Receiver function migration image of the deep structure in the Bohai Bay Basin, eastern China

Abstract

We apply a receiver function poststack migration method to image the crustal and upper mantle structures beneath the Bohai Bay Basin, eastern China. The thick sediments of the basin appear to have a substantial influence on the migrated image of the deep structure. By using the surface reflected PpPs multiples instead of the commonly used Ps converted phases, a curved Moho is coherently imaged, showing a thinned crust of ∼30 km in the basin area compared with the >40‐km thick crust in the west mountain range. By incorporating the sedimentary velocity model into migration, both the 410‐km and the 660‐km discontinuities present a simple structural feature with relatively flat topography within the basin's interior, although possible local structural complexities may exist at the base of the upper mantle around the boundary areas of the basin. The mantle transition zone is on average 10–15 km thicker than the global average, reflecting a cold lower upper mantle environment that is distinct from the warm shallow upper mantle of the region.