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海原活动断裂带的古地震与强震复发规律 总被引：16，自引：0，他引：16
海原断裂是中国西部的一条重要活动走滑断裂带, 1920年沿该带发生的8.5级强震形成了230 km长的地表破裂带和10 m的左旋走滑位移. 为了揭示这条重要发震断裂的强震活动规律, 沿断裂带的3个段落开挖了17个探槽, 揭示了大量的古地震事件, 并结合前人的研究结果, 利用古地震分析的逐次限定方法研究了海原断裂带的强震复发规律. 研究发现, 海原断裂带的3个段落具有分段差异的古地震活动历史; 古地震破裂有3种尺度, 即单段破裂、双段破裂和全段破裂. 另外, 整个海原断裂带的古地震丛集现象也十分明显, 第1丛集期在距今4600~6300 a期间, 第2丛集期发生在距今1000~2800 a期间. 海原断裂带的古地震活动习性对于认识大陆走滑断裂的破裂特征和强震复发规律具有十分重要的意义. 相似文献
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海原断裂是中国西部的一条重要活动走滑断裂带，1920年沿该带发生的8.5级大震形成了长达230 km的地表破裂带和10 m的左旋走滑位移. 近10余年来，国内外学者对海原断裂开展了古地震研究，揭示出大量的古地震事件，为研究该断裂带上强震复发规律提供了重要的基础资料.本文利用这些古地震资料，采用泊松模型和布朗过程时间模型（Brownian passage time model），并考虑海原断裂带3个段落组合的不同尺度的破裂（单段破裂、双段破裂和全带破裂），经加权分析计算得到了海原断裂带未来百年强震（M6.7）复发的可能性及其震级分布. 计算结果表明，海原断裂带未来百年M6.7地震发生的可能性为0.035. 相似文献
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四川活动断裂带的基本特征 总被引：6，自引：0，他引：6
根据大量的实际资料，总结了四川活动断裂带的基本特征：即大致以北东向龙门山断裂带与北西向荣经－马边－盐津断裂带为界，显示了西强东弱的分区活动特点。断裂活动在时间、空间和强度上都具有明显的不均匀性与分段活动特征；晚更新世～全新世以来发生的强震破裂活动大都是沿袭先存断裂进行的，从古地震研究及较短时间尺度（有历史地震记录以来）来看，反映出断层上的位移是以一种地震构造脉冲形式出现 相似文献
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2018年5·12汶川地震后,龙门山断裂带的大地震活动特征一直是倍受关注的科学问题.而探槽古地震研究是最直接揭示活断层带晚第四纪大地震活动规律的重要途径.本文通过系统总结龙门山断裂带近十年来探槽古地震研究成果,全面分析了龙门山断裂带不同段落的晚第四纪大地震活动与复发特征.结果显示：龙门山断裂带的大地震活动具有明显的分段性,北川—映秀断裂和江油—灌县断裂中段（包括小鱼洞断裂）是全新世以来,最为活跃的段落,约距今6000年以来,发生过3次位移量近似相等的事件,分别发生在5920—5730 cal BP和3300—2300 cal BP,大地震活动具有3000年左右的准周期复发特征;北川—映秀断裂的北段具有独立破裂的能力,该段汶川地震前一次事件发生在大约665—1030 AD,可能是历史上记载的942 AD地震事件,另一次事件发生在8240—7785 BC;江油—灌县断裂的南段（大川—双石断裂）发震能力明显弱于断裂带中段和北段.现有古地震数据表明,沿北川—映秀断裂,除汶川地震以外,并未显示出不同段落间在全新世期间存在级联破裂的证据,这可能意味着2008年汶川M8地震是龙门山断裂带上罕见的巨大地震事件.另外,青川断裂上探槽揭露的古地震变形事件不像是断裂直接位错的结果,更可能是被动响应北川—映秀断裂右旋位错的现象. 相似文献
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沿内蒙大青山山前活动断裂进行野外调查及探槽开挖的研究结果表明 ,该断裂西部地段及东部地段的最新活动时期在全新世中期以后及全新世晚期以前 ;中部地段在全新世晚期强烈活动 ,公元 84 9年包头地震的地表破裂沿该段展布。大青山山前台地与断层陡坎分布、洪积扇类型及河流阶地断错等地貌特征、全新世晚期断裂活动范围、沿断裂带探槽开挖获得的古地震事件对比 ,以及现今中小地震震中分布表明 ,全新世晚期大青山山前断裂的活动以土左旗为界 ,该界以西全新世晚期断裂强烈活动 ,该界以东全新世晚期断裂活动不明显。全新世时期大青山山前断裂的活动显示了由东向西的迁移 相似文献
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通过对野外调查资料的分析认为:库赛湖—玛曲断裂带东、西大滩段全新世以来具有多次强烈活动,表现为断错晚第四纪地层,断错山脊、水系、河流阶地以及冰水扇等一系列地貌现象。根据对断裂带上古地震破裂带的研究,全新世以来在该段曾发生过三次7.5级左右的古地震事件。 相似文献
