Earth Sciences 1 - Oceanography
Sample Mid-term Exam


PART I


Circle the correct answer. Multiple choice questions (2.5 pts each). Write name on each page.

1. Which of the following best describes the Pacific Ocean?

  1. A. shallowest ocean basin
  2. B. receives discharges of the largest rivers
  3. C. contains most of the world's trenches
  4. D. has very few islands
  5. E. little mountain building

2. Oceanic crust is _________________ than continental crust.

  1. A. more rigid
  2. B. less dense
  3. C. less rigid
  4. D. more dense

3. As you are passing 120žW longitude, you realize that it is your friend's birthday. It is 6 PM (Local Time) and you know that her home is at about 90žW longitude. What time is it at her home?

  1. A. 8 PM
  2. B. 8 AM
  3. C. 4 PM
  4. D. 6 PM
  5. E. 9 PM

 

 

4. Above is a diagram of plate tectonic features. By letter, identify the location of youngest crust.______

5. Above is a diagram of plate tectonic features. By letter, identify the location of a subduction zone.

6. Above is a diagram of plate tectonic features. By letter, identify the location of a passive margin.

7. How many lithospheric plates are shown in the diagram above?

8. Location of oldest ocean crust? _____

9. You are on a ship somewhere in the Indian Ocean, and your sextant shows that Polaris is 10 degrees above the horizon. What is 600 nautical miles from your location?

  1. A. Tropic of Cancer
  2. B. Tropic of Capricorn
  3. C. Prime Meridian
  4. D. Equator
  5. E. Arctic Circle

10. First hypothesized on evolution

  1. A. Forbes
  2. B. Maury
  3. C. Darwin
  4. D. Nelson
  5. E. Wilkes

11. ______________ was the first European to discover North America.

12. _____________ used the newly developed chronometer to map the Southern Ocean.

13. Pacific atolls are

  1. A. a piece of continent that broke off.
  2. B. formed by hot spots in the middle of plates.
  3. C. the tops of actively forming mountain chains at plate margins.
  4. D. formed by the build-up of volcanoes at mid-ocean ridges.
  5. E. formed at convergent margins.

14. Iceland was

  1. A. a piece of continent that broke away.
  2. B. a coral reef.
  3. C. the top of an actively forming mountain chain at a plate margin.
  4. D. being formed by the build up of a volcano at the mid-ocean ridge.

15. Continental blocks and their submerged margins constitute what percentage of the earth's surface?

  1. A. 29.2%
  2. B. 70.8%
  3. C. 40.6%
  4. D. 39.5%
  5. E. 23.1%

16. The average depth of the entire world ocean is about:

  1. A. 3800 meters
  2. B. 850 meters
  3. C. 2430 meters
  4. D. 300 meters
  5. E. 5000 meters

17. The shallowest parts of the major ocean basins are:

  1. A. mid-ocean ridges
  2. B. fracture zones
  3. C. trenches
  4. D. abyssal hills
  5.  

18. If a floating Ice-berg weighing 10,000 kg is in isostatic equilbrium, what is the mass of seawater displaced.

  1. A. 7500 kg
  2. B. 10000 kg
  3. C. 12000 kg
  4. D. none of the above

19. What is the volume of water displaced?

  1. A. 7500 cc
  2. B. 10,000 cc
  3. C. 10,000,000 cc
  4. D. none of the above

20. Plate tectonics is driven by

  1. A. rotation of the Earth
  2. B. the Earth's magnetic fields.
  3. C. mantle convection.
  4. D. evaporation at the mantle-crust interface.

