N. Erdogan et Rl. Nowack, SLANT-STACK VELOCITY ANALYSIS FOR ONE-DIMENSIONAL UPPER-MANTLE STRUCTURE USING SHORT-PERIOD DATA FROM MAJO, Pure and Applied Geophysics, 141(1), 1993, pp. 1-24
In this paper, regional P-wave upper mantle structure is investigated
using slant-stack velocity analysis of short-period earthquake data re
corded at station MAJO (Matsushiro, Japan). Shallow earthquakes from 1
980-1986 within 35-degrees of MAJO are used to construct a common rece
iver gather. Processing of the wavefield data includes focal depth and
static time corrections, as well as deterministic deconvolution, in o
rder to equalize pulse shapes and align wavelets on the first arrivals
. The processed wavefield data are slant stacked and iteratively downw
ard continued to obtain a regional upper mantle velocity model. The mo
del includes a low velocity zone between 107 and 220 km. Beneath the L
VZ, the velocity increases smoothly down to the discontinuity at 401 k
m. In the transition zone, the velocity model again increases linearly
, although there is some suggestion of further complexity in the downw
ard continued wavefield data. At the base of the transition zone, a se
cond velocity discontinuity occurs at 660 km, with a linear velocity g
radient below. In addition to slant-stack analysis, travel times and s
ynthetic seismograms are computed and compared with the processed and
unprocessed wavefield data.