Tidally induced variations in vertical and horizontal motion on Rutford Ice Stream, West Antarctica, inferred from remotely sensed observations
To better understand the influence of stress changes over floating ice shelves on grounded ice streams, we develop a Bayesian method for inferring time-dependent 3-D surface velocity fields from synthetic aperture radar (SAR) and optical remote sensing data. Our specific goal is to observe ocean tid...
Published in: | Journal of Geophysical Research: Earth Surface |
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American Geophysical Union
2017
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ftcaltechauth:oai:authors.library.caltech.edu:72283 2023-05-15T13:55:46+02:00 Tidally induced variations in vertical and horizontal motion on Rutford Ice Stream, West Antarctica, inferred from remotely sensed observations Minchew, B. M. Simons, M. Riel, B. Milillo, P. 2017-01 application/pdf https://authors.library.caltech.edu/72283/ https://authors.library.caltech.edu/72283/3/Minchew_et_al-2017-Journal_of_Geophysical_Research-_Earth_Surface.pdf https://authors.library.caltech.edu/72283/2/JGRF.sup-1.pdf https://resolver.caltech.edu/CaltechAUTHORS:20161123-141844145 en eng American Geophysical Union https://authors.library.caltech.edu/72283/3/Minchew_et_al-2017-Journal_of_Geophysical_Research-_Earth_Surface.pdf https://authors.library.caltech.edu/72283/2/JGRF.sup-1.pdf Minchew, B. M. and Simons, M. and Riel, B. and Milillo, P. (2017) Tidally induced variations in vertical and horizontal motion on Rutford Ice Stream, West Antarctica, inferred from remotely sensed observations. Journal of Geophysical Research. Earth Surface, 122 (1). pp. 167-190. ISSN 2169-9003. doi:10.1002/2016JF003971. https://resolver.caltech.edu/CaltechAUTHORS:20161123-141844145 <https://resolver.caltech.edu/CaltechAUTHORS:20161123-141844145> other Article PeerReviewed 2017 ftcaltechauth https://doi.org/10.1002/2016JF003971 2021-11-18T18:39:52Z To better understand the influence of stress changes over floating ice shelves on grounded ice streams, we develop a Bayesian method for inferring time-dependent 3-D surface velocity fields from synthetic aperture radar (SAR) and optical remote sensing data. Our specific goal is to observe ocean tide-induced variability in vertical ice shelf position and horizontal ice stream flow. Thus, we consider the special case where observed surface displacement at a given location can be defined by a 3-D secular velocity vector, a family of 3-D sinusoidal functions, and a correction to the digital elevation model used to process the SAR data. Using nearly 9 months of SAR data collected from multiple satellite viewing geometries with the COSMO-SkyMed 4-satellite constellation, we infer the spatiotemporal response of Rutford Ice Stream, West Antarctica, to ocean tidal forcing. Consistent with expected tidal uplift, inferred vertical motion over the ice shelf is dominated by semidiurnal and diurnal tidal constituents. Horizontal ice flow variability, on the other hand, occurs primarily at the fortnightly spring-neap tidal period (M_(sf)). We propose that periodic grounding of the ice shelf is the primary mechanism for translating vertical tidal motion into horizontal flow variability, causing ice flow to accelerate first and most strongly over the ice shelf. Flow variations then propagate through the grounded ice stream at a mean rate of ∼29 km/d and decay quasi-linearly with distance over ∼85 km upstream of the grounding zone. Article in Journal/Newspaper Antarc* Antarctica Ice Shelf Ice Shelves Rutford Ice Stream West Antarctica Caltech Authors (California Institute of Technology) Rutford ENVELOPE(-85.300,-85.300,-78.600,-78.600) Rutford Ice Stream ENVELOPE(-80.000,-80.000,-79.167,-79.167) West Antarctica Journal of Geophysical Research: Earth Surface 122 1 167 190 |
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Open Polar |
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Caltech Authors (California Institute of Technology) |
op_collection_id |
ftcaltechauth |
language |
English |
description |
