Plate Tectonics

3 Pages 732 Words

Paper #1
Plate Tectonics is a theory proposed and accepted by scientists to explain the nature of earth’s surface characteristics and oceanic and continental makeup. Plate Tectonics divides the earth’s surface into separate sections known as lithospheric plates. These lithospheric plates are composed of the hard rigid outer crust of the earth which “float” on top of the hot more pliable asthenospheric layer. The heating of the asthenospheric layer by the lower mantle results in density changes causing a current type rotational motion which in turn drags the above plates. This motion and the floating attribute of the lithospheric plates gives rise to the earth’s changing surface and oceanic floor features. The behavior of the plates at their intersecting boundaries yields distinct geographical features dependent upon their composition and direction of movement. Divergent, convergent, and transverse are the three main labels associated with plate interactions at their boundaries. Divergent action results when plates are being pulled away from one another forming rifts and splitting open surfaces. Convergent movement results when plates collide and push together resulting in buckling and overall shortening. Transform boundaries result when two plates slide alongside each other creating fault lines but not actually increasing or decreasing overall crust material. Divergent and Convergent boundaries produce distinctive characteristics based upon the composition of the interacting plates.
The Ring of Fire describes a geographical area of intense volcanic and seismic activity and oceanic trenches outlining the Pacific Basin. Seventy-five percent of the world’s active and dormant volcanoes can be found in this arc stretching from New Zealand thru the eastern seaboard of Asia north to the Aleutian Islands and south following the coast of North and South America. This geological phenomenon was recognized long before it...