On 26 February, an iceberg measuring approximately 1,270 square kilometres broke off the Brunt Ice Shelf in the south of the Weddell Sea.
Thanks to images provided by Argentina’s SAOCOM 1A satellite, specialists from the Argentine Antarctic Institute (IAA), which reports to the Foreign Ministry, were able to detect the calving of an iceberg in Antarctica and to determine that it measures approximately 1,270 square kilometres.
The Department of Glaciology of the IAA has been studying the stability and dynamics of ice shelfs in Antarctica for decades, especially in the Antarctic Peninsula. Access to satellite images provided by missions of different space agencies is essential to study and track the bodies of ice. Sensors are installed at places that are close enough to enable access during the summer Antarctic campaigns, and measurements are carried out in addition to the satellite data.
In recent years, Argentina has launched two satellites that were developed domestically, SAOCOM 1A and SAOCOM 1B, both of the National Commission for Space Activities (CONAE). “Development of national science and technology has given our country access to more images to expand the satellite database and to track more regularly the dynamics of Antarctic glaciers,” stated the Secretary for the Malvinas, Antarctica and South Atlantic, Daniel Filmus.
Process and tracking
An ice shelf is formed by a floating ice mass that is the extension in the ocean of glaciers coming from the continent, in this case from Antarctica. The ice flowing down from the mountains or from the Antarctic elevations keeps moving and provides ice to the shelves, pushing them to the open sea. Once the movement causes the internal forces to exceed the breakdown point, either because of the tides or because they hit a geographical accident, the ice breaks and a crack appears. This process is natural for glaciers and for ice shelves too. The cracks widen until an ice block breaks off and becomes detached. When this process takes place in the water, the block becomes an iceberg.
In the case of the Brunt Ice Shelf, this process, which started at the end of 2019, evolved during 2020 creating an iceberg of approximately 1,270 square kilometres. The magnitude of the ice shelves and the distance from the Antarctic stations can be significant. The Argentine Belgrano II Station, for example, is located 400 kilometres southeast from the shelf. The cities that house the research institutions that carry out the tracking and study of these bodies of ice are much further away. Therefore, they are tracked mainly through satellite images.
This shelf, which has lost 1,270 square kilometres, has other vast cracks that appeared in recent years and that will cause other calving events in the future. That is the reason why the tracking will continue after this calving event. As long as the shelf does not suffer the activity of the oceans and stays in low-temperature sea areas it can remain without melting for many years. However, it is important to study these iceberg detachments in order to acquire more knowledge about the dynamics of Antarctic ice shelves.
As far as navigation is concerned, only a few ships sail in this remote austral area. The Argentine logistics and scientific campaign accessed this area at the end of last January and will not do so again until next summer, so the next step is to continue tracking the position of the iceberg (and any other icebergs that may detach) to plan and support the sailing of the next Summer Antarctic Campaign. In addition to our logistics ships, any ship sailing in Antarctic waters that requests information from the Argentine satellites will benefit from these images, using them as a tool for navigation assistance, which reflects the multiple uses of these type of data.
