* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Download Planet Earth - Manasquan Public Schools
Survey
Document related concepts
Paleontology wikipedia , lookup
Geomorphology wikipedia , lookup
Provenance (geology) wikipedia , lookup
Marine geology of the Cape Peninsula and False Bay wikipedia , lookup
History of geology wikipedia , lookup
Plate tectonics wikipedia , lookup
Composition of Mars wikipedia , lookup
Age of the Earth wikipedia , lookup
Algoman orogeny wikipedia , lookup
Large igneous province wikipedia , lookup
Geochemistry wikipedia , lookup
Transcript
EARTH’S INTERIOR AND PLATE TECTONICS 17.1 SURFACE OF THE EARTH EARTH’S INTERIOR Earth is made up of 4 main layers. Crust Mantle Outer Core Core CRUST The outermost and thinnest layer of Earth. Oceanic Crust – thinner more dense crust (4 to 7 km) Continental Crust – thicker less dense (20-40 km, 25 miles) MANTLE The layer of rock between the Earth’s crust and its core. Denser than the crust. 2900 km thick 80% Earth’s volume CORE The center of a planetary body. Outer Core- liquid metal Inner Core- solid metal EARTH’S INTERIOR As you travel inside the Earth, the temperature will increase. The higher temperatures are a result of radioactive isotopes found in the rocks and layers naturally decaying PLATE TECTONICS The theory made by Dr. Alfred Wegner that Earth’s surface is made up of large moving plates. Pangaea - super continent when continents were one. (200 million years ago) PLATE TECTONICS 1. 2. 3. 4. Evidence supporting the theory: location of animal remains the Earth’s appearance (continental drift) Magnetic alignment of oceanic rocks show older rocks moving away from oceanic ridges Geological formations 250 million years in the future MOVING PLATES Lithosphere- the thin outer shell of the Earth, consisting of the crust and the rigid upper mantle. (over 30 large pieces) These pieces are called the tectonic plates Move 1 to 16 cm per year HOW PLATES MOVE Asthenosphere- the zone of the mantle beneath the lithosphere that consists of slowly flowing solid rock. The lithosphere “floats” on top of the asthenosphere. HOW PLATES MOVE Convection heat currents from the Asthenosphere causes the lithosphere to move. ASTHENOSPHERE PLATE TECTONICS PLATE BOUNDARIES Three Types: Diverging Faults Converging Faults Transforms Faults DIVERGING BOUNDARIES When two plates move apart. Caused by the rising of hot molten rock called magma. Forms mid-ocean ridges, new oceanic crust (rift valley), and volcanoes CONVERGING BOUNDARIES (SUBDUCTION ZONES) Areas where the lithosphere is diving under each other. (subduction) Trenches form between two oceanic plates (Mariana Trench off of Asia) Volcanoes, and mountains form when an oceanic plate and continental plate meet. Huge continental mountains form when continental plates collide (Mt. Everest) CONVERGENCE OF THE NAZCA AND SOUTH AMERICAN CONTINENTAL PLATES IN PERU. TRANSFORM FAULTS When rocks vibrate horizontally past each other at faults. Faults a crack in the Earth created when rocks on either side of a break move. Cause earthquakes San Andrea Fault EARTHQUAKES AND VOLCANOES 17.2 EARTHQUAKES The movement of the Earth’s lithosphere (tectonic plates) along transform faults. Japan, California, and western coast of South America experience the most. WHAT CAUSES EARTHQUAKES? Pressure builds up between moving plates causing rocks to break This releases energy as seismic waves. These waves cause the Earth to shake. PARTS OF AN EARTHQUAKE Focus is the exact area along the lithosphere where the earthquake originates. Causing waves to travel in all directions. Epicenter is the area right above the focus on the Earth’s surface. Fault SEISMIC WAVES Measured as shock waves These seismic waves help scientist understand the interior of the Earth. 3 types SEISMIC WAVES 1. Primary Waves ( P-Waves) Originate at focus Longitudinal vibration st 1 wave to reach recording station SEISMIC WAVES 2. Secondary waves (S waves) Originate at focus Move slower Transverse vibrations SEISMIC WAVES 3. Surface Waves Are the last waves to register with seismographs. Only move across the Earth’s surface. Circular motion vibrations Cause the most destruction SEISMOLOGY The science of detecting and measuring earthquakes Seismographs instruments used to measure data from an earthquake. There is over 1000 stations around the world Modern Seismograph How it works See in action SEISMOLOGY Scientist use the difference in time between P and S waves to calculate the distance to the epicenter. They need information from at least three stations to pinpoint the focus and epicenter of an earthquake. THE RICHTER SCALE a scale that represents the relative magnitude of an earthquake. Does not predict damage it will cause 30 http://earthquake.usgs.gov/earthquakes/ http://www.cnn.com/2010/WORLD/americas/01/12/haiti.earthquake/index.html