What innovative ideas will help stop the melting of the world’s largest glacier?
There is a huge Antarctic glacier which is the cause concern among scientists as its melting could raise sea levels by 60 centimeters across the planet.
The concern of the most famous glaciologists is reinforced by the fact that the basis of the risk lies a huge frozen mass with an area of 192,000 km², almost the size of Uruguay (176,215 km²).much more exposed to warm ocean waters than previously thought.
He Thwaites Glacier, the widest in the world, rises and falls with the daily tides. As the warm sea water rises, it is carried further under the ice than scientists expected: according to satellite data, 6 kilometers. Experts say this can significantly increase the melting area glacier.
Degradation Thwaitescommonly known as “doomsday glacier“, means that warm ocean may be further absorbed by the ice sheet West Antarctica and would entail the possibility of significant sea level rise.
“Water can penetrate much greater distances under the ice than we thought,” he said. Eric Rignoscientist University of California in Irvine and NASA Joint Propulsion Laboratorywho led a recent study published in Proceedings of the National Academy of Sciences.
Team University of California at Irvine confirmed widespread contact between ocean water and glacier, a process that is repeated across Antarctica and Greenland, which is causing “vigorous melting” and may require a reassessment of global sea level rise projections.
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 (Interferometric Synthetic Aperture Radar) to continuously monitor changes on the Earth’s surface.
Multiple passes of the spacecraft over a specific small area produce smoothed data results. In the case of this study, it showed the rise, fall and curvature of the Thwaites Glacier.
“This data from ICEYE was provided by a number of long-term daily observations that closely match tidal cyclessaid lead author Riño, a professor of Earth system sciences at the University of California, Irvine. “Previously, some data was available sporadically, and with just these few observations it was difficult to understand what was happening,” he added.
Rigno’s research team previously documented this extensive tidal pulsation of seawater at the Petermann Glacier, one of the largest glaciers in Greenland. But Thwaites makes Petermann look small. Its width at the point of contact with the ocean is 128 kilometers, compared to 16 kilometers at Petermann.
Thwaites It is currently glued to the ocean floor by two oceanic ridges located beneath the glacier. But according to a new study, when the tide lifts a glacier, seawater flows over or around one of them. If a glacier were to break away from these ridges, warm ocean water would enter an area where the seafloor drops to very deep areas, towards the center West Antarctica.
The new study “confirms that there is a process of pushing water up beneath the glacier, which has been observed with some other methods, but never with this dynamic resolution,” he says. Britney Schmidtscientist Cornell University which explored the underwater region and under the ice of the “Doomsday Glacier” of similar depth using the Icefin submersible robot.
Schmidt claims that the ability of water to flow in this way even up a slope to which ice has adhered, is a new factor increasing glacier instability. Previously, scientists mainly emphasized that glaciers retreat quickly as they rise up slopes. Today Thwaites does it while tied to an upward slope.
In the so-called support line, the boundary between ice lying on land and ice floating in the sea, its The thickness ranges from 800 to 1200 meters and flows towards the sea at a speed of about 2 kilometers per year. The ice flows into Pine Island Bay in the Amundsen Sea along with the neighboring Pine Island Glacier, which is advancing the fastest on the entire continent and dumping the most ice into the sea in the entire world. , responsible for a quarter of the ice lost by Antarctica.
During the last Glacial period, Thwaites grew monstrously and dug a channel underneath itself, moving along the continental shelf.
Today, approaching its end, it rests on irregularities and ridges of the seabed, to which ice sticks, creating resistance and helping to hold back the smoothly flowing glacier. Glaciologists have long been concerned that deep currents of warm water surrounding Antarctica could seep into the channel below.
He glaciologist Slavek Tulacik, from the University of California, Santa Cruz, began wondering years ago whether it was possible to pump water out from under a glacier as large as Thwaites. He imagined drilling into subglacial lakes to pump out water that would gush from pump outlets and freeze into tiny crystals before splashing out onto the Antarctic surface “like a snow cannon.”
The remaining water under the ice will likely flow into empty lakes, drying out parts of the glacier floor. Hopefully the cooling feedback loop will be activated. Under this plan, intended to “conserve Antarctic ice”, the Thwaites Glacier would freeze in place and catastrophic sea level rise would be avoided.
Instead of blanketing the Earth in a layer of aerosols that block out the sun, it simply wants to interfere with the glacier. Yours is just one of conservation plans being considered by glaciologists. Another group of scientists has suggested that surprisingly large pieces of insulating fabric could be placed over vulnerable glaciers to keep them cool. In addition, one group has proposed extending a curtain made of plastic or other material across the 75-mile wide area where Thwaites meets the sea to divert warm water flowing underneath.
Glaciologist John Moore from the University of Lapland has proposed building a 100-meter-high wall on the seabed to stop the melting of Greenland’s ice. He also proposed creating 300m artificial islands will block Thwaites and Pine Island glaciers. Now their new proposal is to install 100 kilometer long underwater curtains anchored to the seabed to prevent warm water from entering Thwaites.
At approximate cost 50 billion dollars, this geoengineering project It seems almost impossible. However, Moore and his colleagues at the University of Cambridge are testing this idea using 1-meter curtains in laboratory tanks. They plan to develop a prototype for testing in 2025 on the River Cam, and then another, measuring more than 10 meters, in a Norwegian fjord.
“Thwaites is the most unstable place in Antarctica, with sea levels rising by 60 centimeters. The concern is that we are underestimating the rate of glacier change, which will have devastating consequences for coastal communities around the world,” the glaciologist said. Rigno .
Thwaites lived in seclusion for centuries, which became especially noticeable in the 1940s due to the El Niño phenomenon. According to the Thwaites International Glacier Collaboration, a project jointly funded by the US and UK, the amount of ice dumped into the sea has doubled in the last 30 years; Every year it loses 50 billion tons more ice than it receives from snowfall. It has lost more than a billion tons since 2000, and its height is decreasing by one meter per year.