祁连山中东段强震复发概率模型及未来强震地点预测

本文主要从祁连山中东段主要活动断裂带全新世以来古地震活动以及历史地震和现代地震的复发间隔入手，通过对强震复发间隔与平均复发间隔的比值(T/Ta)的数学处理，建立了区域强震复发所遵循的概率模型，并对未来强震的复发可能性和强震发生地点进行预测。结果表明，本地区未来最有可能的强震发生地点是老虎山-毛毛山断裂带的毛毛山-金强河段。     

京西北盆岭构造区强震复发概率模型及地震潜势的定量评估

基于京西北盆岭构造区活动构造的定量化研究成果 ,视强震复发间隔为一随机变量 ,借鉴NB模型的建模方法 ,结合强震复发过程中存在分形规律的思想 ,建立京西北模型———强震复发间隔的均一化值服从正态分布N(1.0 0 0 3,0 .2 4 6 4 2 ) ;京西北盆岭构造区未来可能发生地震概率较高的断裂是 :天镇 -阳高盆地北缘断裂、阳原盆地南缘断裂、延庆盆地北缘断裂辛韩段、矾山盆地北缘断裂燕水段、宣化盆地南缘断裂     

北祁连山-河西走廊大震危险区预测

以青藏块体北部的北祁连山-河西走廊地震构造带为研究对象,在系统收集整理该区主干活动断裂新活动性特征、断裂滑动速率、历史地震及古地震资料的基础上,结合现今地震活动性,采用地震空区、空段识别方法和地震活动b值空间图像扫描方法,分析了研究区内历史地震及b值的分布特征.结果显示,该区的榆木山北缘断裂离逝时间较长,应力积累程度较...     

应用断层的活动性分析民乐-张掖盆地及外围地区的强震危险性

依据民乐—张掖盆地及外围地区的断裂活动性对该盆地发生强震的危险地段和时间进行了预测．结果表明，盆地西缘的榆木山断裂西段和红崖堡断裂西段是发生强震的危险地段，在今后５０年内发生６．５≤ＭＳ≤７．０地震的可能性较大     

鲜水河断裂带北西段不同破裂源强震震级（M≥67）及复发间隔研究

鲜水河断裂带是四川西部一条晚第四纪强烈左旋走滑活动的构造带，历史上发生多次强震. 它与西北侧的甘孜—玉树断裂带一起，构成青藏高原东部的侧向滑移构造系统中的川滇活动地块的北边界——羌塘地块的东北边界. 鲜水河断裂带北西段可以分成4个段落，每一段落均可作为一个独立的基本破裂单元而发生地震破裂，亦有可能发生不同尺度的多段联合瞧裂. 对鲜水河断裂带北西段不同尺度破裂的震级及复发间隔进行研究. 根据该地区的地质、地球物理、测量及地震等方面的资料，结合我国强震复发的特点，分析了拉分盆地内部的滑动速率分布，以确定各段落的等效长度和倾向宽度，从而建立适合我国大陆走滑断裂的面波震级与断裂发震面积的关系式；进而运用地震矩方法，考虑断层之间的相互作用，结合专家意见建立了该段的矩平衡断裂破裂模型；最后，给出了鲜水河断裂带北西段各破裂源特征化地震的复发间隔、震级大小和不确定性，以及他与中小地震的联合震级分布. 结果表明，鲜水河断裂带北西段较易发生单段破裂，复发间隔在100～150年左右.     

鲜水河断裂带北西段不同破裂源强震震级（M≥67）及复发间隔研究

鲜水河断裂带是四川西部一条晚第四纪强烈左旋走滑活动的构造带，历史上发生多次强震. 它与西北侧的甘孜—玉树断裂带一起，构成青藏高原东部的侧向滑移构造系统中的川滇活动地块的北边界——羌塘地块的东北边界. 鲜水河断裂带北西段可以分成4个段落，每一段落均可作为一个独立的基本破裂单元而发生地震破裂，亦有可能发生不同尺度的多段联合瞧裂. 对鲜水河断裂带北西段不同尺度破裂的震级及复发间隔进行研究. 根据该地区的地质、地球物理、测量及地震等方面的资料，结合我国强震复发的特点，分析了拉分盆地内部的滑动速率分布，以确定各段落的等效长度和倾向宽度，从而建立适合我国大陆走滑断裂的面波震级与断裂发震面积的关系式；进而运用地震矩方法，考虑断层之间的相互作用，结合专家意见建立了该段的矩平衡断裂破裂模型；最后，给出了鲜水河断裂带北西段各破裂源特征化地震的复发间隔、震级大小和不确定性，以及他与中小地震的联合震级分布. 结果表明，鲜水河断裂带北西段较易发生单段破裂，复发间隔在100～150年左右.     

