Exr5-Pinatubo Video - Lecture notes 5 PDF

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Exr5-Pinatubo Video - Lecture notes 5...

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E-GEO305, Exercise#5: NOVA video “In the Path of a Killer Volcano” Submit answers via the Answers form on Canvas Watch the NOVA video “In the Path of a Killer Volcano” about the USGS VDAP team’s experience predicting the 1991 eruption of Mt. Pinatubo, and answer the following questions. Proud Beaver fans will be happy to know that USGS-CVO scientist John Ewert (the youngest geologist of the bunch) got his degree from the OSU Geology Department. 1. Geologic studies in 1991 suggested that Mt. Pinatubo had erupted how many times in the recent past? (1 point) a. 3 times in the last 10,000 years b. 10 times in the last 500 years c. once in the last 1000 years d. 4 or 5 times in the last 2000 years 2. Why was a potential eruption of Mt. Pinatubo of such high concern? (1 pt) a. local villagers reported that historical eruptions were very violent b. eruptions usually caused large lava flows that would cover agricultural and forest lands c. about 10 million people lived in the surrounding area d. an eruption was likely to trigger a large tsunami 3. What critical observation finally led USGS and Filipino scientists to predict an impending major eruption and call for the evacuation of Clark Air Force Base? (2 pts) a. harmonic tremors suggested that the eruption would be a big one b. the composition of lava forming the growing dome in the crater was found to be the same as the thick pyroclastic deposits surrounding the volcano c. increased frequency of steam explosions d. small lava vents opened on the flanks of the volcano 4. What made the ash fall from Mt. Pinatubo especially destructive? (1 pt) a. unusually sharp ash fragments b. rain from a concurrent typhoon c. the long duration of the eruption d. the variable wind direction during the eruption 5. For months after the cataclysmic eruption, the primary geologic risk was from ____? (1 pt) a. seismic activity b. landslides c. pyroclastic flows d. lahars e. minor eruptions 6. What two factors led geologists to conclude that the activity at Mt. Pinatubo was magmatic, rather than something less threatening, such as tectonic activity or the volcano simply “letting off steam?” (4 pts)

7. Compare the eruption of Mt. Pinatubo and the 1980 eruption of Mt. St. Helens with respect to: a) eruption size, b) type of volcano, c) proximity to human population, and d) affects on U.S. military assets. (8 pts)

E-GEO305

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Exercise#5 Mt. Pinatubo video

8. The Mt. Pinatubo eruption injected ash into the atmosphere that circled the globe and had a global climate effect. How much did global temperatures drop, and for how long? (2 pts)

9. In the interest of improving the handling of a similar volcanic crisis in the future, what do you think the scientists could have done better? Explain your reasoning. (2 pts)

10. In the interest of improving the handling of a similar volcanic crisis in the future, what do you think the non-scientist public officials (in the video they were Clark AFB brass and local Filipino officials, but consider a more generic case if you like) could have done better? Explain your reasoning. (2 pts)

Now go to the Exercise#5 Answers form just below where you downloaded this from Canvas and fill in your answers. You can save your answers partway through and go back to them later if you like, just make sure you finish up and click the Submit button before the deadline. And be sure it then says that your assignment was successfully submitted.

E-GEO305

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Exercise#5 Mt. Pinatubo video...