Teleseismic earthquake swarms at ultraslow spreading ridges: indicator for dyke intrusions?
Earthquakes at mid-ocean ridges reflect the active magmatic and tectonic processes that form new oceanic crust. Studies of large earthquakes observed on land and smaller earthquakes observed locally or regionally by ocean bottom seismometers or autonomous underwater hydrophones have greatly contribu...
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Online Access: | https://epic.awi.de/id/eprint/30526/ http://onlinelibrary.wiley.com/doi/10.1111/j.1365-246X.2012.05502.x/abstract https://hdl.handle.net/10013/epic.39566 |
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ftawi:oai:epic.awi.de:30526 2023-05-15T15:02:01+02:00 Teleseismic earthquake swarms at ultraslow spreading ridges: indicator for dyke intrusions? Schlindwein, Vera 2012-05-21 https://epic.awi.de/id/eprint/30526/ http://onlinelibrary.wiley.com/doi/10.1111/j.1365-246X.2012.05502.x/abstract https://hdl.handle.net/10013/epic.39566 unknown WILEY-BLACKWELL PUBLISHING Schlindwein, V. orcid:0000-0001-5570-2753 (2012) Teleseismic earthquake swarms at ultraslow spreading ridges: indicator for dyke intrusions? , Geophysical Journal International, 190 (1), pp. 442-456 . doi:10.1111/j.1365-246X.2012.05502.x <https://doi.org/10.1111/j.1365-246X.2012.05502.x> , hdl:10013/epic.39566 EPIC3Geophysical Journal International, WILEY-BLACKWELL PUBLISHING, 190(1), pp. 442-456, ISSN: 0956-540X Article isiRev 2012 ftawi 2021-12-24T15:37:44Z Earthquakes at mid-ocean ridges reflect the active magmatic and tectonic processes that form new oceanic crust. Studies of large earthquakes observed on land and smaller earthquakes observed locally or regionally by ocean bottom seismometers or autonomous underwater hydrophones have greatly contributed to our understanding of the structure and active spreading processes at the mid-ocean ridges of the Atlantic and Pacific Ocean opening with velocities in excess of 25 mm yr–1. At spreading rates below 20 mm yr–1 full rate, the appearance and the accretion processes of mid-ocean ridges undergo fundamental changes as the melt supply is drastically reduced. The active spreading processes at these so-called ultraslow spreading ridges are still poorly known, as the main representatives, the Arctic Ridge System and the Southwest Indian Ridge, are poorly accessible and neither autonomous underwater hydrophone nor ocean bottom seismometer records of local seismicity are available. In an attempt to compare on a large scale the accretion style of ultraslow spreading ridge sections, I analyse the teleseismically recorded seismicity in 11 sections of the Arctic Ridge System and the Southwest Indian Ridge spanning altogether 7200 km. Epicentres located within 30–35 km of the rift axis were extracted from the catalogue of the International Seismological Centre for a time period of 35 yr. On the basis of a single-link cluster analysis, I identified 27 swarms with eight or more events. These swarms occur almost exclusively at centres of focussed magmatism suggesting that the swarms are probably initiated by magmatism. Normal faults along several tens of kilometres surrounding the volcanic centres react in large earthquakes (M > 5) to dyke emplacement. The routine generation of large earthquakes in the cold, brittle lithosphere of ultraslow spreading ridges makes the teleseismic record a valuable means to study ultraslow accretion processes and to provide a global framework for the interpretation of the limited local and regional seismicity studies. Article in Journal/Newspaper Arctic Alfred Wegener Institute for Polar- and Marine Research (AWI): ePIC (electronic Publication Information Center) Arctic Pacific Indian Geophysical Journal International 190 1 442 456 |
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Alfred Wegener Institute for Polar- and Marine Research (AWI): ePIC (electronic Publication Information Center) |
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ftawi |
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unknown |
