1. Volcano's Effects

2. Lava Flows These are streams of lava that come out of the volcano.
Move slowly:
People can get out of their way
Trees/homes/buildings all will burn if they are caught in the flow’s path.

3. Volcanic Ash Ash spews from the volcano.
This material can land on roofs, causing them to burn or collapse.
Ash is very heavy; it contains small pieces of rock.
Ash makes roads slippery, and can even bring down a modern airplane.

4. Mudflows Occur when loose rocks and soil mix with water
When volcanoes erupt, ice and snow on the volcano will melt and release large amounts of water.
Water mixes with loose rocks/soil
Mudflows can burry towns miles away from the volcano.

5. Pyroclastic Flows
These super hot gas clouds rush downhill and knock down and burn everything in their path.
The flow will leave a thick layer of volcanic rock fragment

6. Landslides The rapid movement of rock and soil downhill
A volcano’s side can collapse and start a landslide.
Caused by:
Magma moving underground
Earthquakes
Heavy rainfall

7. Air Quality Volcanoes stink!
They release hydrogen sulfide
Smells like rotten eggs
They release Carbon dioxide
Deadly gas with no smell
Gases mix with water in the air, which causes acid rain.
Ash gets into the air:
Mount St. Helens released so much ash that it blocked all the sunlight for days in the state of Washington.
Some volcanoes release so much ash that the world will cool 1- 2 degrees.

8. Positive Effects?
Lava flows cool and harden. Over time, the rock breaks down and it forms into rich soil.
Many highly productive farmlands are near volcanoes.
Great landscape of mountains and valleys:
People want to live near volcanoes.
People want to tour volcanoes.

9. How does an eruption happen?
Magma is made of silicon and oxygen.
Magma is also made up of gases.
1.) Gases in the magma begin to expand
2.) Gases have no where to escape
3.) Pressure builds up
4.) Gases blow up and out of the volcano

10. Lava Lava is magma that reaches Earth’s surface.
As magma makes its way up the volcano, it gets trapped in magma chambers.
When a chamber can no longer hold the magma, the chamber blows up, magma escapes, reaches Earth’s surface, and is then lava.

11. Ash
Pieces of volcanic rock fragments that are smaller than 2mm in diameter
Get carried long distances by the wind

12. Blocks Large heavy pieces of volcanic rock Some as big as houses
They are shot out and fall quickly back to Earth

13. Pyroclastic flow A cloud of superhot gases and rock fragments
These flows race downhill
They reach temperatures of 1500 degrees Fahrenheit
Travel at 100 mph
Most dangerous part of an eruption

14. Scientists Monitor Volcanoes
Many volcanoes can lay dormant for years, and then once again erupt.
Before eruptions, there are some warning signs:
Small earthquakes
Steam coming from the volcano
Changes to the ground
Streams around the volcano get warmer