Date (Creation)

2024-05-31

Date (Revision)

2024-05-31

Date (Publication)

2024-05-31

Date (released)

2024-05-31

Edition

1.0

Unique resource identifier

https://doi.org/10.5285/0df5d4e9-2fcd-4420-b403-24d76848a5a5

Codespace

doi

Unique resource identifier

GB/NERC/BAS/PDC/01854

Codespace

https://data.bas.ac.uk/

Unique resource identifier

NE/T00939X/1

Codespace

award

Other citation details

Please cite this item as: 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

Credit

No credit.

Status

Completed

Point of contact

Organisation name	Individual name	Electronic mail address	Role
Colorado School of Mines	Sauthoff, Wilson		Author
British Antarctic Survey	Freer, Bryony		Author
NERC EDS UK Polar Data Centre		PDCServiceDesk@bas.ac.uk	Point of contact

Maintenance and update frequency

As needed

Maintenance note

Completed

Global Change Master Directory (GCMD) Science Keywords

• EARTH SCIENCE > Hydrosphere > Ground Water > Ground Water Discharge/Flow
• EARTH SCIENCE > Cryosphere > Snow/Ice

Theme

• Antarctica

• Engelhardt Subglacial Lake

• Siple Coast

• Subglacial hydrology

• Whillans Ice Plain

• flow paths

• subglacial lakes

Place

• Whillans Ice Plain Antarctica

• Whillans Ice Stream Antarctica

• Kamb and Mercer Ice Streams Antarctica

GEMET - INSPIRE themes, version 1.0

• Hydrography
• Meteorological geographical features

Access constraints

Other restrictions

Other constraints

no limitations to public access

Access constraints

Other restrictions

Other constraints

no limitations

Use constraints

License

Other constraints

Open Government Licence v3.0

Use constraints

Other restrictions

Other constraints

None

Unique resource identifier

doi

Codespace

doi

Association Type

dependency

Unique resource identifier

doi

Codespace

doi

Association Type

Cross reference

Unique resource identifier

doi

Codespace

doi

Association Type

Cross reference

Unique resource identifier

doi

Codespace

doi

Association Type

Cross reference

Unique resource identifier

doi

Codespace

doi

Association Type

Cross reference

Unique resource identifier

doi

Codespace

doi

Association Type

Cross reference

Unique resource identifier

doi

Codespace

doi

Association Type

Cross reference

Unique resource identifier

url

Codespace

url

Association Type

Cross reference

Spatial representation type

Text, table

Language

English

Character set

UTF8

Topic category

• Geoscientific information

Begin date

1961-01-01

End date

2021-12-31

Supplemental Information

It is recommended that careful attention be paid to the contents of any data, and that the author be contacted with any questions regarding appropriate use. If you find any errors or omissions, please report them to polardatacentre@bas.ac.uk.

Title

European Petroleum Survey Group (EPSG) Geodetic Parameter Registry

Date (Publication)

2008-11-12

Cited responsible party

Organisation name	Individual name	Electronic mail address	Role
European Petroleum Survey Group		EPSGadministrator@iogp.org	Publisher

Unique resource identifier

urn:ogc:def:crs:EPSG::3031

Version

6.18.3

Hierarchy level

Dataset

Statement

Methodology:

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?)

Data collection:

To generate the predicted subglacial flow paths, we used the Python package, pysheds release 0.3.5 (Bartos, 2020).

Data 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.

Metadata

File identifier

0df5d4e9-2fcd-4420-b403-24d76848a5a5 XML

Metadata language

English

Character set

UTF8

Hierarchy level

Dataset

Hierarchy level name

dataset

Date stamp

2024-05-31

Metadata standard name

ISO 19115 Geographic Information - Metadata

Metadata standard version

ISO 19115:2003(E)

Metadata author

Organisation name	Individual name	Electronic mail address	Role
NERC EDS UK Polar Data Centre		polardatacentre@bas.ac.uk	Point of contact