volcanic activity. silica earth’s crust and mantle are mostly made of silica the more silica in...
TRANSCRIPT
Silica
Earth’s crust and mantle are mostly made of silica
The more silica in the magma, the thicker it is
SilicaMagma with a lot of silica makes light-colored lava that is very thick
When high silica lava cools, it makes rocks like rhyolite, pumice and obsidian
SilicaMagma that does not have much silica moves quickly and is thin.
Low silica magma is dark colored and makes rocks like basalt
Quiet Eruptions
Quiet eruptions are when magma flows out easily from the vent and volcano sides.
Quiet eruptions produce two types of lava
Explosive Eruptions
If magma is thick, the eruption is explosive.
The magma builds up and plugs the pipe, building pressure.
The erupting gases push the magma out quickly.
Explosive Eruptions
The force of the explosion splits the lava into several pieces.
Ash are smallest pieces
Cinder are pebble-sized particles.
Stages of a Volcano
There are three stages of a volcano
Active: The volcano is erupting or may erupt in near future
Dormant: The volcano is sleeping and may awake in the future.
Other Types of Volcanic Activity
Hot springs form when water around the volcano is heated by magma.
Geysers are created when this hot water gets trapped under ground and builds pressure until it erupts.
Geothermal Energy
Geothermal energy uses water heated naturally by magma to create energy.
Steam spins the turbines which turns a generator to make electricity.
Monitoring Volcanoes
We are getting better at predicting volcanoes.
Many small earthquakes around a volcano are common before an eruption.
Volcano Hazards
People are dormant volcanoes can be caught by surprise.
Quiet eruptions are dangerous because the lava sets fire to everything.