I have always thought that they were. But on a recent trip to Scotland, very few of the lakes (lochs) are even a little bit round! Most are carved by glaciers and what not and are quite elongated. I guess round lakes come mostly from volcano calderas.
So are most lakes in the world round?
I’m going to make a guess that they aren’t. Lakes follow the topography, and there are more elongated features than round ones.
I have seen very few round lakes.
Lakes are the shape of the depression (usually but not always valley) they are located in. Many smaller lakes are more or less round, as quasi-circular depressions are not at all uncommon. But a lake from damming a river will occupy the area above the dam, which is generally the river valley. Scottish lochs occupy valleys between massifs, and are generally long and narrow in consequence. Note that none of the largest lakes are anything like circular, Lake Victoria and the Aral Sea coming closest, but the Caspian, Balkhash, Baikal, Ladoga, Onega, Superior, Michigan, Huron, Erie, Ontario, Okeechobee, and almost all the African Rift Valley lakes are far from circular.
Thanks all - that makes sense.
Here’s a round one (actually an old caldera) and one that’s sooo not round. (this one is technically a reservoir as it is a Valley Of The Dammed)
Why are you assuming that volcano calderas are round? They’re not.
There are also crescent-shaped oxbow lakes, which are formed when a meandering river cuts across a bend. The old river bed becomes a lake.
Kettlesare a particular type of very round shallow lake formed by drainage from a receding glacier. Often they’re unconnected to the nearby river systems and they become bogs.
So… there’s really all sorts of lakes with all sorts of shapes.
Why would you assume all lakes are round? A perfectly round lake is rare but some exist either formed by a volcanic crater or terrestrial impact craters.
I wouldn’t call it round, but then again I wouldn’t call it far from circular either 
IMO it’s one of the more circular lakes I know of.
Kettle Lakes are also round. Jamaica Pond in Boston is a good example. They’re caused by large ice blocks that “calve” off retreating glaciers, although I’ve never understood why they tend to be round:
True – I was simply rattling off a list of large lakes on the major continents, and included it without thinking. Okeechobee is probably the largest near-circular lake on Earth, depending on how close to perfectly circular you want to hold the definition.
Yes, lazybratsche mentioned them in post #8. Sorry, I didn’t mean for my post to be read as exclusive causes of round lakes.
Here’s a round lake I’ve always found cool: Manicouagan, an annular lake in Quebec.
Then there’s Lake Pontchartrain (actually an estuary), which is a little smaller in area but probably a bit larger in volume. (Both are quite shallow.)
Since I live close to the Great Lakes, all very not round, and am also close to the Finger Lakes, so named because they look like finger-shaped impressions in the ground (yes, caused by glaciers), I find the whole notion of round lakes improbable.
They’re so rare that a lake in New York north of Albany is actually called Round Lake. Google maps only lists one other, Round Lake in Illinois. If you look at that area, you see a thousand small lakes, none of which are round.
I would expect any area covers in glaciers from the last ice age to have virtually all irregularly-shaped lakes. Round lakes are very much the exception.
Have a look at a map of Minnesota, nicknamed “Land of 10,000 Lakes.” Very few of the lakes are even approximately round.
Because the block of ice is banged around until it reaches the shape that causes the least friction, whereupon it is deposited at the lowest point in the geography. Happens to quite a few rocks caught in glaciers, too.
If that’s the case, then nobody ever made it clear that the ice “got banged around”. I’ve always pictured the ice calving right off the end of the glacier, which would’ve resulted in an irregularly-shaped lake.
Well, the glacier doesn’t physically retreat either, it melts. Meltwater from a large enough glacier can easily cause a new river to form, so anything left there won’t remain for long.
