伊通－舒兰断裂分段及地震危险性探讨

本文用地震活动性参数等地震学方法和用时间域小地震地震图测量震源物理参数及介质Ｑ值等震源参数方法，对伊通－舒兰断裂进行分段及地震危险性探讨。初步研究结果表明该断裂乌拉街－舒兰段（北段）、伊通－双阳段（南段）存在明显差异，北段介质强度大，易积累能量而发生较大地震。     

昌平南口山前断裂断层分段的地震学特征

利用北京昌平南口地区的地震活动性、震源参数与介质特性等对南口山前断裂进行断层分段，结果表明该断层各段的地震学特征差异明显，与地质学手段所得到的部分结果是一致的     

体波单震相测定震源机制的方法

本文提出了体波单震相测定震源机制的方法。按理论地震图公式，直达Ｐ波和Ｓ波地表垂直分量位移由地震矩，震源幅射和介质响应之积组成。我们将其变换成地震矩，假定断裂参数的单位地震矩单震相理论子波和待守断裂参数与假定断裂参数辐射函数之商的乘积，在各台理论与实际体波单震相最大振幅的最小二乘法中求解出震源参数，利用ＣＤＳＮ数字台网资料，我们分析了青海共和地震的震源机制。结果表明，１９９０年４月２６日Ｍｓ＝６．７     

红河断裂深部震源环境介质力学性质分析

应用震源波谱分析对红河断裂带深部震源环境介质力学性质和地质资料的研究,证明在弥渡以南的红河断裂深部存在有利于蠕滑活动的环境介质条件,从而对红河断裂地震活动的不均匀性提出了新的解释     

2013年吉林前郭5.8级震群精定位及发震构造分析

利用吉林区域数字地震台网和流动台网的观测数据,采用Hypo DD方法精确定位了2013年10月31日~12月10日发生在吉林前郭地区343次地震事件的震源位置。重新定位结果显示,地震序列优势分布方向为NW向,平行于查干泡-道字井断裂北支。重新定位后的震源分布更趋集中在断裂带附近,且深度多集中在6~14km范围内,表明研究区的孕震层主要集中在中上地壳,与该区的地下介质性质关联明显。以同样的方法修正了5.5级和5.8级地震序列的震中位置和震源深度,重定位后2次序列的优势方向、优势深度和破裂长度均存在明显差异。基于震源机制解及震源深度剖面图初步推测此次地震的发震构造应为NNW向的查干泡-道字井断裂。     

秦山核电站厂址地震动加速度时程预测研究

本文研究了建立设计地震震源模型和用理论地震学方法预测基岩场地震震加速度的技术途径，预测了四相设计地震事件在秦山核电站厂址的加速度时程和反应谱，文中根据对地质和历史地震资料的研究，确定不同性质的设计地震事件，建立设计地震震源和工作区介质的确定性模型，针对未来地震的不可完全预见性，以及对地球介质和震源性质现有认识的局限性，文中发展了确定性和随机性组合的综合分析方法，在用确定的介质模型和设计震源计算地震     

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。     

固体潮水平分量振幅因子异常多维分析研究

介绍了固体潮水平分量振幅因子异常多维分析的设计思想，计算方法及软件系统的功能与特点。该系统的研究为地震分析人员分析地壳介质特性与震源发展的力学过程提供了新的途径。     

尾波干涉原理及其应用研究进展综述

本文首先简述了尾波干涉方法的基本原理, 随后介绍了尾波干涉方法在研究震源位置变化和监测散射体运移状态的相关应用与进展, 最后探讨了利用重复地震、 人工主动源和噪声互相关函数监测地下介质波速变化的尾波干涉方法的优缺点及发展方向. 尾波干涉方法基于尾波的多次散射特性, 能够提取震源位置与介质的细微变化, 其中介质的动态变化可为地震(火山)的孕育、 形成及发展提供研究思路与指导意义.      

井间地震方向性震源模拟方法

为了能够在水平方向上传播更远的距离,井间地震震源辐射能量具有水平方向强的特性,这是井间地震资料大入射角反射波能量强的主要原因.为了研究井间地震震源方向特性对地震信号的影响,本文提出了圆形震源阵列模拟方法.基于声波方程的一阶应力一速度方程的交错网格有限差分算法,进行了均匀各向同性无限介质的直达波和反射波正演数值模拟.数值模拟结果表明,井间方向性震源辐射能量的方向特性影响了地震记录的能量分布,为进一步研究方向性震源的能量补偿提供了理论依据.     

