Date (Creation)

2020-09-08

Date (Revision)

2020-09-08

Date (Publication)

2020-09-08

Date (released)

2020-09-08

Edition

1.0

Unique resource identifier

https://doi.org/10.5285/649bbe03-8109-45be-92e5-bcef44a4703a

Codespace

doi

Unique resource identifier

GB/NERC/BAS/PDC/01376

Codespace

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

Unique resource identifier

NE/L002590/1

Codespace

award

Unique resource identifier

NE/R000824/1

Codespace

award

Other citation details

Please cite this item as: Arthur, J., Stokes, C., Jamieson, S., Carr, J., & Leeson, A. (2020). Observations of supraglacial lakes on Shackleton Ice Shelf, East Antarctica from 1974 to 2020 (Version 1.0) [Data set]. UK Polar Data Centre, Natural Environment Research Council, UK Research & Innovation. https://doi.org/10.5285/649bbe03-8109-45be-92e5-bcef44a4703a

Credit

No credit.

Status

Completed

Point of contact

Organisation name	Individual name	Electronic mail address	Role
Durham University	Arthur, Jennifer		Author
Durham University	Stokes, Chris		Author
Durham University	Jamieson, Stewart		Author
Newcastle University	Carr, J		Author
Lancaster University	Leeson, Amber		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 > Cryosphere > Glaciers/Ice Sheets > Glacier Topography/Ice Sheet Topography
• EARTH SCIENCE > Cryosphere > Glaciers/Ice Sheets > Glaciers
• EARTH SCIENCE > Hydrosphere > Glaciers/Ice Sheets > Glacier Topography/Ice Sheet Topography
• EARTH SCIENCE > Hydrosphere > Glaciers/Ice Sheets > Glaciers
• EARTH SCIENCE > Cryosphere > Glaciers/Ice Sheets
• EARTH SCIENCE > Hydrosphere > Glaciers/Ice Sheets
• EARTH SCIENCE > Spectral/Engineering > Visible Wavelengths

Theme

• Antarctica

• glaciology

• hydrology

• ice sheets

• supraglacial lakes

Place

• Shackleton Ice Shelf Antarctica

GEMET - INSPIRE themes, version 1.0

• Elevation
• Hydrography

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

This data is supplied under Open Government Licence v3.0

Unique resource identifier

url

Codespace

url

Association Type

Cross reference

Unique resource identifier

doi

Codespace

doi

Association Type

Cross reference

Spatial representation type

Text, table

Language

English

Character set

UTF8

Topic category

• Geoscientific information
• Imagery base maps earth cover
• Inland waters

Begin date

1974-02-23

End date

2020-02-28

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 the Normalised Difference Water Index adapted for ice (NDWI; Yang and Smith 2013) to classify pixels as 'water' or 'non-water' (i.e. ice, snow, exposed bedrock or ocean) using the red and blue bands. All processing was conducted in Arcmap 10.5.

We applied a physically-based radiative transfer model to calculate the water depth of all pixels classified as lake (Pope et al., 2016; Sneed and Hamilton 2007). This method calculates lake water depth (z) using the rate of light attenuation in water, lake bottom albedo, and optically-deep water reflectance (Philpot, 1989).

A detailed description of the data collection, quality control, processing and analysis is given in: Arthur, J.F, Stokes, C.R., Jamieson, S.S.R, Carr, J.R, Leeson, A.A (2020) Distribution and seasonal evolution of supraglacial lakes on Shackleton Ice Shelf, East Antarctica. doi: 10.5194/tc-2020-101.

Data quality:

We used a minimum size threshold of two pixels, in order to remove very small SGLs likely comprised solely of mixed pixels (i.e. 200 m2 for Sentinel 2, 450 m2 for Landsat 7/8, 1800 m2 for Landsat 4/5, 7200 m2 for Landsat 1), following previous studies (Moussavi et al., 2020; Pope et al., 2016, Stokes et al., 2019).

We quantified the uncertainties in our mapping technique by quantitatively comparing SGL areas derived from NDWI with those derived from manual digitisation in four sample areas. The smaller SGLs (<0.01 km2) generated the largest percentage differences, and we found a mean absolute error of 0.007 and a root mean square error of 0.029 between manually-digitised SGL areas and those derived from NDWI. We attribute this to manual digitisation being less conservative at 'diffuse', less well-defined SGL edges. Despite these differences, we found very close agreement between the two methods (R2 = 0.979, p = 0.006). We also quantified the impact of sensor resolution on lake detection and lake extents, and found there is generally a very good agreement between lake areas derived from Landsat 8 and Sentinel 2 (Supplementary Fig. 3). We therefore assign a conservative uncertainty of 1% to our total SGL area for each time step, following Stokes et al. (2019).

We checked final lake masks against RGB composites and manually removed any false positives, including small bedrock outcrops not included in the bedrock mask and dark crevasses. To further reduce noise and improve the visual clarity of the dataset, we then applied the dissolve function in ArcMap to clean up overlapping pixels and the aggregate tool to combine pixels within a distance of two pixels.

A detailed description of the data collection, quality control, processing and analysis, as well as full references, is given in:

Arthur, J.F, Stokes, C.R., Jamieson, S.S.R, Carr, J.R, Leeson, A.A (2020) Distribution and seasonal evolution of supraglacial lakes on Shackleton Ice Shelf, East Antarctica. doi: 10.5194/tc-2020-101.

Metadata

File identifier

649bbe03-8109-45be-92e5-bcef44a4703a XML

Metadata language

English

Character set

UTF8

Hierarchy level

Dataset

Hierarchy level name

dataset

Date stamp

2020-09-08

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