1. Chapter 20

2. 1. The dominant geologic processes in ocean basins are:
volcanism.
sedimentation.
weathering.
erosion.
both A and B.

3. 2. Which of the following does not effect wave height?
wind speed
depth of the water
length of time over which the wind blows
distance the wind travels over the water

4. 3. Waves only mix the upper part of the water column to a depth of:
4x wavelength.
2x wavelength.
equivalent to wavelength.
one-half wavelength.

5. 4. Longshore current is caused by:
river systems.
wave reflection.
wave refraction.
tidal processes.

6. 5. To avoid being carried out to sea in a rip current, a swimmer should:
swim toward shore.
swim parallel to shore.
swim away from shore.
Any of these will work.

7. 6. Tides result from:
the gravitational pull of the Moon and the Sun on the water of the oceans.
Earth’s magnetic field.
the rotation of Earth.
plate tectonics.

8. 7. Locally, tidal range is enhanced by:
distance to the Moon.
geographic barriers to water flow.
latitudinal position.
ocean temperature.

9. 8. Which time of year is peak hurricane season for the Gulf Coast?
June to November
January to March
August to October
June to October

10. 9. Which factors are required for hurricane formation?
warm sea surface temperatures
high humidity
light winds
All of these are required.

11. 10. Hurricanes form in the belt between 8 to 20 degrees latitude in both the northern and southern hemisphere, but not at the equator because:
water is too warm at the equator.
water is too cold at the equator.
winds are too weak at the equator.
winds are too strong at the equator.

12. 11. True or False: Computer models developed by meteorologists have accurately predicted hurricane paths and have saved many human lives.
True
False

13. 12. The best way to preserve a beach is to:
install seawalls.
install groins.
replenish sand from outside sources.
leave it alone.

14. 13. Based on the pattern of erosion and deposition along this beach, in which direction is the longshore current flowing?
toward the top of the image
toward the bottom of the image

15. 14. Coastal erosion is highest along tectonically ___ margins and lowest along ___ margins
active; passive
passive; passive
active; active
passive; active

16. 15. The east coast of North America is an example of a(n):
oceanic trench.
active continental margin.
fracture zone.
passive continental margin.

17. 16. Most of Earth’s oceans are an average of ____.
100 meters deep
1 km (1000 m) deep
3 km deep
5 km deep
10 km deep

18. 17. Where in the oceans would you expect to find oil?
abyssal plain
continental shelf
oceanic trenches
mid-ocean ridges
Oil is rarely found in the ocean.

19. 18. Most of the Pacific Ocean is surrounded by:
passive continental margin.
active continental margin.
continental rises.
broad continental shelves.
shield volcanoes.

20. 19. Ocean trenches are typically____.
1–2 km deep
3–5 km deep
8–10 km deep
10–15 km deep

21. Over time, a passive margin may become an active margin.
20. Based on what you know about continental margins, which of the following is most consistent with the evidence?
Over time, a passive margin may become an active margin.
Active margins have very little volcanic or tectonic activity.
The west coast of North America is an excellent example of a passive margin.
All of the above.
None of the above.