Loading presentation...

Present Remotely

Send the link below via email or IM


Present to your audience

Start remote presentation

  • Invited audience members will follow you as you navigate and present
  • People invited to a presentation do not need a Prezi account
  • This link expires 10 minutes after you close the presentation
  • A maximum of 30 users can follow your presentation
  • Learn more about this feature in our knowledge base article

Do you really want to delete this prezi?

Neither you, nor the coeditors you shared it with will be able to recover it again.


Formation of Stratovolcanoes

No description

Trent Yu

on 1 March 2013

Comments (0)

Please log in to add your comment.

Report abuse

Transcript of Formation of Stratovolcanoes

A guide to the birth of volcanoes How Are Stratovolcanoes formed?
Magma chamber Less dense magma in the mantle rises up and melts through the crust. It gathers in a reservoir, a weak part of the rock, called a magma chamber. This creates pressure on the earth's crust. When the pressure becomes too large, the magma forces its way to the surface. If the area above the chamber is blocked or strong, pressure builds up and the volcano eventually erupts explosively. Building a volcano Repeated eruptions form layers of rock and ash, gradually forming layers. This eventually builds the volcano up to create the cone shaped stratovolcano. Silica-rich magma Famous Stratovolanos Mount Saint Helens is one of the most famous volcanoes in the US. The stratovolcano erupted when an earthquake caused part of the volcano to slide away. The magma was exposed to lower pressure, and the volcano erupted. Other notable volcanoes are Krakatoa in Indonesia, Eyjafjallajokull in Iceland, and Mt. Tambora in Sumbawa, Indonesia. Heat and pressure in a subduction zone (when one a oceanic plate sinks under a continental one) squeezes water out of the subduction plate. That makes the pressure drop, forming magma. A subdution zone forces water into the mantle, forming magma. Less dense magma works its way through to the magma chamber. Eruptions of silica-rich magma form layers of ash and rock to build the volcano up. Eventually, it explodes, like Mt. Saint Helens in Washington did. The magma chamber is where magma is stored before an eruption Layers of ash and lava build up to form a stratovolcano The magma that builds up the volcano up must be silica-rich, as runny magma will just flow off gently and form a shield volcano. Runny Magma Sticky, thick magma Silica-poor vs silica-rich
lava Mt Saint Helens Before and After Subduction Zone Summary
Full transcript