Scientists Found a Massive Hole In Antarctica in 2016 And Now, They've Finally Discovered What Caused It

During the winters of 2016 and 2017, Antarctica's onlookers were delivered a huge surprise. A massive gap in the Weddell Sea, a region of the continent typically covered in ice during the winters, according to Daily Galaxy. The gap or hole remains and is estimated to be the size of Switzerland, and has been named the Maud Rise polynya by people, and has been a huge mystery for scientists worldwide. Experts were confused, as the existence of this phenomenon defied what they knew about polynya. A study published in Science Advances provided insights into how the particular phenomenon was facilitated and sustained in the extreme conditions of this place. 

What is a Polynya?

According to experts, polynyas are patches of water that form within the sea ice, which often occurs in polar regions. It happens due to temperature changes, ocean currents, and atmospheric conditions. These formations are vital in such areas, as they aid in the transfer of heat and oxygen between the ocean and the atmosphere, and maintain marine ecosystems as well as the local climate. Maud Rise polynya stood apart from others due to its size and continued existence. Polynyas are usually temporary occurrences, but in this case, they have somehow survived the test of time. Researchers were unsure which of these factors could be contributing to the longevity of the Maud Rise polynya.

Mystery of Maud Rise Polynya

The Maud Rise polynya was named after a submerged mountain-like feature in the area over which it is located, according to the University of Southampton. Researchers believe that one of the primary reasons behind the rise of the Maud Rise Polynya was the intensification of the Weddell Gyre, a major ocean current from the Southern Ocean. The strong current caused the warmer, saltier, and deeper waters to come to the surface. The mixing of salt and heat from the open sky eventually melts the ice and creates the gap.

Fabien Roquet, a Professor in Physical Oceanography at the University of Gothenburg and co-author of the research, explains that the point of contention for many researchers was that after melting, the salinity of surface water should decrease, and the mixing should stop, and by extension, the gap should also close. However, that doesn't happen. So even if this process created the Maud Rise polynya, something else is helping it to persist. "There must be an additional input of salt from somewhere," Roquet speculated. To understand the secret of sustenance, the team used information from remotely sensed sea ice maps, tagged marine animals, a computational model, and autonomous floats. 

All these methods indicated that when the Weddell Sea current was moving around the Maud Rise plateau, certain turbulent eddies were transporting salt from other places to the top of the submerged structure. From here, a process called "Ekman transport" transferred the salt to the northern flank of the plateau, where the polynya is present. In this process, water moved at a 90-degree angle to the direction of the wind around it. The continuous transport essentially kept the Maud Rise polynya going. "Ekman transport was the essential missing ingredient that was necessary to increase the balance of salt and sustain the mixing of salt and heat towards the surface water," co-author Professor Alberto Naveira Garabato from the University of Southampton explained.

Impact of Maud Rise Polynya

Maud Rise polynya's role in heat exchange and ocean circulation has a huge impact on the surrounding ecosystem. The changes facilitated by the phenomenon encourage processes like deep convection, which enhances ventilation in the ocean's interior. Such events are extremely important for the flourishing of beings living in these places. The species that depend on open spaces for feeding and breeding also benefit from such phenomena. Researchers also believe that a deeper understanding of this formation will allow them to predict the consequences that will be brought forth by climate change in the Southern Ocean. Many experts believe there is a link between the creation of such phenomena and shifting environmental conditions.