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1.
构造地貌能够记录构造运动的长期积累,并能通过相关参数定量表达。水系是对构造作用反映最敏感的地貌之一,长期以来许多研究者利用水系来反映和研究构造。但是过去的研究大都集中在垂直运动的构造作用区域上,尤其是正断层区域上,而对走滑作用区域的研究非常少。文中以南汀河断裂带为研究区域,利用高精度DEM数据提取水系。通过研究断层附近水系流域的偏转来研究南汀河断裂带的运动模式。通过分析流水地貌对断层活动的响应特征,对断裂带的空间展布和活动性进行了分析,为探讨活动断层与地貌响应之间的关系提供良好范例。  相似文献   

2.
伍先国  蔡长星 《地震研究》1992,15(4):401-410
作者通过对区域地质调查资料的分析研究和实地考察,对金沙江断裂带的展布范围进行了划分,认为金沙江断裂带是川西规模巨大的断裂带,从地震活动、断裂地貌特征、水系扭曲、第四纪地层形变和温泉沿断裂分布等表明它是一个活动断裂带。通过对历史地震实地访问调查,获得了1923年巴塘6.5级地震的震害情况,并发现了这次地震在地表所产生的地裂缝,从而确定了这次地震的宏观震中位置,探讨了地震与断裂的关系。无疑对金沙江断裂带活动性的认识、地震预报和地震烈度区划工作具有现实意义。  相似文献   

3.
新疆伊犁喀什河断裂带及其活动性研究   总被引:5,自引:4,他引:5  
尹光华  蒋靖祥  张勇 《内陆地震》2003,17(2):109-116
通过对1812年新疆伊犁尼勒克地震的考察研究,认为该地震以地震断层为主体的地表地震形变带展布方向与发震断裂喀什河断裂带的走向一致。喀什河断裂带可分为3段,全长315km,它是由多条断层组成的活动断裂带,总体以逆冲活动为主,东段具有右旋扭错性质。喀什河断裂带具有长期发育的历史,它控制了中生代地层的分布,在新生代仍有多次活动并以垂直运动为主,晚第四纪以来的垂直活动速率为O.9—6mm/a。  相似文献   

4.
张北-尚义地震与大同-阳高地震地震活动对比研究   总被引:4,自引:0,他引:4       下载免费PDF全文
邓志辉  楚全芝 《地震地质》1998,20(2):77-178
张北-尚义地震与大同-阳高地震虽然相距不远,但在地震活动性上有较大的差异。大同-阳高地震前,区域地震活动、断裂带附近微震活动、震源邻区地震活动趋势、地震活动空区展布和余震分布都与北东或北西向这组共轭构造一致;张北-尚义地震前,区域地震活动、断裂带附近微震活动、震源邻区地震活动趋势、地震活动空区展布和余震分布则与近南北或近东西向这组共轭构造平行。产生这种方向差异的原因可能是构造条件的差异以及附加应力场的不同  相似文献   

5.
太行山山前断裂带活动特征及地震危险性讨论   总被引:7,自引:0,他引:7  
太行山山前断裂带呈隐伏断裂展布于太行山脉与华北平原之间。该断裂带浅部由一系列北东至北北东方向的正断层斜列组成,控制了华北平原西部一系列隆起、断陷的形成;深部深切莫霍界面以下。太行山山前断裂带作为太行地块与平原地块的分界,其主体形成于早第三纪,晚第三纪至第四纪仍在强烈活动。结合近期形变与地震活动等资料,我们认为该断裂带南端的邯郸断裂是需要进一步加强监视的危险地段。  相似文献   

6.
水系的分形特征与红河断裂带活动性关系初探   总被引:4,自引:1,他引:4  
将分形几何学的原理和方法,应用于红河断裂带中南段断错水系的研究。发现断错水系的分维值变化可以反映当地新构造活动的的变化趋势,中段水系的分维值总体上高于南段,南段内部分维值有一定的变化,反映出断裂带的构造活动性由中段尾部向两头增强的趋势。  相似文献   

