PPT-Volcanoes

Chapter 9 Lesson 2 Videos httpvideonationalgeographiccomvideokidsforcesofnaturekidsvolcanoes101kids Volcanoes 101 National Geographic httpswwwyoutubecomwatchvcQMB7o3SXOw. Gwen . Nytes. Composition. The magma in this type of volcano is made of basaltic-andesitic materials. The magma has an intermediate viscosity, so . it’s mildly explosive. It also consists of a lot of gases, so when the lava cools and hardens in the air, gas bubbles get trapped inside. The particles fall back down as cinders, and pile around the vent.. 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.. The Earths crust . The earths crust is in constant motion.. Volcanoes and earthquakes arise as sections of crust push . toghether. or pulled apart. Volcanoes and earthquakes are more common in certain parts of the world. By monitoring ground vibrations scientists can sometimes. 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.. 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 . 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.. 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 . 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. 1. An opening in Earth’s crust through which molten rock, ash and gases erupt.. 2.Volcano: The landform that develops around the opening.. 3. A way for Earth to release heat energy from the interior due to radioactive decay.. 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. .