Geoscience Reference
In-Depth Information
Table 1.1
( cont. )
Mantle
Oceanic
As
As above
MOR
CMB
transform
continent
and
faults
oceanic
volcanic
plumbing
Plumes
Lithospheric plate
Major
Low velocity
As above
Plate
faults
zone
graveyard at
CMB
Asthenosphere
Mantle
Plume
CMB
convection
heads
currents
Magma melt
Magma
CMB
chamber
plume
mixing
sources
Fe-Ni
Core
Inner
liquid
fluid
core
masses
boundary
Note the scope for interactions between subdisciplines concerned with studying Earth processes. Even deep planetary interfaces, normally the playgrounds for solid state physicists, have
relevance to surface-orientated Earth scientists. ABL: atmospheric boundary layer; MOR: mid-oceanic ridge; CMB: core-mantle boundary; MOHO: Mohorovicic discontinuity.
Ozonosphere (45 km thick) Ozone layer where
photons of ultraviolet light cause continuous reversible
oxygen disassociation to ozone via the Chapman cycle . This
is perhaps the first Earth layer to receive focused “environ-
mental” attention due to the discovery in the 1970s of the
role of human-produced chlorofluorohydrocarbons in
ozone destruction at polar latitudes.
Troposphere (18 km thick) Gas, chiefly N 2 and O 2 with
aerosols of solid dust and liquid water.
Oceans (average 3.8 km deep) Liquid water with
dissolved ions, chiefly Cl , Na , SO 4 , Mg , and Ca .
Continental crust (average 30 km thick) Crystalline
silicate solid, granite-rich. Chief elements are Si, Al, K, Na.
Lower boundary with mantle defined at MOHO, marked
by increase in density.
Oceanic crust (average 10 km thick) Crystalline
silicate solid, basalt-rich. Chief elements are Si, Al, Ca, Fe,
and Mg. Lower boundary with mantle defined at MOHO,
marked by increase in density.
Mantle (2,858 km thick) Crystalline silicate solid/
plastic rich in Mg and Fe elements. Upper boundary with
crust at MOHO, defined by marked decrease in density.
Core (3,480 km thick)
Cryosphere Solid water in ice caps up to 5 km thick,
also seasonal as permafrost.
Hydrosphere Liquid water in oceans, lakes, and rivers.
Also as liquid phase in crustal rocks and soils.
Lithosphere
km of mantle
and crust, defining moving lithospheric plates.
Asthenosphere ( Low Velocity Zone, LVZ )
Relatively rigid outer 100
100-200 km
thick, partially molten (
1 percent by volume) mantle
below lithosphere.
Mesosphere
Most of the mantle below the LVZ , as in
Section 1.5.2.
Outer core
Metallic (Fe-Ni) molten liquid.
Inner core
Metallic (Fe-Ni) solid.
1.5.4
Outer Earth layers defined by temperature
Thermosphere
C upward. Rare gas
molecules warmed by extreme ultraviolet radiation.
Mesosphere ( c .50-85 km)
(85
km)
80
0
C to
80
C. The ozone
effect decays upward.
Stratosphere ( c .18-50 km)
60
C to 0
C. Warming
Metallic center of Earth, rich
trend as heat is released by ozone formation.
Troposphere (0- c .18 km)
in Fe and Ni.
C. Well mixed,
warmed by greenhouse effect. Cooled as greenhouse
effect decays upward.
Ocean water layers (North Atlantic Deep Water, etc.)
(100s-1,000s m)
15
C to
60
1.5.3
Earth layers defined by state
Atmosphere Gaseous envelope with clouds and weather,
containing traces of particles and aerosols.
Vary in temperature by up to a few
degree centigrades.
 
Search WWH ::




Custom Search