Name:                                                                           

 

 

GE2100 Environmental Geology - Final Exam, Spring 2005

 

 

Read each question carefully! There are 50 questions, each worth 2 points. For multiple choice questions, select the one best answer for each.

 

1. If you were standing on one side of a normal fault, the other side would be

a. moving to your right.

b. moving to your left.

c. either dropping or rising with respect to you.

d. definitely moving towards you.

 

2. At Montserrat, why must the volcanic risk maps be continually updated?

a. the types and levels of volcanic activity keep changing

b. the citizens tend to ignore the maps over time

c. each new eruption is given a different name

d. all of the above

 

3. Explosive volcanoes erupt violently because:

a. a low silica content makes the magma ÒstiffÓ.

b. pressure increases on the magma as it rises to the surface.

c. gases build up in the magma chamber and are released suddenly.

d. the magma temperature increases suddenly.

 

4. The one-hundred year floodplain refers to:

a. the area that would be water covered by a one-hundred-year flood

b. the area that would be 100% water covered every year

c. the peak height of the river during flood stage

d. the fine-grained sediments that have been building up for a hundred years

 

5. Direct measurements of atmospheric carbon dioxide

a. have been made since the 1950Õs.

b. demonstrate a consistent rise in concentration.

c. show seasonal changes, due to plant growth in the spring and decay in the fall.

d. all of the above

 

6. Deliberate flooding of the Grand Canyon was undertaken in early 1996 in order to

a. wash away all the excess sediment that had piled up since the Glen Canyon dam was built.

b. permit the generation of increased hydroelectric power from the Glen Canyon dam.

c. redistribute sediment and restore some beaches along the banks of the Colorado River.

d. all of the above

 

7. The most important greenhouse gas is:

a. carbon dioxide

b. water

c. sulfur dioxide

d. methane

 

8. Why did copper mining in this area eventually die out?

a. labor problems, higher costs of mining, and cheaper copper mined elsewhere

b. the mines ran out of copper

c. World war II ended

d. the copper was of poor quality

 

9. World oil reserves are expected to last roughly

a. another 10 years

b. another 100 years

c. another 1000 years

d. another 10,000 years

 

10. Global warming is likely to lead to

a. lower sea levels, because of increased evaporation.

b. increased severe storms, because of higher average atmospheric energy.

c. little observable climate change.

d. similar weather changes at both coastal regions and continental interiors.

 

11. The lower Mississippi River region, because of historical flood control measures,

a. is gaining coastal territory because of diverted river flow.

b. is gaining wetlands, because channelization deprives the region of nutrients and sediments.

c. has been causing cities like New Orleans to rise above the river level.

d. is at risk of greater flooding, because the natural mitigation systems have been damaged.

 

12. Pinatubo-sized volcanic eruptions occur, on average,

a. every year.

b. once every 10 years.

c. once every 100 years.

d. once every 1000 years.

 

13. The Modified Mercalli Index is used for

a. describing the volcanic energy release.

b. categorizing the intensity of earthquakes based on observations.

c. measuring flood-related damages.

d. measuring global-scale warming.

 

14. Which of the following statements best describes the current status of earthquake prediction and hazard reduction in the United States?

a. We know where potential fault zones are, but have no way to judge the hazards or monitor the fault zones.

b. The high-risk areas have been identified, and we have now learned to design Òearthquake-proofÓ buildings, so that structures in fault zones are known to be safe from major earthquakes.

c. We can predict major earthquakes very reliably, so evacuations are routinely undertaken when large quakes threaten.

d. We can forecast earthquake probabilities over periods of several years, but we cannot consistently predict the timing of major earthquakes.

 

15. The seismic-risk map of the United States is based on

a. frequency of occurrence of past earthquakes only.

b. severity of past earthquakes and anticipated ground motion in future ones.

c. a prediction of the likelihood of future earthquakes.

d. observation of precursor phenomena.

 

16. A pyroclastic flow is composed of

a. ash and steam.

b. a mixture of volcanic sediments and water.

c. hot, glowing particles of lava.

d. all of the above

 

17. A streamÕs average velocity is measured by a flow meter, and found to be 0.8 m/s. The channel dimensions are 6 m width, and 1.5 m average depth. The streamÕs discharge is:

a. 0.8 m3/s

b. 4.0 m3/s

c. 7.2 m3/s

d. 8.3 m3/s

 

18. Indicators of global climate change include

a. changes in sea level.

b. sizes of glaciers.

c. changes in the distribution and survival of plant and animal species.

d. all of the above

 

19. Why is the Quincy mine hoist oriented at a high angle towards the west?

a. So the sun can shine down the shaft, lighting it during the summer

b. Because the rock layers and copper mineral deposits are oriented that way.

c. Because it is safer to lower the miners at an angle

d. Because it takes less energy to remove the ore at an angle than from a vertical shaft

 

20. ÒPÓ waves

a. travel slower than S waves.

b. are created from compression and expansion generated by an earthquake.

c. are created from the shearing motion generated by an earthquake.

d. can only travel through both solid materials.

 

21. The location on the earthÕs surface, directly above the location of the first fault motion, is called the

a. epicenter.

b. focus.

c. fault scarp.

d. all of the above

 

22. The risk of flooding would be reduced by

a. rapid spring snowmelt.

b. very porous and permeable soil.

c. removing vegetation in the drainage basin outside the channel.

d. all of the above

 

23. A riverÕs hydrograph

a. shows the river velocity versus time.

b. shows the river discharge versus time.

c. shows the river flood crest versus time.

d. shows the river channel density versus time.

