Climate change is studied and measured in a variety of ways. We see ocean levels rising, we feel temperatures getting warmer around the world, but what do we hear?
Scientists around the world have been studying glacier melting by listening to them, and it seems that the glaciers have a lot more to tell us than show us. It’s not an easy task to listen to a glacier, it’s actually an incredibly dangerous line of work. It’s easy to imagine how being close to a giant, melting, wall of ice puts you at risk for massive chunks to break off and crush you or rock your boat quite violently. Once close enough, a hydrophone -underwater microphone - is put in position to start gathering data.
To know what the hydrophone is listening for, small scale tests can be done in a lab with a tiny glacial ice cube. As the cube melts, ancient air bubbles trapped inside get released, pinching off into the water with cute pops and fizzes.
But when we’re talking about glacier fjords we’re certainly not talking about little ice cubes, and when those bubble pops are multiplied by the millions on a larger scale, the oceans sing with pops, cracks, hissing, and crashing that has become one of the loudest ambient noise in the ocean. As these sounds are studied more and more, useful data becomes apparent. More melting means more bubbles, and that means more noise.
Along with the bubbles, microphones will pick up the much more thunderous sounds of sheets of ice crashing into the water. Those glacier walls extend almost all the way to the bottom of the fjord though, and ice breaking off below the water as opposed to above the water can be almost impossible to see. Hydrophones reveal these events, however.
Listening to all these sounds that glaciers make help researchers to understand the speed at which they are melting much more accurately, ultimately giving us more insight into how ice and sea will affect the climate in years to come.
Further Reading & Listening
Thumbnail Photo by: J.casey.oneill, Flickr