EARS final exam. Type of natural disaster for which it is relevant (give the number indicated)

Transcription

1 EARS final exam Part I: Short answers 1. (10 points) For each of the following physical processes or concepts, give a type of natural disaster (e.g. hurricane, tsunami) for which it is an essential element. The first is done for you as an example. Effect or process Gravitational force Type of natural disaster for which it is relevant (give the number indicated) Landslides, snow avalanches Conservation of angular momentum 2 Release of latent heat and specific heat 2 Coriolis effect 1 Frictional force 1 Kinetic energy 1 Convection (vertical motion due to 2 contrasts in density) Decompression melting 1 2. I recently bought a new house in a new housing development in a rapidly growing suburb of St. Louis (Missouri), adjacent to the Mississippi River. Since I like to canoe and row, I chose a house with easy access to the river, about 1/4 mile away. I looked into the history of flooding, and I found that there are about 110 years of local data on Mississippi River discharge. From these data, it has been determined that my house is just above the level expected to flood in a 100-year flood. Since the last 100-year flood was only 7 years ago, I figure I m safe for at least the next few decades from flooding. a) (3 points) Is my thinking about flood hazard correct? Why or why not?

2 2. (continued) b) (4 points) Draw 2 hydrographs for equal-sized precipitation events, one representative of 100 years ago (when the area in which I live was completely undeveloped) the other representative of the present day (after extensive suburban development) 100 years ago present-day discharge discharge time since peak precipitation time since peak precipitation c) (4 points) In 4 sentences or less or identify 2 ways in which the hydrographs differ and identify the circumstances responsible for these differences.

3 d) (1 point) How will the recent suburban development near my house change the recurrence interval for flooding of a specified discharge (in comparison with the recurrence interval for a same-sized flood determined from the last 100 years of data)? Circle one. Increase Decrease Stay the same

4 3. The following sketch shows a map view of the Fairchild tectonic plate, which is bounded on all four sides by other plates. The line of volcanoes that includes A is on a different plate, towards which the Fairchild plate is converging. Other plates bounding the Fairchild plate are not shown. strike-slip plate boundary Z Y X D A subduction zone C spreading center B strike-slip plate boundary KEY continental hotspot volcanic island (active) } volcanic island (inactive) in undersea volcanic edifice (inactive) indication of relative plate motion continent a) (2 points) X, Y and Z represent earthquake epicenters. Of X, Y, and Z, which would most likely have the deepest hypocenter and which the shallowest? b) (4 points) What would be the most likely type of faulting (strike-slip, reverse, normal) for i) earthquake X? ii) earthquakes near volcano D?

5 3. (continued) c) (19 points) For the volcanoes found at A, B, C, and D, in the table below circle the most likely eruptive style and magma composition. Give an example of a place, somewhere in the world, where you would be likely to find a similar volcano. Finally, either specify the requested number of potential hazards (example: landslide), or write "none" if you think the environment is not particularly hazardous. (You can use a hazard more than once, as long as it is not for the same volcano). Volcano Eruptive style Magma composition (basaltic, rhyolitic, andesitic, or several types possible) A Explosive Basaltic Rhyolitic Not explosive Andesitic Several types possible Real location where a similar volcano can be found Likely hazards (list the number specified, or say "none") Give 3 B Explosive Not explosive Basaltic Rhyolitic Andesitic Several types possible Give 2 C Explosive Not explosive Basaltic Rhyolitic Andesitic Several types possible Give 1 D Explosive Basaltic Give 1

6 Not explosive Rhyolitic Andesitic Several types possible

7 4. (16 points) Many of the different hazardous events we have discussed can be quantified according to their magnitude. For 4 of the following types of hazards, answer the questions below. Earthquakes Volcanic eruptions Tornadoes Hurricanes Meteorite impacts a) Give the name of a magnitude scale that quantifies the hazard, or in some other way show that you are familiar with the magnitude scale. b) Indicate the range of the magnitude scale (e.g. maximum and minimum values, if they exist) c) List the most important criteria on which the scale is based.

8 5. (6 points) For this problem, assume the earth rotates in the opposite direction than it really does. In other words, assume it rotates on its axis from east to west, rather than from west to east, so the sun rises in the west and sets in the east. a) For the backwards-rotating earth, indicate with arrows the direction of circulation around the low pressure center of a hurricane sketched below, assuming the low is in either the northern or southern hemisphere of the earth. Northern Hemisphere L Southern Hemisphere L b) For the backwards-rotating earth, show on the map below the typical path a hurricane born at point A would travel during its lifetime.

9 c) Given the backwards-rotating earth, what part(s) of the continental United states would be most at risk for hurricanes? Explain your reasoning in 1 sentence.

