Seismic Short-Refraction Studies on the Ross Ice Shelf, Antarctica
Abstract Seismic short-refraction studies were carried out at five stations on the Ross Ice Shelf during the 1976–77 summer season as part of the comprehensive Ross Ice Shelf Geophysical and Glaciological Survey. Measurements of the velocities of compressional waves were made at each location. Compr...
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Cambridge University Press (CUP)
1979
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Online Access: | http://dx.doi.org/10.1017/s0022143000014830 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0022143000014830 |
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crcambridgeupr:10.1017/s0022143000014830 2024-03-03T08:38:54+00:00 Seismic Short-Refraction Studies on the Ross Ice Shelf, Antarctica Kirchner, Joseph F. Bentley, Charles R. 1979 http://dx.doi.org/10.1017/s0022143000014830 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0022143000014830 en eng Cambridge University Press (CUP) Journal of Glaciology volume 24, issue 90, page 313-319 ISSN 0022-1430 1727-5652 Earth-Surface Processes journal-article 1979 crcambridgeupr https://doi.org/10.1017/s0022143000014830 2024-02-08T08:38:15Z Abstract Seismic short-refraction studies were carried out at five stations on the Ross Ice Shelf during the 1976–77 summer season as part of the comprehensive Ross Ice Shelf Geophysical and Glaciological Survey. Measurements of the velocities of compressional waves were made at each location. Compressional wave velocities were measured along more than one azimuth at three sites, and shear wave velocities (both components) at two. Travel-time curves were fitted to an exponential expression by means of a non-linear least-squares regression technique. The errors in the apparent velocities are estimated to be about ±50 m s –1 at short distances, diminishing to about ±10 m s –1 near the ends of the profiles. Compressional-wave velocities show only slight variations with azimuth and only over certain depth intervals, showing that constant-velocity surfaces are essentially horizontal. Shear-wave velocities, however, exhibit large variations according to azimuth and polarization, indicating that transverse isotropy is violated at least in the upper 30–40 m of the ice shelf. It is believed that the anisotropy is caused by structural details in the firn perhaps modified by preferred crystal orientation and that it may arise at least partly from anisotropic stresses in the ice shelf. Article in Journal/Newspaper Antarc* Antarctica Ice Shelf Journal of Glaciology Ross Ice Shelf Cambridge University Press Ross Ice Shelf Journal of Glaciology 24 90 313 319 |
institution |
Open Polar |
collection |
Cambridge University Press |
op_collection_id |
crcambridgeupr |
language |
English |
topic |
Earth-Surface Processes |
spellingShingle |
Earth-Surface Processes Kirchner, Joseph F. Bentley, Charles R. Seismic Short-Refraction Studies on the Ross Ice Shelf, Antarctica |
topic_facet |
Earth-Surface Processes |
description |
Abstract Seismic short-refraction studies were carried out at five stations on the Ross Ice Shelf during the 1976–77 summer season as part of the comprehensive Ross Ice Shelf Geophysical and Glaciological Survey. Measurements of the velocities of compressional waves were made at each location. Compressional wave velocities were measured along more than one azimuth at three sites, and shear wave velocities (both components) at two. Travel-time curves were fitted to an exponential expression by means of a non-linear least-squares regression technique. The errors in the apparent velocities are estimated to be about ±50 m s –1 at short distances, diminishing to about ±10 m s –1 near the ends of the profiles. Compressional-wave velocities show only slight variations with azimuth and only over certain depth intervals, showing that constant-velocity surfaces are essentially horizontal. Shear-wave velocities, however, exhibit large variations according to azimuth and polarization, indicating that transverse isotropy is violated at least in the upper 30–40 m of the ice shelf. It is believed that the anisotropy is caused by structural details in the firn perhaps modified by preferred crystal orientation and that it may arise at least partly from anisotropic stresses in the ice shelf. |
format |
Article in Journal/Newspaper |
author |
Kirchner, Joseph F. Bentley, Charles R. |
author_facet |
Kirchner, Joseph F. Bentley, Charles R. |
author_sort |
Kirchner, Joseph F. |
title |
Seismic Short-Refraction Studies on the Ross Ice Shelf, Antarctica |
title_short |
Seismic Short-Refraction Studies on the Ross Ice Shelf, Antarctica |
title_full |
Seismic Short-Refraction Studies on the Ross Ice Shelf, Antarctica |
title_fullStr |
Seismic Short-Refraction Studies on the Ross Ice Shelf, Antarctica |
title_full_unstemmed |
Seismic Short-Refraction Studies on the Ross Ice Shelf, Antarctica |
title_sort |
seismic short-refraction studies on the ross ice shelf, antarctica |
publisher |
Cambridge University Press (CUP) |
publishDate |
1979 |
url |
http://dx.doi.org/10.1017/s0022143000014830 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0022143000014830 |
geographic |
Ross Ice Shelf |
geographic_facet |
Ross Ice Shelf |
genre |
Antarc* Antarctica Ice Shelf Journal of Glaciology Ross Ice Shelf |
genre_facet |
Antarc* Antarctica Ice Shelf Journal of Glaciology Ross Ice Shelf |
op_source |
Journal of Glaciology volume 24, issue 90, page 313-319 ISSN 0022-1430 1727-5652 |
op_doi |
https://doi.org/10.1017/s0022143000014830 |
container_title |
Journal of Glaciology |
container_volume |
24 |
container_issue |
90 |
container_start_page |
313 |
op_container_end_page |
319 |
_version_ |
1792507393755578368 |