【摘要】 2010年3月6日河北滦县发生ML4.5地震,其前震较为活跃且余震丰富。利用首都圈数字化地震台网监测到的2009年12月至2010年3月滦县ML≥2.5地震的宽频带数字地震波资料,计算得到地震视应力。结果表明:1 ML4.5地震视应力表现出震前存在高值异常,震时达到峰值,震后波动下降的变化特点,而且主震视应力远大于多数余震,由此推断该序列类型为主余型。2视应力的数值变化可以反映震源区应力状态,利用视应力的变化过程来探讨地震序列性质,结合传统序列判别方法,可以更准确地判别序列类型。3在震级ML≤3.3范围内震级与视应力大体为正相关。更多还原

【Abstract】 On March 6,2010,an earthquake of ML4.5took place in Luanxian of Hebei province with plenty of foreshocks and aftershocks.From December 2009 to March 2010,a series of greater than ML2.5earthquakes recorded by digital seismic network of the capital region,which were selected to calculate the apparent stress in this region.The result shows that,Firstly,high value anomaly of apparent stress appeared before the ML4.5and peak value appeared on the mainshock,then it decreased after the ML4.5earthquake.The apparent stress of the mainshock is much greater than most aftershocks,the sequence type is considered as major-after shocks.Secondly,the size of apparent stress perfectly reflect the state of the stress field in the hypocenter region,and we can discuss seismic sequence properties through the changing process of apparent stress,in combination with the traditional methods to identify sequence more accurately.Finally,in the case of magnitude less than or equal to ML3.3,correlation between magnitude and apparent stress is positive.更多还原