Melting causes accelerated ice loss at tidewater glaciers, releasing pressurized bubbles
ACOUSTICAL SOCIETY OF AMERICA
CREDIT: JOHNSON, VISHNU, AND DEANE
SEATTLE, December 3, 2021 — As the world’s temperatures rise, tidewater glaciers are receding and melting, releasing air trapped in the ice. Scientists can listen to the release of the air and potentially use the sounds to help them gauge the impact of climate change on the ice floes.
During the 181st Meeting of the Acoustical Society of America, which will be held Nov. 29-Dec. 3, Hayden Johnson, from the University of California, San Diego, will discuss how sound can be used to estimate glacial melting induced by climate change. The talk, “Spatial variation in acoustic field due to submarine melting in glacial bays,” will take place Friday, Dec. 3, at 11:45 a.m. Eastern U.S. at the Hyatt Regency Seattle.
Hari Vishnu, from the National University of Singapore, Grant Deane, from the Scripps Institute of Oceanography, and their research team investigated glacial ice melting that releases acoustically distinct pressurized underwater bubbles.
Air trapped with ice below the glacier surface becomes a compressed bubble-ice mixture that builds pressure during the long passage to the glacier terminus. The glacier ice holds ancient bubbles of air that can be up to 20 atmospheres of pressure and generate detectable sounds when they are released as the ice melts.
“We observed that the intensity of the sound generated by a melting terminus tends to increase as the water temperature increases,” said Deane. “This makes sense, because we expect the terminus to melt faster in warmer water, releasing bubbles more rapidly into the ocean and generating more sound.”
The team found as the recording array was moved further from the glacier, the variation in the acoustic melting did not follow a uniform trend.
Moreover, the acoustic intensities at different glaciers clustered in different levels. These observations indicate that the geometry of the glacier-ocean interface, the temperature and salt composition of the underwater sound channels, and the presence of floating ice impact the recorded acoustic measurements.
Their experiments will permit the monitoring of climate change’s impact on glaciers.
“Recording the underwater sounds from a melting terminus will open the door to long-term acoustical monitoring of ice loss, and how it is linked to water temperature,” said Deane. “The endgame here is to establish long-term recording stations for underwater sound around glaciers such as those in Greenland and Svalbard, to monitor their stability over time.”
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Makes a change from all the usual hot air!
I’m guessing that the feminist glaciers screech the loudest.
I remember that silly claim from yesteryear.
So assuming the observations(?) are correct what is the mechanism to connect any of this to climate change/GW. I dont understand. Money????
Money has a lot to do with it.
great, another useless proxy that can be statistically manipulated to enhance the “fear and funding” cycle. I wonder what sort of error bars a local school of farting fish would introduce to the measurements. I am sure there is some research somewhere to link increased CO2 in the atmosphere to an increase farting fish.
Just another pack of useful idiots. Climate science is full of them
I wonder if the sounds of tiny bubbles can be picked up by SOSUS arrays and used to ‘infer’ the temperature of the sea along the acoustic path? Just kidding……
Exactly. What happened to thermometers, that we now have to measure water temperature by proxy?
Or maybe they’re trying to measure the amount of melting and then compare it to temperature, which does sound at least a tiny bit interesting: After all, glacier calving and melting depends not just on temperature but also on how much new snow accumulates at the glacier’s origin and pushes the tongue further into the sea where it melts. But (my own conjecture) this should be measurable by satellite: Stick a flag into the glacier and watch how fast it moves.
“… will open the door to long-term acoustical monitoring of ice loss …”
ie. “My pay check/cheque will be safe for years.”
Ice acoustics…
An infinitely variable ice orchestra comprised near infinite amount highly varying sound generators, without standard distribution of instruments and types, infinitely variable size sound chambers, different sound boards (reflective or vibrating surfaces), different air surface tensions…
Unsurprisingly, different gas combinations change the sound vibrating air emits. As the common joke of people inhaling helium frequently prove.
There is an ocean of difference between gauging glacier stability and measuring amount of glacier melting.
14 years ago, NSIDCs Mark Serreze proclaimed that “the arctic is screaming”. Heh. Now that’s what I call science. He meant that figuratively, but now, the sound of escaping air bubbles could, in a literal sense be the sound of the arctic screaming. Geeze. The planet’s on fire. Imagine what noises it must be making!
A curious mix of “this is what we’re going to do and we’re sure it will work” and “here are the problems we’ve identified so far [which probably means that it won’t]”.
I can add at least one more confounding variable I didn’t see mentioned: salinity.