地震工程学报Issue(2)：314-319,6.DOI:10.3969/j.issn.1000-0844.2014.02.0314
岷县漳县6．6级地震前地震活动能量场分析
Analysis of Energy Field of Seismic Activity before the Minxian-Zhangxian MS6.6 Earthquake
摘要
Abstract
The Minxian-Zhangxian MS 6.6 earthquake that occurred on Jul.22,2013 is of great interest to the earthquake research community.In this paper,we describe the data we obtained for energy released by earthquakes and use the data to represent the basic elements of the seismic en-ergy field.Then,we discuss the spatiotemporal features of the regional seismic activity by the ran-dom function theory and the method of natural perpendicular function before 2013.The time weight factors of the typical energy field indicate that the energy field was increasing in this re-gion.The factors corresponded to the four key eigenvalues of the energy field before the Minxian-Zhangxian MS 6.6 earthquake.The spatial image of the key typical fields showed a danger zone having an abnormally high value relative to local energy,which may be the medium-short-time ab-normal.After analyzing the mean spatial image of the energy field in recent years,indications are that the Minxian-Zhangxian MS 6.6 earthquake occurred in a high release zone of energy field, which may be the medium-short-space abnormal.Finally,after analyzing the mean energy field of the image of different time periods and different study areas,we found that high values of the long-time energy field existed before the earthquake.Several conclusions can be drawn including that the zone of high values may be the danger zone,mean value of short-time energy field is sig-nificantly abnormal,and,furthermore,there is along-time high value danger region of seismic en-ergy field in the south of the Ningxia area.Although the mean abnormal of short-time seismic en-ergy field is non-notable,our analysis suggests that there may be a strong earthquake in the region the next few years.Additionally,we analyzed the seismic energy field in the epicenter region of the Minxian-Zhangxian MS 6.6 earthquake.Our analysis indicates that there were different dis-tinct changes of four time factors of typical seismic energy fields from Sep.to Nov.2011,Aug.to Nov.2012,and Apr.to July 2013.In other words,a medium-short abnormal characteristic of the seismic energy field existed two years before the earthquake on July 22,2013.Secondly,by analy-zing the spatial contours of the two main seismic energy fields of the July 22,2013 earthquake our research indicates that a danger area of high value abnormal of seismic energy field existed near the Minxian and Zhangxian in the preceding five years.The danger area may have coincided with the spatial anomaly of the July 22,2013 earthquake.Thirdly,by analyzing distribution character-istics of spatial contours of the seismic energy field over different time periods,we concluded that there were spatial medium-short high value abnormal regions of earthquake energy at different times and for different epicenter areas before the July 22,2013 earthquake.Furthermore,strong earthquake danger may exist near several faults including the Lixian-Luojiapu fault and Diebu-Bailongjiang fault in the region of south-east of Gansu province,Xiangshan-Tianjingshan fault, Haiyuan fault,and Liupan mountain fault in the south of Ningxia.Fourthly,we can analyze time-space information for abnormal earthquake activity using the method of natural orthogonal func-tion.This type of analysis may help to forecast a strong earthquake or medium-strong earthquake, in a strong earthquake danger area.关键词
岷县漳县 6.6 级地震/地震活动/能量场/随机函数/时间因子/高值异常Key words
Minxian-Zhangxian MS 6.6 earthquake/seismic activity/energy field/random func-tion/time factor/high value anomaly分类
天文与地球科学引用本文复制引用
罗国富,曾宪伟,马禾青,杨明芝..岷县漳县6．6级地震前地震活动能量场分析[J].地震工程学报,2014,(2):314-319,6.基金项目
地震科技星火计划项目 （）
