EARTH - 2011 Oklahoma temblor: Wastewater injection spurred biggest earthquake yet, study says

A new study is the latest to tie a string of unusual earthquakes, in this case, in central Oklahoma, to injection of wastewater underground. Researchers now say that the magnitude 5.7 earthquake near Prague, Okla., on Nov. 6, 2011, may also be the largest ever linked to wastewater injection. Felt more than 800 miles away, the quake -- the biggest ever recorded in Oklahoma -- destroyed 14 homes, buckled a highway and left two people injured. Earthquakes continue to be recorded in the area.

http://www.sciencedaily.com/releases/2013/03/130326151125.ht