Unit 1 Notes Sun as Power Geology Electromagnetic Radiation We gain our knowledge by the study of light emitted from stars and other bodies. Ex. X-Rays, Cosmic Rays, Visible Light, Microwaves, Radio Waves (Classified by wavelength on the Electromagnetic Spectrum) Electromagnetic Spectrum Fusion vs. Fission Nuclear Fusion The way in which the Sun produces energy ---- nuclei combine Nuclear Fission When the nuclei split The Structure of the Earth Earth’s Insides In three main parts: The Crust The Mantle The Core Based on the composition of each part. The Crust Thin rocky outer layer Two parts: Oceanic Crust – younger rocks Continental Crust – older rocks The Mantle 82% of Earth’s volume is found here. Solid, rocky shell A change in the rock types The “Extra” Layers Lithosphere: A strong layer under the upper mantle. Asthenosphere: A soft layer, weak under the lithosphere. Earth’s “Extra” Layers Lower Mantle: A rigid layer, top of this layer rocks are solid bottom of the layer rocks are liquid. The Core Made up of two parts: Inner Core: Solid layer (pressure) Outer Core: Liquid layer The Cores Inner Core: The materials are pressed into a solid because of the pressure Outer Core: Liquid due to the extreme heat. Discovering the layers A scientist discovered that seismic waves happen under the surface in different layers. Earthquake waves can travel around the world in different layers of the Earth Things to know about Earthquakes 2 parts Focus: Point within the Earth where the Earthquake starts. Epicenter: On the surface above the epicenter. Where do Earthquakes occur? Faults How do they happen? Plate Tectonics http://www1.teachertube.com/viewVide o.php?title=Continental_drift&video_id= 98547&vpkey= http://www1.teachertube.com/viewVide o.php?title=Plate_Tectonics_Rap&vide o_id=82280 2 types of shocks Aftershock: Follows a major earthquake (could be smaller) Foreshock: Before an earthquake. Can happen years/days before an earthquake How do we measure waves? Seismograph 2 types of waves Surface Wave: Travel along the Earth’s surface Body Waves: P wave: push/pull wave through rocks (1st) S Wave: shake particles at right angles (2nd) P and S waves Finding the Center of the Earthquake Use three seismic stations to find the center Use a distance – time graph What we measure Intensity: Amount of shaking Magnitude: size/amount of energy released The scale Richter Scale: Based on the amplitude of the largest wave. The old way Moment of Magnitude: Amount of displacement from the fault The new way Types of Destruction 1.) Seismic Vibrations – damage to buildings/amount intensity 2.) Tsunamis 3.) Landslides 4.) Fires Predicating Earthquakes Short Range: Measures strain, not very successful Long Range: Helps with building codes, can’t really understand Seismic Graphs: Not a lot of activity along a fault line. Plate Tectonics Continental Drift Continental Drift Wegner – proposed the theory of continental drift. Continental Drift – The continents had once been joined to form a single supercontinent. Pangaea!!!! Evidence The continental puzzle Matching Fossils Rock Types and Structures Ancient Climates A New Theory Wegner’s theory was rejected. Plate Tectonics – based on earthquake knowledge. Plate Tectonics Plate Boundaries and Major Plates Earth’s Major Plates The lithosphere is divided into plates Earth’s Plates – move and continually change shape and size. Types of Plate Boundaries Divergent Boundaries – Two plates move apart. Convergent Boundaries – Two plates move together. Transform Fault – two plates grind together. Types of Faults Normal Fault Reverse Fault/Thrust Fault Strike-Slip Fault Actions at Plate Boundaries Divergent Boundaries Oceanic Ridge – Create an oceanic ridge – wide not narrow Rift Valleys – deep faulted structures Seafloor Spreading: Plate tectonics produce new oceanic lithosphere. 