南北地震带北段主要断层的分区强震危险性评估

根据时间-震级可预测模式研究中国南北地震带北段断裂系统的地震复发规律,利用历史地震记录和断层滑动速率资料计算得出区域时间可预测统计模型和震级可预测统计模型,并对4个主要潜在震源区在未来10年内的强震复发危险性进行概率评估。计算结果表明,危险性最高为S1区(海原断裂带),其综合危险率K值为0.841,预测下次主震为6.9级;其次为S2区(天桥沟-黄羊川、香山-天景山、六盘山断裂带等),K值为0.480,预测下次主震为6.4级;S3区(祁连山构造带)和S4区(西秦岭构造带)远低于S1和S2区。按照危险程度排序的前2位均位于东祁连山-六盘山构造带。     

榆木山北缘断裂现今构造活动特征及其对青藏高原北东扩展的构造地貌响应

榆木山北缘断裂位于祁连山逆冲断裂带中部,是榆木山隆起与河西走廊之间的分界断裂。探究榆木山北缘断裂的构造活动,有助于进一步了解祁连山向N的扩展过程以及青藏高原向NE方向推挤的机制。文中主要从断层滑动速率、古地震活动习性和构造变形3个方面总结了榆木山地区近20多年以来的研究成果。通过遥感影像解译、野外地质调查、断错位移测量及地貌面年龄测定等方法和手段,估算了榆木山北缘断裂典型位错点的逆冲滑动速率为(0.55±0.15)mm/a;左旋滑动速率为(0.95±0.11)mm/a。认为前人提出的"骆驼城陡坎"并非断层活动的产物,而是古代引水工程或水利灌溉工程的遗迹,也就是说它不是公元180年表氏地震的地表破裂。通过DEM剖面所反映的山体形态,结合断裂各项特征,认为榆木山隆起是祁连山向N推挤的结果,断裂活动目前仍集中在榆木山北侧,山体的形态受断层扩展控制,山脉的扩展是1个垂向和侧向的过程,晚新生代以来榆木山持续隆升。     

青藏高原北部地区地震统计区划分及地震活动特征

地震统计区的划分是研究地震活动性的重要前提和基础,通过对青藏高原北部地区构造地质背景的分析,依据地球物理特征和强震活动特点,讨论和划分该区地震活动统计区,探讨研究区地震活动的复发特点、地震构造特征、潜在地震危险性及强度,分析研究区未来强震发生的强度和可能地点,结果表明,目前青藏高原北部地区处于第8个活跃期,仍存在发生强震的可能,且未来数年存在发生7级以上地震的可能,应密切东昆仑断裂带东段和祁连山中西段地区。     

鄂尔多斯地块北缘主要活动断裂晚第四纪强震复发特征

对鄂尔多斯活动地块北边界主要活动断裂的古地震研究、强震复发特征及异常分析,得到了晚第四纪的62次古地震,其中全新世期间33次.段落、断裂和断裂带3个层次的古地震复发特征有所差别,独立段落的强震序列多数遵循长短间隔复发的特征,而断裂和断裂带的随机或丛集特征更明显。“移动窗口测试”结果表明,色尔腾山山前断裂和乌拉山南缘断裂,随机偶合产生“异常接近/异常长间隔”的概率分别为64.4％和70％,各断裂的段落之间相互作用不明显;而整个断裂带,其概率为26.8％,断裂之间的相互作用明显。这种复发特征可能意味着地块整体运动对强震复发的影响。另外,色尔腾山山前断裂的乌句蒙口-东风村段和大青山山前断裂的土左旗-乌素图、呼和浩特段等3个段落离逝时间已超过平均重复间隔时间,是未来强震最可能发生的地点。     

PRESENT KINEMATICS CHARACTERISTICS OF THE NORTHERN YUMUSHAN ACTIVE FAULT AND ITS RESPONSE TO THE NORTHEASTWARD GROWTH OF THE TIBETAN PLATEAU

