Earthquake rupture below the brittle-ductile transition in continental lithospheric mantle
Earthquakes deep in the continental lithosphere are rare and hard to interpret in our current understanding of temperature control on brittle failure. The recent lithospheric mantle earthquake with a moment magnitude of 4.8 at a depth of ~75 km in the Wyoming Craton was exceptionally well recorded a...
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American Association for the Advancement of Science (AAAS)
2017
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Online Access: | http://hdl.handle.net/1721.1/110061 https://orcid.org/0000-0001-8681-8572 https://orcid.org/0000-0002-6493-5142 |
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author | Prieto, German A. Froment, Berenice Abercrombie, Rachel Yu, Chunquan Poli, Piero |
author2 | Massachusetts Institute of Technology. Department of Earth, Atmospheric, and Planetary Sciences |
author_facet | Massachusetts Institute of Technology. Department of Earth, Atmospheric, and Planetary Sciences Prieto, German A. Froment, Berenice Abercrombie, Rachel Yu, Chunquan Poli, Piero |
author_sort | Prieto, German A. |
collection | MIT |
description | Earthquakes deep in the continental lithosphere are rare and hard to interpret in our current understanding of temperature control on brittle failure. The recent lithospheric mantle earthquake with a moment magnitude of 4.8 at a depth of ~75 km in the Wyoming Craton was exceptionally well recorded and thus enabled us to probe the cause of these unusual earthquakes. On the basis of complete earthquake energy balance estimates using broadband waveforms and temperature estimates using surface heat flow and shear wave velocities, we argue that this earthquake occurred in response to ductile deformation at temperatures above 750°C. The high stress drop, low rupture velocity, and low radiation efficiency are all consistent with a dissipative mechanism. Our results imply that earthquake nucleation in the lithospheric mantle is not exclusively limited to the brittle regime; weakening mechanisms in the ductile regime can allow earthquakes to initiate and propagate. This finding has significant implications for understanding deep earthquake rupture mechanics and rheology of the continental lithosphere. |
first_indexed | 2024-09-23T14:57:09Z |
format | Article |
id | mit-1721.1/110061 |
institution | Massachusetts Institute of Technology |
language | en_US |
last_indexed | 2024-09-23T14:57:09Z |
publishDate | 2017 |
publisher | American Association for the Advancement of Science (AAAS) |
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spelling | mit-1721.1/1100612022-09-29T11:40:14Z Earthquake rupture below the brittle-ductile transition in continental lithospheric mantle Prieto, German A. Froment, Berenice Abercrombie, Rachel Yu, Chunquan Poli, Piero Massachusetts Institute of Technology. Department of Earth, Atmospheric, and Planetary Sciences Yu, Chunquan Poli, Piero Earthquakes deep in the continental lithosphere are rare and hard to interpret in our current understanding of temperature control on brittle failure. The recent lithospheric mantle earthquake with a moment magnitude of 4.8 at a depth of ~75 km in the Wyoming Craton was exceptionally well recorded and thus enabled us to probe the cause of these unusual earthquakes. On the basis of complete earthquake energy balance estimates using broadband waveforms and temperature estimates using surface heat flow and shear wave velocities, we argue that this earthquake occurred in response to ductile deformation at temperatures above 750°C. The high stress drop, low rupture velocity, and low radiation efficiency are all consistent with a dissipative mechanism. Our results imply that earthquake nucleation in the lithospheric mantle is not exclusively limited to the brittle regime; weakening mechanisms in the ductile regime can allow earthquakes to initiate and propagate. This finding has significant implications for understanding deep earthquake rupture mechanics and rheology of the continental lithosphere. National Science Foundation (U.S.) (EAR-1521534) National Science Foundation (U.S.) (EAR-1261681) 2017-06-20T15:49:09Z 2017-06-20T15:49:09Z 2017-02 2016-10 Article http://purl.org/eprint/type/JournalArticle 2375-2548 http://hdl.handle.net/1721.1/110061 Prieto, Germán A.; Froment, Bérénice; Yu, Chunquan; Poli, Piero and Abercrombie, Rachel. “Earthquake Rupture Below the Brittle-Ductile Transition in Continental Lithospheric Mantle.” Science Advances 3, no. 3 (March 2017): e1602642. © 2017 The Authors https://orcid.org/0000-0001-8681-8572 https://orcid.org/0000-0002-6493-5142 en_US http://dx.doi.org/10.1126/sciadv.1602642 Science Advances Creative Commons Attribution-NonCommercial 4.0 International http://creativecommons.org/licenses/by-nc/4.0/ application/pdf American Association for the Advancement of Science (AAAS) AAAS |
spellingShingle | Prieto, German A. Froment, Berenice Abercrombie, Rachel Yu, Chunquan Poli, Piero Earthquake rupture below the brittle-ductile transition in continental lithospheric mantle |
title | Earthquake rupture below the brittle-ductile transition in continental lithospheric mantle |
title_full | Earthquake rupture below the brittle-ductile transition in continental lithospheric mantle |
title_fullStr | Earthquake rupture below the brittle-ductile transition in continental lithospheric mantle |
title_full_unstemmed | Earthquake rupture below the brittle-ductile transition in continental lithospheric mantle |
title_short | Earthquake rupture below the brittle-ductile transition in continental lithospheric mantle |
title_sort | earthquake rupture below the brittle ductile transition in continental lithospheric mantle |
url | http://hdl.handle.net/1721.1/110061 https://orcid.org/0000-0001-8681-8572 https://orcid.org/0000-0002-6493-5142 |
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