Detecting velocity structure around 660-kmdiscontinuity beneath Northeastern China
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摘要: 我国东北地区位于西北太平洋和达-贝尼奥夫俯冲带前缘，其深部速度结构对理解板块俯冲行为以及地幔物质的交换有重要意义．利用区域三重震相模拟方法，对中国地震观测台网记录到的两个深源地震P波和SH波波形数据，进行了相对到时和波形的拟合，获得了我国东北地区660 km间断面附近波速结构．结果表明，研究区域下方的间断面没有发生明显下沉，间断面之上存在一个厚约130 km的高速层，这可能对应了俯冲并滞留在间断面之上的西北太平洋板块；地幔过渡带整体呈现出S波低速异常和较高的vP/vS值，可能暗示了地幔转换带内含有较高的水．
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关键词:
- 三重震相 660 /
- km间断面 俯冲板块 S波低速异常 东北地区
Abstract: Located at the front edge of the Wadati-Benioff zone of subducted northwestern Pacific plate, the velocity structure in the mantle transition zone beneath Northeastern China plays an important role in constraining the behavior of subducted slabs and material or energy exchange in mantle. By modeling P and SH triplicate waveforms from two deep events, recorded by a dense regional network stations, we show that a layer of fast anomaly, about 130 km thick, lies above the 660-km discontinuity with slight depression, which may be associated with the westward extension of the stagnant Pacific slab. The mantle transition zone, as a whole, is featured by low shear wave velocity and high vP/vS ratio, which may indicate the existence of a water-bearing mantle transition zone. -
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期刊类型引用(4)
1. 赵一帆，王毅. 基于三重震相波形模拟的东北亚地区上地幔S波速度结构研究. 物探化探计算技术. 2024(02): 137-145 . 
百度学术
2. 苏慧，魏荣强，周元泽，崔清辉，李国辉. 东北亚边缘地区地幔过渡带内滞留太平洋板片上界面的三重震相研究. 地球物理学报. 2023(06): 2431-2444 . 百度学术
3. 崔辉辉，周元泽，石耀霖，王晓冉，李国辉. 华北克拉通东部滞留板块下方低速异常的地震三重震相探测. 地球物理学报. 2016(04): 1309-1320 . 百度学术
4. 李国辉，眭怡，周元泽. 基于P波三重震相的下扬子克拉通地幔转换带顶部低速层初探. 地球物理学报. 2014(07): 2362-2371 . 百度学术
其他类型引用(11)
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