Seismicity around the trench axis and outer-rise region of the southern Japan Trench, south of the main rupture area of the 2011 Tohoku-oki earthquake
Seismicity around the trench axis and outer-rise region of the southern Japan Trench, south of the main rupture area of the 2011 Tohoku-oki earthquake
复制标题
2011 年东北冲地震主要破裂区以南的日本南部海沟外隆区和海沟轴周围的地震活动
DOI：
10.1093/gji/ggab093
复制
发表时间：
2021
影响因子：
2.8
通讯作者：
Kodaira Shuichi
中科院分区：
文献类型：
--
作者：
Obana Koichiro;Fujie Gou;Yamamoto Yojiro;Kaiho Yuka;Nakamura Yasuyuki;Miura Seiichi;Kodaira Shuichi
2011年Mw9.0级东北冲地震使日本海沟中部的俯冲断层破裂。我们调查了余震活动在日本南部海沟南部的主要破裂区使用洋底地震仪部署在向陆和向海的海沟。在海沟轴向海的海沟外隆起区，我们确定了几个100公里长的线性地震趋势，平行和倾斜的日本南部海沟。斜向南日本海沟的地震趋势是日本海沟中部至北方的平行海沟线性地震趋势向南的延伸。在主破裂区以南，尽管海沟走向由N-S向转变为NNE-SSW向，但海沟外隆起区的平行海沟正断层仍可以线性延伸。斜向海沟的正断层应被认为是大型板内正断层地震的重要组成部分。此外，板内地震活动与低速海洋地幔相吻合，表明结构的不均匀性将指示正断层延伸到地幔中。在海沟向陆区，地震活动表现出沿海沟的变化。在37°N以南观测到了沿着海沟附近的浅层巨型逆冲断层界面的地震。这些位于幕式地震附近并与地震活动时间相关的浅源近海沟规则地震表明，板块界面上的后滑可能延伸到靠近海沟轴的浅源板块界面。较小的空间尺度的结构不均匀性，如在通道状低速沉积单元的厚度变化，可能与附近的定期地震和缓慢的滑动，导致在浅俯冲带的日本海沟南部的不同的滑动行为的形成。
The 2011Mw9.0 Tohoku-oki earthquake ruptured the subduction megathrust fault in the central Japan Trench. We investigated the aftershock activity in the southern Japan Trench to the south of the main rupture area using ocean bottom seismographs deployed both landward and seaward of the trench. In the trench-outer rise region seaward of the trench axis, we identified several ∼100-km-long linear earthquake trends both parallel and oblique to the southern Japan Trench. The earthquake trend oblique to the southern Japan Trench is a southward extension of the trench-parallel linear earthquake trend in the central to northern Japan Trench. The trench-parallel normal-faults in the trench-outer rise region could extend linearly, despite the change of the trench strike from N–S to NNE–SSW to the south of the main rupture area. Normal-faults oblique to the trench should be considered as substantial parts of large intraplate normal-faulting earthquakes. In addition, intraplate seismicity coinciding with the lower velocity oceanic mantle suggest that the structure heterogeneity would be indicative of normal-faults extending into the mantle. In the trench landward area, earthquake activity showed along-trench variations. Earthquakes along the shallow megathrust interface near the trench were observed south of 37°N. These shallow near-trench regular earthquakes, which are located close to the episodic tremors and temporally correlated with the tremor activities, suggest that the afterslip on the plate interface likely extended to the shallow plate interface close to the trench axis. Smaller spatial scale structure heterogeneity, such as the thickness variation in the channel-like low-velocity sedimentary unit, likely relate to the proximity of the regular earthquakes and slow slip which results in the formation of diverse slip behaviours in the shallow subduction zone of the southern Japan Trench.
登录
查看更多内容
影响因子：
16.6
作者：
Agata, Ryoichiro;Barbot, Sylvain D.;Hori, Takane
通讯作者：
Hori, Takane
使用海底地震仪进行长期观测茨城县附近日本海沟临海斜坡的地震活动
DOI：
10.4294/zisin.62.19
发表时间：
2009
期刊：
Journal of the Seismological Society of Japan
影响因子：
--
作者：
M. Mizuno;Toshinori Sato;M. Shinohara;K. Mochizuki;Tomoaki Yamada;T. Kanazawa
通讯作者：
T. Kanazawa
DOI：
10.1007/978-90-481-8885-7_1
发表时间：
2011-01-01
期刊：
ACCRETIONARY PRISMS AND CONVERGENT MARGIN TECTONICS IN THE NORTHWEST PACIFIC BASIN
影响因子：
--
作者：
Nakanishi, Masao
通讯作者：
Nakanishi, Masao
影响因子：
18.3
作者：
Sun, Tianhaozhe;Saffer, Demian;Ellis, Susan
通讯作者：
Ellis, Susan
俯冲海洋板块的弯曲及其对日本宫城县附近日本海沟俯冲带大型板间地震破裂传播的影响
影响因子：
5.2
作者：
A. Ito;G. Fujie;S. Miura;S. Kodaira;Y. Kaneda;R. Hino
通讯作者：
R. Hino