Bedrock channel adjustment to tectonic forcing: Implications for predicting river incision rates

Abstract

Research Article| February 01, 2007 Bedrock channel adjustment to tectonic forcing: Implications for predicting river incision rates Alexander C. Whittaker; Alexander C. Whittaker 1Grant Institute of Earth Science, School of GeoSciences, University of Edinburgh, West Mains Road, Edinburgh EH9 3JW, Scotland, UK Search for other works by this author on: GSW Google Scholar Patience A. Cowie; Patience A. Cowie 1Grant Institute of Earth Science, School of GeoSciences, University of Edinburgh, West Mains Road, Edinburgh EH9 3JW, Scotland, UK Search for other works by this author on: GSW Google Scholar Mikaël Attal; Mikaël Attal 1Grant Institute of Earth Science, School of GeoSciences, University of Edinburgh, West Mains Road, Edinburgh EH9 3JW, Scotland, UK Search for other works by this author on: GSW Google Scholar Gregory E. Tucker; Gregory E. Tucker 2Cooperative Institute for Research in Environmental Sciences (CIRES) and Department of Geological Sciences, University of Colorado, Boulder, Colorado 80309-0399, USA Search for other works by this author on: GSW Google Scholar Gerald P. Roberts Gerald P. Roberts 3Joint Research School for Geological and Geophysical Sciences, Birkbeck College, University of London, Gower Street, London WC1E 6BT, UK Search for other works by this author on: GSW Google Scholar Author and Article Information Alexander C. Whittaker 1Grant Institute of Earth Science, School of GeoSciences, University of Edinburgh, West Mains Road, Edinburgh EH9 3JW, Scotland, UK Patience A. Cowie 1Grant Institute of Earth Science, School of GeoSciences, University of Edinburgh, West Mains Road, Edinburgh EH9 3JW, Scotland, UK Mikaël Attal 1Grant Institute of Earth Science, School of GeoSciences, University of Edinburgh, West Mains Road, Edinburgh EH9 3JW, Scotland, UK Gregory E. Tucker 2Cooperative Institute for Research in Environmental Sciences (CIRES) and Department of Geological Sciences, University of Colorado, Boulder, Colorado 80309-0399, USA Gerald P. Roberts 3Joint Research School for Geological and Geophysical Sciences, Birkbeck College, University of London, Gower Street, London WC1E 6BT, UK Publisher: Geological Society of America Received: 27 Jul 2006 Revision Received: 14 Nov 2006 Accepted: 16 Nov 2006 First Online: 09 Mar 2017 Online ISSN: 1943-2682 Print ISSN: 0091-7613 Geological Society of America Geology (2007) 35 (2): 103–106. https://doi.org/10.1130/G23106A.1 Article history Received: 27 Jul 2006 Revision Received: 14 Nov 2006 Accepted: 16 Nov 2006 First Online: 09 Mar 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn Email Permissions Search Site Citation Alexander C. Whittaker, Patience A. Cowie, Mikaël Attal, Gregory E. Tucker, Gerald P. Roberts; Bedrock channel adjustment to tectonic forcing: Implications for predicting river incision rates. Geology 2007;; 35 (2): 103–106. doi: https://doi.org/10.1130/G23106A.1 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyGeology Search Advanced Search Abstract We present detailed data of channel morphology for a river undergoing a transient response to active normal faulting where excellent constraints exist on spatial and temporal variations in fault slip rates. We show that traditional hydraulic scaling laws break down in this situation, and that channel widths become decoupled from drainage area upstream of the fault. Unit stream powers are ∼4 times higher than those predicted by current scaling paradigms and imply that incision rates for rivers responding to active tectonics may be significantly higher than those heretofore modeled. The loss of hydraulic scaling cannot be explained by increasing channel roughness and is an intrinsic response to tectonic forcing. We show that channel aspect ratio is a strongly nonlinear function of local slope and demonstrate that fault-induced adjustment of channel geometries has reset hillslope gradients. The results give new insight into how rivers maintain their course in the face of tectonic uplift and illustrate the first-order control the fluvial system exerts on the locus and magnitude of sediment supply to basins. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.