Geology

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TheReallyBigOne_Questions.docx

Questions for “The Really Big One”

To answer questions on this article, refer to the article posted on Canvas or click on this link.

http://www.newyorker.com/magazine/2015/07/20/the-really-big-one

Due: See Canvas and upload onto Canvas by 11:59 pm.

Page numbers refer to the article in pdf format posted on Canvas. Figures and diagrams are presented below to help you visualize the concepts discussed in the article but do not provide specific answers to questions.

1) P 1-2. Explain how seismologists estimate the magnitude of an earthquake by using the length of time that the earthquake lasts. Approximately how long did the Japanese earthquake last?

2) P 3 “Every fault line has an upper limit to its potency.” What factors determine its potency and what is the San Andreas Fault’s upper limit?

3) P 3 Where is the Cascadia Subduction Zone, how long is it and what states does it run through?

4) P 3 What is a subduction zone? Describe what a tectonic plate is and how it relates to a subduction zone.

5) P 4 What two tectonic plates meet at the Cascadia Subduction Zone? What is the range in earthquake magnitudes that could occur in this zone and what is this range related to?

6) P4-5 After an earthquake in this region, explain what would likely occur next and why.

7) P 5 “Our operating assumption is that everything west of Interstate 5 will be toast.” How big is this area west of Interstate 5 is and what cities does it include?

8) P5 What are the odds that a big Cascadia earthquake will occur? Odds for a very big one?

9) P 6 What is the Ring of Fire (R0F)? What are most of the ROF earthquakes caused by? What are most of the ROF volcanoes caused by?

10) P 7-8 What was the specific evidence (seen and measured) in the “ghost forest” that indicated a very large Cascadia Subduction Zone earthquake in the past?

11) P 8 How did this historic earthquake affect Japan? What did the Japanese mean by the term “orphan tsunami.”

12) P 8-9 What specific details did Native Americans provide to support scientists’ evidence of a large historic earthquake around ~ 1700 a.d.?

13) P9 What deposits in the seafloor samples were scientists counting? How did these deposits originate?

14) P 9 What other aspects of the deposits were measured and what did all seafloor sample data tell scientists about the Cascadia Seismic Zone?

15) P 10 What is the Cascadia Recurrence Interval. Explain why this number is considered “dangerous” in terms of earthquake planning?

16) P 10 Make up an example using two sets of numbers to show how averages can be tricky. (See the example that is given in the article.) Using your example, explain why averages can be unreliable for earthquake prediction.

17) P 10 What is a compressional wave and what is a surface wave? How does each behave?

18) P 12 How do tsunamis compare to other natural disasters?

19) P 13-14 What are the hazards of moving water and what will an Oregon tsunami be like?

20) P 14 How long will it take to restore various services? Be specific for each service.

21) P 15 “The problem is bidirectional.” Explain what this statement means- what are the two directions and why is this a problem?

22) P 15-16 List and explain two specific safety issues that concern school superintendant Doug Dougherty.

Optional additional reading:

How to Stay Safe When the Big One Comes

http://www.newyorker.com/tech/elements/how-to-stay-safe-when-the-big-one-comes?