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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...
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Formato: | Online Artículo Texto |
Lenguaje: | English |
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American Association for the Advancement of Science
2020
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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 |
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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 |
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