1 / 32

Faults and Earthquakes

Faults and Earthquakes . BASIC DEFINITIONS. FAULT : A surface or narrow zone along which one side has moved relative to the other. Faults are classified based upon their direction of movement. . HANGING WALL vs FOOTWALL. A fault divides rock into two fault blocks

annis
Télécharger la présentation

Faults and Earthquakes

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Faults and Earthquakes

  2. BASIC DEFINITIONS • FAULT: A surface or narrow zone along which one side has moved relative to the other. • Faults are classified based upon their direction of movement.

  3. HANGING WALL vs FOOTWALL • A fault divides rock into two fault blocks • For any inclined fault, the block above the fault is the hanging wall block, and the block below the fault is the footwall block www.data.scec.org/Module/footnt02.html

  4. CLASSIFICATION of DIP-SLIP FAULTS • NORMAL FAULTS: Dip-slip faults on which the hanging wall moves down relative to the footwall • Place younger rocks on older rocks • Form in regions of lateral extension www.data.scec.org/ Module/footnt02.html

  5. EXAMPLES OFNORMAL FAULTS Outcrop scale normal faults Conjugate Normal Faults, Canyonlands National Park darkwing.uoregon.edu/~millerm/conjN1.html Normal Fault Scarps, Turkey www.msnucleus.org/.../pt/hazards/4/pth4_1a.html

  6. CLASSIFICATION of DIP-SLIP FAULTS • THRUST or REVERSE FAULTS: Dip-slip faults on which the hanging wall moves up relative to the footwall • Place older rocks on younger rocks • Form in regions of lateral compression www.data.scec.org/ Module/footnt02.html

  7. Outcrop scale thrust faults www.pitt.edu/.../7Structures/ReverseFaults.html EXAMPLES OFTHRUST FAULTS Thrust Fault in Concrete from 1964 Quake, Anchorage, Alaska www.ucmp.berkeley.edu/.../alaska/0709log.html Thrust Fault in Sediments www001.upp.so-net.ne.jp/fl-fg/05-01.htm

  8. CLASSIFICATION of STRIKE-SLIP FAULTS • RIGHT-LATERAL (DEXTRAL) FAULTS: Strike-slip faults across which the block moves to the right • LEFT-LATERAL (SINISTRAL) FAULTS: Strike-slip faults across which the block moves to the right

  9. Right Lateral Fault in Asphalt www.uwsp.edu/.../fault_transform_photo.html EXAMPLES OFSTRIKE-SLIP FAULTS San Andreas Fault, CA http://education.usgs.gov/california/ pp1515/chapter2/fig2-21.jpg Right Lateral Slip, Izmit, Turkey, 1999 Quake http://www.geo.uib.no/jordskjelv/ index.php?topic=earthquakes&lang=en

  10. Earthquakes

  11. Epicenter and Focus

  12. Seismograph and Seismogram

  13. Determining Earthquake Distance

  14. Locating an Epicenter

  15. Global Seismicity

  16. Richter Scale…A Measure of Earthquake Size

  17. Convergent Plate Boundaries

  18. SumatraSite of M9.3 Earthquake,December 26, 2004

  19. Convergent Plate Boundaries

  20. ChileSite of M9.5 Earthquake,May 22, 1960

  21. Convergent Plate Boundaries

  22. PakistanSite of M5.2 Earthquake,July 16,2005

  23. Transform Plate Boundaries

  24. San Andreas FaultBoundary Between the North American and Pacific Plates

  25. San Andreas FaultSan FranciscoSite of M7.8 Earthquake, April 18,1906

  26. Plate Boundaries

  27. Seismicity of the US, 1968-2003, M>3.5

  28. NE Seismicity 1977-1999 (22 Years) Blue Circles: M≥4

  29. Seismic Zones for Building Codes

  30. Liquifaction…

  31. Manhattan Site Classes, Census Track - Based A Hard Rock 0.8 B Firm Rock 1.0 C Firm Soil 1.7 D Soil 2.4 E Soft Soil 3.5 Amplification at 1.0 Hz

More Related