摘要
The SdP, pdP and sdP phases are picked up with the Nth root slant stack method from the digital waveform data recorded by the networks and arrays in USA, Germany and Switzerland for the earthquakes occurring beneath Izu-Bonin and Japan Sea. The mantle discontinuities and the effects of subducting slab on the 660 km and 410 km discontinuities are studied. It is found that there are mantle discontinuities existing at the depths of 170, 220, 300, 410, 660, 850 and 1150 km. Beneath Izu-Bonin, the 410 km discontinuity is elevated, while the 660 km discontinuity is depressed; for both discontinuities, there are regionalized differences. Beneath Japan Sea, however, there is no depth variation of the 410 km discontinuity, and the 660 km discontinuity is depressed without obvious effect of the subducting slab.
The SdP, pdP and sdP phases are picked up with the Nth root slant stackmethod from the digital waveform data recorded by the networks and arrays in USA, Germany andSwitzerland for the earthquakes occurring beneath Izu-Bonin and Japan Sea. The mantlediscontinuities and the effects of subducting slab on the 660 km and 410 km discontinuities arestudied. It is found that there are mantle discontinuities existing at the depths of 170, 220, 300,410, 660, 850 and 1150 km. Beneath Izu-Bonin, the 410 km discontinuity is elevated, while the 660 kmdiscontinuity is depressed; for both discontinuities, there are regionalized differences. BeneathJapan Sea, however, there is no depth variation of the 410 km discontinuity, and the 660 kmdiscontinuity is depressed without obvious effect of the subducting slab.
基金
the National Natural Science Foundation of China(Grant No.49874020)
the Ph D Programs Foundation of Ministry of Education of China(Grant No.99000108).
