The huge iceberg A68a has dumped 1 billion tons of fresh water into the ocean

When its main body broke off Antarctica, which grew to be three times the size of London or more than twice the size of Luxembourg and reached shallow waters off the subantarctic island of South Georgia, it poured 5.3 cubic kilometers of water fresh to salty ocean water , as shown by the European Space Agency’s satellite analyzes of the melting of this colossal iceberg.

Iceberg A68a’s journey began in July 2017 when it broke off the Larsen-C Ice Shelf. Its journey, as it moved north from the Antarctic Peninsula, was mapped using five different satellites: Sentinel-1, Sentinel-3, MODIS, CryoSat-2, and ICESat-2. With them, the researchers from the Center for Polar Observation and Modeling (CPOM) and the British Antarctic Survey (BAS) the change in area of the iceberg while it melted and the modification of its thickness, which led to determining the area, thickness and the change in volume of the iceberg and calculate when it had lost its structure, where it had melted and the likely impact of that melting.

“Frequent measurements allowed us to follow every movement and rupture of the iceberg as it inched north through the iceberg alley and out into the Scotia Sea, where it then picked up speed and came very close to South Georgia Island.” , explains Laura Gerrish, a specialist in GIS and mapping at BAS and co-author of the study published in the journal Remote Sensing of Environment.

a massive spill

What effect can such an amount of fresh water deposited have on the salty waters of the ocean? According to scientists, it could have a profound effect on marine life in South Georgia, a wildlife sanctuary in the Southern Ocean. Scour marks from the ice slab can destroy wildlife, and the iceberg itself can block ocean currents and predator foraging routes.

When it first broke off the great slab of ice, it was the largest iceberg on Earth and the sixth largest ever recorded.

Referencia: A. Braakmann-Folgmann, A. Shepherd, L. Gerrish, J. Izzard, A. Ridout,

Observing the disintegration of the A68A iceberg from space,

Remote Sensing of Environment,

Volume 270, 2022, 112855, ISSN 0034-4257,

https://doi.org/10.1016/j.rse.2021.112855.

(https://www.sciencedirect.com/science/article/pii/S0034425721005757)