Volcano Study Guide
Fill in the blanks using your book or class materials.
Section 4
1. A ______is a weak spot in the crust where molten
material, or ______, comes to the surface.
2. When magma reaches the surface, it is called ______.
3. Most volcanoes are found along ______.
4. One major volcanic belt is the ______, formed by the many volcanoes that rim the Pacific Ocean.
5. Volcanic belts form along the ______
______.
6. Volcanoes that form along converging boundaries create a string of islands called an ______.
7. A ______is an area where material from deep within the mantle ______and then ______, forming magma.
8. The Hawaiian Islands are an example of volcanoes forming over a ______.
Section 5
9. Inside a volcano, magma collects in a pocket called a ______.
10. The magma moves upward through a ______, a long tube in the ground that connects the magma chamber to Earth’s surface.
11. Molten rock and gas leave the volcano through an opening called a ______.
12. Many volcanoes have openings on the sides, called ______, where magma sometimes forces its way out.
13. A ______is the area covered by lava as it pours out of a vent.
14. A bowl-shaped area that may form at the top of a volcano around the central vent is a ______.
15. Dissolved ______are trapped in magma.
16. Volcanic eruptions can be classified as either ______or ______.
17. A volcano erupts quietly if its magma is low in ______. This means it has low ______and flows ______.
18. A volcano erupts explosively if its magma is high in ______making it ______and ______.
19. An explosive eruption breaks lava into fragments. The smallest pieces are volcanic ______.
20. A ______occurs during an explosive eruption when a mixture of hot gases, ash, cinders, and bombs are thrown out of the volcano.
21. There are three stages of a volcano’s activity:
a. ______-is erupting or shows signs that it may erupt
b. dormant- expect to ______and become active
c. ______-dead, unlikely to erupt again