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The role of hot uprising plumes in the initiation of plate‐like regime of three‐dimensional mantle convection
Author(s) -
Yoshida Masaki,
Ogawa Masaki
Publication year - 2004
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/2003gl017376
Subject(s) - lithosphere , asthenosphere , geology , convection , geophysics , viscosity , mantle convection , lithospheric flexure , plate tectonics , mantle (geology) , stress (linguistics) , newtonian fluid , mechanics , mantle plume , materials science , seismology , tectonics , physics , composite material , linguistics , philosophy
Three‐dimensional numerical models are presented for thermal convection of non‐Newtonian fluid with viscosity that depends on temperature and stress to understand development of moving plates on the Earth. A hysteresis is assumed in the relationship between stress and viscosity to make the viscosity depend on stress‐history. The stress‐history dependence due to hysteresis induces a regime where plates or highly viscous pieces of lithosphere separated by narrow and mechanically weak plate margins rigidly move by their own weight. The plate margins newly develop when a stress high enough to cause lithospheric rupture is induced in the lithosphere by the help of hot cylindrical uprising plumes but do not spontaneously develop by the weight of lithosphere itself. The high rupture strength of lithosphere makes the plate‐like motion rather steady without the help of viscosity reduction by melting in the asthenosphere.