川西北倒三角形断块东部区域强震带形成机制与地震活动特征
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摘要
川西北倒三角形断块东部区域地处青藏高原东部边缘地带,地跨川西北高原及其与四川盆地过渡带的高山峡谷区,属我国著名的南北向地震带的中段,因其特定的大地构造环境和强烈的现代地壳构造运动,导致其在强大的近东西向构造应力场的驱动和平卧“A”字型控震构造体系的控制下,沿两侧边界断裂向东强力楔入,于“构造急剧收口带”之西侧形成了一个近SN向地跨三大构造单元的强震带,强震沿该带有规律的往返迁移和重复发生,且地震活动强弱具有较明显的分形特征。
The east part of inverted-triangle-shaped fault block in the northwest of Siehuan is situated in the northwest plateau of Siehuan and the valley of transitional area between that and Sichuan basin, of the northeast edge of Qingzang plateau. Due to its specific tectonic environment and intensive modern crust movement, earthquakes occur frequently.
Based on study of geological and seismic data, according to field investigation, fractal analysis,we discover the distribution characteristics and formation mechanism of strong seismic belts in the present in the east part of the triangle fault block and two fault belts in northern and southeastern boundary under recent E-W compress regional tectonic stress-strain field and A-type tectonic system controlling earthquakes; we also discover the seismic activity law of this region. Generally speaking, seismic activity belts located near 104°E. in the form of dense strip. Besides, the frequency and maximum earthquake magnitude inside the fault block are higher than those in boundary faults and the seismic intensity in the north is far larger than that in the south. As far as the space is concerned, intensive earthquakes in 104°E can transfer from boundary faults to those inside and vice versa, when it comes to he time, the active period and dormant period alternate and the earthquake whose magnitude is larger than 7.0 tends to accelerated.
The east part of inverted-triangle-shaped fault block in the northwest of Siehuan is situated in the northwest plateau of Siehuan and the valley of transitional area between that and Sichuan basin, of the northeast edge of Qingzang plateau. Due to its specific tectonic environment and intensive modern crust movement, earthquakes occur frequently.
Based on study of geological and seismic data, according to field investigation, fractal analysis,we discover the distribution characteristics and formation mechanism of strong seismic belts in the present in the east part of the triangle fault block and two fault belts in northern and southeastern boundary under recent E-W compress regional tectonic stress-strain field and A-type tectonic system controlling earthquakes; we also discover the seismic activity law of this region. Generally speaking, seismic activity belts located near 104°E. in the form of dense strip. Besides, the frequency and maximum earthquake magnitude inside the fault block are higher than those in boundary faults and the seismic intensity in the north is far larger than that in the south. As far as the space is concerned, intensive earthquakes in 104°E can transfer from boundary faults to those inside and vice versa, when it comes to he time, the active period and dormant period alternate and the earthquake whose magnitude is larger than 7.0 tends to accelerated.
