– Scientists have discovered what causes a large ice hole the size of Switzerland to periodically form in Antarctica’s Weddell Sea, solving a decades-long mystery.
– Known as the Maud Rise polynya, the hole was first observed in the 1970s but would appear sporadically, leaving its cause unclear. It reopened at a massive size in 2016-2017, allowing intensive study.
– Researchers found that in recent reopenings, stronger winds from the Weddell Gyre ocean current brought warmer, saltier water up near the icy surface over the Maud Rise underwater mountain.
– This salter water lowered the freezing point, preventing ice from forming and keeping the polynya open. Its persistence impacted ocean circulation and heat transport.
– Future stronger Antarctic winds due to climate change may cause more frequent polynya formation, altering regional/global ocean currents and climates for years after. Understanding these holes provides insight into Antarctic/ocean dynamics.
Source: Live Science
