Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Heat equation wikipedia , lookup
Copper in heat exchangers wikipedia , lookup
Building insulation materials wikipedia , lookup
Hyperthermia wikipedia , lookup
Solar air conditioning wikipedia , lookup
Cogeneration wikipedia , lookup
Thermal conduction wikipedia , lookup
Overview The Geosphere PSC 152 In this section: What is the structure of the Earth? What are the properties of each layer? How did these layers form? How do we learn about the interior? Geosphere layers Structure of the geosphere Crust Mantle Outer core Inner core Definitions from vocabulary Physical Properties For each layer, you should know… Location Composition Phase Relative thickness Relative temperature Crust What do you know about it? Thin, rigid surface layer Rocky, mostly silicates Coolest of all layers Oceanic verses Continental Mantle What do you know about it? Layer under crust mostly silicates, but denser than crust “plastic solid” Largest volume Warmer than crust Outer core What do you know about it? Liquid metallic Primarily iron and nickel Extremely hot Not as thick as mantle Inner core What do you know about it? Solid metallic Primarily iron and nickel Hottest region Extremely high pressure Formation How did this structure form? Two main factors: Gravity Heat Differentiation Gravity pulls into sphere Heat melts Densest material pulls to center See animation Density Mass/Volume Related to composition Earth on average = 5.5 g/cm3 Density of water = 1 g/cm3 Density of ordinary rocks = 3 g/cm3 Density of iron = 8 g/cm3 So earth must be a mixture rock and iron Scientific Method How do we know what we know about the structure of the earth? We do not have direct access to the interior of the geosphere … We must use indirect methods to gain information and test our hypothesis. Earthquake Waves Waves can travel through the earth Velocity depends on density and phase of the material it is going through Same method used for ultrasound on pregnant women You will be exploring this concept in the homework assignment Energy in the Geosphere Energy Source What is the dominate energy source in the geosphere? Thermal (heat) energy Affects of energy How does thermal energy cause change? Heat transfer Heat from interior is transferred toward surface Energy is transferred in the process Where did the heat energy come from? Kinetic energy from formation Nuclear energy from radioactive decay Heat transfer mechanisms 3 ways for heat to be transferred Conduction Convection Radiation For now, we only care about convection Convection Heat transfer through the motion of a hot material When a material heats, it expands The expanded material is less dense The material then rises, carrying heat animation Convection currents In a liquid or gas, the convection easily caused material to move and it forms circular currents In a solid, only a large heat gradient, will provide enough energy to cause very slow movement by convection In-Class activity Write 2-3 sentences for each of the following: What concept in today’s lecture: Did you find the hardest to understand Did you find the most interesting