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地震 ›› 2016, Vol. 36 ›› Issue (3): 99-108.

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云南宾川地区的地壳厚度和泊松比分布特征研究

邓嘉美, 陈佳, 高琼, 张华英, 王军, 叶泵, 李孝宾   

  1. 中国地震局滇西地震预报实验场办公室, 云南 大理 671000
  • 收稿日期:2015-11-30 发布日期:2020-07-03
  • 作者简介:邓嘉美(1978-), 女, 云南弥渡人, 工程师, 主要从事地震监测预报和数字地震学研究。
  • 基金资助:
    云南省地震局陈颙院士工作站和云南省地震局科技专项基金(KJZX02)联合资助

Crustal Thickness and Poisson’s Ratios beneath the Binchuan Region of Yunnan Province

DENG Jia-mei, CHEN Jia, GAO Qiong, ZHANG Hua-ying, WANG Jun, YE Beng, LI Xiao-bin   

  1. Office of the Western Yunnan Earthquake Prediction Study Area, CEA, Yunnan Dali 671000, China
  • Received:2015-11-30 Published:2020-07-03

摘要: 利用宾川主动源项目16个地震台站2011年9月~2014年1月期间记录的5.8级以上远震波形资料, 提取各台站下方的P波接收函数, 并据此计算、 分析宾川地区地壳厚度变化情况和泊松比分布特征。 高空间分辨率的结果显示: 宾川地区平均地壳厚为45.3 km, 地壳厚度呈“北深南浅”、 “西浅东深”的特征。 地壳厚度最深的是小银甸, 47.9 km, 最浅的是排营台, 42.1 km, 两者相差5.8 km。 程海断裂附近Moho面较深, 红河断裂附近Moho面较浅; 程海断裂附近地壳厚度变化较明显, 红河断裂附近变化较缓。 从泊松比的分布情况来看, 研究区内泊松比分布是不均匀的, 自南向北存在较大差异, 呈“北低南高”的特征。 红河断裂附近, 泊松比属于中高(0.26≤σ≤0.29), 程海断裂附近, 泊松比较低(σ≤0.26)。 泊松比分布特征和地壳厚度相反, 表明宾川地区的增厚方式主要由上地壳增厚所致。

关键词: 地壳厚度, 泊松比, 接收函数, 宾川地区

Abstract: We use teleseismic records of M≥6.0 earthquakes between September 2, 2011 to January 16, 2014 from 16 seismic stations of the Binchuan Active Source Study to get the P-wave receiver function information from every station, calculate and analyze changes of crust thickness and distribution of Poisson's ratios in the Binchuan region. Finally, we get a high spatial resolution result of the crust thickness in Binchuan region with an average value of 45.3 km, which shows v a characteristic of ‘deeper in the north and east part, shallower in th south and west part’. The deepest region locates in the Xiaoyindian Station with thickness of 47.9 km; the shallowest region in Paiying Station with thickness of 42.1 km. We find deeper Moho boundary nearby the Chenhai Fault and shallower nearby Honghe Fault; the isoline distribution of thickness changes greatly nearby Chenhai Fault and slowly nearby Honghe Fault. From the distribution of Poisson′s ratios, we find it’s unevenly in the study area with great difference from the north part to the south part, which shows a characteristic of ‘lower in the north , higher in th south’. The Poisson’s ratio nearby Honghe Fault is medium to high (0.26≤σ≤0.29); lower nearby Honghe Fault (σ≤0.26). We conclude that the possible reason of different characteristic between Poisson′s ratio and crust thickness is thicker in the upper crust of the Binchuan region.

Key words: Crust thickness, Poisson&apos, s ratio, Receiver function, The Binchuan region

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