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, wh... More »

Andrew Alden of About explains that Australian geologist Sam Carey's theory of Earth expansion, the idea that the continents fit together properly only on a formerly smaller Earth, once rivaled the theory of plate tecton... More »

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 mantl... More »

www.reference.com Science Earth Science Plate Tectonics

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 mantl... More »

www.reference.com Science Earth Science Plate Tectonics

The theory of plate tectonics, formerly known as continental drift, is a working model that describes the movement of the continents and sea floor across the surface of the Earth. The theory explains many anomalous facts... More »

Andrew Alden of About explains that Australian geologist Sam Carey's theory of Earth expansion, the idea that the continents fit together properly only on a formerly smaller Earth, once rivaled the theory of plate tecton... More »

According to About.com, the Earth creates mountains through plate tectonics, where its crust is broken into plates constantly in motion, causing stress and uplifting in order to grow mountains. While growth is slow due t... More »