10 Part II: Multiple choice (1 point each) 1. Accuracy is ; precision is. A. How close to the real value a measurement is; the exactness with which a number is specified. B. How close to the real value a measurement is; how carefully and slowly a measurement is taken. C. The exactness with which a number is specified; how close to the real value a measurement is. D. How well-calibrated the measuring device is; how close to the real value a measurement is. 2. Geologists' best estimate of the age of the earth is approximately A. 4.6 billion years B. 15 billion years C. About 6000 years D. 65 million years F. None of the above. 3. The half-life of a radioactive substance is A. Half of the time it takes a parent atom to decay to its daughter product B. The time for half of the parent atoms to decay to daughter atoms C. Half of the age of the rock or other object that contains the radioactive substance D. Either A or B E. None of the above 4. The geological time scale A. Was formulated when geologists first succeeded in using radioactive dating to determine the ages of fossils B. Includes periods such as the Cretaceous and Tertiary. C. Starts at the time of the first mammals and ends at the present day. D. Was developed by comparing the relative ages of strata containing certain fossil assemblages. E. B and D. F. A and B. G. B and C. H. None of the above.

11 5. Which of the following is correct? A. For a P-wave, the direction of particle motion and the direction of wave propagation are perpendicular to each other. B. S-waves travel faster than P-waves. C. Only S waves travel through the earth's outer core. D. P waves cause more damage to buildings than S waves or surface waves. E. All of the above. F. None of the above. 6. Of the following pairs of observations, which are both evidence supporting the theory of plate tectonics? A. The locations of earthquakes and the fit of the continents (the continental jigsaw puzzle ). B. The chemical composition of samples drilled from the mantle and the locations of earthquakes. C. The locations of volcanoes and the extinction of the dinosaurs. D. The pattern of magnetic anomalies on the ocean floor and the chemical composition of samples drilled from the mantle. E. All of the above F. None of the above 7. Brian Brady A. Invented the modern seismometer B. Predicted an earthquake in Peru that didn t happen. C. Was the first scientist to have his prediction evaluated by NEPEC (National Earthquake Prediction Evaluation Council) D. Was Marcia and Jan s stepdad E. B and C F. A and B G. None of the above 8. In seismology, the recurrence interval refers to: A. The number of times earthquakes of any magnitude occur in a certain time interval B. The number of times earthquakes of the same magnitude occur in a certain time interval C. The average number of earthquakes that occur in a certain time interval D. The average interval of time between earthquakes of the same magnitude E. The average interval of time between earthquakes of any magnitude

12 9. A phreatomagmatic eruption is A. Any eruption that is associated with stratovolcanoes B. An eruption in which magma comes in contact with water C. The most explosive type of volcanic eruption D. An eruption containing only basaltic magma E. B and C F. All of the above 10. Which type of natural disaster has the greatest frequency of occurrence and greatest expense for the US? A. Tsunamis B. Earthquakes C. Tornadoes D. Floods E. Volcanic eruptions 11. Which of these is not a possible effect of meteorite impact? A. Dust cloud suppresses photosynthesis B. Sulfur thrown into the atmosphere or chemical reactions with nitrogen in the atrmosphere cause acid rain C. Iridium and other heavy metals from the meteorite are globally dispersed; when they are deposited as dust on plants they poison animals feeding off the vegetation. D. Shock wave with energy equivalent to a magnitude 11 earthquake travels to all points of the earth. E. Large scale fires destroy vegetation F. The Coriolis effect is temporarily reversed G. C and F H. B and E I. E and F 12. Which of the following is not a type of meteorite? A. Icy B. Stony-iron C. Iridium D. Stony E. Iron-nickel F. A and C G. B and E H. A and D I. All are types of meteorites.

13 J. None is a type of meteorite. 13. Match the following definitions to the terms below (1 point for each correct match): An extremely powerful Pacific storm associated with circulation around low pressure. An extremely powerful Atlantic or Caribbean storm associated with circulation around low pressure. An extremely powerful Indian Ocean storm associated with circulation around low pressure. An extremely powerful storm in Kansas associated with circulation around low pressure. A. Cyclone B. Tornado C. Typhoon D. Hurricane E. Monsoon 14. Rain is associated with low-pressure systems because A. As air falls through the atmosphere at the center of the low, the increase in pressure causes water vapor to condense to water, which falls as rain. B. Rising air near the center of the low-pressure system expands and cools; the cooler air cannot contain as much water so water vapor condenses and falls as rain. C. The low pressure allows more water to evaporate from the ocean than would evaporate in a high pressure system. This evaporated water then condenses as rain. D. Rain clouds are pulled by gravity towards the center of the low pressure system, bringing rain with them. E. None of the above 15. Specific heat A. Is the energy needed to melt a unit mass of a substance. B. Is a very precise measurement of heat. C. Is the energy needed to raise the temperature of a unit mass of a substance by one degree. D. Depends on the relative humidity.

