The important changes caused by the melting ice and, to a lesser extent, the construction of infrastructures (ports, cities, roads) are key elements in the new maps of the polar regions produced by the British Antarctic Survey (BAS), a public scientific institution in the United Kingdom. United Kingdom specializing in polar studies.
BAS polar maps have become a world reference in recent years and are widely used in scientific studies and maritime navigation. The update of these maps, presented this Thursday, June 8, reveals the alterations in the coastline, islands and ice masses associated with climate change (thaw, rise in sea level).
The new edition of maps contains "completely new data on the extent of sea ice, updated cities and airports in the Arctic, and new contours of the ice shelf in Antarctica after the recent calving of giant icebergs," explain those responsible for this. I work at BAS.
The Arctic map covers all land and ocean north of 60°N and this particular map has been completely updated, with every piece of information updated or verified.
Many cities in the Canadian Arctic are now known by their indigenous names and now appear on the map. These include Sanirajak and Naujaat. In all areas of the Arctic, man-made features such as roads, railways and airports are continually changing due to improved links to more remote areas.
Notable physical changes in the update include new ice fronts that reflect the retreat of many large glaciers flowing from Greenland and Svalbard, and changes in the extent of lakes as the landscapes around them adapt.
The maps are complemented by four inset maps showing current and relevant issues for the region. The Arctic maps show permafrost and land cover, which are important and rapidly changing aspects of the Arctic landscape, and both sides have maps showing the extent of sea ice.
The BAS details that the maps show the 30-year average extent of sea ice, although these extents change year by year, especially in the Arctic. Therefore, a new recent 10-year average has been produced to compare it to the 30-year average.
The difference in the length of summer in the Arctic is marked, recalls the BAS. Climate models that best show the observed evolution of Arctic sea ice suggest that the Arctic Ocean will be essentially free of sea ice, in the summer, before 2050. There is considerable uncertainty in the exact date due to natural variations in climate, and some models suggest it. "It is likely to occur, at least once, in the 2030s," says the BAS.
Other updates include new extensions to the ice shelf in Antarctica. For example, with the calving of the giant iceberg A76 from the Ronne Ice Shelf in 2021 and the very recent calving of iceberg A81 in 2023 from the Brunt Ice Shelf, where BAS Halley Research Station is located, many shelf fronts ice sheets are now closer to the continent. than they were in previous versions of the maps. The reduced extent of the ice shelves must be shown to accurately represent the new landscape.
BAS cartographer Elena Field, one of the authors of the new mapping, explains that “the polar regions are changing rapidly, both due to the effects of climate change and improved infrastructure and transport routes, so we must update these maps frequently to stay current. In addition, the best data on geography from satellite imagery gives us a bird's-eye view of the continent, which is now better mapped than ever before."
Other enhancements include updates to the contours and shading of background hills in the terrain as well as bathymetry. Hill contours and shading are derived from the recently published REMAv2 dataset from the Polar Geospatial Center which covers Antarctica in detail never before known for the entire continent. And the bathymetry is from a new version of the "General Bathymetric Chart of the Ocean" that BAS scientists and data managers have been a part of by entering data collected on various science ship cruises.
Maps of the Antarctic region also show changes in contours, surfaces, and floating ice masses. One of the details highlighted by the BAS shows the extent of sea ice for the Ronne and Brunt ice shelves (British Antarctic Survey).