7.
东昆仑活动断裂带及其强震活动   总被引:17,自引:0,他引:17  
刘光勋 《中国地震》1996,12(2):119-126
本文在简述东昆仑活动断裂带的构造背景与演化历史的基础上,重点叙述了该活动断裂带的展布,几何结构,第四纪运动和强震活动等特征,指出,这是一条具有长期演化历史,深部构造背景和第四纪乃至全新强烈活动的断裂带。因而在我国大地构造演化,尤其在青藏高原隆起形成,占有重要地位,同时,它还是我国西部地区一条主要的强震活动构造带,根据现代强震活动记录和在全带新发现的多期全新世古地震及其地表破裂带,分析了大震在断裂带  相似文献   

8.
浑江断裂带及水系的分形特征和构造活动性研究   总被引:6,自引:0,他引:6  
应用分开有几何学方法对浑江断裂带及水系进行了分形特征研究。计算结果表明,浑江断裂带具有较强的活动性,而且次级NNE向断层比NE和NW向断层活动性更强,结合地震活动属于 质地貌,构造应力场等方面的分析。探讨了该断裂带的活动性及区域新构造运动特征。  相似文献   

9.
广西地区的水系展布与活动断裂及新构造应力场的关系   总被引:3,自引:0,他引:3  
尹克坚 《华南地震》1995,15(1):62-67,94
对广西以及邻区的部分河流进行了统计分析,认为广西水系较好地反映了广西断裂的展布和活动性,一些原称隐伏断裂应当看成活动断裂,文章还对水系统计法进行了讨论,指出该方法在理论上存在某些缺陷,在实际操作上也存在较多问题。  相似文献   

10.
<正>为了研究龙日坝断裂带在青藏高原东缘应变分配中的作用和分析平行走滑断裂带是否会像2008年汶川8.0级地震造成两条平行断裂的共同破裂,开展了龙日坝断裂晚第四纪滑动速率和古地震序列的详细定量研究。野外调查表明,龙日坝断裂带位于龙门山以西约200 km,与龙门山断裂带大致平行,它由两条近平行的断裂(毛尔盖断裂和龙日曲断裂)组成。其中毛尔盖断裂主要沿着毛尔盖河和羊拱沟的北侧基岩山坡展布,发育断错山脊和断错水系,其晚第四纪活动表现为右旋走滑;龙日曲断裂主要沿龙日曲河和雀儿  相似文献   

11.
北部湾地震的震源机制及地震地质条件   总被引:3,自引:0,他引:3  
对北部湾地震的震源机制解和地震地质条件进行了详细分析,认为靖西-崇左断裂带过震中的北北西向断层为发震断裂,四会-吴川断裂带过震中的北东东向断层为控震构造,震源构造应力场的主压应力方向为北西-南东向,发震断层的活动方式既有垂直差异运动又有走滑运动。  相似文献   

12.
兰州地区活动构造的基本特征   总被引:5,自引:0,他引:5  
兰州地区发育了NWW向和NWW向2组主导性活动构造带。大致以河口为界,东部地区主要为NWW向的马衔山-兴隆山左旋逆走滑活动断裂系,其新活动明显,是区内的主要控震断裂,1125年兰州7级地震就发生在其中的马衔山北缘断裂带的西端。河口以西为拉脊山北缘断裂和庄浪河断裂等1组NWW向的弧形逆冲断褶带,变形方式以断裂扩展褶皱为主,其新活动可能导致了138年金城-陇西63/4级地震、1440年永登61/4级地震和1995年永登5.8级地震的发生。兰州市区所在的兰州盆地则夹持在上述2组活动构造之间,其内同样发育了NWW向和NWW向的次级断裂,如刘家堡断裂、金城关断裂、雷坛河断裂及深沟桥断裂等,其上具有孕育和发生中强震的构造条件。  相似文献   

