Joel Johnson and Kelin Whipple have just had another interesting article on bedrock channel erosion published. Here they circumvent the usual problem of the unmanageable timescales of laboratory erosion experiments by employing a "bedrock" made of weak concrete. The principle aim of the study is to examine the role of sediment in bedrock erosion, both as a tool for erosion, and as a protective blanket on the channel bed. They found a linear increase of erosion rate with sediment flux, and a linear decrease of erosion rate with alluvial bed cover, while also highlighting the importance of local bed topography on bed cover. Important results from an elegant experimental set-up!
Here are some previous publications from the pair, an informed combination of careful laboratory and field studies.
Johnson J P and K X Whipple (2007). Feedbacks between erosion and sediment transport in experimental bedrock channels. Earth Surface Processes and Landforms, 32 (7), p. 1048-1062, DOI: 10.1002/esp.1471.
Johnson, J. P. L., K. X. Whipple, L. S. Sklar, and T. C. Hanks (2009), Transport slopes, sediment cover, and bedrock channel incision in the Henry Mountains, Utah. J. Geophys. Res., 114, F02014, doi:10.1029/2007JF000862.
Johnson, J. P. L., K. X. Whipple, and L. S. Sklar (2010), Contrasting bedrock incision rates from snowmelt and flash floods in the Henry Mountains, Utah. GSA Bulletin, 122 (9-10), p. 1600-1615.
Famous Landmarks on the Island of Skye
2 hours ago