Viscoelastic relaxation of lithospheric flexure and its influence on determining thickness of elastic lithosphere

doi:10.7523/j.issn.2095-6134.2020.05.008

Abstract

Abstract: It is of significant importance to determine the thickness of elastic lithosphere in geoscience. The traditional method of inverting the thickness of elastic lithosphere constrained by the location of peripheral bulge in the flexural lithosphere based on the analytical solution of elastic plate flexure has far-reaching influence. In this work, the viscoelastic relaxation of the lithosphere flexure under vertical surface loads is studied quantitatively by means of a compressible viscoelastic finite element model with variable viscosities. The simulation results show that the position of the peripheral bulge moves first to the bending center and then to the outside of the bending, and the reverse motion occurs about 9 Ma after the loading. Compared with the elastic lithospheric thickness defined by relaxation time, the method of determining the thickness of the elastic lithosphere by the position of the peripheral bulge based on elastic plate bending solution gives reasonable results only in the period of 0.2-5.0 Ma after loading.

Key words: lithospheric flexure, elastic lithosphere, viscoelastic relaxation, numerical simulation

CLC Number:

SHAO Cuifa, WANG Shimin. Viscoelastic relaxation of lithospheric flexure and its influence on determining thickness of elastic lithosphere[J]. , 2020, 37(5): 640-649.

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