Cargando…

Deep slab seismicity limited by rate of deformation in the transition zone

Deep earthquakes within subducting tectonic plates (slabs) are enigmatic because they appear similar to shallow earthquakes but must occur by a different mechanism. Previous attempts to explain the depth distribution of deep earthquakes in terms of the temperature at which possible triggering mechan...

Descripción completa

Detalles Bibliográficos
Autor principal: Billen, Magali I.
Formato: Online Artículo Texto
Lenguaje:English
Publicado: American Association for the Advancement of Science 2020
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7385466/
https://www.ncbi.nlm.nih.gov/pubmed/32766442
http://dx.doi.org/10.1126/sciadv.aaz7692
_version_ 1783563791076687872
author Billen, Magali I.
author_facet Billen, Magali I.
author_sort Billen, Magali I.
collection PubMed
description Deep earthquakes within subducting tectonic plates (slabs) are enigmatic because they appear similar to shallow earthquakes but must occur by a different mechanism. Previous attempts to explain the depth distribution of deep earthquakes in terms of the temperature at which possible triggering mechanisms are viable, fail to explain the spatial variability in seismicity. In addition to thermal constraints, proposed failure mechanisms for deep earthquakes all require that sufficient strain accumulates in the slab at a relatively high stress. Here, I show that simulations of subduction with nonlinear rheology and compositionally dependent phase transitions exhibit strongly variable strain rates in space and time, which is similar to observed seismicity. Therefore, in addition to temperature, variations in strain rate may explain why there are large gaps in deep seismicity (low strain rate), and variable peaks in seismicity (bending regions), and, possibly, why there is an abrupt cessation of seismicity below 660 km.
format Online
Article
Text
id pubmed-7385466
institution National Center for Biotechnology Information
language English
publishDate 2020
publisher American Association for the Advancement of Science
record_format MEDLINE/PubMed
spelling pubmed-73854662020-08-05 Deep slab seismicity limited by rate of deformation in the transition zone Billen, Magali I. Sci Adv Research Articles Deep earthquakes within subducting tectonic plates (slabs) are enigmatic because they appear similar to shallow earthquakes but must occur by a different mechanism. Previous attempts to explain the depth distribution of deep earthquakes in terms of the temperature at which possible triggering mechanisms are viable, fail to explain the spatial variability in seismicity. In addition to thermal constraints, proposed failure mechanisms for deep earthquakes all require that sufficient strain accumulates in the slab at a relatively high stress. Here, I show that simulations of subduction with nonlinear rheology and compositionally dependent phase transitions exhibit strongly variable strain rates in space and time, which is similar to observed seismicity. Therefore, in addition to temperature, variations in strain rate may explain why there are large gaps in deep seismicity (low strain rate), and variable peaks in seismicity (bending regions), and, possibly, why there is an abrupt cessation of seismicity below 660 km. American Association for the Advancement of Science 2020-05-27 /pmc/articles/PMC7385466/ /pubmed/32766442 http://dx.doi.org/10.1126/sciadv.aaz7692 Text en Copyright © 2020 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). http://creativecommons.org/licenses/by-nc/4.0/ This is an open-access article distributed under the terms of the Creative Commons Attribution-NonCommercial license (http://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
Billen, Magali I.
Deep slab seismicity limited by rate of deformation in the transition zone
title Deep slab seismicity limited by rate of deformation in the transition zone
title_full Deep slab seismicity limited by rate of deformation in the transition zone
title_fullStr Deep slab seismicity limited by rate of deformation in the transition zone
title_full_unstemmed Deep slab seismicity limited by rate of deformation in the transition zone
title_short Deep slab seismicity limited by rate of deformation in the transition zone
title_sort deep slab seismicity limited by rate of deformation in the transition zone
topic Research Articles
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7385466/
https://www.ncbi.nlm.nih.gov/pubmed/32766442
http://dx.doi.org/10.1126/sciadv.aaz7692
work_keys_str_mv AT billenmagalii deepslabseismicitylimitedbyrateofdeformationinthetransitionzone