5 cm per year. Continental Rifts: East African rift valley Convergent Boundaries Subduction Zone – Oceanic crust is being pushed down into the mantle. Oceanic – Continental = Continental plate remains floating. Oceanic – Oceanic Continental – Continental Convergent Boundaries OceanicContinental Oceanic - Oceanic Continental – Continental Transform Fault Boundaries Plates grind past each other without destroying the lithosphere. Volcanoes Mt. Saint Helens Eruption May 18, 1980 Factors Affecting Eruptions Primary Factors: Magma composition Magma Temperature Amount of dissolved gases. Viscosity – the substances resistance to Volcanic Material Lava Flows Gases Pryoclastic Materials Types of Volcanoes Three main types: Shield Volcanoes Cinder Cones Composite Cones Inside A Volcano Other Volcanic Landforms Claderas – a large depression in a volcano Necks & Pipes – How magma gets through the volcano Lava Plateaus Soil and Weathering Mechanical vs. Chemical Weathering Occurs when physical forces break down rocks. Three process: 1.) Frost Wedging 2.) Unloading 3.) Biological Activity Transformation of a rock from one form to another Water: A major factor! Each type of material has a different rate of weathering. Mechanical Weathering Chemical Weathering Rate of Weathering Three factors are: 1.) Rock Characteristics: the physical way a rock looks 2.) Climate: Temperature and moisture 3.) Differential Weathering: Different parts of rock mass weather at different rates. Just a little soil information An important product of weathering Supports growth of plants Four major components: 1.) Mineral Matter: about 45% of the matter in soil 2.) Organic Matter: 5% (decayed things) 3.) Water: 25% water 4.) Air: 25% air The Soil Profile Soil varies in texture, composition, structure, and color at different levels. A Horizon – Topsoil B Horizon – Subsoil C Horizon – Soil Erosion Water helps to remove the topsoil that we need to grow plants and trees. Rates of Erosion: More plants, grass, and trees helps to hold the soil in place. Human activity that removes these things help to speed up erosion. Mass Movement What is it? The transfer of rock and soil down slope due to gravity. Caused by weathering and erosion. Triggers of Mass Movement Water Saturating Surfaces creating mudflows Oversteepened Slopes Water cuts under the bank of a river. Removal of Vegetation Taking away plants and roots Earthquakes Shake lose soil creating a landslide Types of Mass Movement Based on the kind of material, how it moves, the speed of the movement. Rockfall – When rocks fall from a steep slope. Slides – When land sides down suddenly. High mountain areas. More types Slumps – downward movement of a block of material in a curved surface. Creep – the slowest form of movement. Flows – mass amounts of movement 2 types: 1.) Mudflow – Moves quickly All about Rocks Random Rock Facts Rocks contain clues that tell us about the environment that they were formed in. Example: Rock with shells formed in a shallow ocean environment. Volcanic rock formed near a volcano Rocks A solid mass of mineral or mineral – like matter that occurs naturally as part of our planet. Three types: Igneous, Metamorphic, The Rock Cycle Interactions between Earth’s water, air, land, and living things can cause rocks to change from one type to another. Igneous Rocks Things to know: Magma: Under the Earth’s surface. Lava: Magma that reaches the Earth’s surface. When magma cools and hardens beneath the surface or a volcanic eruption. Igneous Rocks Coarse Grained vs. Fine Grained Glassy Texture vs. Porphyritic Granite Comp vs. Basaltic Comp Sedimentary Rocks Weathering – a process where rocks are chemically and physically broken down. Sediments are compacted and cemented together. Sedimentary Rocks Compaction and Cementation Clastic and Chemical Jellyfish fossil in sedimentary rocks Ripple Marks show where a river was. Metamorphic Rocks Bury sedimentary rocks deep within the Earth. Increase pressure and temperature. Change into Metamorphic Metamorphic Rocks Contact and Foliated and Regional Nonfoliated Energy to rock the Rock Cycle Process are: From Earth’s interior – heat (igneous and metamorphic) From Earth’s exterior – sun, weathering, movement or materials (sedimentary)