首都圈地震活动构造成因的小震精定位分析

应用双差地震定位法对首都圈及其邻区1980～2004年发生的地震进行重新定位，进行首都圈的地震构造成因分析表明：重定位的地震表现为与区域构造更为密切的“井”字形活动分布，地震震源分布证实了人工地震勘探所推断的深大断裂的存在；首都圈地区的地震多发生于地壳的中、上部，可能存在局域构造块体运动变形和深部构造动力作用的二种不同地震构造成因；地震活动图像表明中强震易发生在上下地壳相交的脆－韧性转换带中，并揭示了首都圈地区潜在的地震空区和陡倾角的隐伏断层.     

安宁河—则木河断裂带及周边地区断层交会部位的应力分布特征

根据构造活动特性对安宁河—则木河断裂带及周边地区进行分段,利用多地震的断层面解和中小地震的震源参数结果分析不同断层交会区的局部应力场和地震活动特征。结果表明:研究区北段的断裂呈"入"字形交会,具备应力高度集中的局部条件,地震活动频度高、震级偏大,震源应力降普遍较高;中段上,安宁河空区内部的断裂呈"钝角"形交会,地震活动稀疏,震源应力降偏低,而空区东侧的断裂呈"Y"字形交会,中小地震比较活跃,震源应力降值总体居中;在研究区南段,多条断裂呈"Y"字形交会,可能不具备应力高度集中的构造条件,虽然地震活动频度高、震级偏大,但震源应力降值总体居中。研究区地震活动和应力分布的分段差异,与断裂间的相互作用形式有关,交叉断层间的变形不协调对局部应力场和地震危险性有较大影响。     

由跨断层形变测量反映的华北地块近期断裂活动特征

通过对华北地块不同构造部位、不同地震活动时段的跨断层测量资料研究表明，华北地块对于NE走向断裂作用为主的构造单元(包括地块和边界带)的强震活跃时段的断层运动速率明显小于强震不活跃时段；对于NW走向断裂作用为主的构造单元，其强震活跃时段的断层运动速率明显大于强震不活跃时段；对于NE、NW走向断裂共同作用的构造单元，断层运动速率变化特征类似于NW走向断裂作用为主的构造单元。结果还表明，华北地块现今强震活动主要受NW走向断裂的控制。     

鲜水河断裂带南东段康定—色拉哈断裂的浅层地球物理勘探

活动断层不仅是产生地震的根源,而且地震时其断层线两侧的建筑物破坏最为严重。因此准确探测出活动断层的位置和分布范围,并采取有效的工程避让措施,可大大降低地震灾害和经济损失。康定—色拉哈断裂作为鲜水河断裂南东段的主干断裂,具备发生强震的地震地质构造条件,因此该断裂所穿越的几个城镇的地震危险性不容忽视。针对康定新城探测场区存在交通条件不便、场地工作面狭窄等问题,在浅层地震反射波法探测工作中采取小道间距、小偏移距、多道短排列接收和共反射点多次覆盖观测的工作方式获取地震反射时间剖面,浅层地震探测结果辅以高密度电阻率成像断面,并结合地表地震地质调查结果,共同揭示康定—色拉哈断裂在康定新城北侧的展布位置、产状规模和近地表构造形态。研究结果发现康定—色拉哈断裂在康定新城北东侧呈左旋右界羽列状展布,经过两岔口村折多河Ⅰ级阶地处该断裂隐伏段近地表倾角约40°～50°,其破碎带及其影响带宽度约110m,随着地形的升高,破碎带的视宽度进一步增加至200m左右,并沿断层垭口向木格措方向延伸展布。浅层地球物理探测成果为判定康定—色拉哈断裂近地表构造活动提供了可靠的地震学证据,也为康定新城的地震危险性评价和制定抗震防灾规划提供了可靠的基础资料。     

华北活动地块区南缘阜南-霍邱地区地壳活动习性初探

阜南-霍邱地区地处华北和华南活动地块区边缘构造带，通过对其进行地震地质调查和综合分析研究，发现晚更新世以来该区存在强度较弱的构造变形现象，即：小震沿着主要断裂呈线性条带状分布；研究区南部及断裂近侧的上更新统中发育共轭剪节理；1970年代，研究区固始、霍邱和阜南等地陆续发生过长度不一、宽窄不等、方向不同的地裂缝，展布与肥中断裂或王老人集断裂近乎一致。本文认为，研究区局部小震丛集、上更新统中赋存共轭剪节理、裂面充填物显微揉皱变形和现代地裂缝的生成等现象，反映出地壳能量被缓慢释放和相应断裂发生微弱活动；研究区曾发生过一次破坏性地震(江口集Ms43/4地震)。综上所述，研究区地壳晚第四纪以来具有微弱活动性，且主要表现为蠕滑活动方式。     

