thumb|upright=1.35|Northern edge of Iceberg B-15A in the Ross Sea, Antarctica, 29 January 2001 Iceberg B 15 was the largest recorded iceberg by area. It measured around , with a surface area of , about the size of the island of Jamaica. Calved from the Ross Ice Shelf of Antarctica in March 2000, Iceberg B-15 broke up into smaller icebergs, the largest of which was named Iceberg B-15-A. In 2003, B-15A drifted away from Ross Island into the Ross Sea and headed north, eventually breaking up into several smaller icebergs in October 2005. In 2018, a large piece of the original iceberg was steadily moving northward, located between the Falkland Islands and South Georgia Island. , the U.S. National Ice Center (USNIC) still listed one extant piece of B-15 that meets the minimum threshold for tracking (). This iceberg, B-15AB, measured ; it was, as of 2021, grounded off the coast of Antarctica in the western sector of the Amery region.
History
thumb|upright=1.2|Iceberg B-15A four-year journey, July 2002 to March 2006
thumb|[[USCGC Polar Sea|USCGC Polar Sea nears Iceberg B-15A in January 2001]]
thumb|Iceberg B-15Z route 2014-2018
In the last weeks of March 2000, Iceberg B-15 calved from the Ross Ice Shelf near Roosevelt Island, Antarctica. The calving occurred along pre-existing cracks in the ice shelf.
In November 2003, after the separation from B-15J, B-15A drifted away from Ross Island on the open waters of the Ross Sea. In December 2003, a small knife-shaped iceberg, B-15K (about 300 km<sup>2</sup>), 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 extension of the land-based David Glacier, which flows through the coastal mountains of Victoria Land. A few kilometres from the ice tongue, the iceberg became stranded on a shallow seamount before resuming its northward course. On 10 April 2005, B-15A collided with the ice tongue, breaking off the tip of the ice tongue; the iceberg seemed unaffected by the collision. and broke into several smaller pieces, the largest of which was still named B-15A (now measuring approximately ). Three additional pieces were named B-15P, B-15M, and B-15N. Iceberg B-15A then moved farther up north and broke up into more pieces. These were spotted by air force fisheries patrol on 3 November 2006. On 21 November 2006 several large pieces were seen just off the coast of Timaru, New Zealand—the largest measured about , rising from the surface of the ocean.
As of 2018, four pieces remained that were large enough to be tracked by the National Ice Center (at least ).
By 2020, only two pieces remained large enough to track. B-15aa – a direct remnant of B-15z – was drifting to the east of the island of South Georgia, in the south Atlantic Ocean. B-15ab remained among sea ice along the coast of Antarctica south of Africa. 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 swell travelled from Alaska to Antarctica over six days. Scientists are studying this event as an example of how weather in one area can have effects in other parts of the world, and with concern over the effects on global warming.
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.