13.
The Yarlung Tsangbo fault zone, one of the most important geological interfaces in the Yarlung Tsangbo suture zone which is a huge geotectonic boundary with nearly east-west-trending in southern Tibet Plateau, has undergone a long-term tectonic evolution. Studying this fault zone can help us understand the development and evolution history of the suture zone and the tectonic mechanism of subduction-collision about the Tibet Plateau, so it has always been a hot topic in the field of geology. Most of existing data suggest that the current tectonic activity in southern Tibet is given priority to the rift system with nearly north-south-trending, and the Yarlung Tsangbo fault zone with nearly east-west-trending has relatively weaker activity since late Quaternary. There are only some evidences of Holocene activity found in the Lulang town section near eastern Himalayan syntaxis, and there are few reports about the reliable geological evidences of late Quaternary activity of the section on the west of Milin County of the fault zone. Based on image interpretation, field investigation and chronological method, we found several fault profiles along the Yarlung Tsangbo fault zone near the Angren Lake in this study. These profiles reveal that loose fault gouge has been developed on the fault plane which nearly extends to the surface and offsets the loess sediments and its overlying alluvial-proluvial gravels. The loess is characterized by coarser grains, higher content of fine sand and tiny small gravels. The results of the two OSL dating samples collected in the loess are(94.68±6.51)ka and(103.84±5.14)ka respectively, showing that the loess revealed at the Angren site should be the middle-late Pleistocene sand loess distributed on the high-terraces along the Yarlung Tsangpo River. Consequently, the Angren segment of the Yarlung Tsangpo fault zone is active since the late Quaternary. In addition, synchronous left-lateral offsets of a series of small gullies and beheaded gullies can be seen near the profiles along the fault, which are the supporting evidence for the late Quaternary activity of the fault. However, the segment with obvious geomorphology remains is relatively short, and no evidence of late Quaternary activity have been found in other sections on the west of Milin County of the Yarlung Tsangpo fault zone. Existing data show that, in the southern Tibet, a series of near NS-trending rift systems are strongly active since the late Quaternary, cutting almost all of the near east-west-trending tectonic belts including the Yarlung Tsangpo fault zone. In addition, majority of the earthquakes occurring in southern Tibet are related to the NS-trending rift systems. Tectonic images show that the Angren segment locates between the Shenzha-Dingjie rift and the Dangreyong Lake-Gu Lake rift. These two adjacent rifts are special in the rift system in southern Tibet:Firstly, the two rifts are located in the conversion position of the trend of the whole rift system; Secondly, the size of the two rifts varies significantly between the north side and the south side of the Yarlung Tsangbo fault zone. Thirdly, the Shenzha-Dingjie rift seems to be of right-lateral bending, while the Dangreyong Lake-Gu Lake rift shows left-lateral bending. These characteristics may lead to the fact that the amount of absorption and accommodation of the rift activities in the north side of the Yarlung Tsangbo fault zone is larger than that in the south side during the migration of the plateau materials, leading to the differential movement of the block between the two sides of the fault zone. Therefore, the Yarlung Tsangbo fault zone possesses the accommodating tectonic activity, of course, the intensity of this accommodating activity is limited and relatively weaker, which may be the reason why it is difficult to find large-scale tectonic remains characterizing the late Quaternary activity along the fault zone. The scale of the rift system in southern Tibet is systematically different between the two sides of the Yarlung Tsangbo fault zone, so it cannot be ruled out that there are also weak activities similar to the Angren segment in other sections of the fault zone.  相似文献   

