The USGS’ William Ellsworth has posted an abstract of a talk he and colleagues will give next week. The paper states there has been a surge of earthquakes in the 3.0 range between Alabama and Montana “that is almost certainly man-made”, although they cannot be directly connected to fracking wastewater well operations (UIC for underground injection control):
Are Seismicity Rate Changes in the Midcontinent Natural or Manmade? by W.L. Ellsworth, et al. To be presented at the annual meeting of the Seismological Society of America
http://bit.ly/HsexbB
Also — a research scientist at the Center for Earthquake Research and Information at the University of Memphis has published a paper saying injection was the cause of a cluster of hundreds of minor earthquakes in Arkansas:
Disposal of Hydrofracking Waste Fluid by Injection into Subsurface Aquifers Triggers Earthquake Swarm in Central Arkansas with Potential for Damaging Earthquake, by S. Horton — Seismological Research Letters, March-April 2012, v. 83 no. 2 p. 250-260 http://srl.geoscienceworld.org/content/83/2/250.extract
[PPT summary version: http://bit.ly/H4gfj0 ]
Also — the Ohio DNR finds that the Youngstown New Year’s Eve earthquake was caused by UIC disposal into a “previously unknown” fault:
Preliminary Report on the Northstar 1 Class II Injection Well and the Seismic Events in the Youngstown, Ohio Area Ohio Department of Natural Resources, March 2012 http://ohiodnr.com/downloads/northstar/UICReport.pdf
Also — information on the activities of the EPA’s UIC investigation team, formally known as the Underground Injection Control National Technical Workgroup, who develop guidances and best practices to assist state regulators of UIC operations:
Update on the UIC National Technical Workgroup Injection Induced Seismicity Project, presented by Susie McKenzie EPA Region 6, January 2012
http://bit.ly/I6b0Cc
Also — statement of Interior Department Deputy Secretary, David Hayes on the recent flurry of minor earthquakes across the middle US from the DOI blog, April 11, 2012:
Is the Recent Increase in Felt Earthquakes in the Central US Natural or Manmade? [H/T: E&E News, sub. req'd]
