PPT-Intro to Volcanoes

What is a Volcano Volcano a weak spot in the crust where molten rock magma comes to the surface Most volcanoes are located around subduction zones and hot spots Over 75 of worlds volcanoes are found . 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!. GO. What do you know already about volcanoes?. Let’s learn more. Click on the links below.. What is a volcano?. What is magma and what is lava?. What types of volcano are there?. What causes a volcano to erupt?. 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. 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:. 8. th. . Grade Science. Earth. ’. s crust is made up of huge slabs called . plates. , which fit together like a jigsaw puzzle. These plates sometimes move.. Between the Earth. ’. s crust and the . 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 . rin. uphill and down dale,. Knapping the chucky stones to pieces . wi. ’ hammers,. Like . sae. . mony. . roadmakers. run daft –. They say it is to see how the . warld. was made.. - Sir Walter Raleigh. Romans believed in Vulcan, their god of fire.. They thought that Vulcan worked at a hot forge, striking sparks as he made swords and armor for the other gods.. Hawaiians told legends of the wanderings of Pele, their goddess of fire.. Compare the features of volcanoes.. Describe the stages in volcano formation.. What are Volcanoes?. Volcanoes are vents through which molten rock and gas escape from a . magma chamber.. Volcanoes can differ. 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. . . . Cause. most volcanoes are formed when two of Earth’s plate collide. the collision drives one of the plates under another . the plate that is under the other one begins to melt-->this melted rock is known as magma. 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).