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Coevolving early afterslip and aftershock signatures of a San Andreas fault rupture

Large earthquakes often lead to transient deformation and enhanced seismic activity, with their fastest evolution occurring at the early, ephemeral post-rupture period. Here, we investigate this elusive phase using geophysical observations from the 2004 moment magnitude 6.0 Parkfield, California, ea...

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Detalles Bibliográficos
Autores principales: Jiang, Junle, Bock, Yehuda, Klein, Emilie
Formato: Online Artículo Texto
Lenguaje:English
Publicado: American Association for the Advancement of Science 2021
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8034852/
https://www.ncbi.nlm.nih.gov/pubmed/33837071
http://dx.doi.org/10.1126/sciadv.abc1606
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author Jiang, Junle
Bock, Yehuda
Klein, Emilie
author_facet Jiang, Junle
Bock, Yehuda
Klein, Emilie
author_sort Jiang, Junle
collection PubMed
description Large earthquakes often lead to transient deformation and enhanced seismic activity, with their fastest evolution occurring at the early, ephemeral post-rupture period. Here, we investigate this elusive phase using geophysical observations from the 2004 moment magnitude 6.0 Parkfield, California, earthquake. We image continuously evolving afterslip, along with aftershocks, on the San Andreas fault over a minutes-to-days postseismic time span. Our results reveal a multistage scenario, including immediate onset of afterslip following tens-of-seconds-long coseismic shaking, short-lived slip reversals within minutes, expanding afterslip within hours, and slip migration between subparallel fault strands within days. The early afterslip and associated stress changes appear synchronized with local aftershock rates, with increasing afterslip often preceding larger aftershocks, suggesting the control of afterslip on fine-scale aftershock behavior. We interpret complex shallow processes as dynamic signatures of a three-dimensional fault-zone structure. These findings highlight important roles of aseismic source processes and structural factors in seismicity evolution, offering potential prospects for improving aftershock forecasts.
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spelling pubmed-80348522021-04-21 Coevolving early afterslip and aftershock signatures of a San Andreas fault rupture Jiang, Junle Bock, Yehuda Klein, Emilie Sci Adv Research Articles Large earthquakes often lead to transient deformation and enhanced seismic activity, with their fastest evolution occurring at the early, ephemeral post-rupture period. Here, we investigate this elusive phase using geophysical observations from the 2004 moment magnitude 6.0 Parkfield, California, earthquake. We image continuously evolving afterslip, along with aftershocks, on the San Andreas fault over a minutes-to-days postseismic time span. Our results reveal a multistage scenario, including immediate onset of afterslip following tens-of-seconds-long coseismic shaking, short-lived slip reversals within minutes, expanding afterslip within hours, and slip migration between subparallel fault strands within days. The early afterslip and associated stress changes appear synchronized with local aftershock rates, with increasing afterslip often preceding larger aftershocks, suggesting the control of afterslip on fine-scale aftershock behavior. We interpret complex shallow processes as dynamic signatures of a three-dimensional fault-zone structure. These findings highlight important roles of aseismic source processes and structural factors in seismicity evolution, offering potential prospects for improving aftershock forecasts. American Association for the Advancement of Science 2021-04-09 /pmc/articles/PMC8034852/ /pubmed/33837071 http://dx.doi.org/10.1126/sciadv.abc1606 Text en Copyright © 2021 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works. Distributed under a Creative Commons Attribution NonCommercial License 4.0 (CC BY-NC). https://creativecommons.org/licenses/by-nc/4.0/This is an open-access article distributed under the terms of the Creative Commons Attribution-NonCommercial license (https://creativecommons.org/licenses/by-nc/4.0/) , which permits use, distribution, and reproduction in any medium, so long as the resultant use is not for commercial advantage and provided the original work is properly cited.
spellingShingle Research Articles
Jiang, Junle
Bock, Yehuda
Klein, Emilie
Coevolving early afterslip and aftershock signatures of a San Andreas fault rupture
title Coevolving early afterslip and aftershock signatures of a San Andreas fault rupture
title_full Coevolving early afterslip and aftershock signatures of a San Andreas fault rupture
title_fullStr Coevolving early afterslip and aftershock signatures of a San Andreas fault rupture
title_full_unstemmed Coevolving early afterslip and aftershock signatures of a San Andreas fault rupture
title_short Coevolving early afterslip and aftershock signatures of a San Andreas fault rupture
title_sort coevolving early afterslip and aftershock signatures of a san andreas fault rupture
topic Research Articles
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8034852/
https://www.ncbi.nlm.nih.gov/pubmed/33837071
http://dx.doi.org/10.1126/sciadv.abc1606
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