Download What is the Plate Tectonic Theory?

What is the
Plate Tectonic
Theory?
How is it different than the
Continental Drift Theory?
Plate Tectonic Theory
• Plate Tectonic Interactive Map
• Adds to Wegener’s Theory of Continental Drift.
• States the lithosphere is divided into broken
pieces (tectonic plates) that are shifting over
the asthenosphere (upper mantle).
• *** So instead of the continents drifting, the
lithospheres crustal plates (which is part
continental and oceanic crust).
Evidence to Support the Plate Tectonic
Theory
• All of the previous evidence Wegner used
to support the continental drift theory.
• Earthquakes, volcanoes, and mountains
are most frequent along plate boundaries.
**** It is unlikely for an earthquake or
volcano to occur in areas like NY b/c we
are far away from an actual plate
boundary.
Sea floor Spreading
•
sea floor spreadingprocess by which the
seafloor widens as it
• Magma rises at a rift and
pushes the two plates
apart
• Ages of the Rocks and
volcanic islands match on
either side of the Rift
• As the distance from the
ridge the age of the volcanic
island increases
Age of the Sea floor
• Measured distance and
the age of the sea floor
• As distance
from the Ridge
increases the
age of the sea
floor increases
A
g
e
Distance from ridge
A
g
e
S.A
M.A.R
Africa
Magnetic Pole Reversals
• Prove sea floor
spreading because
there is a matching
pattern of pole
reversals on either side
of the ridge.
•
Scientists believe the earths
magnetic poles have flipped
multiple times because of the
molten metal outer core is
spinning with the earth.
*** This has not been proven yet it
is a hypothesis
Video discussing flips
in polarity