WorksheetsVOLCANIC ERUPTIONS!
Total questions: 12
Worksheet time: 7mins
Name
Class
Date
1.
The composition of magma determines its _____.
a)
viscosity
b)
darkness
c)
color
d)
none of the above
2.
As the temperature of lava increases, ________
a)
its viscosity decrease
b)
it begins to harden
c)
its viscosity increases
d)
it can flow a much short distance
3.
What is the term for a fluid's tendency to resist flow?
a)
Movement
b)
Silica
c)
Pressure
d)
Viscosity
4.
TRUE OR FALSE: A substance that flows quickly has high viscosity...
a)
True
b)
False
5.
Mafic Magmas have a normally __________ viscosity and _______ silica content with higher temperatures
a)
low, low
b)
low, high
c)
high, high
d)
high, low
6.
What factor(s) determine(s) whether an eruption will be explosive?
a)
The amount of gases in the magma
b)
The amount of silica in the magma
c)
The amount of gas and silica in the magma
d)
None of these affect the explosiveness of the volcano
7.
Very explosive volcanoes tend to have
a)
Low viscosity magma
b)
Gases rich in sulfur dioxide
c)
gentle, sloping sides
d)
High viscosity magma
8.
Basaltic lave flows are usually _________
a)
very fluid
b)
very viscous
9.
What provides the force that causes magma to erupt to the surface?
a)
the silica in the magma
b)
dissolved gases trapped in the magma
c)
gravity in the lithosphere
d)
the density of the magma
10.
Effusive volcanos generally have
a)
thick slow lava flows
b)
giant pyroclastic explosions
c)
runny lava flows
11.
Gases escape more readily out of
a)
low-silica content (basaltic) magma
b)
high-silica content magma
12.
Thick silica-rich magmas, in which gases DO NOT escape easily are characteristic of which type of volcano?
a)
Composite volcanos
b)
Shield volcanos
100 %
