Continental Drift and Features of the Sea Floor Flashcards
Who developed the Continental Drift hypothesis and when was it developed?
Alfred Wegener (1915)
What is Pangaea?
A supercontinent that existed 300 mya
Describe Wegener’s idea of Continental Drift
That they fit together like puzzle pieces, and were once one land mass and broke apart
List the three types of evidence Wegener used to support his idea
Landforms/rocks, climate, fossils
What vocab to help:
Glacier scratches- Climate, Freshwater reptiles- Fossils, Mountain ranges lined up- Land forms
Why did scientists find fossils of tropical plants on islands in the Arctic Ocean near the North Pole?
Continents were closer to the equator until they moved. We found tropical plants in Antartica
Coal deposits have been found beneath the ice of Antarctica, Explain how coal is found so close to the south pole.
It was close to the equator. Coal forms in wet, swampy regions.
What device was used in the 1960s to map the ocean floor?
SONAR
How does this device work?
Maps the ocean floor with sound waves. Bounces off objects and returns back to the ship.
Scientists discovered what major feature of the ocean floor when using this device:
The Mid Ocean Ridge
Continental Slope:
The STEADY DECLINE at the EDGE of the continental shelf
Continental Shelf:
A GENTLE, SLOPING, SHALLOW area that EXTENDS OUT from the EDGE of a continent
Deep Ocean Trench
A DEEP VALLEY on the ocean FLOOR through which ocean floor is PUSHED into the MANTLE
What’s a plate?
A section of the LITHOSPHERE (Crust) that slowly MOVES carrying PIECES of CONTINENTS, OCEAN FLOOR, or both
How many plates make up the Earth’s crust?
About 15 plates
