Premium
Complex images of Moho and variation of Vp/Vs across the Himalaya and South Tibet, from a joint receiver‐function and wide‐angle‐reflection approach
Author(s) -
Galvé A.,
Sapin M.,
Hirn A.,
Diaz J.,
Lépine J.C.,
Laigle M.,
Gallart J.,
Jiang M.
Publication year - 2002
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 - 10.1029/2002gl015611
Subject(s) - geology , lithosphere , receiver function , seismology , crust , plateau (mathematics) , mantle (geology) , reflection (computer programming) , geodesy , joint (building) , geophysics , tectonics , architectural engineering , mathematical analysis , mathematics , computer science , engineering , programming language
Teleseismic receiver functions (RF) allow us to image the spatial variation of the crust‐mantle boundary (Moho) along a tight array spanning from south of the Himalayas to the centre of the Tibetan Plateau. This approach is cross‐tested with wide‐angle reflection imaging (WARR). Highlighted by each of the two independent methods, a complex architecture of the Moho with dipping and overlapping segments indicating lithospheric imbrication, is confirmed. The joint use of the two methods reveals an increase of the average crustal P‐to‐S‐wave‐velocity ratio from south to the centre of the Lhasa block. This may be due to lowered S‐wave velocity confined in specific layers, that may be interpreted as partial melt. This accounts for half of the relative increase in the delay of direct teleseismic S‐wave arrivals with respect to P‐wave arrivals from south to north, suggesting a similar anomaly in the shallower mantle.