This doctoral dissertation research project will examine to what extent tectonic fractures modify the rates and styles of landscape evolution. These fractures are typically associated with the movement of tectonic plates, the faulting of rocks, and/or the eruption of volcanoes. Scientists have known since 1875 that these fractures influence how valleys deepen and widen over time, but what remains uncertain is how important the fractures are. What, for example, is the effect of a doubling in the bedrock fracture concentration on valley evolution? The doctoral student will examine two valleys, the Tuolumne Meadows of Yosemite National Park and the Mono Recesses of the Sierra National Forest. These valleys are similar in most respects, such as rock type, climate, and glacial history, but they are fundamentally different in their fracture concentration and style. The doctoral student will quantify the importance of tectonic fractures to landscape evolution in order to assess the effects of fracture concentration, orientation, and distribution for both of these distinct fracture styles.
This research project will contribute to enhanced understanding of how the surface of the Earth changes with time, and it will help refine numerical models to more realistically represent that evolution. The project will provide education and training opportunities for five undergraduate students who are working with the doctoral student. Information about the project and its results will be presented through public outreach in Yosemite National Park and the John Muir Wilderness. The project should yield practical benefits by assisting those engaged in modeling the evolution of specific landscapes over long periods of time, with special implications for geological engineering and hydrogeology. As a Doctoral Dissertation Research Improvement award, this award also will provide support to enable a promising student to establish a strong independent research career.
