Introduction to Earth Science

Introduction to Earth Science

Quiz 16 - Ocean Processes & Shorelines

1. It is currently estimated that 97.2% of water resources on Earth is in the world ocean. Most of the remainder is:
a. frozen in glaciers and ice caps.
b. trapped as groundwater and soil moisture.
c. stored in lakes, streams and reservoirs.
d. trapped as water vapor in the atmosphere.

2. Where does salt in seawater come from?
a. Salts are released the mechanical and chemical breakdown of rocks on land.
b. Salts in seawater comes from salts dissolved in streams and groundwater draining off of the continents.
c. Salts are released by hydrothermal vents on the seafloor.
d. Salts are concentrated in seawater through evaporation.
d. All choices are correct. 

3. Seawater is composed of water, dissolved matter (including solids and gas [as ions], and suspended matter (dust and organic residues). Of the ions in seawater (besides hydrogen and oxygen), the two most abundant elements are:
a. sodium and calcium
b. chlorine and sodium
c. calcium and sulphate (SO4)
d. magnesium and potassium

4. The salinity of seawater varies slightly from one part of the ocean to another, however, the average salinity of the oceans is about:
a. 4% (ppt).
b. 17‰ (ppt). 
c. 35‰ (ppt). 
d. 40‰ (ppt). 

5. Which of the relationships of temperature, salinity, and density of seawater is NOT true?
a. as temperature increases, density decreases.
b. as salinity increases, density increases.
c. as temperature changes, salinity remains the same.
d. as density increases, temperature increases.

6. A thermocline is a layer of water at the ocean surface that prevents the upwelling and mixing of cool nutrient-rich water to ocean surface waters, reducing the production of primary plankton (food) for marine life. What is the best description of thermoclines based on latitude?
a. Polar regions have well-developed thermoclines in winter months.
b. Temperate regions have strong thermoclines in the winter months.
c. Tropical region have no thermocline in winter months.
d. Temperate regions have weak thermoclines (moderate in summer, less in winter).

7. Because the Earth is rotating, this rotation causes an observable deflection in both the fluid atmosphere and oceans:
a. moving water is deflected to the right in the Northern Hemisphere.
b. moving water is deflected to the left in the Southern Hemisphere.
c. there is no Coriolis effect at the equator.
d. All choices are correct.

8. The Coriolis effect has an effect on surface water movement in the oceans called Ekman transport, causing seawater to be deflected and rotate with increasing depth (a process called the Ekman spiral). In most regions around the world where Ekman transport is observed, about at what is the depth that surface movement ceases?
a. 30 feet (10 meters)
b. 100 feet (33 meters)
c. 100 meters (330 feet)
d. 1,000 feet (330 meters) 

9. In large ocean basins, the Coriolis effect helps creates 5 large, circular ocean currents called:
a. gyres.
b. cyclones.
c. typhoons.
d. anticyclones. 

10. The current that flows along the East Coast of North America until it is deflected to the right by westerly winds is called the:
a. Gulf Stream.
b. North Atlantic Drift.
c. North Equatorial Current.
d. Florida Current.

11. Under what conditions does coastal upwelling commonly occur in coastal California?
a. Coastal upwelling only occurs where biotic productivity is high enough to sustain it.
b. Coastal upwelling only occurs on the eastern coasts of continents.
c. When a north wind blows south along the west-facing coastline and Ekman flow carries surface water away from shore.
d. When a south wind blows north along the west-facing coastline and Ekman flow carries surface water away from shore.

12. Based on historical data, how does El Niño conditions generally impact Southern California?
a. ocean water temperatures are higher (impacting sea life), and there is typically increased rainfall in the rainy season.
b. ocean water temperatures are lower (impacting sea life), and there is typically increased rainfall in the rainy season.
c. ocean water temperatures are higher (impacting sea life), and there is typically less rainfall in the rainy season.
d. ocean water temperatures are lower (impacting sea life), and there is typically less rainfall in the rainy season.

13. The time it takes for one full wave to pass a fixed position is called:
a. wave period.
b. wave height.
c. wave fetch.
d. wavelength.

14. The vertical distance between the trough of a wave and the crest of a wave is called:
a. wave height.
b. wave period.
c. fetch.
d. wavelength.

15. What determines wave speed in the open oceans?
a. wave period
b. wavelength
c. wind velocity
d. All of the choices are correct.

16. The region where storm winds blowing over the ocean surface generating waves is called a:
a. swell.
b. sea.
c. cyclone.
d. tsunami.

17. Groups of waves that move out of area where waves are generated by strong storm winds and travel long distances across ocean basins are called:
a. seas.
b. cyclones.
c. swells.
d. tsunamis.

