If you want to find one of the most mysterious things on this planet, go to Antarctica. There, there are water holes in the ice tens of thousands of kilometers wide2 has puzzled scientists for five decades.
These water holes are ice-ball and then dissipate very randomly, regardless of the temperature in the area. There must be something in the sea that contributes to their formation.
Until now, the mystery of these water holes was deciphered by a group of American scientists. They used satellites, robots and especially a team of collaborators who were elephant seals with sensors and antennas on their heads to collect data.
The elephant seals can dive from 600-2,000 m deep into the sea, they are likened to the looms of looms, to weave up a tomography under the Antarctic ice sheet. Since then the new mystery has been revealed.
Sensitive seals help science decipher Antarctic mysteries
Polynya is the term scientists refer to areas of liquid water surrounded by sea ice. In other words, it is the freezing sea areas inside an ice block.
Polynyas began to attract the attention of science since the mid-1970s. That was the time when humans launched into orbit the first Earth-observation satellites, and they captured a picture of a polynya. By New Zealand in Antarctica.
Within a few decades, scientists have noticed a giant and strange polynya hole in the Weddell Sea, northwest of the ice continent. The size and frequency of this giant polynya hole does not correlate closely with temperature. This suggests that there must be a more mysterious and complex mechanism that promotes its very random process.
Until early 2017, the polynya vulnerability created an area of water expansion up to 80,000 km2, about twice the area of the Mekong Delta
Polynya are the freezing sea areas inside an ice block.
To study and decipher the mystery of the hole polynya Weddell, Ethan Campbell, a doctoral student in oceanography at the University of Washington, and colleagues collects satellite data, weather stations, and specifically especially a team of collaborators are elephant seals fitted with antennas on their heads.
These elephant seals serve very well for scientists studying Antarctica, because they often dive as deep as 600 meters below the surface of the ocean, sometimes even exceeding a depth of 2,000 meters.
Elephant seals with sensors on their heads can perform cut-off measurements through the mysterious waters of Antarctica, which lacked the humanity's ability to perform otherwise.
To ensure safety for these elephant seals, scientists only attach the device to their scalp with epoxy. Epoxy will peel off naturally after a few months, or when the elephant seals undergo their annual molt.
Thanks to his special collaborators, scientists have now obtained data showing that the Weddell Sea has experienced unusual storms recently. Salinity of water for some reason also increases.
According to Campbell's team, this is likely to be the two main causes for polynya formation. Both conditions encourage warm seawater to float to the surface, melt the sea ice and create polynya holes.
While salinity and storm intensity vary from year to year, polynya always appears around the same location east of the Weddell Sea. That's because it's on a large mountain in the water called Maud Rise. The ocean currents formed around this mountain create a vortex that concentrates warm water on the bottom of an ice sheet.
Huge polynya pit on the South Pole Weddell Sea
"Research shows that this polynya vulnerability is actually formed by a number of factors, which all must queue together to happen."co-author Stephen Riser, a professor of oceanography at the University of Washington, said. "Any year, you can also see a few of these things happen, but unless you get them all, new holes polynya appear"
The team noted that the climate change crisis affects both the ocean's salinity and the strength of the storm, so it seems likely to affect the Antarctic polynyas.
But scientists still do not know whether global warming will make polynya holes appear more or disappear more. "We need to improve our models so we can study this process, because it can reflect the large-scale consequences of climate change.u, "said Professor Riser.
His research and his colleagues have just been published in the journal Nature earlier this week.