The Dynamic PlanetNatural Processes or Natural Disasters?The earth is a dynamic planet with complex internal and external flows of energy that produce natural processes that are supposed to happen and have been for billions of years.Natural disasters occur when the earth’s natural processes concentrate energy and then release it, causing property damage and/or loss of life.Origin of the Solar SystemSolar EnergyThe Sun is the Power House for the entire Solar System. It is a fairly typical star that is not burning, but is fusing together Hydrogen to form Helium. In so doing, it releases energy in vast quantities.Earth’s Internal HeatThree Sources of the Earth’s Internal Energy (Heat)Gravitational collapseImpact EnergyRadioactive decayEnd Result…Early Earth is hot, hot, hot!!!Earth StructureThe earth today is the product of over 4.5 billion years of differentiation into layers of varying density.The 8 most abundant elements in the earth areiron (Fe),oxygen (O),silicon (Si),magnesium (Mg),sodium (Na),calcium (Ca),aluminum (Al) andpotassium (K),Earth Structure - Density Stratified LayersEarth’s CoreThe earth’s core is composed of two parts, the inner core and the outer core.The inner core is SOLID iron (Fe) and nickel (Ni) and the outer core is LIQUID Fe and Ni.MantleThe mantle extends from roughly 50-2900km below the earth’s surface and is primarily composed of Fe, Mg rich silicates minerals.CrustIs composed of two types:Oceanic Crust is 7-10 km thick primarily made of Fe and Mg rich silicate minerals. (MAFIC; low Si and O, high Fe and Mg)Continental Crust is 20-70km thick primarily made of Si and O rich minerals (FELSIC; high Si and O, low Fe and Mg)Crust vs. MantleThe mantle contains MORE Fe and Mg than the oceanic crust and the oceanic crust contains MORE Fe and Mg than the continental crust.Because Fe and Mg are DENSER elements, the mantle is denser than the oceanic crust and the oceanic crust is denser than the continental crust.Density=mass/volumeEarth Structure - Layers of Different StrengthsThe crust and the upper part of the mantle is called the LITHOSPHERE and it is RIGID, BRITTLE and behaves ELASTICALLY.The part of the mantle directly below the lithosphere is termed the ASTHENOSPHERE which behaves like a PLASTIC - a solid that flows.Plate Tectonic Theory~12 large plates~12 small platesPlate Velocity - up to ~17cm/yearTypes of Plate BoundariesConvergent BoundariesDivergent BoundariesTransform BoundariesMoving plates cause EQ’s and volcanoes!The Dynamic PlanetNatural Processes or Natural Disasters?• The earth is a dynamic planet with complex internal and externalflows of energy that produce natural processes that are supposed to happen and have been for billions of years.• Natural disasters occur when the earth’s natural processes concentrate energy and then release it, causing property damage and/or loss of life.Origin of the Solar SystemRotating cloud of dust and gas gathers due to gravitational forces.Rotating mass contracts and flattens with most of the mass in the center.The center contracts into a ball of hot gas and dust which ignites to form the sun.Accretion resulted in planet formation whereby the gases outside of the sun condensed into solid materials.Solar EnergyThe Sun is the Power House for the entire Solar System. It is a fairly typical star that is not burning, but is fusing together Hydrogen to formHelium. In so doing, it releases energy in vast quantities. Solar energy drives the hydrologic cycle.Uneven distribution of solar energy causes severe weatherEarth’s Internal Heat Three Sources of the Earth’s Internal Energy (Heat)• Gravitational collapse• Impact Energy• Radioactive decayEnd Result…Early Earth is hot, hot, hot!!!Density Differentiation of the Earth produces Earths’ internal structure –Crust, Mantle, CoreEarth StructureThe earth today is the product of over 4.5 billion years of differentiation into layers of varying density.The 8 most abundant elements in the earth are • iron (Fe), • oxygen (O), • silicon (Si), • magnesium (Mg), • sodium (Na), • calcium (Ca), • aluminum (Al) and • potassium (K),Earth Structure - Density Stratified LayersEarth’s CoreThe earth’s core is composed of two parts, the inner core and the outercore.The inner core is SOLID iron (Fe) and nickel (Ni) and the outer core is LIQUID Fe and Ni. MantleThe mantle extends from roughly 50-2900km below the earth’s surfaceand is primarily composed of Fe, Mg rich silicates minerals.CrustIs composed of two types:Oceanic Crust is 7-10 km thick primarily made of Fe and Mg rich silicate minerals. (MAFIC; low Si and O, high Fe and Mg)Continental Crust is 20-70km thick primarily made of Si and O rich minerals (FELSIC; high Si and O, low Fe and Mg)Crust vs. MantleThe mantle contains MORE Fe and Mg than the oceanic crust and the oceanic crust contains MORE Fe and Mg than the continental crust.Because Fe and Mg are DENSER elements, the mantle is denser than the oceanic crust and the oceanic crust is denser than the continental crust.Density=mass/volumeEarth Structure - Layers of Different StrengthsThe crust and the upper part of the mantle is called the LITHOSPHERE and it is RIGID, BRITTLE and behaves ELASTICALLY.The part of the mantle directly below the lithosphere is termed the ASTHENOSPHERE which behaves like a PLASTIC - a solid that flows. Plate Tectonic Theory~12 large plates~12 small platesMantle convection drives plate motion.Heat Sources -Original heat from formation of the Earthradioactive decay of U, Th, and K in the core and mantlePlate Velocity - up to ~17cm/yearTypes of Plate BoundariesConvergent BoundariesDivergent BoundariesTransform BoundariesMoving plates cause EQ’s and
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