Guided Lab 4 - Sister Bannan PDF

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Sister Bannan...

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Instructions: Find the answers to the questions and write them on the lab. You will need to use the Internet to answer most of the questions. *** Submit your completed assignment in Canvas. PART I Volcanic Hazards in the Northwest U.S. You have been offered a job in Tacoma Washington. You are taking a tour of the area on a rainy afternoon. The rain clouds lift and you see a breath-taking cone-shaped mountain – Mt. Rainier. Your soon-to-be manager excitedly tells you that it is a great place to hike, camp, fish, ski, and mountain bike -- and it is located only 50 miles away. Sweet! The manager says that Mt. Rainier is a volcano, but assures you, “it has not erupted for a long time and there is no risk associated with it.” In fact, she has offered to sell you her home in nearby Orting, WA for what seems like a good price. You decide to check things out for yourself, and go to the Internet to search for hazards associated with Mt. Rainier, Washington. Here are questions you (and your professor) want answered. Use the USGS Mount Rainier Fact Sheet found in I-Learn, or this webpage: http://volcanoes.usgs.gov/volcanoes/mount_rainier/ According to the USGS, when did Mt. Rainier last have a significant eruption?

About a 1,000 years ago 1. If you look around at other sources you will find that there were reports of eruptions in the 19th century (1800s), but as experts have looked closely at these stories they seem to be coming to the conclusion that nothing that should really be called an eruption happened that recently. What people observed in the 19th century was most likely just steam venting, but even if there was some ash erupted, it was so small an amount that it left no evidence that survives into the 21st century. The fact sheet is a PDF file, if you don’t have Adobe Acrobat Reader on your computer, download it for free at http://get.adobe.com/reader/. A hazards map for the area around Mount Rainier is also found on the USGS Mount Rainier Fact Sheet. From the key for the map, what primary volcanic hazard exists in Orting, Washington where the manager has offered to sell the house?

Lahars 2. 3. Describe thoroughly what a lahar is, how one is formed, and why they are dangerous. Usually, Lahars form when some hot liquid (from a volcano or otherwise) travels down a steep slope and gains more volume. How often, according to the map key, do lahar events occur at Rainier (i.e. what is the shortest recurrence interval)?

Around 100 years 4. The summit area of Mt. Rainier is covered to a large extent by glacial ice. A small eruption of lava flows that reach less than 1 km from the summit could melt the glaciers ice. Briefly explain how this could cause a lahar that might threaten Orting.

The lava flow that flows close to the glacier could melt ice and cause water to flow and wear away on rock and soil creating a Lahar if there is enough build up.

5. Lahars typically travel 40 – 50 mph. Using Google Earth and the measuring tool, approximate the distance between the top of Mt. Rainier and Orting, along the river, in miles.

31.91miles 6. About how much time is there to evacuate Orting after a lahar starts down Mt. Rainier (in hours, use decimals)?

.8 hours 7. Look at Orting on Google Earth. How many rivers border the town of Orting (make sure you have the boundary of Orting visible)?

Two rivers 8.

How many bridges are there across the rivers where they border Orting (don’t go up or downstream beyond the borders of Orting)?

one 9. How would you evacuate your family away from the volcano and the rivers if you lived there? Describe a complete and practical plan. Remember, you and your family members are away from home for much of many days a week.

I would keep location on their phones and then tell them to try and get as far away as possible and after everyone is safe, create a rondevu to meet up at. 10. What is your acceptable risk for volcanic hazards? Would you live in Orting? Why or why not?

Nope, not unless I knew I’d be safe living there. Or the properties were really cheap. 11.

Part II “Dante's Peak” -- Fact or Fiction (Enjoy the movie, know the Science!) Instructions: • Read the attached fact sheet (at the end of the worksheet) about volcanic eruptions and volcanoes. • Watch the movie “Dante's Peak” looking for fact and fiction and for the answers to the questions that are on the next page. There are links to both the entire movie and excerpts in the Lesson in I-Learn. If you object to watching this PG-13 movie for any reason, contact your instructor for an alternative assignment. • When you notice in the movie a “volcano” fact correctly portrayed in the movie, write it in the left column of the table below. When you notice a fact that is incorrectly portrayed by exaggeration or an improbable event, write it in the column on the right.

In order to receive full credit you need at least 5 supported facts and 5 unsupported (exaggerated or improbable) facts. However, it’s more fun to write down all the facts that you catch – see how many you can get (below).

FACT VOLCANO FACTS SUPPORTED BY THE MOVIE

FICTION EXAGGERATED OR IMPROBABLE VOLCANO FACTS

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Seismology was used to predict the eruption Gas from the volcano killed wildlife Steam vents from the volcano SiO2 in the water supply The volcano created its own storm

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Physics of ash’s reactions on the human body were not incorporated in the movie (ie suffocation) The first eruption was much bigger than what most eruptions are initially The acidic nature of the water was played up in the movie and wouldn't have had as big of an effect on the boat The volcano hit without much warning which usually happen in that fashion

Dante’s Peak Questions 12. People were told to evacuate their town. Not all people listened to the geologist and some chose not to evacuate. Why do you think some people remained?

The city had been deemed desirable so people didn’t recognize the danger present.

13. Based on all the facts presented by the geologist (portrayed by Pierce Brosnan) in the town meeting, if you had been there, would you have listened and evacuated? Why or why not?

14. Does the movie stick to the facts for a typical stratovolcano? In your answer, consider the following:

a. Are there ash and pyroclastics present during the eruption? How are they depicted? b. Is the lava flow basalt or rhyolite? How can you tell? c. Is the pyroclastic flow basalt or rhyolite? Could both erupt at the same time?

15. List two realistic instruments and supporting data used to predict the eruption of the volcano.

16. There is an argument in the movie as to whether seismic activity beneath the volcano is tectonic or magmatic in origin. Is it possible to distinguish between the two? Support your answer. (see text or discussion of magmatic tremor at usgs.gov)

17. Compare the town of Dante’s Peak to Orting, WA. Discuss similarities and differences.

Part III 3rd Nephi and volcanoes. 1. Read 3 Nephi. List any signs that you see of volcanic eruptions being responsible for the destruction recorded in the scriptures.

After you read 3rd Nephi and have made your list, read the copy of the short news article below titled “Volcanic eruptions may have caused destruction.” It is from a 1999 LDS Church News. Discuss the news article with at least one other person (GREAT DATE!). In the yellow box below, write a paragraph about your discussion. If you are interested, also read the document “In the Thirty and Fourth Year: A Geologists View of the Destruction in 3rd Nephi” by Dr. Bart Kowallis....