An observant viewer has spotted a special natural phenomenon at the weir in the Sterrenbos in Roden. Dozens of disks of ice float on the water’s surface. Pancake ice cream, says RTV Drenthe weather forecaster Grieta Spannenburg. “A lot of people ignore it.”
The pancake ice, or ground ice, only forms under special circumstances, Spannenburg explains. “It forms deeper and comes to the surface. They are water bubbles that rise. Water at zero degrees is lighter than water at five degrees. So if a water bubble is lighter than its surroundings, it rises. When it rises, it freezes completely. fast.”
The discs look a bit like solidified fat due to their cloudy color. “That’s because the water bubbles take stuff from the bottom with them. And they spin a bit, so they keep that shape,” says Spannenburg.
“Last night’s cold and wind also play a role. Then it freezes considerably on the surface, causing a bubble like this to freeze in one go.” The flowing water also makes it easier for the pancake ice cream to form.
Spannenburg saw it with his own eyes once before, on the Wadden Sea. “Those were larger disks. Many things have to coincide exactly. It is very difficult to anticipate.” And when it does occur, it is not always noticed, says Spannenburg. “The observant viewer sees this, but many people ignore it. A very beautiful observation.”