Continental drift
Continental drift was founded by Alfred Wiener in 1912. Continental drift is the movement of the earth’s continents relative to each other by appearing to drift across the ocean bed. The idea of continental drift came from plate tectonics.
- Australia, South America, Antarctica, India, Africa, and Madagascar were all together until the global continent Pangaea broke up.
- Japan and other places have earthquakes that are caused by continental drift and plate tectonics.
- The continents could all fit together until continental drift occurred, the picture above of them splitting apart shows this theory.
SEA FLOOR SPREADING
Seafloor spreading is the process that occurs at mid-ocean ridges, where a new oceanic crust is formed through volcanic activity. Seafloor spreading helps explain continental drift in the theory of plate tectonics. Old rocks will be found further away from the spreading zone and younger rocks will be found near the spreading zone.
This is a picture of two plates being spread apart. The left plate is going in the same direction as the right plate of the crust. That means the two plates are colliding together, one has to go on top of the other. Another example is boundaries being expanded from the central axis.