摘要
对上地幔波速结构的研究有助于认识上地幔物质组成和温度分布,同时还可以为地球动力学的研究提供约束条件。笔者根据中国数字地震台网记录到的位于东亚地区的两个地震波路径近似相互垂直的地震事件,通过三重震相波形模拟的方法,对探测区域下方的上地幔速度结构进行了研究。结果表明,两个不同方向的地震事件得到的波速模型均在250 km以上存在低速带,波速降幅两者有差异;过渡带下半部分均存在高速带,表明该区域过渡带受到东亚俯冲板块的影响。该区域过渡带厚度无明显变化是两个不连续面附近温度和成分分布不同造成的,和该区域过渡带受俯冲带影响的结论不矛盾。
Understanding upper mantle velocity structures can help us understand the mantle temperature and composition distribution and provide clues for geodynamics study.We study the upper mantle velocity structure beneath northeast Asia,based on S triplication data of two earthquake events in East Asia,recorded by China Digital Seismogragh network.The modeling results of these two events show that both models have a low-velocity zone above 250 km,and a high-velocity zone at the lower part of the mantle transition zone,which suggests the influence of the Pacific subduction slab in this area.The thickness of the mantle transition zone of both models is the same as PREM because the influences of the slab near the two discontinuities are different.
作者
赵一帆
王毅
ZHAO Yifan;WANG Yi(School of Earth and Space Sciences,University of Science and Technology of China,Hefei 230026,China)
出处
《物探化探计算技术》
CAS
2024年第2期137-145,共9页
Computing Techniques For Geophysical and Geochemical Exploration
