Plate tectonics and crustal deformation around the Japanese Islands
Plate tectonics and crustal deformation around the Japanese Islands
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日本列岛周围的板块构造和地壳变形
DOI：
10.1029/93jb00444
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发表时间：
1993
影响因子：
--
通讯作者：
D. Jackson
中科院分区：
文献类型：
--
作者：
M. Hashimoto;D. Jackson
我们分析了世纪以来的大地测量数据，使用Matsu'ura等人（1986）开发的地壳变形块断层模型研究日本列岛周围的地壳变形和板块运动。在该模型中，地壳形变是指块体间的相对运动和断层闭锁部位的位错沿着位移的总和。根据活动断层和地震活动的分布，我们模拟了包括日本列岛在内的19个地壳块体和104个断层的区域。使用了三种数据：角度和长度的变化率，以及甚长基线干涉测量站的平均速度。利用这些大地测量数据反演得到了块体运动和断层的平均滑动速率。该大地模型预测太平洋板块相对于欧亚板块以80 ± 3 mm/年的速度向N69° ± 2°W方向移动，比地质模型预测的速度低得多。在俯冲边界上发生了大量的地壳滑动。包含伊豆半岛的地块可能与菲律宾海板块的刚性部分分离。日本海沿岸和中央构造线西部的断层的滑动速率超过4 mm/年，而大窝在日本中部的构造中不起重要作用。大地测量模型要求划分日本东北部，与日本东北部是北美板块一部分的假设相反。南海海槽由于快速收敛，其地震危险性可能大于东海海隙。
We analyze over a century of geodetic data to study crustal deformation and plate motion around the Japanese Islands, using the block-fault model for crustal deformation developed by Matsu'ura et al. (1986). In this model, crustal deformation corresponds to the sum of relative movement among designated blocks and displacement due to dislocations along the locked parts of designated faults. We model the area including the Japanese Islands with 19 crustal blocks and 104 faults based on the distribution of active faults and seismicity. Three kinds of data are used; rates of change of angles and lengths, and average velocities of very long baseline interferometry stations. With the inversion of these geodetic data we obtain block motions and average slip rates of faults. This geodetic model predicts that the Pacific plate moves N69° ± 2°W at about 80 ± 3 mm/yr relative to the Eurasian plate which is much lower than that predicted in geologic models. Substantial aseismic slip occurs on the subduction boundaries. The block containing the Izu Peninsula may be separated from the rigid part of the Philippine Sea plate. The faults on the coast of Japan Sea and the western part of the Median Tectonic Line have slip rates exceeding 4 mm/yr, while the Fossa Magna does not play an important role in the tectonics of the central Japan. The geodetic model requires the division of northeastern Japan, contrary to the hypothesis that northeastern Japan is a part of the North American plate. Owing to rapid convergence, the seismic risk in the Nankai trough may be larger than that of the Tokai gap.