1 / 9

Volcanoes Magma and Lava

Volcanoes Magma and Lava. When we talk about volcanoes. What caused the magma to form What type of magma What type of lava Plate boundaries What type of volcano forms Examples of places on Earth. Magma formation.

lave
Download Presentation

Volcanoes Magma and Lava

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 Magma and Lava

  2. When we talk about volcanoes • What caused the magma to form • What type of magma • What type of lava • Plate boundaries • What type of volcano forms • Examples of places on Earth

  3. Magma formation • Remember the mantle is SOLID and needs special conditions to turn into magma • Magma will be created from the mantle and rise to the surface for different reasons: • Decrease in pressure • Increase in temperature • Increase in water (lowering the melting temp of the mantle)

  4. Magma Formation • Decrease in pressure • A tear or crack in Earth’s surface decreases the pressure on the mantle and liquid magma forms • The magma is less dense than the rock around it so it rises to the surface • This occurs at divergent boundaries

  5. Increase in temperature Some areas of the mantle are extremely hot, this melts the mantle and forms magma The magma rises to the surface because it is less dense A hot spot in the lithosphere is created This does not occur at a plate boundary Magma Formation

  6. Magma Formation • Increase in water • An increase in the amount of water lowers the melting temperature of the mantle • This creates magma that rises to the surface because it is less dense • This occurs at subduction boundaries • Subducting Plate

  7. Types of Magma • Magma is determined by its viscosity • Viscosity is determined by the amount of silica in the magma What is viscosity?

  8. Types of Magma • Viscosity – a substances resistance to flow • Number the following items from most viscous to least viscous Water Ketchup Oil Shampoo 4 1 2 3

  9. Types of Magma • Magma that is very viscous has A LOT of silica and does NOT flow very easily and is VERY EXPLOSIVE • Rhyolitic Magma-high Silica • Continental Crust • Magma that has a low viscosity does not have a lot of silica and flows very easily • Basaltic Magma-low silica • Directly from mantle • Magma that is in between is called intermediate, this lava is also EXPLOSIVE • Andesitic-medium silica • Subduction Boundaries

More Related