黎明晓,刘杰,薛艳,姜祥华,苑争一,闫伟,于磊. 2024. 鲁东—黄海地块西部中强地震活动特征及周边地震对该地区的影响. 地震学报,46(3):1−17.
引用本文: 黎明晓,刘杰,薛艳,姜祥华,苑争一,闫伟,于磊. 2024. 鲁东—黄海地块西部中强地震活动特征及周边地震对该地区的影响. 地震学报,46(3):1−17.
Li M X,Liu J,Xue Y,Jiang X H,Yuan Z Y,Yan W,Yu L. 2024. Characteristics of moderate-strong seismicity in the western Ludong-Huanghai block and the influence from surrounding earthquakes. Acta Seismologica Sinica46(3):1−17.
Citation: Li M X,Liu J,Xue Y,Jiang X H,Yuan Z Y,Yan W,Yu L. 2024. Characteristics of moderate-strong seismicity in the western Ludong-Huanghai block and the influence from surrounding earthquakes. Acta Seismologica Sinica46(3):1−17.

鲁东—黄海地块西部中强地震活动特征及周边地震对该地区的影响

Characteristics of moderate-strong seismicity in the western Ludong-Huanghai block and the influence from surrounding earthquakes

  • 摘要: 鲁东—黄海地块西部为华北地块东侧的次级地块,其地震活动具有显著的周期特征,地块内部的中强地震活动特征和周边大震对该地区的影响,对研究该地区地震活动状态有重要意义。采用小波分析方法定量计算了鲁东—黄海地块西部历史地震的活动周期,并结合中强地震活动的定性分析、时空演化、能量释放及周边大震等资料,探讨了该地区的地震活动特征。结果显示:① 鲁东—黄海地块西部M5.0以上地震活动存在着60.6—78.6 a的长周期,该周期反映了地震活跃—平静的韵律特征,据此M≥5.0地震可划分为第 Ⅰ (1844—1879年)、第 Ⅱ(1905—1949年)和第Ⅲ(1974年至今)活跃时段。1997年以来,该地区处于活跃时段末期的弱释放阶段;② 在三个活跃时段,地震活动的主体地区不同,第Ⅰ和第Ⅱ活跃时段以海域地震活动为主,并且海域强、陆域弱。第Ⅲ活跃时段,陆域、海域均有M≥6.0地震活动;③ 1815年以来,鲁东—黄海地块西部M≥5.0地震与华北M≥6.0地震活动大致同步,当鲁东—黄海地块西部中强地震恰好处于较强活跃时,华北M6.0地震显著平静后先以鲁东—黄海地块西部M6.0地震开始,然后向华北中西部地区活动;④ 太平洋板块西侧的俯冲带上?M≥5.0中深源地震活跃,当其同时发生M≥7.0地震时,有利于鲁东—黄海地块西部发生M≥6.0地震,可能反映深部的俯冲构造动力作用加强。

     

    Abstract: The seismicity in the western Ludong-Huanghai block, a sub block in the eastern side of the North China block, has a significant periodic characteristic. Therefore, it is of great significance to study the seismicity in this area, the characteristics of its internal moderate strong seismicity and the influence from surrounding large earthquakes. In this paper, the wavelet analysis method is used to quantitatively calculate the activity period of historical earthquakes in the block. At the same time, in combination with the data on qualitative analysis of moderate-strong seismicity, temporal and spatial evolution, energy release and the influence from surrounding large earthquakes, the state and characteristics of seismicity in the block are discussed. Results show that (1) There is a long periodicity of 60.6−78.6 years for earthquakes with M≥5.0 in the western Ludong-Huanghai block, which reflects the rhythmic characteristics of seismic active-quiescence. Based on which, earthquakes with M≥5.0 can be divided into active periods Ⅰ (1844−1879), Ⅱ (1905−1949), and Ⅲ (1974 to present). Since 1997, the seismicity in the western Ludong-Huanghai block has been in the weak release period at the end of the active period; (2) In the three active periods, the main seismic areas are different. In the first and second active periods, the seismicity in the sea is dominant, and the earthquakes in the sea are stronger than those in the land, while in the third active period, it is very different. In which, earthquakes with M≥6.0 are presented in both land and sea; (3) Since 1815, earthquakes with M≥5.0 in the western Ludong-Huanghai block and those with M≥6.0 in the Northern China block have roughly exhibited synchronous activity characteristics. In other words, when earthquakes with M≥5.0 in the western Ludong-Huanghai block happen in a strong active period, the significant calm of earthquakes with M≥6.0 in the Northern China is generally first broken by earthquakes in the western Ludong-Huanghai block. Then, the seismic activity moves towards the central and western areas in the Northern China block; (4) When intermediate and deep-focus earthquakes with M≥5.0 in the subduction zone are active and those with M≥7.0 happen at the same time on the western side of the Pacific plate, it is conducive to the occurrence of earthquakes with M≥6.0 in the western Ludong-Huanghai block, which may reflect the strengthening of subduction tectonic dynamic action.

     

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