豫西嵩县盆地周边地区地震空区地质环境初探

通过时豫西嵩县中～新生代断陷盆地构造类型、断裂发育及其活动程度的初步分析，认为该盆地及其邻区具有断裂发育规模小、新构造活动程度低、盆内无次级断裂及其所围限的地堑和地垒断块构造发育等特征，从而形成了被深断裂割开的地震空区     

赣江断裂第四纪活动性初步研究

赣江断裂带是江西省境内一条重要的区域性大断裂。断裂涉及九江、南昌和吉安等江西重要经济区,因此充分研究该断裂活动性对认识断裂沿线分布的历史地震的发震构造及规划断裂沿线城市的经济建设有科学意义。大致以丰城为界,赣江断裂北段(丰城—湖口段)和南段(吉水—丰城段)走向有明显的变化,北段走向NNE,南段走向NE,断层南北两段地震活动性略有不同,北段沿线记录地震多于南段。针对断层隐伏区采用了浅层地震勘探法和跨断层综合地质剖面法相结合的研究方法、对断层出露区采用断层剖面出露点观察调查法。综合研究结果表明:赣江断裂南、北两段的最新活动性时代一致,均为中更新世。     

台南盆地的地震构造ht

由于发生1906,1941,1946,1994和1999年的破坏性地震，对台南盆地的地震构造有了更全面的了解，并对台湾西南部的活动右旋走滑的义竹断裂有了新的看法. 曾熟知的梅山断裂和新化断裂不是独立的地震断裂，它们均属于义竹断裂的分段. 1994年9月16日，震中在台湾海峡、台南盆地边缘的地震，断层面接近东西向.此地震为台南盆地沉降历史过程中，右旋走滑断裂的活动剪裂所导致. 从1941年和1999年地震的主震和微震记录中发现，这些菱形分布的地震图像，象征走滑断裂双轨构造中的压缩区. 基于上述研究及其它资料表明义竹断裂是台湾西南部重要的构造活动带，并具有引发地震的可能性.      

依兰-伊通断裂方正-萝北段氢气特征研究

为研究断裂与断层氢气间的关系，围绕依兰-伊通断裂方正-萝北段开展断层氢气浓度流动观测工作，得到该段断裂氢气浓度变化特征。结果表明:在时间尺度上，氢气浓度存在年变规律特征，主要受温度、湿度和微生物活动的影响，一年中夏季氢气浓度最高，春秋季最低；在空间尺度上，依兰-伊通断裂北段呈南低北高的分段性特征，氢气浓度高值地区对应地震活动较强的地区，低值地区对应地震活动较弱的地区，这与当前地震活动特征相符，说明断层氢气浓度与当前地震构造活动具有较好的耦合关系。     

安徽西南宿松-枞阳断裂中段活动性的综合评价

安徽西南的宿松－枞阳断裂有历史记载以来曾发生多次中、小地震。综合近年来在该地区进行的一些重大工程场地地震安全性评价工作积累的资料，利用宏观、微观构造相结合的分析方法，配合断层物质测年等手段，对该断裂中段进行了较系统的研究，说明了近代中、小地震沿断裂发生的地质背景，并对断裂未来地震活动水平进行了初步预测，为弱震地区断裂活动习性综合评价提供了一个实例     

琼中地震台重力仪记录同震响应特征分析

2013年2月6-8日圣克鲁斯群岛发生6次强震,琼中地震台的重力仪记录都有同震响应出现。本文从重力仪记录的面波的延迟时间、最大变形幅度、同震持续时间3个方面研究了6次强震的同震响应特征。     

Contribution to the knowledge of the magmatic evolution by the study of the variation of the coefficient of viscosity

The determination of the coefficient of viscosity of eruptive products gives useful elements to the knowledge of possible variations of composition and physical conditions of the magmas.     

On the Mechanism of the Secular Tidal Acceleration of the Solid Inner Core and the Viscosity of the Liquid Core

As is known, the secular deceleration of the Earth's diurnal rotation is explained mainly by the tidal friction in the ocean. Below we consider this mechanism in some detail, taking into account also elastic deformations of the mantle under the action of ocean loading and the interaction between the tide-generating body, ocean tidal wave, liquid outer core, and solid inner core. It is shown that elastic displacements of the core-mantle boundary under the action of ocean loading are of about the same amplitude and phase as the elastic loading displacements of the Earth's outer surface. As a result, side by side with the mechanism of secular deceleration of diurnal rotation of the mantle, there are also (1) the opposite mechanism of secular acceleration of diurnal rotation of the outer liquid core and of the solid inner core and (2) the mechanism of excitation of differential rotation in the liquid core. Taking these effects into account, we compare theoretical and modern observed data on the eastward drift of the solid inner core. It is shown that the best agreement may be obtained if the turbulent viscosity of the liquid core is about 2 × 10 ³ Poise     

