The 1999 earthquake swarm at Gakkel Ridge, Arctic Ocean Relocalization and Analysis
In 1999 lasting over 7 months, the largest ever earthquake swarm at a mid-ocean ridge was teleseismically registered worldwide. It featured 252 recorded events, including 11 events with a magnitude mb>5.0 and originated from around 85°E at the eastern Gakkel Ridge (full spreading rate 6-14 mm/yr)...
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ftawi:oai:epic.awi.de:21962 2023-05-15T14:24:37+02:00 The 1999 earthquake swarm at Gakkel Ridge, Arctic Ocean Relocalization and Analysis Korger, Edith Schlindwein, Vera Riedel, Carsten 2010 https://epic.awi.de/id/eprint/21962/ https://hdl.handle.net/10013/epic.34194 unknown Korger, E. , Schlindwein, V. orcid:0000-0001-5570-2753 and Riedel, C. (2010) The 1999 earthquake swarm at Gakkel Ridge, Arctic Ocean Relocalization and Analysis , 70. Jahrestagung der Deutschen Geophysikalischen Gesellschaft. . hdl:10013/epic.34194 EPIC370. Jahrestagung der Deutschen Geophysikalischen Gesellschaft. Conference notRev 2010 ftawi 2021-12-24T15:34:02Z In 1999 lasting over 7 months, the largest ever earthquake swarm at a mid-ocean ridge was teleseismically registered worldwide. It featured 252 recorded events, including 11 events with a magnitude mb>5.0 and originated from around 85°E at the eastern Gakkel Ridge (full spreading rate 6-14 mm/yr). This makes it indicative for active spreading processes at ultraslow spreading ridges where heat loss by conductive cooling is thought to decrease magma supply and focus magmatism in widely spaced discrete volcanic centres. The relocalization was done with the routine NonLinLoc using a probabilistic approach. The new locations of the epicentres show a clustering of events within the central rift valley and the southern rift flank, the 68% error in ellipse semi-major axes of the new localization is in the order of 15 km for the best events. An analysis of the respective epicentral distance to the volcanic complex with advancing time showed high seismicity and diffuse activation around the volcanic complex within the rift valley before the 15th of April, to the NW migrating epicentres with additional activation of the valley walls and a marked drop in seismicity after April 15th. We postulate that the change in seismicity rate and the following change in source mechanism might mark the onset of volcanic activity and may be reflected by three events with highly correlating waveforms at the beginning of April. Conference Object Arctic Arctic Arctic Ocean Alfred Wegener Institute for Polar- and Marine Research (AWI): ePIC (electronic Publication Information Center) Arctic Arctic Ocean Gakkel Ridge ENVELOPE(90.000,90.000,87.000,87.000) |
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Alfred Wegener Institute for Polar- and Marine Research (AWI): ePIC (electronic Publication Information Center) |
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description |
In 1999 lasting over 7 months, the largest ever earthquake swarm at a mid-ocean ridge was teleseismically registered worldwide. It featured 252 recorded events, including 11 events with a magnitude mb>5.0 and originated from around 85°E at the eastern Gakkel Ridge (full spreading rate 6-14 mm/yr). This makes it indicative for active spreading processes at ultraslow spreading ridges where heat loss by conductive cooling is thought to decrease magma supply and focus magmatism in widely spaced discrete volcanic centres. The relocalization was done with the routine NonLinLoc using a probabilistic approach. The new locations of the epicentres show a clustering of events within the central rift valley and the southern rift flank, the 68% error in ellipse semi-major axes of the new localization is in the order of 15 km for the best events. An analysis of the respective epicentral distance to the volcanic complex with advancing time showed high seismicity and diffuse activation around the volcanic complex within the rift valley before the 15th of April, to the NW migrating epicentres with additional activation of the valley walls and a marked drop in seismicity after April 15th. We postulate that the change in seismicity rate and the following change in source mechanism might mark the onset of volcanic activity and may be reflected by three events with highly correlating waveforms at the beginning of April. |
format |
Conference Object |
author |
Korger, Edith Schlindwein, Vera Riedel, Carsten |
spellingShingle |
Korger, Edith Schlindwein, Vera Riedel, Carsten The 1999 earthquake swarm at Gakkel Ridge, Arctic Ocean Relocalization and Analysis |
author_facet |
Korger, Edith Schlindwein, Vera Riedel, Carsten |
author_sort |
Korger, Edith |
title |
The 1999 earthquake swarm at Gakkel Ridge, Arctic Ocean Relocalization and Analysis |
title_short |
The 1999 earthquake swarm at Gakkel Ridge, Arctic Ocean Relocalization and Analysis |
title_full |
The 1999 earthquake swarm at Gakkel Ridge, Arctic Ocean Relocalization and Analysis |
title_fullStr |
The 1999 earthquake swarm at Gakkel Ridge, Arctic Ocean Relocalization and Analysis |
title_full_unstemmed |
The 1999 earthquake swarm at Gakkel Ridge, Arctic Ocean Relocalization and Analysis |
title_sort |
1999 earthquake swarm at gakkel ridge, arctic ocean relocalization and analysis |
publishDate |
2010 |
url |
https://epic.awi.de/id/eprint/21962/ https://hdl.handle.net/10013/epic.34194 |
long_lat |
ENVELOPE(90.000,90.000,87.000,87.000) |
geographic |
Arctic Arctic Ocean Gakkel Ridge |
geographic_facet |
Arctic Arctic Ocean Gakkel Ridge |
genre |
Arctic Arctic Arctic Ocean |
genre_facet |
Arctic Arctic Arctic Ocean |
op_source |
EPIC370. Jahrestagung der Deutschen Geophysikalischen Gesellschaft. |
op_relation |
Korger, E. , Schlindwein, V. orcid:0000-0001-5570-2753 and Riedel, C. (2010) The 1999 earthquake swarm at Gakkel Ridge, Arctic Ocean Relocalization and Analysis , 70. Jahrestagung der Deutschen Geophysikalischen Gesellschaft. . hdl:10013/epic.34194 |
_version_ |
1766297053446537216 |