PPT-Volcanoes and Earthquakes.

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. 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. 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. 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. 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”.. VOLCANOES.. What is a volcano?. A volcano is a mountain that opens . below . to a pool of molten rock . called a magma chamber below . the surface of the earth. When . the pressure . builds up, eruptions take place. . rd. graders. By Amy Zimmerman. what I hope my students learn…. What a volcano is.. Understand that there are 3 main types of volcanoes.. Understand the process of eruption. . Know all the different parts of a volcano.. 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.. 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. . 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. .