5.12汶川地震断层的同震位移构造意义与运动学模型

5.12汶川8.0级地震断层的同震位移方式、大小和空间变化为检验断层几何学、运动学与动力学分析理论与方法提供了一个现实范例。本文通过对汶川8.0级地震断层同震位移的几何学、运动学特征和可能的深部过程分析,并考虑到地震动力作用的影响,探讨了断层同震位移的地质意义和断层运动学模型问题,继而讨论了汶川8.0级地震过程中所呈现出的断层构造变形的现象对断裂构造分析的有关理论和方法的启示。提出了如下初步认识:(1)根据地震破裂面两侧地表高程差确定的断层垂直同震位移,并不完全是深部震源破裂的构造位移扩展到地表所致,而是包含了地震动力作用对断层破裂面两侧深部岩体的结构损伤破坏(膨胀)强烈程度差异所形成的非构造位移;(2)汶川地震的发震断层走滑-逆冲位移大小和方式的空间变化,可以用区域稳态构造应力和地震动力的联合作用给予合理解释,即断层的逆冲位移成分可以归因于为垂直断层的南东向的区域构造挤压应力作用之结果,而水平走滑位移则与震源体破坏过程形成的地震动力作用方向与不同区段断层的交角变化所致,即震源体上方映秀-北川断层南段和彭灌-江油断层,无论是区域构造应力,还是地震动力,都与断层走向近于直交,因此,断层以逆冲为主;而映秀-北川断...     

2014年5月云南盈江M_S5.6、M_S6.1地震发震构造分析

2014年5月云南省盈江县先后发生MS5.6、MS6.1地震,为确定它们的发震构造及其所反映的区域活动构造格局,笔者围绕该区开展了地震烈度调查、活动构造遥感解译、地质构造及构造地貌野外调查、震源机制解及余震分布资料分析等工作。调查与分析表明,两次地震的宏观震中均位于盈江县勐弄乡麻栗坡村附近,但发震断层明显不同。前者为NE走向左旋走滑的昔马—盘龙山断裂,后者为近SN向右旋走滑的苏典断裂。历史地震资料显示,盈江地区的地震活动多以5~6级的中-强震为主,并具有明显的群发性和沿SN向断层迁移的特征。在实皆断裂及滇西内弧带的共同作用下,腾冲地块内以大盈江断裂为界,北部主要发育近SN向右旋走滑断裂,南部则以NE向左旋走滑断裂为主,其中近SN向断层晚第四纪活动性更强。     

汶川Ms8级地震形成的擦痕形迹及其意义探讨

2008年5月12日14时28分(北京时间)中国四川省汶川县境内发生里氏80级地震。北川-映秀断裂是汶川Ms8级地震的发震断裂之一,以逆(右行)走滑活动为主,延伸长约220 km,活动强度大于其他两条断裂。主震在北川-映秀地表破裂带局部地点形成清晰的擦痕,它的位置和规模可能是深部破裂滑动量峰值在地表的响应。根据断层擦痕反映的应力场及位移与破裂长度关系等特征,将北川-映秀破裂带分为虹口段、北川段、南坝段。虹口段长度约22~45 km,同震位移量约45 m,σ1呈NWW-NW向,至少经历了三期活动,第三期逆冲活动强度最大,改造前两期逆(右行)走滑活动,它们的形成可能均与本次主震相关;北川段长约90~100 km,同震位移量约35 m,σ1呈NWW向近水平,活动强度弱于虹口第三期;南坝段长约35~50 km,同震位移量约25 m,以NWW向近水平挤压为特征,σ1方位角与中、南段相差约180°,活动强度与南段前两期相近。     

阿尔金断裂新生代构造活动的两阶段性——来自地震属性分析的证据

自新生代以来,柴达木盆地西北缘各构造单元受青藏高原持续挤压和阿尔金断裂走滑的影响,构造变形复杂,发育有多种不同性质,不同规模的断裂.地震属性技术是三维(3D)地震资料解释和构造分析的可靠依据,有助于客观、准确的揭示断裂的空间分布情况,是复杂地区地质解释的重要工具.本文利用地震属性技术,对位于阿尔金断裂南侧柴达木盆地西部的小梁山背斜深、浅层进行详细的断裂解译,发现该地区深部发育早期EW向逆冲断层;晚期由于阿尔金断裂大规模走滑的作用,形成由深部引发的NW向“楔形”逆冲断层,深部NW向断层的活动引发浅层的滑脱褶皱.综合分析认为阿尔金断裂新生代的活动分为早期隆升形成EW向斜向逆冲断层,晚期走滑运动发育控制现今背斜形态的NW向断层,具有两阶段活动的特点.     

