Interplate coupling in the Tokai District, central Japan, deduced from continuous GPS data
Interplate coupling in the Tokai District, central Japan, deduced from continuous GPS data
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根据连续 GPS 数据推导出日本中部东海地区的板间耦合
DOI：
10.1029/1999gl900511
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发表时间：
1999
影响因子：
5.2
通讯作者：
T. Sagiya
中科院分区：
文献类型：
--
作者：
T. Sagiya
我反演了东海地区的GPS位移速率，以调查与预期的东海地震相关的应变积累。我应用了Savage[1983]提出的俯冲带地震间应变累积的表示法，估计了板块边界面上的虚拟正断层滑动(背滑)的分布。据估计，恩舒海下的背滑最大值为30-40毫米/年。这个值几乎等于那里的相对板块运动，意味着几乎完全耦合。苏鲁加湾以下的背滑较小，其方向与欧亚板块和菲律宾海板块之间的相对运动方向不同。菲律宾海板块北端的局部形变可能是造成这种差异的原因，板块会聚成伊豆半岛两侧断层所导致的构造应变被分割，同时也是分布在半岛内部的应变。
I invert GPS displacement rates in the Tokai district to investigate strain accumulation associated with the anticipated Tokai earthquake. I apply a representation of interseismic strain accumulation at subduction zones by Savage [1983] and estimate a distribution of virtual normal fault slip (back‐slip) on the plate boundary surface. Estimated back‐slip takes its maximum value of 30–40mm/year under the Sea of Enshu. This value is nearly equal to the relative plate motion there, implying almost complete coupling. Back‐slip is smaller under Suruga Bay, and its direction is different from the relative motion between the Eurasian and the Philippine Sea plates. Localized deformation at the northern tip of the Philippine Sea plate may be responsible for this discrepancy, partitioning tectonic strain due to the plate convergence into faults on both sides of the Izu peninsula and also distributed strain inside the peninsula.