Fault Mechanism

1. Department of Earth Sciences KFUPM Introduction to Seismology Fault Mechanism Introduction to Seismology-KFUPM Ali Oncel [email_address] http://www.learninggeoscience.net/free/00071/index.html

3. What type of faulting? A normal faulting mechanism. Which plane do you think is the fault plane ? A reverse faulting mechanism. Which plane do you think is the fault plane ? Strike-slip faulting. Which strike? Introduction to Seismology-KFUPM

4. Introduction to Seismology-KFUPM

5. Introduction to Seismology-KFUPM

7. Focal Mechanism Map Introduction to Seismology-KFUPM

8. Now, you can download the map under different options. JPG is easy to download but *.PS is good if making up for picture is needed. Introduction to Seismology-KFUPM Now, just click on the option “JPG” and see the map of focal mechanisms.

9. Introduction to Seismology-KFUPM

10. What is CMT? Introduction to Seismology-KFUPM

13. Large Earthquakes (5 yr) The boundaries of plates are evident from the pattern of earthquake activity. Introduction to Seismology-KFUPM

14. Active vs. Passive Continental Margins Earthquakes lie mostly along the boundaries of moving plates. Introduction to Seismology-KFUPM Parks and Plates ©2005 Robert J. Lillie

15. Active vs. Passive Continental Margins Introduction to Seismology-KFUPM The nearest plate boundary to the U. S. East Coast is the Mid-Atlantic Ridge. Parks and Plates ©2005 Robert J. Lillie

16. Marshak, EARTH (Norton, 2005) Active vs. Passive Continental Margins Parks and Plates ©2005 Robert J. Lillie The U. S. West Coast lies along a convergent plate boundary , and is thus an ACTIVE CONTINENTAL MARGIN . Introduction to Seismology-KFUPM

17. Active vs. Passive Continental Margins The U. S. East Coast is far from a plate boundary , and is thus a PASSIVE CONTINENTAL MARGIN . Parks and Plates ©2005 Robert J. Lillie Introduction to Seismology-KFUPM Marshak, EARTH (Norton, 2005)

18. Axis of the oceanic ridge is offset by transform (strike-slip) faults which produce lateral displacement. Ridges and rifts indicate movement . Earthquakes at Mid-Ocean Ridge System Introduction to Seismology-KFUPM

21. Introduction to Seismology-KFUPM Fig 7.22 of Lillie

22. Introduction to Seismology-KFUPM

23. Introduction to Seismology-KFUPM

24. Introduction to Seismology-KFUPM

25. Introduction to Seismology-KFUPM

26. Introduction to Seismology-KFUPM

27. Introduction to Seismology-KFUPM