1. Active and Neotectonic Structures 1) What's the difference
Active and Neotectonic Structures 1) What's the difference? 2) Methods in active tectonics 3) Methods in neotectonics 4) Implications for structural geology 5) Consequences for Society

2. Time scales
Tectonics- study of large scale deformations and Earth evolution processes at scales of millions to tens of millions of years; focus of this class
Neotectonics = thousand to tens of thousand years
Active tectonics = happens during a person's lifetime

3. Present is key to the past
Uniformitarianism
Present is key to the past
Or is it?

4. Methods in Active tectonics
1) Seismology
2) Measuring recent movements
Surveying
GPS techniques
Radar interferometry

5. Earthquakes occur all the time- all over the world
They produce ground motion (seismic waves), that we can measure

6. >3000 seismological observatories around the world, continuously recording seismic waves

11. How long did it take seismic waves to travel from Alaska to Tucson?

12. Real-time action; Real-time measurement-
what can we learn from seismology about structural geology??
1) Location and depth of faulting (brittle-ductile transition)
2) fault plane solutions- orientation of fault and sense of slip- geometry and kinematics
3) Energy release- size of fault, rupture characteristics- unidirectional, bidirectional, chaotic?

13. Seismic hazard
Bad: destruction of property
and life
Good? Funding for geology?

14. What do we need to know, in order to predict earthquakes??

15. (1) aseismic movements that occur in between earthquakes

17. The wave of the future-GPS
Global Positioning System
Satellite navigation system

18. Accurate and precise knowledge of motion
over timescales of years

20. What we are learning from GPS 1) Plate tectonic assumptions OK- but only to first order- Within plate deformation can be huge 2) How continents deform during orogenesis- diffuse? plate like? 3) What parts of faults are slipping vs. what parts are "locked" up- important for EQ predictions 4) unprecedented knowledge of recent movements on Earth

21. GPS is great, but requires lots of stations and time to wait around.
Scientists are greedy- we want more data on ground motion and with less effort- is it possible?

22. Scientific advancements
are simply awesome!
Wide-area, high-precision
surveying from Space
Satellites beam microwave
radiation (radar) down on
Earth

23. The Earth reflects back to the satellite microwaves of different phases that yield X,Y,Z information.

24. Two passes of a satellite with imaging radar over the same area produce two images. The difference between two images provides the displacement field over the entire area (often, 100 km 100 km) between the time of the two passes.

25. A simple, schematic example

26. A real example- ground motion due to an earthquake in a thrust belt

27. Movement of glaciers over six days- think about how many GPS stations would be required to provide this kind of detailed information

28. Displacement due to an EQ in Turkey
Displacement due to an EQ in Turkey. Can also determine displacement in between EQ's!

29. Landers Earthquake

30. This technique is called InSAR- for Interferometric Synthetic Aperture Radar. The potential is endless!

31. It is estimated that a magnitude 8 or larger earthquake in a major metropolitan area, such as Los Angeles or Tokyo would cause more than 40,000 fatalities, up to 250,000 injuries, and $100 billion dollars in damage
What else do we need to know to be able to predicts earthquakes?

33. 1) study deformed historic sites of known ages (Great Wall of China)
Study the earthquake cycle- recurrence intervals of major events through neotectonic studies
1) study deformed historic sites of known ages (Great Wall of China)
2) Paleoseismology
3) offset geomorphologic surfaces + surface dating

35. Paleoseismology
San Gorgonio, CA

36. Paleoseismology:
results for one fault
system

37. Fault-scarp profiling- gives displacement and age—
as well as other interesting info regarding structure

38. Laser theodolite for
surveying. Gary Axen
wishes that a satellite
would fly over and beam
down those microwaves!

39. A cheaper way to
fly!

40. Long term plate motion- 5 cm/yr
Neotectonic mapping
400 m in yrs
40 mm per year
Long term plate motion- 5 cm/yr

42. The scarp hidden by the waterfall is about 7 meters high. 
The bridge failed where it crosses the fault to the right a few
hundred meters, out of the frame of the photo.  It is being
reconstructed in the same location.

43. Visit the following website:
Assignment
Visit the following website:
Surf around. Check out the cool animations! Download 4 of your favorite geology-related images. Then to me This will be graded as a "What is it quiz".