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What’s down there? The structures, materials and environment of deep-seated slow slip and tremor

Deep-seated slow slip and tremor (SST), including slow slip events, episodic tremor and slip, and low-frequency earthquakes, occur downdip of the seismogenic zone of numerous subduction megathrusts and plate boundary strike-slip faults. These events represent a fascinating and perplexing mode of fau...

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Autores principales: Behr, Whitney M., Bürgmann, Roland
Formato: Online Artículo Texto
Lenguaje:English
Publicado: The Royal Society Publishing 2021
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7898123/
https://www.ncbi.nlm.nih.gov/pubmed/33517877
http://dx.doi.org/10.1098/rsta.2020.0218
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author Behr, Whitney M.
Bürgmann, Roland
author_facet Behr, Whitney M.
Bürgmann, Roland
author_sort Behr, Whitney M.
collection PubMed
description Deep-seated slow slip and tremor (SST), including slow slip events, episodic tremor and slip, and low-frequency earthquakes, occur downdip of the seismogenic zone of numerous subduction megathrusts and plate boundary strike-slip faults. These events represent a fascinating and perplexing mode of fault failure that has greatly broadened our view of earthquake dynamics. In this contribution, we review constraints on SST deformation processes from both geophysical observations of active subduction zones and geological observations of exhumed field analogues. We first provide an overview of what has been learned about the environment, kinematics and dynamics of SST from geodetic and seismologic data. We then describe the materials, deformation mechanisms, and metamorphic and fluid pressure conditions that characterize exhumed rocks from SST source depths. Both the geophysical and geological records strongly suggest the importance of a fluid-rich and high fluid pressure habitat for the SST source region. Additionally, transient deformation features preserved in the rock record, involving combined frictional-viscous shear in regions of mixed lithology and near-lithostatic fluid pressures, may scale with the tremor component of SST. While several open questions remain, it is clear that improved constraints on the materials, environment, structure, and conditions of the plate interface from geophysical imaging and geologic observations will enhance model representations of the boundary conditions and geometry of the SST deformation process. This article is part of a discussion meeting issue ‘Understanding earthquakes using the geological record’.
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spelling pubmed-78981232021-02-23 What’s down there? The structures, materials and environment of deep-seated slow slip and tremor Behr, Whitney M. Bürgmann, Roland Philos Trans A Math Phys Eng Sci Articles Deep-seated slow slip and tremor (SST), including slow slip events, episodic tremor and slip, and low-frequency earthquakes, occur downdip of the seismogenic zone of numerous subduction megathrusts and plate boundary strike-slip faults. These events represent a fascinating and perplexing mode of fault failure that has greatly broadened our view of earthquake dynamics. In this contribution, we review constraints on SST deformation processes from both geophysical observations of active subduction zones and geological observations of exhumed field analogues. We first provide an overview of what has been learned about the environment, kinematics and dynamics of SST from geodetic and seismologic data. We then describe the materials, deformation mechanisms, and metamorphic and fluid pressure conditions that characterize exhumed rocks from SST source depths. Both the geophysical and geological records strongly suggest the importance of a fluid-rich and high fluid pressure habitat for the SST source region. Additionally, transient deformation features preserved in the rock record, involving combined frictional-viscous shear in regions of mixed lithology and near-lithostatic fluid pressures, may scale with the tremor component of SST. While several open questions remain, it is clear that improved constraints on the materials, environment, structure, and conditions of the plate interface from geophysical imaging and geologic observations will enhance model representations of the boundary conditions and geometry of the SST deformation process. This article is part of a discussion meeting issue ‘Understanding earthquakes using the geological record’. The Royal Society Publishing 2021-03-22 2021-02-01 /pmc/articles/PMC7898123/ /pubmed/33517877 http://dx.doi.org/10.1098/rsta.2020.0218 Text en © 2021 The Authors. http://creativecommons.org/licenses/by/4.0/ http://creativecommons.org/licenses/by/4.0/http://creativecommons.org/licenses/by/4.0/Published by the Royal Society under the terms of the Creative Commons Attribution License http://creativecommons.org/licenses/by/4.0/, which permits unrestricted use, provided the original author and source are credited.
spellingShingle Articles
Behr, Whitney M.
Bürgmann, Roland
What’s down there? The structures, materials and environment of deep-seated slow slip and tremor
title What’s down there? The structures, materials and environment of deep-seated slow slip and tremor
title_full What’s down there? The structures, materials and environment of deep-seated slow slip and tremor
title_fullStr What’s down there? The structures, materials and environment of deep-seated slow slip and tremor
title_full_unstemmed What’s down there? The structures, materials and environment of deep-seated slow slip and tremor
title_short What’s down there? The structures, materials and environment of deep-seated slow slip and tremor
title_sort what’s down there? the structures, materials and environment of deep-seated slow slip and tremor
topic Articles
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7898123/
https://www.ncbi.nlm.nih.gov/pubmed/33517877
http://dx.doi.org/10.1098/rsta.2020.0218
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