7. When magma is expelled out of the volcano and reaches the
Earth’s surface, it is called lava.
A magma chamber is a large underground pool of molten
rock sitting underneath the Earth's crust.
8. A vent is the spot in the Earth’s crust where gases, molten rock,
lava, and rocks erupt.
A crater is a circular depression around a vent. This is where
the lava, ash, and rock erupt out of volcano.
A crater that becomes very wide as a result of the collapse of
its wall is called caldera.
MAIN FEATURES OF TYPICAL VOLCANO
9. TYPES OF VOLCANOES
Volcanoes may be classified according to their shape and activity.
VOLCANOES CLASSIFIED ACCORDING
TO SHAPE:
1. Cinder Cone Volcano
2. Shield Volcanoes
3. Composite Volcano
VOLCANOES CLASSIFIED ACCORDING
TO ACTIVITY:
1. Active Volcanoes
2. Dormant Volcanoes
3. Extinct Volcanoes
10. VOLCANOES CLASSIFIED ACCORDING TO SHAPE:
1. Cinder Cone Volcano
- are among the most common
volcanic landforms found in the world.
They are steep, conical hill formed
above a vent.
-are built from lava fragments called
cinders.
- rarely exceed 250 meters in height
and 500 meters in diameter.
Mount Paricutin
11. 2. Shield Volcano
- are larger than the cinder
volcanoes. They are formed
through the continuous flow
of lava that reach great
distances from central summit
vent or group of vents.
Mauna loa in Hawaii
12. 3. Composite Volcano
- also known as
stratovolcanoes.
- tall, symmetrically
shaped, and have steep sides,
sometimes rising 10,000 feet
high.
13. VOLCANOES CLASSIFIED ACCORDING TO ACTIVITY:
1. Active Volcano
- is said to be active if they have already erupted in the past or in
recent times and still capable of erupting any time.
The world’s smallest active volcano is in the Philippines. It is Taal
Volcano in Batangas. It is 508 meters or 1,660 feet high.
14. 2. Dormant Volcano
Volcanoes can be classified dormant if they have erupted in
historical times but are now quiet and inactive, but geologists think
that they still capable of erupting.
The world’s smallest inactive volcano is the Cuexcomate Volcano in
Puebla, Mexico. It is just 13 meters or 43 feet tall, with a reach or
diameter of 23 meters feet.
Cuexcomate is derived from Nahuatl Cuexcomate which means bowl
or place for keeping things.
15. 3. Extinct Volcano
Volcanoes are often considered to be extinct if there are no records of
their activity.
MOUNT APO