Transcript:

Music
Ambience : Arctic ice groaning, Hungarian lake cracking

Virtually everything is in motion on our planet, although it may be happening at a scale or speed that we're usually not aware of. Take for instance the unexpected sounds of ice. I'm Jim Metzner and this is the Pulse of the Planet. These sounds were recorded on the Arctic Ocean when two huge floes of ice rubbed against each other. Mariana Gosnell is the author of "Ice the Nature, History and the Uses of an Astonishing Substance."

"Frederick Cook, who tried for the North Pole wrote that he kept hearing what sounded like a babies cry. And he traced it to two flows that were kind of abutting each other. And it kept on for a while and then, when the ice had thickened, then it became silent.”

A listener in Hungary sent us these sounds of lake ice cracking and pinging as temperatures dropped.

"When I was living in a little cabin by a lake in New Hampshire, I could hear the ice do really weird things. And most of that is because it's expanding or contracting. And, if a big crack opens up, which usually happened in the middle of the night, when it was contracting, it was just a boom. And I kept thinking there's something happening to my cabin! It's splitting or something. But it often was the ice reacting to the water under it."

Well, then there's the sound that snow and ice make when you walk on them. Typically, the lower the temperature, the higher the squeak.

Ambience: ice walk

We'll hear more about ice in future programs. Pulse of the Planet is made possible by the National Science Foundation. I'm Jim Metzner.