BOB HIRSHON (host):
Listening to icebergs. I’m Bob Hirshon and this is Science Update.
This low, restless moan is the song of an Antarctic iceberg, sped up so that humans can hear it. Northwestern University seismologist Emile Okal and his colleagues are studying these strange, ultra-low-frequency melodies with seismic microphones they’ve planted on the ice. Okal says each iceberg resonates on a surprisingly specific note, which fluctuates over time.
EMILE OKAL (Northwestern University):
And this creates a kind of symphony: like, if you slightly adjust the length of a violin string, you’re going to be able to slightly change the musical note that you play.
He says it’s not yet clear what causes the rumbling sounds, but sudden changes in an iceberg’s tune could indicate that it’s cracking internally or breaking apart. So understanding these mysterious songs could help scientists keep tabs on the shrinking polar ice. I’m Bob Hirshon, for AAAS, the science society.