Avoid frozen death

December 24, 2007 1:44 PM

I grew up in the California Central Valley - so I know nothing about ice. Now I'm in the Midwest. My question is: How do I know when it's safe to walk on a frozen river or lake?

I would like my margin of error to be small enough that I avoid being sucked into an under-ice river and dying while I claw frantically at an unrelenting ceiling of ice.

Also - are the rules different for rivers and lakes?

posted by crapples to education (14 comments total)

Where I grew up in Canada, the police test the ice levels and let people know when it's safe to go on the ice. I don't know if this is standard.
posted by acoutu at 1:46 PM on December 24, 2007

Where I grew up in Minnesota, it was often published in the papers when it was safe to walk or drive out onto the ice.

I personally wouldn't walk on a frozen river. The eddies under the ice can change from day to day, so it's hard to know where the weak spots are.
posted by adiabat at 1:49 PM on December 24, 2007

If it were me, I wouldn't walk onto ice like that unless I saw other people out there first:P

I don't really see why you'd want or need to, anyway.
posted by DMan at 2:04 PM on December 24, 2007

Distant, foggy childhood memories are rising to the surface. In elementary school in Ontario, they used to teach you how to tell if the ice was safe. Let's see... You want white or bluish solid ice, not clear ice. Water on the surface is a bad sign. I think frozen bubbles are a bad sign. Other parts of the pond being less frozen is a bad sign.

Beyond that, you can google 'ice safety' and see a million websites.
posted by PercussivePaul at 2:04 PM on December 24, 2007

Clear ice is safer, actually, white ice is usually thawed and refrozen (possibly with snow) or slowly frozen. Clear ice is more solid. You need about 4" for a person, although I wouldn't trust just that if you've got no idea what you're doing. The ice will be thinner wherever there's current (rivers, some areas in lakes) and thicker where the water is still (ponds), but will also tend to be weaker near the shore (despite being thick).

I find that you can have just as much fun on ice where the water was really shallow to begin with and now that it's frozen there's no liquid water at all...half the fun is seeing which bits you'll fall through anyway.
posted by anaelith at 2:15 PM on December 24, 2007

When somebody heavier than you walks out there first.

In all seriousness, I always avoided walking out out frozen lakes unless I had been told by a good authority that it was safe, OR it had been cold enough for long enough that I was confident the whole thing was frozen solid.

The fire department somehow got the job in my childhood town of drilling a hole in the ice on the town pond and declaring it safe for ice skating. (I never envied the guy who had to go out there first with the auger to drill the hole.) If the body of water you're interested in is owned by the town, I'd ask and see if they provide such a service or report. In many places where ice fishing is popular, you can get ice-condition reports from fishing websites, or just by asking at a place where fishermen hang out. Since they'll have holes drilled for fishing, they'll know how thick it is. Although some guys will go out on 1-2" ice, I wouldn't go near anything that's less than 3-4". But I have a minor phobia of falling through.

As for rivers, I think that's a lot more iffy. Some part of the river can be frozen solid while another part can be totally unsafe -- it all depends on how the water flows. Cover it all with snow, and it's essentially impossible to tell by inspection what's safe and what isn't. I would avoid rivers unless you really trust the person who's telling you that it's safe (and they go first!).
posted by Kadin2048 at 2:47 PM on December 24, 2007

On a lake, I'd say that six inches is safe enough to give you a good margin for most activities. The problem is that the ice gets thinner as you go farther out. The way we always used to test ice for skating on a lake was by walking out maybe 12-15 feet into the lake with a hatchet and chopping a hole there. As long as the lake was frozen all the way across, we were pretty sure that one person wasn't going to fall in only 4 yards from shore, and then based on how thick it was there we knew whether we could skate at all and if so, how far out we could go. Lakes and ponds never worried me much, as long as there's no open water visible. But I'd be very scared of any river that wasn't frozen all the way down.
posted by goingonit at 3:31 PM on December 24, 2007

If you're on one of the Great Lakes (like in Chicago or Duluth), never never never go out onto the water of the lake no matter how thick or clear or frozen it appears. The shoreline of the Great Lakes is incredibly hazardous in the winter; people drown every year on Lake Michigan because it looks really solid and it's not.
posted by nax at 4:31 PM on December 24, 2007

Rivers are trouble. I am from the frozen north and I never feel comfortable walking on a frozen river. They have thin spots all over the place and if you fall through, all the way through so that you submerge, you will be swept under the ice and be unable to get back up. What a way to go. Small lakes are a different story. They are safe at a few inches, four is pretty safe for even a team of sumo wrestlers. If you really want to be safe, carry some ice pick like things in you pocket so that if you go under you can pull yourself back onto the ice.
posted by caddis at 6:50 PM on December 24, 2007

As a general rule, most rivers are very unsafe for the simple reason that if you go under, you will be pulled away from the hole.

