PPT-Volcanoes: Eruptions and Impacts

What are volcanoes Does anyone know what a volcano is A volcano is a landform usually a mountain where liquid rock erupts through the surface of the planet The name volcano has its origin from the name of Vulcan a god of fire in Roman mythology. 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. Lava begins as . . , which usually forms in the asthenosphere. The materials of the asthenosphere are under great pressure. Liquid magma is . . dense than the solid material around it. Therefore, magma flows upward into any cracks in the rock above. As magma rises, it sometimes becomes trapped beneath layers of rock. But if an opening in weak rock allows the magma to reach the surface an . 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.. Target #16- I can summarize the conditions needed for magma to form. Despite the high temperature in the mantle, most of the layer remains solid due to extreme pressure. Magma: . liquid rock produced under Earth’s surface. By Robbie Barker, Maximilian Bryson, and Brendan . P. etrili. What is a volcano. A volcano is an opening in the Earth’s surface through which magma rises.. Formation of volcanoes. 1.Most volcanoes occur at colliding boundaries.. More than 2,000 years ago, Pompeii was a busy Roman city near the sleeping volcano Mount Vesuvius. People did not see Vesuvius as much of a threat. Everything changed when Vesuvius suddenly erupted and buried the city in a deadly blanket of ash that was almost 20 ft. thick!. Describe how the locations of volcanoes are related to plate tectonics.. Suggest why volcanoes are found at convergent and divergent plate boundaries.. Describe how . intraplate. volcanoes form.. Volcanic activity takes place primarily at . 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. Volcanoes. Shield. Composite. Cindercone. There are . three. types of volcanoes:. Formed by layer after layer of lava.. Usually have low silica content, and gases can escape easily.. Has quiet eruptions.. 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. . About 1500. Bellringer. Begin volcano video and questions. Objective. Pick one way to trigger a tsunami (1). Include one real life example (1). Describe how a tsunami wave is different from a wind wave (2).