7th Grade Ch. 3 Sec. 1 Volcanoes and Plate Tectonics
Upcoming SlideShare
Loading in...5

7th Grade Ch. 3 Sec. 1 Volcanoes and Plate Tectonics






Total Views
Views on SlideShare
Embed Views



0 Embeds 0

No embeds


Upload Details

Uploaded via as Microsoft PowerPoint

Usage Rights

© All Rights Reserved

Report content

Flagged as inappropriate Flag as inappropriate
Flag as inappropriate

Select your reason for flagging this presentation as inappropriate.

  • Full Name Full Name Comment goes here.
    Are you sure you want to
    Your message goes here
Post Comment
Edit your comment

7th Grade Ch. 3 Sec. 1 Volcanoes and Plate Tectonics 7th Grade Ch. 3 Sec. 1 Volcanoes and Plate Tectonics Presentation Transcript

  • Ch. 3 Sec. 1 Volcanoes & Plate Tectonics
    • weak spot in crust where molten material comes to surface
  • magma
    • molten rock from mantle beneath Earth's surface
  • lava
    • magma that reaches surface
  • pillow lava lava entering the ocean
  • buried road in Hawaii
  • After lava has cooled, it forms solid rock.
    • Although you might not wish to touch lava with a "ten foot pole“, this potentially hazardous activity is all in a day's work for a volcanologist.
    • The long pole contains a special probe that can measure the temperature of the lava.
  • Ring of Fire
    • major volcanic belt formed by many volcanoes that rim Pacific Ocean
  • Volcanic belts form along the boundaries of Earth’s plates.
  • Ring of fire
  • most volcanoes occur: along diverging plate boundaries along converging plate boundaries mid-ocean ridge in subduction zones
  • volcanoes at converging boundaries subduction causes oceanic crust to sink through a deep-ocean trench into mantle  crust melts & forms magma  magma rises back to surface  forms volcanoes
  • Volcanoes often form where two oceanic plates collide or where an oceanic plate collides with a continental plate. In both situations, an oceanic plate sinks through a trench. Rock above the plate melts to form magma, which then erupts to the surface as lava.
  • island arc
    • string of islands created by volcanoes
    • examples:
    • Japan
    • New Zealand
    • Caribbean islands
    • Phillipines
  • hot spot
    • area where magma from deep within mantle rises & melts thru. crust
    • can occur:
      • in middle of plates
      • on or near plate boundaries
      • under continents
    • eg:
      • Hawaii
      • Yellowstone National Park
  • Hot Spot Volcanoes
    • A volcano forms above a hot spot when magma erupts through the crust and reaches the surface.
  • The Hawaiian Islands formed one by one over millions of years as the Pacific plate drifted over a hot spot.