21. The Atlantic Ocean's size is currently

  1. A. increasing
  2. B. decreasing
  3. C. remaining the same

22. A black smoker is

  1. A. a vent through which superheated water flows and reacts with sulfur bearing minerals
  2. B. a vent through which cool water flows and reacts with sulfer bearing minerals.
  3. C. a volcano that is completely under water.
  4. D. a volcano with >50% ash

23. Ocean basin rocks are most typically:

  1. A. basaltic rock
  2. B. thick accumulations of sedimentary rocks
  3. C. rocks having densities around 2.8 grams per cubic centimeter
  4. D. large volumes of granitic materials
  5. E. virtually no volcanic rocks

24. Mid-ocean ridges have high heat flows because

  1. A. of frequent earthquakes.
  2. B. of frequent volcanic activity.
  3. C. they mark plate boundaries.
  4. D. they are shallow parts of the ocean floor.

25. Most of the earth's deep earthquakes occur

  1. A. along mid-ocean ridges.
  2. B. in the center of plates.
  3. C. along subduction zones.
  4. D. in glaciated regions.

26. The absence of shear waves passing through the earth's outer core suggests that the outer core is:

  1. A. solid
  2. B. liquid
  3. C. brittle
  4. D. crystalline

27. The earth's core consists primarily of:

  1. A. iron-nickel
  2. B. basalt
  3. C. magnesium-rich rocks
  4. D. aluminum-rich rocks

28. T F Calcium carbonate sediments are commonly found in the deepest parts of the ocean basins.

29. Which of these deposits would you expect to find on the Antarctic continental shelf?

  1. A. foraminifera rich sediments
  2. B. fine grain mud
  3. C. manganese nodules
  4. D. poorly sorted, coarse grained sediments

30. Where did a 10 km piece of cosmogenic material strike the earth over 60 million years ago.

  1. A. Northern Canada
  2. B. Red Sea
  3. C. Gulf of Mexico
  4. D. China Sea
  5.  

 

31. On the map above, how old is the reversed area designated "B"?

  1. A. 0.5 million years old
  2. B. 2 million years old
  3. C. 4 million years old
  4. D. 8 million years old
  5. E. 16 million years old

32. Using the map above, determine the half-rate of sea-floor spreading as

you did for the different ocean basins in lab.

  1. A. 250 km/million years
  2. B. 20 km/million years
  3. C. 2 km/million years
  4. D. 0.2 km/million years
  5. E. 0.02 km/million years

 

Essay Questions:

 

33. What are 3 main kinds of marine sediments. What is the source of each. (10 pts)

34. Describe how and where earthquakes occur. Give 3 specific examples. A diagram may help (10 pts).

 
PART II

1. There are 1000 grams of Kryptonite dissolved in all the world's oceans. It is removed at the rate of 100 grams/year. What is the residence time?

  1. A. 0.1 year
  2. B. 1 year
  3. C. 10 years
  4. D. 100 years
  5. E. 1000 years

2. How does the concentration of CO2 dissolved in sea water vary with depth?

  1. A. does not change with depth
  2. B. high in the photic zone (surface mixed layer) due to biotic processes; decreases with depth
  3. C. low in the photic zone (surface mixed layer) due to biotic processes; increases with depth
  4. D. decreases with depth in gyres, constant everywhere else

3. The calorie is the amount of heat required to

  1. A. raise 1 kg of liquid water 1 degree Celsius
  2. B. raise 1 pound of liquid water 1 degree Farenheit
  3. C. raise 1 gram of liquid water 1 degree Celsius.
  4. D. raise 1 kg of liquid water 1 degree Farenheit.

4. T F Satellites can be used to estimate the amount of plankton in the ocean by the color of the water.

5. After hydrogen and oxygen, what is the most abundant element in seawater

  1. A. nitrogen
  2. B. carbon
  3. C. chloride
  4. D. calcium

6. Which of the following elements behaves conservatively, or in other words, is relatively unreactive in seawater and has a long residence time.

  1. A. calcium
  2. B. phosphorus
  3. C. oxygen
  4. D. sodium

7. In water, hydrogen and oxygen atoms are held together by

  1. A. a hydrogen bond
  2. B. a covalent bond
  3. C. surface tension
  4. D. cohesion

8. Water is an excellent solvent because it

  1. A. has a covalent bond
  2. B. has a high heat capacity
  3. C. has a low pH
  4. D. is a dipolar molecule

9. Which of the following combinations of temperature and salinity would

result in the highest density?