18. As waves move along the surface of the water, what do water particles do?
a. They move back and forth in a direction parallel to wave motion.
b. They move back and forth in a direction perpendicular to wave motion.
c. They move along the crests of waves and can travel thousands of miles.
d. They oscillate in circles parallel to wave motion and whose diameters decrease with depth.

19. In deep water in the open ocean, how deep in water do surface waves cause particle motion?
a. about 1/2 of the wavelength of passing water waves
b. exactly twice the wave height
c. about twice the wavelength
d. about twice the wave period

20. What happens to waves when they reach shallow water?
a. They become waves of oscillation.
b. They slow down and become waves of transition.
c. They speed up.
d. They veer to the left.

21. Waves break when:
a. when the water depth (d) is about the same as the wave height (h).
b. where the water depth is about one half of its wavelength
c. the slope of the wave reaches a ratio of about 7:1 (7 long to 1 high).
d. all of the above.

22. What is surf?
a. Fully-developed waves generated by strong winds.
b. Waves moving out of the generating sea area.
c. Where waves steepen and build up near shore.
d. Waves moving into shallow water as turbulent front that moves onto the beach after they break.

23. The bending of waves so that they are more parallel to the shore is called:
a. diffraction.
b. reflection.
c. refraction.
d. translation.

24. How are longshore currents best described?
a. They involve movement of water perpendicular to the shoreline.
b. They involve movement of water toward the shoreline.
c. They involve movement of water parallel to the shoreline.
d. They involve movement of water away from the shoreline.

25. What is significant about longshore currents? 
a. Longshore currents are agents of erosion along shorelines.
b. Longshore currents are agents of deposition along shorelines.
c. Longshore currents move in directions dependent on the direction of the dominant incoming swell.
d. All choices are correct.

26. A strong current associated with the swift movement of water through inlets and the mouths of estuaries, embayments, and harbors is called a:
a. longshore drift.
b. longshore current.
c. rip current.
d. rip tide.

27. The force primarily responsible for tides is:
a. gravity.
b. friction.
c. the Coriolis effect.
d. wind pressure.

28. What is the relative tidal force of the Sun and Moon?
a. The Sun and Moon exert equal tidal forces on the Earth.
b. The Sun exerts about twice the tidal force of the Moon.
c. The Sun exerts three times the tidal force of the Moon.
d. The Moon exerts about twice the tidal force of the Sun.

29. When do Spring tides occur? 
a. during new moon & full moon phases.
b. during first quarter & third quarter phases.
c. In March and April in the northern hemisphere.
d. All choices are correct.

30. When the Moon is closest to the earth is called:
a. apogee.
b. perigee.
c. aphelion.
d. perihelion.

31. How many high tides occur almost every day in most coastal areas (including San Diego)?
a. 1.
b. 2.
c. 3.
d. 4.

32. When a tidal current flows out to sea as tide levels fall is called a:
a. ebb tide.
b. spring tide.
c. flood tide.
d. neap tide.

33. The intertidal zone is: 
a. the area between the high tide mark and dunes, a sea cliff, or permanent vegetation.
b. the area between the low and high tide marks.
c. a platform formed by depositional processes along the beach.
d. the area between the beach and a barrier island.

34. The zone that is the typically vegetation-free splash or spray zone above the high water line where back-beach dunes accumulate is called: 
a. the subtidal zone.
b. the intertidal zone.
c. the supratidal zone.
d. a wrackline.

35. The region on the East Coast (including the Delmarva Peninsula, Chesapeake Bay, and Delaware Bay) is what kind of Coast?
a. Ria coast
b. Deltaic coast
c. Glacial coast
d. Fault/tectonic coast
e. Volcanic coast

36. Which of the following is NOT a depositional coastal landform?
a. spit
b. baymouth bar
c. beach
d. sea arch

37. Barrier island beaches generally develop where:
a. The coast is composed of hard rock.
b. The nearby land has a rugged topography of hills and mountains.
c. The sea floor deepens rapidly offshore.
d. The sea floor remains shallow for a long distance offshore.

38. When observing a beach through yearly seasonal cycles, during stormy periods in winter with high wave energy:
a. there is a higher percentage of fine-grained sand on beaches.
b. more erosion occurs in bays than on headlands.
c. beaches are eroded and the sand moves to offshore bars.
d. offshore sand bars are eroded and beaches are built up.

39. An artificial barrier built at a right angle to the beach to trap sand that is moving parallel to the shore is known as a:
a. groin. 
b. stack.
c. seawall.
d. breakwater.

40. Construction of dams upstream on rivers flowing to the coast may lead to:
a. narrower beaches.
b. wider beaches.
c. the filling in of bays.
d. the building of a barrier island.