Waveform inversion for D″ structure beneath northern Asia using Hi-net tiltmeter data

Kenji Kawai (1) , Shutaro Sekine , Nobuaki Fuji , Robert J. Geller

1 IPGP - Institut de Physique du Globe de Paris

We invert shear-wave waveform data for the radial variation of (isotropic) shear-velocity in D″ beneath Northern Asia. We reduce source and receiver effects by using data for intermediate and deep events beneath Italy and Japan recorded respectively at stations in East Asia and Europe. Relative to PREM, we find a significantly higher S-wave velocity in the depth range from 150 to 300 km above the core-mantle boundary (CMB) and a slightly lower S-wave velocity in the depth range 0-150 km above the CMB. As our previous studies of D″ structure beneath Central America and the Arctic obtained similar S-wave velocity models, we suggest that this pattern of vertical dependence of shear wave velocity in D″ may be a general phenomenon, at least in relatively cold regions.

Domaines: Planète et Univers [physics]

Kenji Kawai, Shutaro Sekine, Nobuaki Fuji, Robert J. Geller. Waveform inversion for D″ structure beneath northern Asia using Hi-net tiltmeter data. Geophysical Research Letters, 2009, 36, ⟨10.1029/2009GL039651⟩. ⟨insu-03604888⟩