1 / 16

Is inner core translation a good model ?

Is inner core translation a good model ?. Vernon Cormier, Lizzie Day, Zack Geballe, Marine Lasbleis , Mohammad Youssof , Han Yue. Does the inner core grows layer by layer?. Does it convect ?. Deguen , 2012. Summary of s eismic features. SLOW isotropic velocity

donnel
Download Presentation

Is inner core translation a good model ?

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. Is inner core translation a good model? Vernon Cormier, Lizzie Day, Zack Geballe, Marine Lasbleis, Mohammad Youssof, Han Yue

  2. Does the inner core grows layer by layer? Does it convect? Deguen, 2012

  3. Summary of seismic features • SLOW isotropic velocity • Less attenuation (high Q) • More anisotropic • FAST isotropic velocity • More attenuating (low Q) • Less anisotropic West East Inner inner core? Modified from a figure by Jessica Irving

  4. Hemispheres of P-wave travel time Waszek & Deuss, JGR, 2012

  5. T-dependent viscoelasticity is not the cause East West

  6. Composition is an unlikely cause < 8.8 mol % Si 8.5 mol % Si Cottaar and Buffet (2012) Alfe et al. (2002)

  7. Translation: a type of convection Slow Fast Monnereau et al., Science, 2010

  8. Age distribution in a translatinginnercore 0 km 100 km Age (Ma) 500 km 300 km 0 75 150

  9. Average age sampled by imaginary seismic data set

  10. Age domain size seismicproperties

  11. Model explains the Vphemispheres!

  12. 1 elasticity model fits, 5 do not

  13. Tuned parameter #2: Domains grow to ~ λseismic/2π Calvet and Margerin, 2008

  14. Q from model < observed Q

  15. Other seismic features West East Inner inner core? Modified from a figure by Jessica Irving

  16. Future tests • Try to explain innermost inner core with a textured polycrystalline scattering model • Test a spectrum of iron elasticity models • Map Vp in different frequency bins • Map Q Conclusion: Rigid translation is consistent with observed hemispherical variation in Vp provided that: domains grow to approximately λSeismic/2π , the iron alloy making up the inner core has relatively high elastic anisotropy

More Related