cider & superdomes

CIDER & Superdomes

Eh TanCIG

at CIDER Workshop 2009

DensityD

epth

normal Ks

high Ks

• Motivation: anti-correlation of V and Vs

• Suggesting high Ks material

DensityD

epth

normal Ks

high Kshigh 0

DensityD

epth high Ks

high 0

high Kshigh 0

high T

DensityD

epth high Ks

high 0

high Kshigh 0

high T

Tan and Gurnis, GRL, 2005

DensityD

epth high Ks

high 0

high Kshigh 0

high T

Tan and Gurnis, GRL, 2005

DensityD

epth high Ks

high 0

high Kshigh 0

high T

Tan and Gurnis, GRL, 2005

DensityD

epth high Ks

high 0

high Kshigh 0

high T

Tan and Gurnis, GRL, 2005

DensityD

epth high Ks

high 0

high Kshigh 0

high T

Tan and Gurnis, GRL, 2005

Composition Temperature

Tan et al, in preparation

Composition Temperature

VpVs

http://www.geodynamics.org

Conclusion

• Preferred parameters for high-Ks superdomes: KS = 6% ~ 8%, = 2% ~ 3% at surface KS = 6% ~ 8%, = 0.5% ~ 1.5% at CMB pressure,

normal mantle temperature KS = 1% ~ 2%, = -0.5% ~ 0.5% at CMB

pressure, elevated temperature (+ 500K ~ 1000K)– depends on the thermal expansion, viscosity

contrast, and the temperature of the mantle and CMB• Not an unique dynamic interpretation of the

superdomes, but the most viable one

Tan and Gurnis, JGR, 2006

Speculation

• Mineral physics– Fe: ~ KS, ++

– Si: ++ KS, +

– Al, Ca, Na: ???• Superdome material: +Si, +?Fe• Original of the material?• Geochemical implication?

CIDER & Me

• 2 weeks at 2004• 1 day (Intro to CIG) at 2006• 2 days (Geodynamics Tutorial) at 2008

CIDER Summer Workshop

• Education component is very successful– we should keep doing it

• Extends research component, how?

CIDER

• 2+2 weeks tutorial+workshop• Inter-disciplinary collaboration during

the workshop• How to sustain the collaboration beyond

the workshop?• Web discussion forums?• Exchanging program?

Working Group• Past experience

– several benchmarks for numerical geodynamics codes– REM

• Difficulty– long term investment: >2yr– distracted by daily work

• Needs a person to push the group forward– volunteer leader?– CIDER-sponsored (partially) post-doc or grad student?