1. ANNOUNCEMENTS Exams are getting there! Today: –a bit of review –controls on intensity –predicting (or not) earthquakes –the relation between depth and intensity Outlines are on the class website

2. Clickers, of course To be clear: click first, and when everyone has clicked, THEN please talk to your neighbor about why you answered the way you did, and why he/she should change his/her answer

3. The stadium at UC Berkeley has to have repairs done every 10 - 20 years. On a north-south line, seats, support columns, doors, etc. appear to get pulled apart over time so that in 10-20 years there are 3-4” (10 cm) gaps. What is the likely cause? 1.This is a good example of the “earthquake cycle” 2.A major earthquake occurs there every few years 3.Fault creep along the fault that goes underneath the stadium 4.This is a good example of a seismic gap

4. Where is the fault in this picture? 1 2 3 4

5. What is making the street curb creep? (if you get this wrong you are fired) 1.A left-lateral fault3. A reverse fault 2.A right-lateral fault4. A normal fault

6. Earthquake waves leave the focus and go out through the earth in all directions. Which of these is true? 1.S waves predict the existence of a liquid outer core 2.P waves predict the existence of a liquid inner core 3.The increased speed of S waves predicts the existence of the asthenosphere 4.S waves cannot move through the asthenosphere

7. INTENSITY Magnitude Distance from focus Geology! -- materials under buildings Ground motion 100 km (60 mi) from the epicenter destroyed virtually untouched

8. Foreshocks (or the earthquake itself?) Water wells Animals

9. Group project: depth vs intensity This project has two objectives –give you a good sense of how depth and intensity are related –have you understand this relation without having to listen to me lecture! And a minor third… –let those of you who swear you can’t do math see that you can interpret information from a simple graph!

10. In your group assign a… leader -- whip-cracker, you need to keep everyone on task and be sure everyone participates time keeper -- you need to keep track of the time reporter -- when it’s over, you stand up and tell the class what you found out note taker -- you get to make the graph and write the answers to the questions

11. In your group… Look at the worksheet: eqs, magnitude, depth, damage. We are using number dead/injured to describe intensity. Complete the graph and write 1-2-3 sentences to describe how those three parameters are related Answer the question about likely depth to the eq in China Answer the question about your landing site on planet Bling Put the four names of your group members on the graph/answer paper, with who did what job

12. Depth to earthqu a keDepth to earthqu a ke c a s u a l t i e s 0 50 100 150 200 250 300 350 400 450 500 none few-15 ~50 100s 1000s 10,000s 100,000s Number dead or injured: Intensity

13. Depth to earthqu a keDepth to earthqu a ke c a s u a l t i e s 0 50 100 150 200 250 300 350 400 450 500 none few-15 ~50 100s 1000s 10,000s 100,000s Number dead or injured: Intensity

14. Depth to earthqu a keDepth to earthqu a ke c a s u a l t i e s 0 50 100 150 200 250 300 350 400 450 500 Number dead or injured: Intensity none few-15 ~50 100s 1000s 10,000s 100,000s