ISTI is pleased to announce a publication of Maturity of nearby faults influences seismic hazard from hydraulic fracturing, a collaboration between ISTI and our colleagues in the field. The article was published by the National Academy of Sciences on 5 February 2018. ISTI wishes to recognize the authors:
- Maria Kozłowska – Department of Geology and Environmental Earth Science, Miami University, Oxford, OH
- Michael R. Brudzinski – Department of Geology and Environmental Earth Science, Miami University, Oxford, OH
- Paul Friberg – (ISTI) Instrumental Software Technologies, Inc.
- Robert J. Skoumal – Earthquake Science Center, US Geological Survey
- Nicholas D. Baxter – Department of Geology and Environmental Earth Science, Miami University, Oxford, OH
- Brian S. Currie – Department of Geology and Environmental Earth Science, Miami University, Oxford, OH
Recent studies have focused on how wastewater disposal wells have caused dramatic increases in eastern US earthquakes. We focused instead on less common cases where hydraulic fracturing alone has caused earthquakes and found seismicity separated into two depth zones: a shallow zone on younger faults, with more small-magnitude earthquakes than expected, and a deeper zone on older faults, with larger magnitude earthquakes and seismicity continuing after fracturing stops. Hence, inducing deeper seismicity creates more hazard. Our observations are consistent with prior geologic, laboratory, and theoretical work indicating that age and maturity of faults causes the different seismicity patterns. We utilize data from well operators to demonstrate that both fluid pressure changes and rock stress transfer are needed to explain our observations.
Understanding the causes of human-induced earthquakes is paramount to reducing societal risk. We investigated five cases of seismicity associated with hydraulic fracturing (HF) in Ohio since 2013 that, because of their isolation from other injection activities, provide an ideal setting for studying the relations between high-pressure injection and earthquakes. Our analysis revealed two distinct groups: continue reading.