X-rays from a Central “Exhaust Vent” of the Galactic Center Chimney
activities volcanoes.docx
1. Lesson 8.3: True or False
Name___________________ Class______________ Date________
Write true if the statement is true or false if the statement is false.
_____ 1. Many composite volcanoes are found in the Pacific Ring of Fire.
_____ 2. All volcanoes release ashes, gases, and pyroclasts.
_____ 3. Composite volcanoes have steep sides because the lava cannot flow very far.
_____ 4. Mauna Loa in Hawaii is an example of a composite volcano.
_____ 5. A shield volcano has a flatter top than a composite volcano.
_____ 6. Cinder cones have gently sloping sides like shield volcanoes.
_____ 7. Most large volcanoes have nearby cinder cones.
_____ 8. Cinder cones usually build up very rapidly.
_____ 9. Cinder cones always erupt over a long period of time.
_____ 10. The largest supervolcano in North America is Yellowstone.
Lesson 8.3: Critical Reading
Name___________________ Class______________ Date________
Read this passage based on the text and answer the questions that follow.
Composite and Shield Volcanoes
Composite volcanoes have broad bases and steep sides. These volcanoes usually
have a large crater at the top. The crater was created during the volcano's last eruption.
Composite volcanoes are formed by alternating layers of magma and ash. The magma
that creates composite volcanoes tends to be thick. Steep sides form because the lava
cannot flow very far from the vent. The thick magma generally creates explosive
eruptions. Ash and pyroclasts fly up into the air. Much of this material falls back down
near the vent. This contributes to the steep sides of composite volcanoes. Composite
volcanoes are common along convergent plate boundaries. When a tectonic plate
subducts, it melts. This creates the thick magma needed to produce this type of
volcano.
2. Shield volcanoes have a very wide base and a flatter top than composite volcanoes.
The magma that creates shield volcanoes is relatively thin. Thin lava spreads out and
builds up, layer by layer. Shield volcanoes tend to be very large. For example, the
Mauna Loa shield volcano in Hawaii has a diameter of more than 112 kilometers (70
miles). Shield volcanoes often form along divergent plate boundaries. Because of their
thin magma, shield volcano eruptions are non-explosive.
Questions
1. Contrast the shape and composition of composite and shield volcanoes.
2. Describe where and how composite volcanoes form.
3. Outline the formation of shield volcanoes.
Lesson 8.3: Multiple Choice
Name___________________ Class______________ Date________
Circle the letter of the correct choice.
1. Composite and shield volcanoes differ in their
a. thickness of magma.
b. overall shape.
c. type of eruptions.
d. all of the above
2. Composite volcanoes are common at
a. divergent plate boundaries.
b. subduction zones.
c. mid-ocean ridges.
d. hot spots.
3. Composite volcanoes are also called
a. cone volcanoes.
b. stratovolcanoes.
c. cinder volcanoes.
d. convergent volcanoes.
3. 4. A shield volcano
a. consists of layers of lava.
b. is relatively small.
c. has very thick lava.
d. two of the above
5. A caldera forms when a
a. vent is plugged by magma.
b. magma chamber collapses.
c. crater fills with water.
d. lava field hardens.
6. Cinder cones are composed mainly of
a. rock fragments.
b. thin lava.
c. magma.
d. ashes.
7. A supervolcano
a. is the most dangerous type of volcano.
b. may cause Earth’s temperature to rise.
c. has no magma chamber.
d. produces no ash.
Lesson 8.3: Matching
Name___________________ Class______________ Date________
Match each definition with the correct term.
Definitions
_____ 1. large, bowl-shaped depression that forms at the top of some volcanoes
_____ 2. smallest and most common type of volcano
4. _____ 3. example of a shield volcano
_____ 4. volcano with a broad base and steep sides
_____ 5. example of a composite volcano
_____ 6. volcano that produces so much ash that it blocks the sun
_____ 7. volcano that forms a huge, gently sloping mountain
Terms
a. caldera
b. cinder cone
c. composite volcano
d. shield volcano
e. supervolcano
f. Kilauea
g. Fuji
Lesson 8.3: Fill in the Blank
Name___________________ Class______________ Date________
Fill in the blank with the appropriate term.
1. A volcano formed of alternating layers of magma and ash is a(n) __________
volcano.
2. __________ volcanoes form from thick lava.
3. Composite volcanoes generally have __________ eruptions.
4. __________ volcanoes form from thin lava.
5. Shield volcanoes generally form along __________ plate boundaries.
6. Shield volcanoes generally have __________ eruptions.
7. Cinder cones usually have a(n) __________ at the summit.
5. Lesson 8.3: Critical Writing
Name___________________ Class______________ Date________
Thoroughly answer the question below. Use appropriate academic vocabulary and clear
and complete sentences.
What is a supervolcano? How can a supervolcano cause a volcanic winter?