利用PGA快速确定汶川地震破裂特征

快速确定断层破裂特征是烈度速报的一项重要技术,断层破裂特征可为烈度速报提供震源模型,提升烈度速报准确性。通过汶川地震加速度记录,提出一种快速计算震源破裂参数的方法。 假定断层为线源模型,以一定间距将断层离散化为若干子源,以震中为不动点,通过旋转获得所有断层可能的走向,通过每次移动一个子源,获得断层所有可能的破裂方式,将二者结合即可给出断层所有可能的空间分布;计算每种断层空间分布与每个台站的断层距,利用加速度记录峰值和断层距统计回归衰减关系,分析每个衰减关系的拟合残差,残差最小拟合效果最好的衰减关系所对应断层参数,能够对该次地震的地震动场有最合理的解释,也最有可能是实际地震中的断层空间分布。     

发震时深浅构造相互作用导致横向断层致锁的有限元分析

本文利用三维有限元方法，研究和计算了大震发生前、发生时，发生后震源断层面与深部同面立接断层之间的相互作用以及发震后促使深部断层发生错动从而对震源区近场横向活动断层致锁的结果，得到以下结果：（１）临近大震前震源断层面端部调整单元下方的深部断层有较高的剪应力水平，造成震时对震源断层面发生底辟作用的条件，即调整单元区对应的深部断层单元首次满足破裂条件并发生破裂。（２）震源端部的调整单元和具有蠕能力的横向     

构造地震的前兆理论——震源孕育的膨胀-蠕动模式

较详细地讨论了构造地震的震源孕育情况;在考虑了动摩擦效应后,进一步对震源孕育过程和各种物理量的变化规律进行了分析和计算,提出了震源孕育的膨张一蠕动模式.该模式将孕震过程划分为:弹性变形、非弹性变形（膨胀）、前兆蠕动（断层面局部破裂）、加速蠕动（短期和临震）、整体错动（断层面全部破裂）--发震、震后调整等六个阶段.最后讨论了两类不同前兆、蠕裂和崩裂、非弹性变形（膨胀）速度的变化、各种前兆异常的基本形态、短临前兆的物理基础等问题.研究结果表明,膨胀-蠕动模式可能是认识地震前兆现象本质和发展预报技术的一个物理和力学基础.     

地壳中张力区对孕震断层的作用

本文应用裂缝的位错理论及位错在应力场中受力的概念讨论了地壳中水平张力区对孕震断层的作用。从理论上计算了位于径向分布的张力区中孕震断层端部所受力的表达式和方向。指出张力区对孕震断层有类似于象力的作用。在一定配置条件下,它有利于裂缝的传播,并使裂缝在传播过程中拐弯。地壳底部受一定分布的垂直力作用时,会在其周围产生水平张力区。因此,可以通过地形变资料、孕震断层周围的地质情况去寻找张力区的可能存在区域并分析它对孕震断层可能产生的作用。     

用宽频带波形资料研究青海西捷6.8级地震的震源过程

利用中国数字地震台网（ＣＤＳＮ）的宽频带数字化波形资料进一步研究了１９８８年１１月５日青海省西捷ＭＳ６．８级强震的震源过程。通过波形模拟和基于优化遗传算法的全局反演,对该地震的震源参数和破裂特征进行了分析。初步结果表明,此强震是以一次主破裂为特征的事件,与略带逆掩分量的走滑活动断层有关。根据单向破裂对各台站视震源时间函数的影响的分析,认为破裂可能是沿北西走向的断层面由东南向西北传播     

THE SOURCE PARAMETERS AND RUPTURE PROCESS OF THE MW7.0 EARTHQUAKE IN ALASKA,USA ON DECEMBER 1, 2018

A magnitude M_W7.0 earthquake struck north of Anchorage, Alaska, USA on 1 December 2018. This earthquake occurred in the Alaska-Aleutian subduction zone, on a fault within the subducting Pacific slab rather than on the shallower boundary between the Pacific and North American plates. In order to better understand the earthquake source characteristics and slip distribution of source rupture process as well as to explore the effect of tectonic environment on dynamic triggering of earthquake, the faulting geometry, slip distribution, seismic moment, source time function are estimated from broadband waveforms downloaded from IRIS Data Management Center. We use the regional broadband waveforms to infer the source parameters with ISOLA package and the teleseismic body wave recorded by stations of the Global Seismic Network is employed to conduct slip distribution inversion with iterative deconvolution method. The focal mechanism solution indicates that the Alaska earthquake occurred as the result of tensile-type normal faulting, the estimated centroid depth from waveform inversion shows that the earthquake occurred at the depth of 56.5km, and the centroid location is 10km far away in northeast direction relative to the location of initial epicenter. We use the aftershock distribution to constrain the fault-plane strike of a normal fault to set up the finite fault model, the finite fault inversion shows that the earthquake slip distribution is concentrated mainly on a rectangular area with 30km×20km, and the maximum slip is up to 3.6m. In addition, the slip distribution shows an asymmetrical distribution and the range of possible rupture direction, the direction of rupture extends to the northeast direction, which is same as that of aftershock distribution for a period of ten days after the mainshock. It is interesting to note that a seismic gap appears in the southwest of the seismogenic fault, we initially determined that the earthquake was a typical normal fault-type earthquake that occurred in the back-arc extensional environment of the subduction collision zone between the Pacific plate and the North American plate, this earthquake was not related to tectonic movement of faults near the Earth's surface. Due to the influence of high temperature and pressure during the subduction of the Pacific plate toward to the north, the subduction angle of the Pacific plate becomes steep, causing consequently the backward bending deformation, thus forming to a tensile environment at the trailing edge of the collision zone and generating the M_W7.0 earthquake in Alaska.     

