Giant Bialy

March 06, 2023



Photographer: Roger Hopkins  
Summary Author: Roger Hopkins  

Our waterfall produces a full menu of foam goodies, including marshmallows, pancakes, donuts, bagels, and recently, a spectacular bialy. This foam, frequently misunderstood to be man-made pollution, is a natural phenomenon in our case. Decaying plant material is mixed in the turbulence of the stream, acting as a surfactant to reduce the surface tension of the water and allowing the formation of persistent small "soap" bubbles in the turbulence. We normally see these after a period of rain with more organic material leaching into the stream.

The waterfall has this nice gentle eddy at the base that forms these round shapes. The brown streaks are probably caused by tannin washed into the stream from decaying oak leaves and branches upstream. Click here to see a video of this foam forming. Photo taken on January 5, 2023.

Asbury, New York: 42.526283332981414, -76.48522451537521

Related Links:

Roger’s Website

More About Foam in Rivers