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本文对2014年8月3日云南鲁甸6.5级地震早期余震序列中因波形叠加而遗漏的地震进行了检测,并基于修正的大森公式对序列时间域衰减特征进行了分析.首先利用巧家台连续地震记录波形的高频包络差检测主震发震至当日24点约7.5小时内目录遗漏的地震事件.检测到目录遗漏的ML2.0以上地震159个,最大震级为ML4.2,其中ML4.0以上遗漏地震1个,ML3.0以上遗漏地震3个.主震后1000秒内检测到遗漏地震37个,约为目录给出余震数量的1.76倍.使用补充遗漏地震的目录,基于修正的大森公式拟合主震后10天余震频度随时间的变化.增补遗漏地震后拟合p值由0.85上升至0.99,c值和K值无明显变化,表明鲁甸地震早期余震序列衰减速率高于仅依靠目录得到的结果.遗漏地震检测对于估计早期余震序列衰减速率估计影响较大,早期余震的缺失易造成序列衰减速度的低估.
In this paper, the earthquakes missed by waveform superposition in the early aftershocks sequence of the Ms6.6 earthquake in Yunnan Province on August 3, 2014 were detected, and the attenuation characteristics of the sequence time domain were analyzed based on the modified Omori formula.First, High-frequency Envelope Difference of Continuous Seismogram Waveforms The Earthquake Occurred in Less Than 7.5 Hours After Seismogenic Seismic Seismic Episode about 24 Hours on the Day of the Sept. A total of 159 earthquakes ML2.0 above the omission list were detected, with a maximum magnitude of ML4.2 ML4.0 missed more than one earthquake, ML3.0 missing earthquakes 3. Missing earthquakes were detected within 1000 seconds after the main shock 37, about 1.76 times the catalog gives the number of aftershocks.Use to supplement the list of missing earthquakes, based on The modified Omori formula fits the 10-day aftershock frequency variation with time after the main shock, and the fitted p-value increases from 0.85 to 0.99 with no additional changes in c and K values after addition of missed earthquakes, indicating that the early aftershock sequence of the Ludian earthquake attenuated The rate is higher than that obtained by relying only on the catalog.The omission of seismic detection has a great influence on the estimation of the decay rate of early aftershocks, and the loss of early aftershocks can easily lead to the underestimation of the decay rate.