Ice cracking

[Greywolf25]

New to ice fishing. In a 16’ ice castle in a lake with 17 inches of ice. Ice is cracking so much it sometimes shakes my house. Anything to worried about? 

[monstermoose78]

No it’s making ice 

[Wanderer]

Must’ve gotten woke up?!  Sometimes it’s loud enough you sick your head out to look around but it’s normal.

[BobT]

8 hours ago, Greywolf25 said:

New to ice fishing. In a 16’ ice castle in a lake with 17 inches of ice. Ice is cracking so much it sometimes shakes my house. Anything to worried about? 

Perfectly normal. Ice is a brittle solid but it is also extremely buoyant. It starts by freezing on the surface and then builds downward as more water freezes. When water freezes it expands its volume and this adds pressure due to both buoyancy and larger volume. That's why a plastic water bottle in the freezer will bulge after it's frozen. Since ice is very hard and brittle it doesn't bend easily so as the pressure from expansion and buoyancy increases, the ice eventually gives way and cracks. A lot of small cracking can actually be a good sound. It means the ice is getting thicker and it isn't building up for something major. This is similar to the earthquake risk on the west coast. Regular smaller quakes is better than none because the longer time between events the more likely the events are bigger and more dramatic.

 

In some rather rare cases ice can be quite dramatic in a couple ways and for this reason ice should never be considered 100% safe. We must always be alert and cautious on ice. One way is when pressure builds and the ice finally gives way it can buckle causing a pressure ridge. See attached photo below. My local lake Osakis has a reputation for producing one of these pressure ridges every year across the middle of the main lake body.  

 

In other situations the ice can crack and due to its buoyancy it will lift and separate rather than buckle. The photo below was one extreme incident.

 

Here's one I heard about. Back in the late 90's I was organizing an annual ice fishing trip up the LOTW for late February. One year about two weeks before our scheduled trip, I heard about one of the resort transport vehicles going through the ice. In late February the ice on LOTW is usually about 3 feet thick or more. When I asked about it I was told what happened was the ice had cracked open and separate about 6' wide. It refroze a thin layer over the top and then they got a couple inches of new snow. With everything white from the new snow, the new fissure in the ice was not noticed by the driver as they drove out in the morning and they drove over it and went down. 

 

Don't have to fear the ice but always remember to be alert, cautious, and use a little forethought. 

[smurfy]

Wow, what a great explaination!!! thanks for that post.

[gim]

This is what the DNR recommends at a minimum.  Its been unseasonably warm this winter.  Its gonna be 40 today (50 in western MN with rain coming) during which is supposed to be the coldest time of year.  At this rate half the state will be open water by March.

 

 

Edited January 13, 2021 by gimruis

[BobT]

Still making ice on Osakis. In the past week, it went from 12" to 16". It is the clearest, hardest ice I've seen in a long time. 

[BobT]

Conditions vary from place to place though. Yesterday I was on the north end of Sauk Lake, about 10 miles east of here, and only found 12" of ice.