Friday's Class- Jan. 23, 2009

The Sea Floor/Ocean Crust/Land Crust

• 71% of the world is Ocean
• World is made up of 4 Basins-Atlantic, Indian, Arctic, and Pacific oceans
• Earth is 4.5 billion years old
• Ocean Crust-Basalt, thin, more dense, oldest rock 200 million years old
• Continental crust-granite, thick, less dense, oldest rock 3.8 billion years old

Layers of the Earth

• Crust-5-7 KM thick
• Mantle-3000 KM thick/Divided into Lithosphere, Asthenosphere and Lower Mantle
• The Core- Made up of iron and nickel/ Divided into Outer and Inner Core

Heat and Energy

• Radiation-Transfer of Energy through space
• Convection-Heat transfer by movement of liquids
• Convection Current- Flow of heat
• Convection Currents in Earth- Heat in core causes convection in mantle

Alfred Wegner- hypothesized that continents were once connected and called "Pangea"

• Evidence of Pangea found in land features, climate and fossils
• Mid oceanic ridges are where the sea floor is spreading apart

Pangea in Action