Anyone who’s seen Star Wars will probably recognize that characteristic “pew pew” of a laser gun. Starting out high-pitched before rapidly dropping low, it’s both a very distinct and very unnatural sound. But you may be surprised to learn that if you drop a hydrophone in a frozen lake right here on Earth, you can hear what sounds like the Battle of Hoth.
This is singing ice, and the way it works is deceptively simple. Simply put, no medium propagates sound like water. It’s how whales can sing to one another across even vast distances and why phenomena like “the Bloop” can be heard 2,000 miles apart across the Pacific.
When cracks and fractures form in a sheet of ice (often because of significant temperature changes, so spring and fall are the best times to hear it), they release energy in the form of vibrations. Those vibrations cover a range ...