2008年5月12日汶川地震（Ms8.0）地表破裂带的分布特征

2008年5月12日14时28分,青藏高原东缘龙门山地区（四川汶川）发生了Ms8.0级地震。震后野外考察表明,5.12汶川地震发生在NE走向的龙门山断裂带上,该断裂带晚新生代以来的逆冲速率小于1mm/a,GPS观察结果表明其缩短速率小于3mm/a。这次5.12汶川地震造成了多条同震逆冲地表破裂带,总体长约275km,宽约15km,发震断裂机制主要为逆冲作用（由NW向SE逆冲）伴随右旋走滑。地表主破裂带沿龙门山断裂带的映秀—北川断裂发育,长约275km,笔者称为映秀—北川破裂带,破裂带具有逆冲兼右旋走滑性质。地表次级破裂带沿龙门山断裂带的前缘断裂安县—灌县断裂南段发育,长80km,笔者称为汉旺破裂带,破裂带基本为纯逆冲性质。在这两条破裂带之间发育两条更次一级的同震地表破裂带：一条长约20km呈NE走向的地表破裂带,笔者称为深溪沟破裂带,由于这条破裂带靠近主破裂带南段,并且与主破裂带变形特征一致,因此,笔者将深溪沟破裂带划归映秀—北川破裂带;另一条长约6km呈NW走向、由SW向NE逆冲并兼有左旋滑动的地表破裂带,笔者称为小鱼洞破裂带,它连接映秀—北川破裂带和汉旺破裂带,成为侧向断坡。另外,在灌县—安县断裂东侧的四川盆地内,由都江堰的聚源到江油发育一条NE向的沙土液化带,它可能是四川盆地西部深部盲断裂活动的结果。同震地表破裂带的分布特征表明,龙门山断裂带活动断裂具有强烈的逆冲作用并伴随较大的右旋走滑,断裂向四川盆地扩展。在龙门山断裂带上类似2008年5月12日Ms8.0汶川大地震的强震复发周期为3000～6000a。     

汶川8级大地震同震破裂的特殊性及构造意义——多条平行断裂同时活动的反序型逆冲地震事件

汶川地震是有仪器记录以来发生的世界上最大的板内逆冲型地震之一。野外调查表明,沿北东走向的龙门山断裂带上,至少有两条逆冲断裂同时参与汶川地震的同震破裂过程,即北川断裂和安县灌县断裂（彭灌断裂）。倾向北西的高角度北川逆冲断裂上的地表破裂长度大于200 km,可能达225 km。运动方式在南部表现为以北西盘抬升的逆冲为主,往北东转为逆冲右旋走滑,走滑分量与垂向陡坎高度相当,陡坎高度最大值约为11 m。在彭灌断裂上,地表破裂表现为北西盘抬升的近纯逆冲性质的破裂,破裂长度达70 km,陡坎最高达3~3.5 m。汶川地震是世界上第一次明确记录到多条平行断裂参与同震破裂的逆冲型地震,而且因发震断层是龙门山断裂带内部的高角度逆冲断裂,而非断裂带前锋的低角度逆冲断裂,所以汶川地震属于反序型逆冲断裂活动。这与1999年我国台湾7.5级集集地震和2005年克什米尔7.6级地震类似,说明反序型逆冲地震具有普遍性。汶川地震这一震级大、破裂长的逆冲地震事件是对目前流行的青藏高原下地壳流动的变形假说提出的严峻挑战,同时也表明加强青藏高原东缘南北地震带上其他滑动速率较低但同样具有发生大地震可能性的活动断裂的滑动速率和古地震定量研究的紧迫性,因为这一地区人口密度与东部相当,但发生强震的频率更高。     

