My Climate Change News

The mission to determine the impact of the giant A-68a iceberg on the important marine ecosystem of sub-Antarctic South Georgia is a success according to a team of researchers and engineers, from British Antarctic Survey (BAS) and National Oceanography Centre (NOC). This week (Monday 19 April) the U.S National Ice Center declared 'the end' of the A68 iceberg, because its fragments are now too small to track. This coincides with the return of the mission ship to Southampton in the UK last week (13 April). The team are piloting two submersible robotic gliders deployed in mid-February from the NOC-operated research ship RRS James Cook. The gliders named 'Doombar - 405' and 'HSB - 439', were launched into the water some 200kms offshore from South Georgia. Their mission was to monitor the effects of the melting of the 'mega-berg' on the ecosystem.

Dr. Alexander Brearley, an oceanographer at BAS, who is co-leading piloting of the gliders, says: "The experiment has provided us with a unique opportunity to understand the impact of a melting and fragmenting iceberg on the both physical properties and ecosystem of the Southern Ocean around South Georgia. Our highly-equipped autonomous vehicles have allowed us to take measurements closer to the icebergs than our research ship could safely manage, giving us new insights into how iceberg meltwater and the mineral dust it carries affects both ocean circulation and productivity of the ecosystem."

The mission was a high risk as gliders are not usually deployed so near icebergs. After a few days, 405 was overtaken by an iceberg and spent two weeks stuck under the ice. However, it extracted itself and was piloted to look at the downstream effects of the iceberg on the most biologically productive regions north of the island. Unfortunately, the team lost connection with the second glider 439, in late February, but are cautiously optimistic that it may re-appear.

BAS oceanographer Dr. Povl Abrahamsen, was the...