Plate+Tectonics-Mechanism

Austin and Justin Mrs. Fretz Blue Class June 2007 media type="youtube" key="X9lOcm_CcBQ" Plate Tectonics Mechanism



Basics- Crustal movement beneath the earth's surface causes volcanos, earthquakes, mountians and tsunami's. The plates float on the asthenosphere and they may collide. When an oceanic plate meets a continental plate the oceanic plate is subducted because it is denser then the other and it falls underneath causing various effects including earthquakes and other natural disasters.

Continental Drift theory- Discoverd by a German philosopher named Alfred Wegner. 200 million years super continent named Pangea began moving apart. Pangea once combining all the land on earth began moving away creating the new continents and the current world we live in today. This is all found in our Plate Tectonics Lab.

The mechanism that allowed pangea to break up was convection currents of hot magma in Earth's Mantle. The convection currents break through the crust in the mid-oceanic ridges. New crust spreads out from the ridges and moves the plates. That is continental drift.

An example of a converging boundary, where land hits land, is where India slammed into Eurasia, which made the himalayan mountains. But as the continents moved apart the mountians remained and is now spread across three continents. This information can be found in greater detail on our plate tectonics lab.

Polar Wondering- Throughout history the earths magnetic poles have moved and reversed many times. This happens because the magnetic allignment of lava changes and therefore changes the poles. The lava flow always point at the magnetic poles. Even if the continents stay in place like nowadays, the poles are still subjuct to change. But the lava flows are greatly influenced by the earth's plates. Tsunami- Although we did not learn alot about tsunami's and other natural disaters caused by plate tectonics, tsunamis have affected our modern world and are important. Tsunami's are caused like earthquakes when one plate slips under another and a ridge is formed. The water comes to fill the ridge which creates a vacuum effect and causes the massave wave to head out of the ocean and on to possiably onto land.