Chapter 9 Test Review

1. Chapter 9 Test Review Place these notes in your Notebook.

2. Iceland is one of the few places in the world where a mid-ocean ridge is above sea level.

3. Active volcanoes near convergent boundaries, such as those in the Andes Mountains of South America, would be expected to erupt explosively with abundant pyroclastic material. Pyroclastic material is made mostly of ash.

4. At a subduction boundary, a volcano is most likely to form on the overriding plate.

5. Crater lake is an example of a caldera type volcano.

6. Io Active volcanoes are known to exist on the moon, Mars, Earth, and even a moon of Jupiter called Io. Mount Olympus, Mars.

7. Pillow lava forms underwater.

8. Aa lava Pahoehoe lava

9. Chains of volcanic islands often form when one oceanic plate subducts beneath another oceanic plate.

10. Mount St. Helens and Crater Lake are located in the same mountain chain.

12. Lava plateaus are likely to have formed from magma that is basaltic with little gas content.

13. Mt. Fuji is a composite cone volcano. One advantage of monitoring volcanoes is that scientists can predict volcanic eruptions.

14. A shield cone has a broad base and gently sloping sides.

15. The lava erupting from Mauna Loa, an active volcano in Hawaii would most likely be erupting quietly with little pyroclastic material.

17. What would be a description of the type of magma found erupting from Mount Pinatubo in the Philippines? High gas content, with a high silica content.

18. Magma will not form on the Earth’s surface. It can only form deep below the surface. Lava is found on the surface.

19. The formation of magma depends on temperature, pressure, and water content. As silica content increases, magma tends to have greater viscosity. Magma tends to rise to the surface because it is less dense than surrounding materials.

20. Andesitic magma is associated with relatively explosive eruptions, but basaltic magma is associated with relatively nonexplosive eruptions.

21. The diagram below represents a chain of volcanic islands formed by the movement of a lithospheric plate over a hot spot. Identify which island is most likely to have an active volcano, which island is the oldest, and where a new island is likely to form in the future. (4 points) Island D will have an active volcano. Island A is the oldest. A new island is likely To form in Future at Point Y.

22. Essay 1: Cinder cone volcanoes are steep-sided and relatively small. Shield volcanoes are broad-based and very large. Explain where each is likely to form, and give reasons for the differences in shape and size. Cinder cones are small, steep-sided volcanoes. They form when molten lava ejected from a vent breaks, then drops & hardens into fragments. These fragments pile up in a cone shape around the vent. Cinder cones tend to form in groups or on the sides of larger volcanoes. Compared to cinder cones, shield volcanoes are very large. They form when basaltic lava erupts and flows long distances before hardening. Over time, layers of hardened lava build up into a broad-based, shield-shaped volcano.

23. Essay 2: Describe how a volcanic eruption can affect the lithosphere, the biosphere, the hydrosphere, and the atmosphere. A volcanic eruption affects the lithosphere by ejecting lava and pyroclastic materials that are part of the lithosphere. An eruption affects the atmosphere because it ejects gases into the atmosphere. An eruption affects the biosphere by altering the environment around the volcano.

24. A: Composite cone, B:Shield volcano, C: Cinder cone, D: Cinder cone, spatter cone.