There have been some recent earthquakes in and around the Inglewood Oil Field, but we have been assured that they are not linked to drilling, fracking, water-injection or any other thing that the operator might have done or is doing. This is, probably, the case. I mean, it's not like earthquakes are unknown in Southern California. My gut tells me it's something like climate change. You can't blame climate change for *that* hot day, but climate change is making hot days occur more frequently. You can't blame water injection for *that* earthquake, but it has made earthquakes in general more frequent. And it might be that it actually hasn't changed the frequency at all. But let's look at the reasoning given in the article:
Hypothesis: "A typical human induced earthquake is shallow -- about a mile below the surface," but the recent quakes have been deeper than that, and therefore cannot be human induced.
Now, Oklahoma has seen a 60,000% increase in earthquakes, and has stated that this "cannot be entirely attributed to natural causes" and is "very likely triggered by the injection of produced water in disposal wells."
Prediction: Now, if typical human-induced earthquakes are shallow (about a mile) then most Oklahoma earthquakes should be only 1 or 2 kilometers deep.
Data: Today's Earthquakes for Oklahoma.
Analysis: Hardly any of them are only as shallow as 'a mile'. And if you scroll back, there are few that break 10 km, on par with the 6 or 7 mile depth of the Baldwin Hills quakes.
Conclusion: The unnamed seismologists who say typical human induced quakes are only a mile deep are full of shit. (or my geological ignorance has made me the shit-filled one)
[I considered that one difference might be, maybe Oklahoma wells inject deeper, and that's why the earthquakes are deeper, but figure 13 of this report (p.24) shows that the median well depth is "about a mile", and the deepest injection well in the state is 18,886 ft (5.75 km) (p.7). Median earthquake depth (p.9) was 3.75 km. Fracking in the Inglewood Oil Field apparently reached "a depth of about one and half miles".]