1. Announcements Exams are looking pretty good -- ridiculously close to a classic bell- shaped curve -- some A’s, more B’s, lots of C’s, fewer D’s, no F’s yet (I don’t think)… Today/Weds/after break we’ll do tsunami; I wouldn’t come to class on Friday if I were you…

2. TSUNAMI READ –p. 226 - 229 (up to “Variation along a Coastline”, including Case Study 8.1) –p. 235 - 240 (including Case Study 8.2 and the survivor story) –p. 242 (paragraph that begins with “Tsunamis…”) –p. 247-248 (section on tsunami) –p. 262 (“Adjustments to Tsunamis”)

3. TSUNAMI The volcano chapter was back-up for me talking about my field of expertise -- now we’re into things I know less about -- so count on quizzes/clicker Q’s to show you’ve read

4. Review (= clickers, of course)

5. Cerro Negro, an odd cinder(?) cone in Nicaragua, last erupted last in 1999. In 2004, there was active seismicity at Cerro Negro. Using what you know about cinder cones, would you say this one is dormant extinct active Cerro Negro, Nicaragua

6. My favorite dome erupted 110,000 years ago and 70,000 years ago. Using what you know about domes, would you say my dome is dormant extinct active (Mt. Elden -- not my favorite, but very cool, nonetheless)

7. The San Francisco Volcanic Field has been erupting for 8 million years, on and off. The most recent eruption was Sunset Crater, ~ 900 years ago. The SFVF is best characterized as… 1.dormant 2.extinct 3.active

8. context We learned from the 2004 Banda Aceh earthquake and tsunami that many parts of the world aren’t well prepared for tsunami. Things are radically better already in the SW Pacific We’ll look at a “first-world” country and see how they’re preparing, but first you need to know about tsunami in general

9. The science

10. To understand tsunami you have to understand waves… Sea or lake (“normal”) waves –velocity of wind –duration of wind –fetch (Read about wave sets and rogue waves in the text)

11. Wave terms 1.Crest/trough 2.L = wavelength 3.H = wave height 4.T = wave period 5.V = wavelength/ wave period 6.wave base = ~ 1/2 L

12. How “normal” waves work quack

14. Why do waves break?

15. Tsunami waves are different… WIND-GENERATEDTSUNAMI periods of 5-20 seconds periods of 10 minutes - 2 hours wavelengths of 10 - 200 meters wavelengths of 100 - 500 meters velocities of <50 km/h (= ~30 mph) velocities of >800 km/h (= ~500 mph) Tsunami waves don’t “break” as they near shore