Snopes just debunked some pictures going around that are purportedly of icebergs in the Lake Michigan.
Are icebergs possible in the Great Lakes (or in freshwater in general)? Have there been documented cases of such? If they ARE possible in freshwater, are they common in, say, Lake Baikal (or similar larger, polar(ish) bodies of freshwater)?
They come from glaciers. Find a glacier that’s flowing into a lake, and you can end up with an iceberg there. That pretty much rules out the great lakes, which don’t currently have glaciers anywhere near them.
Possibly in some other mountainous regions of the world?
Would an ice floe count as an iceberg? As in, during the spring thaw, there has to be tons of free ice floating around as it slowly melts.
Pix!
I have waded in that water with the icebergs, and it is fukken cold. I stuck my nose up against a melting iceberg (okay, a very small iceberg) to breathe the trapped air in it that hadn’t been breathed for the past thirty thousand years. It was fukken cold too.
Any lake with a glacier flowing into it will generally have icebergs in it at certain times of year, such as Mendenhall Lake at the terminus of Mendenhall Glacier in Alaska.
Lake Baikal does not have glaciers flowing into it, and hence lacks icebergs.
Part of the definition of “iceberg” involves its having come from a glacier, so the answer is no.
It’s unclear whether the OP was interested in such a strict definition. If we use the term “iceberg” more loosely to mean “large floating chunks of ice”, then yes, some pretty big slabs of floe ice can be found on the great lakes, but they’re rarely more than a few feet thick; this is in contrast to true icebergs, which - like their parent glaciers - can be hundreds of feet thick.
sheet ice on the lakes does break up. they can get pushed up on to each other along the shore and freeze into one mass.
Lakes that freeze over in the winter can have floating ice, but they don’t really have “icebergs”, they way you’re thinking of. The ice on a frozen-over lake tends to be of about the same thickness everywhere, and it tends to melt at pretty much the same rate at springtime. And so you can’t get a giant block of ice floating in the water, instead you get thin sheets of ice floating in the water, and those thin sheets tend to get crunched up pretty easily. Even in Alaska where ice in ponds can be three feet thick it doesn’t really form “icebergs” in spring, just layers of rotten ice.
Although this sort of thing might count, ice flowing down the Chena river in downtown Fairbanks: http://www.youtube.com/watch?v=KHYzAHiaR4o&feature=related. It’s not exactly icebergs, rather a mass of ice chunks. But this will last only for a few days, and it’s mostly pretty small chunks, after all none of it will be much thicker than 3 or 4 feet.
Some glaciers also end in meltwater lakes - the Briksdal Glacier here in Norway is the first one that springs to mind - and those will have at least smallish icebergs in them as the glacier calves and drops chunks of ice into the lake.
I went swimming in Lake Michigan with the Goldbergs. That’s sort of the same thing, isn’t it?
When was it, about 20 years ago or so, that a large number of people from the Detroit area went ice fishing on Lake Erie during a cold spell. The wind came up and blew a huge ice floe (about 2 miles across or more, IIRC) ofshore. The coastguard had to come and rescue the fishermen with helicopters, but their vehicles (some were really nice looking trucks) were doomed to float around until the ice gave way.
Also, Lake Superior used to freeze solid every winter. During the second Metis Rebellion in Saskatchean (1880’s) the Canadian regiments had to march 60 miles along the ice near Lake Nipigon(?) to get from the unfinished east part of the CPR to the west ed of the railroad. On the way home next fall, the rail was connected.
IIRC one character in Uncle Tom’s Cabin escaped to Canada by jumping from ice floe to ice floe across the river.
Georgian Bay also ices up still most winters.
So large chunks of relatively thick ice (1 foot? Up to 3 feet in the north?) floating around the lakes, especially at spring breakup, are fairly common. But as others point out, they are (flat) floes, not (big chunk) bergs.
Ice floats so as everyone knows, ice will form a thin layer on the surface. With sufficient cold long enough (-30C to -40C), this may form a 3 or 4 foot thick layer, but to get a chunk 20 or 100 feet on all sides, you need an ice source that supplies the bergs ready made in that size. Generally that means glaciers.
I was of the impression that Lake Superior has only completely frozen over twice in recorded history (last 150 to 200 years). The last time was in 1979 according to this site. Wikipedia, of course, disagrees, but I don’t trust them. Yes it gets a butt load of ice on it, but there is almost always some clear water out there in the middle.
Yeah, it’s uncommon for the deeper Great Lakes to ice over completely due to the fact that their average water temperature really doesn’t change much from midwinter to midsummer. The top few feet of surface water may warm up a bit, but the other 900-1200 feet under the surface stays a cool but unfrozen temperature circa 40 degrees. So a little wind and current causing an upwelling will undo a freeze pretty quick.
I’ve only seen Lake Michigan freeze over once, in 1979, and I’ve lived along it for over half a century.
Here’s a nice scientific site with info on Great Lakes icecover: http://www.glerl.noaa.gov/pubs/brochures/ice/icecover.html
I remember Lake Superior freezing over in 1994 when I lived in the U.P. Minnesota SeaGrant backs me up on that.
Couldn’t they have gone out and attached an outboard motor to that ice floe, and pushed it close to shore, where they could get the vehicles off it?
BTW. here’s a view of this month’s Lake Michigan shore ice, taken from my front yard.
This site will tell you everything you want to know about Great Lakes ice: http://www.glerl.noaa.gov/data/ice/atlas/
Actually Lake Mendenhall at the foot of Mendenhall glacier just north of Juneau Alaska has small icebergs in it. The lake is freshwater. Saw it myself last fall. I can’t figure out how to post attachments, otherwise I would show you a picture.
As a side note, when glaciers carved out the Great Lakes they surely left icebergs for a brief period as they receded, leaving the lakes behind.
Love to see pics of Mendenhall, I’ve rafted in it!
Go to bayimg.com and post a pic there, and post the URL here, like I did in my post above.
I’m kinda glad I didn’t live by Lake Michigan when the glaciers were still here…
It was over a mile wide and headed from Detroit to Buffalo thanks to wind power. I don’t think a few outboards would have much effect; Plus, the coastguard wanted everyone off the (freezing water due to winds. They probably would not have been happy with some goofs trying to make a few bucks on maratime salvage and possibly needing rescue themselves. I wonder if the trucks sank before they went over Niagara Falls… 
How well do they float?
