98a92a0c-4fa3-4319-a554-f85d1564de40 eng utf8 dataset dataset NERC EDS UK Polar Data Centre +44 (0)1223 221400 British Antarctic Survey, High Cross, Madingley Road Cambridge Cambridgeshire CB3 0ET United Kingdom polardatacentre@bas.ac.uk https://www.bas.ac.uk/team/business-teams/information-services/uk-polar-data-centre/ information pointOfContact 2025-04-24 ISO 19115 Geographic Information - Metadata ISO 19115:2003(E) European Petroleum Survey Group (EPSG) Geodetic Parameter Registry 2008-11-12 publication European Petroleum Survey Group EPSGadministrator@iogp.org https://www.epsg-registry.org/ EPSG Geodetic Parameter Dataset The EPSG Geodetic Parameter Dataset is a structured dataset of Coordinate Reference Systems and Coordinate Transformations, accessible through this online registry. information publisher urn:ogc:def:crs:EPSG::3031 6.18.3 Topographic data for Alexander Island and the surrounding region, including coastline, grounding line, contours, spot heights, rock outcrop and lakes (2022 - 2025) 2025-04-24 creation 2025-04-24 revision 2025-04-24 publication 2025-04-24 released 1.0 https://doi.org/10.5285/98a92a0c-4fa3-4319-a554-f85d1564de40 doi GB/NERC/BAS/PDC/02049 https://data.bas.ac.uk/ Please cite this item as: Gerrish, L., Skachkova, A., Ireland, L., & Field, E. (2025). Topographic data for Alexander Island and the surrounding region, including coastline, grounding line, contours, spot heights, rock outcrop and lakes (2022 - 2025) (Version 1.0) [Data set]. NERC EDS UK Polar Data Centre. https://doi.org/10.5285/98a92a0c-4fa3-4319-a554-f85d1564de40 This record consists of 5 different datasets covering the Alexander Island region of Antarctica: coastline (including grounding line and ice shelf fronts), contours, spot heights, rock outcrop and lakes. The data have been produced for a new topographic map of Alexander Island at 1:500,000 scale, produced by the Mapping and Geographic Information Centre, British Antarctic Survey. The data are suitable for a 1:500,000 scale map but may be suitable for larger scales in certain areas. They have been created from source data ranging from 2022 - 2025. The data primarily cover Alexander Island, and also cover Rothschild, Charcot and Latady islands, as well as Wilkins and George VI ice shelves, and the Rymill Coast section of Palmer Land on the Antarctic Peninsula. The datasets were created using a mixture of GIS software, primarily digitised from Sentinel-2 satellite imagery or extracted from high resolution, published elevation models. Exact details of each dataset can be found in the lineage statements. No credit. completed Gerrish, Laura British Antarctic Survey Researcher author Skachkova, Aliaksandra British Antarctic Survey Researcher author Ireland, Louise British Antarctic Survey Researcher author Field, Elena British Antarctic Survey Researcher author NERC EDS UK Polar Data Centre +44 (0)1223 221400 British Antarctic Survey, High Cross, Madingley Road Cambridge Cambridgeshire CB3 0ET United Kingdom PDCServiceDesk@bas.ac.uk https://www.bas.ac.uk/team/business-teams/information-services/uk-polar-data-centre/ information pointOfContact asNeeded completed EARTH SCIENCE > Land Surface > Topography > Contours EARTH SCIENCE > Land Surface > Topography > Terrain Elevation EARTH SCIENCE > Land Surface > Topography theme Global Change Master Directory (GCMD) Science Keywords 2026-01-27 publication 23 Global Change Data Center, Science and Exploration Directorate, Goddard Space Flight Center (GSFC) National Aeronautics and Space Administration (NASA) Greenbelt MD United States of America https://earthdata.nasa.gov/about/gcmd/global-change-master-directory-gcmd-keywords Global Change Master Directory (GCMD) Keywords The information provided on this page seeks to define how the GCMD Keywords are structured, used and accessed. It also provides information on how users can participate in the further development of the keywords. information publisher Alexander Island cartography coastline contours elevation grounding line lakes rock outcrop spot heights topographic theme Alexander Island Antarctica Wilkins Ice Shelf Antarctica George VI Ice Shelf Antarctica Fossil Bluff Antarctica Latady Island Antarctica Rothschild Island Antarctica Charcot Island Antarctica Rymill Coast Antarctica Bach Ice Shelf Antarctica place Land cover theme GEMET - INSPIRE themes, version 1.0 2021-01-06 revision otherRestrictions no limitations to public access otherRestrictions no limitations license Open Government Licence v3.0 otherRestrictions Data supplied under Open Government Licence v3.0 otherRestrictions None url url crossReference doi doi crossReference doi doi crossReference doi doi crossReference doi doi crossReference url url largerWorkCitation url url crossReference url url crossReference url url crossReference url url crossReference textTable eng utf8 elevation environment geoscientificInformation -77.47722 -67.4997 -72.61944 -68.6888 2022-01-01 2025-04-20 200.0 2800.0 urn:ogc:def:crs:EPSG::5714 MSL height Not specific to any location or epoch. Hydrography. 