EARTH 310 MIDTERM 1 EXAM -All Answers are Correct

1) The Theory of Plate Tectonics is . Select one: a. An educated guess b. The current best explanation c. A statement of fact d. Supported by research e. A and C f. B and D 2) The Theory of Plate Tectonics explains . Select one: a. Global distribution of volcanoes b. Global distribution of earthquakes c. Global distribution of mountain ranges d. All of the above 3) What type of tectonic plate boundary is the San Francisco Bay Area built on? Select one: a. Divergent b. Transform c. Convergent d. Transverse e. Subvergent 4) What type of fault are the San Andreas and Hayward faults? Select one: a. left-lateral strike-slip b. normal c. transform d. thrust e. right-lateral strike-slip 5) Hazards most associated with strike-slip earthquakes on the Hayward fault could include . Select one: a. Rain on snow b. Liquefaction c. Riptides d. Tsunamis e. All of the above 6) What is the main type of tectonic plate boundary that exists along the edge of the North American plate near the coast of Northern California, Oregon, and Washington? Select one: a. Convergent b. Divergent c. Compressional d. Transform 7) True or False? Megathrust earthquakes, like one that can occur on the Cascadia subduction zone off the coast of Oregon and Northern California (north of Mendocino California), can be strongest in magnitude—stronger than a San Andreas earthquake like 1906. Select one:a. False b. True 8) A major strike-slip earthquake on the San Andreas fault in California will cause a Thi scouarcteawsatsrdoowpnh loaidcedtbsyu10n00a0m084i97a64ff 05e8cfrtoimnCgourrseeHtosn 0o7-f26S-2a02n2 0F3:r5a1:n03cGiMscTo-0.0S0elect one: a. True b. False 9) The earth’s tectonic plates are always moving. We can measure their movements using GPS, just like we can track a car or a teenager with a cell phone. ;-) Given that the plates are always moving, why do we have only occasional earthquakes—rather than constant shifting and rumbling? Hint: this question is about elastic rebound theory! Select one: a. all of these b. None of these c. The lithosphere stretches to a limit, and then it breaks. d. The lithosphere can stretch like a rubber band. e. There is friction resisting the motion between any two tectonic plates. 10) Extra Credit Question: For those who lived in the Bay Area after the 1906 earthquake and before the 1989 Loma Prieta earthquake, it was a pretty quiet time—without many earthquakes at all. Leading up to the 1906 earthquake, however, there were numerous moderate magnitude earthquakes. Tom Brocher (see the video!) shows a timeline or “Bay Area Earthquake History” and discusses this pattern. Why were there so many earthquakes before the great 1906 earthquake and so few after? Many say the 1989 Lona Prieta earthquake marks the start of a new earthquake cluster for the Bay Area! Select one: a. The Bay Area was known as earthquake country before 1906. b. The earthquakes signified the movement of magma beneath the lithosphere. c. 1906 released all the accumulated tectonic stress from the lithosphere. d. Loma Prieta released all the accumulated tectonic stress from the lithosphere. 11)The Haywired scenario—headed by Tom Brocher and others—is a prepatory measure meant to ready law enforcement, fire fighters, utility workers, etc. for damage to infrastructure that will happen during a great Hayward earthquake. True or False? The Haywired scenario plans for a similar amount of shaking compared to the 1868 Hayward earthquake.Select one: a. True b. False12) True or False? The amount of damage due to the 1868 Hayward earthquake is equal to the consequences that we expect to witness following the upcoming next Hayward fault earthquake. Hint: Is the number of people and infrastructure built near the fault similar to that in 1868? Select one: a. True b. False 13) Areas where buildings are on landfill, for instance in the San Francisco financial and marina districts, are more prone to earthquake damage due to shaking than areas where buildings rest on bedrock. Hint: Tom shows photos and map of damage patterns in 1868. Select one: a. True b. False 14) How are builders in the Bay Area responding to prevent future earthquake damage? Select one: a. Building designs are now borrowed from structures in Kansas b. Concrete structures incorporate some internal metal bracing, typically pieces of rebar. c. Building designs use pistons to keep platforms under buildings level during earthquake shaking. d. Wood structures are safest because they flex. 15)Following the recent M6.0 Napa earthquake, geologists measured man made features (like roads and fences) that were intersected and offset (shifted) by the fault during the earthquake. Geologists noticed that for weeks and months after the earthquake, that the amount of offset recorded by these features gradually increased—so not all the right-lateral slip along the fault happened during the earthquake. Some occurred much later—and geologists call this afterslip. Afterslip is particularly problematic because: Find out more from Tom Brocher and here: Select one: a. It is movement following an earthquake that continues to break pipes, aqueducts and other infrastructure for weeks and months. b. It is movement during an earthquake that breaks pipes, aqueducts and other infrastructure.c. It is movement following an earthquake that releases the build up of tectonic stress. d. It is movement during an earthquake that adds to built up tectonic stress. 16) According to Tom Brocher and the US Geological Survey, what is the cumulative likelihood of a Bay Area earthquake larger or equal to a M6.7 by the year 2043? Select one: a. 6% b. 33% c. 22% d. 26% e. 16% f. 72% g. 8% 17)Based on fault trenching work, geologists can use broken soils (that geologists date ina lab using charcoal) to identify past earthquakes. What is the average duration between Hayward fault earthquakes indicated by these data? Select one: a. 220 years b. 150 years c. 160 years d. 100 years e. 140 years 18)Tom Brocher emphasizes that the strand of the San Andreas Fault in the area of Hayward, CA. is . Select one: a. locked b. inactive c. straining d. creeping e. elastic 19)How long could Bay Area residents be without drinking water due to an earthquake ona strike-slip fault of the San Andreas? Select one: a. Up to seven months b. Up to 2 months c. Up to one month d. Up to three months e. Up to nine months f. Up to 5 months 20)Which of the following hazards due to earthquake shaking should you be prepared for near the urban area of San Francisco and Oakland? Select one: a. Breaking and falling glass windows b. Crumbling and tumbling buildings and chimneys c. Gas leaks and fires due to broken gas linesd. Little to no water supply due to severed water pipes and aqueducts the bring water to the Bay Area e. All of these f. None of these 21)You live in the Berkeley Hills and are outside walking your dog. Abrupt strong earthquake shaking commences. Which is the best course of action? Select one: a. Stay outside where you are safest b. Avoid falling telephone poles and falling chimneys by climbing underneath a car c. Retreat and stand underneath the overhanging roof beside your house d. Avoid glass windows and overhanging parts of buildings, which could fall on you, and retreat indoors, where you can drop, cover, and hold on. 22)Earthquake warning systems will provide about 10-15 seconds of warning on average for Bay Area residents. The size of the time warning window depends on: Select one: a. The number of pets in the vicinity b. Magnitude of the earthquake c. Distance from the