mxm wrote:

A friend and I were driving through the Southern tier of Western New
York the other evening a little before sunset.

Dave noticed that there were odd patches and streaks of calm, bright
water on the surface of two ponds that we passed.

The calm, bright kind of surface also seemed to be near the shore of
the pond at one end at least (I didn't get out of the car and take a
good look all around the pond).

We argued about what might cause the effect. Unfortunately, we didn't
take any pictures to help with the argument.

My theory is that there could be any number of sources of oil (from
the road; from decaying vegetation in or near the pond; from geese
swimming in the pond). From our vantage point, we didn't see
irridescence and many of the odd patches were long streaks or bands
rather than circular.

That certainly could be a reason, but more likely it's just localized wind
effects.

Of course, it could be ice... I don't know what Western NY is like right
now, or how high you'd have been, but for sure it can't be _too_ long since
the ice was off their ponds. If they had thick ice, and it was protected
from wind break-up, there might be a large (thin) ice floe that's just
drifted against the shore. It's a month or more since I had that here,
but then we're very exposed to onshore winds and breakup was very early
(and fast) this year.
--
derek