Open AccessSelf‐consistent generation of tectonic plates in time‐dependent, three‐dimensional mantle convection simulations
Author(s) -
Tackley Paul J.
Publication year - 2000
Publication title -
geochemistry, geophysics, geosystems
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.928
H-Index - 136
ISSN - 1525-2027
DOI - 10.1029/2000gc000036
Subject(s) - geology , mantle (geology) , convection , mantle convection , wavelength , mechanics , yield (engineering) , tectonics , plate tectonics , geophysics , toroid , geometry , lithosphere , seismology , optics , physics , thermodynamics , mathematics , plasma , quantum mechanics
Presented here are self‐consistent, three‐dimensional simulations of mantle convection, some of which display an approximation of plate tectonic behavior that is continuous in space and time. Plate behavior arises through a reasonable material description of silicate deformation, with a simple yield stress being sufficient to give first‐order plate‐like behavior; however, the required yield strength or fault frictional coefficient is much less than experimentally determined values. Toroidal:poloidal ratios are within geologically observed limits. The sensitivity of the system to yield strength and the form of strength envelope is systematically investigated. Optimum plate character is obtained in a narrow range of yield strength, below which diffuse boundaries, and above which episodic behavior, and eventually a rigid lid, are observed. Models with mobile lids develop very long wavelength horizontal structure, the longest wavelength possible in the domain. Two‐dimensional models display much greater time dependence than three‐dimensional models.