1. Explain the force that moves the continents.

2. Write today’s date and EQ on page 77.

What is the evidence for continental drift?

Wegener1880-1930

earthobservatory.nasa.gov

Alfred Wegener first proposed the theory of continental drift.

Continental drift was Wegener’s theory that all continents had once been joined together in a single landmass and have drifted apart since.

Wegener named this supercontinent Pangaea.

Wegener’s theory was rejected by scientists because he could not explain what force pushes or pulls continents.

Continental drift video clip

Fit of Continents Across the Atlantic

Mountain ranges in South America line

up exactly with those in Africa!

Notice how fossils lined up across continents!

http://evolution.berkeley.edu/evolibrary/images/history/fossils3.gif

Amazing Facts: Did you know...

...that India was once in the Southern Hemisphere connected to Antarctica? ...that North America was once surrounded by warm, tropical seas? ...that Africa was once covered by glaciers, which were kilometers in thickness? ...that the Sahara desert was once a tropical rain forest?

As North America has drifted to different latitudes, changing climates were experienced. This shows the changes in the state of New Mexico.

An example of the proof for changing climate:

At one time, the area that is New Mexico was below the equator!

He could not find the force that was causing the continents to drift.Because of this, he could not convince anyone that continents could move.He died in Greenland on an expedition. At the time of his death, no one believed his hypothesis!

Technology developed during the 1940’s changed all that!