Chapter 2: Plate Tectonics

Question 1

What is Plate Tectonics

Answer 1

Plate Tectonics states that the earth’s lithosphere is broken into a number of slabs of rock called plates

Question 2

Who proved the theory of plate tectonics

Answer 2

Frederick Vine and Drummond Matthews in 1963

Question 3

Who came up with earlier theories about plate tectonics

Answer 3

Continental Drift - Alfred Wegner 1912
Convection Currents - Arthur Holmes 1928
Mid-Ocean Ridges - Maurice Ewing 1947
Sea Floor Spreading - Harry Hess 1962

Question 4

What is Continental Drift

Answer 4

Suggests that the continents are constantly moving across the planet by convection currents

Question 5

What evidence is there to back up the theory of Pangaea (the supercontinent)

Answer 5

Continental Fit

Matching plant fossils
Matching rocks and mountains
Glacial deposits in countries with climates that would not create glaciers

Question 6

What are convection currents

Answer 6

As the magma (6000 degrees C) becomes hotter it rises towards the crust. Upon reaching the upper mantle, it cools and becomes semi-molten. It then moves laterally before sinking again. As the magma moves sideways it rubs off the lithosphere causing friction which leads to plates separating, colliding and sliding past each other.

Question 7

What is slab-pull force

Answer 7

When the edge of a plate begins to sink into the mantle, it then pulls the rest of the plate after it.