ERTH 20 Lecture Notes - Lecture 2: Paleomagnetism, Continental Crust, Basalt
7 May 2020
School
Department
Course
Professor
Document Summary
Provides protection from the solar wind and cosmic rays: made of high energy particles, protons and electrons. Magnetic field is blown by solar wind into a tear drop shaped magnetosphere. Oceanic crust: denser than continental crust, made of basalt, density = 3. 0g/cm^3, average thickness = 8 km. Study pieces of upper mantle erupted from volcanoes. Study of what minerals might exist at very high temperatures and pressures. Studying earth"s shape, gravity, and magnetic field and how our crust moves. Asthenosphere: lower, warmer, part of mantle. Lithosphere: crust and uppermost, cooler part of mantle, brittle, rigid. Vertical movement of the crust due to the buoyancy of the lithosphere floating on the plastic asthenosphere. Greater thickness of continental crust also float lower in the mantle. Ocean crust is thinner and denser than continental crust so floats lower in the mantle. As earth cooled water vapor condensed to form clouds and rainfall.
