Theory of Plate Tectonics

Power of Plate Motion

Chilean EarthquakeChile Quake Poses Possible Hawaii Tsunami Threat Major Earthquake in Hati 2010

A New Theory

Sea-floor spreading supported Wegener’s Continental DriftHow do we explain Sea-floor spreading and Continental Drift?Plate Tectonics

Plate Tectonics

Theory that the Earth’s lithosphere is divided into tectonic plates that move on top of the asthenospherePlate movement

Convection

Hot material rises while cool material sinksCool material is denseThe motion of sinking and rising material drags the tectonic plate away from mid-ocean ridgeFlash Presentation

Tectonic Plate Boundaries

ConvergentDivergentTransform

Convergent Plate Boundaries

When two plates push into each otherClassification based on crust:

Continental/ContinentalContinental/OceanicOceanic/Oceanic

Subduction Zones

Region where the oceanic plate sinks into the asthenosphereVolcanic formations frequently occurFormed at Convergent Boundary

Continental/oceanicOceanic/oceanic

Ocean Trenches

Divergent Plate Boundary

Two plate move away from each otherWhere new oceanic lithosphere formsCan form on land as well: rift valleyExample is mid-ocean ridge

Transform Plate Boundary

Two plates slide past each other horizontallySan Andreas Fault is example