大地震前区域能量场的时间因子异常特征
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摘要
本文采用自然正交函数展开方法,讨论了我国大陆发生的30次6.0级以上地震前的震中附近地区地震活动能量场的时间因子变化特征。结果表明,在大地震发生前,几个主要特征值所对应的典型场的时间因子均出现了明显的突升或突降变化,显示出与未来强地震有较好的对应关系。时间因子异常一般出现在震前1～3年,多数情况下小于2年,表现出异常的中短期特点;有些地震前异常出现时间小于3个月,显示出异常的短临性质。笔者认为,地震能量场时间因子可能是强地震前的一种有效的异常观测量和中短期异常指标。
Using the method of the natural perpendicular function development in this paper,the time facture variations and features of the energy field of the seismic activity in the regions around the epicenters before 30 earthquakes of M≥6.0 occureed in the main continent have been discussed.The results have indicated that before these large earthquakes,the time factors of the typical fields corresponding to several key eigenvalues all appear very evident abrupt rising or abrupt depressing variations,showing better corresponding relation with the future strong earthquakes.The time factor anomalies appear 1~3 years before the main shocks,less than 2 years in most cases,indicating the medium-short features of the anomalies.And the time factor anomalies appear less than 3 months before some earthquakes,indicating the impending features of the anomalies.We think that time factures of the seismic energy field are probably a kind of effective anomaly observation measure and the medium-short anomaly index before strong earthquakes.
Using the method of the natural perpendicular function development in this paper,the time facture variations and features of the energy field of the seismic activity in the regions around the epicenters before 30 earthquakes of M≥6.0 occureed in the main continent have been discussed.The results have indicated that before these large earthquakes,the time factors of the typical fields corresponding to several key eigenvalues all appear very evident abrupt rising or abrupt depressing variations,showing better corresponding relation with the future strong earthquakes.The time factor anomalies appear 1~3 years before the main shocks,less than 2 years in most cases,indicating the medium-short features of the anomalies.And the time factor anomalies appear less than 3 months before some earthquakes,indicating the impending features of the anomalies.We think that time factures of the seismic energy field are probably a kind of effective anomaly observation measure and the medium-short anomaly index before strong earthquakes.
引文
[1]杨明芝,马禾青.汶川8.0级地震区域地震能量场分析[J].地球物理学进展,2012,27(3):872-877.
[2]杨明芝,赵卫明.宁夏及邻近地区地震活动能量场的统计分析[J].地震学报,2004,26(5):516-522.
[3]罗国富,杨明芝.云南地区地震活动能量场的时空分布特征[J].中国地震,2005,21(3):332-340.
[4]杨明芝,马禾青.汶川8.0级地震前龙门山断裂带能量场变化[J].中国地震,2011,27(3):260-267.
[2]杨明芝,赵卫明.宁夏及邻近地区地震活动能量场的统计分析[J].地震学报,2004,26(5):516-522.
[3]罗国富,杨明芝.云南地区地震活动能量场的时空分布特征[J].中国地震,2005,21(3):332-340.
[4]杨明芝,马禾青.汶川8.0级地震前龙门山断裂带能量场变化[J].中国地震,2011,27(3):260-267.
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