Plate tectonics - Plate tectonics - Development of tectonic theory: The outlines of the continents flanking the Atlantic Ocean are so similar that their correspondence was apparent as soon as accurate maps became available. Plate tectonics definition is - a theory in geology: the lithosphere of the earth is divided into a small number of plates which float on and travel independently over the mantle and much of the earth's seismic activity occurs at the boundaries of these plates. Plate tectonics theory explains why: Earth’s geography has changed through time and continues to change today.
Movement of the plates over Earth’s surface is termed plate tectonics. Plate tectonics is a theory that was first proposed in the early 1900s by scientist Alfred Wegener, but was not said to be true until the 1960s. These huge land masses, referred to as plates, gradually change position relative to each other as they slide over underlying material. The theory of plate tectonics is a major cornerstone in the field of geology. some places are prone to earthquakes while others are not. Plate tectonics is the theory that the outer rigid layer of the earth (the lithosphere) 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. According to the theory of plate tectonics, the continents are not rigidly fixed to the surface of the Earth. A single plate can be made of all oceanic lithosphere or all continental lithosphere, but nearly all plates are made of a combination of both. Plate Tectonics Theory. Plates move at a rate of a few centimeters a year, about the same rate fingernails grow.

In consequence, the map of the Earth’s surface is constantly changing over geological timescales. The drawing above is a cross section of the earth showing the components that lie within plate tectonic theory. certain regions may have deadly, mild, or no volcanic eruptions. Plate tectonics is relatively new, put forth in the last 30 years or so — its forerunner was the now-discarded continental drift theory. Plate tectonics is the unifying theory of geology.