EESC1168 Lecture Notes - Lecture 7: San Andreas Fault, Plate Tectonics, Tibetan Plateau
Document Summary
Past lecture slides and readings are on canvas. Review sheet will be posted on friday. Volcanoes, earthquakes, and tsunamis all arise due to movement of the earth"s crust. Plate tectonics = deformation and movement within earth"s outer layers. Crust = low-density rock at earth"s surface. Lithosphere = rigid, outer layer of earth. Volcanoes and earthquakes at the boundaries between plates and at hot spots away from boundaries. Asthenosphere = soft, weaker layer below lithosphere. See it when it flows to the surface as magma. Transform fault = plates slide past each other. First, melted magma flows upward and cools new ocean floor is formed. Lithosphere moves away from the new material ( seafloor spreading") Lithosphere is pulled back into the asthenosphere and melted at subduction zones. Divergence zones: creation of new land and mid-ocean ridges. Plates pull apart, resulting in a spreading center. Ex: iceland - growing, lots of magma. Transform faults: plates push past each other.