They happen when extremely low temperatures sweep in after a recent rain, said meteorologist Ed Shimon. Water near the ground's surface quickly turns to ice, expanding and building pressure until it cracks and pops. CHAMPAIGN — A noisy intruder? Or maybe a huge icicle crashing down from your roof? No, those loud booming and cracking sounds you've been hearing are a frigid-weather phenomenon called frost quakes, or sometimes ice quakes. read more