The ice shelf's collapse could happen in a few years, researchers warned at a virtual press briefing on Monday at the annual meeting of the American Geophysical Union.
Thwaites glacier in western Antarctica is the widest glacier on the planet, covering about 120 kilometers and extending to a depth of about 3,900 feet. Thwaites is sometimes referred to as the "Doomsday Glacier," as its collapse could cause a cascade of glacier collapse in the frozen continent, and the latest research from the frozen continent suggests that the glacier may be coming for it sooner than expected.
Warming ocean water is melting Thwaites from below and it's also making the seamount unstable because it's loosened the glacier's grip on it. As the glacier weakens, it becomes more prone to surface fractures that could spread until the entire ice shelf shatters "like a car window" as soon as three years from now, researchers said at AGU, held in New Orleans and online.
Time-lapse images of glaciers retreating.
There are some good videos for you.
The Thwaites glacier is changing more dramatically than any other ice and ocean system in the world due to climate change and increased warming in Earth's atmosphere and oceans. Thwaites has lost an estimated 1000 billion tons of ice since 2000 and has lost more ice than it gets in snowfall per year.
If Thwaites were to break up and release all of its water into the ocean, sea levels would rise by more than 2 feet, according to Ted Scambos, a senior research scientist at the Cooperative Institute for Research.
"If it draws the surrounding glaciers with it, it could lead to even more sea-level rise, up to 10 feet 3 m, if it weakens the effect of one ice shelf collapse on other nearby glaciers."
More than 100 scientists in the United States and the United Kingdom are collaborating on eight research projects to observe the glacier from top to bottom, and their results were presented at AGU.
"We're at the halfway point of The International Thwaites Glacier Collaboration," he said. We have a better understanding of the glacier because we have a few more years to assemble further results and integrate them.
The findings of these studies will inform policymakers' strategies for tracking the impacts of glacier melt on sea-level rise over the coming decades, and how that will affect coastal communities around the world.
From below.
Scientists at Thwaites bored holes through the ice to peer at the ocean hundreds of meters underneath, and other researchers used remote-controlled diving robots to study the glacier's grounding zone. They took temperature readings and measured the salt in the ocean to confirm that the waters were warm enough to cause a melt.
A group of scientists found that the ice overhead could interact with the water in the ocean to pump warm water further inland through channels that had already been melted.
The floating ice shelf portion sinks when the tide is low. This lever can pull up a section inland that can pull water in. When the water level rises, the floating section rises up. This up-and-down movement, known as tidal pumping, pulls water farther inland and weakens the glacier.
"hundreds of icebergs"
The glacier's tongue, a part of the ice shelf that protrudes seaward, is now just a loose cluster of Icebergs. The flow of the eastern ice shelf was slowed when the tongue was more solid. Over the past 10 years, the flow of the eastern shelf has shifted due to the loss of resistance. The portion of the shelf that is cracking is likely to shatter into hundreds of pieces within a few years, according to Pettit.
She said that the effect would be similar to a car window, where a few cracks are slowly propagating and then suddenly you go over abump in your car and the whole thing just starts to shatter in every direction.
The appearance of a giant rift on the eastern ice shelf is one of the dramatic changes in Thwaites' ice that scientists are watching in real time. Satellite images show the crack heading right for the spot where the researchers had planned to set up their field site for the season. The researchers nicknamed the crack "the dagger" after seeing its implacable advance, because it wasn't moving fast enough to threaten their field work.
Thwaites' ice shelf is in dire need of repair, but the longterm forecast for the rest of the glacier is not certain. The collapse of the shelf will likely cause the glacier's flow to accelerate in its rush toward the ocean, with parts of it potentially tripling in speed. The time frame for those changes will be decades rather than a few years, according to the briefing.
The ITGC teams will continue to monitor and analyze changes in the interplay between glacier, ice shelf and ocean on Thwaites to help world leaders and policy makers prepare for what comes next.
"That will help us understand what the next century is going to be like from this part of the world," he said. Changes in Thwaites Glacier are what we think will lead it.
Live Science published the original article.