Qilian Shan and Hexi Corridor, located in the north of Tibetan plateau, are the margin of Tibetan plateau's tectonic deformation and pushing. Its internal deformations and activities can greatly conserve the extension process and characteristics of the Plateau. The research of Qilian Shan and Hexi Corridor consequentially plays a significant role in understanding tectonic deformation mechanism of Tibetan plateau. The northern Yumushan Fault, located in the middle of the northern Qilian Shan thrust belt, is a significant component of Qilian Shan thrust belt which divides Yumushan and intramontane basins in Hexi Corridor. Carrying out the research of Yumushan Fault will help explain the kinematics characteristics of the northern Yumushan active fault and its response to the northeastward growth of the Tibetan plateau.Because of limited technology conditions of the time, different research emphases and some other reasons, previous research results differ dramatically. This paper summarizes the last 20 years researches from the perspectives of fault slip rates, paleao-earthquake characteristics and tectonic deformation. Using aerial-photo morphological analysis, field investigation, optical simulated luminescence(OSL)dating of alluvial surfaces and topographic profiles, we calculate the vertical slip rate and strike-slip rate at the typical site in the northern Yumushan Fault, which is(0.55±0.15)mm/a and(0.95±0.11), respectively. On the controversial problems, namely "the Luotuo(Camel)city scarp" and the 180 A.D. Biaoshi earthquake, we use aerial-photo analysis, particular field investigation and typical profile dating. We concluded that "Luotuo city scarp" is the ruin of ancient diversion works rather than the fault scarp of the 180 A.D. Biaoshi earthquake. Combining the topographic profiles of the mountain range with fault characteristics, we believe Yumu Shan is a part of Qilian Shan. The uplift of Yumu Shan is the result of Qilian Shan and Yumu Shan itself pushing northwards. Topographic profile along the crest of the Yumu Shan illustrates the decrease from its center to the tips, which is similar to the vertical slip rates and the height of fault scarp. These show that Yumu Shan is controlled by fault extension and grows laterally and vertically. At present, fault activities are still concentrated near the north foot of Yumu Shan, and the mountain ranges continue to rise since late Cenozoic.     

兰州马衔山北缘断裂带古地震初步研究

兰州马衔山北缘断裂带为一条全新世活动断裂 ,大致由 4条次级断裂段组成 .沿断裂带发现了多期古地震事件 ,其活动具有时空不均匀性 .其中东段的马衔山段可以确定 2次古地震事件 ,距今 5850± 50 0aB .P .,2 0 60± 42 0aB .P .,复发间隔约 380 0a ;震级 7～ 7.5级左右 .中段的七道梁段发现 2次古地震事件 ,距今 1 682 0± 80aB .P .,1 0 80 0± 1 40aB .P ..西段的雾宿山咸水沟段可以确定一次古地震事件 ,其年代为 1 2 45± 560aB .P .,结合史料考证结果 ,认为就是 1 1 2 5年兰州 7级地震 .从古地震活动年代及复发间隔分析 ,马衔山北缘断裂带未来的强震危险段应为东段的马衔山段和西段的雾宿山咸水沟段 .     

SURFACE TRACKS AND SLIP RATE OF THE FAULT ALONG THE SOUTHERN MARGIN OF THE WUWEI BASIN IN THE LATE QUATERNARY

The fault along the southern margin of the Wuwei Basin, located in the eastern Hexi Corridor, NW China, plays an important role in the thrust fault system in the northern Qilian Mountains. The activities of this fault resulted in the generation of the Gulang earthquake(M_S8.0) in 1927. Based on remote sensing image interpretation, geological and geomorphic observations in the field and ¹⁴C geochronological dating results, we conducted a detailed research on the geometry and kinematics of the fault. According to the discontinuous geometric distribution and variable strike directions, we divide this fault into 5 segments: Kangningqiao Fault(F₁), Nanyinghe Fault(F₂), Shangguchengcun-Zhangliugou Fault(F₃), Tajiazhuang Fault(F₄)and Yanjiazhuang Fault(F₅). Results indicate that this fault, with a total of 60km long trace at the surface, has been active since the late Pleistocene. It behaves predominantly as a thrust fault and is accompanied with a locally sinistral strike-slip component along the Nanyinghe Fault(F₂). Intensive activities of this fault in Holocene have caused extensive occurrence of dislocated landforms along its strike. Some measured displacements of the dislocated geologic or geomorphic units, combined with the ¹⁴C dating results, yield a vertical slip rate of (0.44±0.08)mm/a on this fault in Holocene, and a sinistral strike-slip rate of (1.43±0.08)mm/a on the Nanyinhhe Fault (F₂) in late Pleistocene.     