龙门山活动断裂带运动学特征及其构造意义

2008年青藏高原东缘龙门山地区发生的MS8.0级地震,致使龙门山断裂带的后山断裂、中央断裂和前山断裂也发生了构造活动,产生了不同规模的同震地表破裂带,同时在活动断裂面上保留了最新擦痕和正反阶步。根据断裂面阶步及最新擦痕测量分析,后山断裂的耿达—草坡段为逆冲断层,汶川—茂县段为逆-走滑断层,由擦痕反演的最大主压应力为近水平的NW—NWW向;平武—青川段为走滑-逆断层,由擦痕反演的最大主压应力为近水平的SWW—W向。中央断裂的映秀—小鱼洞段为逆冲断层,小鱼洞北—北川段为逆-走滑断层,由擦痕反演的最大主压应力为近水平的NW—NWW向;北川县北—南坝段为走滑-逆断层,由擦痕反演的最大主压应力为近水平的SWW—W向。前山断裂的都江堰—蓥华段为逆冲断裂,蓥华—西坪段为逆-走滑断层,由擦痕反演的最大主压应力均为近水平的NW—NWW向。对比分析表明,擦痕反演最大主压应力方向变化过程与地震资料反演最大主压应力方向变化过程相吻合。     

九寨沟7.0级地震的地震断裂及震源破裂的构造动力学机理研究

本文针对九寨沟7.0级地震的发震构造及震源破裂的构造动力学问题,从地质调查、测试与震源构造动力学理论分析相结合的角度阐明:此次地震发生在处于高法向应力左旋剪切受力状态的岷山隆起带北端与西秦岭地槽褶皱带之南缘文县-玛沁断裂相交汇部位;沿"九寨天堂"-震中-五花海以及上四寨村-中查-比芒一线发育的两条具有构造破裂特征的NW向地裂缝带,是"隐伏状"地震断裂错动造成的地表同震破裂,前者是本次地震的控震构造,后者是NW向断层的次级同震复活及扩展;此次地震的震源断层错动过程受NW331°走向的陡倾角（∠87°）断层节面控制的走滑型剪切破裂,断裂两端的剪切破裂表现出持续扩展趋势;震源构造动力学过程实质上是地壳深部沿NW方向左旋剪断"凸出体";地震断裂带两端破裂扩展的持续发展,将导致地壳"凸出体"逐步剪断贯通。     

滇西南2014年景谷中-强震群的地质构造成因——茶房-普文断裂带贯通过程的构造响应

2014年10—12月期间,云南景谷接连发生了Ms6.6、Ms5.8、Ms5.9三次中-强地震。为确定地震的地质构造成因,在地表调查的基础上,综合该区的地质构造情况、烈度与余震分布、震源机制解等资料,确定此次震群活动的宏观震中位于永平盆地东南侧山地,发震断层为地质与地貌表现不显著的NW向右旋走滑断层。此次震群活动及余震迁移过程指示,由于断层斜接部位岩桥的临时阻碍,Ms6.6地震破裂在向南东扩展过程中发生短暂停滞,突破障碍后进一步引发了Ms5.8和Ms5.9地震,这符合震源破裂沿NW向发震断裂分段破裂的行为。区域活动断裂的遥感解译结果发现,发震断层位置恰好处于NW向右旋走滑的茶房断裂与普文断裂之间,区域上属于该断裂带的不连贯部位,指示此次中-强震群活动应该是茶房-普文断裂带贯通过程的构造活动表现。结合思茅地块的历史地震资料发现,思茅地块地震活动多以小于等于6.8级为主,发震构造多为NW向断裂。指示在现今构造应力场作用下,该区NW向断裂的活动性相对NE向断裂更加显著,属于该区主要控震构造,应在今后的地震地质工作中给予更多关注。     

龙门山小鱼洞断裂在汶川地震中的地表破裂及地质意义

在龙门山中段小鱼洞地区映秀－北川断裂和彭县－灌县断裂发生了同震位移,同时在该地区新出现了一条北西向的同震破裂带——小鱼洞断裂的破裂带,并分割了两条近于平行的北东向逆冲－走滑型的主断裂。汶川特大地震发生后重点对小鱼洞断裂的地表破裂开展了详细的野外地质填图,利用全站仪和GPS对地表破裂进行了精确的测量。初步调查的结果表明,小鱼洞断裂位于映秀－北川断裂与彭县－灌县断裂之间,走向近于北西向,延伸约15km,以脆性破裂为特征,穿过小鱼洞大桥,并切割了多种类型的地貌单元,使道路发生拱曲、破坏和桥梁垮塌或移位。单个破裂长度在几米到300m不等,其南西盘为上升盘,北东盘为下降盘,平均垂直位错为1.0m,平均水平位错为2.3m,垂直与水平位错量之比1 ∶1～1 ∶2,显示为逆冲分量小于或等于左旋走滑分量,并以左旋走滑作用为主。同时,研究表明小鱼洞断裂属于映秀－北川断裂与彭县－灌县断裂之间的捩断层,其主要特征包括： 1)是在汶川地震中由于龙门山逆冲体之间的差异逆冲运动过程中而形成的断裂; 2)其走向近于北西向,垂直于龙门山北东向的主干断裂,而平行于逆冲体的逆冲运动方向; 3)具有高角度断面的断层,以左旋走滑作用为主。     

