Initial results from the ICEMELT Experiment: Body-wave delay times and shear-wave splitting across Iceland
We present results from the first stage of the ICEMELT broadband seismometer experiment designed to determine upper mantle structure beneath Iceland, a hotspot located on the Mid-Atlantic Ridge. Relative delays of teleseismic body waves across Iceland are in excess of l s for P waves and as large as...
Published in: | Geophysical Research Letters |
---|---|
Main Authors: | , , , |
Other Authors: | , , , , , |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
Wiley-Blackwell
1996
|
Subjects: | |
Online Access: | https://hdl.handle.net/20.500.11815/496 https://doi.org/10.1029/96GL00420 |
id |
ftopinvisindi:oai:opinvisindi.is:20.500.11815/496 |
---|---|
record_format |
openpolar |
spelling |
ftopinvisindi:oai:opinvisindi.is:20.500.11815/496 2024-09-15T18:13:16+00:00 Initial results from the ICEMELT Experiment: Body-wave delay times and shear-wave splitting across Iceland Bjarnason, Ingi Þorleifur Wolfe, Cecily J. Solomon, Sean C. Guðmundsson, Gunnar Raunvísindastofnun (HÍ) Science Institute (UI) Verkfræði- og náttúruvísindasvið (HÍ) School of Engineering and Natural Sciences (UI) Háskóli Íslands University of Iceland 1996-03-01 459-462 https://hdl.handle.net/20.500.11815/496 https://doi.org/10.1029/96GL00420 en eng Wiley-Blackwell Geophysical Research Letters;23(5) Bjarnason, I. T., Wolfe, C. J., Solomon, S. C., & Gudmundson, G. (1996). Initial results from the ICEMELT Experiment: Body-wave delay times and shear-wave splitting across Iceland. Geophysical Research Letters, 23(5), 459-462. doi:10.1029/96GL00420 0094-8276 1944-8007 (eISSN) https://hdl.handle.net/20.500.11815/496 Geophysical Research Letters doi:10.1029/96GL00420 info:eu-repo/semantics/openAccess Geophysics Iceland Hotspot Shear-wave Splitting Low-velocity anomaly Upper Mantle Jarðfræði Jarðeðlisfræði Jarðskjálftar Bylgjufræði Mælingar info:eu-repo/semantics/article 1996 ftopinvisindi https://doi.org/20.500.11815/49610.1029/96GL00420 2024-07-09T03:01:56Z We present results from the first stage of the ICEMELT broadband seismometer experiment designed to determine upper mantle structure beneath Iceland, a hotspot located on the Mid-Atlantic Ridge. Relative delays of teleseismic body waves across Iceland are in excess of l s for P waves and as large as 3 s for S waves. The patterns of P and S wave delays suggest a low-velocity anomaly in the upper few hundred kilometers beneath central Iceland, consistent with the signature of mantle upwelling beneath a hotspot. Shear-wave splitting measurements of the fast polarization direction ϕ and the delay time δt between the fast and slow shear waves have been obtained at several network stations. Splitting times range from 0.7 to 1.7 s, and fast directions are generally between N20°W and N45°W. While splitting times of this magnitude must be primarily signatures of the anisotropy of the Icelandic upper mantle, the directions of fast polarization are inconsistent with simple models of horizontally diverging flow either in the plate spreading direction or radially from the center of the hotspot. A hypothesis consistent with splitting data obtained to date is that the dominant contribution to upper mantle anisotropy is from the large-scale mantle flow field of the North Atlantic. National Science Foundation (USA): EAR-9316137 Peer Reviewed Article in Journal/Newspaper Iceland North Atlantic Opin vísindi (Iceland) Geophysical Research Letters 23 5 459 462 |
institution |
Open Polar |
collection |
Opin vísindi (Iceland) |
op_collection_id |
ftopinvisindi |
language |
English |
topic |
Geophysics Iceland Hotspot Shear-wave Splitting Low-velocity anomaly Upper Mantle Jarðfræði Jarðeðlisfræði Jarðskjálftar Bylgjufræði Mælingar |
spellingShingle |
