ANNOUNCEMENTS

• First hour exam Wednesday 2/7; review session here, this evening, 2/5, 5.00 - 6.00, bring your questions

• Please pick up your homework on the table by the door

• When you send me an email (extra credit or otherwise) PLEASE be sure to let me know who you are!!

ANNOUNCEMENTS

• I STILL need PINs from: Boykin, Civetta, Dickason, Duvick, Escalante, Fix, Gonzalez, Huey, Hunt, Hurst, Jones, Krupoff, Magaldi, Mayon, Nelson, Rawls, Sillin, Slade, Watson

• Email me your PIN before the exam please

TODAY

• Some review (clickers, of course!)

• The earthquake “cycle” (elastic rebound)

• The relation between depth and intensity

Clickers please…

Who won the Super Bowl?

1. Chicago2. Indianapolis 3. Who cares???

On Dec. 26, 2004, a M 9.2 earthquake hit Sumatra, causing a devastating tsunami

that killed thousands of people. What was the magnitude here in Flagstaff?

1. 0, no one felt it or knew about it until some hours later

2. 3 - 4 -- an earthquake that big wasn’t so huge in Flag, but was still there

3. 9.2 -- magnitude doesn’t change from place to place

On Dec. 26, 2004, a M 9.2 earthquake hit Sumatra, causing a devastating tsunami

that killed thousands of people. What was the intensity here in Flagstaff?

1. 0, no one felt it or knew about it until some hours later

2. III - IV -- an earthquake that big wasn’t so huge in Flag, but was still there

3. IX -- intensity doesn’t change from place to place

If you got either of the last two wrong was because

1. You weren’t here last time and so missed the discussion of magnitude and intensity

2. You were here, but were daydreaming

3. You were here, but you’d appreciate hearing it again

Liquefaction…

1. Isn’t likely to occur here in Flagstaff

2. Happens when water and mud are shaken loose from each other

3. Can cause sand volcanoes

4. All of these are correct

A seismic gap that exists near San Francisco suggests that

1. there’s a gap in the danger zone along the fault near San Francisco because of the 1989 quake and all the aftershocks

2. a seismic gap suggest that no movement has occurred on the fault, and so seismologists think the motion on the fault could change to much more dip-slip than strike-slip

3. a type of imagery called seismic tomography lets scientists see where physical gaps between plates are, and there’s one near San Francisco

4. an earthquake is more likely to occur there in the near/intermediate future than around Loma Prieta, where the focus of the 1989 earthquake was

What is happening to the Nazca Plate beneath the Andes? -- what is its depth?

1. 50 - 350 km2. 0 - 700 km3. 75 - 200 km4. there’s no

way to tell

(Enough clickers for the moment…)

These are layers of rock

The “earthquake cycle”, usually called “elastic

rebound”

Exam reminders

• BRING a #2 pencil (for multiple-choice part)• Please be ready to take your baseball cap off

or turn it around• PLEASE be on time. The door will be

closed/locked at 11.45 so that people aren’t distracted by folks coming in/out. Use the bathroom before you start the mid-term.

• Please don’t ask for extra time. The exam ends at 12.20.

• Cell phones out and on the desk, closed too!

Exam reminders

• A lot of people find that the easiest way to do multiple choice is to cover the answers, and scribble a note down with the correct answer next to the question, and then see which answer is the closest