MODULATED THERMOCONVECTIVE WAVES IN THE EARTH'S LITHOSPHERE
Rubrics: ORIGINAL ARTICLES
Authors:
1.
Schmidt United Institute of Physics of the Earth, Russian Academy of Sciences, Moscow, Russia
Type:
Article
Pages:
from 137
to 150
Status:
Published
Received:
25.10.1998
Accepted:
25.10.1998
Published:
25.10.1998
Language:
English
Keywords:
thermoconvective waves, Earth's lithosphere, sediments, rheology of rocks.
Abstract (English):
For flows associated with small strains, the rheology of rocks is described by a linear integral having a memory law, which reduces to the Andrade law in the case of constant stresses. The continental lithosphere with such a rheology is overstable. Thermoconvective waves propagating through the lithosphere without attenuation have a period of about 200 Ma and a wavelength of the order of 400km. A pointwise perturbation of the initial temperature in the lithosphere excites amplitude-modulated thermoconvective waves wave packets. When the initial perturbation occupies a finite area, thermoconvective waves move outside from this area and thermoconvective oscillations standing waves are settled within the area. Thermoconvective waves induce oscillations of the Earth' surface, accompanied by sedimentation and erosion, and can be viewed as a mechanism for the distribution of sediments on continental cratons.
For flows associated with small strains, the rheology of rocks is described by a linear integral having a memory law, which reduces to the Andrade law in the case of constant stresses. The continental lithosphere with such a rheology is overstable. Thermoconvective waves propagating through the lithosphere without attenuation have a period of about 200 Ma and a wavelength of the order of 400km. A pointwise perturbation of the initial temperature in the lithosphere excites amplitude-modulated thermoconvective waves wave packets. When the initial perturbation occupies a finite area, thermoconvective waves move outside from this area and thermoconvective oscillations standing waves are settled within the area. Thermoconvective waves induce oscillations of the Earth' surface, accompanied by sedimentation and erosion, and can be viewed as a mechanism for the distribution of sediments on continental cratons.
Keywords:
thermoconvective waves, Earth's lithosphere, sediments, rheology of rocks.
thermoconvective waves, Earth's lithosphere, sediments, rheology of rocks.
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