south georgia

The largest iceberg in the world, which has been slowly drifting for nearly 5 years, has finally come to a halt. The iceberg – called the unexciting name A-23A – came into existence in 1986 when it broke off from another iceberg A-23 that had calved or torn off from Antarctica earlier that year. For decades, A-23A sat in the Weddell Sea, east of the Antarctic Peninsula. Then, in 2020, it came loose from the seafloor and began to move. By 2023, it finally left Antarctic Waters.

Late last year, it began spinning in place caught in an ocean current called a Taylor column. Finally, it headed for South Georgia, a British-owned island that is home to a couple dozen people and lots of seals and penguins. A-23A is now stuck on the continental shelf, about 50 miles from the island.

A-23A is around 1,300 square miles in area. By comparison, New York City is 300 square miles.

Four years ago, a large iceberg called A-68A also came to ground in the vicinity of South Georgia. It quickly broke apart and ultimately added 150 billion metric tons of fresh water to the ocean as well as various nutrients. A-23A is also likely to succumb to the warmer waters, winds, and currents it now encounters and will affect the flora and fauna in the area.

The climate is changing and is impacting how ice shelves melt. Calving and the creation of mammoth icebergs are a normal part of the lifecycle of polar ice sheets, but we are likely to see even more events like this in the future.

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World’s Largest Iceberg Runs Aground

Photo, posted January 29, 2011, courtesy of Drew Avery via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

An international research team has revealed that critically endangered Antarctic blue whales have returned to the sub-Antarctic island of South Georgia, 50 years after whaling just about wiped them out. Other recent research has found that humpback whales are also returning to the region.

Blue whales were commonplace off South Georgia before 20th century industrial whaling taking place between 1904 and 1971 killed over 42,000 of them there. Most of that number were killed before the mid-1930s. As a result, blue whales essentially vanished from the region. Whale survey ships sighted only a single blue whale between 1998 and 2018.

But things have changed in recent years. A survey this past February resulted in 58 blue whale sightings and numerous acoustic detections. Although commercial whaling was banned in the area in the 1960s, it has taken a long time for the whales to make a comeback.

Researchers are not sure why blue whales have taken so long to return to the area. It may be that so many were killed over the years that the remaining population had little or no cultural memory of South Georgia Island as a foraging ground, and that it is only now being rediscovered.

In total, 41 individual blue whales have been photo-identified from South Georgia over the past 10 years, although none of those matched the 517 whales in the current Antarctic blue whale photographic catalogue. Dedicated whale surveys are difficult in a region known for its harsh weather and inaccessibility but are crucial to the future management of South Georgia’s seas. In any case, researchers see the recent sightings as a very positive step forward for conservation of the Antarctic blue whale.

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Blue whales return to South Georgia after near extinction

Photo, posted September 7, 2007, courtesy of the NOAA Office of National Marine Sanctuaries via Flickr. Photo credit: NOAA.

Earth Wise is a production of WAMC Northeast Public Radio.

The largest iceberg runs aground

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Return Of The Blue Whales | Earth Wise

An international research team has revealed that critically endangered Antarctic blue whales have returned to the sub-Antarctic island of South Georgia, 50 years after whaling just about wiped them out. Other recent research has found that humpback whales are also returning to the region.

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