I. Why does the Earth have layers?II. Earth’s Internal Structure (you should know the relative thickness of each layer)GLG 112 1st Edition Lecture 2Outline of Last Lecture I. Course introductionOutline of Current Lecture I. Why does the Earth have layers? A. Early Earth was a very hot placeB. Early Earth was completely moltenC. The matter comprising Earth separated into layers based on densityII. Earth’s Internal Structure (you should know the relative thickness of each layer)A. Compositional Layers (defined by composition/density) (know relative densities)1. Core density ~ 10.7 g/cm32. Mantle density ~ 4.5 g/cm33. Crust (continental crust is thicker than oceanic crust)a. oceanic crust density ~ 2.9 g/cm3b. continental crust density ~ 2.8 g/cm3B. Rheological Layers (defined by Physical Properties) (know their physical properties)1. Inner Core (solid)2. Outer Core (liquid)3. Lower Mantle (solid)4. Asthenosphere (weak solid, soft solid)5. Lithosphere (solid)Current LectureThese notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute.Iron and nickel fell into the core at the beginning of time because of the higher density they have. That is just one example of how the earth separated into layers when it was hot and in liquid form. There are more compositional layers than rheological layers and they are overlapping of each other. Compositional layers are defined by composition or density. Therefore there are only three compositional layers. On the other hand rheological layers are defined by their physical properties so there are five. Did you notice that the solid lithosphere sits on a soft solid asthenosphere? That makes it easy for the asthenosphere to move and be shaped easily. This is not always a good thing. At least it moves
View Full Document