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. NERC EDS UK Polar Data Centre +44 (0)1223 221400 British Antarctic Survey, High Cross, Madingley Road Cambridge Cambridgeshire CB3 0ET United Kingdom PDCServiceDesk@bas.ac.uk https://www.bas.ac.uk/team/business-teams/information-services/uk-polar-data-centre/ information distributor application/zip application/vnd.shp bytes 10171187 http://ramadda.data.bas.ac.uk/repository/entry/show?entryid=98a92a0c-4fa3-4319-a554-f85d1564de40 WWW:LINK-1.0-http--link Get Data Download data download bytes 10171187 http://ramadda.data.bas.ac.uk/repository/entry/show?entryid=98a92a0c-4fa3-4319-a554-f85d1564de40 WWW:LINK-1.0-http--link Get Data Download data download dataset Methodology: Coastline: The starting point for this data was version 7.8 of the Antarctic Digital Database coastline (doi.org/10.5285/98d7c98c-b223-4774-b20e-886630632b12). Using ArcGIS Pro version 3.3.0, the data was clipped to this area of interest and every section of line was checked against current satellite imagery, and updated where necessary. The grounding line has undergone a major revision, with the majority of new data being incorporated from Wallis et al, 2024, https://doi.org/10.5194/tc-18-4723-2024 . There ar 5 fields in the attribute table of the final dataset: * 'surface' - detailing whether the line is 'ice coastline', 'rock coastline', 'ice shelf and front' or 'grounding line' * 'revdate' - revision date * 'source' - the source of each section of line, mostly consisting of satellite name and ID * 'sourcedate' - the date of the source, mostly in YYYY-MM-DD format apart from 2 sources where a year is only available * 'lineage' - a brief description of how each section of line was created The coordinate reference system of the data is WGS84 Antarctic Polar Stereographic, EPSG 3031. Contours: Using ArcGIS Pro version 3.3.0, contours were extracted from two different Digital Elevation Models and then merged together into 1 file. The majority of contours were created from REMA v2 (Howat, Ian, et al., 2022, ''The Reference Elevation Model of Antarctica - Mosaics, Version 2'', https://doi.org/10.7910/DVN/EBW8UC, Harvard Dataverse, V1, accessed September 2024.) apart from Latady Island and Charcot Islands which were created from the Copernicus GLO-90 DEM (https://doi.org/10.5270/ESA-c5d3d65). For REMA, the 500m mosaic was downloaded and converted to EGM2008 geoid, and contours were extracted. For the Copernicus GLO-90 DEM, the 90m tiles were used and contours were extracted from these, and then smoothed using a 60m smoothing tolerance. The two areas were merged together, and there is a field in the attribute table called 'source' which details which source each line comes from. The main field is called 'Contour' and contains the height in metres of each contour line. There are also fields for 'surface' which states whether the contour falls on ice or ice-free ground, and a field called 'interval' which states 'yes' or 'no' depending on whether the contour is an interval of 1000 or not. These fields are to improve cartographic presentation of the data, when styled using the fields. The coordinate reference system of the data is WGS84 Antarctic Polar Stereographic, EPSG 3031. Spot heights: This file contains 905 spot heights for the Alexander Island region, each point identified as a local high point with the height extracted from the 2 metre mosaic tiles of REMA v2 (Howat, Ian, et al., 2022, ''The Reference Elevation Model of Antarctica - Mosaics, Version 2'', https://doi.org/10.7910/DVN/EBW8UC, Harvard Dataverse, V1, accessed September 2024.) Detailed methodology is given below. All processing was carried out in ArcGIS Pro version 3.3.0, apart from step 2 which was carried out in QGIS version 3.34.7. Only a selection of these heights are shown on the published Alexander Island map, but all of the points that were produced are published here. 1. 32 metre version tiles of REMA v2 were downloaded, merged together, and converted to use Mean Sea Level / EGM2008 heights. The 32 m version was used to start with because the 2 m version was too power and time intensive for processing. 2. Using the 'Spot Height Extractor' Plugin in QGIS (version 1.1 - https://plugins.qgis.org/plugins/Spot-Height-Extractor-Plugin-main/ ), spot heights were extracted from the 32 m mosaic. This plugin identifies local high points. A neighbourhood size of 101 was used, which gave an optimal number of output points. 3. Manual tidying of the output file was performed to delete points on ice shelves, and in other locations ...(72) Data collection: ArcGIS Pro (version 3.3.0) QGIS (version 3.34.7) QGIS Spot Height Extractor plugin version 1.1 Data quality: All data is subject to error and known potential errors have been detailed in the lineage statements. Elevation data accuracy statements can be seen in the source data publications. The coastline, rock and lakes have been interpreted from satellite imagery using the dataset creator's best knowledge of the region and available data. asNeeded completed