GGR201H1 Lecture Notes - Lecture 2: Plate Tectonics, Geologic Time Scale, Mantle Convection
Document Summary
Result from application of physical and chemical forces to materials and landforms at earth"s surface. Processes wear and carve away at land surface. Fluctuations in base level or the elevation to which systems are adjusting. Both magnitude and frequency of geomorphic agents are relevant. Ability to do geomorphic work varies with frequency of event and intensity of event. High frequency events tend to be low intensity. Need to balance frequency and magnitude so that event is both intense enough and frequent enough to play a meaningful role on the landscape. Gravitational forces between earth and water, ice, and sediments. Compared to buoyancy of solid object floating in liquid. When oceanic plate subducts under another, island arc (chain of steep, explosive volcanoes) When oceanic plate subducts under another, island arc (chain of steep, explosive volcanoes) forms. Accretionary wedge of sediment scraped off downgoing plate can form coastal mountain belt.
