Receiver Function Imaging of the Amphibious NE Japan Subduction Zone—Effects of Low‐Velocity Sediment Layer
Receiver Function Imaging of the Amphibious NE Japan Subduction Zone—Effects of Low‐Velocity Sediment Layer
复制标题
DOI：
10.1029/2021jb021918
复制
发表时间：
2021-08
期刊：
影响因子：
--
通讯作者：
Hyejeong Kim;H. Kawakatsu;T. Akuhara;M. Shinohara;H. Shiobara;H. Sugioka;R. Takagi
中科院分区：
文献类型：
--
作者：
Hyejeong Kim;H. Kawakatsu;T. Akuhara;M. Shinohara;H. Shiobara;H. Sugioka;R. Takagi
本文研究了日本东北（NE）俯冲带连续跨洋、跨陆的反射率图像。由于其近一半的前弧区域位于海洋之下，因此必须利用海底地震仪（OBSs）的数据进行被动地震分析，以对该区域进行全面成像。由于海底观测的固有特征：高噪声水平和海底沉积物的影响，OBS数据的使用一直是一个挑战。现在，在日本东北部，由于obs积累的数据集造成的高水平噪声，可以实现良好的成像。海底沉积物的低速极大地延迟和放大了穿过它们的S波，从而使远震波形变得复杂。我们识别和纠正这些影响，以在整个两栖俯冲带产生相干的接收函数图像。我们的图像为讨论新的构造特征提供了可能，并将有助于更好地理解日本东北部俯冲带的动力学。
This study presents reflectivity images of the northeast (NE) Japan subduction zone continuous across the ocean and land. As nearly half of its forearc region is under the ocean, data from ocean bottom seismometers (OBSs) must be utilized to fully image the region by passive seismic analysis. The use of OBS data has been a challenge due to inherent characters of the ocean bottom observations: high noise level and effects of seafloor sediment. Now, decent imaging is possible in NE Japan overcoming the high level noise due to the accumulated data set of the OBSs. The low‐velocity of seafloor sediment significantly delays and amplifies S waves passing through them, and thus complicates teleseismic waveforms. We identify and correct these effects to produce coherent receiver function images throughout the amphibious subduction zone. Our images provide a potential for discussing new structural features and will help better understanding of the dynamics of the NE Japan subduction zone.