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Transcript
1 Bellringer #15 Read “Bats and Bridges” page 61 Answer the two What do you think? Questions in your journal. 2 Mysterious Fungus Ravages North American Bat Populations 3 Turbines Threaten Endangered Bats 4 Homework Define all of the vocab for Chapter 3. A list of the words can be found on page 86 Vocab is Due tomorrow! 5 6 Bellrigner # 16 What is the Geosphere? Where is most of the Geosphere located? 7 Chapter 3 The Dynamic Earth Objectives Describe the composition and structure of the Earth. Describe the Earth’s tectonic plates. Explain the main cause of earthquakes and their effects. Identify the relationship between volcanic eruptions and climate change. Describe how wind and water alter the Earth’s surface. 8 The Earth as a System The Earth consists of rock, air, water and living things that all interact with each other. Scientists divided this system into four parts: 1. The Geosphere (rock) 2. The Atmosphere (air) 3. The Hydrosphere (water) 4. The Biosphere (living things) 9 The Earth as a Integrated System 10 The Earth as a System geosphere is the mostly solid, rocky part of the Earth that extends from the center of the core to the surface of the crust atmosphere is the mixture of gases that makes up the air we breathe. * Nearly all of these gases are found in the first 30 km above the Earth’s surface. 11 The Earth as a System hydrosphere makes up all of the water on or near the Earth’s surface. a. Much of this water is in the oceans, which cover nearly three-quarters of the globe. b. water is also found in the atmosphere, on land, and in the soil. 12 The Earth as a System biosphere is the part of the Earth where life exists. a. extends from about 9 km above the Earth’s surface down to the bottom of the ocean. b. The biosphere is therefore made up of parts of the geosphere, the atmosphere, and the hydrosphere. 13 Discovering Earth’s Interior Studying the Earth’s interior is not easy. The deepest well that has been drilled into Earth’s interior is only about 12 km deep. An alternative method must be used to study the interior of the Earth. 14 Earth’s Interior Scientists use seismic waves to learn about Earth’s interior. Seismic waves are the same waves that travel through Earth’s interior during an earthquake. A seismic wave is altered by the nature of the material through which it travels. 15 Earth’s Interior Seismologists measure changes in the speed and direction of seismic waves that penetrate the interior of the planet. With this technique seismologists have learned that the Earth is made up of different layers and have inferred what substances make up each layer. 16 Earth’s Interior 17 Scientists divide the Earth into different layers based on : Composition- what it is made of Physical Properties- any aspect of an object or substance that can be measured or perceived without changing its identity 18 Composition of the Earth Earth is divided the into three major layers: 1. crust 2. mantle 3. core 19 crust -the thin and solid outermost layer of the Earth above the mantle. makes up less than 1 percent of the planet’s mass. Is composed almost entirely of light elements. The crust is the Earh’s thinest layer. 20 Composition of the Earth Mantle layer of rock between the Earth’s crust and core. The mantle makes up 64 percent of the mass of the Earth. • Made of rocks of medium density. Core the central part of the Earth below the mantle, and is composed of the densest elements. • Innermost layer 21 The Structure of the Earth The Earth can be divided into five layers: Lithosphere 2. Asthenosphere 3. Mesosphere 4. Outer Core 5. Inner Core 1. 22 Layers of the Earth 1. lithosphere the solid, outer layer of the Earth that consists of the crust and the rigid upper part of the mantle. • It is a cool, rigid layer that is divided into huge pieces called tectonic plates. 23 Layers of the Earth 2. asthenosphere the solid, plastic layer of the mantle beneath the lithosphere. a. It is made of mantle rock that flows slowly, which allows tectonic plates to move on top of it. 3. Mesosphere - Beneath the asthenosphere is the lower part of the mantle. 24 Layers of the Earth 4. Outer core is a dense liquid layer. 5. Inner core a dense, solid inner core, made up mostly of iron and nickel. • Although the temperature of the inner core is estimated to be between 4,000°C to 5,000°C, it is solid because it is under enormous pressure. 25 Five layers of Earth 26 Opening Activity Work with the people at your table Try to fit all of the cut out pieces together to form one large landmass. 27 Plate Tectonics Tectonic plates - are blocks of lithosphere that consist of the crust and the rigid, outermost part of the mantle and glide across the underlying asthenosphere. a. The continents are located on tectonic plates and move around with them. 28 The major tectonic plates include: Figure 4 pg. 66 1. The Pacific plate 2. North America plate 3. South America plate 4. Africa plate 5. Eurasian plate 6. Antarctic plates 7. Nazca Plate 8. Indian plate 9. Australian plate 29 Tectonic Plates 30 Alfred Wegener a German meteorologist developed the theory of continenetal drift. Relying on evidence from various scientific fields, Wegener proposed that all the continents were once joined into one landmass, which he named Pangea. Like many scientific theories, contintental drift was scored as its inception. Wegener’s ideas were not given full credence until decades later when oceanographic research found evidence for the 31 process of seafloor spreading. Plate Tectonics Tectonic plates may: Separate (divergent boundaries) Collide (convergent boundaries) Slip past 32 Seafloor Spreading Process in which new seafloor forms as molten rock from Earth's interior rises toward the surface, pushing the existing seafloor out of its way 33 Subduction Tectonic process that involves one plate being forced down into the mantle at an oceanic trench, where it eventually undergoes partial melting. 