2008年攀枝花6.1级地震序列精定位
详细信息 本馆镜像全文    |  推荐本文 | | 获取馆网全文
摘要
利用四川和云南区域数字地震台网震相到时资料,并结合Hypo2000+Hypo DD对2008年8月30日攀枝花MS6.1地震序列进行了定位。定位结果表明,地震序列的震中在空间上呈近SN向展布,余震密集区长度约为30km,主震震源深度约为14km。序列深度的分布范围主要为0~4、5~20km,而4~5km范围显示为明显的少震层。沿序列长轴的深度剖面显示,余震区中段存在1个不规则的少震的"空区",为1955年634级地震的破裂区,该地震发生在空区的南端。分析认为,2008年8月30日攀枝花MS6.1地震是因汶川8.0级地震后的应力调整造成未破裂的小凹凸体发生破裂所致。余震密集分布区沿垂直于破裂长轴的两个剖面则显示了在其北端地震震源分布更深,且断层面向NW倾斜,与已知的红格断裂的倾向一致。
The Panzhihua MS6. 1 earthquake sequence on August 30,2008,which was relocated by the Hypo2000 + Hypo DD method using the phase data from the Sichuan and Yunnan Regional Digital Seismic Network,showed that the epicenters distribute in NS,the length of the dense aftershocks' region is about 30 km,and the main shock is about 14 km in depth. The sequence is separated in layers of 0 ~ 4km and 5 ~ 20 km in depth,then the 4 ~ 5km embodies an apparent earthquake absence layer. The cross-section along the fracture's long axis shows there is a irregular seismic gap in the middle segment of the aftershock region,that is the crack region of the M63/4 earthquake in 1955,and this earthquake occurred in the south of the gap. We believed that the Panzhihua MS6. 1 earthquake sequence on August 30,2008 was a result from the residual asperity cracking forced by the stress adjustment of the Wenchuan MS8. 0 earthquake. The other two profiles perpendicular to the long axis show the north segment is more deeper and dips to NW,and this is correspondent to the known Hongge fault.
引文
陈九辉、刘启元、李顺成等,2009,汶川MS8.0地震余震序列重新定位及其地震构造研究,地球物理学报,52(2),390~397。
    龙锋、闻学泽、徐锡伟,2006,华北地区地震活断层的震级-破裂长度、破裂面积的经验关系,地震地质,28(4),511~535。
    龙锋、张永久、闻学泽等,2010,2008年8月30日攀枝花-会理6.1级地震序列ML≥4.0事件的震源机制解,地球物理学报,53(12),2852~2860。
    梅世蓉,1960,中国的地震活动性,地球物理学报,9(1),1~19。
    闻学泽、范军、易桂喜等,2008,川西安宁河断裂上的地震空区,中国科学D辑,38(7),797~807。
    熊绍柏、郑晔,1993,丽江-攀枝花-者海地带二维地壳结构及其构造意义,地球物理学报,36(4),434~444。
    胥颐、黄润秋、李志伟等,2009,龙门山构造带及汶川震源区的S波速度结构,地球物理学报,52(2),329~338。
    杨智娴、陈运泰,2004,用双差地震定位法再次精确测定1998年张北-尚义地震序列的震源参数,地震学报,26(2),115~120。
    易桂喜、姚华建、朱介寿,2008,中国大陆及邻区Rayleigh面波相速度分布特征,地球物理学报,51(2),402~411。
    赵卫明、金延龙,1992,1988年灵武地震序列的精确定位和发震构造,地震学报,14(4),416~422。
    赵珠、张润生,1987,四川地区地壳上地幔速度结构的初步研究,地震学报,9(2),154~166。
    中国地震局震害防御司,1999,中国近代地震目录,1~637,北京:中国科学技术出版社。
    朱艾斓、徐锡伟、周永胜等,2005,川西地区小震重新定位及其活动构造意义,地球物理学报,48(3),629~636。
    Aki K,1984,Asperities,barriers,characteristic earthquakes,and strong motion prediction,J Geophys Res,89(B7),5867~5872.
    Bayrak Y,Oztürk S,2004,Serkan spatial and temporal variations of the aftershock sequences of the 1999 Izmit and Duzce earthquakes,Earth Planets Space,56(10),933~944.
    Geiger L,1912,Probability method for the determination of earthquake epicenters from arrival time only,Bull St Louis Univ,8(1),60~71.
    Klein F W,2002,User’s guide to HYPOINVERSE-2000,a fortran program to solve for earthquake locations and magnitudes,CA:USGS,open file report 02-171 revised.
    Mogi K,1979,Two kinds of seismic gaps,Pure Appl Geophys,117(6),1172~1186.
    Waldhauser F,Ellsworth W L,2000,A double-difference earthquake location algorithm:method and application to the northern Hayward fault,California,Bull Seism Soc Am,90(6),1353~1368.
    Wiemer S,Katsumata K,1999,Spatial variability of seismicity parameters in aftershock zones,J Geophys Res,104(B6),13135~13151.
    Yielding G,Ouyed M,King G C P,et al,1989,Active tectonics of the Algerian Atlas Mountains-evidence from aftershocks of the 1980 Elasnam earthquake,Geophys J Int,99(3),761~781.
    1四川省地震局,2008,2008年8月30日四川攀枝花市仁和区、凉山彝族自治州会理县交界6.1级地震灾害直接损失评估报告。

版权所有:© 2023 中国地质图书馆 中国地质调查局地学文献中心