March 24, 2023

lose one Florida-sized glacier Antarctica could wreak havoc on the world as scientists predict it will raise global sea levels by as much as 10 feet. It’s already melting rapidly — and its collapses are likely to only increase rapidly in the coming years, scientists say.

Thwaites Glacier is the widest glacier on Earth 80 miles wideBut as the planet continues to warm, its ice, like most of the sea ice around the planet’s poles, is melting.The rapidly changing state of the glacier has worried scientists for years because The ‘creepy’ global impact So much extra water has been added to Earth’s oceans that it has given rise to the nickname “doomsday glaciers.”

Thor scientists look in awe as thwaites-glacier-margin.jpg of crumbling ice
Thwaites Offshore Research (THOR) scientists Alastair Graham (right) and Robert Larter (left) look in awe at the crumbling ice on the edge of the Thwaites Glacier from the deck of the R/V Nathaniel B. Palmer.

Frank Nitsche/University of South Florida

To better predict what will happen to the glacier, and how soon it will die, the researchers took a closer look at the grounding zone, where the glacier’s ice transforms from a crutch on the ocean floor to a floating shelf.This “key area” in front of the glacier provides historical data on the glacier’s past retreat rate, and according to The study, led by marine geophysicist Alastair Graham of the University of South Florida, “provides a kind of crystal ball” for Thwaites’ future.

The findings were published in natural geosciences on Monday.

Looking at the 160 parallel ridges that formed as the glaciers retreated and moved along the floor, the scientists found that the glaciers have recently tracked a slower rate of retreat than they have sometimes been in the past. At some point in the past 200 years, over a period of 5.5 months, scientists found that the glacier was retreating at a rate of more than 2.1 kilometers (1.3 miles) per year—twice the distance it receded between 1996 and 2009, the rate at which it receded tripled from 2011 to 2017.

While this may seem like a positive sign, it’s actually a sign that things may speed up soon. “In the near future, a similar pulse of rapid withdrawal may occur,” the study said.

Screenshot 2022-09-06-at-7-46-51-am.png
The researchers created images showing how the melting of Thwaites Glacier forms ribbed parallel lines along the seabed as an indicator of how fast it is erasing.

natural geosciences

Study co-author Robert Larter, a marine geophysicist with the British Antarctic Survey, wrote in a paper Press Releases“We should expect to see large changes on small timescales in the future — even from one year to the next — once the glacier retreats beyond the shallow ridges on its bed.”

Lead author Alastair Graham, of USF’s School of Marine Sciences, said: “Our results suggest that there has been a very rapid retreat pulse of Thwaites Glacier over the past two centuries, possibly as recently as the 20th century. mid-century.”

The thinner the glacier, the less time it takes for another expanding melt event to occur, with recent observations of the glacier raising the odds of such an event happening “in the coming decades,” the study said.

Not even a year ago, scientists warned that Thwaites’ last ice shelf — the only support that would keep it from collapsing completely — might only hold a in a few yearsThe warm water seeping from beneath the massive ice block is the main cause of its melting and could lead to the eventual collapse of the continental shelf in as little as five years.

warm water First discovered in 2020 in the grounding zone at the base of the glacier.The year before, the researchers also discovered a huge cavity Beneath the glacier is almost the size of Manhattan.

“A little kick against Thwaites could have a big repercussion,” Graham said.

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