Rupture Property of the 1927 Gulang Ms8.0 Earthquake and Numerical Simulation of Rupture Mechanism

INTRODUCTIONThe1927GulangMS8.0earthquake is a severe earthquake followed the HaiyuanMS8.5earthquake of1920inthe Qilian Mt._Hexi Corridor earthquake zone.The most severely hit region wasaround Gulang and Liangzhou(the present Wuwei)of Gansu Province,with a…     

Rupture Property of the 1927Gulang Ms8.0 Earthquake and Numerical Simulation of Rupture Mechanism1

The 1927 Gulang M_S8.0 earthquake is a severe earthquake that followed the Haiyuan M_S8.5 earthquake of 1920 in the Qilian Mt._Hexi Corridor earthquake zone. There are divergences of opinion in the previous studies about the rupture properties of the earthquake. Based on trenching and field investigation, and analysis of historical data, we hold that the earthquake resulted from the joint process of the Tianqiaogou_Huangyangchuan fault, Dongqingding segment of the Huangcheng_Shuangta fault and the Wuwei_Tianzhu buried fault, which constitute the Gulang nappe. By finite_element numerical simulation on the deformation mechanism of Gulang nappe, it is found that the stress and strain mainly concentrate in the western segment of the Tianqiaogou_Huangyangchuan fault, the Dongqingding segment of the Huangcheng_Shuangta fault, and the Gulangxia segment of the Wuwei_Tianzhu buried fault and the Gulang_Shuangta fault. The stress concentration coincides with the distribution of the earthquake surface rupture. It also proves that the earthquake is an outcome of the Gulang nappe activity as a whole.     

祁连山北缘玉门-北大河断裂晚第四纪活动特征

通过卫星影像解译、野外实地调查并结合前人研究成果,对位于祁连山北缘的玉门—北大河断裂晚第四纪构造活动特征进行研究。结果表明,玉门—北大河断裂为一条全新世活动的逆冲断裂,该断裂西起玉门青草湾,向东经老玉门市、大红泉止于骨头泉,全长约80km,整体走向NWW。根据断裂的几何结构及活动习性可将其分为三段:东段构造形态简单连续,为逆冲断层陡坎为主的古地震地表破裂带;中段结构复杂,由多条次级断层组成,以逆冲扩展为主;西段未出露地表而成为盲断裂-褶皱带。通过对断层陡坎差分GPS测量及相应地貌面年代测试,得到断裂晚更新世以来逆冲速率约为(0.73±0.09)mm/a。     

川滇地区若干活动断裂带整体的强地震复发特征研究

我们根据历史地震资料，采用统计学方法研究了川滇地区7条活动断裂带整体的强地震复发特征。结果表明，这7条断裂带的强地震复发表现出趋于随机的、随机的、以及丛集的行为，复发过程不具有良好的准周期性，也不存在强度－时间或者时间－强度的相依性。组成断裂带的强震破裂段落的数量越多，复发过程就越复杂。相对的地震活跃期与平静期交替出现。其中，活跃期内地震复发间隔分布的离散性较大，可用Weibull分布近似描述；而平静期的持续时间分布的离散性较小，可用正态等分布近似描述。不同相对活跃期的持续时间及强震的数量差别很大，导致相对活跃期并非准周期重视。因此，基于断裂带整体强震复发间隔分布的中长期危险性概率评估仍然面临一定的困难。     

2019年四川荣县MS4.9地震序列监测与活动特征研究

通过对荣县M_S4.9地震震中及附近地区地震监测、地震地质、地震活动背景和区域地震活动性的分析表明,荣县M_S4.9地震震前经历了区域地震平静至活跃、再发震的过程,该序列为正常的震群型,震中区及其附近的华蓥山断裂地震带和马边地震带的震后地震学参数均正常。荣县M_S4.9地震发震断裂为荣县-威远基底断裂,华蓥山断裂带及其附近地区2018年开始的5—6级地震活跃与川西地区东昆仑断裂带2017年8月九寨沟M_S7.0强震的发生存在呼应关系。      

Double Difference Location of the Mainshock and Aftershocks of the Hutubi MS6.2 Earthquake That Occurred on December 8, 2016

The mainshock and aftershocks of the Hutubi M_S6.2 earthquake on December 8, 2016 were relocated by applying the double difference method, and we relocated 477 earthquakes in the Hutubi region.The earthquake relocation results show that the aftershocks are distributed in the east-west direction towards the north side of the southern margin of the Junggar Basin fault, and are mainly distributed in the western region of the mainshock. The distance between the mainshock after relocation and the southern margin of the Junggar Basin fault is obviously shortened. Combined with the focal mechanism and the spatial distribution of the mainshock and aftershocks, it is inferred that the southern margin of the Junggar Basin fault is the main seismogenic structure of the Hutubi earthquake.