how can a waterfall or runner river just freeze when it's moving?

Question

like when your house in the winter starts to get all those pointy shingles or whatever you call it on the edge of our roof. how can running water just freeze like that?

Answer 1

temperature is strong my friend

Answer 2

It doesn't. :)

Any time you have flowing water, there are some places that move faster than others... A river is a good example.

The water on the riverbank often moves very slowly, or not at all. That water is the first to freeze. When that water freezes, the edge of the body of water has essentially moved toward the center a little bit. As water rushes by this edge, most of the water will continue on, but some water will stick to the crevices and cracks on the surface of the ice. That water on the ice is then not moving, and it too freezes. The colder it is outside, the faster the stuck water freezes, the faster this process becomes.

The same is for icicles... A drop of water that's waiting to drip is, for a little while, not moving. The next drop of water will cover the frozen drop (leaving a little water on the surface). Even if the second drop does fall off the roof, it's left enough water behind to enlarge the icicle just a tiny bit. Do that a few thousand times, and you can get some big icicles.

Answer 3

It doesn't just happen in minutes, but takes hours and hours of freezing. First the spray freezes, next the shallow edges, gradually increasing until the edges from both sides meet. Once this happens it is just a matter of time before the entire waterfall or river freezes completely. In the case of rivers, it is the slow running ones that freeze the fastest. It takes much longer for fast flowing ones and this includes waterfalls to freeze up......