Letter: Causing ripples

Professor Robin G. C. Bathurst
Sunday 08 August 1993 23:02 BST
Comments

Your support helps us to tell the story

From reproductive rights to climate change to Big Tech, The Independent is on the ground when the story is developing. Whether it's investigating the financials of Elon Musk's pro-Trump PAC or producing our latest documentary, 'The A Word', which shines a light on the American women fighting for reproductive rights, we know how important it is to parse out the facts from the messaging.

At such a critical moment in US history, we need reporters on the ground. Your donation allows us to keep sending journalists to speak to both sides of the story.

The Independent is trusted by Americans across the entire political spectrum. And unlike many other quality news outlets, we choose not to lock Americans out of our reporting and analysis with paywalls. We believe quality journalism should be available to everyone, paid for by those who can afford it.

Your support makes all the difference.

Sir: Regarding the shifting sands at Mawgan Porth (Letters, 5 August), T. G. Mercer's acute observation is in agreement with the known behaviour of sand in moving water. What he sees, as he walks along the dry beach, is the response of the sand to the last downslope movement of the water before it drained away altogether. A rippled surface forms as sand reacts with relatively slowly moving water, say in calm weather. At higher water velocities, associated with greater volumes of water during storms, a rippled interface between sand and water is no longer the most stable form. Instead the water and sand react to give a plane surface. It follows, of course, that the steeper the slope of the beach, the less the chance of finding ripples.

Yours sincerely,

ROBIN G. C. BATHURST

Department of Earth Sciences

Liverpool University

6 August

Join our commenting forum

Join thought-provoking conversations, follow other Independent readers and see their replies

Comments

Thank you for registering

Please refresh the page or navigate to another page on the site to be automatically logged inPlease refresh your browser to be logged in