Loud outdoor booms, cracks and bangs are being reported from Minnesota to Illinois and Pennsylvania as ice quakes, also known as frost quakes or technically - cryoseisms, started popping up amid extremely cold temperatures.
"Basically, it’s so cold outside right now that you’ve got some moisture below the surface that’s starting to freeze," said meteorologist Ben Deubelbeiss of the National Weather Service.
"When the water freezes, it starts to expand and it’ll move the soil, subsoil, rocks and everything around it. That’ll create these little miniature quakes. The cracking of any frozen soil underground is what makes that popping sound that people hear," Deubelbeiss said.
Arctic air and gusty winds continue to impact a significant portion of the Upper Midwest into the Northeast, NWS forecasters warned.
Wind chill warnings and advisories are in effect through today. Heavy lake effect snows also continue downwind of the Great Lakes.
Several rounds of heavy lower elevation rains and mountain snows are expected across California through this weekend, with flooding possible near burn scars.
Featured image: NASA Aqua/MODIS