Reevaluation of the offset of the Great Wall associated with the ca. M 8.0 Pingluo earthquake of 1739, Yinchuan graben, China

In this study, we reevaluate, based on our investigation, the ground deformation caused around the area of the Great Wall by the ca. M 8 Pingluo earthquake of 1739 along an active fault zone in the Yinchuan graben, on the western margin of the Ordos Block in northern central China. Previous studies have shown that the Great Wall of China was damaged and right-laterally offset by the 1739 M 8 Pingluo earthquake up to ～1.6–2 m, with a 0.1–1.9-m vertical component, at three locations. However, our recent fieldwork and in-situ measurements have shown that the Great Wall was not affected by the ca. M 8 Pingluo earthquake of 1739, as reported previously, but was actually built on preexisting active fault scarps. This study reinterprets the offset of the Great Wall based on these new field observations and attempts to identify the seismogenic source fault that triggered the 1739 Pingluo earthquake. More work is required if we are to better understand the deformation characteristics of the seismogenic source fault and also improve our ongoing assessments of the seismic hazard within the densely populated area of the Yinchuan graben, central China.     

ANALYSIS ON THE CHARACTERISTICS OF DURATION AND PERIOD OF GROUND MOTION OF THE LUSHAN EARTHQUAKE BASED ON THE STATION RECORDS

Based on 60 records from the 20 stations within 100km to the epicenter of Lushan earthquake, the predominant period, period of peak response spectrum, duration of ground motion, and source duration are investigated. By the study, we conclude that within 100km to the epicenter, the scope of predominant period is 0.013~0. 275s in EW, NS and UD direction; the scope of period of peak response spectrum for 5% damping ratio is 0.03~0.65s; the scope of 90% ground motion durations is 5. 1~35. 9s; the scope of averaging source duration is 6.41 (EW), 6.05 (NS) and 5.47s (UD). Furthermore, based on the ground motion duration calculated by 20 stations dada, the predictive curve and equation of ground motion duration is regressed and compared with the recent equation of ground motion duration by Bommer (2009). We find that the ground motion durations of most stations are larger than predictively mean value by Bommer (2009), which means that the source effect of Lushan earthquake is relatively larger. Lastly, by the contour figure of ground motion duration and source duration, we conclude that the directivity character of duration is relatively apparent in NE direction. The relatively larger source duration and ground motion duration in NE direction indicate more energy release in the main shock of Lushan earthquake, which perhaps causes the relatively less aftershocks in this direction. The duration has no hanging wall effect, which perhaps results from the blind-reverse fault structure of Lushan earthquake.     

利用单台数字地震记录反演天祝—古浪5.4级地震矩张量

利用单台３分向数字化记录反演了１９９６年６月１日甘肃天祝－古浪５．４级地震的矩张量,并对所得结果与用Ｐ波被动符合的结果进行了比较。结果表明,二具有很好的一致性。结合谝地震的震源机制和震源区的断层的构造情况,认为该地震是在ＮＥ－ＳＷ的压应力作用下,近ＥＷ向的源原西断层天祝－古浪段左旋破裂错动的结果。由于我们得出的结果只是利用了记录波形的最初几个波形,因此它基本反映了该地震的初始破裂错动情况。     

断裂活动的平行消减作用

依据断裂活动时代，滑动速率，破裂位移，强震复发期和地震释放能量等要素，通过一些典型实例证明，断裂活动的平行消减作用具有普遍意义，讨论了与断裂活动平行消减作用有关几个问题，本的研究成果对确定断裂活动力源，认识断裂和地质活动规律以及地震预报和地震危险性分析重要意义。