TY - JOUR
T1 - Expression of active tectonics in erosional landscapes
AU - Kirby, Eric
AU - Whipple, Kelin
N1 - Funding Information:
We thanks the editors of JSG, particularly Tim Horscroft, for both soliciting this review and for patiently seeing it through to completion. Marina Foster Bravo and Mike Zoldak assisted with Figs. 9 and 11 , and Scott Miller helped compile data for Fig. 3 . Both authors' research has been supported by the Tectonics, Continental Dynamics, and Geomorphology and Land-Use Dynamics programs at NSF. EK acknowledges support from the Alexander von Humboldt Foundation during the writing of this manuscript. Thoughtful reviews by Doug Burbank and Andy Moore helped improve the clarity of the manuscript.
PY - 2012/11
Y1 - 2012/11
N2 - Understanding the manner and degree to which topography in active mountain ranges reflects deformation of the Earth's surface remains a first order goal of tectonic geomorphology. A substantial body of research in the past decade demonstrates that incising channel systems play a central role in setting relationships among topographic relief, differential rock uplift rate, and climatically modulated erosional efficiency. This review provides an introduction to the analysis and interpretation of channel profiles in erosional mountain ranges. We show that existing data support theoretical expectations of positive, monotonic relationships between channel steepness index, a measure of channel gradient normalized for downstream increases in drainage area, and erosion rate at equilibrium, and that the transient response to perturbations away from equilibrium engenders specific spatial patterns in channel profiles that can be used to infer aspects of the forcing. These aspects of channel behavior lay the foundation for a series of case studies that we use to illustrate how focused, quantitative analysis of channel morphology can provide insight into the spatial and temporal dynamics of active deformation. Although the complexities of river response to climate, lithology, and uplift patterns mean that multiple interpretations of topographic data alone will always possible, we show that application of stream profile analysis can be a powerful reconnaissance tool with which to interrogate the rates and patterns of deformation in active mountain belts.
AB - Understanding the manner and degree to which topography in active mountain ranges reflects deformation of the Earth's surface remains a first order goal of tectonic geomorphology. A substantial body of research in the past decade demonstrates that incising channel systems play a central role in setting relationships among topographic relief, differential rock uplift rate, and climatically modulated erosional efficiency. This review provides an introduction to the analysis and interpretation of channel profiles in erosional mountain ranges. We show that existing data support theoretical expectations of positive, monotonic relationships between channel steepness index, a measure of channel gradient normalized for downstream increases in drainage area, and erosion rate at equilibrium, and that the transient response to perturbations away from equilibrium engenders specific spatial patterns in channel profiles that can be used to infer aspects of the forcing. These aspects of channel behavior lay the foundation for a series of case studies that we use to illustrate how focused, quantitative analysis of channel morphology can provide insight into the spatial and temporal dynamics of active deformation. Although the complexities of river response to climate, lithology, and uplift patterns mean that multiple interpretations of topographic data alone will always possible, we show that application of stream profile analysis can be a powerful reconnaissance tool with which to interrogate the rates and patterns of deformation in active mountain belts.
KW - Active tectonics
KW - Neotectonics
KW - River profiles
KW - Tectonic geomorphology
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U2 - 10.1016/j.jsg.2012.07.009
DO - 10.1016/j.jsg.2012.07.009
M3 - Review article
AN - SCOPUS:84867474013
SN - 0191-8141
VL - 44
SP - 54
EP - 75
JO - Journal of Structural Geology
JF - Journal of Structural Geology
ER -