Listen: Why do Minnesota lakes make freaky noises this time of year?

Walking along Minnesota’s lakes this time of year can startle anyone with sounds straight out of a “Star Wars” shootout.

Freezing waterways can groan and hum, whine like cables ready to snap, creak and crack, or go “piu” like laser guns in sci-fi sound effects.

“I love to hear the eerie sound of lake ice formation on those really cold mornings in early winter,” said Pete Boulay from the Minnesota Department of Natural Resources’ State Climatology Office.

The best chance to hear lakes sing is in the evenings, or any time there is a temperature swing.

Freezing water expands and makes noise. If you’ve ever had a can of pop explode in a freezer, you’ve already had this lesson.

Ice starts forming along shores and bays where water tends to be shallower and sheltered. It spreads toward deeper waters as lakes get cold enough to freeze on top. This ice sheet can act like the cover of a drum, amplifying the vibrations and sounds that come from below as ice shifts, shrinks and expands with the ups and downs of winter temperatures, according to the University of Minnesota Sea Grant Program.

Natural springs, fish activity, and the weight of people and vehicles on ice also can cause ice to flex and shift, making more sounds. That doesn’t necessarily mean danger, but any trip on the ice requires caution.

As a general rule, ice must be at least 4 inches thick for walking and close to 2 feet thick for trucks and fish houses. The DNR compiles a list of ice-in lakes as winter progresses, but it isn’t always up to date, and even a thickly frozen lake is never 100% safe, Boulay said. Read more about safety and survival guidelines on the DNR website or stay ashore and listen for the lakes’ winter soundtrack.

Learn more about the science and sounds of ice at this link.