14.
Tanlu fault zone is the largest strike-slip fault system in eastern China. Since it was discovered by aeromagnetics in 1960s, it has been widely concerned by scholars at home and abroad, and a lot of research has been done on its formation and evolution. At the same time, the Tanlu fault zone is also the main seismic structural zone in China, with an obvious characteristic of segmentation of seismicity. Major earthquakes are mostly concentrated in the Bohai section and Weifang-Jiashan section. For example, the largest earthquake occurring in the Bohai section is M7.4 earthquake, and the largest earthquake occurring in the Weifang-Jiashan section is M8.5 earthquake. Therefore, the research on the active structure of the Tanlu fault zone is mainly concentrated in these two sections. With the deepening of research, some scholars carried out a lot of research on the middle section of Tanlu fault zone, which is distributed in Shandong and northern Jiangsu Province, including five nearly parallel fault systems, i.e. Changyi-Dadian Fault(F1), Baifenzi-Fulaishan Fault(F2), Yishui-Tangtou Fault(F3), Tangwu-Gegou Fault(F4) and Anqiu-Juxian Fault(F5). They find that the faults F3 and F5 are still active since the late Quaternary. In recent years, we have got a further understanding of the geometric distribution, active age and active nature of Fault F5, and found that it is still active in Holocene. At the same time, the latest research on the extension of F5 into Anhui suggests that there is a late Pleistocene-Holocene fault existing near the Huaihe River in Anhui Province. The Tanlu fault zone extends into Anhui Province and the extension section is completely buried, especially in the Hefei Basin south of Dingyuan. At present, there is little research on the activity of this fault segment, and it is very difficult to study its geometric structure and active nature, and even whether the fault exists has not been clear. Precisely determining the distribution, active properties and the latest active time of the hidden faults under urban areas is of great significance not only for studying the rupture behavior and segmentation characteristics of the southern section of the Tanlu fault zone, but also for providing important basis for urban seismic fortification. By using the method of shallow seismic prospecting and the combined drilling geological section, this paper carries out a detailed exploration and research on the Wuyunshan-Hefei Fault, the west branch fault of Tanlu fault zone buried in Hefei Basin. Four shallow seismic prospecting lines and two rows of joint borehole profiles are laid across the fault in Hefei urban area from north to south. Using 14C, OSL and ESR dating methods, ages of 34 samples of borehole stratigraphic profiles are obtained. The results show that the youngest stratum dislocated by the Wuyunshan-Hefei Fault is the Mesopleistocene blue-gray clay layer, and its activity is characterized by reverse faulting, with a maximum vertical offset of 2.4m. The latest active age is late Mesopleistocene, and the depth of the shallowest upper breaking point is 17m. This study confirms that the west branch of Tanlu fault zone cuts through Hefei Basin and is still active since Quaternary. Its latest activity age in Hefei Basin is late of Middle Pleistocene, and the latest activity is characterized by thrusting. The research results enrich the understanding of the overall activity of Tanlu fault zone in the buried section of Hefei Basin and provide reliable basic data for earthquake monitoring, prediction and earthquake damage prevention in Anhui Province.  相似文献   

15.
田勤俭  张军龙 《地震地质》2008,30(1):324-332
阿尔泰构造带的活动断裂主要为NW—NNW向。按构造位置可分为阿尔泰西缘活动断裂带、阿尔泰中央活动断裂带和阿尔泰东缘活动断裂带。阿尔泰东缘活动构造带由科布多(Hovd)活动断裂带、哈尔乌苏湖(Har Us)活动断裂带2条大型右旋走滑活动断裂和中间的挤压盆地带构成。在2条走滑断裂带上,前人发现多处地震地表破裂带。通过对阿尔泰东缘构造带中南段地区的野外调查,在哈尔乌苏湖断裂带中段的Jargalant断裂、科布多断裂带南段的Tugen gol断裂上新发现地震地表破裂带。其中,沿Jargalant断裂地震地表破裂带长约50km,右旋位错量约4~5m,是一次规模大、活动较新的破裂事件。可见,在阿尔泰东缘活动断裂带的不同断裂段上均有保存较好的地震地表破裂,显示阿尔泰东缘是活动强烈的地震构造带  相似文献   

16.
试论安宁河断裂带新活动的分段性与地震活动   总被引:4,自引:0,他引:4  
唐荣昌  黄祖智 《地震研究》1989,12(4):337-347
本文根据近几年来对安宁河断裂带的野外调查资料,结合地震活动性、地壳形变、断层带中断层泥SEM特征分析,着重讨论了安宁河断裂带活动性的分段特征及其与地震活动的关系。资料表明,断裂带在晚更新世以来活动的强弱与地震活动在时间上和空间上分布的不均匀性有较好的一致性,即地震活动的强度、频度,严格受断裂带在晚更新世以来的活动强度、活动方式的制约。研究活动断层的活动分段性,对判定地震危险区及工程稳定性评价具有重要的科学意义和应用价值。  相似文献   

