Dust stored in glacier ice holds a record of climate change

Researchers from The Ohio State University are using dust trapped in glacier ice to document past changes in Earth’s climate system and help predict future changes. The study helps to understand how dust affects, and is affected by, climate. 

Ice cores, which are very well preserved, provide comprehensive archives of Earth’s climate system. These natural time capsules allow scientists to picture what the world looked like at the time, and understand aspects such as levels of greenhouse gas concentrations, and volcanic, solar and biological activity. 

This study collected samples from the Guliya Ice Cap in Northwestern Tibet, home to one of the largest atmospheric dust source regions in the Northern Hemisphere. Westerly winds in this region blow dust toward big cities in East Asia. In 2021, China experienced its largest dust storm in a decade, raising concerns about the effects of climate change. During the storm, entire cities to take shelter.

The team examined dust particles locked inside ancient ice, or what study co-author Emilie Beaudon calls “cryo-dust.”

“By looking at dust composition through the ice, we can extract information about Earth’s environmental condition at the time the snow was deposited and the ice was formed,” said Beaudon. “We might be able to learn if it was a relatively dry or wet period or try to infer where the dust originally came from, and thereby obtain information on past atmospheric influences.”

The findings show that dust composition can vary greatly in the same glacier. This suggests that a complete dust record could provide scientists with much more information.

Dust stirred up by strong winds can cause chain reactions in the atmosphere, affecting human health and marine biochemistry and the balance of carbon dioxide. How these microparticles affect the surrounding atmosphere is dependent on their size, shape and chemical makeup. 

But researchers need a lot of ice to be able to collect that data. Scientists do not have enough data to help identify how Central Asian desert dust is transported over long distances and changes over time. 

Studying a dust record from a Tibetan ice core is one of the only ways to provide a long-term perspective on the Central Asian dust cycle, Beaudon said. 

The ancient Guliya glacial is a prime candidate for deeper exploration. Eventually, the research team hopes this work will help investigate glacial records of other planets. “If there are ever ice cores drilled or samples taken from Mars or any other planet, I hope to study them.” Beaudon said. 

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By Katherine Bucko, Earth.com Staff Writer

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