An improved framework for discriminating seismicity induced by industrial activities from natural earthquakes
File(s)Verdon et al_2019_Accepted.pdf (1.89 MB)
Accepted version
Author(s)
Verdon, James P
Baptie, Brian J
Bommer, Julian
Type
Journal Article
Abstract
Heightened concerns regarding induced seismicity necessitate robust methods to assess whether detected earthquakes near industrial sites are natural or induced by the industrial activity. These assessments are required rapidly, which often precludes detailed modeling of fluid pressures and the geomechanical response of the reservoir and nearby faults. Simple question‐based assessment schemes in current use are a useful tool but suffer from several shortcomings: they do not specifically address questions regarding whether available evidence supports the case for natural seismicity; they give all questions equal weighting regardless of the relative influence of different factors; they are not formulated to account for ambiguous or uncertain evidence; and the final outcomes can be difficult to interpret. We propose a new framework that addresses these shortcomings by assigning numerical scores to each question, with positive values for answers that support induced seismicity and negative values for responses favoring natural seismicity. The score values available for each question reflect the relative importance of the different questions, and for each question the absolute value of the score is modulated according to the degree of uncertainty. The final outcome is a score, the induced assessment ratio, either positive or negative (or zero), that reflects whether events were induced or natural. A second score, the evidence strength ratio, is assigned that characterizes the strength of the available evidence, expressed as the ratio of the maximum score possible with the available evidence relative to the maximum score that could be obtained if all desired data were available at a site. We demonstrate this approach by application to two case studies in the United Kingdom, one widely regarded as a case of induced seismicity, and the other more likely to be a series of tectonic earthquakes.
Date Issued
2019-04-17
Date Acceptance
2019-03-20
Citation
Seismological Research Letters, 2019, 90 (4), pp.1592-1611
ISSN
0895-0695
Publisher
Seismological Society of America
Start Page
1592
End Page
1611
Journal / Book Title
Seismological Research Letters
Volume
90
Issue
4
Copyright Statement
© Seismological Society of America
Subjects
Science & Technology
Physical Sciences
Geochemistry & Geophysics
MOMENT TENSOR INVERSION
PROBABILISTIC APPROACH
CLIFF FROHLICH
HEATHER DESHON
MATT HORNBACH
CHRIS HAYWARD
BRIAN STUMP
INJECTION
TEXAS
OKLAHOMA
Geochemistry & Geophysics
0404 Geophysics
Publication Status
Published
Date Publish Online
2019-07-10