Crustal thickness and Poisson’s ratio beneath Xiangfan seismic station revealed by teleseismic receiver functions
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摘要: 利用襄樊台2015—2018年记录的震中距30°—90°,震级5.5级以上(含5.5级)的高信噪比远震波形事件,通过时间域反褶积方法提取台站接收函数,并用H-k扫描叠加方法得到台站下方地壳厚度和波速比。结果表明,襄樊台下方地壳厚度为35 km,略高于大陆地壳平均厚度33 km,处于西部山区厚地壳与中东部薄地壳的过渡地带。泊松比偏低,存在因区域内地壳应力积累发生微小地震的可能性。Abstract: In this study, we used high signal-to-noise ratio teleseismic wave form data with an epicenter 30°—90° and the magnitude above 5.5 (including 5.5) of Xiangfan seismic station recorded during 2015—2018 to calculate the receiver functions using the time domain deconvolution method. The crustal thickness and vP/vS velocity ratio was obtained with the H-k stacking method. The results reveal that the crustal thickness beneath Xiangfan seismic station is 35 km, slightly higher than the average continental crustal thickness of 33 km. It is located in the transition zone between the thick crustal thickness of the western mountain area and the thin crustal thickness of the central and eastern parts. Poisson’s ratio is low and there is the possibility of minor earthquake due to the accumulation of regional crustal stress.
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Key words:
- receiver function /
- H-k stacking /
- crustal thickness /
- velocity ratio /
- Poisson’s ratio
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图 1 台站周边断层分布图
F1:襄樊—广济断裂;F2:钟祥断裂带;F3:南漳断裂带;F4:青峰断裂;F5:竹山断裂;F6:远安断裂带;F7:雾渡河断裂;F8:信阳—金寨断裂
Figure 1. Distribution of faults around Xiangfan seismic station
F1:Xiangfan-Guangji fault;F2:Zhongxiang fault zone;F3:Nanzhang fault zone;F4:Qingfeng fault; F5:Zhushan fault;F6:Yuanan fault zone;F7:Wuduhe fault;F8:Xinyang-Jinzhai fault
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[1] 钱银苹,沈旭章,李翠芹,等. 利用接收函数方法确定青藏高原东北缘近地表S波速度[J]. 地球物理学报,2018,61(10):3951-3963Qian Yinping,Shen Xuzhang,Li Cuiqin,et al. Constraining the sub-surface S-wave velocity of the northeastern margin of Tibetan Plateau with receiver functions[J]. Chinese Journal of Geophysics,2018,61(10):3951-3963 [2] 许英才,曾宪伟,许文俊,等. 基于台阵的青藏高原东北缘海原—六盘山断裂带及邻区地壳结构研究[J]. 中国地震,2018,34(3):484-497 doi: 10.3969/j.issn.1001-4683.2018.03.010Xu Yingcai,Zeng Xianwei,Xu Wenjun,et al. Research on crustal structure of the Haiyuan-Liupanshan fault zone and its adjacent in northeastern Qinghai-Tibetan plateau based on seismic array[J]. Earthquake Research in China,2018,34(3):484-497 doi: 10.3969/j.issn.1001-4683.2018.03.010 [3] 原世豪,陈永顺. 利用P波接收函数方法研究华北克拉通西部地壳和上地幔间断面[J]. 地球物理学进展,2015,30(6):2589-2595 doi: 10.6038/pg20150617Yuan Shihao,Chen Yongshun. Investigation on crustal and upper mantle discontinuities in western part of North China Craton using P wave receiver functions[J]. Progress in Geophysics,2015,30(6):2589-2595 doi: 10.6038/pg20150617 [4] 李天觉,陈棋福. 利用接收函数方法研究中国东北东南部地区不同构造体的地壳特征[J]. 地球物理学报,2019,62(8):2899-2917 doi: 10.6038/cjg2019M0379Li Tianjue,Chen Qifu. Crustal structure of different tectonic units in southeastern part of Northeast China using receiver functions[J]. Chinese Journal of Geophysics,2019,62(8):2899-2917 doi: 10.6038/cjg2019M0379 [5] 贺传松,王椿镛,吴庆举. 接收函数方法及其新的进展[J]. 地球物理学进展,2003,18(2):224-228 doi: 10.3969/j.issn.1004-2903.2003.02.008He Chuansong,Wang Chunyong,Wu Qingju. The receiver function method and its new progress[J]. Progress in Geophysics,2003,18(2):224-228 doi: 10.3969/j.issn.1004-2903.2003.02.008 [6] 徐强,赵俊猛. 接收函数方法的研究综述[J]. 地球物理学进展,2008,23(6):1709-1716Xu Qiang,Zhao Junmeng. A review of the receiver function method[J]. Progress in Geophysics,2008,23(6):1709-1716 [7] 张莹莹,高原,石玉涛,等. 张家口—渤海地震活动带及其邻区的地壳厚度与泊松比分布[J]. 地震学报,2015,37(4):541-553 doi: 10.11939/jass.2015.04.002Zhang Yingying,Gao Yuan,Shi Yutao,et al. Crustal thickness and Poisson’s ratio beneath Zhangjiakou-Bohai seismic active belt and its neighboring regions[J]. Acta Seismologica Sinica,2015,37(4):541-553 doi: 10.11939/jass.2015.04.002 [8] Zhu L P,Kanamori H. Moho depth variation in southern California from teleseismic receiver functions[J]. J. Geophys. Res.,2000,105(B2):2969-2980 doi: 10.1029/1999JB900322 [9] 何凯,杜瑞林,董彦君,等. 利用远震接收函数研究湖北地区地壳结构[J]. 大地测量与地球动力学,2018,38(6):646-649,660He Kai,Du Ruilin,Dong Yanjun,et al. Crustal structure and Poisson ratio beneath Hubei Province derived from teleseismic receiver functions[J]. Journal of Geodesy and Geodynamics,2018,38(6):646-649,660 [10] 何静,吴庆举,张瑞青,等. 利用接收函数研究兴蒙造山带阿巴嘎地区的地壳结构[J]. 地球物理学报,2018,61(9):3676-3688 doi: 10.6038/cjg2018M0013He Jing,Wu Qingju,Zhang Ruiqing,et al. Crustal structure beneath the Abaga area of Xing’an-Mongolia Orogenic Belt using teleseismic receiver functions[J]. Chinese Journal of Geophysics,2018,61(9):3676-3688 doi: 10.6038/cjg2018M0013 [11] 张广成,吴庆举,潘佳铁,等. 利用H-K叠加方法和CCP叠加方法研究中国东北地区地壳结构与泊松比[J]. 地球物理学报,2013,56(12):4084-4094 doi: 10.6038/cjg20131213Zhang Guangcheng,Wu Qingju,Pan Jiatie,et al. Study of crustal structure and Poisson ratio of NE China by H-K stack and CCP stack methods[J]. Chinese Journal of Geophysics,2013,56(12):4084-4094 doi: 10.6038/cjg20131213 -