|
Forces that Drive Tectonic Plate Motion
 | | Earth's mantle convection. Figure source: http://pubs.usgs.gov/publications/text/unanswered.html |
The motion of tectonic plates, together with the flow of the underlying asthenosphere, is part of a system of convection that is the principal way in which the Earth looses heat. (Part of this heat is produced by decay of radioactive elements within the Earth, the other part is left over from formation of the Earth, 4.5 billion years ago). A series of convection cells circulate by the slow movement of the hot, softened mantle that lies below the lithosphere, in turn pushing and pulling the plates in a conveyor belt-like motion. This idea was first considered in the 1930's by an English geologist named Arthur Holmes. Nonetheless, at that time it was thought that the Earth was solid and motionless and these ideas were generally accepted until the advent of plate tectonics in the 1960's.
|
