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.
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
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.
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
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
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
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
a. another 10 years
b. another 100 years
c. another 1000 years
d. another 10,000 years
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.
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.
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.
a. epicenter.
b. focus.
c. fault scarp.
d. all of the above
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
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.
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
a. rising sea levels.
b. increased weathering of carbonate rocks.
c. increased volcanic activity.
d. burning of fossil fuels.
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
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
a. world population
b. atmospheric carbon dioxide
c. annual property damages due to natural disasters
d. all of the above
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.
45. Briefly explain how the ÒgreenhouseÓ effect works in the earthÕs atmosphere. Include the characteristics of solar and earth radiation.
a.
b.
c.
d.