Multiple Choice
Identify the
letter of the choice that best completes the statement or answers the question.
|
|
|
1.
|
A lava flow with a
rough, blocky surface is a. | aa. | c. | agglomerate. | b. | tuff. | d. | pahoehoe. | | | | |
|
|
|
2.
|
A depression at
the summit of a volcano, caused by partial emptying of the magma chamber underneath, is
a a. | vesicle. | c. | caldera. | b. | crater. | d. | volcanic neck. | | | | |
|
|
|
3.
|
The main gas
erupted by volcanoes is a. | carbon dioxide. | c. | sulfur dioxide. | b. | chlorine. | d. | water vapor. | | | | |
|
|
|
4.
|
After the various
types of explosive eruptions, statistics suggest that the next greatest hazard for people living near
active volcanoes is generally a. | lava flows. | c. | toxic volcanic gases. | b. | tephra-rich mudflows. | d. | ash falls. | | | | |
|
|
|
5.
|
The vast majority
of volcanic eruptions occur a. | near boundaries. | c. | in oceans. | b. | in the middle of the plates. | d. | None of the above is correct. | | | | |
|