A groundbreaking discovery has shed light on the mysterious reappearance of a massive ice hole in Antarctica, equivalent in size to Switzerland.
The unique ice-free water void, known as a polynya, was initially observed by scientists in 1974 and remained open for two years before closing up.
However, in 2016 and 2017, researchers were puzzled by the sudden reappearance of the large polynya, prompting them to investigate the underlying cause.
The Unveiled Explanation
Researchers from the University of Southampton uncovered that a combination of ocean winds, water currents, and increased salt levels in the water were melting the sea ice and creating the colossal hole.
The polynya was named Maud Rise by scientists in the 1970s, derived from the underwater mountain located beneath it in the Weddell Sea.
While polynyas typically form annually in Antarctic coastal sea ice, the occurrence of one hundreds of miles away in the open ocean is uncommon.
Lead author of the study and postdoctoral research fellow at the University of Southampton, Aditya Narayanan, explained, "The Maud Rise polynya was discovered in the 1970s when remote sensing satellites that can see sea ice over the Southern Ocean were first launched. It persisted through consecutive winters from 1974 to 1976, and oceanographers back then assumed it would be an annual occurrence."He continued, "But since the 1970s, it has occurred only sporadically and for brief intervals.2017 was the first time that we've had such a large and long-lived polynya in the Weddell Sea since the 1970s."
Impact on Oceans
Researchers have cautioned that polynyas can have adverse effects on oceans, potentially leading to a rise in sea levels, which saw a 0.3-inch increase from 2022 to 2023.
The study's co-author, Professor Sarah Gille from the University of California, stated, "The imprint of polynyas can remain in the water for multiple years after they've formed. They can change how water moves around and how currents carry heat towards the continent. The dense waters that form here can spread across the global ocean.
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(With inputs from agencies)
English (US)