plate tectonics theory

Topics: Plate tectonics, Earth, Mid-ocean ridge Pages: 2 (447 words) Published: December 4, 2013

11/20/13
Earth Space Science
Plate Tectonics Theory
Plate tectonics is the theory that the outer rigid layer of the earth is divided into a couple of dozen plates that move around across the earth's surface relative to each other, like slabs of ice on a lake. Plate Tectonics is cause by convection currents in the mantle of the Earth. This theory was originally called continental drift. The theory of “Pangea” that is the continents were connected was Alfred Wegener. The age of the sea floor is one good piece of evidence that very adequately supports the theory of plate tectonics. The Ocean floor is around 160 million years old while the crust of the earth is around 3.8 billion years old. Another example is that the shapes of many continents are such that they look like they are separated pieces of a jig-saw puzzle. The fact that they are so properly shaped to fit together causes the plate tectonic theory to be properly supported by it. There is also large amount of seismic, volcanic, and geothermal activity along the conjectured plate boundaries. The concentration is striking, and indeed this plot serves to define the plate boundaries extremely well. The plotted earthquake and volcanic activity on the physiographic chart of the sea floor can be seen to follow along the plates, very few were far away from the plates. The earthquakes that were not close to the plate boundaries, like the one in England, was weaker and can be attributed to other reasons such as reduced weight stress from the melting of once glaciers that covered the area. The movement of the continents over a long period of time is measurable and has been done by many geologists. Another example is how there are ridges, such as the Mid-Atlantic Ridge where plates are separating that are produced by lava welling up from between the plates as they pull apart. Likewise, there are mountain ranges being formed where plates are pushing against each other such as the Himalayas, which are still...
Continue Reading

Please join StudyMode to read the full document

You May Also Find These Documents Helpful

  • plate tectonics Essay
  • the history of plate techtonics Essay
  • “What evidence is there to support Alfred Wegener’s theory of continental drift? Essay
  • Plate Tectonics Essay
  • Oceanography: Review Plate Tectonics Essay
  • Essay about Discuss the Degree to Which the Theory of Plate Tectonics Is Supported by the Distribution of Seismic Activity Across the Globe.
  • Plate Tectontics: an Essay
  • “Volcanic and Seismic Events Are Major Pieces of Evidence Towards Proving That the Plate Tectonic Theory Is Valid” Discuss the Extent to...

Become a StudyMode Member

Sign Up - It's Free