Transcript Deep Earth Materials

Materials Sense:
Integrating
Earth Materials
into a Deep Earth
Curriculum
our goal
is to develop our
physical intuition for
Earth Materials
Materials of the Deep Earth
Integrating Earth Interiors into
Mineral Sciences Curricula
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Three most
abundant elements
in the Earth
Earth Materials
Physical Properties
Earth Model
Elements of The Earth
stellar
spectra
Indirect evidence:
reveal
composition
Solar Spectra
Meteorites
Hand samples
Experiments
Each set of lines
is a “fingerprint”
for each element
Earth Materials
Physical Properties
Earth Model
Atomic-scale structure governs
the physical and chemical behavior of
rocks and minerals
case 1: Single-size spheres
Earth Materials
Physical Properties
Earth Model
Iron in the Earth’s Core? Anisotropy?
cubic
close
pack
body
center
cubic
www.ldeo.columbia.edu/~richards/Jefflec.html
Earth Materials
Physical Properties
Earth Model
Atomic-scale structure governs
the physical and chemical behavior of
rocks and minerals
case 2: Two-different size spheres:
O and Si
Earth Materials
Physical Properties
Earth Model
pressure
0
25 GPa
tetrahedral
(SiO4)
octahedral
(SiO6)
O
Si
coordination
Earth Materials
Physical Properties
Earth Model
Mantle Mineralogical Model
Earth Materials
Physical Properties
Earth Model
Basic Units
Definition
SI Unit
Example
distance
meter m
Prof. Kavner
time
second s
Heartbeat
mass
kilogram kg
Laptop
density
Kg/m3 or g/cm3 1 water, 3 rock 8 iron
Students should know definitions, units,
and examples from daily life and Earth
Earth Materials
Physical Properties
Earth Model
Derived Units
10 Earth’s gravity
acceleration (a)
m/s2
force (F)
N, Kg*m/s2 fall of small object
pressure (F/area) Pa
Earth pressure (GPa)
energy
Joules
mechanical, heat, etc.
power
Watt, J/s mechanical, heat, etc.
Earth Materials
Physical Properties
Earth Model
Energy and constitutive properties
Conjugate Variables
Equilibrium Properties
Transport Properties
(energy units)
Stress-Strain
Elastic Constants (GPa)
Viscosity (Poise, Pa s)
Pressure-Volume
Bulk Modulus (GPa)
Elastic wavespeeds (m/s)
Temperature-Entropy
Heat Capacity (Joule/mol/K) Thermal Conductivity (W/m/K)
Chemical potential-moles*
Electric field-current
Phase diagram
Chemical Diffusion (m2/sec)
Electrical conductivity (ohms)
Isotropic vs. Anisotropic
Earth Materials
Physical Properties
Earth Model
Which mineral will have
anisotropic physical properties?
Earth Materials
Physical Properties
Earth Model
Deep Earth Toy Model
Purpose:
To gain physical intuition for properties
of deep Earth materials
Goal:
Calculate density and wavespeeds as a function of
pressure for variety of deep Earth minerals, and
compare with PREM
Abilities:
Can map compositional changes and temperature
variations
onto seismic observables (wave velocity variations)
Earth Materials
Physical Properties
Earth Model
Mantle Mineralogical Model
Earth Materials
Physical Properties
Earth Model
Deep Earth Toy Model (Excel)
Earth Materials
Physical Properties
Earth Model