Standing ripples
Introduction
The photograph on this page of Standing ripples by Bob Harvey as part of the Geograph project.
The Geograph project started in 2005 with the aim of publishing, organising and preserving representative images for every square kilometre of Great Britain, Ireland and the Isle of Man.
There are currently over 7.5m images from over 14,400 individuals and you can help contribute to the project by visiting https://www.geograph.org.uk
Standing ripples
Image: © Bob Harvey Taken: 26 Dec 2021
At certain flow rates we see laminar flow over the ridges and corrugations in the bottom of the channel. Here the steady rain of the last 24 hours has produced exactly enough flow to make this work. In fact, this is odder than it looks. There is a stage between laminar and turbulent flow which, were these moving images, we could demonstrate here. The standing ripples are actually moving up and down in a regular manner, not quite breaking into turbulence, but more disturbed than a pure laminar flow.
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Image Location
Latitude
52.770667
Longitude
-0.386826