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郯庐断裂带是中国东部重要的活动断裂带和边界构造带,其鲁苏段全新世活动断层的空间展布和古地震序列是地学关注的焦点问题,也是准确评价区域地震危险性的重要参数.以往研究工作多集中在郯庐断裂带地表地貌现象明显且有强震记录的山东段,而江苏段则研究程度相对较低,有关郯庐断裂带江苏段全新世活动断层范围和古地震序列问题存在争议.本文利用野外地质地貌调查、浅层地震勘探、钻孔联合剖面以及古地震探槽等多层次综合方法,重点开展郯庐断裂带江苏段全新世活动断层的分布和古地震序列研究.结果显示全新世时期,安丘-莒县断裂是郯庐断裂带江苏段的主要活动断层,且江苏全段该断层都是全新世活动断层.通过对比宿迁闸-皂河镇断裂南北安丘-莒县断裂的断层地貌和断层最新活动时间,并结合宿迁闸-皂河镇断裂在第四纪没有活动过等证据,推测该断层在全新世时期并不是区域阻碍破裂的断层.探槽揭示郯庐断裂带江苏段全新世两次古地震事件,事件Ⅰ限定在（6.2±0.3）-（13.4±0.7）ka B.P.之间,而事件Ⅱ限定在（2.5±0.1）ka B.P.到现今,全新世两次古地震间隔较长.基于构造类比法,安丘-莒县断裂具有深部孕震的构造特点,是区域未来强震的潜在发震构造. 相似文献
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《地震地质》2016,(4)
沿大型走滑断裂带经常发生导致多个断层段同时破裂的级联破裂地震事件。海原断裂带在1920年海原M 8地震时3个段同时发生破裂,干盐池拉分盆地即为其西段和中段的分段边界。沿该盆地内新生断层的古地震研究揭示了晚更新世末期以来的至少7次古地震事件证据,最新1次事件为1920年海原地震,1920年海原地震之前的1次事件可能与1092年历史地震对应。对比分析表明,这些事件可能均为超过8级的大地震,其复发呈现地震丛集与单个事件相间排列的规律,当前可能处于最近的1个地震丛集期内。该古地震序列与整个海原断裂带的大地震活动历史的对比表明,干盐池拉分盆地内新生断层在级联破裂地震事件发生时并非总是同时破裂,该断层是否参与破裂可能与该次级联破裂事件的震级大小有关。讨论整个走滑断裂带大地震活动历史时应避免仅依据具有一定规模的拉分盆地内部断层的破裂记录。 相似文献
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郯庐断裂带是中国东部最主要的一条活动断裂带。在该断裂带中部,沂沭断裂东地堑的潍坊—嘉山段中发育了1条长360km的全新世活动断裂带(F5),在该全新世断裂带的北段和中段分别发生了公元70年的安丘地震和公元1668年的郯城地震。2003年底我们考察沭河断裂带时,在莒县境内发现了1条长约7km的地震破裂带,作为活动断层应该归属于F5断裂带,但其是一条独立的地震破裂段还是归属于1668年郯城8.5级地震破裂带有待于进一步的研究。尽管如此,探槽揭示出的上覆未经破坏的地层的14C年代表明,该破裂带在(2140±190)aBP以来没有过活动,因此我们认为其作为1条独立破裂段的可能性较大 相似文献
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DEFORMATION CHARACTERISTICS AND KINEMATIC PARAMETERS INVERSION OF HAIYUAN FAULT ZONE BASED ON TIME SERIES INSAR 
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下载免费PDF全文 Located at the bend of the northeastern margin of Qinghai-Tibet Plateau, the Haiyuan fault zone is a boundary fault of the stable Alashan block, the stable Ordos block and the active Tibet block, and is the most significant fault zone for the tectonic deformation and strong earthquake activity. In 1920, a M8.5 earthquake occurred in the eastern segment of the fault, causing a surface rupture zone of about 240km. After that, the segment has been in a state of calmness in seismic activity, and no destructive earthquakes of magnitude 6 or above have occurred. Determining the current activity of the Haiyuan fault zone is very important and necessary for the analysis and assessment of its future seismic hazard.