引文
[1] 蒋良文.岷江上游活动断裂及主要地质灾害研究[D].成都:成都理工学院,1999．
[2] 唐荣昌,韩渭宾主编.四川活动断裂与地震[M].北京:地震出版社,1993．
[3] 林茂炳,苟宗海,等.四川龙门山造山带造山模式研究[M].成都:成都科技大学出版社,1996．
[4] 林茂炳,苟宗海,等.龙门山中段地质[M].成都:成都科技大学出版社,1996．
[5] 陈社发,邓起东,赵小麟,等.龙门山中段推覆构造带及相关构造的演化历史和变形机制(一、二)[J].地震地质,1994,16(4) :404-421．
[6] 吴刚.龙门山推覆构造与地震活动[J].地震研究,1992,15(3) :291-297．
[7] 邓起东,陈社发,等.龙门山及其邻区的构造和地震活动及动力学[J].地震地质,1994,16(4) :389-403．
[8] Okubo P G, et al. Fractal Geometry in the San Andress Fault system[J]. Journal of Ceophysical Research, 1987,92 (11) :345-355．
[9] 琼斯,等.1976年松潘地震的震源机制及余震定位[A].见:松潘地震预报学术讨论会文集[C].北京:地震出版社.1989．
[10] 谢毓寿,程德利,丁学仁编.1900-1980年中国M_e≥4． 7级地震的均一震级目录[M].北京:地震出版社.1989．
[11] 吕弋培,廖华.四川及邻区地壳垂直形变特征与地震的关系[J].四川地震,1996,(4) :109-116．
[12] 李建中.川西地区的区域形变与中长期地震趋势[J].四川地震,1995,(4) :55-59．
[13] 国家地震局编.中国地震简目[M].北京:地震出版社,1977．
[14] 兰州地震研究所.陕甘宁青四省区强地震目录[M].西安:陕西科技出版社,1985．
[15] 四川省地震局编著.1933年叠溪地震[M].成都:四川科学技术出版社,1985．
[16] 陈培普.地震目录[J].地震学报,1989-1998． 11-20．
[17] 中科院地球物理所编.中国强地震简目[M].北京:地图出版社,1976．
[18] 江道崇.龙门山地震带地震活动特征的研究[J].四川地震,1995,(4) :10-18．
[19] 四川省地震局.1976年松潘地震[M].北京:地震出版社,1979．
[20] 周寅康,张捷.分形论与自然灾害研究-地震、洪涝灾害中的分形研究[J].自然灾害学报,1995,4(4) :9-15．
[21] 陈春仔,兰朝利.分形理论在地质科学中的应用[J].地学探索,1997,(13) .
[22] 洪时中,洪时明.地学领域中的分维研究:水系、地震及其它[J].大自然探索,1988,7(24) :33-40．
[2] 唐荣昌,韩渭宾主编.四川活动断裂与地震[M].北京:地震出版社,1993．
[3] 林茂炳,苟宗海,等.四川龙门山造山带造山模式研究[M].成都:成都科技大学出版社,1996．
[4] 林茂炳,苟宗海,等.龙门山中段地质[M].成都:成都科技大学出版社,1996．
[5] 陈社发,邓起东,赵小麟,等.龙门山中段推覆构造带及相关构造的演化历史和变形机制(一、二)[J].地震地质,1994,16(4) :404-421．
[6] 吴刚.龙门山推覆构造与地震活动[J].地震研究,1992,15(3) :291-297．
[7] 邓起东,陈社发,等.龙门山及其邻区的构造和地震活动及动力学[J].地震地质,1994,16(4) :389-403．
[8] Okubo P G, et al. Fractal Geometry in the San Andress Fault system[J]. Journal of Ceophysical Research, 1987,92 (11) :345-355．
[9] 琼斯,等.1976年松潘地震的震源机制及余震定位[A].见:松潘地震预报学术讨论会文集[C].北京:地震出版社.1989．
[10] 谢毓寿,程德利,丁学仁编.1900-1980年中国M_e≥4． 7级地震的均一震级目录[M].北京:地震出版社.1989．
[11] 吕弋培,廖华.四川及邻区地壳垂直形变特征与地震的关系[J].四川地震,1996,(4) :109-116．
[12] 李建中.川西地区的区域形变与中长期地震趋势[J].四川地震,1995,(4) :55-59．
[13] 国家地震局编.中国地震简目[M].北京:地震出版社,1977．
[14] 兰州地震研究所.陕甘宁青四省区强地震目录[M].西安:陕西科技出版社,1985．
[15] 四川省地震局编著.1933年叠溪地震[M].成都:四川科学技术出版社,1985．
[16] 陈培普.地震目录[J].地震学报,1989-1998． 11-20．
[17] 中科院地球物理所编.中国强地震简目[M].北京:地图出版社,1976．
[18] 江道崇.龙门山地震带地震活动特征的研究[J].四川地震,1995,(4) :10-18．
[19] 四川省地震局.1976年松潘地震[M].北京:地震出版社,1979．
[20] 周寅康,张捷.分形论与自然灾害研究-地震、洪涝灾害中的分形研究[J].自然灾害学报,1995,4(4) :9-15．
[21] 陈春仔,兰朝利.分形理论在地质科学中的应用[J].地学探索,1997,(13) .
[22] 洪时中,洪时明.地学领域中的分维研究:水系、地震及其它[J].大自然探索,1988,7(24) :33-40．
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