Shaking intensity from injection-induced versus tectonic earthquakes in the central-eastern United States

The Leading Edge
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Abstract

Although instrumental recordings of earthquakes in the central and eastern United States (CEUS) remain sparse, the U. S. Geological Survey's “Did you feel it?” (DYFI) system now provides excellent characterization of shaking intensities caused by induced and tectonic earthquakes. Seventeen CEUS events are considered between 2013 and 2015. It is shown that for 15 events, observed intensities at epicentral distances greater than ≈ 10 km are lower than expected given a published intensity-prediction equation for the region. Using simple published relations among intensity, magnitude, and stress drop, the results suggest that 15 of the 17 events have low stress drop. For those 15 events, intensities within ≈ 10-km epicentral distance are closer to predicted values, which can be explained as a consequence of relatively shallow source depths. The results suggest that those 15 events, most of which occurred in areas where induced earthquakes have occurred previously, were likely induced. Although moderate injection-induced earthquakes in the central and eastern United States will be felt widely because of low regional attenuation, the damage from shallow earthquakes induced by injection will be more localized to event epicenters than shaking tectonic earthquakes, which tend to be somewhat deeper. Within approximately 10 km of the epicenter, intensities are generally commensurate with predicted levels expected for the event magnitude.

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Additional publication details

Publication type Article
Publication Subtype Journal Article
Title Shaking intensity from injection-induced versus tectonic earthquakes in the central-eastern United States
Series title The Leading Edge
DOI 10.1190/tle34060690.1
Volume 34
Issue 6
Year Published 2015
Language English
Publisher Society of Exploration Geophysicists
Contributing office(s) Earthquake Science Center
Description 6 p.
First page 690
Last page 697
Country United States