New NASA research on Antarctica, including the first ever map of iceberg calving, sounds all the alarm bells by doubling previous estimates of ice shelf loss.
Antarctica’s Thwaites Glacier , popularly known as the ‘end of the world’ glacier, nicknamed for its high risk of collapse and threat to global sea level, empties into the Amundsen Sea and… it ‘s on edge. Scientists have amplified concerns about the extreme rise in sea level that would accompany their potential demise.
How is the continent changing?
The potential impact of its potential ice retreat is huge because the complete loss of Thwaites and its surrounding icy basins could raise global sea levels by up to 3 meters.
The new study, published in Nature Geoscience, shows that Antarctica’s Thwaites Glacier is “grabbing with its fingernails”, after discovering that the ice has retreated twice as fast as previously thought in the last 200 years.
Two studies led by researchers at NASA’s Jet Propulsion Laboratory (JPL) in Southern California show new and unexpected data on how the Antarctic ice sheet has been losing mass in recent decades. In the most recent, scientists found that the edge of the ice sheet has been shedding icebergs faster than ice can be replaced, doubling previous estimates of ice loss from Antarctica’s floating ice shelves. since 1997, from 6 billion to 12 billion metric tons.
Ice loss from calving has weakened ice shelves, allowing Antarctic glaciers to flow more rapidly into the ocean and accelerating the global rate of sea level rise.
Stunning high-resolution mapping images of a critical area of seabed off Thwaites Glacier show geological features that are new to science and also provide a kind of crystal ball for seeing the future of the ‘doomsday glacier’. according to experts from the College of Marine Sciences at the University of South Florida.
there could be big changes
The team documented more than 160 parallel ridges that were created, like an imprint, as the leading edge of the glacier retreated and rose and fell with daily tides. At some point in the last 200 years, during a period of less than six months, the glacier front lost contact with a seafloor ridge and retreated at a speed of more than 2.1 km, twice the documented speed. using satellites between 2011 and 2019.
In recent decades, ocean warming has been destabilizing the Antarctic ice shelves by melting them from below, making them thinner and weaker . Because calving losses have largely outpaced the natural growth of the ice shelf, the researchers believe it is unlikely that Antarctica will be able to grow back to its pre-2000 extent by the end of this century.
“Antarctica is falling apart,” said Chad Greene, lead author of the study. “And when ice shelves shrink and weaken, the continent’s massive glaciers tend to accelerate and increase the rate of global sea level rise.”
According to the United Nations, approximately 40 percent of the human population lives within the first 100 kilometers of the coast. A change in sea level of these characteristics would cause massive migrations of all these coastal populations.
Referencia: “Antarctic calving loss rivals ice-shelf thinning” by Chad A. Greene, Alex S. Gardner, Nicole-Jeanne Schlegel and Alexander D. Fraser, 10 August 2022, Nature.
DOI: 10.1038/s41586-022-05037-w