34 Transform Boundaries Horizontal plate movement in which one plate slides past another This movement creates faults 35 Plate Tectonics • Enormous forces are generated with these actions causing mountains to form, earthquakes to shake the crust, and volcanoes to erupt along the plate boundaries. 36 Plate Tectonics • • Where plates collide, the crust becomes thicker and eventually forms mountain ranges, such as the Himalaya Mountains. Look at Figure 5 pg.67 37 Earthquakes • A fault is a break in the Earth’s crust along which blocks of the crust slide relative to one another. • When rocks that are under stress suddenly break along a fault, a series of ground vibrations, known as earthquakes, is set off. 38 Earthquakes Earthquakes are occurring all of the time, but many are so small that we can not feel them. Other earthquakes are enormous movements of the Earth’s crust and cause widespread damage. 39 Earthquake Devastation in Kashmir Flattened by the massive earthquake that struck South Asia on Saturday, October 8, 2005, portions of the village of Balakot slide down a hillside and block the main road below. 40 41 Earthquakes The Richter scale is used to quantify the amount of energy released by an earthquake. The measure of the energy released by an earthquake is called magnitude. The smallest magnitude that can be felt is 2.0, and the largest magnitude ever recorded is 9.5. Magnitudes greater than 7.0 cause widespread damage. 42 Earthquakes The majority of earthquakes take place at or near tectonic plate boundaries because of the enormous stresses that are generated when tectonic plates separate, collide or slip past each other. 43 Where do Earthquakes Occur? 44 The 1964 Good Friday Earthquake On March 27, 1964 the world’s second largest earthquake ever instrumentally recorded shook Southcentral Alaska for up to 5 minutes, an eternity for someone on the ground. At 9.2 on the Richter scale it released a million times more energy than a 5.2 earthquake, which occurs several times a year in this region. 45 Bellringer # 17 How can volcanoes be harmful to our environment? How can volcanoes be helpful to our environment? 46 Volcanoes volcano is a mountain built from magma, or melted rock, that rises from the Earth’s interior to the surface, and can occur on land or in the sea. • Volcanoes are often located near tectonic plate boundaries where plates are either colliding or separating from one another. 47 Volcanoes Volcanoes may occur on land or under the sea, where they may break the ocean surface as islands. Figure 7 shoes, the majority of the wolrd’s active volcanoes on land are located along tectonic plate boundaries that surround the Pacific Ocean. 48 Volcanoes: The Ring of Fire 49 Global Effects of Volcanic Eruptions Major volcanic eruptions can change Earth’s climate for several years. Fig 8 pg 69 In large eruptions, clouds of volcanic ash and sulfur rich gases may reach the upper atmosphere, and spread across the planet reducing the amount of sunlight that reaches the Earth’s surface. The reduction in sunlight can cause a drop in the average global surface temperature. 50 Effects of Erosion The Earth’s surface is continually battered by wind and scoured by running water, which moves rocks around and changes their appearance. Erosion the process in which the materials of the Earth’s surface are loosened, dissolved, or worn away and transported form one place to another by a natural agent, such as wind, water, ice or gravity. Ex. Wind erosion and Water erosion 51 Homework Complete the Section 1 Review questions # 1, 2, 3 and 4 on page 70 Due Tomorrow. 52 53 Bellringer # 18 Name the 3 compositional layers of the Earth and the 5 physical layers of the Earth. 54 Bellringer #20 Why do planes fly so high, often 10km off the ground? 55 Objectives Section Two Atmosphere Describe the composition of the Earth’s atmosphere. Describe the layers of the Earth’s atmosphere. Explain the greenhouse effect. 56 The Atmosphere Atmosphere a mixture of gases that surrounds a planet, such as Earth. a. Nitrogen, oxygen, carbon dioxide, and other gases are all parts of this mixture. b. Gases can be added to and removed from. (which constantly happens) c. The atmosphere also insulates Earth’s surface. d. This slows the rate at which the Earth’s surface loses heat and keeps Earth temperature at which living things can survive. 57 Composition of the Atmosphere In addition to nitrogen and oxygen, other gases such as argon, carbon dioxide, methane, and water vapor make up the rest of the atmosphere. Nitrogen makes up 78 percent of the Earth’s atmosphere, and enters the atmosphere when volcanoes erupt and when dead plants and animals decay. Oxygen is the second most abundant gas in the atmosphere and is primarily produced by plants. 