To study activity of the Haiyuan fault zone, the degree of fault coupling and the future seismic hazard, domestic and foreign scholars have carried out a lot of research using geology methods and GPS geodetic techniques, but these methods have certain limitations. The geology method is a traditional classical method of fault activity research, but dislocation measurement can only be performed on a local good fault outcrop. There are a limited number of field measurement points and the observation results are not equally limited depending on the sampling location and sampling method. The distribution of GPS stations is sparse, especially in the near-fault area, there is almost no GPS data. Therefore, the spatial resolution of the deformation field features obtained by GPS is low, and there are certain limitations in the kinematic parameter inversion using this method.
In this study, we obtain the average InSAR line-of-sight deformation field from the Maomaoshan section to the mid-1920s earthquake rupture segment of the Haiyuan earthquake in the period from 2003 to 2010 based on the PSInSAR technique. The results show that there are obvious differences between the slip rates of the two walls of the fault in the north and the south, which are consistent with the motion characteristics of left-lateral strike-slip in the Haiyuan fault zone. Through the analysis of the high-density cross-fault deformation rate profile of the Laohushan segment, it is determined that the creep length is about 19km. Based on the two-dimensional arctangent model, the fault depth and deep slip rate of different locations in the Haiyuan fault zone are obtained. The results show that the slip rate and the locking depth of the LHS segment change significantly from west to east, and the slip rate decreases from west to east, decreasing from 7.6mm/a in the west to 4.5mm/a in the easternmost. The western part of the LHS segment and the middle part are in a locked state. The western part has a locking depth of 4.2~4.4km, and the middle part has a deeper locking depth of 6.9km, while the eastern part is less than 1km, that is, the shallow surface is creeping, and the creep rate is 4.5~4.8mm/a. On the whole, the 1920 earthquake's rupture segment of the Haiyuan fault zone is in a locked state, and both the slip rate and the locking depth are gradually increased from west to east. The slip rate is increased from 3.2mm/a in the western segment to 5.4mm/a in the eastern segment, and the locking depth is increased from 4.8km in the western segment to 7.5km in the eastern segment. The results of this study refine the understanding of the slip rate and the locking depth of the different segments of the Haiyuan fault zone, and provide reference information for the investigation of the strain accumulation state and regional seismic hazard assessment of different sections of the fault zone. 相似文献
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Earthquake probabilities and magnitude distribution (M ≥ 6.7) along the Haiyuan fault, northwestern China 总被引：2，自引：0，他引：2
冉洪流 《地震学报(英文版)》2004,17(6)
Introduction Haiyuan fault is a major seismogenic fault in north-central China. One of the most devastat-ing great earthquake in the 20th century occurred near Haiyuan in northwestern China on Decem-ber 16, 1920. More than 220 000 people were killed and thousands of towns and villages weredestroyed during the devastating earthquake. A 230 km long left-lateral surface rupture zone wasformed along the Haiyuan fault during the earthquake with maximum left-lateral displacement of10 m. Pale… 相似文献
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PALEOSEISMIC RECORDS OF LARGE EARTHQUAKES ON THE CROSS-BASIN FAULT IN THE SALT LAKE PULL-APART BASIN AND CASCADE RUPTURE EVENTS ON THE HAIYUAN FAULT 下载免费PDF全文