  1. A. T = 0°C, S = 25ä
  2. B. T = 0°C, S = 35ä
  3. C. T = 10°C, S = 35ä
  4. D. T = 10°C, S = 25ä

10. How many calories of heat energy must be absorbed to melt 2 grams of ice (at O°C)?

  1. A. 40
  2. B. 80
  3. C. 160
  4. D. 540

11. The _____________ of water is lowered with addition of salt

  1. A. freezing point
  2. B. boiling point
  3. C. density
  4. D. all of the above

12. T F A cation has a positive charge

13. Which of the following will increase the solubility of a gas in seawater?

  1. A. increasing temperature
  2. B. increasing salinity
  3. C. increasing pressure
  4. D. none of the above

14. T F The oceans contain more dissolved carbon than exists in all the land plants, animals, fossil fuel reserves, and atmosphere combined.

15. Seasons are caused by:

  1. A. the variation of the distance between the earth and sun
  2. B. the tilt of the earth's axis of rotation
  3. C. the revolution of the earth about its axis
  4. D. the increase in the earth's velocity as it approaches the sun

16. Maximum incoming solar radiation in northern mid-latitudes occurs on about:

  1. A. September 21
  2. B. July 4
  3. C. June 21
  4. D. August 21

17. Most of the energy radiated from the earth's surface is in the form of:

  1. A. energy from radioactive decay
  2. B. infrared radiation
  3. C. ultraviolet radiation
  4. D. visible light

18. When air rises, the rate of cooling of the air with increasing altitude decreases when condensation begins because:

  1. A. condensation requires energy
  2. B. rising air expands
  3. C. clouds formed reduce the amount of insolation
  4. D. condensation gives off energy

19. In the figure below, which is the correct representation of surface wind patterns on earth?

<pic>

20. The temperature on Earth is moderated by the high___________ of water.

  1. A. vapor pressure
  2. B. specific gravity
  3. C. sensible heat
  4. D. heat capacity

21. The average density of seawater is __________ g/cubic centimeter.

  1. A. 1.0
  2. B. 1.028
  3. C. 1.28
  4. D. 2.80

22. In reference to the pycnocline, which of the following is correct?

  1. A. salinity changes dominate
  2. B. comprises 80% of the ocean water
  3. C. water density increases with depth
  4. D. large seasonal variation in conditions occur
  5. E. water density is constant with depth

23. Which of the following wavelengths of the incoming solar radiation is

absorbed primarily in the uppermost meter of sea water?

  1. A. blue
  2. B. red
  3. C. green
  4. D. ultra violet

24. The most important process removing heat from the ocean surface is:

  1. A. evaporation of water
  2. B. warming atmosphere by conduction
  3. C. back radiation to space
  4. D. ocean currents
  5. E. growth and decay of organisms

25. Geostrophic currents result from:

  1. A. balance between winds and the Coriolis effect
  2. B. balance between gravity and the Coriolis effect
  3. C. balance between temperature and salinity
  4. D. balance between density and the Coriolis effect

 26.  The upper sunlit layer of the ocean is called the ___________  and extends to a depth of about ____________.


Essay Questions (10 pts each


34. There are 100,000 KILOGRAMS of element X dissolved in all the world's oceans.  It is added to the ocean at the rate of 10,000 GRAMS/year. What is the residence time of element X? Show work.

35. Discuss the ATOC experiment in terms of its

a) goals (3 pts);

b) scientific principles involved (5 pts), and

c) the arguments presented against conducting the experiment (2 pts).

 

36. Surface water is set in motion through wind stress.

a) List or describe the secondary forces that act on water once it is in motion (2 pts).

b) Describe how and where winds can create upwelling of deeper waters (5pts)?

c) Why does the upwelling increase biological productivity (3 pts).

 

Return to the Earth Sciences 1 Exams Page