description |
Earthquakes at mid-ocean ridges reflect the active magmatic and tectonic processes that form new oceanic crust. Studies of large earthquakes observed on land and smaller earthquakes observed locally or regionally by ocean bottom seismometers or autonomous underwater hydrophones have greatly contributed to our understanding of the structure and active spreading processes at the mid-ocean ridges of the Atlantic and Pacific Ocean opening with velocities in excess of 25 mm yr–1. At spreading rates below 20 mm yr–1 full rate, the appearance and the accretion processes of mid-ocean ridges undergo fundamental changes as the melt supply is drastically reduced. The active spreading processes at these so-called ultraslow spreading ridges are still poorly known, as the main representatives, the Arctic Ridge System and the Southwest Indian Ridge, are poorly accessible and neither autonomous underwater hydrophone nor ocean bottom seismometer records of local seismicity are available. In an attempt to compare on a large scale the accretion style of ultraslow spreading ridge sections, I analyse the teleseismically recorded seismicity in 11 sections of the Arctic Ridge System and the Southwest Indian Ridge spanning altogether 7200 km. Epicentres located within 30–35 km of the rift axis were extracted from the catalogue of the International Seismological Centre for a time period of 35 yr. On the basis of a single-link cluster analysis, I identified 27 swarms with eight or more events. These swarms occur almost exclusively at centres of focussed magmatism suggesting that the swarms are probably initiated by magmatism. Normal faults along several tens of kilometres surrounding the volcanic centres react in large earthquakes (M > 5) to dyke emplacement. The routine generation of large earthquakes in the cold, brittle lithosphere of ultraslow spreading ridges makes the teleseismic record a valuable means to study ultraslow accretion processes and to provide a global framework for the interpretation of the limited local and regional seismicity studies. |
format |
Article in Journal/Newspaper |
author |
Schlindwein, Vera |
spellingShingle |
Schlindwein, Vera Teleseismic earthquake swarms at ultraslow spreading ridges: indicator for dyke intrusions? |
author_facet |
Schlindwein, Vera |
author_sort |
Schlindwein, Vera |
title |
Teleseismic earthquake swarms at ultraslow spreading ridges: indicator for dyke intrusions? |
title_short |
Teleseismic earthquake swarms at ultraslow spreading ridges: indicator for dyke intrusions? |
title_full |
Teleseismic earthquake swarms at ultraslow spreading ridges: indicator for dyke intrusions? |
title_fullStr |
Teleseismic earthquake swarms at ultraslow spreading ridges: indicator for dyke intrusions? |
title_full_unstemmed |
Teleseismic earthquake swarms at ultraslow spreading ridges: indicator for dyke intrusions? |
title_sort |
teleseismic earthquake swarms at ultraslow spreading ridges: indicator for dyke intrusions? |
publisher |
WILEY-BLACKWELL PUBLISHING |
publishDate |
2012 |
url |
https://epic.awi.de/id/eprint/30526/ http://onlinelibrary.wiley.com/doi/10.1111/j.1365-246X.2012.05502.x/abstract https://hdl.handle.net/10013/epic.39566 |
geographic |
Arctic Pacific Indian |
geographic_facet |
Arctic Pacific Indian |
genre |
Arctic |
genre_facet |
Arctic |
op_source |
EPIC3Geophysical Journal International, WILEY-BLACKWELL PUBLISHING, 190(1), pp. 442-456, ISSN: 0956-540X |
op_relation |
Schlindwein, V. orcid:0000-0001-5570-2753 (2012) Teleseismic earthquake swarms at ultraslow spreading ridges: indicator for dyke intrusions? , Geophysical Journal International, 190 (1), pp. 442-456 . doi:10.1111/j.1365-246X.2012.05502.x <https://doi.org/10.1111/j.1365-246X.2012.05502.x> , hdl:10013/epic.39566 |
container_title |
Geophysical Journal International |
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190 |
container_issue |
1 |
container_start_page |
442 |
op_container_end_page |
456 |
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1766334011914846208 |