2. What is a volcano?
Volcano is an opening
in the earth’s crust
where lava, pyroclasts
and gasses are ejected
onto the surface
during eruptions.
Mt. Mayon
Mt. Kilauea
Mt. Vesuvius
3. Parts of a Volcano
Cone- the most
prominent part of a
volcano
-formed by
the mountainous
accumulation of
volcanic materials
Mt. Mayon
4. Parts of a Volcano
Crater- a steeped-wall
*Caldera-a very large
depression at the peak of crater that can
the volcano and the
exceed for about 1
volcanic vent.
km in diameter; they
are formed when the
summit of the
volcano collapses
during violent or
explosive eruptions.
5. Lava vs. Magma
Magma are molten rocks found
beneath the earth’s surface.
Lava are molten rocks that flowed
out of the earth’s surface.
6. Kinds of Volcano according to
Shape and Composition
Cinder cone volcano- made up of
loose fragments called cinders
(pyroclasts and tephra)
-it is formed from
explosive eruption.
-it has a narrow base
and a steep slope
Examples: Sunset Crater in
Arizona, Mt. Pelee’ in the East
Indies
7. Kinds of Volcano according to
Shape and Composition
Shield cone volcano- has a
wide base with gently
sloping sides. It is made
up purely of solidified
lava.
Examples: Mauna Kea
and Kilauea Volcano in
Hawaii, Olympus Mons in
Mars
8. Kinds of Volcano according to
Shape and Composition
Composite Volcano- composed
of alternating layers of lava and
cinders. It is formed when
volcanic eruptions vary
between quiet and violent and
explosive.
Examples: Mt. Fuji in Japan, Mt.
Vesuvius and Mt. Stromboli in
Italy and Mt. Mayon in the
Philippines
9. Kinds of Volcano according to Activity
Active
Dormant/Inactive
Extinct
