eprintid: 1480 rev_number: 18 eprint_status: archive userid: 2 dir: disk0/00/00/14/80 datestamp: 2015-02-24 11:37:09 lastmod: 2018-03-28 12:17:52 status_changed: 2015-04-27 12:10:58 type: article metadata_visibility: show creators_name: Kilb, Debi creators_name: Gomberg, Joan creators_name: Bodin, Paul corp_creators: Center for Earthquake Research and Information, University of Memphis, Memphis, Tennessee, USA corp_creators: U.S. Geological Survey, Center for Earthquake Research and Information, Memphis, Tennessee, USA corp_creators: Center for Earthquake Research and Information, University of Memphis, Memphis, Tennessee, USA title: Aftershock triggering by complete Coulomb stress changes ispublished: pub subjects: MP6 subjects: RU1 divisions: EPOS-P divisions: EPOS-IP full_text_status: none abstract: We examine the correlation between seismicity rate change following the 1992, M7.3, Landers, California, earthquake and characteristics of the complete Coulomb failure stress (CFS) changes (ΔCFS(t)) that this earthquake generated. At close distances the time-varying “dynamic” portion of the stress change depends on how the rupture develops temporally and spatially and arises from radiated seismic waves and from permanent coseismic fault displacement. The permanent “static” portion (ΔCFS) depends only on the final coseismic displacement. ΔCFS diminishes much more rapidly with distance than the transient, dynamic stress changes. A common interpretation of the strong correlation between ΔCFS and aftershocks is that load changes can advance or delay failure. Stress changes may also promote failure by physically altering properties of the fault or its environs. Because it is transient, ΔCFS(t) can alter the failure rate only by the latter means. We calculate both ΔCFS and the maximum positive value of ΔCFS(t) (peak ΔCFS(t)) using a reflectivity program. Input parameters are constrained by modeling Landers displacement seismograms. We quantify the correlation between maps of seismicity rate changes and maps of modeled ΔCFS and peak ΔCFS(t) and find agreement for both models. However, rupture directivity, which does not affect ΔCFS, creates larger peak ΔCFS(t) values northwest of the main shock. This asymmetry is also observed in seismicity rate changes but not in ΔCFS. This result implies that dynamic stress changes are as effective as static stress changes in triggering aftershocks and may trigger earthquakes long after the waves have passed. date: 2002-04-11 date_type: published publication: Journal of Geophysical Research volume: 107 number: B4 publisher: American Geophysical Union pagerange: 1-14 id_number: doi:10.1029/2001JB000202 refereed: TRUE issn: 0148-0227 official_url: http://dx.doi.org/10.1029/2001JB000202 access_IS-EPOS: limited software_references: Fracture_Network_Models-Mechanical_Stresses owner: Publisher citation: Kilb, Debi and Gomberg, Joan and Bodin, Paul (2002) Aftershock triggering by complete Coulomb stress changes. Journal of Geophysical Research, 107 (B4). pp. 1-14. DOI: https://doi.org/10.1029/2001JB000202