Early Ideas and Continental Drift

Who was the scientist that first proposed the idea of continents moving?

Alfred Wegener: Thought of Pangea, since drifted for millions of years

Who is the scientist that followed later with the correct idea of the continental drift?

Harry Hess: Thought of sea-floor spreading

Why was Wegeners idea more widely accepted after time? Describe 3 reasons

Paleomagnetism: Evidence of magnetic reversals in ocean crust.

Seafloor spreading: New crust forms at mid-ocean ridges and trenches

Development of new technology like: Sonar and satellite imaging of the sea-floor

What was the discovery that soldified Wegeners theory?

Confirmation of sea-floor spreading

Name two evidences for sea-floor spreading that proved that the plates are moving away from each in the Atlantic

Magnetic striping: Showed new crust pushing away the old crust

Oceanic crust: Youngest crust gets older as you move further away

Draw and label a convection current diagram

Arrow is the direction of the fluids movement

Describe the layers of earth according to their physical properties

Lithosphere: Broken into plates

Asthenosphere: Like hot tar

Lower mantle: Convection currents

Outer liquid core: Layer of molten

Solid inner core: Active decay

Describe the layers of the earth according to their composition

Crust: Continental crust made of granite rocks and oceanic crust is made of basalt rocks

Mantle: Mostly iron and pieces of crust

Core: Iron and nickel

Identify the following major plates

North American Plate

South American Plate

African Plate

Eurasian Plate

Pacific Plate

Indian Plate

Antarctic Plate