Complex structure of the mantle discontinuities at the tip of the
subducting slab beneath the northeast China:
a preliminary investigation of broadband receiver functions,
Fenglin Niu, Hitoshi Kawakatsu
J. Phys. Earth, (J-array special issue), 44, 701-711, 1996.
Abstract
Broadband seismic waveform data recorded at stations
in the western Pacific region are analyzed to investigate
the mantle discontinuities.
By using teleseismic deep events, we observe unambiguous
P-to-S conversion waves associated with the mid-mantle discontinuities
in many of the individual seismograms.
The commonly-used method of stacking receiver functions is not so effective
in the present circumstance due to the limited number of deep events.
An inversion scheme is developed to determine a discontinuity response function
at each station by fitting observed waveform data
with a superposition of the P-to-S converted waves.
Beneath the station in the northeast China (MDJ)
where the subducted Pacific plate appears to stagnate
along the `660-km' discontinuity,
the discontinuity response function has more complicated features
than those of other stations.
The preliminary result indicates no
depression of the `660-km' discontinuity at the tip of the subducting
slab beneath MDJ; instead a multiple-discontinuity structure down to
a depth of 780 km is observed.