chapter 6 quiz
The typical form for a composite volcano is a
steep-sided cone.
What event triggered the main eruption of May 1980?
A landslide removed rocks and released pressure on the magma.
Which of the following are ways that viscosity affects gases in magma?
Viscous magma prevents gas from escaping easily.
A volcanic eruption occurring beneath an ice sheet is likely to cause
a flood
The type of volcanic eruption shown in this photograph is
a pyroclastic column.
Some scientists think that Yellowstone could cause a future disaster because
all of these
Which of the following are true of felsic magmas?
all of these
Composite volcanoes are so called because they
are composed of lava flows, pyroclastic material, and mudflows.
If bubbles cannot escape easily from a magma, the resulting eruption is likely to:
be explosve
Continental mantle plumes that are composed of felsic magma tend to be explosive when the Earth's surface is reached. These explosive eruptions create:
calderas
The main cause of caldera collapse is
collapse of the roof of a magma chamber as magma erupts.
The most dangerous type of volcano is a
composite volcano
Which of the following plate boundaries is least likely to produce composite volcanoes?
continent-continent convergent boundary with a high mountain range (Himalayas)
When two plates are moving away from each other they are said to be:
diverging
Shield volcanoes commonly involve
fluid lava flows
When basaltic lava reach the ocean they
form pillow basalts.
Volcanic mudflows (lahars) are common on composite volcanoes because
large amounts of rain and snowmelt mix with loose ash on steep slopes.
Which of the following settings is most likely to have eruptions of basalt?
mid ocean ridge
What tectonic setting is interpreted to be the cause of volcanism at Yellowstone?
movement of North America over a mantle plume
When a volcano erodes and the solidified conduit is exposed, it is referred to as a volcanic:
neck
Shield volcanoes are built up primarily by relatively
nonxplosive outpourings of lava
These photographs show different types of eruptions. Drag the name of the eruption type to the correct photograph.
obvious
What type of basaltic feature is shown in this photograph? Black lava
pahoehoe lava flow
Rocks of the continental crust contain different minerals and each mineral has its own melting point. If the minerals with the lowest melting temperatures are the only ones melted, this is referred to as:
partial melting
Which of the following materials is NOT produced by erupting volcanoes?
sandstone
This volcano is relatively small and composed of volcanic cinders. What kind of volcano is it?
scoria cone
Volcanic domes grow from lava being injected into the interior of mounds of cooled lava and from the breaking out and moving down the flanks of
viscious lava flows
What type of basaltic feature is shown in this photograph?
volcanic bomb