ERS120H5 Lecture Notes - Lecture 2: Continental Crust, Oceanic Crust, Continental Drift
Document Summary
Lecture 2: describe the difference between continental and oceanic crust (approximate thickness and density) and between the lithosphere and asthenosphere (approximate thickness and rigidity). Relatively ductile (easily deformed: explain the basic tectonic model (thin, rigid lithosphere over weak asthenosphere, interacting plates). The lithosphere is broken up into plates and these plates "float on the asthenosphere. These plates then move around and interact with each other in different ways: define isostasy and describe how it explains why the oceans are below sea level and the continents are, for the most part, above sea level. Isostasy: the condition that exists when the buoyancy force pushing the lithosphere up equals the gravitational force pushing the lithosphere down. Plates float at an elevation depending on thickness and density. This definition is saying that the lithosphere floats on top of the asthenosphere due to equal force and density.
