Interseismic deformation at subduction zones investigated by 2D numerical modeling: case study before the 2010 Maule earthquake

We study interseismic deformation preceding the Mw8.8 2010 Maule earthquake by means of two-dimensional finite-element modeling. Our goal is to gain insight into the fundamental factors controlling elastic strain build-up and release in subduction zones, and to evaluate different modeling approaches...

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Autores principales:	Contreras,Marcelo, Tassara,Andrés, Gerbault,Muriel, Araya,Rodolfo, Bataille,Klaus
Lenguaje:	English
Publicado:	Servicio Nacional de Geología y Minería (SERNAGEOMIN) 2016
Materias:	Interseismic deformation GPS surface velocity Maule earthquake Stress Subduction FEM
Acceso en línea:	http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0718-71062016000300001
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spelling	oai:scielo:S0718-710620160003000012016-11-09Interseismic deformation at subduction zones investigated by 2D numerical modeling: case study before the 2010 Maule earthquakeContreras,MarceloTassara,AndrésGerbault,MurielAraya,RodolfoBataille,Klaus Interseismic deformation GPS surface velocity Maule earthquake Stress Subduction FEM We study interseismic deformation preceding the Mw8.8 2010 Maule earthquake by means of two-dimensional finite-element modeling. Our goal is to gain insight into the fundamental factors controlling elastic strain build-up and release in subduction zones, and to evaluate different modeling approaches of surface displacement as observed by GPS. We developed a linear elasticity solver that allows us to implement a realistic subducting plate geometry constrained by geophysical data. We test the influence of subducting plate thickness, variations in the updip and downdip limit of a 100% locked interplate zone, elastic parameters, and velocity reduction at the base of the subducted slab. We compared our modeled predictions with interseismic GPS observations along an EW profile crossing the Maule earthquake rupture area, in order to determine best fitting parameters. Our results indicate little influence of the subducting plate thickness at a given downdip limit, which itself has a strong influence on surface deformation. However, the fit to observations is achieved only after reducing the velocity at the base of the subducted slab below the trench region to 10% of the far-field convergence rate. We link this novel result to complementary numerical models that gradually evolve toward considering longer time-scales and complex rheology in order to evaluate the mechanical meaning of the above mentioned inferred kinematic conditions. This allowed us to link the velocity reduction at the base of subducting slabs with a long-term state of high flexural stress resulting from the mechanical interaction of the slab with the underlying mantle. Even a small amount of theses high deviatoric stresses may transfer towards the upper portion of the slab as strain energy that could participate into the mechanical loading of the megathrust and therefore in triggering large earthquakes there.info:eu-repo/semantics/openAccessServicio Nacional de Geología y Minería (SERNAGEOMIN)Andean geology v.43 n.3 20162016-09-01text/htmlhttp://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0718-71062016000300001en10.5027/andgeoV43n3-a01
institution	Scielo Chile
collection	Scielo Chile
language	English
topic	Interseismic deformation GPS surface velocity Maule earthquake Stress Subduction FEM
spellingShingle	Interseismic deformation GPS surface velocity Maule earthquake Stress Subduction FEM Contreras,Marcelo Tassara,Andrés Gerbault,Muriel Araya,Rodolfo Bataille,Klaus Interseismic deformation at subduction zones investigated by 2D numerical modeling: case study before the 2010 Maule earthquake
description	We study interseismic deformation preceding the Mw8.8 2010 Maule earthquake by means of two-dimensional finite-element modeling. Our goal is to gain insight into the fundamental factors controlling elastic strain build-up and release in subduction zones, and to evaluate different modeling approaches of surface displacement as observed by GPS. We developed a linear elasticity solver that allows us to implement a realistic subducting plate geometry constrained by geophysical data. We test the influence of subducting plate thickness, variations in the updip and downdip limit of a 100% locked interplate zone, elastic parameters, and velocity reduction at the base of the subducted slab. We compared our modeled predictions with interseismic GPS observations along an EW profile crossing the Maule earthquake rupture area, in order to determine best fitting parameters. Our results indicate little influence of the subducting plate thickness at a given downdip limit, which itself has a strong influence on surface deformation. However, the fit to observations is achieved only after reducing the velocity at the base of the subducted slab below the trench region to 10% of the far-field convergence rate. We link this novel result to complementary numerical models that gradually evolve toward considering longer time-scales and complex rheology in order to evaluate the mechanical meaning of the above mentioned inferred kinematic conditions. This allowed us to link the velocity reduction at the base of subducting slabs with a long-term state of high flexural stress resulting from the mechanical interaction of the slab with the underlying mantle. Even a small amount of theses high deviatoric stresses may transfer towards the upper portion of the slab as strain energy that could participate into the mechanical loading of the megathrust and therefore in triggering large earthquakes there.
author	Contreras,Marcelo Tassara,Andrés Gerbault,Muriel Araya,Rodolfo Bataille,Klaus
author_facet	Contreras,Marcelo Tassara,Andrés Gerbault,Muriel Araya,Rodolfo Bataille,Klaus
author_sort	Contreras,Marcelo
title	Interseismic deformation at subduction zones investigated by 2D numerical modeling: case study before the 2010 Maule earthquake
title_short	Interseismic deformation at subduction zones investigated by 2D numerical modeling: case study before the 2010 Maule earthquake
title_full	Interseismic deformation at subduction zones investigated by 2D numerical modeling: case study before the 2010 Maule earthquake
title_fullStr	Interseismic deformation at subduction zones investigated by 2D numerical modeling: case study before the 2010 Maule earthquake
title_full_unstemmed	Interseismic deformation at subduction zones investigated by 2D numerical modeling: case study before the 2010 Maule earthquake
title_sort	interseismic deformation at subduction zones investigated by 2d numerical modeling: case study before the 2010 maule earthquake
publisher	Servicio Nacional de Geología y Minería (SERNAGEOMIN)
publishDate	2016
url	http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0718-71062016000300001
work_keys_str_mv	AT contrerasmarcelo interseismicdeformationatsubductionzonesinvestigatedby2dnumericalmodelingcasestudybeforethe2010mauleearthquake AT tassaraandres interseismicdeformationatsubductionzonesinvestigatedby2dnumericalmodelingcasestudybeforethe2010mauleearthquake AT gerbaultmuriel interseismicdeformationatsubductionzonesinvestigatedby2dnumericalmodelingcasestudybeforethe2010mauleearthquake AT arayarodolfo interseismicdeformationatsubductionzonesinvestigatedby2dnumericalmodelingcasestudybeforethe2010mauleearthquake AT batailleklaus interseismicdeformationatsubductionzonesinvestigatedby2dnumericalmodelingcasestudybeforethe2010mauleearthquake
_version_	1714205853349838848

Interseismic deformation at subduction zones investigated by 2D numerical modeling: case study before the 2010 Maule earthquake

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