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Mechanics of near-field deformation during co- and post-seismic shallow fault slip

Poor knowledge of how faults slip and distribute deformation in the shallow crust hinders efforts to mitigate hazards where faults increasingly intersect with the expanding global population at Earth’s surface. Here we analyze two study sites along the 2014 M 6.0 South Napa, California, earthquake r...

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Autores principales: Nevitt, Johanna M., Brooks, Benjamin A., Catchings, Rufus D., Goldman, Mark R., Ericksen, Todd L., Glennie, Craig L.
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Nature Publishing Group UK 2020
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7081326/
https://www.ncbi.nlm.nih.gov/pubmed/32193474
http://dx.doi.org/10.1038/s41598-020-61400-9
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author Nevitt, Johanna M.
Brooks, Benjamin A.
Catchings, Rufus D.
Goldman, Mark R.
Ericksen, Todd L.
Glennie, Craig L.
author_facet Nevitt, Johanna M.
Brooks, Benjamin A.
Catchings, Rufus D.
Goldman, Mark R.
Ericksen, Todd L.
Glennie, Craig L.
author_sort Nevitt, Johanna M.
collection PubMed
description Poor knowledge of how faults slip and distribute deformation in the shallow crust hinders efforts to mitigate hazards where faults increasingly intersect with the expanding global population at Earth’s surface. Here we analyze two study sites along the 2014 M 6.0 South Napa, California, earthquake rupture, each dominated by either co- or post-seismic shallow fault slip. We combine mobile laser scanning (MLS), active-source seismic tomography, and finite element modeling to investigate how deformation rate and mechanical properties of the shallow crust affect fault behavior. Despite four orders-of-magnitude difference in the rupture velocities, MLS-derived shear strain fields are remarkably similar at the two sites and suggest deceleration of the co-seismic rupture near Earth’s surface. Constrained by the MLS and seismic data, finite element models indicate shallow faulting is more sensitive to lithologic layering and plastic yielding than to the presence of fault compliant zones (i.e., regions surrounding faults with reduced stiffness). Although both elastic and elastoplastic models can reproduce the observed surface displacement fields within the uncertainty of MLS data, elastoplastic models likely provide the most reliable representations of subsurface fault behavior, as they produce geologically reasonable stress states and are consistent with field, geodetic, and seismological observations.
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spelling pubmed-70813262020-03-23 Mechanics of near-field deformation during co- and post-seismic shallow fault slip Nevitt, Johanna M. Brooks, Benjamin A. Catchings, Rufus D. Goldman, Mark R. Ericksen, Todd L. Glennie, Craig L. Sci Rep Article Poor knowledge of how faults slip and distribute deformation in the shallow crust hinders efforts to mitigate hazards where faults increasingly intersect with the expanding global population at Earth’s surface. Here we analyze two study sites along the 2014 M 6.0 South Napa, California, earthquake rupture, each dominated by either co- or post-seismic shallow fault slip. We combine mobile laser scanning (MLS), active-source seismic tomography, and finite element modeling to investigate how deformation rate and mechanical properties of the shallow crust affect fault behavior. Despite four orders-of-magnitude difference in the rupture velocities, MLS-derived shear strain fields are remarkably similar at the two sites and suggest deceleration of the co-seismic rupture near Earth’s surface. Constrained by the MLS and seismic data, finite element models indicate shallow faulting is more sensitive to lithologic layering and plastic yielding than to the presence of fault compliant zones (i.e., regions surrounding faults with reduced stiffness). Although both elastic and elastoplastic models can reproduce the observed surface displacement fields within the uncertainty of MLS data, elastoplastic models likely provide the most reliable representations of subsurface fault behavior, as they produce geologically reasonable stress states and are consistent with field, geodetic, and seismological observations. Nature Publishing Group UK 2020-03-19 /pmc/articles/PMC7081326/ /pubmed/32193474 http://dx.doi.org/10.1038/s41598-020-61400-9 Text en © The Author(s) 2020 Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons license and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/.
spellingShingle Article
Nevitt, Johanna M.
Brooks, Benjamin A.
Catchings, Rufus D.
Goldman, Mark R.
Ericksen, Todd L.
Glennie, Craig L.
Mechanics of near-field deformation during co- and post-seismic shallow fault slip
title Mechanics of near-field deformation during co- and post-seismic shallow fault slip
title_full Mechanics of near-field deformation during co- and post-seismic shallow fault slip
title_fullStr Mechanics of near-field deformation during co- and post-seismic shallow fault slip
title_full_unstemmed Mechanics of near-field deformation during co- and post-seismic shallow fault slip
title_short Mechanics of near-field deformation during co- and post-seismic shallow fault slip
title_sort mechanics of near-field deformation during co- and post-seismic shallow fault slip
topic Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7081326/
https://www.ncbi.nlm.nih.gov/pubmed/32193474
http://dx.doi.org/10.1038/s41598-020-61400-9
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