Tired of watching MTV? Why not take this short quiz to test your knowledge of the concepts covered in Chapter 4 of your text?

1			Mt. St. Helens: Need a Hint?
			A)	last major eruption was in 1980.
			B)	is part of the Cascade Range
			C)	is located in southern Washington
			D)	all of these
2			Volcanic eruptions can affect climate because: Need a Hint?
			A)	they heat the atmosphere
			B)	volcanic dust and gas in the upper atmosphere reflects and absorbs solar radiation
			C)	I told you so in class
			D)	volcanoes have no effect on Earth's climate
3			Magma extruded at high temperatures tends to be: Need a Hint?
			A)	very fluid
			B)	very viscous
			C)	very explosive
			D)	very unwelcome at a party
4			Magma with a high silica content tends to be: Need a Hint?
			A)	very hot
			B)	very smelly
			C)	very viscous
			D)	also very unwelcome at a party.
5			Magma with a large amount of dissolved gases tends to be: Need a Hint?
			A)	very viscous
			B)	very explosive
			C)	very messy
			D)	really truly very unwelcome at a party
6			Magma is: Need a Hint?
			A)	melted rock
			B)	the source of all igneous rocks
			C)	the reason volcanoes form
			D)	all of these
7			Which of the following does not affect the viscosity of magma? Need a Hint?
			A)	silica content
			B)	temperature
			C)	amount of gases
			D)	all of these affect the viscosity of a magma.
8			Which of these is not a common gas in magma? Need a Hint?
			A)	water vapor
			B)	carbon dioxide
			C)	sulfur dioxide
			D)	methane
9			The asthenosphere is: Need a Hint?
			A)	the source of most magmas.
			B)	completely molten.
			C)	heated by the presence of magma.
			D)	all of these.
10			Submarine eruptions of volcanoes: Need a Hint?
			A)	cannot occur because water causes magma to solidify too quickly
			B)	form pillow basalts
			C)	have never been observed
			D)	none of these
11			The greatest single volcanic eruption that geologists have documented is: Need a Hint?
			A)	Toba, Indonesia
			B)	Krakatau, Indonesia
			C)	Tambora, Indonesia
			D)	Agung, Indonesia
12			A typical example of a shield volcano is: Need a Hint?
			A)	Mt. St. Helens
			B)	Hawaii
			C)	Mt. Ranier
			D)	Mt Pinatubo
13			Which type of volcano is not commonly composed of basalt? Need a Hint?
			A)	shield volcano
			B)	spatter cone
			C)	cinder cone
			D)	composite volcano
14			An igneous rock made of pyroclasts has a texture called: Need a Hint?
			A)	fragmental
			B)	porphyritic
			C)	vesicular
			D)	fine-grained
15			The largest known volcano is: Need a Hint?
			A)	Mt. Ranier
			B)	Hawaii
			C)	Olympus Mons (Mars)
			D)	Iceland
16			Crater Lake in Oregon is an example of: Need a Hint?
			A)	a shield volcano
			B)	a caldera
			C)	a cinder cone
			D)	a volcanic bomb
17			Mafic igneous rocks contain: Need a Hint?
			A)	about 50% silica
			B)	about 60% silica
			C)	about 70% silica
			D)	about 80% silica
18			Obsidian is an igneous rock that Need a Hint?
			A)	solidified very rapidly to form glass.
			B)	solidified very slowly to form pegmatite
			C)	solidified beneath Earth's surface
			D)	solidified in Earth's mantle
19			The most common type of volcano in the "Ring of Fire" is: Need a Hint?
			A)	a composite volcano
			B)	a shield volcano
			C)	a cinder cone
			D)	a volcanic fissure
20			Which planet is not known to have volcanoes? Need a Hint?
			A)	Venus
			B)	Earth
			C)	Mars
			D)	Saturn