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Ocean currents break up a tabular iceberg.

ABSTRACT: In December 2020, giant tabular iceberg A68a (surface area 3900 km²) broke up in open ocean much deeper than its keel, indicating that the breakage was not immediately caused by collision with the seafloor. Giant icebergs with lengths exceeding 18.5 km account for most of the calved ice mass from the Antarctic Ice Sheet. Upon calving, they drift away and transport freshwater into the Southern Ocean, modifying ocean circulation, disrupting sea ice and the marine biosphere, and potentially triggering changes in climate. Here, we demonstrate that the A68a breakup event may have been triggered by ocean-current shear, a new breakup mechanism not previously reported. We also introduce methods to represent giant icebergs within climate models that currently do not have any representation of them. These methods open opportunities to explore the interactions between icebergs and other components of the climate system and will improve the fidelity of global climate simulations.

SUBMITTER: Huth A

PROVIDER: S-EPMC9581483 | biostudies-literature | 2022 Oct

REPOSITORIES: biostudies-literature

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Ocean currents break up a tabular iceberg.

Huth Alex A Adcroft Alistair A Sergienko Olga O Khan Nuzhat N

Science advances 20221019 42

In December 2020, giant tabular iceberg A68a (surface area 3900 km<sup>2</sup>) broke up in open ocean much deeper than its keel, indicating that the breakage was not immediately caused by collision with the seafloor. Giant icebergs with lengths exceeding 18.5 km account for most of the calved ice mass from the Antarctic Ice Sheet. Upon calving, they drift away and transport freshwater into the Southern Ocean, modifying ocean circulation, disrupting sea ice and the marine biosphere, and potentia ...[more]

PMID: 36260681

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