There is a huge Antarctic glacier, which causes concern among scientists since its melting could raise sea levels by up to 60 centimeters across the planet.
The concern of the most famous glaciologists is supported by the fact that the risk is based on the enormous frozen mass of 192,000 km², almost similar to the size of Uruguay (176,215 km²)is much more exposed to warm ocean waters than previously believed.
He Thwaites Glacier, the widest in the world, rises and falls with the daily tides. As it rises, warm sea water shoots farther beneath the ice than scientists thought: up to 6 kilometers, according to satellite data. Experts say this could significantly increase the melting area of the glacier.
The degradation of Thwaitespopularly known as the “doomsday glacier“, means that the warm ocean could further devour the ice sheet of the West Antarctica and bring with it the possibility of massive sea level rise.
“Water is capable of penetrating under the ice to much greater distances than we thought,” he said. Eric Rignotscientist of the University of California in Irvine and NASA Joint Propulsion Laboratorywho led recent research published in Proceedings of the National Academy of Sciences.
The team of the University of California Irvine confirmed widespread contact between ocean water and the glacier, a process that is replicated throughout Antarctica and Greenland, which causes “vigorous melting” and may require a reevaluation of global projections of sea level rise.
The glaciologists relied on data collected from March to June 2023 by the Finnish commercial satellite mission ICEYE. These satellites form a “constellation” in polar orbit around the planet, using InSAR (synthetic aperture interferometer radar) to persistently monitor changes on the Earth’s surface.
Many passes of a spacecraft over a defined small area produce smooth data results. In the case of this study, it showed the rise, fall and curvature of the Thwaites Glacier.
“This ICEYE data provided a series of long-term daily observations that closely fit tidal cyclessaid lead author Rignot, a professor of Earth system science at UC Irvine. “In the past, we had some data available sporadically, and with just those few observations it was difficult to know what was happening,” he added.
Rignot’s research team had previously documented this extensive tidal pulsation of seawater on the Petermann Glacier, one of the largest ice outlets in Greenland. But Thwaites makes Petermann look small. It is 128 kilometers wide where it touches the ocean, compared to 16 kilometers at Petermann.
Thwaites It is currently stuck to the ocean floor by two oceanic ridges located under the glacier. But when the tide lifts the glacier, according to the new research, sea water passes over or around one of them. If the glacier were to break away from these ridges, the warm water of the ocean would enter an area in which the seabed descends towards very deep regions, towards the center of the West Antarctica.
The new study “confirms that this process of pushing water upwards beneath the glacier is occurring, which has been observed with some other techniques, but never with this dynamic resolution,” he says. Britney Schmidtscientist of the Cornell University which has studied an underwater region and under the ice of the “doomsday glacier”, of similar depth, using a submersible robot, called Icefin.
Schmidt states that the ability of water to run off in this way, even up a slope to which ice has become attached, is a new factor that increases the instability of the glacier. In the past, scientists have mainly emphasized that glaciers retreat rapidly when they climb downhill slopes. Today, the Thwaites does this while tied to an upward slope.
In the so-called support line, the border between the ice that rests on land and that floating in the sea, its thickness is 800 to 1200 meters, and flows towards the sea at a speed of about 2 kilometers per year. The ice flows into the bay of Pine Island, in the Amundsen Sea, along with that of the neighboring Pine Island glacier, the one that advances the fastest on the entire continent and the one that dumps the most ice into the sea in the entire world, responsible for a quarter of the ice lost by Antarctica.
During the last Ice Age, Thwaites grew monstrously and dug a channel beneath himself as he moved along the continental shelf.
Today, near its end, it rests on bumps and ridges on the seabed, to which the ice adheres, creating resistance and helping to contain the otherwise smoothly flowing glacier. Glaciologists have long worried that the deep currents of warm water surrounding Antarctica could seep into the channel below.
He glaciologist Slawek Tulaczyk, of the University of California Santa Cruz, began wondering years ago whether the water could be drained from beneath a large glacier like Thwaites. He imagined drilling into its subglacial lakes to pump water out of them, gushing from the pump outlets and freezing into tiny crystals before it splashed onto the Antarctic surface, “like a snow gun.”
The remaining water beneath the ice would likely flow into empty lakes, drying out parts of the bottom of the glacier. Hopefully, a cooling feedback loop would be activated. Under this plan, intended as “Antarctic ice preservation,” the Thwaites Glacier would freeze in place and a catastrophic rise in sea level would be avoided.
Instead of enveloping the Earth in a layer of aerosols to obscure the sun, he simply wants to intervene on the glacier. Yours is just one of the preservation plans that glaciologists are considering. Another team of scientists has suggested that astonishingly large swaths of insulating fabric could be placed over vulnerable glaciers to keep them cold. Additionally, one group has proposed extending a curtain, made of plastic or some other material, across the 75-mile-wide zone where Thwaites meets the sea, to divert warm water flowing beneath it.
Glaciologist John Moore, from the University of Lapland, proposed building a 100-meter-high wall on the seabed to stop the melting of the ice in Greenland. He also suggested creating 300 meter artificial islands to block the Thwaites and Pine Island glaciers. Now, his new proposal is to install 100 kilometer-long underwater curtains, anchored to the seabed, to prevent warm water from reaching the Thwaites.
With an estimated cost of 50 billion dollars, this geoengineering project It seems almost impossible. However, Moore and his collaborators at the University of Cambridge are testing the idea with 1-meter curtains in laboratory tanks. They plan to design a prototype to test in 2025 in the Cam River, followed by another larger than 10 meters in a Norwegian fjord.
“Thwaites is the most unstable place in Antarctica and contains the equivalent of 60 centimeters of sea level rise. The concern is that we are underestimating the speed at which the glacier is changing, which would be devastating for coastal communities around the world,” said the glaciologist. Rignot .
Thwaites has been in a retreat for centuries that began to accentuate in the 1940s due to the El Niño phenomenon. According to the Thwaites Glacier International Collaboration, a project co-financed by the US and the United Kingdom, in the last 30 years the amount of ice dumped into the sea has doubled; Every year it loses 50 billion tons more ice than it receives from snowfall. Since 2000 it has lost more than a billion tonnes, and its height is reducing by one meter a year.
