Download earth interior - Red Hook Central Schools

Dynamic Earth
In an Earthquake, the rocks in the
crust of the Earth rip and break
apart, releasing tremendous energy
in the form of seismic waves.
What’s it like to be in an Earthquake?
“Its like trying to stand up in an airplane
during severe turbulence”
Evidence for historical motion of the
Earth’s crust:
Original Horizontality
Sedimentary rocks are always deposited in
horizontal layers called strata.
Now we see sedimentary rocks that are
“messed up”.
Horizontal rock
strata.
Tilted Strata
Folded Strata
• animation of folding
Faulted Strata
Another Fault
•
•
•
•
normal fault
strike slip
reverse fault
thrust fualt
• Produce energy waves called seismic waves
that travel through the Earth
• Seismologists use these waves to investigate
the internal structure of the Earth, like a
doctor uses x-rays to investigate the internal
structure of a person
Seismic waves tell us that Earth has
3 layers:
• Crust (solid rigid outer rock layer)
Moho separates crust from mantle
• Mantle (beneath the crust, not so solid)
80% of Earth is mantle
• Core (outer core = liquid, inner core = solid)
made of nickel and iron (magnetic)
very dense!
Earths interior animation
Layered Earth
Lithosphere = Crust + upper (rigid)
mantle
Asthenosphere = partly molten part of
mantle below the lithosphere (plastic
mantle), convection currents here!
Stiffer Mantle= below the
asthenosphere
Upper portion of Earth
plates
There are two types of CRUST:
Oceanic Crust = basalt rock, dense, mafic, thin layer
Continental Crust = granitic rock, less dense, felsic
thicker layer
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