How large are the earthquakes induced by fluid injection?

The largest earthquake induced by fluid injection that has been documented in the scientific literature was the November 6, 2011 earthquake in central Oklahoma.  It had a magnitude of 5.6.  Earlier that year, a magnitude 5.3 earthquake was induced by fluid injection in the Raton Basin, Colorado.  Earthquakes with magnitudes between 4.5 and 5.0 have been induced by fluid injection in Arkansas, Colorado, Kansas, Oklahoma, and Texas.

 

*definition of earthquake magnitude