东濮凹陷北部沙河街组三段中亚段沉积环境分析

东濮凹陷北部沙三中亚段广泛发育盐岩和烃源岩,这两个看似不能共存的物质却在这里互层共生。该时期研究区沉积特征为多盐韵律与多层烃源岩互层共生、连续沉积,单个盐韵律厚度从几米到十几米,烃源岩有机质丰度高、类型好。平面上,两者在湖盆沉积沉降中心共生;垂向上,高有机质丰度、好干酪根类型与高盐度地层具有较好的对应关系。因而成为恢复古气候和古环境的重要研究对象。通过岩石学、古生物学以及Sr/Ba、B/Ga、(V+Ni+Mn)、Fe/Mn、Sr/Cu、Mg/Ca、V/(V+Ni)、稀土元素含量和氯同位素等方法对凹陷北部沙三中亚段的沉积环境进行研究。结果表明,凹陷北部沙三中亚段为深水沉积的还原环境,古盐度较高,达到半咸水-咸水沉积;微量元素和孢粉化石特征表明研究区沙三中亚段为温暖潮湿的环境。     

The Importance of the Precipitation and the Susceptibility of the Slopes for the Triggering of Landslides Along the Roads

In order to characterise the influence of the heavyrains on the observed landslides during the 1996–1997hydrological cycle, rainfall records for the last 100years are analysed from 104 stations in easternAndalusia. Regarding the amounts of rain recordedbetween October 1996 and March 1997 in the 104stations studied, 31 presented new all-time records;15 presented values that were 80–100% of thepre-1995 record; 49 stations, 80–50%; and 9stations, < 50%. A map has been devised of thesusceptibility of the materials through which thesouth-eastern Andalusian road network crosses,together with an inventory of the damage caused byinstability phenomena on banks and cuttings of theroad network during the winter of 1996–1997. Therelationships between the rainfall during the studyperiod, the damage caused to the road network and thesusceptibility of the materials affected are analysed.The results indicate that there is a clearcorrespondence between the rainfall recorded and thesusceptibility of the materials with the inventorieddamage. It is concluded that the widespread seriousdamage caused in early 1997 to the roads andsurrounding areas in the Alpujarra region and thecoast of the Province of Granada was mainly caused bythe extraordinarily heavy rains. However, considerablyless damage was observed where the susceptibility ofthe terrain is low, thus highlighting the extremeusefulness of terrain-susceptibility maps for riskprevention and territorial planning.     

郯庐断裂南段研究进展与断裂性质讨论

据1：5万区域地质调查和专题研究资料，就郯庐断裂带是否南延与消失的原因，其与大别—苏鲁造山带交截形成的假位错效应，以及与中新生代沉积盆地形成演化的关系等作了新的阐述。在此基础上，讨论了郯庐断裂带是否为巨大的左行平移断层或转换断层。认为郯庐断裂带可能是在“古郯庐带”的基础上于早侏罗世重新活动、白垩纪强烈活动的地堑型枢纽断裂带。     

Unity of the national and the international in the socio-cultural development of the peoples of the USSR

International unity is becoming ever stronger in this country owing to an increasing similarity in the development of the cultural environment. This comprises the provision of all the country's republics with a sufficient number of schools, theatres, and other institutions and cultural information media in accordance with the needs of the population. An important part is played by the rise in ‘the general educational level, as well as the level of professional qualifications and skills. Among all the Soviet nations and nationalities, this rise being more rapid among formerly backward peoples. Prominent among the factors of internationalization is the progressive development of the nationalities’ cultural resources, while professional culture is being increasingly brought within the reach of the masses.The implementation of the nationalities policy promotes the all-round development of all Soviet nations and nationalities, their drawing together, the upsurge of the individual capabilities of every Soviet citizen.     

