Reinterpretation of the RRISP-77 Iceland shear-wave profiles
Two shear-wave profiles, E and G, collected during the 1977 Reykjanes Ridge Iceland Seismic Experiment have played an important role in models of the Icelandic crust. They were originally interpreted as indicating very low shear-wave velocities and abnormally low shear-wave quality factors in the 10...
Published in: | Geophysical Journal International |
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Language: | English |
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Oxford University Press (OUP)
1996
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Online Access: | https://hdl.handle.net/20.500.11815/567 https://doi.org/10.1111/j.1365-246X.1996.tb05275.x |
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ftopinvisindi:oai:opinvisindi.is:20.500.11815/567 2024-09-15T18:13:18+00:00 Reinterpretation of the RRISP-77 Iceland shear-wave profiles Menke, William Brandsdóttir, Bryndís Einarsson, Páll Bjarnason, Ingi Þorleifur Raunvísindastofnun (HÍ) Science Institute (UI) Verkfræði- og náttúruvísindasvið (HÍ) School of Engineering and Natural Sciences (UI) Háskóli Íslands University of Iceland 1996-07 166-172 https://hdl.handle.net/20.500.11815/567 https://doi.org/10.1111/j.1365-246X.1996.tb05275.x en eng Oxford University Press (OUP) Geophysical Journal International;126(1) http://academic.oup.com/gji/article-pdf/126/1/166/6043966/126-1-166.pdf Menke, W., Brandsdóttir, B., Einarsson, P. and Bjarnason, I. Th. (1996), Reinterpretation of the RRISP-77 Iceland shear-wave profiles. Geophysical Journal International, 126: 166–172. doi:10.1111/j.1365-246X.1996.tb05275.x 0956-540X 1365-246X (eISSN) https://hdl.handle.net/20.500.11815/567 Geophysical Journal International doi:10.1111/j.1365-246X.1996.tb05275.x info:eu-repo/semantics/openAccess Geophysics Crust Iceland Reykjanes Rigde S waves Jarðeðlisfræði Jarðskorpa Jarðskorpuhreyfingar Bylgjufræði Reykjaneshryggur info:eu-repo/semantics/article 1996 ftopinvisindi https://doi.org/20.500.11815/56710.1111/j.1365-246X.1996.tb05275.x 2024-07-09T03:01:56Z Two shear-wave profiles, E and G, collected during the 1977 Reykjanes Ridge Iceland Seismic Experiment have played an important role in models of the Icelandic crust. They were originally interpreted as indicating very low shear-wave velocities and abnormally low shear-wave quality factors in the 10–15 km depth range. These attributes, which are indicative of near-solidus temperatures, were used to support the hypothesis that the crust of Iceland is relatively thin (10–15 km) and underlain by partially molten material. More recent seismic data, however, contradict this hypothesis and suggest that the crust is thicker (20–30 km) and cooler. A re-examination of the RRISP-77 data indicates that the low shear-wave velocities are artefacts arising from source static anomalies (in the case of profile G) and misidentification of a secondary shear phase, SmS, as S (in the case of profile E). Furthermore, the attenuation occurs at ranges when rays from the shots pass near the Askja (profile E) and Katla and Oraefajokull (profile G) volcanoes. It may therefore have a localized source, and not be diagnostic of Icelandic crust as a whole. This new interpretation of the RRISP-77 shear-wave data is consistent with models having a thick, cold crust. We thank 0. Flovenz, one of the principal investigators of the SIST experiment, G. Foulger and B. Julian, principal investigators of the Hengill experiment, and the Incorporated Research Institutions for Seismology for providing us with copies of the data. Lamont Doherty Contribution Number 5513 Peer Reviewed Article in Journal/Newspaper Iceland Katla Opin vísindi (Iceland) Geophysical Journal International 126 1 166 172 |
institution |
Open Polar |
collection |
Opin vísindi (Iceland) |
op_collection_id |
ftopinvisindi |
language |
