Geology Club Seminar

The interactions between climate, tectonics, chemical and physical processes on Earth's surface drive landscape evolution. Characterizing these interactions is central to understanding past and future landscape change. In this talk, I present two stories that show how processes above and below Earth's surface shape landscapes. First, I investigate how orographic precipitation influences surface processes. Using the deglaciated landscape of the Washington Cascade Mountains as an example, I show that orographic precipitation increased landsliding in the western Cascades following deglaciation, driving faster postglacial erosion in wetter parts of the landscape. Second, I show how tectonics and topography may influence the distribution of bedrock fractures. Applying a model of three-dimensional topographic stresses to three sites with different tectonic regimes, I find a strong correspondence between modeled stress and observed seismic velocities. This suggests that topographic stresses influence near-surface bedrock fractures, which in turn should alter patterns of weathering, erodibility, and groundwater flow.