Abstract:
This dataset provides a geopackage of the predicted subglacial water flow pathways beneath Whillans Ice Plain, West Antarctica, the contributory Whillans Ice Stream and neighbouring Kamb and Mercer Ice Streams. Flow paths were estimated based on hydropotential gradients using static grids of ice-surface elevation from the REMA mosaic (Howat and others, 2019) and ice thickness from Bedmachine Antarctica version 3 (Morlighem and others, 2020; 2022) from which bed elevation is inferred.
Wilson Sauthoff (dataset creator) was funded by NASA award 80NSSC21K0912.
Bryony I. D. Freer (project lead) was supported by Natural Environment Research Council (NERC) Satellite Data in Environmental Science (SENSE) Centre for Doctoral Training (grant no. NE/T00939X/1).
Keywords:
Antarctica, Engelhardt Subglacial Lake, Siple Coast, Subglacial hydrology, Whillans Ice Plain, flow paths, subglacial lakes
Sauthoff, W., & Freer, B. (2024). Subglacial water flow paths beneath Whillans Ice Plain, West Antarctica (Version 1.0) [Data set]. NERC EDS UK Polar Data Centre. https://doi.org/10.5285/0df5d4e9-2fcd-4420-b403-24d76848a5a5
| Access Constraints: | None |
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| Use Constraints: | This data is covered by a UK Open Government Licence (http://www.nationalarchives.gov.uk/doc/open-government-licence/version/3/) |
| Creation Date: | 2024-05-31 |
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| Dataset Progress: | Complete |
| Dataset Language: | English |
| ISO Topic Categories: |
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| Parameters: |
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| Personnel: | |
| Name | PDC BAS |
| Role(s) | Metadata Author |
| Organisation | British Antarctic Survey |
| Name | Dr Wilson Sauthoff |
| Role(s) | Investigator |
| Organisation | Colorado School of Mines |
| Name | Ms Bryony Freer |
| Role(s) | Investigator |
| Organisation | British Antarctic Survey |
| Parent Dataset: | N/A |
| Reference: | Main reference: Freer et al. (2024, in review) - full reference tbc upon outcome of review process Lineage reference: Bartos, M. (2020). pysheds: simple and fast watershed delineation in Python. Retrieved from https://github.com/mdbartos/pysheds. https://doi.org/10.5281/zenodo.3822494 Depoorter, M. A., Bamber, J. L., Griggs, J. A., Lenaerts, J. T. M., Ligtenberg, S. R. M., van den Broeke, M. R., & Moholdt, G. (2013). Calving fluxes and basal melt rates of Antarctic ice shelves. Nature, 502(7469), 89-92. https://doi.org/10.1038/nature12567 Howat, I. M., Porter, C., Smith, B. E., Noh, M.-J., & Morin, P. (2019). The Reference Elevation Model of Antarctica. The Cryosphere, 13(2), 665-674. https://doi.org/10.5194/tc-13-665-2019 Morlighem, M., Rignot, E., Binder, T., Blankenship, D., Drews, R., Eagles, G., et al. (2020). Deep glacial troughs and stabilizing ridges unveiled beneath the margins of the Antarctic ice sheet. Nature Geoscience, 13(2), 132-137. https://doi.org/10.1038/s41561-019-0510-8 Morlighem, M. (2022). MEaSUREs BedMachine Antarctica, Version 3 [Data Set]. Boulder, Colorado USA. NASA National Snow and Ice Data Center Distributed Active Archive Center. https://doi.org/10.5067/FPSU0V1MWUB6. Date Accessed 05-25-2024. Mouginot, J., B. Scheuchl, and E. Rignot. (2017). MEaSUREs Antarctic Boundaries for IPY 2007-2009 from Satellite Radar, Version 2 [Data Set]. Boulder, Colorado USA. NASA National Snow and Ice Data Center Distributed Active Archive Center. https://doi.org/10.5067/AXE4121732AD. Date Accessed 05-25-2024. Shreve, R. L. (1972). Movement of Water in Glaciers. Journal of Glaciology, 11(62), 205-214. https://doi.org/10.3189/S002214300002219X Snow, T., Millstein, J., Scheick, J., Sauthoff, W., Leong, W. J., Colliander, J., Pérez, F., Munroe, J., Felikson, D., Sutterley, T., & Siegfried, M. (2023). CryoCloud JupyterBook (2023.01.26). Zenodo. https://doi.org/10.5281/zenodo.7576602. |
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| Quality: | Ice-surface elevations from REMA (Howat and others, 2019) have relatively low error, typically less than 1 m. Sources of error in BedMachine Antarctica's estimates of ice thickness and thus bed elevation include error in ice velocity direction and magnitude, error in surface mass balance, and ice thinning rates. Below grounded ice, the error in mass conservation derived ice thickness and bed elevation ranges from 36 m to exceeding 200 m based on the density radar sounding coverage (Morlighem and others, 2020; 2022). Within the region of subglacial flow path mapping, BedMachine Antarctica has a mean error of 74.8 m and a maximum error of 786.0 m, which is most prominent in the upper catchment of Kamb Ice Stream. | |
