Plate TectonicsEnvironmental Science

Plate TectonicsThe Earth Inside Out

Bathymetry and Seafloor MappingThe Theory of Continental Drift

Lab continental drift

Seafloor SpreadingLab seafloor spreading

Plate TectonicsLab plate tectonics

Earth’s Internal LayersHow do we classify the Earth’s internal layers?How is the lithosphere different from the crust?

Layers of the Earth

Composition, Density and Temp.Core: Nickel (Ni), Iron (Fe) and other heavy

elementsInner core and outer core same temperature

however massive pressure and density keeps inner core solid

Mantle: mostly Silicon (Si) and Oxygen (O)Lower density than coreLower mantle is solid, upper mantle is “plasticy”

Lithosphere and Asthenosphere

Lithosphere and AsthenosphereLithosphere = Crust and upper part of upper

mantleAsthenosphere = lower part of upper mantleLithosphere “floats” on asthenosphere

Rock CycleWhat are the three types of rock? How does the

rock cycle account for their formation?

Isostatic EquilibriumHow does Archimedes Principle relate to the

structure of the Earth?What is isostatic equilibrium?What links some earthquakes with isostatic

equilibrium? Where do such earthquakes occur?

Archimedes Principle

Archimedes Principle

Isostatic Equilibrium

IsostasyThe lithosphere floats

on the asthenosphere The various portions of

the Earth’s crust reach gravitational equilibrium

Due to variations in thickness and density, some crustal blocks ride higher than others

Isostatic ReboundIsostatic Equilibrium is the balance between

the weight of the lithosphere and the buoyant force of the asthenosphere

Isostatic Rebound is when compensation occurs from an increase or decrease of lithospheric weight…causing earthquakes along weak areas called - faults

Onto the Festivities!!!

Alfred Wegner and Continental DriftWhat is Pangea and Panthalassa?What is the theory of continental drift?What evidence did Wegner use to support his

theory?Why didn’t scientists support his theory? What

further evidence could have strengthened his theory?

Pangea

Panthalassa

Wegner’s TheoryPangea: big supercontinentPanthalassa – Ocean surrounding PangeaWegner theorized that because the less dense

continents floated on the more dense matle, Pangea broke apart into separate pieces.

Theory of Continental Drift

The EvidencePieces fit together like a puzzle

Fossil Distribution

Accepted Theory? I Think Not!Good evidence but no go for public acceptance.Possibly because Alfred was a meteorologist not a

geologistTo many gaps between continentsHe disappeared on an expedition in 1930 in

GreenlandLater on, plate tectonics theory described how the

gaps between the continents were continental shelves

O.k. Let’s Check It Out

Pangea Lab!!!!Oooooh Yeah Baby!