Using Cosmogenic Nuclide Measurements In Sediments To Understand Background Rates Of Erosion And Sediment Transport

Abstract

Understanding the tempo of sediment generation and transport is fundamental to understanding Earth as a system. For land managers, knowing rates of landscape change is important as they consider human impact on landscapes in a long-term context. Numerous means have been employed to estimate basin-scale erosion rates (Saunders and Young, 1983); many of these methods, such as calculations based on river sediment and solute transport rates, are influenced by human impacts or are useful only over short (10 to 100 y) time scales (Trimble, 1977). Other techniques involve reconstruction of initial topography or definition of sediment volumes and source areas; however, these techniques are feasible only in particular environments and geologic settings, many of which are uncommon (Bishop, 1985). Sediment transport rates can also be estimated using tracers (e.g., Lekach and Schick, 1995) and sediment traps. The traditional means by which basin-scale erosion and sediment transport rates are estimated remain uncertain and thus are not widely applied.