58 Layers of the Atmosphere The atmosphere is divided into four layers based on temperature changes that occur at different distances above the Earth’s surface. • • • • The Troposphere The Stratosphere The Mesosphere The Thermosphere 59 Layers of the Atmosphere 60 The Troposphere - the lowest layer of the atmosphere in which temperature drops at a constant rate as altitude increases. a. part of the atmosphere where weather conditions exist. b. extends to 18 km above Earth’s surface. 61 The Stratosphere - lies immediately above the troposphere and extends from about 10 to 50 km above the Earth’s surface. a. Temperature rises as altitude increases because ozone in the stratosphere absorbs the sun’s ultraviolet (UV) energy and warms the air. 62 The Stratosphere Ozone is a gas molecule that is made up of three oxygen atoms. a. Almost all of the ozone in the atmosphere is concentrated in the stratosphere. b. Because ozone absorbs UV radiation, it reduces the amount of UV radiation that reaches the Earth. UV radiation that does reach Earth can damage living cells. 63 The Mesosphere - layer above the stratosphere is the mesosphere. a. extends to an altitude of about 80 km. b. the coldest layer of the atmosphere where temperatures have been measured as low as –93ºC. 64 The Thermosphere - located farthest from Earth’s surface is the thermosphere. a. Here, nitrogen and oxygen absorb solar radiation resulting in temperatures measuring above 2,000 ºC. b. The air in the thermosphere is so thin that air particles rarely collide, so little heat is transferred, and would therefore not feel hot to us. 65 The Thermosphere The absorption of X rays and gamma rays by nitrogen and oxygen causes atoms to become electrically charged. Electrically charged atoms are called ions, and the lower thermosphere is called the ionosphere. Ions can radiate energy as light, and these lights often glow in spectacular colors in the night skies near the Earth’s North and South Poles called the Northern Lights. 66 Northern Lights 67 The Greenhouse Effect greenhouse effect - the warming of the surface and lower atmosphere of Earth that occurs when carbon dioxide, water vapor, and other gases in the air absorb and reradiate infrared radiation. a. Without the greenhouse effect, the Earth would be too cold for life to exist. 68 The Greenhouse Effect 69 The Greenhouse Effect The gases in the atmosphere that trap and radiate heat are called greenhouse gases. The most abundant greenhouse gases are water vapor, carbon dioxide, methane, and nitrous oxide, although none exist in high concentrations. The quantities of carbon dioxide and methane in the atmosphere vary considerably as a result of natural and industrial processes. 70 71 72 Bellringer #21 Read “Hydrothermal Vents” on page 78 Answer the questions on page 79 in your journal. 73 Objectives Section Three – Hydrosphere & Biosphere Name the three major processes in the water cycle. Discuss the factors that confine life to the biosphere. Explain open and closed systems. 74 Hydrosphere - includes all of the water on or near the Earth’s surface. Examples: oceans, lakes, rivers, wetlands, polar ice caps, soil, rock layers beneath Earth’s surface, and clouds. 75 Water cycle - is the continuous movement of water from the ocean to the atmosphere to the land and back to the ocean. Evaporation - is the change of a substance from a liquid to a gas. Water continually evaporates from the Earth’s oceans, lakes, streams, and soil, but the majority evaporates from the oceans. 76 Condensation - is the change of state from a gas to a liquid. Water vapor forms water droplets on dust particles which then form clouds in which the droplets collide to create larger, heavier drops that then fall from the clouds as rain. Precipitation - any form of water that falls to the Earth’s surface from the clouds, and includes rain, snow, sleet, and hail. 77 Water cycle 78 The Biosphere Biosphere - the part of Earth where life exists, extending about 11 km into the ocean and about 9 km into the atmosphere. The materials that organisms require must be continually recycled. Gravity allows a planet to maintain an atmosphere and to cycle materials 79 The Biosphere The biosphere is located near Earth’s surface because most of the sunlight is available near the surface. Plants need sunlight to produce their food, and almost every other organism gets its food from plants and algae. Most of the algae float at the surface of the ocean and is known as phytoplankton. 80 Energy Flow in the Biosphere Closed systems are systems that cannot exchange matter or energy with its surroundings. Open systems are systems that can exchange both matter and energy with its surroundings. Earth is essentially a closed system with respect to matter, but an open system for energy as energy travels from plant to animal which is eaten by other animals. In the process, some energy is lost as heat to the environment. 81 Energy Flow in the Biosphere The energy used by organisms must be obtained in the biosphere and must be constantly supplied for life to continue. When an organism dies, its body is broken down and the nutrients in it become available for use by other organisms. This flow of energy allows life on Earth to continue to exist. 82 Global Navigation Imagine you are planning a voyage around the world. You can choose any route you wish, but you must sail with the currents. Map out your route showing the names of the currents Where you are going to start Where you are going to end 84 Bellringer #22 How can gases be added and taken away from our atmosphere? List three examples. 85