Plate Tectonics
In 1911, Afred Wegener proposed the Theory of Continental Drift. It was not widely accepted since the technology at the time could not support the research neccessary to collect the data. After World War II, J. Tuzo Wilson proposed the Theory of Plate Tectonics. The technology developed for the war was used to map the ocean floors. This gave scientists valuable insights into the workings of the earth. Scientists continue to monitor earthquake and volcanic activity, explore the fossil record, study the rocks of the earth's crust, and map the earth's surface. Early in 2000, NASA launched an ambitous mapping activity using the space shuttle. Data collected from space will be used to generate the most comprehensive and accurate topographic maps of the earth ever produced. A link will be created here in the future as that information becomes public.
The forces driving plate movement are being studied. The diagram shows one theory of movement over convection currents in hot magma.
For a thorough and fascinating discussion of plate tectonics, visit the USGS website The Dynamic Earth, the original source of these graphics.
The illustration below shows the movement of the continents from the Permian Period of the Paleozoic Era to now. The original source of this is the USGS website.
For more images, go to Break-up of Pangaea You will be exiting this page. Use your browser back button to return.
For animations showing the position of continents througout geologic time, try Geology
Tectonics This is a PBS website with great interactive demonstrations of plate tectonics. You need shockwave to fully experience the effects.
Continents is another Nova site that's well worth the trip.
For follow-up information regarding the NOVA video "Garden of Eden", visit Eden. Click on the various pages. The one about island building has an animation showing the formation of the atolls.
Another great site to visit for an overview of everything from crust to tsunamis visit Savage Earth, a PBS website.
