An iceberg the size of Rhode Island is on the move again after spending months trapped in a whirling ocean vortex.
The iceberg, named A23a, measured 1,505 square miles in area in February this year, making it the largest iceberg in the world.
As of December 13, the iceberg measured 1,062 square miles, according to the U.S. National Ice Center, but had reached sizes as large as 1,700 square miles last November.
A23a broke off from the Filchner-Ronne Ice Shelf near the Antarctic Peninsula in 1986 but became grounded in the Weddel Sea shortly afterward, where it would stay for over three decades.
In 2020, the iceberg broke free of the seafloor, likely as a result of melting below the water, and floated northwards along the eastern coast of the Antarctic Peninsula until summer 2024. At this point, A23a became trapped in a rotating current known as a Taylor Column north of the South Orkney Islands, spinning anticlockwise at a rate of about 15 degrees a day.
After months of being caught in this current, the iceberg has finally escaped and is now drifting into the Southern Ocean in the direction of South Georgia.
"It's exciting to see A23a on the move again after periods of being stuck. We are interested to see if it will take the same route the other large icebergs that have calved off Antarctica have taken. And more importantly what impact this will have on the local ecosystem," Andrew Meijers, an oceanographer at British Antarctic Survey and co-lead of the the OCEAN:ICE project, said in a statement.
While A23a is still the largest iceberg in the world and has been for much of the last 30 years with other icebergs sporadically claiming the title, such as A68 in 2017 and A76 in 2021.
The largest iceberg ever recorded is Iceberg B-15, which calved from Antarctica's Ross Ice Shelf in March 2000. This iceberg measured approximately 4,250 square miles -- nearly the size of Connecticut.
Sadly, A23a's long reign may soon come to an end, as it is expected to break up and melt away as it travels into warmer waters.
Researchers at the British Antarctic Survey watched the iceberg closely during its long journey, studying how A23a and others like it influence Antarctic ecosystems and the global cycle of nutrients in the oceans.
"We know that these giant icebergs can provide nutrients to the waters they pass through, creating thriving ecosystems in otherwise less productive areas. What we don't know is what difference particular icebergs, their scale, and their origins can make to that process," Laura Taylor, a biogeochemist at the British Antarctic Survey, said in the statement.
"We took samples of ocean surface waters behind, immediately adjacent to, and ahead of the iceberg's route. They should help us determine what life could form around A23a and how it impacts carbon in the ocean and its balance with the atmosphere."
Antarctica is losing ice faster than ever before. One 2018 study in the journal Nature found that Antarctica lost around 3 trillion metric tons of ice from 1992 to 2017, with the rate of loss increasing from about 76 billion metric tons per year before 2012 to 219 billion metric tons per year in most recent years.