eally, who knew? Neither John or I have ever heard of an ice quake. For me this is understandable but he is Mr. Nova.

Anyway yesterday morning he told me that at 11:15 after I had gone to sleep there was a loud sound like the front door slamming and the house shook. Yesterday morning I called our neighbor who we share a wall with to see if she was OK and she said it was probably an ice quake.

Google says...

An ice quake is caused by ice shifting on the lake. And is usually accompanied by loud cracking noises.
It happens more often at night when the temperature changes are stronger.
Apparently a lot of expansion and contraction happens out on the big ice sheets that cover Madison's lakes in winter. One of the most dramatic occurrences happened a little before noon on Jan.15, 1948, when seismographs measured a tremor at 3.8 on the Richter scale. The day after that tremor of 60 years ago, a group of geology students discovered "a four-foot overthrust in ice 1-1/2 feet thick.

I have generally been pretty oblivious to weather. That means I am rarely dressed correctly. But since moving here I am much more aware of the weather in general. And now I know about ice quakes.