Very high-resolution images were released of the crack that resulted in the emergence of Antarctica’s latest mega-iceberg.
The A74, as the 1,290 km2 (500 square miles) block is known, separated from Brunt’s ice shelf exactly a week ago.
The new photos from last Saturday show the enlargement of the “Fenda Norte” one day after delivery.
They were acquired by the British satellite Vision-1 for the British Antarctic Survey.
BAS has its Halley Research Station at Brunt, located about 23 km from the crack.
Also in the hands of BAS are new radar images captured on Thursday by the EU’s Sentinel-1 spacecraft. This gives a broader view of the 150m-thick A74 entering the Weddell Sea of Antarctica.
BAS is using all of these spatial images to monitor events. The Cambridge-based agency wants to see if the A74 can collide with the western part of the Brunt and start a second delivery even closer to Halley.
The base is currently unoccupied. In part, this is because of Covid; very little Antarctic science is being carried out at the moment. But it is also because BAS needs to make sure that the Brunt ice shelf – a vast floating ice shelf – will remain stable in the future.
Halley would be 17 km from the most likely location for a second delivery.
The GPS sensors around Halley did not report any reaction on the ice directly under the base in the days following the production of the A74. BAS is confident that the same would be true in a second split, but the agency would obviously like the certainty that comes with the data.
The Vision-1 satellite was built by Surrey Satellite Technology Ltd of Guildford. It is a subsidiary of the European aerospace giant Airbus.
Vision-1 can resolve details on the Earth’s surface less than a meter in diameter.
Where exactly is this?
It is on the Brunt ice shelf, which is the floating ledge of the glaciers that flowed from the land into the Weddell Sea. On a map, the Weddell Sea is that sector of Antarctica directly south of the Atlantic Ocean. The Brunt is on the east side of the sea. Like all ice rigs, it periodically creates icebergs.
How big is the new iceberg?
The satellite’s measurement places it at about 1,290 km2. Greater London is approximately 1,500 square kilometers; the Welsh county of Monmouthshire is about 1,300 square kilometers. This is big by any measure, although not as big as the A68 iceberg monster, which spawned in July 2017 on the Larsen C ice shelf on the west side of the Weddell Sea. This was originally about 5,800 square kilometers, but has since broken into many small pieces.
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