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shell tectonics. Numerical modelling of shell tectonics during terrestrial planetary accretion. Taras Gerya. Paul Tackley. David Yuen. Ja-Ren Lin. U of M. NTU Taiwan. ETH– Zurich. ETH– Zurich. shell tectonics. Primordial core fragmentation. (Stevenson, 1981). SHELL TECTONICS.
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shell tectonics Numerical modelling of shell tectonics during terrestrial planetary accretion Taras Gerya Paul Tackley David Yuen Ja-Ren Lin U of M NTU Taiwan ETH– Zurich ETH– Zurich
Primordial core fragmentation (Stevenson, 1981) SHELL TECTONICS
Primordial core fragmentation ppv D“ (Stevenson, 1981) SHELL TECTONICS
SHELL TECTONICS ??? ??? Plate tectonics observations concepts models
Hidden power of b&w sketches... (Stevenson, 1981)
What do we need for modeling of SHELL TECTONICS ? • Visco-elasto-plastic rheology • 2. Large deformation • 3. Free surface • 4. Spherical geometry
What do I have ? ? • Visco-elasto-plastic rheology • 2. Large deformation • 3. Free surface • 4. “Spherical Cartesian” geometry
"Spherical Cartesian" Modeling spherical planets on Cartesian grid
Why not Cartesian ? material heat flow flow momentum equation continuity equation temperature equation Cp[(T/t) + vi(T/xi)] = [k(T/xi)]/xi + (H/t)
Why not Cartesian ? Gerya & Yuen (2007)
SELF GRAVITY Gravity potential Gravity vector amplitude gz gx Gerya & Yuen (2007)
"Spherical Cartesian" Check it out!
Setup: "Cubic Earth" Planet 3300 kg/m3 1021 Pa s Continents 3000 kg/m3 1020 Pa s „Space“ 1 kg/m3 1018 Pa s
"Spherical Cartesian" How spherical is it ?
It is very cylindrical in 2D... pressure
SOFT SHELL TECTONICS