lithosphere

lithosphereThe lithosphere is the rigid, rocky outer layer of Earth, made up of the crust and the solid outermost layer of the upper mantle that extends a depth of about 60 miles (100 km).

lithosphere, rigid, rocky outer layer of Earth, consisting of the crust and the solid outermost layer of the upper mantle. It extends to a depth of about 60 miles (100 km). It is broken into about a dozen separate, rigid blocks, or plates (see plate tectonics).

crustal generation and destruction
crustal generation and destructionThree-dimensional diagram showing crustal generation and destruction according to the theory of plate tectonics; included are the three kinds of plate boundaries—divergent, convergent (or collision), and strike-slip (or transform).

A series of forces that include slab pull (the sinking of dense blocks into the underlying mantle), slow convection currents deep within the mantle (which are generated by radioactive heating of the interior) and ridge pushing (generated by the upwelling of mantle at divergent boundaries [such as oceanic ridges]) are believed to cause the lateral movements of the tectonic plates (and the continents that rest on top of them) at a rate of several inches per year.

The Editors of Encyclopaedia BritannicaThis article was most recently revised and updated by John P. Rafferty.
Citation Information
Article Title: lithosphere
Website Name: Encyclopaedia Britannica
Publisher: Encyclopaedia Britannica, Inc.
Date Published: 15 February 2025
Access Date: February 20, 2025