Navigation Links
Glaciers sizzle as they disappear into warmer water
Date:11/27/2013

SAN FRANCISCO, Nov. 27, 2013 Scientists have recorded and identified one of the most prominent sounds of a warming planet: the sizzle of glacier ice as it melts into the sea. The noise, caused by trapped air bubbles squirting out of the disappearing ice, could provide clues to the rate of glacier melt and help researchers better monitor the fast-changing polar environments.

Geophysicist Erin Pettit, a researcher at the University of Alaska, had often heard popping, crackling sounds while out kayaking in the frigid northern waters. The sounds were also picked up by underwater microphones Pettit set up off the Alaskan coast, and at a much louder volume than above the surface.

"If you were underneath the water in a complete downpour, with the rain pounding the water, that's one of the loudest natural ocean sounds out there," she said. "In glacial fjords we record that level of sound almost continually."

While Pettit suspected the din was caused by melting ice, she couldn't confirm that hypothesis without a more controlled experiment. So she enlisted the help of Kevin Lee and Preston Wilson, acoustics experts from the University of Texas. Pettit sent the Texas researchers chunks of glacier, which they mounted in a tank of chilled water. Lee and Wilson recorded video and audio of the ice as it melted and were able to match sounds on the recording to the escape of bubbles from the ice.

"Most of the sound comes from the bubbles oscillating when they're ejected," Lee said. "A bubble when it is released from a nozzle or any orifice will naturally oscillate at a frequency that's inversely proportional to the radius of the bubble," he said, meaning the smaller the bubble, the higher the pitch. The researchers recorded sounds in the 1 3 kilohertz range, which is right in the middle of the frequencies humans hear.

Scientists have known for decades that the bubbles in glaciers form when snow crystals trap pockets of air and then get slowly squashed down under the weight of more snow. As the snow is compacted it turns into ice and the air bubbles become pressurized. The regular way the bubbles form means that they are evenly distributed throughout the ice, an important characteristic if you want to use the sound intensity of bubble squirts to measure ice melt rate.

While the symphony of melting ice might not carry the same emotional wallop as images, sound still has its own, sometimes very loud, story to tell. Pettit and Lee say they could imagine using hydrophone recordings in glacial fjords to monitor relative changes in glacier melting in response to one-time weather events, seasonal changes, and long-term climate trends. Because sound travels long distances underwater, recording microphones can be placed a safe distance from unstable ice sheets. The audio recordings would complement other measurements of ice melt, such as time-lapse photography and salinity readings.


'/>"/>

Contact: Jennifer Lauren Lee
jlee@aip.org
301-209-3099
American Institute of Physics
Source:Eurekalert

Related biology news :

1. Melting glaciers, enough sand to bury London, and ancient ecosystem engineering
2. Analysis of speed of Greenland glaciers gives new insight for rising sea level
3. Old aerial photos supply new knowledge on glaciers in Greenland
4. Alpine glaciers contribute to carbon cycling
5. Himalayan glaciers will shrink even if temperatures hold steady
6. Significant contribution of Greenlands peripheral glaciers to sea-level rise
7. Disappearing grasslands: ASU scientists to study dramatic environmental change
8. Disappearing bacterium may protect against stroke
9. Prairie dogs disperse when all close kin have disappeared
10. International collaboration to investigate disappearing reptiles and amphibians
11. Dinosaur-era climate change study suggests reasons for turtle disappearance
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:1/22/2016)... Jan. 22, 2016 ... of the "Global Biometrics Market in ... offering. --> http://www.researchandmarkets.com/research/p74whf/global_biometrics ) ... "Global Biometrics Market in Retail Sector 2016-2020" ... --> Research and Markets ( http://www.researchandmarkets.com/research/p74whf/global_biometrics ...
(Date:1/20/2016)... 20, 2016 A market that just keeps ... from the explosion in genomics knowledge. Learn all about ... A range of dynamic trends are pushing market growth ... medicine - pharmacogenomics - pathogen evolution - next generation ... - greater understanding of the role of genetic material ...
(Date:1/20/2016)... 20, 2016  Synaptics Incorporated (NASDAQ: SYNA ... today announced sampling of S1423, its newest ClearPad ... small screen applications including smartwatches, fitness trackers, and ... and rectangular shapes, as well as thick and ... moisture on screen, while wearing gloves, and supports ...
Breaking Biology News(10 mins):
(Date:2/12/2016)... 12, 2016 MedGenome,s Commitment ... Scientific Understanding of Complex Diseases Such as Cancer, ... --> --> MedGenome, ... and a leading provider of genomics research services ... to the GenomeAsia 100K consortium as a founding ...
(Date:2/11/2016)... NEW YORK , Feb. 11, 2016  Bioethics International, ... how medicines are researched, developed, marketed and made accessible to ... BMJ Open had named the publication of the ... for 2015. The publication is also featured as one of ... published in the last year that are most frequently read. ...
(Date:2/11/2016)... , February 11, 2016 ... Corporation ("PositiveID" or "Company") (OTCQB: PSID), a life ... today that its Thermomedics subsidiary, which markets the ... its growth plan in January 2016, including entering ... increasing sequential monthly sales growth, and establishing several ...
(Date:2/10/2016)... MONTREAL , Febr. 10, 2016 /PRNewswire/ - BioAmber Inc. ... is pleased to announce that Mitsui & Co. Ltd., ... bio-based succinic acid plant, is investing an additional CDN$25 ... equity, increasing its stake from 30% to 40%.  Mitsui ... of bio-succinic acid produced in Sarnia ...
Breaking Biology Technology: