We use 1-D thermal history models and 3-D numerical experiments to study the impact of dynamic thermal disequilibrium and large temporal variations of normal and shear stresses on the initiation of plate tectonics. Previous models that explored plate tectonics initiation from a steady state, single plate mode of convection concluded that normal stresses govern the initiation of plate tectonics,...

The realization that Earth may have lost heat more slowly in the past than at present has motivated the search for mechanisms to reduce the efficiency of plate tectonics in the past. Several mechanisms have been proposed, such as the resistance to subduction of thick plates (1) produced by deeper melting at higher mantle temperatures (2). We (3) proposed an alternative mechanism, namely subduct...

erosion phenomenon (plate tectonics process) CESA'98 Nabeul-Hammamet, Tunisia, April 1998 Thomas LEDUC September 1997

The Earth stands out in the solar system as the only planet with plate tectonics. This peculiarity is due not only to strong internal heating but also a lithosphere rheology characterized by brittle failure and localization, as a comparison with Venus clearly show. Localization in the ductile regime are manifested on Earth by ductile shear zones, which have proven difficult to explain theoretic...

EARTHQUAKE SOURCE PARAMETERS, SEISMICITY, AND TECTONICS OF THE OCEANOGRAPHER TRANSFORM FAULT

The Earth Materials Area is comprises the Experimental Petrology, Rock Physics, Thermochronology and Structure & Tectonics Groups. The research of these groups centres around laboratory based measurements under controlled conditions, simulating those occurring in nature, but these activities are complimented by field based observations, often in collaboration with scientists from other institut...