The non-equilibrium landscape of the Sierra Nevada, California: Reply

Abstract

We thank H.F. Garner for calling attention to an important factor governing fluvial erosion: the role of variable stream discharge caused by climatic fluctuations. We agree that climatic variations affect erosion rates and stream morphology by altering stream discharge, altering bed state such as armoring of channel bottoms and changing sedimentary flux, and can vary local base levels during glacial/interglacial cycles. These processes have most likely played a role in changing river profile form and erosion rates to some degree at various times throughout the Cenozoic in the Sierra Nevada. However, Garner argues that climatically driven changes in erosion rate led to elevation change through isostatic adjustment without any need to call on tectonic forces to explain the modern elevation of the range. This is where we disagree