Portage Glacier outside of Anchorage also empties into a lake which was formed by melting ice and snow into the bowl created by the retreating glacier. Same for Mendenhall. I’ve seen both of those glaciers when you could actually see the terminus from very close up (I was born in Juneau). Portage has receded so far that you need a tour boat to get to even see it. The glaciers that empty into Glacier Bay are, of course, coastal in nature, so they are emptying into salt water.
Hate to burst your bubble so to speak. NZ glaciers are all fairly fast flowing and the time from snowfall to glacier melt is generally 30-70 years. Your little air bubbles hadn’t been frozen that long.
Maybe the picture was taken 13,000 years ago? 
I lived in SLC for years and “ICECUBES” do form in the middle. One year I saw 15’ rise above water lvl.with shear cliffs. Term “ICEBERG” specific “a large floating mass of ice, detached from a glacier and carried out to sea.”
90% underwater; what’d you expect?
Just to nitpick, you mean “froze over completely.” Lake Superior is very, very deep - it is extremely unlikely that it has ever frozen solid, at least not since the last Ice Age.
Yes, sorry. Even up near the NWT the lakes freeze, but only to a depth of about 3 or 4 feet. That’s as far as the cold can get into the water, even at -40.
Of course, there is permafrost, left over frozen bog down dozens to sometimes over a hundred feet. But that’s because it is insulated by the peat against thawing too.
I have heard some spectacular stories of the ice chunks in the spring thaw. In one place, a river runs into anothr at a 90-degree angle, and the cross-current can catch and tip the 4-foot thick floes on edge so they are sticking way up in the air.
Again, Superior may not always or often “freeze over completely”, but it gets pretty solid enough around the shore, for example that wildlife often treks across to Isle Royale.
Lake Michigan does, indeed, have icebergs. They form near shore, break off, and float away. Nothing on the scale of Antarctica, and since shipping is halted in the winter anyway, I doubt if they are a serious navigation hazard.
Fresh zombie icebergs!
Anyway, as crimsontiger noted most recently and other posters in this thread have also pointed out, Lake Michigan and the other Great Lakes do NOT have icebergs in the strict sense of the term, which is “a large floating mass of ice, detached from a glacier”.
An ice chunk formed by seasonal freezing of surface water is not technically an iceberg, although both of them fit the looser definition of “big-ass floating mass of ice”.
I’m all for the strict sense. Otherwise, every river that freezes then thaws in spring is chock-a-block with icebergs.
My grandparents have a vacation home on the Upper Penisula side of Lake Michigan. Sometime in the early 70’s the neighbor’s house – which was much closer to the shore – got taken out by wind-driven ice floes. The ice just kept piling up and getting rammed from behind from more ice, until it eventually took out the front half of the house.
So no, not icebergs in the traditional sense, but ice floes big enough to actually do damage, yes.
Actually, she escaped from Kentucky by jumping from floe to floe on the Ohio River.
A lake with icebergs that I’ve been to, and in, is here in Iceland.