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...
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Online Access: | https://doi.org/10.1002/2016JF003971 |
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ftcaltechauth:oai:authors.library.caltech.edu:7xeyj-8j091 2024-06-23T07:46:48+00:00 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 https://doi.org/10.1002/2016JF003971 unknown American Geophysical Union https://doi.org/10.1002/2016JF003971 oai:authors.library.caltech.edu:7xeyj-8j091 eprintid:72283 resolverid:CaltechAUTHORS:20161123-141844145 info:eu-repo/semantics/openAccess Other Journal of Geophysical Research. Earth Surface, 122(1), 167-190, (2017-01) synthetic aperture radar glacier mechanics ice-ocean interactions ice shelf buttressing ice-bed mechanics ice rheology info:eu-repo/semantics/article 2017 ftcaltechauth https://doi.org/10.1002/2016JF003971 2024-06-12T06:27:06Z 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. © 2016. American Geophysical Union. Issue online: 17 February 2017; Version of record online: 13 January 2017; Accepted manuscript online: 22 November 2016; Manuscript Accepted: 18 November 2016; Manuscript Revised: 5 October 2016; Manuscript Received: 27 May 2016. We thank E. Smith and A. Smith for providing the seismic data and we benefitted from conversations with H. Gudmundsson, H. Martens, V. Tsai, J.Thompson, and P. Agram. B.M. was partially funded by NASA Cyospheric Sciences award ... 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 |
institution |
Open Polar |
collection |
Caltech Authors (California Institute of Technology) |
op_collection_id |
ftcaltechauth |
language |
unknown |
topic |
synthetic aperture radar glacier mechanics ice-ocean interactions ice shelf buttressing ice-bed mechanics ice rheology |
spellingShingle |
synthetic aperture radar glacier mechanics ice-ocean interactions ice shelf buttressing ice-bed mechanics ice rheology 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 |
topic_facet |
synthetic aperture radar glacier mechanics ice-ocean interactions ice shelf buttressing ice-bed mechanics ice rheology |
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. © 2016. American Geophysical Union. Issue online: 17 February 2017; Version of record online: 13 January 2017; Accepted manuscript online: 22 November 2016; Manuscript Accepted: 18 November 2016; Manuscript Revised: 5 October 2016; Manuscript Received: 27 May 2016. We thank E. Smith and A. Smith for providing the seismic data and we benefitted from conversations with H. Gudmundsson, H. Martens, V. Tsai, J.Thompson, and P. Agram. B.M. was partially funded by NASA Cyospheric Sciences award ... |
format |
Article in Journal/Newspaper |
author |
Minchew, B. M. Simons, M. Riel, B. Milillo, P. |
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://doi.org/10.1002/2016JF003971 |
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_source |
Journal of Geophysical Research. Earth Surface, 122(1), 167-190, (2017-01) |
op_relation |
https://doi.org/10.1002/2016JF003971 oai:authors.library.caltech.edu:7xeyj-8j091 eprintid:72283 resolverid:CaltechAUTHORS:20161123-141844145 |
op_rights |
info:eu-repo/semantics/openAccess 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_ |
1802648338758107136 |