Warming ice sounds intact
istock_glacier-calving.jpg
The researchers were able to hear ice
shelfs calving using ocean listening
stations.
Image: iStockphoto

A Curtin University team reports that climate change does not appear to have significantly hastened disintegration of the Eastern Antarctica ice shelf, based on their acoustic monitoring of the region.

In a presentation to the third international Underwater Acoustic Measurements conference in Greece recently, Associate Professor Alexander Gavrilov told the audience that Curtin researchers would continue to analyse noise recorded at ocean listening stations.

“More than six years of observation has not revealed any significant climatic trends,” Assoc. Prof Gavrilov said.

The associate professor and fellow researcher PhD student Binghui Li found that the frequency and intensity of noise events from Antarctica’s east follows a strong seasonal cycle.

Assoc. Prof Gavrilov said that acoustic data provided by Geoscience Australia allowed researchers from the university’s Centre for Marine Science and Technology to monitor sounds from East Antarctica.

“We can observe only about one-third of the Antarctica coast, namely the eastern Antarctica shelf, from the Cape Leeuwin and Chagos underwater listening stations in the Indian Ocean.

“However, we have observed and recorded noise from some large events in eastern Antarctica – for example, ice calving from the Shackleton ice shelf in spring 2007.”

The physicist says the researchers are not able to observe events in western Antarctica which includes the largest ice shelves – Ross, Ronnie, Larsen and Wilkins.

Earlier this year, the European Space Agency revealed dramatic satellite images of Wilkins ice shelf where than 700 hectares was lost in April after an ice bridge shattered.

More than six years ago, Assoc. Prof Gavrilov suggested that noise sensors from nuclear-test listening stations could be used to watch for the disintegration of the Antarctic ice shelf, an indicator of global temperature change.

So far, noise data recorded between November 21, 2001, and January 7, 2008 has been analysed.

Assoc. Prof Gavrilov said the response of the conference to the Antarctic research was very positive, with the most frequently asked question being whether the Curtin researchers would continue their observations.

“This monitoring process is a very promising way to watch the climate in action and we will continue to do so.”

Click here, here and here to listen to samples of the noises being analysed.


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