanalysis of seismicity for parts of Texas and Oklahoma suggest humans, through oil drilling and recovery, have been inducing earthquakes for a century. In Oklahoma for example, I suspect one would have to go all the way back to 1882 to find a sizeable earthquake that was not induced and/or triggered by oil extraction activities. A new study published this week in the Bulletin of the Seismological Society of America suggests the same thing may be true for a time period in the Los Angeles Basin between 1915 and 1932. Prior studies suggest after 1935 this is not the case, as industry standards changed and the oil industry in California declined. The current study makes this very clear. Now, Los Angeles’s earthquake problem is plate tectonics, but for a period in the past? Perhaps people enhanced it. (I’ll note here that elsewhere in California, science suggest this is still a problem.)
The study, by Dr. Susan Hough and Dr. Morgan Page of the USGS[1], uses historical sleuthing through oil company records to look for associations between drilling sites and earthquake epicenters in the Los Angeles basin. Oil company records sleuthing is a common thing in the LA area. Most, if not all of the blind thrust faults that underlie the basin that have not revealed themselves via an earthquake are known this way.
Recent studies have presented evidence that early to mid‐twentieth‐century earthquakes in Oklahoma and Texas were likely induced by fossil fuel production and/or injection of wastewater (Hough and Page, 2015; Frohlich et al., 2016). Considering seismicity from 1935 onward, Hauksson et al. (2015) concluded that there is no evidence for significant induced activity in the greater Los Angeles region between 1935 and the present. To explore a possible association between earthquakes prior to 1935 and oil and gas production, we first revisit the historical catalog and then review contemporary oil industry activities. Although early industry activities did not induce large numbers of earthquakes, we present evidence for an association between the initial oil boom in the greater Los Angeles area and earthquakes between 1915 and 1932, including the damaging 22 June 1920 Inglewood and 8 July 1929 Whittier earthquakes. We further consider whether the 1933 Mw 6.4 Long Beach earthquake might have been induced, and show some evidence that points to a causative relationship between the earthquake and activities in the Huntington Beach oil field. The hypothesis that the Long Beach earthquake was either induced or triggered by an foreshock cannot be ruled out. Our results suggest that significant earthquakes in southern California during the early twentieth century might have been associated with industry practices that are no longer employed (i.e., production without water reinjection), and do not necessarily imply a high likelihood of induced earthquakes at the present time.
Very interesting, eh?
Some implications (some of which I’ve touched on in previous diaries)
In addition, one thing the study suggests is perhaps the LA Basin, as a geological unit, is a bit more stable than what we currently think, if the series of earthquakes from 1920 to 1935 were triggered and/or induced by oil drilling.
If one wants my personal opinion? I’d say we have enough data. We know how to make earthquakes and under certain conditions, it’s pretty darn easy. I don’t think we need to wait to see if the “experiment” creates something larger than Mw 6. States have chosen to either ignore the problem or put Band-Aids on it. New York state is one of the few who banned it outright and good for them, as I wonder if conditions in parts of that state are just about right (scroll to page 15), like they apparently are under Oklahoma.
Lastly, as Dr. Hough also noted on her twitter account, there’s a great irony in that the oil industry is possibly directly responsible for the Field Act. My inner cynic is having a good cackle.