Comparison Between the Nutations of the Planet Mars and the Nutations of the Earth

The nutations of the planets Mars andEarth are investigated and compared. Alarge number of interior structureparameters are involved in the nutationcomputations. The comparison between the observations and the computationsprovides several constraints on these parmeters andtherefore allows a better understanding of the physics of the interior of theplanet. For the Earth, the high precision of the observations of the nutationshas led to a very good determination of interior properties of the planet. ForMars, observations of nutations are not yet available, and we review how theamplitude of the Martian nutations depends on the hypotheses consideredfor its interior. Although Mars is very similar to the Earth, its interior is not well known;for example, we don't knowif its core is liquid or solid. Only if the core is liquid,the Free Core Nutation (FCN) normal mode exists and can alter the nutationswhich are close to the resonance. From the observed geoids, it is known thatboth planets are not in hydrostatic equilibrium. The departure is larger forMars than for the Earth, and consequently, the implication of considering a convective mantle instead of a mantle in hydrostatic equilibrium described byClairaut's equation for the initial equilibrium state of the planet is largeron the Martian nutations than on the Earth nutations. The consequences of theuncertainty in the core dimensions are also examined and shown to be of a veryhigh influence for Mars if the core is liquid, due to the potential changes inthe FCN resonance. The influence of the presence of an inner core, which isknown to exist for the Earth, could be more important for Mars than for theEarth if the inner core is large. Due to the presence of Tharsis on Mars, thetriaxiality of this planet has, additionally, larger effects than on Earth.     

Pictorial Series of the Manifestations of the Dynamics of the Earth

Studia Geophysica et Geodaetica -     

动水压力对深水桥墩地震响应影响的研究综述

地震激励下处于深水中的桥墩和周围水体的相互作用将对桥梁结构的动力响应产生较大影响。首先对地震作用下水-桥墩的相互作用理论做了概括,给出了动水压力对桥墩的作用效应及各自的适用范围;对主要的三种考虑流固耦合效应的分析方法做了对比,探讨了地震作用下影响水-结构相互作用的主要因素,并对今后的研究提出了建议。     

Evolution of the Source of the Active Region of the Sun

Geomagnetism and Aeronomy - The magnetic evolution of the active region of the Sun at the level of the photosphere has been studied. Magnetic synoptic maps of the 2007 Kitt Peak Observatory were...     

Magnetic stratigraphy of the Ordovician in the lower reach of the Kotuy River: the age of the Bysy-Yuryakh stratum and the rate of geomagnetic reversals on the eve of the superchron

Until recently, the existing data prevented the geophysicists from accurately dating the Bysy-Yuryakh stratum, which outcrops in the middle reach of the Kotuy River, constraining the time of its formation to a wide interval from the end of the Late Cambrian to the beginning of the Silurian. The obtained paleomagnetic data unambiguously correlate the Bysy-Yuryakh stratum to the Nyaian regional stage and constrain its formation, at least a considerable part of it, by the Tremadocian. This result perfectly agrees with the data on the Bysy-Yuryakh conodonts studied in this work and yields a spectacular example of the successful application of paleomagnetic studies in solving important tasks of stratigraphy and, correspondingly, petroleum geology. Within the Bysy-Yuryakh stratum, we revealed a large normal-polarity interval corresponding to the long (>1 Ma) period when the geomagnetic reversals were absent. This result, in combination with the data for the Tremadocian and Middle–Upper Cambrian sequences of the other regions, indicates that (1) the rate of occurrence of the geomagnetic reversals on the eve of the Ordovician Moyero superchron of reversed polarity was at most one reversal per Ma; (2) the superchron does not switch on instantaneously but is preceded by a certain gradual change in the operation conditions of the dynamo mechanism which, inter alia, manifests itself by the reduction of the frequency of geomagnetic reversals with the approach of the superchron. This finding supports the views according to which a process preparing the establishment of the superchrons takes place at the core–mantle boundary.     

The effect of the pollution of the ground layer of the atmosphere on the albedo

Summary A simple model is proposed suitable for studying the effect of the ground layer of the atmosphere, polluted by aerosol, on the albedo. This model is founded on solving the equation of transfer of radiative energy. The numerical results are discussed, particular attention being paid to the analysis of errors due to neglecting the multiple reflection of solar radiation on the aerosol particles. A method which would also include the multiple reflection is proposed, and the conditions under which the presence of the aerosol is responsible for an increase or decrease of the solar radiation balance on the Earth's surface, are analysed.