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 spreading- process 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 Age Measured distance and the age of the sea floor As distance from the Ridge increases the age of the sea floor increases Distance from ridge Age 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