India, Jan. 27 -- An intense Arctic cold blast sweeping across the United States has prompted extreme cold warnings in multiple regions, with forecasters cautioning that the rapid temperature drop could trigger a rare cold-weather phenomenon known as an "icequake."

Parts of the Midwest, including the Chicago area, are under warnings as wind chills plunge 30 degrees or more below zero and air temperatures struggle to rise above zero. Weather experts say it is the speed of the cooling, rather than just the cold itself, that is raising concern.

While icequakes are uncommon, similar cold snaps in the past have produced loud booming sounds and brief ground vibrations, occasionally alarming residents and prompting emergency calls, according t...