Antarctica is ‘singing’ — and its song could tell us about melting ice shelves
Scientists who set out to watch the ice shift in Antarctica have ended up listening to it instead.
The team of researchers published a letter that details how they found out that ice shelves on the southern continent are producing low-frequency waves.
“We discovered that the shelf nearly continuously sings at frequencies of ﬁve or more cycles per second,” the letter states.
The waves are too slow to hear by human ears, but the scientists sped them up to illustrate their point.
The sound was measured by a team of scientists who placed seismic sensors under the snow on the Ross Ice Shelf, in order to monitor the structure and movement of the ice.
The snow provides a barrier between the air and the ice, which insulates it from warming temperatures, comparing it to a fur coat.
When they looked at the data, they realized the top layer of the shelf (called the firn) was almost constantly vibrating, thanks to the winds travelling atop the snow dunes.
“Chasing down that lead gave us a unique insight into all the environmental effects an ice shelf can ‘feel,’ and on remarkably short time scales,” said lead researcher Julien Chaput, geophysicist and mathematician at Colorado State University.
The sound changes as weather conditions changes, which the researchers say can track changes such as storms, and more importantly, changes in air temperatures.
“Basically, what we have on our hands is a tool to monitor the environment, really. And its impact on the ice shelf.”
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Being able to monitor the air temperature is particularly important, Chaput explained, because it could tell us which ice shelves are vulnerable to warming events.
Melting of the snow is considered one of the most important factors in the destabilization of an ice shelf, which can accelerate the process of the shelf slipping into the ocean.
“Losing an ice shelf is something of a catastrophe,” he said, because it stabilizes nearby ice sheets that “are the true heavy hitters in sea level rise.”
Chaput told Global News that currently, ice shelf monitoring is limited to satellite sweeps, which are few and far between.
But if we deployed seismic sensors on more ice shelfs, you could observe subtle environmental changes, in minutes.
He hopes that adding more seismic sensors can monitor other ice shelves — especially the vulnerable ones.
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