Volcanoes Deepa&Kirti

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  • 1. Deepa S Beli Keerti Yadav VOLCANOES
  • 2. INTRODUCTION
  • 3. HISTORY
    • On Aug 24, A.D. 79, Vesuvius volcano suddenly exploded in Roman cities.
    • After that 100 of yrs it was considered as “Extinct”.
    • Then the word ‘Volcano’ originates from “Vulcan” – God of fire in Roman mythology .
  • 4. NATURE
    • conical hill or mountain built around the vent.
    • The term volcano also refers to opening.
    • Built by accumulation of their own eruptive product lava,bomb,flows & tephra.
  • 5. MEANING
    • “ When pressure from the molten rock beneath the earth’s surface becomes too great the rock usually accompanied by lava or gases, escapes through a fissure or vent in crust of earth”.
  • 6. COMPOSITION
    • Volcano mainly consists of molten rock and
    • other liquids.
    • a) Liquid composed of O, Si, Al, Fe, Mg, Na,
    • Ca, Mn, K.
    • b) Magma-molten rock below the earth’s
    • surface.
    • c) Lava-fluid erupted from volcanic vent.
  • 7.   Fountaining lava and volcanic debris during the 1959 Kilauea Iki eruption of Kilauea Volcano, Hawaii.
  • 8. TYPES OF VOLCANOES
    • Cinder Volcano
    • Composite Volcano
    • Shield Volcano
    • Lava Domes
  • 9. CINDER VOLCANOES
    • Simplest
    • Built from particle & blobs of congealed lava.
    • Lava solidifies & fall from single vent.
    • Numerous in West North America .
     
  • 10.  
  • 11.     Parícutin Volcano, Mexico, is a cinder cone rising approximately 1,200 feet above the surrounding plain.
  • 12. COMPOSITE VOLCANOES
    • Steep sided, symmetrical cones.
    • Built from layer of lava flow, ash, cinder.
    • Rises up to 8000 ft from base.
    • Conspicuous volcano in
    • a] Mt.Fuiji, Japan.
    • b] Mt.Shasta, California .
  • 13.  
  • 14.     Shishaldin Volcano, an imposing composite cone, towers 9,372 feet above sea level in the Aleutian Islands, Alaska.
  • 15. SHIELD VOLCANOES
    • Slow process volcano
    • Built from fluid lava.
    • Flows in all direction from central vent like warrior’s shield.
    • Linear chains in Hawaiian Island.
    • a) Kilauea
    • b) Mauna Loa
  • 16.  
  • 17.     Mauna Loa Volcano, Hawaii, a giant among the active volcanoes of the world; snow-capped Mauna Kea Volcano in the distance.
  • 18. LAVA DOMES
    • Built from small bulbous masses of lava.
    • Viscous to flow any great distance.
    • Piles over & around the vent.
    • Expansion makes outer surface cool & harder.
    • Eruption of Katmai volcano in Alaska in 1912
  • 19.  
  • 20. The Novarupta Dome formed during the 1912 eruption of Katma Volcano, Alaska.
  • 21. VOLCANIC ERUPTION
    • During an episode of activity, a volcano commonly displays a distinctive pattern of behavior.
  • 22. TYPES OF ERUPTIONS
    • Eruption is often labeled with the name of well known volcanoes, where characteristic behavior are similar .
    • Strombolian eruption
    • Volcanian eruption
    • Vesuvian eruption
    • Pelean eruption
    • Hawaiian eruption
  • 23. STROMBOLIAN ERUPTION
    • Observed in 1965, during activity of Irazua volcano in Costa Rica.
    • Huge clots of molten lava from ejected from summit crater.
    • Forms luminous arcs through the sky.
    • From the flanks of the cone, lava clots combined to stream down the slope in fiery rivulets.
  • 24.   Irazua volcano in Cost Rica,1965.
  • 25. VULCANIAN ERUPTION
    • Observed at Paricutin volcano in Mexico, 1947.
    • Explodes dense cloud of ash-laden gas from the crater.
    • Rises very high & forms whitish clouds near the cone.
  • 26.   Parícutin Volcano, Mexico, 1947. 
  • 27. VESUVIAN ERUPTION
    • Explodes great quantities of ash-gas laden
    • Forms cauliflower shaped clouds high above the volcano.
    • Observed at Mt.Vesuvius in Italy in A.D. 79.
  • 28.     Mount Vesuvius Volcano, Italy, 1944.
  • 29. HAWAIIAN ERUPTION
    • Observed in Hawaii of Mauna Loa in 1950.
    • Molten incandescent lava spurts from a fissure on the volcanoes left zone.
    • Lava may collect in old pit crater to form lava lakes.
  • 30.     Mauna Loa Volcano, Hawaii, 1950.
  • 31. PELEAN(GLOWING CLOUD) ERUPTION
    • Observed in Mayon volcano in Philippines in 1968.
    • Large quantity of gas, dust, ash & incandescent lava.
    • Lava moved down slope at velocity of 100 miles per hour which look like tongue shaped.
  • 32.
    • The most powerful eruptions are called "plinian" and involve the explosive ejection of relatively viscous lava.
  • 33.     Mount St. Helens about noon, May 18, 1980 .
  • 34. SUBMARINE VOLCANOES
    • Submarine volcano & volcanic vents are common features on zones of ocean floor.
    • Disclose their presence by blasting steam & rock debris high above the surface of the sea.
    • With great depth & tremendous depth of water volcano, confines the pressure, prevents the formation of steam & gases .
  • 35.  
  • 36.     Submarine eruption of Myojin-sho Volcano, Izu Islands, Japan, on September 23, 1952.
  • 37. EXTRATERRESTRIAL VOLCANISM
    • Planetary exploration is began in 1960’s with it’s product on Mars,Moon &Venus.
    • Pounds of volcanic rock collected during various Apollo lunar landing mission.
    • From 1976 – 79 Viking mission studied the volcanoes on Mars i.e. about Olympus Mons volcano.
  • 38.    
  • 39. MONITORING & RESEARCH
    • Began in 1912 , by Thomas A. Jaggar.
    • Founded Hawaiian volcano observatory (HVO) on rim of Kilauea’s Caldera.
    • Monitoring of Seismic activity preceding.
    • Records & analysis an volcanic phenomenon which includes ground moments earthquakes .
  • 40. VOLCANO & PEOPLE
    • Volcanic materials breaks down to form some fertile soils on earth.
    • People use volcanic products as construction materials.
    • As abrasive & cleaning agents.
    • Raw materials for many chemical & industrial uses.
    • Internal heat of some volcanic system has been harnessed to produce geothermal energy.
  • 41. CONCLUSION
  • 42.