HAITI SAN FRANCISCO 1918 ALASKA 1964 INDONESIA 2004 http://news.bbc.co.uk/2/hi/asia-pacific/4136289.stm Indonesia Google Maps Earthquakes VOLCANOES Vent Any opening in Earth’s crust where magma reached Earth’s surface. (lava) Release molten rock, lava, ash, and poisonous gas. TYPES OF VOLCANOES 1. Shield volcano Largest volcanoes very fluid lava that flows great distances. Eruptions are usually mild. Gentle slopes. Shield Volcano TYPES OF VOLCANOES 2. Composite Lava is much thicker traps gases in the magma causes the eruptions to be very violent (most destructive) Steeper slopes (Mt. Fuji, Mt St. Helens) MT. VESUVIUS- POMPEI TYPES OF VOLCANOES 3. Cinder cones smallest and most abundant gases are trapped they erupt violently with lots of ash. TYPES OF VOLCANOES 4. Seamounts Underwater volcanoes Seamount erupting VIRTUAL VOLCANO virtual volcano review WHERE DO VOLCANOES OCCUR 75% occur in the Pacific Ocean (Ring of Fire) Along divergent and convergent plate boundaries MINERALS AND 17.3 ROCKS STRUCTURE AND ORIGINS OF ROCKS All rocks are made and composed of mixtures of different minerals. -Minerals: are natural, inorganic solid compounds with a definite chemical composition and internal structure. 3500 known minerals in Earth’s crust Rocks and minerals classified by texture, hardness, color, and density. FELDSPAR PYROXENE MICA OLIVINE/ “PERIDOT” DOLOMITE QUARTZ CLAY CALCITE THREE MAIN ROCK TYPES Igneous Sedimentary Metamorphic IGNEOUS ROCK Rock formed physically from cooled and hardened magma or lava. As a rock cools minerals crystallize and grow. Size of crystals depend on how long the rock cools TYPES OF IGNEOUS ROCKS 1. Extrusive igneous rock cools on surface of Earth. Small mineral crystals Basalt, Obsidian EXTRUSIVE IGNEOUS ROCK IGNEOUS ROCKS 2. Intrusive igneous rock Form by cooling below the Earth’s surface. Larger mineral crystals granite INTRUSIVE IGNEOUS ROCK SEDIMENTARY ROCKS Rock formed physically from the compressed or cemented deposits of weathered sediment. Recycled rocks Sometimes contain fossils FOSSILS SEDIMENTARY ROCKS They are named according to the size of the fragments they contain. SEDIMENTARY ROCK EXAMPLES Conglomerate Rock with pebble sized fragments SEDIMENTARY ROCK EXAMPLES Sandstone Rock with sand sized fragments SEDIMENTARY ROCK EXAMPLES Mudstone Rock with fine mud sized fragments SEDIMENTARY ROCK EXAMPLES Shale Rock with flaky mud sized fragments SEDIMENTARY ROCK EXAMPLES Limestone Rock with fossils of organisms that lived in water METAMORPHIC ROCKS Rock chemically formed from other rocks as a result of being under tremendous heat and pressure for a period of time. New minerals form as a result METAMORPHIC ROCK EXAMPLES Marble Formed from limestone under heat and pressure METAMORPHIC ROCK EXAMPLES Slate Formed from mudstone or shale under heat and pressure ROCK CYCLE- OLD ROCKS WILL FORM INTO NEW ROCKS P 580 HOW OLD ARE ROCKS? Principle of Superposition Oldest will be on the bottom, and the newest on top. Useful with sedimentary rock and dating fossils Only gives a relative estimate age PRINCIPLE OF SUPERPOSITION HOW OLD ARE ROCKS? Radioactive Dating most minerals contain material with radioactive isotopes. Scientists measure the amount of radioactive material left in rock sample and compare to the rate at which the materials decay. Gives a more exact age of the rocks. RADIOACTIVE HALF LIFE DATING RADIOACTIVE DATING WEATHERING AND 17.4 EROSION WEATHERING Two Types: Physical Chemical PHYSICAL WEATHERING Process in which rocks are broken down into smaller pieces without altering the rock’s composition. Ice and plants are two types of physical weathering PHYSICAL WEATHERING When water seeps into rocks and then expands as it freezes, breaking the rock. Roots of plants can grow in between the wedges, and break the rocks. CHEMICAL WEATHERING Breaking down of rock by changing its chemical composition. (chemical reaction) EXAMPLE #1 Badlands (SD) are the result of chemical weathering Iron reacting with oxygen (oxidation) breaking down rock leaving new red hematite (Fe2O3) minerals on the surface. EXAMPLE #2 When CO2 dissolves in water, Carbonic acid is released This acid then breaks down the calcite forming underground caverns made of CaCO3. EXAMPLE #3 Acid rain Precipitation that has an unusually high concentration of acid in it. Formed as a result of excess burning of fossil fuels. Acid rain is strong enough to chemically break down rock leaving behind the remains of rocks. EROSION The physical process by which rock and the products of weathering are removed. Weathered material may be removed by running water, wind, ice, or gravity. This has shaped our planet WATER EROSION GLACIER EROSION BEACH EROSION WIND EROSION DEPOSITION Physical process of relocating sediment by laying eroded material in a different space.