Seismological in situ Estimation of
Density Jumps across the Transition Zone Discontinuities beneath Japan
Mamoru Kato, and Hitoshi Kawakatsu
Geophys. Res. Lett., in press, 2001
Abstract
We investigate the magnitude of shear-wave velocity and
density jumps across the 410-km and 660-km discontinuities
in the Earth's mantle. We estimate SS reflection and PS
conversion coefficients from ScS reverberations and
receiver-side P-S converted phases, respectively, using
broadband seismograms recorded at stations in western
Japan. Fractional changes of model parameters that
satisfy our observations in the northwest Pacific are
(Delta Vs, Delta rho)= (8.5%, 5.4%) for
the 660-km discontinuity, and (4.9%, 1.9%) for
the 410-km discontinuity.