Magma-maintained rift segmentation at continental rupture in the 2005 Afar dyking episode
Seafloor spreading centres show a regular along-axis segmentation thought to be produced by a segmented magma supply in the passively upwelling mantle. On the other hand, continental rifts are segmented by large offset normal faults, and many lack magmatism. It is unclear how, when and where the ubi...
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Online Access: | https://hdl.handle.net/1983/86f5cd54-48a1-495b-9798-3ca1163269fb https://research-information.bris.ac.uk/en/publications/86f5cd54-48a1-495b-9798-3ca1163269fb https://doi.org/10.1038/nature04978 http://www.scopus.com/inward/record.url?scp=33746338621&partnerID=8YFLogxK |
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ftubristolcris:oai:research-information.bris.ac.uk:publications/86f5cd54-48a1-495b-9798-3ca1163269fb 2024-05-19T07:42:44+00:00 Magma-maintained rift segmentation at continental rupture in the 2005 Afar dyking episode Wright, Tim J. Ebinger, Cindy Biggs, Juliet Ayele, Atalay Yirgu, Gezahegn Keir, Derek Stork, Anna 2006-07-20 https://hdl.handle.net/1983/86f5cd54-48a1-495b-9798-3ca1163269fb https://research-information.bris.ac.uk/en/publications/86f5cd54-48a1-495b-9798-3ca1163269fb https://doi.org/10.1038/nature04978 http://www.scopus.com/inward/record.url?scp=33746338621&partnerID=8YFLogxK eng eng https://research-information.bris.ac.uk/en/publications/86f5cd54-48a1-495b-9798-3ca1163269fb info:eu-repo/semantics/restrictedAccess Wright , T J , Ebinger , C , Biggs , J , Ayele , A , Yirgu , G , Keir , D & Stork , A 2006 , ' Magma-maintained rift segmentation at continental rupture in the 2005 Afar dyking episode ' , Nature , vol. 442 , no. 7100 , pp. 291-294 . https://doi.org/10.1038/nature04978 EARTHQUAKES ACCUMULATION 1960 COLLAPSE KILAUEA VOLCANO DEFORMATION PLATE BOUNDARY ACCRETION SURFACE UPLIFT NORTHEAST ICELAND SUBSIDENCE article 2006 ftubristolcris https://doi.org/10.1038/nature04978 2024-04-23T23:44:10Z Seafloor spreading centres show a regular along-axis segmentation thought to be produced by a segmented magma supply in the passively upwelling mantle. On the other hand, continental rifts are segmented by large offset normal faults, and many lack magmatism. It is unclear how, when and where the ubiquitous segmented melt zones are emplaced during the continental rupture process. Between 14 September and 4 October 2005, 163 earthquakes (magnitudes greater than 3.9) and a volcanic eruption occurred within the ∼60-km-long Dabbahu magmatic segment of the Afar rift, a nascent seafloor spreading centre in stretched continental lithosphere. Here we present a three-dimensional deformation field for the Dabbahu rifting episode derived from satellite radar data, which shows that the entire segment ruptured, making it the largest to have occurred on land in the era of satellite geodesy. Simple elastic modelling shows that the magmatic segment opened by up to 8 m, yet seismic rupture can account for only 8 per cent of the observed deformation. Magma was injected along a dyke between depths of 2 and 9 km, corresponding to a total intrusion volume of ∼2.5 km 3 . Much of the magma appears to have originated from shallow chambers beneath Dabbahu and Gabho volcanoes at the northern end of the segment, where an explosive fissural eruption occurred on 26 September 2005. Although comparable in magnitude to the ten year (1975-84) Krafla events in Iceland, seismic data suggest that most of the Dabbahu dyke intrusion occurred in less than a week. Thus, magma intrusion via dyking, rather than segmented normal faulting, maintains and probably initiated the along-axis segmentation along this sector of the Nubia-Arabia plate boundary. © 2006 Nature Publishing Group. Article in Journal/Newspaper Iceland University of Bristol: Bristol Research Nature 442 7100 291 294 |
institution |
Open Polar |
collection |
University of Bristol: Bristol Research |
op_collection_id |
ftubristolcris |
language |
English |
topic |
EARTHQUAKES ACCUMULATION 1960 COLLAPSE KILAUEA VOLCANO DEFORMATION PLATE BOUNDARY ACCRETION SURFACE UPLIFT NORTHEAST ICELAND SUBSIDENCE |
spellingShingle |
