Yesterday the journal Science published a pair of papers related to earthquakes that occur near sites where various waste fluids are pumped deep underground. The mainstream news sites tended to make a muddle of these papers, but their upshot is that some patterns are emerging in the relationship between industrial activity and earthquakes.
One paper noted that some injection-well sites responded with little quakes to the seismic waves of very large distant earthquakes (dynamic triggering) in the months before they had earthquake swarms of their own. The idea was that the faults that failed in the swarms were signaling their highly stressed state through their earlier sensitivity to dynamic triggering. It's possible that this pattern could help in managing injection-well fields.
The other paper compared the local earthquake record with the record of steam production in a set of geothermal power plants in southern California and found a linknot with straight steam production but with net fluid production, hot water pumped out minus condensate pumped back. That's a small bit of progress on the larger problem of managing underground processes in highly stressed crust.
More important for public purposes was a third paper, by U.S. Geological Survey seismologist Bill Ellsworth, reviewing the whole topic of injection-induced earthquakeswhat many people persist in thinking of as "fracking quakes." Fracking does not cause this kind of earthquake except in a one-in-a-million sense. These are more like one-in-ten-thousand events that occur in areas where deep injection wells dispose of fluids related to petroleum production in areas that happen to have unmapped faults. Science operates behind a paywall, but the USGS has put up its own condensed version of the paper under the title "Man-Made Earthquakes," and it's good reading.