Volcanoes are formed when magma from the Earth's upper mantle works its way to the surface and erupts. There are over 1,500 active volcanoes on Earth. Volcanic eruptions occur when pressure builds up from magma and gases below the Earth's crust, causing rock and lava to shoot from the volcano in explosive eruptions. Eruptions can cause dangerous flows of lava, ash, mudslides and floods that threaten nearby areas.

1. VOLCANOES
A volcano is a mountain that opens downward to a pool of
molten rock below the surface of the earth. When pressure
builds up, eruptions occur. Gases and rock shoot up
through the opening and spill over or fill the air with lava
fragments. Eruptions can cause lateral blasts, lava flows,
hot ash flows, mudslides, avalanches, falling ash and
floods. Volcano eruptions have been known to knock down
entire forests. An erupting volcano can trigger tsunamis,
flash floods, earthquakes, mudflows and rockfalls.

2. How are volcanoes formed?
Volcanoes are formed when magma from
within the Earth's upper mantle works its
way to the surface. At the surface, it erupts
to form lava flows and ash deposits. Over
time as the volcano continues to erupt, it will
get bigger and bigger.

3. What are the different stages of
volcanoes?
ACTIVE-one which has recently erupted and there
is a possibility that it may erupt soon.
DOMINANT-one which has not erupted in a
long time but there is a
possibility it can erupt in the
future.
EXTINCT-one which has erupted thousands of
years ago and there’s no
possibility of eruption.

4. ACTIVE
MT. BULUSAN
MAYON VOLCANO
MOUNT KANLAON

5. EXTINCT
MT. ASHITAKA MT. BUNINYONG

6. MT. FUJI MT. EDZIZA
MT. RAINIER
DOMANT

7. Why do volcanoes erupt?
The Earth's crust is made up of huge slabs
called plates, which fit together like a jigsaw
puzzle. These plates sometimes move. The
friction causes earthquakes and volcanic
eruptions near the edges of the plates. The
theory that explains this process is called
plate tectonics.

8. What are plate tectonics?
The theory of plate tectonics is a continents drifting
from place to place breaking apart, colliding, and
grinding against each other. The plate tectonic theory
is supported by a wide range of evidence that
considers the earth's crust and upper mantle to be
composed of several large, thin, relatively rigid plates
that move relative to one another. The plates are all
moving in different directions and at different speeds.
Sometimes the plates crash together, pull apart or
sideswipe each other. When this happens, it
commonly results in earthquakes.

9. How many volcanoes are there?
There are more than 1500 active volcanoes
on the Earth. We currently know of 80 or
more which are under the oceans. Active
volcanoes in the U.S. are found mainly in
Hawaii, Alaska, California, Oregon and
Washington.

10. The different types of volcanoes
Cinder Cones- are circular or oval cones made up of
small fragments of lava from a single vent
that have been blown into the air, cooled
and fallen around the vent.
Composite Volcanoes- are steep-sided volcanoes
composed of many layers of
volcanic rocks, usually made from
high-viscosity lava, ash and rock
debris. Mt. Rainier and Mount St.
Helens are examples of this type
of volcano.

11. Shield Volcanoes- are volcanoes shaped like a bowl
or shield in the middle with long
gentle slopes made by basaltic
flows. Basalt lava flows from
these volcanoes are called flood
basalts. The volcanoes that
formed the basalt of the Columbia
Plateau were shield volcanoes.
Lava Volcanoes- are formed when erupting lava
is too thick to flow and makes a
steep-sided mound as the
lava piles up near the volcanic
vent.

12. Volcano Safety Tips
•Have a disaster plan and know whether or not you
are at risk for danger
•Be prepared for mudslides, flash floods,
earthquakes, ash falling, acid rain and tsunamis.
•Prepare a disaster supplies kit for your home and
car. Include a first aid kit, canned food and a can
opener, bottled water, battery-operated radio,
flashlight, protective clothing, dust mask, goggles
and sturdy shoes.
•Don't forget, know all of your evacuation routes.

13. During a Volcanic Eruption
•Follow the evacuation order issued by authorities.
•Avoid areas downwind and river valleys downstream of the
volcano.
•Avoid areas downwind and river valleys downstream of the
volcano.
•If you’re trapped outdoors, seek shelter indoors.
•If you’re caught in falling rocks, roll into a ball and protect your
head.
•If you’re caught near a stream, be aware of mudflows and move to
higher ground.
•Protect yourself when ash falls by wearing long-sleeved shirts and
long pants.
•Use goggles to protect your eyes.
•Wear a dust mask and keep car engines off.

14. AFTER A VOLCANO ERUPTS
•Cover you mouth and nose. Volcanic ash can
irritate your respiratory system.
•Wear goggles and protect your eyes.
•Keep your skin covered.
•Clear roofs of ash, because the ash is very
heavy and can cause the building to collapse.

15. EARTHQUAKE
S