Crustal attenuation from USArray ML amplitude tomography
SUMMARY Seismic attenuation across the US is estimated using station ML magnitude data from the USArray. Station magnitudes are recalibrated back to amplitude and back projected in a 2-D tomography. Data represent the amplitudes of the horizontal components of the Lg phase. The western US shows regi...
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croxfordunivpr:10.1093/gji/ggaa445 2024-03-03T08:47:16+00:00 Crustal attenuation from USArray ML amplitude tomography Hearn, Thomas M 2020 http://dx.doi.org/10.1093/gji/ggaa445 http://academic.oup.com/gji/advance-article-pdf/doi/10.1093/gji/ggaa445/33773676/ggaa445.pdf http://academic.oup.com/gji/article-pdf/224/1/199/34193188/ggaa445.pdf en eng Oxford University Press (OUP) https://academic.oup.com/journals/pages/open_access/funder_policies/chorus/standard_publication_model Geophysical Journal International volume 224, issue 1, page 199-206 ISSN 0956-540X 1365-246X Geochemistry and Petrology Geophysics journal-article 2020 croxfordunivpr https://doi.org/10.1093/gji/ggaa445 2024-02-05T10:31:46Z SUMMARY Seismic attenuation across the US is estimated using station ML magnitude data from the USArray. Station magnitudes are recalibrated back to amplitude and back projected in a 2-D tomography. Data represent the amplitudes of the horizontal components of the Lg phase. The western US shows regions of very high attenuation and contrasts with the lesser attenuation of the eastern US. Individual attenuation anomalies can be clearly tied to regional geology. Station gains show broad regional variations that match geographic regions. Most of the high-attenuation areas are regions of high geothermal activity suggesting that intrinsic attenuation dominates over scattering attenuation. An exception is the central San Andreas Fault zone because it lacks any localized heat-flow anomaly. The US east of the Rocky Mountains is bland and contains none of the high-attenuation regions of the western US. Instead, the central US has low-attenuation patches that do not obviously correspond to geologic province. Sediments of the Gulf Coast Plain, Willison Basin and Michigan Basin do show up as intermediate attenuation while the Illinois Basin, Appalachian Basin and other basins are not apparent. In Alaska, attenuation is generally less than the western US, but still much greater than the eastern US. In southeast Alaska, the Wrangell Volcanic Field causes a sizeable high-attenuation zone. The volcanic Aleutian Mountains also have high attenuation. However, moderate to high attenuation also correlates with the tertiary sedimentary basins in Alaska. The North Slope Basin does not seem to attenuate. Thicker crust and mountain roots tend to show less attenuation, if anything, but this correspondence is most likely due to differences in temperature and seismic velocity. Heat, scattering and young sedimentary basins create seismic attenuation in the continental crust. Article in Journal/Newspaper north slope Alaska Oxford University Press Andreas ENVELOPE(-60.729,-60.729,-64.008,-64.008) Geophysical Journal International 224 1 199 206 |
institution |
Open Polar |
collection |
Oxford University Press |
op_collection_id |
croxfordunivpr |
language |
English |
topic |
Geochemistry and Petrology Geophysics |
spellingShingle |
Geochemistry and Petrology Geophysics Hearn, Thomas M Crustal attenuation from USArray ML amplitude tomography |
topic_facet |
Geochemistry and Petrology Geophysics |
description |
SUMMARY Seismic attenuation across the US is estimated using station ML magnitude data from the USArray. Station magnitudes are recalibrated back to amplitude and back projected in a 2-D tomography. Data represent the amplitudes of the horizontal components of the Lg phase. The western US shows regions of very high attenuation and contrasts with the lesser attenuation of the eastern US. Individual attenuation anomalies can be clearly tied to regional geology. Station gains show broad regional variations that match geographic regions. Most of the high-attenuation areas are regions of high geothermal activity suggesting that intrinsic attenuation dominates over scattering attenuation. An exception is the central San Andreas Fault zone because it lacks any localized heat-flow anomaly. The US east of the Rocky Mountains is bland and contains none of the high-attenuation regions of the western US. Instead, the central US has low-attenuation patches that do not obviously correspond to geologic province. Sediments of the Gulf Coast Plain, Willison Basin and Michigan Basin do show up as intermediate attenuation while the Illinois Basin, Appalachian Basin and other basins are not apparent. In Alaska, attenuation is generally less than the western US, but still much greater than the eastern US. In southeast Alaska, the Wrangell Volcanic Field causes a sizeable high-attenuation zone. The volcanic Aleutian Mountains also have high attenuation. However, moderate to high attenuation also correlates with the tertiary sedimentary basins in Alaska. The North Slope Basin does not seem to attenuate. Thicker crust and mountain roots tend to show less attenuation, if anything, but this correspondence is most likely due to differences in temperature and seismic velocity. Heat, scattering and young sedimentary basins create seismic attenuation in the continental crust. |
format |
Article in Journal/Newspaper |
author |
Hearn, Thomas M |
author_facet |
Hearn, Thomas M |
author_sort |
Hearn, Thomas M |
title |
Crustal attenuation from USArray ML amplitude tomography |
title_short |
Crustal attenuation from USArray ML amplitude tomography |
title_full |
Crustal attenuation from USArray ML amplitude tomography |
title_fullStr |
Crustal attenuation from USArray ML amplitude tomography |
title_full_unstemmed |
Crustal attenuation from USArray ML amplitude tomography |
title_sort |
crustal attenuation from usarray ml amplitude tomography |
publisher |
Oxford University Press (OUP) |
publishDate |
2020 |
url |
http://dx.doi.org/10.1093/gji/ggaa445 http://academic.oup.com/gji/advance-article-pdf/doi/10.1093/gji/ggaa445/33773676/ggaa445.pdf http://academic.oup.com/gji/article-pdf/224/1/199/34193188/ggaa445.pdf |
long_lat |
ENVELOPE(-60.729,-60.729,-64.008,-64.008) |
geographic |
Andreas |
geographic_facet |
Andreas |
genre |
north slope Alaska |
genre_facet |
north slope Alaska |
op_source |
Geophysical Journal International volume 224, issue 1, page 199-206 ISSN 0956-540X 1365-246X |
op_rights |
https://academic.oup.com/journals/pages/open_access/funder_policies/chorus/standard_publication_model |
op_doi |
https://doi.org/10.1093/gji/ggaa445 |
container_title |
Geophysical Journal International |
container_volume |
224 |
container_issue |
1 |
container_start_page |
199 |
op_container_end_page |
206 |
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1792503419038072832 |