Giant iceberg nearly the size of Greater London breaks off Brunt Ice Shelf in Antarctica
A giant iceberg almost the size of Greater London broke off the Brunt Ice Shelf in Antarctica on Sunday (January 22) - but Cambridge scientists say it is not related to climate change.
The enormous 1,550 square kilometre calved because of the natural development of cracks over the last few years that have extended across the entire 150m thick ice shelf.
A crack known as Chasm-1 fully extended through the ice shelf, leading to the iceberg breaking free between 7pm and 8pm UTC, during a spring tide.
The break-off is the second major calving in the area in two years.
Scientists at the Madingley-based British Antarctic Survey first detected the growths of vast cracks in the ice a decade ago.
The BAS Halley Research Station is located on the Brunt Ice Shelf, but its glaciologists, who have been monitoring the situation, say the area it sits on is unaffected by the recent calving events.
However, the impact of calving events is unpredictable due to the complex glaciological structure of the ice shelf, so BAS took the precaution in 2016 of relocating Halley Research Station 23km inland of Chasm-1 after it began to widen.
Staff have been deployed to the station since 2017 only during the Antarctic summer, which runs from November to March.
There are currently 21 staff at the station maintaining the power supplies and facilities that keep the scientific experiments operating remotely through the winter. They will continue to work on site until an aircraft picks them up around February 6.
Prof Dame Jane Francis, director of BAS, says: “Our glaciologists and operations teams have been anticipating this event. Measurements of the ice shelf are carried out multiple times a day using an automated network of high-precision GPS instruments that surround the station.
“These measure how the ice shelf is deforming and moving, and are compared to satellite images from ESA, NASA and the German satellite TerraSAR-X. All data are sent back to Cambridge for analysis, so we know what is happening even in the Antarctic winter - when there are no staff on the station, it is dark for 24 hours and the temperature falls below minus 50 degrees C (or -58F).”
Prof Dominic Hodgson, BAS glaciologist, added: “This calving event has been expected and is part of the natural behaviour of the Brunt Ice Shelf. It is not linked to climate change.
“Our science and operational teams continue to monitor the ice shelf in real-time to ensure it is safe, and to maintain the delivery of the science we undertake at Halley”.
