introduction to shear wave splitting l.
Download
Skip this Video
Download Presentation
Introduction to Shear Wave Splitting

Loading in 2 Seconds...

play fullscreen
1 / 13

Introduction to Shear Wave Splitting - PowerPoint PPT Presentation


  • 504 Views
  • Uploaded on

Introduction to Shear Wave Splitting. Erin Elliott Guofeng Yuan February 26, 2010. Outline. Concept Definitions History Applications Common Misunderstandings Conclusions . What is Shear Wave Splitting?.

loader
I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
capcha
Download Presentation

PowerPoint Slideshow about 'Introduction to Shear Wave Splitting' - muncel


Download Now 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.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript
introduction to shear wave splitting

Introduction to Shear Wave Splitting

Erin Elliott

Guofeng Yuan

February 26, 2010

outline
Outline
  • Concept
  • Definitions
  • History
  • Applications
  • Common Misunderstandings
  • Conclusions
what is shear wave splitting
What is Shear Wave Splitting?
  • When a polarized shear-wave enters an anisotropic medium, it splits into two quasi shear-waves (fast and slow).
shear wave splitting seismic birefringence
Shear Wave Splitting (Seismic birefringence)

http://garnero.asu.edu/research_images/anis/garnero_splitting.gif

definitions
Definitions
  • Microcrack
  • Azimuthally Aligned
  • Polarization Diagrams
microcracks
Microcracks

Crack density

azimuthally aligned
Azimuthally Aligned
  • the angles that the arrivals or waves make with a reference point are all equal.
  • The waves are approximately parallel:

http://en.wikipedia.org/wiki/Azimuth

polarization diagrams hodograms
Polarization Diagrams(Hodograms)
  • Displays a 2-D projection of the trajectory of a point moving in space.
  • a cross plot of two components of motion over a time window.

http://www.crewes.org/ResearchLinks/ExplorerPrograms/Hodogram/Hodogram.html

applications
Applications
  • Possible earthquake prediction
    • for earthquakes M 1.7 to M 7.7
  • CO2 Injection mapping
    • in fractured carbonate reservoirs
common misunderstandings
Common Misunderstandings
  • Polarizations of split shear waves are orthogonal
  • Crack anisotropy always decreases with depth as fluid filled cracks are closed by lithostatic pressure.
  • Signal-to-noise ratios of shear-wave splitting above small earthquakes can be improved by stacking.
conclusion
Conclusion
  • Stress aligned fluid-saturated microcracks are the predominant cause of the nearly universal observations of azimuthally aligned shear wave splitting both in the earth’s crust and in the upper mantle.
ad