Near-surface seismic anisotropy in Antarctic glacial snow and ice revealed by high-frequency ambient noise
Ambient seismic recordings taken at broad locations across Ross Ice Shelf and a dense array near West Antarctic Ice Sheet (WAIS) Divide, Antarctica, show pervasive temporally variable resonance peaks associated with trapped seismic waves in near-surface firn layers. These resonance peaks feature spl...
| Main Authors: | , , , , , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
Cambridge University Press
2023-08-01
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| Series: | Journal of Glaciology |
| Subjects: | |
| Online Access: | https://www.cambridge.org/core/product/identifier/S0022143022000983/type/journal_article |
| _version_ | 1797770550409428992 |
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| author | Julien Chaput Rick Aster Marianne Karplus Nori Nakata P. Gerstoft P. D. Bromirski A. Nyblade R. A. Stephen D. A. Wiens |
| author_facet | Julien Chaput Rick Aster Marianne Karplus Nori Nakata P. Gerstoft P. D. Bromirski A. Nyblade R. A. Stephen D. A. Wiens |
| author_sort | Julien Chaput |
| collection | DOAJ |
| description | Ambient seismic recordings taken at broad locations across Ross Ice Shelf and a dense array near West Antarctic Ice Sheet (WAIS) Divide, Antarctica, show pervasive temporally variable resonance peaks associated with trapped seismic waves in near-surface firn layers. These resonance peaks feature splitting on the horizontal components, here interpreted as frequency-dependent anisotropy in the firn and underlying ice due to several overlapping mechanisms driven by ice flow. Frequency peak splitting magnitudes and fast/slow axes were systematically estimated at single stations using a novel algorithm and compared with good agreement with active source anisotropy measurements at WAIS Divide determined via active sources recorded on a 1 km circular array. The approach was further applied to the broad Ross Ice Shelf (RIS) array, where anisotropy axes were directly compared with visible surface features and ice shelf flow lines. The near-surface firn, depicted by anisotropy above 30 Hz, was shown to exhibit a novel plastic stretching mechanism of anisotropy, whereby the fast direction in snow aligns with accelerating ice shelf flow. |
| first_indexed | 2024-03-12T21:23:49Z |
| format | Article |
| id | doaj.art-8d12dd15a761486b955be140bbbc3129 |
| institution | Directory Open Access Journal |
| issn | 0022-1430 1727-5652 |
| language | English |
| last_indexed | 2024-03-12T21:23:49Z |
| publishDate | 2023-08-01 |
| publisher | Cambridge University Press |
| record_format | Article |
| series | Journal of Glaciology |
| spelling | doaj.art-8d12dd15a761486b955be140bbbc31292023-07-28T10:47:45ZengCambridge University PressJournal of Glaciology0022-14301727-56522023-08-016977378910.1017/jog.2022.98Near-surface seismic anisotropy in Antarctic glacial snow and ice revealed by high-frequency ambient noiseJulien Chaput0Rick Aster1Marianne Karplus2Nori Nakata3P. Gerstoft4P. D. Bromirski5A. Nyblade6R. A. Stephen7D. A. Wiens8Department of Earth, Environmental, and Resource Sciences, University of Texas at El Paso, El Paso, TX, USADepartment of Geosciences and Warner College of Natural Resources, Colorado State University, Fort Collins, CO, USADepartment of Earth, Environmental, and Resource Sciences, University of Texas at El Paso, El Paso, TX, USADepartment of Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology, Boston, MA, USAScripps Institution of Oceanography, University of California, San Diego, La Jolla, CA, USAScripps Institution of Oceanography, University of California, San Diego, La Jolla, CA, USADepartment of Geosciences, Pennsylvania State University, State College, PA, USAWoods Hole Oceanographic Institution, Woods Hole, MA, USADepartment of Earth and Planetary Sciences, Washington University in St. Louis, St. Louis, MO, USAAmbient seismic recordings taken at broad locations across Ross Ice Shelf and a dense array near West Antarctic Ice Sheet (WAIS) Divide, Antarctica, show pervasive temporally variable resonance peaks associated with trapped seismic waves in near-surface firn layers. These resonance peaks feature splitting on the horizontal components, here interpreted as frequency-dependent anisotropy in the firn and underlying ice due to several overlapping mechanisms driven by ice flow. Frequency peak splitting magnitudes and fast/slow axes were systematically estimated at single stations using a novel algorithm and compared with good agreement with active source anisotropy measurements at WAIS Divide determined via active sources recorded on a 1 km circular array. The approach was further applied to the broad Ross Ice Shelf (RIS) array, where anisotropy axes were directly compared with visible surface features and ice shelf flow lines. The near-surface firn, depicted by anisotropy above 30 Hz, was shown to exhibit a novel plastic stretching mechanism of anisotropy, whereby the fast direction in snow aligns with accelerating ice shelf flow.https://www.cambridge.org/core/product/identifier/S0022143022000983/type/journal_articleIce/atmosphere interactionsseismologysnow |
| spellingShingle | Julien Chaput Rick Aster Marianne Karplus Nori Nakata P. Gerstoft P. D. Bromirski A. Nyblade R. A. Stephen D. A. Wiens Near-surface seismic anisotropy in Antarctic glacial snow and ice revealed by high-frequency ambient noise Journal of Glaciology Ice/atmosphere interactions seismology snow |
| title | Near-surface seismic anisotropy in Antarctic glacial snow and ice revealed by high-frequency ambient noise |
| title_full | Near-surface seismic anisotropy in Antarctic glacial snow and ice revealed by high-frequency ambient noise |
| title_fullStr | Near-surface seismic anisotropy in Antarctic glacial snow and ice revealed by high-frequency ambient noise |
| title_full_unstemmed | Near-surface seismic anisotropy in Antarctic glacial snow and ice revealed by high-frequency ambient noise |
| title_short | Near-surface seismic anisotropy in Antarctic glacial snow and ice revealed by high-frequency ambient noise |
| title_sort | near surface seismic anisotropy in antarctic glacial snow and ice revealed by high frequency ambient noise |
| topic | Ice/atmosphere interactions seismology snow |
| url | https://www.cambridge.org/core/product/identifier/S0022143022000983/type/journal_article |
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