Geophysics Iceland Hotspot Shear-wave Splitting Low-velocity anomaly Upper Mantle Jarðfræði Jarðeðlisfræði Jarðskjálftar Bylgjufræði Mælingar Bjarnason, Ingi Þorleifur Wolfe, Cecily J. Solomon, Sean C. Guðmundsson, Gunnar Initial results from the ICEMELT Experiment: Body-wave delay times and shear-wave splitting across Iceland |
topic_facet |
Geophysics Iceland Hotspot Shear-wave Splitting Low-velocity anomaly Upper Mantle Jarðfræði Jarðeðlisfræði Jarðskjálftar Bylgjufræði Mælingar |
description |
We present results from the first stage of the ICEMELT broadband seismometer experiment designed to determine upper mantle structure beneath Iceland, a hotspot located on the Mid-Atlantic Ridge. Relative delays of teleseismic body waves across Iceland are in excess of l s for P waves and as large as 3 s for S waves. The patterns of P and S wave delays suggest a low-velocity anomaly in the upper few hundred kilometers beneath central Iceland, consistent with the signature of mantle upwelling beneath a hotspot. Shear-wave splitting measurements of the fast polarization direction ϕ and the delay time δt between the fast and slow shear waves have been obtained at several network stations. Splitting times range from 0.7 to 1.7 s, and fast directions are generally between N20°W and N45°W. While splitting times of this magnitude must be primarily signatures of the anisotropy of the Icelandic upper mantle, the directions of fast polarization are inconsistent with simple models of horizontally diverging flow either in the plate spreading direction or radially from the center of the hotspot. A hypothesis consistent with splitting data obtained to date is that the dominant contribution to upper mantle anisotropy is from the large-scale mantle flow field of the North Atlantic. National Science Foundation (USA): EAR-9316137 Peer Reviewed |
author2 |
Raunvísindastofnun (HÍ) Science Institute (UI) Verkfræði- og náttúruvísindasvið (HÍ) School of Engineering and Natural Sciences (UI) Háskóli Íslands University of Iceland |
format |
Article in Journal/Newspaper |
author |
Bjarnason, Ingi Þorleifur Wolfe, Cecily J. Solomon, Sean C. Guðmundsson, Gunnar |
author_facet |
Bjarnason, Ingi Þorleifur Wolfe, Cecily J. Solomon, Sean C. Guðmundsson, Gunnar |
author_sort |
Bjarnason, Ingi Þorleifur |
title |
Initial results from the ICEMELT Experiment: Body-wave delay times and shear-wave splitting across Iceland |
title_short |
Initial results from the ICEMELT Experiment: Body-wave delay times and shear-wave splitting across Iceland |
title_full |
Initial results from the ICEMELT Experiment: Body-wave delay times and shear-wave splitting across Iceland |
title_fullStr |
Initial results from the ICEMELT Experiment: Body-wave delay times and shear-wave splitting across Iceland |
title_full_unstemmed |
Initial results from the ICEMELT Experiment: Body-wave delay times and shear-wave splitting across Iceland |
title_sort |
initial results from the icemelt experiment: body-wave delay times and shear-wave splitting across iceland |
publisher |
Wiley-Blackwell |
publishDate |
1996 |
url |
https://hdl.handle.net/20.500.11815/496 https://doi.org/10.1029/96GL00420 |
genre |
Iceland North Atlantic |
genre_facet |
Iceland North Atlantic |
op_relation |
Geophysical Research Letters;23(5) Bjarnason, I. T., Wolfe, C. J., Solomon, S. C., & Gudmundson, G. (1996). Initial results from the ICEMELT Experiment: Body-wave delay times and shear-wave splitting across Iceland. Geophysical Research Letters, 23(5), 459-462. doi:10.1029/96GL00420 0094-8276 1944-8007 (eISSN) https://hdl.handle.net/20.500.11815/496 Geophysical Research Letters doi:10.1029/96GL00420 |
op_rights |
info:eu-repo/semantics/openAccess |
op_doi |
https://doi.org/20.500.11815/49610.1029/96GL00420 |
container_title |
Geophysical Research Letters |
container_volume |
23 |
container_issue |
5 |
container_start_page |
459 |
op_container_end_page |
462 |
_version_ |
1810450826094706688 |