Plate Tectonics

Drawing slide

In your notes…

Plate Tectonics Pieces of the lithosphere (crust) that move around Each plate has a name based on the name of the continents and oceans nearby. Fit together like jigsaw puzzles Float on top of the asthenosphere (mantle)

Tectonic Plates Which plate is made of all oceanic crust? What does that tell me about its density? Free response

What do the locations of Volcanoes and Earthquakes tell us? Answer the question

Ring of Fire -An area where many Earthquakes and volcanic eruptions occur. Which plate does the ring of fire outline?

Fault Lines Earthquakes and volcanoes often occur on fault lines. Fault lines are found where two plates come together. Plates can move in different ways at faults. San Andreas fault, California

Continental Drift -Alfred Wegener: Continents were once a single land mass that drifted apart. -He called this supercontinent Pangea, Greek for “all Earth” -Could we use today’s maps 50,000 years from now? Why or Why not? Answer the question

How do we know? Landforms – Mountain Ranges in N. America are made of same rock as European Mountain Ranges. Geology – Matching geologic trends between east coast of S. America, N. America, and Africa Fossil Record– Same organisms were native to S. America, Africa, India, and Australia, meaning those continents had to be closer together at some point.

Evidence of Pangea What does the diagram show us about the fossil record?

How Plates Move What is happening that is moving the plates?

Sea Floor Spreading Mid Ocean Ridges – underwater mountain chains Magma rises to the surface and solidifies and new crust forms Older Crust is pushed farther away from the ridge

Sea Floor Spreading