EARTHQUAKES ACCUMULATION 1960 COLLAPSE KILAUEA VOLCANO DEFORMATION PLATE BOUNDARY ACCRETION SURFACE UPLIFT NORTHEAST ICELAND SUBSIDENCE Wright, Tim J. Ebinger, Cindy Biggs, Juliet Ayele, Atalay Yirgu, Gezahegn Keir, Derek Stork, Anna Magma-maintained rift segmentation at continental rupture in the 2005 Afar dyking episode |
topic_facet |
EARTHQUAKES ACCUMULATION 1960 COLLAPSE KILAUEA VOLCANO DEFORMATION PLATE BOUNDARY ACCRETION SURFACE UPLIFT NORTHEAST ICELAND SUBSIDENCE |
description |
Seafloor spreading centres show a regular along-axis segmentation thought to be produced by a segmented magma supply in the passively upwelling mantle. On the other hand, continental rifts are segmented by large offset normal faults, and many lack magmatism. It is unclear how, when and where the ubiquitous segmented melt zones are emplaced during the continental rupture process. Between 14 September and 4 October 2005, 163 earthquakes (magnitudes greater than 3.9) and a volcanic eruption occurred within the ∼60-km-long Dabbahu magmatic segment of the Afar rift, a nascent seafloor spreading centre in stretched continental lithosphere. Here we present a three-dimensional deformation field for the Dabbahu rifting episode derived from satellite radar data, which shows that the entire segment ruptured, making it the largest to have occurred on land in the era of satellite geodesy. Simple elastic modelling shows that the magmatic segment opened by up to 8 m, yet seismic rupture can account for only 8 per cent of the observed deformation. Magma was injected along a dyke between depths of 2 and 9 km, corresponding to a total intrusion volume of ∼2.5 km 3 . Much of the magma appears to have originated from shallow chambers beneath Dabbahu and Gabho volcanoes at the northern end of the segment, where an explosive fissural eruption occurred on 26 September 2005. Although comparable in magnitude to the ten year (1975-84) Krafla events in Iceland, seismic data suggest that most of the Dabbahu dyke intrusion occurred in less than a week. Thus, magma intrusion via dyking, rather than segmented normal faulting, maintains and probably initiated the along-axis segmentation along this sector of the Nubia-Arabia plate boundary. © 2006 Nature Publishing Group. |
format |
Article in Journal/Newspaper |
author |
Wright, Tim J. Ebinger, Cindy Biggs, Juliet Ayele, Atalay Yirgu, Gezahegn Keir, Derek Stork, Anna |
author_facet |
Wright, Tim J. Ebinger, Cindy Biggs, Juliet Ayele, Atalay Yirgu, Gezahegn Keir, Derek Stork, Anna |
author_sort |
Wright, Tim J. |
title |
Magma-maintained rift segmentation at continental rupture in the 2005 Afar dyking episode |
title_short |
Magma-maintained rift segmentation at continental rupture in the 2005 Afar dyking episode |
title_full |
Magma-maintained rift segmentation at continental rupture in the 2005 Afar dyking episode |
title_fullStr |
Magma-maintained rift segmentation at continental rupture in the 2005 Afar dyking episode |
title_full_unstemmed |
Magma-maintained rift segmentation at continental rupture in the 2005 Afar dyking episode |
title_sort |
magma-maintained rift segmentation at continental rupture in the 2005 afar dyking episode |
publishDate |
2006 |
url |
https://hdl.handle.net/1983/86f5cd54-48a1-495b-9798-3ca1163269fb https://research-information.bris.ac.uk/en/publications/86f5cd54-48a1-495b-9798-3ca1163269fb https://doi.org/10.1038/nature04978 http://www.scopus.com/inward/record.url?scp=33746338621&partnerID=8YFLogxK |
genre |
Iceland |
genre_facet |
Iceland |
op_source |
Wright , T J , Ebinger , C , Biggs , J , Ayele , A , Yirgu , G , Keir , D & Stork , A 2006 , ' Magma-maintained rift segmentation at continental rupture in the 2005 Afar dyking episode ' , Nature , vol. 442 , no. 7100 , pp. 291-294 . https://doi.org/10.1038/nature04978 |
op_relation |
https://research-information.bris.ac.uk/en/publications/86f5cd54-48a1-495b-9798-3ca1163269fb |
op_rights |
info:eu-repo/semantics/restrictedAccess |
op_doi |
https://doi.org/10.1038/nature04978 |
container_title |
Nature |
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442 |
container_issue |
7100 |
container_start_page |
291 |
op_container_end_page |
294 |
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1799482423338074112 |