This document discusses different types of volcanoes and volcanic landforms. It describes shield volcanoes as having quiet eruptions of fluid basaltic lava, forming broad domes like the Hawaiian Islands. Cinder cones erupt gas-rich basaltic magma and have short lifespans of weeks to years. Composite cones have characteristics of both shield and cinder cones and can produce pyroclastic flows moving at speeds over 100 mph. Calderas are large depressions caused by the collapse of a volcano's top after eruption, often forming lakes. The type of volcanic eruption depends on factors like magma composition, temperature, and dissolved gas content. Other volcanic landforms include necks, pipes,

1. Chapter 10 section 1
volcanoes and other igneous
activity

2. viscosity
• A measure of a
fluid’s
resistance to
flow.

3. Pyroclastic materials
• Wind will carry
small particles a
long way.
• The fragments
ejected during
eruption range in
size from very fine
dust and ash to
pieces that weigh
several tons.

4. volcano
• Anatomy of a volcano
–Activity often begins
when a fissure or crack
develops in the crust.
–A mountain formed of
lava and/or pryoclastic
material.

5. Shield volcanoes
• Are produced by the
accumulation of fluid
basaltic lava and
have quiet eruptions
• Shape of broad
slightly domed
• Most have grown
from the deep of the
ocean including the
Hawaiian Islands and
Iceland.

6. Cinder cones
• Ejects lava which
hardens in the air and
falls back down to form
the volcano.
• Produce gas rich
basaltic magma
• Short life span: Lasts
only a couple of weeks
to a couple of years and
then it never erupts
again.

7. Composite cones
• A combination of
Shield and Cinder
cone volcanoes
• Pyroclastic flows can
move down the
volcano at speeds up
to 100 mph.
• Lahars are mudflows
caused by melted
mountain ice and
snow mixed with lava
and mud.

8. Calderas
• A large depression
in a volcano caused
by the collapse of
the top of a volcano
after eruption.
• Many lakes form in
these depressions.

9. Volcanic necks and pipes

10. Lava plateaus
• Greatest volume of lava is excreted
from fissures
• Columbia plateau was formed this
way
• Numerous fissures erupted to form
this large landform.

11. Key Concept
• What determines the type of volcanic
eruption?
–The primary factors that determine
whether a volcano erupts violently or
quietly include magma composition,
magma temperature, and the amount of
dissolved gases in the magma.

12. Key Concept
• What other landforms are
associated with volcanic
eruptions?
–Neck, pipes, and calderas.