1 / 14

Volcanoes

Volcanoes. By Amber Hiltunen. What Are Volcanoes. Volcanoes are breaks in the earth’s crust where magma comes through and cools above the surface As pressure builds, the magma is forced up and carves through solid rock and creates a central vent. Where Volcanoes Occur. In divergence zones

zhen
Download Presentation

Volcanoes

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. Volcanoes By Amber Hiltunen

  2. What Are Volcanoes • Volcanoes are breaks in the earth’s crust where magma comes through and cools above the surface • As pressure builds, the magma is forced up and carves through solid rock and creates a central vent

  3. Where Volcanoes Occur • In divergence zones • Where the plates of the crust and mantle are pulling apart • In convergence zones • Where the plates are coming together and occupying the same place • Over hot spots • In the mantle where rock melts to generate magma

  4. Types of Volcanoes • Cinder Cone • Composite (Strato-) Volcano • Lava Dome • Shield Volcano • Lava Plateau • Go here for more information on the five different types http://vulcan.wr.usgs.gov/Photo/Pictograms/volcano_types.html

  5. Cinder Cone • Explosive • Formed by pieces of solidified lava thrown central vent • Smallest type • Very rapid growth, but usually to < 1000 feet

  6. Paricutin • Cinder cone in Mexico • It has a large central crater • One side is higher than the other • Usually occurs in groups along a fault

  7. Composite(Strato-) Volcano • Explosive • Has alternating layers of cinder and ash • They can reach several thousand feet high • The crater may change form rapidly • Can develop secondary cones • An example is Mount St. Helens

  8. Mount St. Helens • Composite(Strato-) Volcano • Located in Washington • 8,364 feet high • Erupted in 1980 after being dormant since 1857

  9. Lava Dome • Somewhat effusive • Highly explosive • Sets up quickly • Builds up until explosion • The lava that comes out is viscous

  10. Shield Volcano • Effusive (quiet) • Has highly fluid lava • It spreads before set-up • Gently rises • Has a wide, steep-sided central depression

  11. Lava Plateau • Effusive • Non-viscous lava flows from cracks • Forms horizontal strata, or flows down slope • Successive flows my produce deposits thousands of feet thick

  12. Review

  13. More Information • Michigan Tech's Volcanoes Website • Here you will find information on what a volcano is, what’s happening now, and earth’s active volcanoes • Volcanoes Online • Here you can find information on the structure of volcanoes, types of volcanoes, and volcanic features

  14. Quiz • Volcano Quiz • Answers to Quiz

More Related