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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.
A lack of deep snow cover often contributes to this phenomenon because snow insulates the ground from intensely cold air. They often happen at night, when the air is coldest.
Sources: University of Toronto Climate Lab; Vermont Geological Survey.
tspears@postmedia.com
twitter.com/TomSpears1
查看原文...
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.
A lack of deep snow cover often contributes to this phenomenon because snow insulates the ground from intensely cold air. They often happen at night, when the air is coldest.
Sources: University of Toronto Climate Lab; Vermont Geological Survey.
tspears@postmedia.com
twitter.com/TomSpears1
查看原文...