17.
利用地震矩张量反演阿尔金断裂带现今运动学特征   总被引:5,自引:0,他引:5       下载免费PDF全文
王卫东  李少睿 《地震地质》1999,21(2):76-175
利用地震矩张量反演断裂形变带运动学参数的方法,应用于阿尔金断裂带现今运动学特征的研究。结果表明,阿尔金断裂带以沿S14°E的压缩运动为主,压缩速率为1.13mm/a;同时,断裂带还以0.17mm/a的速率发生左旋剪切运动  相似文献   

18.
徐叶邦 《地震学报》1991,13(3):372-379
活动断裂带中地震时空分布的信息维 D1避免了容量维 D0的缺陷,考虑了每一地震事件对信息所作的贡献,从新的角度反映了地震分布时空结构特征.计算表明,炉霍大震前鲜水河断裂带地震分布时间结构信息维 D1=0.1051,这是该区大震活动的一个参考性判据.安宁河断裂带十七年现今地震分布时间结构信息维:北段,D1(tN)=0.1363;南段,D1(tS)=0.06710.地震空间分布信息维:北段,D1(KN)=1.053;南段,D1(Ks)=0.7758.南北两段分属信息维维数不同的两个自相似系统.南段地震活动自组织程度较高.这有助于强震重点监测区内主要危险段的判定地震时空分布 D1特征探索对于活断层研究以及地震预报都有一定的意义.   相似文献   

19.
兰州马衔山-兴隆山活动断裂系的构造变形特征和机制   总被引:8,自引:0,他引:8  
详细考察获得了兰州马衔山—兴隆山活动断裂系4条断裂的几何细结构、新活动性等定量资料。其中马衔山北缘断裂为一条规模大、活动性强的全新世逆左旋走滑断裂,而马衔山南缘断裂、兴隆山南缘断裂和兴隆山北缘断裂等其它3条断裂均为其伴生的逆断裂,为晚更新世活动断裂。它们在深部均可以归并到马衔山北缘断裂这一主走滑断裂带上,是兰州地区重要的控震断裂,影响和制约着本区的地震活动。  相似文献   

20.
通过收集鄂尔多斯块体西缘固定地震台网2010年6月至2017年8月的近场地震资料,选择符合剪切波分裂分析的14个台站记录的共137个有效事件波形,得到了剪切波分裂参数,即快剪切波(简称快波)偏振方向和慢剪切波(简称慢波)时间延迟.结果表明,研究区的快波偏振方向和慢波时间延迟具有明显的分区特征,快波偏振方向主要与构造应力场方向或者断层走向大体一致.鄂尔多斯西缘紧邻块体边界的台站,快波偏振方向自北向南呈现NS、NNE、NE向的变化,与青藏高原东北缘主压应力方向变化基本一致.银川地堑东西两侧的快波偏振方向有差异,东侧区域主要受青藏高原NNE向挤压和黄河-灵武断裂共同影响,而西侧区域可能受到阿拉善块体与鄂尔多斯块体之间的NW方向的主张应力和阿拉善块体内部应力分布的影响;鄂尔多斯块体、阿拉善块体与青藏高原的交汇区快波优势偏振方向为NE向,与青藏高原东北缘主压应力方向一致;海原断裂带及以南区域快剪切波优势偏振方向为WNW向,与断裂走向基本一致,较好的说明了海原断裂带为活跃的活动断裂.构造与断裂分布都是控制快波偏振方向的主要因素,走滑断裂上的台站快波偏振方向与断裂走向一致,表明这些台站主要受到断裂的强烈影响;走滑断裂附近的个别台站快波偏振方向呈现与构造应力场一致的方向,表明几乎没有受到断裂的影响.鄂尔多斯、阿拉善与青藏高原的交汇区平均时间延迟高于其他地区,反映了青藏高原在NE向运动过程中,受到稳定的鄂尔多斯块体阻挡作用,导致了交汇区地壳介质各向异性程度增加.以海原断裂带到六盘山断裂带为界,其两侧区域的各向异性差异性明显,揭示了应力与介质特性的差异,暗示其邻近区域,特别在海原断裂带东端到六盘山断裂带与鄂尔多斯块体西缘交汇区域,可能有较高的强震危险背景.本研究还对该区域的地壳和上地幔的耦合问题进行了初步讨论.  相似文献   

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