Open AccessInversion of multimode surface wave data: evidence for sub‐lithospheric anisotropy
Author(s) -
Lévêque JeanJacques,
Cara Michel
Publication year - 1985
Publication title -
geophysical journal of the royal astronomical society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.302
H-Index - 168
eISSN - 1365-246X
pISSN - 0016-8009
DOI - 10.1111/j.1365-246x.1985.tb04336.x
Subject(s) - transverse isotropy , anisotropy , geology , lithosphere , inversion (geology) , isotropy , a priori and a posteriori , geophysics , geometry , seismology , optics , physics , mathematics , tectonics , philosophy , epistemology
Summary. Multiparameter inversions of multimode dispersion data are performed for two large regions: the Pacific Ocean and North America. Anisotropy is taken into account by considering transversely isotropic structures with a vertical axis of symmetry. Two fundamental questions are studied in detail: (1) how to make the inverted models consistent when using different sets of parameters, (2) what is the significance of transversely isotropic inversion for the actual Earth's structure? It is proved that full consistency of the inverted models can be achieved by properly taking into account some a priori informations on the model and it is shown that the use of transversely isotropic models with vertical axis of symmetry does not cause severe limitations when interpreting the data. The models we have obtained are discussed in the light of these investigations. Considering an olivine‐rich upper mantle, we make a tentative interpretation of these models in terms of preferred orientation of the a ‐axis of the crystals in one fixed horizontal direction.