 

24. On the inside bank of a meander, where water flow slows,                             may be deposited.

a. a delta

b. an oxbow

c. a point bar

d. an alluvial fan

 

25. Satellites can be used to track and measure volcanic clouds because:

a. they can track clouds over long distances and for several weeks.

b. they can discriminate volcanic from meteorological clouds.

c. they can measure amounts of silicate ash and sulfur dioxide gas.

d. all of the above

 

26. A riverÕs floodplain serves as

a. a temporary storage area for excess water.

b. a mechanism for dissipating a riverÕs energy (momentum).

c. a repository for fine-grained sediments.

d. all of the above

 

27. Which of the following volcanoes is least likely to erupt violently and explosively?

a. Kilauea on Hawaii

b. Mount St. Helens in the Cascades

c. Mount Augustine in the Aleutians

d. Mt. Pinatubo in the Philippines

 

28. If you were building a home in an earthquake-prone region, how could you minimize seismic damage?

a. Build on a foundation of sand and gravel

b. Build on a foundation of compacted bay mud

c. Build on a foundation of old stream deposits

d. Build on a foundation of bedrock

 

29. The main purpose of Òhazard mitigationÓ is to

a. predict hazards before they occur.

b. prevent hazards from occurring.

c. provide legal assistance to hazard victims.

d. reduce the impacts of hazards on humans and infrastructure.

 

30. Earthquake energy, and damages, can be distributed unevenly because of

a. resonant frequencies of structures.

b. seismograph type.

c. vegetation.

d. all of the above

 

31. Which of these U.S. regions is not considered to be a future threat of volcanic activity?

a. the Cascade Range

b. the Aleutian Islands

c. the Ouachita Mountains

d. Yellowstone caldera

 

32. ColeÕs Creek has an average discharge rate of 0.4 m3/s. How much water flows out in one year?

a. 15,700,000 m3

b. 12,600,000 m3

c. 526,000 m3

d. 34,500 m3

 

33. Problems in projecting probable greenhouse-effect heating arise from uncertainty about

a. the effects of gases other than CO2.

b. projected global cloud cover as temperatures change

c. the relationship between CO2 produced, and resultant atmospheric CO2 levels

d. all of the above

 

34. Earthquakes and nuclear explosions can be discerned from seismographs because

a. nuclear explosions liquify the rock, and S waves wonÕt travel through them

b. nuclear explosions are much larger than earthquakes

c. only earthquakes occur with both shear and compression, producing both S and P waves

d. earthquakes produce mainly P waves, while nuclear explosions produce S and P waves

 

35. The principal source of rising levels of carbon dioxide in the atmosphere is

a. rising sea levels.

b. increased weathering of carbonate rocks.

c. increased volcanic activity.

d. burning of fossil fuels.

 

36. Large volcanic eruptions, such as Pinatubo in 1991, produce measurable global cooling for about

a. two weeks.

b. two months.

c. two years.

d. two decades.

 

37. Mt. Pinatubo erupted 20 million tonnes (metric tonne = 1000 kg) of sulfur dioxide gas into the stratosphere. This gas converts to sulfate aerosol at the approximate rate of a 30 day half-life. Calculate how much sulfur dioxide remained after 3 months (90 days).

a. 5 x 109 kg

b. 2.5 x 109 kg

c. 1.25 x 109 kg

d. 6.2 x 108 kg

 

38. Volcanic rocks are

a. crystallized from magma at or near the earthÕs surface.

b. by definition, only those produced by conelike volcanic structures.

c. coarse-grained, because the magmas typically spend so long inside the volcano before eruption.

d. all of the above.

 

39. The flow from the five largest rivers in the U.S.

a. peaks in the spring, due to snowmelt

b. peaks in the summer, due to hurricanes

c. peaks in the fall, due to rainy season

d. remains roughly constant throughout the year

 

40. Which is growing exponentially?

a. world population

b. atmospheric carbon dioxide

c. annual property damages due to natural disasters

d. all of the above

 

41. A riverÕs peak annual discharges are given below. Use the recurrence interval equation R = (N + 1)/M.

 

Year

Discharge (m3/s)

Year

Discharge (m3/s)

1992

1993

1994

1995

1996

1997

1998

1233

457

225

1075

851

354

202

1999

2000

2001

2002

2003

2004

2005

500

475

351

425

575

458

400

 

How many flows of 400 m3/s should occur during the next 30 years?                                                 

 

 

 

 

42. Name four important considerations when using the recurrence interval calculation.

 

a.                                                                                         

 

b.                                                                                        

 

c.                                                                                         

 

d.                                                                                        

 

43. Name four specific types of measurements scientists make to monitor a volcano.

 

 

 


44. Name four types of hazards generated by earthquakes.

 

              

 

 

 

45. Briefly explain how the ÒgreenhouseÓ effect works in the earthÕs atmosphere. Include the characteristics of solar and earth radiation.

 

 

 

 

 

 

 

 

 

46. Give four logical reasons why a watershedÕs flood hydrograph, following a rainstorm, would be sharp-peaked.

 

a.                                                                                                        

 

b.                                                                                                       

 

c.                                                                                                        

 

d.                                                                                                       

 

47. For a volcanic region, specify what information would be included on a risk map, versus what would be on a hazard map.

 

 

 

 

 

 

48. What environmental impacts did the copper mining have on this area?

 

 

 

 

 

 

49. What is the geologic rock type underlying your residence (MTU)? How do you know this?

 

 

 

 

 

50. If you were to drill a well into the rock beneath your home, would this be a good source of drinking water? Explain why or why not.