Transcript Volcanoes
Volcanoes Made By: Olivia Lawley and Anna Mattern Composite Volcanoes They are also known as strato volcanoes They are formed by alternating layers of lava and rock fragments They often form snowcapped peaks Composite Volcanoes (continued) They are usually long and cone shaped but also come in many other shapes and sizes They are formed during the eruptions that releases lava, when it cools near the volcano, that is what gives it its shape Complex Volcanoes It has been said that all volcanoes can be classified as complex because they are all made up of multiple flows, ash layers, domes, etc. They are called complex volcanoes because their system is not simple Complex Volcanoes (continued) They are formed because of changes of their characteristics during eruptions Also, because of the location of the vents in certain areas of the volcano Spatter Volcanoes When the erupting lava has enough exploding gases in it to stop the making of lava flow but not enough to shatter it, the lava is torn and it is classified as “spatter” When spatter falls back into the Earth, it comes together and forms spatter cones (shown on the right) Spatter Volcanoes (continued) Spatter volcanoes can be found in the Hawaiian islands These volcanoes come in many shapes and sizes because the lava is not fully solid when it lands, unlike cinder and ash Parts of a Volcano Why Do Volcanoes Occur? They occur when the Earth’s plates pull apart causing magma to rise to the surface They can also occur over hot spots and plates that drive into each other What are Plate Tectonics and How Do They Work? Plate tectonics is a theory that the Earth’s crust is made up of “plates” that are in constant motion They slide against each other, move apart, or smash together When they slide against each other, it causes the forming of fault lines How Do the Earth’s Plates Move and What Happens When They Collide? They move because of intense heat in the core It moves in patterns called “convection cells” that form when material rises, cools, and sinks down Collision creates mountains, subduction zones, and deep ocean trenches depending on the circumstances Where Do Many of the World’s Volcanoes Occur and Where Did This Area Get Its Name? Many of the world’s volcanoes occur in the Ring of Fire It got its name because it is roughly horseshoe shaped, marks the area of greatest seismic activity, and it is where the most volcanic activity happens What are Hot Spots? Hot Spots are portions of the Earth’s surface that experience significant volcanism, normally located near plate boundaries Some hot spots of the world include Hawaiian, Yellow Stone, Mackenzie, and Matachewan Hot Spots Volcanic Hazards Flowing Lava Doesn’t move very fast Destroys property Melts snow and ice which makes floods Pyroclastic Flows Fluidized masses of fragments and gases that move rapidly in response to gravity Can form in several ways Ash Consists of jagged rock and glass Hard, abrasive, mild, and corrosive Conducts electricity when wet Is spread over broad areas by wind Can turn daylight into complete darkness How To Deal With a Volcanic Eruption Follow authorities‘ directions Close all windows, doors, and dampers Stay indoors If outdoors, seek shelter or car Have a plan ready Volcanic Emergency Kit Goggles Dust Musk (one for each family member) Battery Operated Radio Food and Water Protective Clothing First Aid Kit Flashlight and Extra Batteries Historic Volcano- Mount Pinatubo Mount Pinatubo erupted on June 15th, 1991 This eruption took place on the island of Luzon in the Philippines Killed 800 people and left 100,000 people homeless Historic Volcano- Mount Pinatubo Lots of sulfur dioxide was discharged into the air resulting in a decrease in temperature worldwide over the following years after the eruption It is part of a chain of composite volcanoes along the Luzon Arc on the west side of the island Active Volcano- Merapi It is located in Java, Indonesia Its size rises to 9,551 ft. or 2,911 meters Merapi is the most active of all Indonesia's 130 volcanoes Vegetation grows at its base Active Volcano- Merapi It has erupted several times including, 1786, 1822, 1872, 1930, possibly 1976, and several times in 1998 One of its largest eruptions was in 1006 and spread ash throughout all of Java Bibliography Electronic Sources www.google.com www.ask.com http://pubs.usgs.gov/gip/volc/types.html http://library.thinkquest.org/17457/volcanoes/types.php Non-Electronic Sources Our Violent Earth By: The National Geographic Society Earth Science Textbook By: Prentice-Hall Merriam-Webster’s School Dictionary Volcanic Eruption Video THE END!! Thank You For Coming And We Hope You Enjoyed Our Presentation! -Olivia and Anna