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Elastic thickness of the Venus lithosphere estimated from topography and gravity
Author(s) -
Cazenave Anny,
Dominh Kien
Publication year - 1981
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/gl008i010p01039
Subject(s) - lithosphere , geology , venus , isostasy , gravity anomaly , lithospheric flexure , subduction , ridge , longitude , seismology , geophysics , mantle (geology) , asthenosphere , latitude , crust , geodesy , tectonics , astrobiology , paleontology , physics , oil field
The very close correlation observed on Venus between topography and gravity on a regional scale is clearly related to the isostatic compensation of the topographic loads. Observed gravity anomalies over topographic features of moderate lateral extent, located in the equatorial region (0° to 40° N latitude and 10° W to 60° E longitude) are somewhat larger than those computed with a model of local isostatic compensation (of Airy type). They may rather be explained by a model of compensation including elastic forces within the lithosphere which contribute to support topographic loads through elastic stresses. We have applied the theory of lithospheric flexure : to explain in wavelength and in amplitude the observed gravity anomalies, a flexural rigidity of ∼ 4 × 10 28 dyne cm has been estimated for the Venus lithosphere in the rolling plains province. This value is very low compared to the oceanic terrestrial lithosphere (ranging from ∼ 10 28 dyne cm near ridge crests to ∼ 2 × 10 31 dyne cm near subduction zones). The corresponding thickness of the elastic upper layer able to maintain elastic stresses for long time duration is ∼ 7.5 km. This value may not be representative of the entire Venus lithosphere.