By Tom Spears, Ottawa Sun, December 29, 2017
Winter is upon us and the cold is here to last, with double-digit negative temperatures forecasted for the next week. Is there a bright side to any of this? Not really. But we offer the tiniest of silver linings! To accompany this cold snap, we’re running a short-term daily feature: Cold Facts.
Long spells of deep cold bring frost quakes, or cryoseisms. Here’s how they work:
Water saturates the ground and then deep cold makes it freeze. The water expands as it freezes, and pressure builds up until finally a section of frozen earth near the surface cracks suddenly. Sometimes people feel the vibration. Often there’s a loud boom.
http://ottawasun.com/news/local-news/cold-facts-frost-quake-a-boom-in-the-night/wcm/3c953247-6fcb-475e-8e09-864781b56a07