Volcanoes

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  • Talk about this volcano when it erupted and what it is doing right now.
  • MASS, DENSITY, AND ESCAPE VELOCITY The Earth's mass is about 5.98 x 10 24 kg. The Earth has an average density of 5520 kg/m3 (water has a density of 1027 kg/m3). Earth is the densest planet in our Solar System. To escape the Earth's gravitational pull, an object must reach a velocity of 24,840 miles per hour (11,180 m/sec).
  • The Earth is made of many different and distinct layers. The deeper layers are composed of heavier materials; they are hotter, denser and under much greater pressure than the outer layers. Core : The Earth has a iron-nickel core that is about 2,100 miles in radius. The inner core may have a temperature up to about 13,000°F (7,200°C = 7,500 K), which is hotter than the surface of the Sun. The inner core (which has a radius of about 750 miles (1,228 km) is solid. The outer core is in a liquid state and is about 1,400 miles (2,260 km) thick.
  • There are lots of uncertainties about why volcanoes form, because scientists have to rely on models based on rock samples and other data.
  • There are lots of uncertainties about why volcanoes form, because scientists have to rely on models based on rock samples and other data.
  • Volcanoes

    1. 1. Liquid Hot Magma. Volcanoes Tungerahua Volcano, Ecuador Picture by Alcinoe Calahorrano
    2. 2. Volcano Stats <ul><li>Definition of Volcano </li></ul><ul><ul><li>Mountain that forms when molten rock (magma) is forced to the Earth’s surface </li></ul></ul><ul><li>Number of active volcanos = ? </li></ul><ul><ul><li>20 erupting right now (50-60/year) (160/decade) </li></ul></ul><ul><li>Number of volcanologists = 1,500 </li></ul>
    3. 3. <ul><li>Nonexplosive Eruptions </li></ul><ul><li>Explosive Eruptions </li></ul>Volcanic Eruptions What is Lava ? -magma that flows onto the Earth’s surface Lava fountain Lava flow
    4. 4. Volcano Model Demonstration
    5. 5. 1. What did you learn? Write/draw this in your science journal. Volcanoes form around vents that release magma onto the Earth’s surface. Vents Lava Magma chamber
    6. 6. <ul><li>High water content </li></ul><ul><ul><li>More likely to be !!! </li></ul></ul><ul><li>High content </li></ul><ul><ul><li>More likely to be !!! </li></ul></ul><ul><ul><li>Why ? </li></ul></ul><ul><ul><ul><li>Silica has a thick, stiff consistency </li></ul></ul></ul><ul><ul><ul><ul><li>Flows slowly </li></ul></ul></ul></ul><ul><ul><ul><ul><li>Tends to Harden in the volcano’s vent </li></ul></ul></ul></ul>The Composition of Magma Determines whether it is explosive or not! water silica EXPLOSIVE EXPLOSIVE
    7. 7. Explosive Volcano Model Demonstration
    8. 8. <ul><li>a. What physical event causes explosive eruptions? </li></ul><ul><li>b. Would high water content increase the likelihood of having an explosive eruption? </li></ul><ul><li>c. Would high silica content increase the likelihood of having an explosive eruption? </li></ul>2. What did you learn? Write/draw this in your science journal.
    9. 9. What Erupts from a Volcano? Lava can be thick or thin. Blocky lava Pahoehoe Aa Pillow lava
    10. 10. What Erupts from a Volcano? <ul><li>Pyroclastic material </li></ul><ul><li>Rock fragments created by eruptions </li></ul><ul><ul><li>magma explodes from volcano and solidifies in the air </li></ul></ul><ul><ul><li>existing rock is shattered by powerful eruptions </li></ul></ul>Volcanic blocks Volcanic bombs Lapilli Volcanic ash EXPLOSIVE
    11. 11. How do volcanoes affect the Earth? <ul><li>Flows and Fallouts </li></ul><ul><li>hot ash can flow really quickly </li></ul><ul><ul><li>Knock down buildings </li></ul></ul><ul><ul><li>Dam rivers (flooding/drought) </li></ul></ul><ul><ul><li>Kill crops and livestock </li></ul></ul><ul><li>Climatic Changes </li></ul><ul><ul><li>Ash & Gases can block sunlight </li></ul></ul><ul><ul><ul><li>Drop average global temperature noticeably </li></ul></ul></ul>
    12. 12. Types of Volcanoes Shield volcano Cinder cone volcano Composite volcano
    13. 13. Craters, Calderas, and Lava Plateau <ul><li>Crater </li></ul><ul><li>From explosions of material out of the vent and the collapse of material back into vent </li></ul><ul><li>Caldera </li></ul><ul><li>Much larger depression that forms when magma chamber empties and its roof collapses </li></ul><ul><li>Lava Plateau </li></ul><ul><li>Forms when lava erupts from long cracks, or fissures, and spreads out evenly (thousands of km) </li></ul>
    14. 14. What causes volcanoes? <ul><li>The Formation of Magma </li></ul><ul><li>Mantle rock melts when the temperature increases </li></ul><ul><li>or the pressure decreases . </li></ul>
    15. 15. What causes volcanoes? <ul><li>Where Volcanoes Form </li></ul><ul><li>Tectonic Plate Boundaries!!! </li></ul>~75% world’s active volcanoes in Ring of Fire
    16. 16. What causes volcanoes?
    17. 17. What causes volcanoes? Hot Spots
    18. 18. <ul><li>Measuring Small Quakes </li></ul><ul><ul><li>Before eruption, increase in number & intensity </li></ul></ul><ul><li>Measuring Slope </li></ul><ul><ul><li>Bulges may form with magma (tiltmeter) </li></ul></ul><ul><li>Measuring Volcanic Gases </li></ul><ul><ul><li>Outflow of volcanic gases </li></ul></ul><ul><ul><ul><li>Sulfur dioxide, carbon dioxide </li></ul></ul></ul><ul><li>Measuring Temperature from Orbit </li></ul><ul><ul><li>Measure changes in temperature over time </li></ul></ul>How do volcanologists predict eruptions?
    19. 19. You should not be a Volcanologist if…. <ul><li>You don’t like hiking, backbacking, rockclimbing, etc. </li></ul><ul><li>You are not interested in experiencing extreme temperatures and heights. </li></ul><ul><li>If you don’t like to travel to incredible places and see breathtaking views of the world. </li></ul>Robert McGimsey USGS A. Ozerov
    20. 20. Eruption Anticipation Activity
    21. 21. <ul><li>Place 10mL of baking soda in center of a sheet of bathroom tissue. Fold the corners over the baking soda and crease the edges so that they stay in place. Place the tissue packet in the middle of a large disposable pan. </li></ul><ul><li>Put modeling clay around the top edge of a funnel. Turn the funnel upside down over the tissue packet. Press down to make a tight seal. </li></ul><ul><li>Put safety goggles on and add 50mL of vinegar and several drops of liquid dish soap to a 200mL beaker, and stir. </li></ul><ul><li>Predict how much time will elapse before your volcano erupts. WRITE THIS DOWN! </li></ul><ul><li>Pour the liquid into the upturned funnel. Using a stopwatch, record the time you began to pour and the time your volcano erupts. </li></ul><ul><li>How close was your prediction? </li></ul>
    22. 22. <ul><li>a. Was your time prediction close to the real time of eruption? </li></ul><ul><li>b. Are the eruption times similar for every group? If not, give at least one reason why this might be. </li></ul><ul><li>c. How is our experiment different from predicting the eruption of a real volcano? </li></ul>4. What did you learn? Write/draw this in your science journal.

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