Some strange booms have shaken residents in Fond du Lac County, Wisconsin.Read more: http://www.dailymail.co.uk/news/article-2538979/Wisconsin-cold-experiencing-ice-quakes.html#ixzz2qOwNJjkQ
The series of explosion-like sounds rattled residents from Waupun, Campbellsport and elsewhere Tuesday and sent Fond du Lac County sheriff's deputies out looking for a cause.
Geologists say the booms were likely a phenomenon commonly known as an ice quake.
They are the after-effects of the frost quakes - or cryoseism - which are more commonly found on glaciers in the polar regions.
It's caused by water that sinks into the soil and bedrock where it freezes and expands, causing an explosive popping sound that feels like a mild earthquake.
Most frost quakes occur after a heavy rainfall or snow fall when there is a large amount of moisture on the ground.
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