Human Energy Use - Geophysics, Ocenography, & Energy● Japanese nuclear power plant explosion - put dent in economy● Earth is made up of layers: ○ Solid iron core in center○ Molten iron in outer core○ Mantle = less dense, elastic rock■ Aesthenosphere: very soft or melted rock■ Area of geothermal energy● Plate tectonics = movement of lithospheric plates○ Heat from Earth’s inner layers drives convection currents○ Pushing the mantle’s soft rock up (as it warms) and down (as it cools) like a conveyor belt○ The lithosphere is dragged along with the mantle○ Continents have combined, separated, and recombined over millions of years● Pangaea = all landmasses were joined into 1 supercontinent 225 million years ago● Earth has 15 major tectonic plates○ LA is on San Andreas Fault● Earth’s crust is created and destroyed● Types of Boundaries:○ Divergent plate boundaries■ Magma rises to surface, pushes plates apart, creates new crust, has volcanoes and hydrothermal vents○ Transform plate boundaries■ Two plates slide past each other, slipping/grinding, friciton spawns earthquakes along strike-slip faults○ Convergent plate boundaries■ Plates collide■ Subduction = oceanic plate slides under continental crust creating trenches (Cascades, Andes Mountains)■ Continental collision = two plates of continental crust collide (Himalaya, Appalachian, Rocky Mountains)● Plate tectonic build mountains○ Topography created by tectonics shape climate, affecting biomes.● Rock cycle○ Heating, melting, cooling, breaking, reassembling of rocks & minerals○ Rock = any solid aggregation of minerals○ Mineral = any element or inorganic compound■ Has crystal structure, specific chemical composition, and distinct physical properties● California is prone to earthquakes, and landslides● “Ring of Fire” is the ring of volcanoes around the Pacific Ocean.○ Q: What is the evidence of the plate movement/volcanic hot spots?○ A: older islands are submerged, present-day Hawaiian islands are younger● Alternative energy sources:○ Reasons for seeking alternatives○ Nuclear, hydroelectric, & biomass energy○ Usually exert less environmental impact○ Social debate over nuclear power● Keeling Curve○ Chip Keeling - Sullivan’s professor○ Keeling designed way to measure carbon dioxide● Fossil Fuels○ Electric cars still used energy from fossil fuels.○ Need to shift resources to be less easily depleted and environmentally gentler○ World Energy Production: Oil 34%, Coal 27%, Natural gas 20%, Biomass 10%○ Sweden’s government promotes hydroelectric, biomass, wind power; uses nuclear power instead of fossil fuels.○ The US relies more on fossil fuels and nuclear power than most other countries● Conventional alternatives● Nuclear Energy○ Nuclear energy - energy that holds together protons and neutrons within nucleus of an atom○ Nuclear fission - splitting apart of atomic nuclei, reaction drives release of nuclearenergy in power plants ○ Chain reaction keeps a constant output of energy○ Nuclear reactors - facilities within nuclear power plants■○ Nuclear fuel cycle - process that begins when uranium is mined○ Radioisotopes - emit subatomic particles and high-energy radiation as they decay into lighter radioisotopes - they become stable isotopes○ Uranium-235 decays into lead-207○ There exists a sophisticated system of building Nuclear reactors.■ Put into pool of water to slow that process down.■ Heat comes out of it, that boils water.■ Typical light water reactor■*no need to study Breeder Reactors● Drawbacks of nuclear power:○ Nuclear waste is radioactive○ If accident or sabotage occurs, consequence can be catastrohpic■ 1979 Island in Pennsylvania - meltdown from coolant water draingin from reactor, temperature rising, and melting metal surrounding fuel rods, releasing radiation.■ 1986 Cherynobyl contaminated 19 miles■ Fukushima Daiichi - tidal wave wiped out electric systems, 3 plants blew up.○ US plants now running out of room - waste is stored in thick barrels of steel, lead,concrete.○ Obama doesn’t