下载免费PDF全文 Cascade rupture events often occur along large strike-slip fault zone.The 1920 AD M 81/2 earthquake ruptured all 3 segments of the Haiyuan Fault,and the Salt Lake pull-apart basin is the boundary between the west and middle segment of the fault.The data of trenching and drilling reveal 7 events occurring since last stage of late Pleistocene,and the two youngest events are associated with the historical records of 1092 AD (possibly) and 1920 AD respectively.These events are all large earthquakes with magnitude M>8,and the recurrence of them is characterized by earthquake clusters alternating with a single event.Now it is in the latest cluster which may last about 1000 years.Comparison of the paleoseismic sequence of this study and previous results reveals that the cross-basin fault in the Salt Lake pull-apart basin does not always rupture when cascade rupture events occur along the Haiyuan Fault,and likely ruptures only when the magnitude of the events is large (maybe M>8).Though there are many advantages in paleoseismic study in pull-apart basin,we should avoid getting the paleoseismic history of major strike-slip fault zones only depending on the rupture records of inner faults in pull-apart basins with large scale (maybe a width more than 3km). 相似文献
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北祁连山东段活动断裂带古地震特征 总被引：5，自引：0，他引：5
根据古地震探槽剖面及断坎年代资料，综合分析了北祁连山东段活动为裂带的 震活动特征。沿断裂带的古地震具有非均匀性活动的特点，表现为活动期次的差异性、空间上的分段性和中段时间上的准周期性。 相似文献
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Paleoearthquake rupture behavior and recurrence of great earthquakes along the Haiyuan fault,northwestern China 总被引：16，自引：0，他引：16
ZHANG Peizhen MIN Wei DENG Qidong & MAO Fengying State Key Laboratory of Earthquake Dynamics Institute of Geology China Seismological Bureau Beijing China 《中国科学D辑(英文版)》2005,48(3):364-375
Paleoseismological studies have shown that indi-vidual past large-magnitude earthquakes can be recog-nized in the geological record and the timing betweenevents can be measured through Quaternary datingtechniques[1—6]. Thus, through paleoseismological st-udies, it is possible to determine age of each prehis-toric event so that recurrence intervals of large earth-quakes may be evaluated which provides a means toexpand the limited view of earthquakes offered by thehistorical and instrumental re… 相似文献
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Ran Hong-liu 《地震学报(英文版)》2004,17(6):671-677
In recent years, some researchers have studied the paleoearthquake along the Haiyuan fault and revealed a lot of paleoearthquake
events. All available information allows more reliable analysis of earthquake recurrence interval and earthquake rupture patterns
along the Haiyuan fault. Based on this paleoseismological information, the recurrence probability and magnitude distribution
for M≥6.7 earthquakes in future 100 years along the Haiyuan fault can be obtained through weighted computation by using Poisson
and Brownian passage time models and considering different rupture patterns. The result shows that the recurrence probability
of M
S≥6.7 earthquakes is about 0.035 in future 100 years along the Haiyuan fault.
Foundation item: Joint Seismological Science Foundation of China (103034) and Major Research “Research on Assessment of Seismic Safety” from
China Earthquake Administration during the tenth Five-year Plan. 相似文献
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Tang Rongchang Huang Zuzhi Zhou Rongjun Zhu Jiangang and Gong YuSeismological Bureau of Sichuan Province Chengdu China 《中国地震研究》1996,(1)
Based on geometric structure,active strength,and maximum seismic rupture length along the fault in the late Quaternary or Holocene,this paper presents the segmentation of main active faults in Sichuan Province and uses the recurrence probability model to predict the recurrence probabilities of strong earthquakes along each segment during next 30 years.The results indicate that earthquakes with M=7.0 or greater may happen along Qiajiao segment,Qianning segment,and Selaha segment of Xianshuihe fault zone,the segment from Xichang to Mianning and Yejidong segment of Anninghe fault zone; earthquakes with M=6.0 or greater may happen along the segment from Maowen to Caopuo of Longmenshan fault zone and Xiaoyanjing segment of Anninghe fault zone. 相似文献