PTR - Continents over Time Lesson

 

Continents over Time

Multiple lines of evidence suggest that the continents are not stationary, but are in fact moving slowly around the Earth as the plates on which they rest are pushed by the convection currents in the asthenosphere. By utilizing the data that has been collected so far, scientists are able to "rewind" these movements to determine what the Earth would have looked like millions of years ago. When these computer models are run at high speed, the continents appear to drift through the oceans like ships (or bumper cars).

Watch the video below to see the plate tectonics shift:

Watch the video below to see the continental drift:

As continents drifted over the millennia, coming together and splitting apart, ocean waterways would form and later be cut off. In the video above, notice that there was a vast inland sea that divided eastern and western North America from ~100-70 million years ago. The current oceans - Pacific, Atlantic, Indian, and Arctic - have not always existed; while all of the modern-day continents were joined together as the supercontinent known as Pangaea (300-175 million years ago), the land mass was surrounded by a single body of water known as Panthalassa. As the continents broke apart and moved to their current positions, Panthalassa became smaller, and the other bodies of water formed (the Pacific Ocean is the remnants of Panthalassa).

 

 

 

IMAGES CREATED BY GAVS OR OPENSOURCE