A Crustal Section across the Izu-Ogasawara Arc and Trench
A Crustal Section across the Izu-Ogasawara Arc and Trench
复制标题
横跨伊豆小笠原弧和海沟的地壳剖面
DOI：
10.4294/jpe1952.18.125
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发表时间：
1970
期刊：
影响因子：
--
通讯作者：
H. Hotta
中科院分区：
文献类型：
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作者：
H. Hotta
用地震折射和反射方法研究了伊豆-小笠原岛弧和海沟体系北部的地壳结构。给出了沿纬度32°N的岛弧和海沟的地壳剖面示意图。在海沟和七仁-岩岛脊之间的狭窄区域，与千岛弧及其南部与马里亚纳弧的交界处相同，检测到厚度为5.4 km/sec的层。如果5.4 km/s的地层与南侧29°N以南双弧的外弧形成有关，那么该地层的存在可能表明近期非火山外弧的延续，但未反映在北部的地形上。推断在海沟脊侧坡下存在一条下探至地幔的断裂。岛弧和海沟系统的力机制研究表明了这一断层，最近对浅深地震的空间分布和震源机制的研究也支持了这一断层。
The crustal structure across the northern part of the Izu-Ogasawara arc and trench system was investigated by seismic refraction and reflection methods. A schematic crustal section across the island arc and trench along latitude 32°N is presented. The 5.4-km/sec layer in appreciable thickness was detected in the narrow area between the trench and the Shichito-Iwojima ridge as same as in the Kuril arc and the southern part of this arc in the junction to the Mariana arc. If the 5.4-km/sec layer was concerned with the outer arc formation in the southern double arc, south of 29°N, then the presence of the layer may indicate the continuation of a recent non-volcanic outer arc not reflected on the topography to the north. There is inferred a fault which reaches down to the mantle under the ridge side slope of the trench. The fault is suggested by a study on the force mechanism in the island arc and trench systems and supported by a recent study on the spacial distribution and focal mechanisms of shallow to deep earthquakes.