Study guide
Chapter 6 - Volcanoes Name __________________
1. What is the difference between lava and magma? _Lava is on the exterior of Earth and
magma is on the interior of Earth_ _____________________________
2. The three stages in the life of a volcanic mountain are active, dormant and extinct.
Define each of these stages: Active – currently erupting or capable of erupting at any
time, dormant- not currently erupting but still may erupt, extinct – will never erupt
again._________
3. How does the mineral silica affect a volcano’s eruptions? _Silica affects the stickiness of
the magma so it causes either quiet or explosive eruptions.______________________
4. What is a geyser? _A geyser is a fountain of water and steam that erupt from the
ground. ______
5. Name four landforms made by magma and describe each one. _volcanic necks – when
magma hardens in a volcanic pipe and the ground around it erodes away, a sill – when
magma forces itself through horizontal layers of rock, a dike – when magma forces itself
across layers of rock, and a batholith – when a large body of magma cools beneath
Earth’s surface.___________________
6. What are the three main types of volcanic mountains? __Shield volcanoes, Cinder cone
volcanoes, and composite volcanoes_How are they different from each other? __Shield
volcanoes are gently sloping, cinder cones are short but steep and composite volcanoes
are tall and sloping.__________________________________
7. What type of eruptions forms each of the volcanoes you named in #6? _Shield
volcanoes are formed entirely by lava and therefore only quiet eruptions, cinder cone
volcanoes are formed by ashes, cinders and bombs which means only explosive
eruptions while composite volcanoes are a little of each, explosive and quiet eruptions
and lava, cinders, bombs and ash.________________________
8. What is the difference between a crater and a caldera? __A crater is a bowl-shaped
area at the top of a volcanic mountain. A caldera is a huge hole left by a collapsed
volcanic mountain.______
9. What is an island arc? Name at least two island arcs. _An island arc is a string of
volcanic islands that are in one geographic area. Japan, New Zealand, Indonesia, the
Philippines, the Aleutians, and the Caribbean islands are all island arcs.____________
10. Name the parts of this volcano.
Ash cloud or gasses, or pyroclastic flow
Side vent
Lithosphere
crater
lava flow
pipe
magma chamber