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Title: Afterslip Enhanced Aftershock Activity During the 2017 Earthquake Sequence Near Sulphur Peak, Idaho

Abstract

An energetic earthquake sequence occurred during September to October 2017 near Sulphur Peak, Idaho. The normal–faulting M w 5.3 mainshock of 2 September 2017 was widely felt in Idaho, Utah, and Wyoming. Over 1,000 aftershocks were located within the first 2 months, 29 of which had magnitudes ≥4.0 M L. High–accuracy locations derived with data from a temporary seismic array show that the sequence occurred in the upper (<10 km) crust of the Aspen Range, east of the northern section of the range–bounding, west–dipping East Bear Lake Fault. Moment tensors for 77 of the largest events show normal and strike–slip faulting with a summed aftershock moment that is 1.8–2.4 times larger than the mainshock moment. Here, we propose that the unusually high productivity of the 2017 Sulphur Peak sequence can be explained by aseismic afterslip, which triggered a secondary swarm south of the coseismic rupture zone beginning ~1 day after the mainshock.

Authors:
ORCiD logo [1]; ORCiD logo [1]; ORCiD logo [1]; ORCiD logo [1];  [1]; ORCiD logo [2]; ORCiD logo [2];  [3]; ORCiD logo [4]; ORCiD logo [5]
  1. Univ. of Utah, Salt Lake City, UT (United States)
  2. U.S. Geological Survey, Denver, CO (United States)
  3. Saint Louis Univ., St. Louis, MO (United States)
  4. Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
  5. Univ. of California San Diego, La Jolla, CA (United States)
Publication Date:
Research Org.:
Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
Sponsoring Org.:
Universities/Institutions; USDOE
OSTI Identifier:
1440499
Report Number(s):
LA-UR-18-22721
Journal ID: ISSN 0094-8276
Grant/Contract Number:
AC52-06NA25396
Resource Type:
Journal Article: Accepted Manuscript
Journal Name:
Geophysical Research Letters
Additional Journal Information:
Journal Name: Geophysical Research Letters; Journal ID: ISSN 0094-8276
Publisher:
American Geophysical Union
Country of Publication:
United States
Language:
English
Subject:
58 GEOSCIENCES; Earth Sciences; earthquake seismology; seismic hazard; aftershocks

Citation Formats

Koper, Keith D., Pankow, Kristine L., Pechmann, James C., Hale, J. Mark, Burlacu, Relu, Yeck, William L., Benz, Harley M., Herrmann, Robert B., Trugman, Daniel Taylor, and Shearer, Peter M.. Afterslip Enhanced Aftershock Activity During the 2017 Earthquake Sequence Near Sulphur Peak, Idaho. United States: N. p., 2018. Web. doi:10.1029/2018GL078196.
Koper, Keith D., Pankow, Kristine L., Pechmann, James C., Hale, J. Mark, Burlacu, Relu, Yeck, William L., Benz, Harley M., Herrmann, Robert B., Trugman, Daniel Taylor, & Shearer, Peter M.. Afterslip Enhanced Aftershock Activity During the 2017 Earthquake Sequence Near Sulphur Peak, Idaho. United States. doi:10.1029/2018GL078196.
Koper, Keith D., Pankow, Kristine L., Pechmann, James C., Hale, J. Mark, Burlacu, Relu, Yeck, William L., Benz, Harley M., Herrmann, Robert B., Trugman, Daniel Taylor, and Shearer, Peter M.. Tue . "Afterslip Enhanced Aftershock Activity During the 2017 Earthquake Sequence Near Sulphur Peak, Idaho". United States. doi:10.1029/2018GL078196.
@article{osti_1440499,
title = {Afterslip Enhanced Aftershock Activity During the 2017 Earthquake Sequence Near Sulphur Peak, Idaho},
author = {Koper, Keith D. and Pankow, Kristine L. and Pechmann, James C. and Hale, J. Mark and Burlacu, Relu and Yeck, William L. and Benz, Harley M. and Herrmann, Robert B. and Trugman, Daniel Taylor and Shearer, Peter M.},
abstractNote = {An energetic earthquake sequence occurred during September to October 2017 near Sulphur Peak, Idaho. The normal–faulting Mw 5.3 mainshock of 2 September 2017 was widely felt in Idaho, Utah, and Wyoming. Over 1,000 aftershocks were located within the first 2 months, 29 of which had magnitudes ≥4.0 ML. High–accuracy locations derived with data from a temporary seismic array show that the sequence occurred in the upper (<10 km) crust of the Aspen Range, east of the northern section of the range–bounding, west–dipping East Bear Lake Fault. Moment tensors for 77 of the largest events show normal and strike–slip faulting with a summed aftershock moment that is 1.8–2.4 times larger than the mainshock moment. Here, we propose that the unusually high productivity of the 2017 Sulphur Peak sequence can be explained by aseismic afterslip, which triggered a secondary swarm south of the coseismic rupture zone beginning ~1 day after the mainshock.},
doi = {10.1029/2018GL078196},
journal = {Geophysical Research Letters},
number = ,
volume = ,
place = {United States},
year = {Tue May 29 00:00:00 EDT 2018},
month = {Tue May 29 00:00:00 EDT 2018}
}

Journal Article:
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