The "whistling" of the Ross Ice Shelf, Antarctica's largest, is beautifully eerie. It's also potentially a divining rod for changes to shelves' composition that can be monitored in real time.
To arrive at their new recording, twelve scientists working on the ice shelf burrowed 34 tools for measuring seismic activity into it, expecting to monitor its internal vibrations. They noticed, however, that surface wind glazing over the "firn" — the top layer of snow of the shelf — was feeding the sensors below.
What was at first considered to be "inconvenient ambient noise," as the glaciologist Douglas R. MacAyeal put it in a summation of the new findings, ended up yielding valuable insights about the health of the shelf itself. The shelf's song changes as its surface does; strong storms can rearrange the snow dunes atop it, causing that ice to vibrate at different frequencies — how fast the seismic waves travel through the snow changes as air temperatures at the surface fluctuate, in turn giving scientists data on the shelf's structural integrity. Meaning whether or not it will break up, and thus raise sea levels. Not bad for a whistle or two. Or 34.