lecture 16: deformation in the crust and the mantle read kk&v...
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Lecture 16: Deformation in the crust and the mantle Read KK&V chapter 2.10 HW5 is due today
Crystal la)ce
Migra/on of disloca/ons through crystals
Disloca/on density increase with stress
LiNbO3
Disloca/ons in quartz
Hirth and Tullis, 1992
Disloca/on density vs differen/al stress
Durham et al., 1977
slope of ~0.6
Disloca/on velocity: dependence on stress and temperature
Sta/c re-‐crystalliza/on
Sta/c re-‐crystalliza/on: example
Freed and Burgmann, 2004
Hector Mine eq
Freed and Burgmann, 2004
Postseismic relaxa/on: /me dependence
Post-‐glacial rebound from GRACE data
Post-‐glacial rebound from geode/c data
Post-‐glacial rebound from geologic data
Effective rheology
dislocation creep
ij
εv = εD + εG = ADσnD + AGd
−mσ nG
d = d0σ−r
diffusion creep
equilibrium grain size
nD ~ 3nG ~1m ~ 3r ~1
A =C exp −QRT
"
#$
%
&'
Arrhenius temperature dependence
Stocker and Ashby, 1973
Deforma/on map: olivine
ε1
ε1 < ε2