Find out what local paper carries ice thickness data, and follow their lead. Most lakes are checked by local law enforcement (we have a marine division that does it) and thicknesses are published in the paper. Less than 4" is totally unsafe. More than 4" is probably okay depending on how busy the lake is and on how warm the weather is.

Avoid dark ice unless it has been very cold for a long time. Freezing and refreezing mean that ice can be weaker, but it also means it's usually thicker.

Avoid water on the surface. Avoid bubbles. A little slush on the surface of a lake does not mean it's unsafe, the sun can cause this, but walking and seeing water come up as you walk - that's unsafe. If you walk and the ice feels bouncy, that's unsafe. Walk back the way you came.

Avoid walking on ice when the weather has been warming and the snow is thick on the ice. The snow acts as a blanket and can thin the ice, and you won't know it until you hear the cracking.

If you are on ice and hear cracking, pay attention. Creaking is probably okay, popping and "CRACK" sounds are very bad news. Walk, carefully, back to the shallows if you hear many warning signs.

Ice shanties or cars generally mean the ice is safe near them. If there is a clear line where cars or shanties don't go, then you don't go there either.

If ice is breaking under you, walk back, carefully (no stomping) the way you came but don't step in your footsteps - stay near them but on in them. If you do go through, STAY CALM if you can. You're going to be very cold and very wet. If you panic, you will break the ice around you and make the hole bigger, without getting you out. You don't have a lot of time before your muscles begin to stiffen, so climb out by trying to be as "flat" as you can - you want to slide up onto the ice on your belly, not try to climb up on a ledge. Once you slide up, belly-crawl away from the hole - keep your weight distributed (like a seal does) to ease the strain on the ice under you.

(from the "been there, done that as a dumb teenager" files)
posted by disclaimer at 9:24 PM on December 24, 2007 [4 favorites]

I always just waited until I saw snowmobiles out riding all over the ice.

As said above, be very careful if there is a lot of snow on top. In Wisconsin, the lakes are quite safe outside the Superior snow-belt. Inside the belt, very questionable. Mind, this is in a location where there is a county road across ice on Lake Superior (which, while it causes the snow belt, the belt is away from the lake), but other lakes, away from Superior, are not safe, due to insulation from the snow.

Once you find the safe place, I strongly suggest going out on a very clear night, to get away from the lights. The stars are truly awesome!
posted by Goofyy at 8:19 AM on December 25, 2007

i love walking on frozen lakes, rivers and all kinds of swamps. it's my favorite time of year to hike. you can see a lot more then any other time. i've grown up in the north, so i've been doing it for years. it's not something that i would recommend to a novice. see if you can find someone more familiar to show you the ropes.

the absolute first and last thing to remember is that it is NEVER safe. you have to be aware and prepared for the ice breaking at any time. listen, and watch carefully. have a strategy for getting back to the shore.

for lakes, if the lake doesn't freeze over completely, like the great lakes mentioned above, stay off. otherwise, watch the weather. you need about 4 days of below 32 weather to make it safe. that means the whole day under 32. walk closer to shore, especially at first when you are first going out. stay in an area that is somewhat shallow, so you have something to stand on if you break through. it's ok if the lake creaks and groans, but not because you are walking on it. if it's making noise with every footfall, get off. an occasional crack or thunk is ok, because ice expands as it's made, and will crack on it's own without losing strength.

rivers are much more dangerous. the real big ones tend not to freeze very well, so they are petty much off limits, except for some slow areas. river ice is much less predictable, and you can have an area of weakness right next to a strong spot. if you really want to hike on rivers, start by finding a couple of small creeks--once again, something shallow enough that you can stand on if you go through.
posted by lester at 12:35 PM on December 25, 2007

What everyone else said. Growing up in NH, we always checked with the police department to see if the ice was safe. Seeing other people walking on the ice doesn't mean a thing, since many people are stupid. Seeing cars or snowmobiles probably means it's safe for walking.

One thing that nobody's said - if you're on a lake, stay away from rocks. The ice doesn't freeze well around them (even if its fine everywhere else) and you can fall through. This happened to my little sister when she was about 5, and it was one of the scariest things I've ever seen. (We pulled her out and she was fine.)
posted by ilyanassa at 12:37 PM on December 25, 2007

Use a drill with a long bit to check the thickness. 4" is okay to walk on. I've had the pleasure of falling through (on a lake) and it really sucks. My advice would be to carry a long brach or hockey stick with you. In my case, it kept my head from going under as the stick was longer that the hole was wide. It could also be used to pull you out if you did fall in. Of course your clothing will pretty much turn into sheet metal in minutes, so don't be a mile from your car when you fall in, like I was.
posted by reidfleming at 10:21 AM on December 26, 2007