汪贞杰, 孙侃, 朱新运. 2019: 单台sPL震相测定珊溪水库地震震源深度. 地震学报, 41(6): 735-742. DOI: 10.11939/jass.20190110
引用本文: 汪贞杰, 孙侃, 朱新运. 2019: 单台sPL震相测定珊溪水库地震震源深度. 地震学报, 41(6): 735-742. DOI: 10.11939/jass.20190110
Wang Zhenjie, Sun Kan, Zhu Xinyun. 2019: Focal depth determination of Shanxi reservoir earthquakes from sPL phase with single station. Acta Seismologica Sinica, 41(6): 735-742. DOI: 10.11939/jass.20190110
Citation: Wang Zhenjie, Sun Kan, Zhu Xinyun. 2019: Focal depth determination of Shanxi reservoir earthquakes from sPL phase with single station. Acta Seismologica Sinica, 41(6): 735-742. DOI: 10.11939/jass.20190110

单台sPL震相测定珊溪水库地震震源深度

Focal depth determination of Shanxi reservoir earthquakes from sPL phase with single station

  • 摘要: 稀疏台网下的传统走时定位难以确定中小地震的震源深度,而地震波深度震相蕴含着震源深度信息,为确定地震震源深度提供了新的途径。近震深度震相sPL和直达Pg波到时差与震源深度呈线性关系,可用以约束地震震源深度。本文以珊溪水库2014年震群事件为例,利用单台sPL震相测定了地震震源深度。结果表明:震源深度的测定结果与基于水库台网高密度台站下Pg和Sg走时定位Hyposat方法和全波形拟合CAP方法测定的震源深度高度一致,为4—6 km,与区域活动断层探测结果相符。sPL震相的优势震中距为30—50 km,区域台网范围内sPL与Pg的到时差与震源深度的线性关系相对固定,因此利用单台sPL震相即可快速获取可靠的地震震源深度,适用于稀疏台网下的中小地震震源深度的确定,且误差可控制在1—2 km范围内。

     

    Abstract: It is difficult to determine focal depth via phase onset time fitting method for the regions where only sparse seismic stations are available. we demonstrate that focal depth can be well constrained with depth phase sPL which is sensitive to focal depth but insensitive to epicentral distance. With 2014 Shanxi reservoir earthquake swarm as a case study, this paper determined the focal depths of earthquakes by sPL phase with single station. The result show that the focal depths derived from sPL phase are well consistent with the results from CAP method and Hyposat method. The depths of the main shock and six ML>3.0 events are predominantly around 4−6 km, which is coincident with results of surveying and prospecting of active fault. Therefore sPL phase can be applied to small earthquakes for sparse network as it is well observed with small epicentral distances. Robust result of focal depth can be rapidly obtained by single broadband seismic station with bias of about 1−2 km.

     

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