DOI: 10.5285/52c304a5-6ab5-4368-9152-4aad1efd9719
title: Contours, spot heights and lakes data for the Adelaide Island and Arrowsmith Peninsula region of Antarctica (2022-2025)

description: This record consists of 3 different datasets covering the Adelaide Island and Arrowsmith Peninsula region of Antarctica: contours, spot heights, and lakes. The data have been produced for an updated version of the 'Adelaide Island and Arrowsmith Peninsula' 1:250,000 scale map, produced by the Mapping and Geographic Information Centre, British Antarctic Survey. 
The data are suitable for a 1:250,000 scale map but may be suitable for larger scales in certain areas. They have been created from source data ranging from 2022 - 2025. 
The datasets were created using a mixture of GIS software, primarily extracted from high resolution published elevation models, and digitised from Sentinel-2 satellite imagery. Exact details of each dataset can be found in the lineage statement. The data is useful for cartographers as well as scientists interested in the mapping of this region. The data is used on the map alongside further data published in v7.11 of the Antarctic Digital Database, November 2025 (coastline:https://doi.org/10.5285/cc0b73c0-3b53-40fb-ae84-b5dce4ac163a and rock outcrop: https://doi.org/10.5285/815525ca-cefe-4fbf-9224-3ee784e7de4e).
description: Contours:
Using ArcGIS Pro v3.5.2, contours were extracted at 250 metre intervals from a Digital Elevation Model (DEM) created from two published datasets. The DEM is primarily created from the 32m mosaic version 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 June 2025) with some holes and artefacts filled with the Copernicus GLO-30 DEM (https://doi.org/10.5270/ESA-c5d3d65).
Once the contours were extracted, the lines were smoothed using a 500 m smoothing tolerance and all lines &lt;0.4 km in length were deleted. Finally, the lines were split dependant on whether they fall on ice or rock ground. These changes were to enhance cartographic presentation of the data when styled on the 1:250 000 scale map. 
The shapefile contains 3 fields: the main field is called 'contour' and contains the height in metres of each contour line. The heights are in respect of the EGM2008 geoid. There is also a field called 'rock_ice' which states whether the contour falls on ice or rocky ground, and a field called 'interval' which states 'yes' or 'no' depending on whether the contour is an interval of 1000 or not. The coordinate reference system of the data is WGS84 Antarctic Polar Stereographic, EPSG 3031.
Spot heights:
This file contains 355 spot heights for the Adelaide 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 June 2025.) 
The spot heights were primarily extracted using the 'Spot Height Extractor' Plugin in QGIS (version 1.1 - https://plugins.qgis.org/plugins/Spot-Height-Extractor-Plugin-main/ ), with extra heights extracted as deemed necessary to suit this region and scale of map. The 32 metre version tiles of REMA v2 were first used to identify the local high points, and the 2 metre tiles were then used to extract the exact high points.
Two files are available alongside the main REMA v2 elevation files, each indicating the accuracy of a local area: 'count' details the number of contributing DEMs, and 'mad' details the median absolute deviation of height values within the contributing DEMs. Details here: https://www.pgc.umn.edu/guides/stereo-derived-elevation-models/pgc-dem-products-arcticdem-rema-and-earthdem/ These figures are useful for assessing the confidence of individual heights that were extracted, with a lower mad value indicating potentially higher accuracy. Therefore the necessary mad and count .tif files were downloaded, and the values for each height were extracted.
Finally, a field for place name was added to the resultant shapefile, where the spot height appeared to be associated with a known place name in the British Antarctic Territory gazetteer, accessed September 2025 (https://apc.antarctica.ac.uk/ ). Where a height was not clearly identified with a place name, the field was left empty.
The final dataset contains the following attributes:
* 'msl_egm08' - the height of each point above mean sea level, calculated in respect of EGM08 geoid.
* 'hae_wgs84' - the height of each point above ellipsoid, calculated in respect of WGS84 ellipsoid.
* 'qa_count' - the 'number of contributing DEMs' to the REMA v2 tiles
* 'qa_mad' - the 'median absolute deviation of contributing DEMs' to the REMA v2 tiles
* 'name' - the associated place name for each point, if a name is present
The coordinate reference system of the data is WGS84 Antarctic Polar Stereographic, EPSG 3031.
Lakes:
The lakes in this dataset have been digitised from Sentinel-2 satellite imagery (Copernicus Sentinel data, 2025) in ArcGIS Pro version 3.5.2. The file contains 20 lakes, and four of them are officially named. The lakes are small and occasionally difficult to distinguish precisely in the imagery, but they have been digitised to the best of the dataset creator's knowledge. Furthermore, there might be further lakes that were not identified in this dataset, especially very small lakes.
The shapefile contains two fields: 'Source' contains the ID of the Sentinel-2 image that the lake has been digitised from, and 'Name' which contains the name of the lakes, from the British Antarctic Territory gazetteer, accessed November 2025. The coordinate reference system of the data is WGS84 Antarctic Polar Stereographic, EPSG 3031.
description: ArcGIS Pro (version 3.5.2)
QGIS (version 3.34.7)
QGIS Spot Height Extractor plugin version 1.1
description: 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 lakes have been interpreted from satellite imagery using the dataset creator's best knowledge of the region and available data.