Detection of transience in eroding landscapes

摘要: Past variations in climate and tectonics have led to spatially temporally varying erosion rates across many landscapes. In this contribution I examine methods for detecting quantifying the nature timing of transience eroding At a single location, cosmogenic nuclides can detect instantaneous removal material or acceleration over millennial timescales using paired nuclides. Detection is possible only if one has significantly shorter half-life than other. Currently, practical way doing use situ carbon-14 (14C) alongside longer lived nuclide, such as beryllium-10 (10Be). Hillslope information complement be used lieu information: soil mantled landscapes, increased detected millennia after increase by comparing relief ridgetop curvature. This technique will work long final rate greater twice initial rate. On landscape scale, may based upon disequilibria channel profiles ridgetops, but sensitive transient forcing. Where forcing periodic, landscapes display differing behavior driven changes base level lowering versus efficiency either hillslope (e.g. change). Oscillations lead basin averaged that reflect term average despite strong spatial heterogeneity local rates. averaging reflected 10Be concentrations stream sediments. Changes sediment transport coefficients large fluctuations rates, which again are concentrations. The variability where both erodibility vary dominated coefficient. Copyright © 2016 John Wiley & Sons, Ltd.