Each continent is embedded onto plates, which are made from lithospheres - Earth's outermost layer. Because this layer is stronger than the underlying layer, it is able to move. Several forces encourage it to do this, which means Earth's landmass remains the same, but the location of continents shifts slightly each year.Know More
The plate tectonics theory first developed in the 1960s and 1970s as a means of explaining why Earth's continents have moved throughout history. It states that the layer underpinning the continents, the lithosphere, is able to move. This occurs when the seafloor's motion creates drag, and when it generates a downward suction. Another theory is that the sun and the moon generate tidal forces that encourage it to move.
The movement from plate tectonics is fairly minimal, at a rate of 0 to 100mm per year. The lithospheres are made of seven primary areas, as well as some minor regions. Sometimes the plates are able to move past each other, but at other times they crash, giving rise to events like earthquakes. In addition, crashing plates can cause volcanic eruptions and the development of mountains. While it is not always dangerous to live on or near a plate boundary, some areas do experience more earthquakes as a result.Learn more about Plate Tectonics
According to the Physics Department of the University of Tennessee Knoxville, evidence for plate tectonics has been found by studying continental shapes and comparing fossils. It notes that modern evidence for plate tectonics is much stronger than when it was first offered as a theory.Full Answer >
Very slow currents in the relatively plastic lower mantle, or aesthenosphere, are thought to push the crustal plates along and drive the process of plate tectonics. These currents are caused by convection, with the mantle rock being heated from below via radioactive decay and thus becoming less dense than the rock above. These hotter rocks move slowly upward, displacing the rock above and forcing it down in an elliptical motion.Full Answer >
Plate tectonics is primarily caused by Earth's cooling mechanism, which generates convection currents in the planet's mantle that trigger slow but constant tectonic plate movement. This phenomena occurs on the boundaries of adjacent plates, which are classified as divergent, convergent and transform boundaries.Full Answer >
Researcher Alfred Wegener developed the continental drift theory that led to the modern theory of plate tectonics. Because plate tectonics is still a theory, it is hypothesized and not officially discovered or proven.Full Answer >