岡山大学 地球科学研究報告
Published by Okayama University Earth Science Reports Editorial Committee

S-wave velocity structure estimated from long-period coda waves

Ito Aki
Abstract
Long-period coda waves were recorded on the vertical-component seismograms of aftershocks of the Hyogo-ken Nanbu earthquake, 1995. We identify the long-period coda waves as Rayleigh wave, because they appear after the S-arrival times and exhibit the normal dispersion that propagation velocity of the coda waves increases with an increase in period. By applying the moving window analysis to the coda waves from nine aftershocks, the group velocities are determined as a function of period within the range of 2 to 8 s. The group velocity dispersion data are inverted to investigate the S-wave velocity structure of the upper crust. The S-wave velocity structure is consistent with those obtained in previous studies using traval time analysis of bood waves.
Keywords
surface wave dispersion
coda wave
S-wave velocity structure
upper crust
Hyogo-ken
ISSN
1340-7414
NCID
AN10506284