伊豆-小笠原-马里亚纳俯冲带地震成因

发布时间：2018-03-03 16:55

本文选题：俯冲带　切入点：地震　出处：《海洋地质与第四纪地质》2017年04期 　论文类型：期刊论文

【摘要】：计算了伊豆-小笠原、马里亚纳弧段的浅源地震与俯冲速率的相关系数,证实了俯冲速率是一个重要的控制因素。地震统计结果展示马里亚纳中深度(60~300km)地震存在较明显分段性,且与海底地形起伏度相对应,推断这种现象一方面因为海山俯冲引起的板块破裂程度高,导致更多的流体供应所致;另一方面可能与海山俯冲机制导致板片局部变形有关。通过全球P波波速模型,提取马里亚纳之下大约8.0km/s的等值面,揭示了俯冲板片的深部形态,在马里亚纳弧的南北两侧之下,存在两个明显的缺失,代表了板片深部的撕裂,且北部撕裂程度要比南部高,可能与北部小笠原高原与南部卡罗琳洋中脊俯冲有关。重力数据与地震数据揭示了相对于马里亚纳俯冲带北部,南部可能为强耦合,菲律宾海板块之下410~660km不连续界面滞留为太平洋板片,西南部与马里亚纳俯冲带南部俯冲太平洋板片相连。初步推断这种结构与具有较大浮力的卡罗琳洋中脊可能共同决定了马里亚纳俯冲带南部8°N、137.3°E存在的旋转极。
[Abstract]:The correlation coefficients between shallow source earthquakes and subduction rates in the Yidou-Ogasawara and Mariana arcs are calculated. It is proved that the subduction rate is an important controlling factor. It is inferred that this phenomenon is due to the high rupture degree of the plate caused by seamounts subduction, which leads to more fluid supply. On the other hand, it may be related to the local deformation of the plate caused by the seamount subduction mechanism. By using the global P-wave velocity model, the isosurface of about 8.0 km / s below Mariana is extracted, which reveals the deep shape of the subduction plate. Below the north and south sides of the Mariana Arc, there are two obvious lacerations, which represent the deep tear of the plate, and the tear is higher in the north than in the south. Gravity data and seismic data suggest that the south may be strongly coupled to the north of the Mariana subduction zone. The discontinuous interface of 410m 660km below the Philippine Sea plate is trapped in the Pacific plate. The southwest is connected with the subduction Pacific plate in the south of the Mariana subduction zone. It is preliminarily deduced that this structure and the Carolyn mid-ocean ridge with greater buoyancy may jointly determine the rotation pole of 8 掳Ne 137.3 掳E in the south of the Mariana subduction zone.
【作者单位】：海底科学与探测技术教育部重点实验室中国海洋大学海洋地球科学学院;青岛海洋科学与技术国家实验室海洋地质功能实验室;
【基金】：国家自然科学基金杰出青年基金(41325009) 山东省泰山学者特聘教授项目国家重点研发计划(2017YFC0601400-1) 鳌山卓越科学家计划(2015ASTP-0S10)
【分类号】：P736.1;P738.4

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