An examination of tectonics, trenches, ridges, seawater composition, topography and continental shelves.
The Sea Floor
The birth and death of oceans is a continuous process. As an example, one ocean may be growing by sea-floor spreading from a mid-ocean ridge while another ocean is closing because of the continents forcing the ocean floor down at the trenches. Some oceans, thus, are young and growing, while other oceans have reached maturity, and still others may be disappearing with the joining of the continental masses [1:1-7].
The birth and death of oceans is a continuous process. As an example, one ocean may be growing by sea-floor spreading from a mid-ocean ridge while another ocean is closing because of the continents forcing the ocean floor down at the trenches. Some oceans, thus, are young and growing, while other oceans have reached maturity, and still others may be disappearing with the joining of the continental masses [1:1-7].
The theory of plate tectonics envisages the crust of the earth together with the upper part of the mantle, which form the lithosphere, as consisting of rigid slabs, or plates, that are continuously moving their position in relation to one another. Below the lithosphere is the asthenosphere, which is thought to be plastic [2:1-11].
The plates are…