A new configuration and an aseismic slab of the descending Philippine sea plate revealed by seismic tomography
A new configuration and an aseismic slab of the descending Philippine sea plate revealed by seismic tomography
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地震层析成像揭示了菲律宾海板块下降的新构造和抗震板
DOI：
10.1016/s0040-1951(01)00182-2
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发表时间：
2001
期刊：
影响因子：
2.9
通讯作者：
S. Sekiguchi
中科院分区：
文献类型：
--
作者：
S. Sekiguchi
利用区域地震台网记录的18年P相资料，通过走时层析成像方法，获得了菲律宾海板块下降的日本中部关东、东海和中部地区上地幔的三维地震速度结构。在关东地区下方发现了一个明显的低速带，它是菲律宾海板块下降的洋壳。低速带揭示了菲律宾海板块的一种新的结构，它不同于通过震源分布和震源机制分析所得到的任何模型。在关东和中部地区之间的火山锋面下方的深海区也发现了一个高速区。它延伸到菲律宾海板块在这两个地区。它很可能是菲律宾海板块的一个向东延伸的部分。在中部地区之下的东亚菲律宾海板块的存在得到了证实。在活火山下面还有一个低速区。高泊松比的地区被发现在火山和菲律宾海板块的低速带附近的火山前关东地区。
We obtained the three-dimensional seismic velocity structure of the uppermost mantle beneath the Kanto, Tokai and Chubu regions, central Japan, where the Philippine Sea plate descends, by means of travel time tomography using 18 years of P phase data recorded by a regional seismic network. A distinct low velocity zone, which was the oceanic crust of the descending Philippine Sea plate, was found beneath the Kanto region. The low velocity zone revealed a new configuration of the Philippine Sea plate different from any models obtained through the analysis of hypocenter distribution and focal mechanisms. We also found a high velocity area in the deep aseismic region below the volcanic front between the Kanto and Chubu regions. It extends to the Philippine Sea plate in both regions. It was likely to be an aseismic extended section of the Philippine Sea plate. The existence of the aseismic Philippine Sea plate beneath the Chubu region was confirmed. There was another low velocity area beneath the active volcanoes. High Poisson's ratio areas were found both beneath the volcanoes and in the low velocity zone of the Philippine Sea plate near the volcanic front under the Kanto region.