Why Does a Frozen Lake Sound Like a Star Wars Blaster?

Visitors to icy lakes are sometimes treated to the sounds of a space age battle. Learn why in this NPR video. (Credit Cory Williams "Live Each Day" YouTube Channel.)

When Cory Williams moved from California to Alaska he skipped rocks across the ice-covered surface of Edmonds Lake and was wowed by the "coolest sound ever". The sci-fi like sounds have been observed in lakes across the world. They usually occur when there are fluctuations in temperature which make the ice expand and contract. This ice shifting causes a variety of sound frequencies both low and high. The high frequencies move through the ice faster so you hear them first. You have to be the right distance away to hear the sound as the high frequencies overrun the low frequencies. Learn more about this in this fascinating video with National Public Radio's Skunk Bear. Apparently those iconic Star Wars blaster sounds were produced by making use of the same frozen lake acoustics. Very cool!