Most models predict that rivers only transport sediment during conditions of high flow and, moreover, that only particles on the surface of the river bed move due to the force of the flowing water above. But using a custom laboratory apparatus, a new study by University of Pennsylvania researchers shows that, even when a river is calm, sediment on and beneath the river bed slowly creeps forward.
By Madeleine Stone @themadstone
Rivers drive the evolution of Earth’s surface by eroding and depositing sediment.
But for nearly a century, geologists have puzzled over why theoretical models, which use principles of physics to predict patterns of sediment transport in rivers, have rarely matched observations from nature.