English |
topic |
Geophysics Crust Iceland Reykjanes Rigde S waves Jarðeðlisfræði Jarðskorpa Jarðskorpuhreyfingar Bylgjufræði Reykjaneshryggur |
spellingShingle |
Geophysics Crust Iceland Reykjanes Rigde S waves Jarðeðlisfræði Jarðskorpa Jarðskorpuhreyfingar Bylgjufræði Reykjaneshryggur Menke, William Brandsdóttir, Bryndís Einarsson, Páll Bjarnason, Ingi Þorleifur Reinterpretation of the RRISP-77 Iceland shear-wave profiles |
topic_facet |
Geophysics Crust Iceland Reykjanes Rigde S waves Jarðeðlisfræði Jarðskorpa Jarðskorpuhreyfingar Bylgjufræði Reykjaneshryggur |
description |
Two shear-wave profiles, E and G, collected during the 1977 Reykjanes Ridge Iceland Seismic Experiment have played an important role in models of the Icelandic crust. They were originally interpreted as indicating very low shear-wave velocities and abnormally low shear-wave quality factors in the 10–15 km depth range. These attributes, which are indicative of near-solidus temperatures, were used to support the hypothesis that the crust of Iceland is relatively thin (10–15 km) and underlain by partially molten material. More recent seismic data, however, contradict this hypothesis and suggest that the crust is thicker (20–30 km) and cooler. A re-examination of the RRISP-77 data indicates that the low shear-wave velocities are artefacts arising from source static anomalies (in the case of profile G) and misidentification of a secondary shear phase, SmS, as S (in the case of profile E). Furthermore, the attenuation occurs at ranges when rays from the shots pass near the Askja (profile E) and Katla and Oraefajokull (profile G) volcanoes. It may therefore have a localized source, and not be diagnostic of Icelandic crust as a whole. This new interpretation of the RRISP-77 shear-wave data is consistent with models having a thick, cold crust. We thank 0. Flovenz, one of the principal investigators of the SIST experiment, G. Foulger and B. Julian, principal investigators of the Hengill experiment, and the Incorporated Research Institutions for Seismology for providing us with copies of the data. Lamont Doherty Contribution Number 5513 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 |
Menke, William Brandsdóttir, Bryndís Einarsson, Páll Bjarnason, Ingi Þorleifur |
author_facet |
Menke, William Brandsdóttir, Bryndís Einarsson, Páll Bjarnason, Ingi Þorleifur |
author_sort |
Menke, William |
title |
Reinterpretation of the RRISP-77 Iceland shear-wave profiles |
title_short |
Reinterpretation of the RRISP-77 Iceland shear-wave profiles |
title_full |
Reinterpretation of the RRISP-77 Iceland shear-wave profiles |
title_fullStr |
Reinterpretation of the RRISP-77 Iceland shear-wave profiles |
title_full_unstemmed |
Reinterpretation of the RRISP-77 Iceland shear-wave profiles |
title_sort |
reinterpretation of the rrisp-77 iceland shear-wave profiles |
publisher |
Oxford University Press (OUP) |
publishDate |
1996 |
url |
https://hdl.handle.net/20.500.11815/567 https://doi.org/10.1111/j.1365-246X.1996.tb05275.x |
genre |
Iceland Katla |
genre_facet |
Iceland Katla |
op_relation |
Geophysical Journal International;126(1) http://academic.oup.com/gji/article-pdf/126/1/166/6043966/126-1-166.pdf Menke, W., Brandsdóttir, B., Einarsson, P. and Bjarnason, I. Th. (1996), Reinterpretation of the RRISP-77 Iceland shear-wave profiles. Geophysical Journal International, 126: 166–172. doi:10.1111/j.1365-246X.1996.tb05275.x 0956-540X 1365-246X (eISSN) https://hdl.handle.net/20.500.11815/567 Geophysical Journal International doi:10.1111/j.1365-246X.1996.tb05275.x |
op_rights |
info:eu-repo/semantics/openAccess |
op_doi |
https://doi.org/20.500.11815/56710.1111/j.1365-246X.1996.tb05275.x |
container_title |
Geophysical Journal International |
container_volume |
126 |
container_issue |
1 |
container_start_page |
166 |
op_container_end_page |
172 |
_version_ |
1810450964362035200 |