Name ______________________________________________ Hour _______ Score ________/ 33 points
Volcanic Eruptions (7.3)
1. A type of rock called _________________________ is a very unusual looking rock
formed from lava. Each strand looks like spun glass.
2. TRUE or FALSE
Magma forms in the lithosphere.
If that statement was false, change the statement to be true by crossing out the incorrect part and writing in something to
make it true.
3. Circle the letter of each feature that ALL volcanoes share.
a. Pocket of magma beneath the surface
b. Crack to the surface
c. Side vents
d. Crater
4. Label the drawing with the
following terms: magma chamber,
pipe, vent, and crater
4 points
5. Lava flow is NOT necessarily hot
lava; it could be hundreds of years
old and currently be used as fertile
farm land. Define lava flow.
_____________________________
_____________________________
_____________________________
_____________________________
6. TRUE or FALSE
All volcanoes have at least one vent, but not all volcanoes will have a crater.
If that statement was false, change the statement to be true by crossing out the incorrect part and writing in something to
make it true.
7. The following phrases are the process of a volcanic eruption. Rewrite the phrases in order on the back.
gas bubble size increases greatly exerting enormous force
pressure from surrounding rock decreases
lava explodes out vent(s)
dissolved gases in magma expand & form bubbles
magma rises toward the surface
gases push magma from the chamber through the pipe
pressure falls within the magma
#7 Continued. Fit one phrase from the front on each blank below. (7 points – one for each line/phrase)
a. _______________________________________________________________________________________
b. _______________________________________________________________________________________
c. _______________________________________________________________________________________
d. _______________________________________________________________________________________
e. _______________________________________________________________________________________
f.
_______________________________________________________________________________________
g. _______________________________________________________________________________________
8. Geologists classify volcanic eruptions as ______________________ or ________________________. (2 points)
9. What factors determine the force of a volcanic eruption? (4 points) (HINT! Two of these are obvious from your book. The other
two were discussed in class. Use logical thinking after reading p. 212)
a. _____________________________________
c. _____________________________________
b. _____________________________________
d. _____________________________________
10. _____ volcanic ash
A. pebble-sized particles
11. _____ cinders
B. particles ranging from the size of a baseball to the size of a car
12. _____ bombs
C. fine rocky particles as small as a speck of dust
13. What is a pyroclastic flow? ________________________________________________________________________
______________________________________________________________________________________________
14. Use the Science & History timeline. (2 points)
a. Mount Pinatubo in the Philippines erupted QUIETLY / EXPLOSIVELY (circle one) in 1991.
b. Mount Etna in Sicily erupted QUIETLY / EXPLOSIVELY (circle one) in 2002.
15. Stages of Volcanic Activity (3 points)
a. _______________________ = unlikely to erupt ever again
b. _______________________ = erupting or showing signs that it will soon erupt
c. _______________________ = no longer active but may become active again anytime
16. Order the volcanic stages from least likely to erupt to most likely to erupt: 1 point
_______________________
_______________________
_______________________
17. Circle the letter of each sentence that is true about predicting volcanic eruptions.
a.
b.
c.
d.
Geologists are more successful in predicting volcanic eruptions than earthquakes.
There is never any warning when a volcano will erupt.
Geologists can predict how powerful a volcanic eruption will be.
Geologists cannot predict what type of eruption a volcano will produce.