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Moho geometry and upper mantle images of northeast India
Author(s) -
Ramesh D. S.,
Ravi Kumar M.,
Uma Devi E.,
Solomon Raju P.,
Yuan X.
Publication year - 2005
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 - 10.1029/2005gl022789
Subject(s) - geology , classification of discontinuities , discontinuity (linguistics) , transition zone , mantle (geology) , seismology , crust , moho , receiver function , geometry , geophysics , lithosphere , tectonics , fungi imperfecti , mathematics , microbiology and biotechnology , biology , mathematical analysis
Images of the crust and mantle beneath northeast India obtained by 2D migration of ∼1000 broadband P‐receiver functions clearly trace a northward dipping Moho from the Himalayan foredeep reaching depths up to 50 km further north beneath the Himalayan convergence zone. Also, these images reveal presence of largely coherent 410‐km and 660‐km discontinuities that conform to the IASP91 model. Marginal variations in the depth of the 410‐km interface are observed, that appear region specific. The thickness of the mantle transition zone does not deviate significantly from a global average of ∼250 km. Interestingly, our results reveal consistent presence of a signal from an interface around 300 km. Origin of such a boundary, known as X‐discontinuity and unrelated to the Lehmann discontinuity, is discussed. Possible presence of the X‐discontinuity from the Indian region is reported here for the first time.