PPT-Chapter 5: Volcanoes 5.1 Volcanoes and Plate Tectonics

Volcanoes Volcano mountain that forms in Earths crust when molten material magma reaches the surface Remember magma is molten rock below ground lava is molten rock at the surface . Notes. Geology – . the study of the Earth and its processes. 2. The Earth’s. . Layers. Scientists study seismic (earthquake) waves and volcanic explosions to learn about the Earth’s interior.. Yellowstone Park is not only spectacular but also unique. It is the result of three volcanic eruptions, the likes of which have never been seen in all of recorded history. The first eruption occurred 2 million years, followed by two more eruptions 1 million years and 600,000 years ago. Below Yellowstone Park there is a hot spot that is generating basaltic magma. At the time of each of their three eruptions, the magma chamber began to produce large volumes of basaltic magma. Because of its low viscosity, the basaltic magma quickly rose to the bottom of the granitic continental crust. However, because the density of basaltic magma (density about 3) is slightly higher than that of granite (density about 2.9) it could not force its way through the granite to the surface. Instead, it began to pool beneath the granitic crust. The amount of heat trapped within the molten basaltic magma was enough to melt the minerals making up the overlaying and surrounding granite, forming a growing mass of granitic magma. Granitic magma is highly viscous and extremely gas-charged. Although it rose only very slowly, the granitic magma advanced upwards by melting even more of its own overlying granitic rock. At some point, radial fractures began to form around the rising mass of granitic magma. These fractures allowed steam eruptions to vent gas. Shortly after, with the overlying granitic rock severely weakened by the fractures, the highly gas-charged granitic magma erupted. The land to a distance of 200 miles in all directions was decimated. Pyroclastic flows, the most destructive eruptive features known, swept across the countryside. Ash fell across the country from the eruption site to the Atlantic Ocean. Ash polluted the world’s atmosphere, blocked the energy of the Sun, and plunged the Northern Hemisphere into a frozen wasteland for years. Can such an eruption occur in the Yellowstone region again? All the evidence suggests that the magma chamber below Yellowstone Park is current rising. According to the director of the Yellowstone Volcanic Observatory, it is not a question of whether or not another super-eruption CAN happen; it’s a question of WHEN it will happen!. Structure of the Earth. The Earth is made up of 3 main layers:. Core. Mantle. Crust. Inner core. Outer core. Mantle. Crust. The Crust. This is where we live!. The Earth’s crust is made of:. Continental Crust. Chapter 12.2 BC Science 10. A Cross-Section of Earth. The Layers of Earth. Earth is over 1200 km thick and has four distinct layers:. Crust. – outer solid rock layer (granite on land, basalt in oceans). Volcanism is mostly focused at plate margins. Pacific Ring of Fire. This map shows the margins of the Pacific tectonic plate and surrounding region. The red dots show the location of active volcanism. Notice how the majority of the volcanism is focused in lines along the plate boundaries? For this region is the area known as the “Pacific Ring of Fire”.. Volcanism is mostly focused at plate margins. Pacific Ring of Fire. This map shows the margins of the Pacific tectonic plate and surrounding region. The red dots show the location of active volcanism. Notice how the majority of the volcanism is focused in lines along the plate boundaries? For this region is the area known as the “Pacific Ring of Fire”.. 6. th. year Geography. Learning Outcome. Revise Core Book. Chapters 1 – 3. Plate Tectonics. Earthquakes. Volcanoes. Examine the exam questions on these topics. Theory of Plate Tectonics. Earths plates move. Beloussov. (1907-1990). Famous opponent of plate tectonics. Structural Geologist and Geodynamicist. Director of Geodynamics . Dept. , . Inst. of the Physics of the Earth. Member of Soviet Academy of Sciences (appointed 1953). Where are the major zones of volcanism?. What are the parts of a volcano?. How do volcanic landforms differ?. Copyright © McGraw-Hill Education. Volcanoes. Review. convergent. New. volcanism. hot spot. Theory of Plate Tectonics-. Theory that states the earth’s crust is broken into plates that float on lower mantle. Theory combines the theories of . continental drift . and . sea floor spreading . It states how and why . : Western US. Authors: Ruth Powers (UNAVCO Master Teaching-in-Residence); . Becca Walker and Shelley Olds (UNAVCO). Activity Outcomes. Learners should be able to…. Describe how the locations of earthquakes, volcanoes, and velocity vectors from GPS stations in the Western United States inform us about plate boundary zones. Structure of the Earth. What are the different layers of the Earth?. Structure of the Earth. Inner core. 6000. °C. Solid metal. Structure of the Earth. Outer core. 4500-6000. °C. Liquid metal. Structure of the Earth. http://sos.noaa.gov/datasets/Land/paleo.html. Animations. . On the move…. Plate Tectonics: . the rocky history of an idea. Ever notice that the shore lines of South America and Africa seem to fit together?. Enter . Silently. Grab Materials. Begin Do Now. Write in your planner for the week. Open your notebook to the front of page 17. . I Do (5 min) . Topic: . Earth. Front Page 17 Title: “How to Make a Concept Map”.