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What began as a quest to watch the activity of the largest ice shelf in Antarctica has changed to hear it.
On Tuesday (October 16), researchers led by a team at Colorado State University published a letter describing an accidental discovery (paywall) on the Ross ice floe: when they used sensitive seismometers to study the ground under the immense d Spain), they discovered that they could also pick up a sound frequency emitted by the snow when it vibrated under the effect of wind and melting.
"We discovered that the plateau almost continuously sung at frequencies equal to or greater than five cycles per second, "the researchers write (stress theirs). Although these frequencies are too low for humans to hear naturally, when sounds are accelerated, they sound like the sneaky and disturbing introduction of a monster into a horror movie.
The team had initially placed 34 seismometers in the snow a few meters deep on the Ross ice floe in 2014. In two years, they noted the weak rumblings caused by the movement of shallow snow, called "firn", which rests on the ice. "It's like having a flute on the ice all the time," said Julien Chaput, a geophysicist at the University of Texas in El Paso, in a statement. Temperature changes and the creation or destruction of snow dunes on the surface following storms change the frequency with which the snow vibrates, much like playing different notes on an instrument.
Towards the end of the two-year period, the team noticed a drop in the pitch of the sounds, corresponding to a warm period in which some of the snow had melted. Subsequently, the tone remained lower, suggesting that the damage caused by these warmer periods can last a long time. The team believes that vibration monitoring could provide real-time insight into ice pack activity to help predict whether it is about to calve. Historically, scientists have struggled to predict when icebergs will separate from their shelves.
"Nest melt is widely considered to be one of the most important factors in the destabilization of pack ice, which in turn accelerates the flow of ice into the ocean from the ice sheets," Chaput told Earther. . Acoustically monitoring the fnn fusion rate could be a way (literally) of alarming scientists when the plateau could become unstable.
Given that if one of the large Antarctic ice shelves melted, the sea level would rise considerably, perhaps making the disturbing tone of the snow vibrate.
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