Dripping and Denudation: The Effects of Erosion on Lithospheric Instabilities

Erosional modifications of surface topography may affect underlying lithospheric instabilities. We develop a theoretical model of lithospheric instabilities to explore how these instabilities may be enhanced by erosion. We first calculate the characteristic instability timescale of a perturbation to the lithosphere-mantle interface and investigate the sensitivity of this timescale to lithospheric rheology. Building off basic models of each mechanism in the system we construct a nonlinear, finite perturbation lithospheric instability model. Initially we model the effects of a self-softening damage rheology on lithospheric instabilities. Ultimately, this model will be used to explore how erosion of overlying topography can alter the wavelength and magnitude of the perturbations to the lithosphere-mantle system, and how these alterations affect lithospheric instabilities.