| Lineage: | We used static grids of ice surface elevation from the REMA mosaic (Howat and others, 2019) and ice thickness (from which bed elevation is inferred; Morlighem and others, 2020; 2022) to predict the subglacial water flow routing pathways based on hydropotential gradients. Hydropotential gradients control where water is driven to flow by gravitational potential (bed elevation) and ice overburden pressure (Shreve, 1972), given by equation 1: del-phi = rho . g . del-z . del-Pw where phi is the hydropotential gradient, rho is the density of water, g is gravitational acceleration, z is bed elevation, and Pw is water pressure. Pw assumes effective pressure (N) is zero, which is a common assumption in subglacial hydrology where effective pressure is challenging to measure. Instead Pw is calculated solely from the depth of the ice column above. Flow routing pathways were modelled based on the hydropotential surface using the Python package, pysheds release 0.3.5 (Bartos, 2020). We conditioned the hydropotential surface by pit and depression filling and resolved flats. Flow direction and accumulation used the default directional mapping that specifies the routing algorithm. We extracted flow paths with flow accumulations >1,000 upstream cells. Flow paths were clipped at the grounding line (Depoorter and others, 2013) and filtered to only include flow paths intersecting the region of interest (Whillans Ice Plain, West Antarctica, the contributory Whillans Ice Stream and neighbouring Kamb and Mercer Ice Streams). Computation was conducted using a ~32 GB server on CryoCloud cloud-computing hub (Snow and others, 2023). Temporal coverage: * We used static grids of ice surface elevation from BedMachine Antarctica, Version 3 (Morlighem and others, 2020; 2022) that uses the REMA mosaic (Howat and others, 2019), which was created with sub-meter resolution Maxar optical satellite imagery acquired across multiple austral summer seasons between 2009 and 2021. * We used static grids of ice thickness from BedMachine Antarctica, Version 3 (Morlighem and others, 2020; 2022). BedMachine Antarctica uses a variety of input datasets with temporal coverage spanning 1961 to 2020. Location: The dataset covers the region of interest, the Whillans Ice Plain, plus the upstream ice drainage basin of Whillans Ice Stream and neighbouring Kamb and Mercer Ice Streams as defined in the refined basins in the MEaSUREs Antarctic Boundaries for IPY 2007-2009 from Satellite Radar, Version 2 dataset (Mouginot and others, 2017). CRS: Polar stereographic projection (?EPSG:3031?) |
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| Temporal Coverage: | |
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| Start Date | 1961-01-01 |
| End Date | 2021-12-31 |
| Spatial Coverage: | |
| Latitude | |
| Southernmost | -88.3 |
| Northernmost | -79.54 |
| Longitude | |
| Westernmost | -174.33 |
| Easternmost | -97.58 |
| Altitude | |
| Min Altitude | -2446.31 |
| Max Altitude | 3805.99 |
| Depth | |
| Min Depth | N/A |
| Max Depth | N/A |
| Data Resolution: | |
| Latitude Resolution | N/A |
| Longitude Resolution | N/A |
| Horizontal Resolution Range | 500 meters - < 1 km |
| Vertical Resolution | N/A |
| Vertical Resolution Range | N/A |
| Temporal Resolution | N/A |
| Temporal Resolution Range | N/A |
| Location: | |
| Location | Antarctica |
| Detailed Location | Whillans Ice Plain |
| Location | Antarctica |
| Detailed Location | Whillans Ice Stream |
| Location | Antarctica |
| Detailed Location | Kamb and Mercer Ice Streams |
| Data Collection: | To generate the predicted subglacial flow paths, we used the Python package, pysheds release 0.3.5 (Bartos, 2020). |
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| Distribution: | |
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| Distribution Media | Online Internet (HTTP) |
| Distribution Size | 1MB |
| Distribution Format | N/A |
| Fees | N/A |
| Data Storage: | This dataset consists of one geopackage file, that is ~1 MB. |