Ice pizzas on a Scottish river, what’s that all about?

A very interesting event happened that day Flatnoch RiverScotland: Ice discs look almost like pizzas, but what are they?

Ice pizzas on a river in Scotland, illustration

Have you ever watched the series Do pizzas float down the river? That more or less happened Flatnoch River, in southwest Scotland. These are ice discs with a diameter of 20 to 200 centimeters, and their appearance is truly strange. Passers-by and residents of Wigtown County and Machars Peninsula (areas crossing the river) could not be interested in such a sight, so social networks were immediately filled with such photos and videos. Riverside Pizzeria.

Beyond aesthetic appeal, How did such a phenomenon arise? Let’s start by first saying that the past few days in the United Kingdom have been particularly brutal with temperatures below 0. December 12 was also the coldest day since 2010 and the thermometer did not go beyond that. -17.3 degrees in Scotland, in Bremer. “Ice Pancakes”, as they are nicknamed outside of Italy because they resemble regular pancakes, but in a frozen version, are a rare occurrence for Scotland. Examples have mainly occurred in Canada, the US, Antarctica and the Baltic Sea, but it is extremely unusual for the UK to see something like this.

It usually occurs in very cold oceans and lakes, appearing as discs with a raised rim due to the accumulation of millimeter ice crystals known as “frazil” and slush. As the formed ice continues to be moved by waves, the process of accumulation and circulation of the fringes is induced. This creates the circular shape of the discs. The tidal motion of the oceans then creates a greater thickness at the edges by splashing water.

But Platnoch is a river, not a sea: how did these disks form? Typical foam on river banks freezes as it is swallowed up by small eddies with low temperatures. The result obtained are ice discs, which increase in diameter when other foam collides with them, which in turn freezes.