1 / 21

Factors Influencing Violent and Quiet Volcanic Eruptions

Understand factors that determine the intensity of volcanic eruptions, including magma composition, viscosity, and gas content. Explore volcanic explosivity, lava types, and eruption aftermath.

alberte
Download Presentation

Factors Influencing Violent and Quiet Volcanic Eruptions

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Section 9.2 Volcanic Eruptions

  2. What FACTORS determine if a volcano erupts violently or quietly?

  3. Quiet eruptions Hawaii & Iceland https://www.youtube.com/watch?v=fmCJSS2YAP0

  4. Explosive,violent eruption https://www.youtube.com/watch?v=IhU6jml6NY4

  5. Page 121 Felsic magma Mafec* magma Feldspar, silica magnesium and iron

  6. Which has a HIGH viscosity? Resistance to flow honey water

  7. MAFIC magma • Dark colored minerals: • Magnesium and iron Fe • Olivine, pyroxene, Hornblende, augite, biotite • Less than 50% silica • LOW viscosity FELSIC magma • Light colored minerals: • Quartz, orthoclase Feldspar • More than 60% silica • HIGH viscosity

  8. Geode CD-ROM Lesson 1. Nature of Volcanic Eruptions And Lesson 2. Materials Extruded During Volcanic Eruptions

  9. Bell-work Pyroclastics consist of …… - - - - - - - - Ash Cinders Lapillii Glass Pumice Bombs Blocks Tuff (welded ash)

  10. Bell-work 4. What is 1 difference and 1 similarity between a … Pyroclastic flow and a Lahar

  11. Volcanic Explosivity Index How to measure a volcanic eruption

  12. Paroxysmal • a sudden outburst of a violent eruption • an increase of periodic eruptions • An eruption with a (V.E.I.)Volcanic Explosivity Index of 5 (on a scale of 0-8)

  13. Lava Vocabulary Quiz 9.2 pyroclastic igneous • Hot, erupted glass, ash, and rock fragments. ________________ • All lava flows are this type of rock. _____________________ 3. A basaltic lava that results in smooth, ropelike surfaces: ____________ • Magma has a high viscosity because it contains over 70% of ________ • If the magma has a high gas content, the eruptions tend to be ________ • Because of their high silica content, this rock is light colored. ________ viscosity lava aa pahoehoe pillow lava pyroclastic ash silica cinders igneous metamorphic sedimentary non-explosive mafic explosive felsic pahoehoe silica explosive felsic

  14. Before the 1980 eruption After the VIOLENTeruption The summit and side has been blown away.

  15. A portion of the side of the mountain was “blown away” leaving the mountain less steep. Flatter terrain then before. *Construct the profile activity

  16. “I was walking along a path with two friends – the sun was setting - suddenly the sky turned blood red - I paused, feeling exhausted, and leaned on the fence - there was blood and tongues of fire above the blue-black fjord and the city - my friends walked on, and I stood there trembling with anxiety - and I sensed an infinite scream passing through nature." Edvard Munch

  17. An agonized figure wails against a blood red Norwegian skyline in Edvard Munch's “The Scream” (1893) in the National Gallery, Oslo, Norway The 1883 eruption of the volcano Krakatoa in Indonesia put so much ash into the atmosphere, it caused unusually intense sunsets throughout Europe in the winter of 1883-4, which Munch captured in his painting.

  18. Based upon the description… • What type of volcano was this? shield, stratovolcano, cinder cone 2. What type of magma erupted? mafic or felsic • What type of plate boundary does this volcano lie on? Convergent, divergent, transform • What would the eruption be on the V.E.I.

More Related