Imaging the lithospheric structure beneath the Indian continentстатья
Статья опубликована в высокорейтинговом журнале
Информация о цитировании статьи получена из
Web of Science,
Scopus
Статья опубликована в журнале из списка Web of Science и/или Scopus
Дата последнего поиска статьи во внешних источниках: 30 марта 2018 г.
Авторы:
Maurya S.,
Montagner J.P.,
Ravi Kumar M.,
Stutzmann E.,
Kiselev S.,
Burgos G.,
Purnachandra Rao N.,
Srinagesh D.
Аннотация:We present a high-resolution 3-D lithospheric model of the Indian plate region down to 300 km
depth, obtained by inverting a new massive database of surface wave observations, using classical
tomographic methods. Data are collected from more than 550 seismic broadband stations spanning the
Indian subcontinent and surrounding regions. The Rayleigh wave dispersion measurements along ~14,000
paths are made in a broad frequency range (16–250 s). Our regionalized surface wave (group and phase)
dispersion data are inverted at depth in two steps: first an isotropic inversion and next an anisotropic
inversion of the phase velocity including the SV wave velocity and azimuthal anisotropy, based on the
perturbation theory. We are able to recover most of the known geological structures in the region, such as the
slow velocities associated with the thick crust in the Himalaya and Tibetan plateau and the fast velocities
associated with the Indian Precambrian shield. Our estimates of the depth to the Lithosphere-Asthenosphere
boundary (LAB) derived from seismic velocity Vsv reductions at depth reveal large variations (120–250 km)
beneath the different cratonic blocks. The lithospheric thickness is ~120 km in the eastern Dharwar, ~160 km
in the western Dharwar, ~140–200 km in Bastar, and ~160–200 km in the Singhbhum Craton. The thickest
(200–250 km) cratonic roots are present beneath central India. A low velocity layer associated with the
midlithospheric discontinuity is present when the root of the lithosphere is deep.