Composite Volcanoes

Lesson 3: Volcanoes
One of the characteristics of a liquid is viscosity, or tendency
to not flow.
- Viscosity is principally dependent on the make-up and
temperature of the liquid.
- The shape of a mountain formed by volcanic eruptions depends
on several factors, such as the properties of the volcanic
material that comes out and the sequence and variety of
- Scientists classify volcanoes on the basis of shape and size.
- The three most common types of volcanoes are composite
volcanoes, shield volcanoes, and cinder cones
- Viscosity – the property of a liquid where its tendency is to
resist flow.
o Liquids with low viscosity tend to flow readily (example:
o Liquids with high viscosity flow slowly (example: honey)
- Composite Volcanoes- A steep volcanic cone built by lava flows
and eruptions. Ex. Mt. Rainier in Washington State.
- Crater- bowl shaped depression at the bottom of a volcano.
- Shield Volcanoes- volcano that forms from lava that builds up
slowly over time
- Cinder- pebble sized rock fragments that have the same
composition as ash. They are glassy and contain numerous
bubbles created by the gas that escaped as the magma
exploded into the air and then cooled quickly.
- Cinder Cones- The simplest type of volcano that forms from
congealed lava and rock fragments that have come out of a
single vent. As the gas-charged lava blows violently into the
air, it cools, turns into small fragments, and falls as cinders
around and downwind from the vent to form a steep circular or
oval cone.