Home Opinion and Features Global warming threatens Antarctica’s meteorites

Global warming threatens Antarctica’s meteorites

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Antarctica is home to Earth’s largest concentration of meteorites – so many that over 60 percent of meteorite finds originate there. But global warming is endangering Antarctica’s meteorites, and a new analysis forecasts that close to three-quarters of the continent’s meteorites could disappear from the ice sheet surface by century’s end, making it nearly impossible to spot or retrieve the precious space rocks.

A meteorite on the blue ice field in the Miller Range, Antarctica. File picture: Nasa, Cindy Evans

By Erin Blakemore

ANTARCTICA is home to Earth’s largest concentration of meteorites — so many that over 60 percent of meteorite finds originate there. But global warming is endangering Antarctica’s meteorites, and a new analysis forecasts that close to three-quarters of the continent’s meteorites could disappear from the ice sheet surface by century’s end, making it nearly impossible to spot or retrieve the precious space rocks.

The research, published in Nature Climate Change, used a machine-learning algorithm to project how Antarctic meteorites will fare under simulated climate conditions. Antarctica’s meteorites built up in stranding zones on the continent thousands of years ago, becoming embedded in ice. Today, they are usually found in “blue ice” areas — pockets where wind reveals older ice that looks blue in contrast with the continent’s large expanses of white.

Meteorites are particularly sensitive to temperature, the researchers explain, and when they are exposed to the sun, their darker surface warms, which can melt the ice beneath and cause them to sink away from the ice surface.

The researchers project that in all emissions scenarios, at least 5,000 meteorites a year will disappear from the surface. Every tenth of a degree of temperature increase is correlated with a loss of between 5,100 and 12,200 meteorites, and under a high-emissions scenario, 76 percent of the areas currently covered by meteorites will be lost.

This would represent a catastrophic loss to space scientists, who prize meteorites because of the information they contain about the development of our solar system. Since they formed up to billions of years ago, the space rocks offer important clues about stars, planetary formation, and even Earth’s geologic history.

As a result, the researchers say, it’s important to “rapidly and purposefully” collect as many such specimens as possible before they become inaccessible to science.

“We need to accelerate and intensify efforts to recover Antarctic meteorites,” Harry Zekollari, a glaciologist who led the research while working at ETH Zurich’s department of civil, environmental and geomatic engineering, said in a news release. “The loss of Antarctic meteorites is much like the loss of data that scientists glean from ice cores collected from vanishing glaciers — once they disappear, so do some of the secrets of the universe.”

– THE WASHINGTON POST

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