14 E. The amount of energy released by condensation of rain from moist rising air. F. All of the above. F. None of the above. 16. Why are there so many more impact craters visible on the Moon than on the Earth? A. The moon has been hit by many more meteorites than the Earth, particularly the > 1 km diameter bodies that create the biggest craters. B. The moon formed long before the earth formed, so has had more time to be hit by meteorites. C. The moon is made out of softer rock than the Earth that is more readily deformed when impacted by meteorites D. Because of gravitational effects, the moon deflects many of the meteorites that would otherwise hit the Earth E. Craters on the Earth are often destroyed by erosion and mountain-building processes, or obscured by vegetation or sedimentation. F. The period of heavy meteorite bombardment of the Earth occurred only when the planet was very young and entirely molten, so craters were not created. G. B and C H. C and D 17. Stromboli is an example of A. An earthquake-resistant Italian architecture style B. An erupting volcano in which the lava comes in contact with water C. The mildest kind of explosive volcano D. The most violent kind of explosive volcano E. A volcano where human intervention (bulldozing and blasting) succeeded in diverting lava from a village. F. A tasty Italian dish 18. Hurricanes and typhoons typically form (choose the right combination of items 1-8) 1. On the equator 6. Over cold oceans 2. At high latitude 7. In a previously calm area 3. At low latitude 8. In an area with a preexisting 4. In Kansas atmospheric disturbance 5. Over warm oceans A. 2 and 5 B. 4, 5, and 7 C. 1, 5, and 8

15 D. 3, 5, and 8 E. 3, 5, and 7 F. 5 and 8 G. 1, 6, and 8 H. 1, 5, and 7 I. 3 and How can seismologists tell a nuclear explosion from an earthquake? A. They go outside the seismic station and watch for radioactive fall-out. B. They look for differences in the relative amplitudes and frequencies of the P and S waves generated by nuclear explosions and earthquakes. C. They know that earthquakes generate both P-waves and S-waves but explosions generate only S-waves, so they look at the seismogram to see if P-waves are present. D. They determine the epicenter. If the seismic event is at a nuclear test site, then it is a nuclear explosion; if it is not, it is an earthquake. E. They determine the depth. If the seismic event is very shallow (< 200 m), it is a nuclear test; if it is deeper, it is an earthquake. F. None of the above. 20. Match each of the following terms to one of the definitions below: (1 point for each correct match) Asteroid Meteor Meteorite Comet A. A rocky body in space, smaller than a planet B. A 2001 model Ford C. Rocky body that impacts the solid Earth D. Icy body with a highly eccentric orbit E. A gaseous body with no regular orbit F. A satellite of the Earth G. Small body that vaporizes in the Earth s atmosphere due to the heat generated by the friction of its motion. 21. Where is the best place to be during a tornado? A. In a basement or cellar B. In a mobile home

16 C. In an open field D. In a tall building E. In Kansas F. Under a bridge 22. If a flood has a recurrence interval of 10 years, it means: A. That the flood will occur once every 10 years B. That the flood has a greater probability of occurring every tenth year than in the intervening years. C. That in any given year the flood has a 1/10 chance of occurring D. That the flood must be bigger than any other floods within any given 10 year period. E. None of the above. 23. What two factors are most important in controlling the explosivity of a volcano? A. Gas content and water content B. Location and water content C. Composition and gas content D. Water content and caldera size E. None of the above. 24. How long ago did the events at the Cretaceous-Tertiary (K-T) boundary occur? A. 65 years ago B. 65,000 years ago C. 6.5 million years ago D. 65 million years ago E. 650 million years ago F. 65 billion years ago 25. Which of the following evidence is consistent with both the hypothesis of a meteorite impact at the K-T boundary and the hypothesis of massive silicic volcanic eruptions? A. Large buried crater in the Yucatan formed in limestone deposits B. Anomalously high iridium concentrations in K-T boundary sediments C. The extinction of the dinosaurs and other groups of organisms. D. Carbon and soot in K-T boundary sediments around the world (from wildfires) E. Tektites and spherules F. Tsunami deposits G. C and F. H. A, C, and F.

17 I A and E. J. All of the above. K. None of the above. Extra credit (2 points) Of the types of natural disasters we have studied, specify one that has occurred in the last 2 weeks. Be specific---for example, just saying "earthquake" won't count. Question Max points 1 10 Score Multiple Choice Extra Credit 31 2 TOTAL