Iceberg B-15

As of August 2023, the U.S. National Ice Center (USNIC) still lists one extant piece of B-15 that meets the minimum threshold for tracking (70 km2 or 20 sq nmi).

Scientists believe that the enormous piece of ice broke away as part of a long-term natural cycle, which occurs every fifty to one hundred years.

In December 2003, a small knife-shaped iceberg, B-15K (about 300 km2), detached itself from the main body of B-15A and started drifting northward.

By January 2005, prevailing currents caused B-15A to drift toward the Drygalski Ice Tongue, a 70-kilometre-long (40 nmi) extension of the land-based David Glacier, which flows through the coastal mountains of Victoria Land.

On 27–28 October 2005, the iceberg ran aground off Cape Adare in Victoria Land, generating seismic signals that were detected as far away as the Amundsen-Scott South Pole Station[10][11] and broke into several smaller pieces, the largest of which was still named B-15A (now measuring approximately 1,700 km2 or 500 sq nmi).

[13] In 2021, B-15ab became the last fragment to remain on the US National Ice Center list of tracked icebergs, still grounded off the coast of Antarctica.

The data gathered led to an unprecedented understanding of how giant icebergs make their way through the waters of Antarctica and beyond.

B-15A prevented ocean currents and winds from assisting in the 2004–2005 summer break-up of the sea ice in McMurdo Sound, and was an obstacle to the annual resupply ships to three research stations.

[14] A more detailed study in 2010, however, shows that the iceberg breakup was principally caused by repeated grounding with near-coastal bathymetry near Cape Adare, Victoria Land.