某高速公路下伏煤矿采空区稳定性分析

在论述某高速公路下伏砦脖煤矿采空区地质、采矿和工程地质特征的基础上, 进行了稳定性数值模拟分析, 定性与定量地分析与评价了该煤矿采空区的地表变形特征及稳定性。研究结果表明: 该煤矿采空区的变形尚未完成, 对拟建的高速公路将产生很大的危害, 必须采取相应的工程治理措施。      

塘口水电站坝基岩体透水性和渗漏问题分析

塘口水电站大坝基础座落在断层和裂隙较发育的龟裂纹灰岩上,岩体完整性差、透水性强,多年运行后,大坝灌浆廊道和排水廊道出现多处集中性漏水,为确保大坝安全和电站正常发电,根据渗漏性质和成因,采用对灌浆廊道补充帷幕灌浆,对排水廊道进行固结+帷幕+回填灌浆。通过灌浆处理后,效果良好,表明灌浆工程有效的将导致坝基渗漏的上下游的裂隙通道封闭,并顺利的经受了随后的汛期洪水考验,大坝安全得到保障。     

Report of the restudy of the defined global stratotype of the base of the Silurian System

The Global Stratotype Section and Point （GSSP） for the base of the Silurian System was defined in 1985. Since that time, a number of researchers have suggested that this section has serious deficiencies for use as a GSSP. As a result, in 2000, the Subcommission on Silurian Stratigraphy （SSS） proposed undertaking a formal restu@ of this GSSP, which was subsequently approved by the International Commission of Stratigraphy （ICS）. The result of this restudy was the formal proposal that the current GSSP, at 1.6 m above the base of the Birkhill Shale, at Dob＇s Linn, Scotland, should be maintained as the same locality and stratigraphic level, but the bios- tratigraphical definition of the boundary should be revised. The previously defined, basal Silurian grapto- lite zone, the Parakidograptus acuminatus Zone, should be subdivided into a lower Akidograptus ascensus Zone and a higher E acuminatus Zone. The base of the A. ascensus Zone, marked by the first appearance of A. ascensus, should be regarded as the biostratigraphic mark for the base of the Silurian. This proposal has now been formally approved by the SSS and ICS, and ratified by International Union of Geological Sciences. This is the first GSSP to undergo formal restudy and redefini- tion, and the proposal also included a recommended procedure for restudy of GSSPs.     

Calculation of the Inverse of the Covariance

In reservoir characterization, the covariance is often used to describe the spatial correlation and variation in rock properties or the uncertainty in rock properties. The inverse of the covariance, on the other hand, is seldom discussed in geostatistics. In this paper, I show that the inverse is required for simulation and estimation of Gaussian random fields, and that it can be identified with the differential operator in regularized inverse theory. Unfortunately, because the covariance matrix for parameters in reservoir models can be extremely large, calculation of the inverse can be a problem. In this paper, I discuss four methods of calculating the inverse of the covariance, two of which are analytical, and two of which are purely numerical. By taking advantage of the assumed stationarity of the covariance, none of the methods require inversion of the full covariance matrix.     

Deviation of the major axis of the inertia ellipsoid of the Moon from the direction toward the Earth

It is known from observations that the center of mass of the Moon does not coincide with the geometric center of its figure, and the line connecting these two centers is not aligned with the direction toward the center of the Earth, instead deviating toward the Southeast. This stationary deviation of the axis of the inertia ellipsoid of the Moon to the South of the direction toward the Earth is analyzed. A system of five linear differential equations describing the physical libration of the Moon in latitude is considered, and these equations are derived using a new vector method taking into account perturbations from the Earth and partly from the Sun. The characteristic equation of this system is obtained, and all five oscillation frequencies are found. Special attention is paid to the fifth (zero) frequency, for which the solution of the latitude libration equations are stationary and represents a previously unknown additional motion of the rotational axis of theMoon in a cone with a small opening angle. In contrast to the astronomical precession of the Earth, the rotation of the angular-velocity vector is in the positive direction (counter-clockwise), with the period T ₃ = 27.32 days. On this basis, this phenomenon has been named “quasi-precession.” This quasi-precession leads to a stationary inclination of the major axis of the inertia ellipsoid of theMoon to the South (for an observer on Earth), making it possible to explain one component of the observed deviation of the center of mass of the Moon from the direction toward the Earth. The opening angle of the quasiprecession cone is approximately 0.834″.     

Artemia in the Salt Lakes of Russia:the Productivity of Populations,the Reserves of the Cysts and the Fisheries

正Artemia cysts are an extremely important component of aquaculture diets.It is well established that the cultivation of fish and shellfish derive substantial health and growth advantages when Artemia are included in the diets of the