To better understand the influence of stress changes over floating ice shelves on grounded ice streams, we develop a Bayesian method for inferring time-dependent 3-D surface velocity fields from synthetic aperture radar (SAR) and optical remote sensing data. Our specific goal is to observe ocean tide-induced variability in vertical ice shelf position and horizontal ice stream flow. Thus, we consider the special case where observed surface displacement at a given location can be defined by a 3-D secular velocity vector, a family of 3-D sinusoidal functions, and a correction to the digital elevation model used to process the SAR data. Using nearly 9 months of SAR data collected from multiple satellite viewing geometries with the COSMO-SkyMed 4-satellite constellation, we infer the spatiotemporal response of Rutford Ice Stream, West Antarctica, to ocean tidal forcing. Consistent with expected tidal uplift, inferred vertical motion over the ice shelf is dominated by semidiurnal and diurnal tidal constituents. Horizontal ice flow variability, on the other hand, occurs primarily at the fortnightly spring-neap tidal period (M_(sf)). We propose that periodic grounding of the ice shelf is the primary mechanism for translating vertical tidal motion into horizontal flow variability, causing ice flow to accelerate first and most strongly over the ice shelf. Flow variations then propagate through the grounded ice stream at a mean rate of ∼29 km/d and decay quasi-linearly with distance over ∼85 km upstream of the grounding zone. |
format |
Article in Journal/Newspaper |
author |
Minchew, B. M. Simons, M. Riel, B. Milillo, P. |
spellingShingle |
Minchew, B. M. Simons, M. Riel, B. Milillo, P. Tidally induced variations in vertical and horizontal motion on Rutford Ice Stream, West Antarctica, inferred from remotely sensed observations |
author_facet |
Minchew, B. M. Simons, M. Riel, B. Milillo, P. |
author_sort |
Minchew, B. M. |
title |
Tidally induced variations in vertical and horizontal motion on Rutford Ice Stream, West Antarctica, inferred from remotely sensed observations |
title_short |
Tidally induced variations in vertical and horizontal motion on Rutford Ice Stream, West Antarctica, inferred from remotely sensed observations |
title_full |
Tidally induced variations in vertical and horizontal motion on Rutford Ice Stream, West Antarctica, inferred from remotely sensed observations |
title_fullStr |
Tidally induced variations in vertical and horizontal motion on Rutford Ice Stream, West Antarctica, inferred from remotely sensed observations |
title_full_unstemmed |
Tidally induced variations in vertical and horizontal motion on Rutford Ice Stream, West Antarctica, inferred from remotely sensed observations |
title_sort |
tidally induced variations in vertical and horizontal motion on rutford ice stream, west antarctica, inferred from remotely sensed observations |
publisher |
American Geophysical Union |
publishDate |
2017 |
url |
https://authors.library.caltech.edu/72283/ https://authors.library.caltech.edu/72283/3/Minchew_et_al-2017-Journal_of_Geophysical_Research-_Earth_Surface.pdf https://authors.library.caltech.edu/72283/2/JGRF.sup-1.pdf https://resolver.caltech.edu/CaltechAUTHORS:20161123-141844145 |
long_lat |
ENVELOPE(-85.300,-85.300,-78.600,-78.600) ENVELOPE(-80.000,-80.000,-79.167,-79.167) |
geographic |
Rutford Rutford Ice Stream West Antarctica |
geographic_facet |
Rutford Rutford Ice Stream West Antarctica |
genre |
Antarc* Antarctica Ice Shelf Ice Shelves Rutford Ice Stream West Antarctica |
genre_facet |
Antarc* Antarctica Ice Shelf Ice Shelves Rutford Ice Stream West Antarctica |
op_relation |
https://authors.library.caltech.edu/72283/3/Minchew_et_al-2017-Journal_of_Geophysical_Research-_Earth_Surface.pdf https://authors.library.caltech.edu/72283/2/JGRF.sup-1.pdf Minchew, B. M. and Simons, M. and Riel, B. and Milillo, P. (2017) Tidally induced variations in vertical and horizontal motion on Rutford Ice Stream, West Antarctica, inferred from remotely sensed observations. Journal of Geophysical Research. Earth Surface, 122 (1). pp. 167-190. ISSN 2169-9003. doi:10.1002/2016JF003971. https://resolver.caltech.edu/CaltechAUTHORS:20161123-141844145 <https://resolver.caltech.edu/CaltechAUTHORS:20161123-141844145> |
op_rights |
other |
op_doi |
https://doi.org/10.1002/2016JF003971 |
container_title |
Journal of Geophysical Research: Earth Surface |
container_volume |
122 |
container_issue |
1 |
container_start_page |
167 |
op_container_end_page |
190 |
_version_ |
1766262600695283712 |