Greeley the new Oklahoma?
A M3.4 earthquake in Greeley, Colorado is pretty suspicious. The news report has the odd sentence
Earle [of the USGS] said earthquakes like this have been caused by underground disposal of fracking waste water, but it is far too early to determine if that was even going on in the area of the earthquake.
Um, this actually isn’t so hard to determine (one wonders if anybody looks at the Colorado Oil and Gas Commission databases to at least know where there are disposal wells). The answer is yes, there are disposal wells in the vicinity, and given the history of the region, the previous experiences with deep injection producing earthquakes in the Front Range of Colorado (see below), the odds are quite high that this was indeed induced by deep injection of production (used in fracking) water….but at present the location is pretty poor and you’d like to see the injection histories of nearby wells…
Update: the Greeley paper ran a story on a quick RAMP (Rapid Array Mobilization Program, otherwise known as Run Around with Much Panic) deployment of seismometers run out of CU Boulder to better locate earthquakes in the area (the locations reported of the 3.4 used stations no closer than 70 km away). They followed that up with an unusually comprehensive story about wastewater disposal.