PPT-Volcanoes and Earthquakes!

Warm Up Why do you think magma rises Consider an ice cube floating at the top of a glass of water Objective SWBAT Describe at least two of the three types of volcanoes and how they form Agenda. Lava Video. Volcanoes, magma, and lava. Volcanoes are weak spots in the crusts where molten material, or magma, comes to the surface.. When magma reaches the surface it is called lava.. The lava released during volcanic activity builds up Earth’s surface, it is a constructive force.. Chapter 5. Rigid Earth to Plate Tectonics. Learning Objectives. Know the different types of volcanoes and their associated features. Understand the relationship of the volcanoes to plate tectonics. Know what geographic regions are at risk from volcanoes. 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!. Basaltic Lava – low silica content, low viscosity, low gas content. Hot spots – magma moves up from lower mantle and plates move over it . Ex. Hawaii. (note: see video on favorites). Shield Volcanoes. Martin . Ménégoz. , Francisco . Doblas. -Reyes, . Virginie. . Guemas. , . Asif. Muhammad. EC-Earth Meeting, Reading, May 2015. Reading, May 2015. 2. Introduction. Major eruptions bring large amounts (Tg) of particles in the stratosphere.. 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”.. Do Now: How many natural disasters can you name. ?. HW: Article . due Wednesday. Volcanoes are responsible for:. producing . most of the water . on . Earth. .. modifying . the . Earth’s atmosphere.. Earthquakes result from sudden motions along breaks in Earth’s crust and can affect landforms and societies.. An entire branch of Earth science, called . seismology. , is devoted to studying earthquakes.. 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. Divergent. Convergent. Transform. Three types of plate boundary. Spreading ridges. As plates move apart new material is erupted to fill the gap. Divergent Boundaries. Iceland has a divergent plate boundary running through its middle. Volcanoes. Volcano:. mountain that forms in Earth’s crust when molten material (magma) reaches the surface. . Remember, . magma . is molten rock below ground; . lava. is molten rock at the surface. . The lithosphere is broken up into large sections called plates. They move around very slowly.. The movement can cause mountains and valleys to form.. Earthquakes usually happen at plate boundaries, called faults, when the plates get caught and then jerk loose. . 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. Structure of the Earth. Key terms . Earth’s Structure- How the Earth is made up beyond what we see. . Plate Tectonics- Understanding how the Earth’s surface is divided up into sections. . Inner Core- The central part of the Earth; made of solid iron. .