Guess what’s big, white, and weighs about one trillion metric tons? It’s iceberg A23a, and it’s finally moving away from the Antarctic Peninsula! This massive chunk of ice broke free from the ocean floor in November 2023 after being stuck there for 37 years.
Back in 1986, the Filchner Ice Sheet in West Antarctica gave birth to iceberg A23a. However, it got stuck in the Weddell Sea soon after. Thanks to a mix of winds and currents, the iceberg finally broke free in November last year.
For the past few weeks, A23a has been drifting aimlessly in the Weddell Sea, but recent satellite images reveal that it’s now heading north, away from the Antarctic Peninsula. The European Space Agency noted that it passed by Elephant Island and is on its way to the southern Atlantic Ocean. A video compiled from sea-ice concentration data shows A23a’s journey from November 1, 2023, to January 23, 2024.
Iceberg A23a is massive, covering an area of 1,544 square miles (4,000 square kilometers) and reaching a thickness of about 919 feet (280 meters). To put it in perspective, it’s so big that you could fit 68 Manhattan islands within its vast expanse. Andrew Meijers, the chief scientist on the RRS Sir David Attenborough polar research vessel, visited the iceberg earlier this month and described it as stretching as far as the eye can see.
Predicting the iceberg’s exact path is tricky, but based on the routes of similar icebergs like A68 and A76a, it’s likely to head towards the Antarctic Circumpolar Current. From there, it’s expected to move into the South Atlantic, an area often known as “iceberg alley.” As A23a enters warmer waters, it will gradually break down and disintegrate over several years. This natural process is beneficial for the marine life in its vicinity.
Giant icebergs like A23a can provide nutrients to the waters they pass through, fostering thriving ecosystems in less productive areas. Laura Taylor, a biogeochemist from the BIOPOLE project, mentioned that while we know these icebergs play a role in this process, we’re still learning about the specific impacts of their size and origins. The BIOPOLE mission, utilizing the RRS Sir David Attenborough, is currently studying A23a, having visited it before it broke free from the Weddell Sea.
In an interesting historical note, the Soviet Union’s Druzhnaya 1 Antarctic base was located on the Filchner ice sheet, where scientists worked from 1975 to 1986. When iceberg A23a broke loose in 1986, the base was still on top of it. In February 1987, the Soviets made one last visit, approaching the iceberg by ship to collect their equipment from the abandoned base.
For such great articles, stay connected with us on BEID News!