中国数字地震台网的建设与发展

ldquo;十五rdquo;（2001——2005年）期间,中国地震观测系统得到了迅速的发展,中国地震局完成了ldquo;中国数字地震观测网络rdquo;项目建设,将所有模拟地震观测系统全部进行了数字化改造,并新建了一些数字化地震台站,标志着中国的地震观测已进入数字时代. 本文介绍了新一代国家数字地震台网、区域数字地震台网、火山数字地震台网和流动数字地震台网的规模、布局原则和主要功能.      

Construction and development of China digital seismological observation network

The seismological observation system in China has experienced rapid development over the Tenth Five-year Plan period. China Earthquake Administration (CEA) has completed the establishment of China digital seismological observation network. CEA has accomplished analog-to-digital conversion of the existing seismological observation systems and set up a number of new digital seismic stations. This indicates full digitization of seismological ob-servation in China. This paper presents an overview of the scale,layout principle and major functions of the up-dated national digital seismograph network,regional digital seismograph network,and digital seismograph net-work for volcano monitoring and mobile digital seismograph networks in China.     

A new technique for moment tensor inversion with applications to the 2008 Wen-chuan M_s8.0 earthquake sequence

A MS8.0 earthquake occurred in Wenchuan County, Sichuan Province, China, on May 12, 2008, and subsequently, numerous aftershocks followed. We obtained the moment tensor solutions and source time functions (STFs) for the Wenchuan earthquake and its seven larger aftershocks (MS5.0~6.0) by a new technique of moment tensor inversion using the broadband and long-period seismic waveform data from the Global Seismic Network (GSN). Firstly, the theoretical background and technical flow of the new technique was brie...     

Crustal seismic anisotropy in southeastern Capital area, China

Shear-wave splitting parameters of 24 stations in southeastern Capital area of North China (38.5°N~39.85°N, 115.5°E ~118.5°E) are obtained with systematic analysis method of shear-wave splitting (SAM) based on the data recorded by Capital Area Seismograph Network (CASN) from 2002 to 2005. The results show that the average polarization of fast shear-wave in southeastern Capital area is consistent with regional maximum horizontal prin- cipal compressive stress in the area, and is also consistent with maximum horizontal principal compressive strain from GPS in North China. The average shear-wave splitting in southeastern Capital area (in basin) is different from that in northwestern Capital area where uplifts and basin exist, which means that tectonics can be related to shear-wave splitting results. Research also shows that the distribution of faults around stations can obviously affect the shear-wave splitting results, and complicated distribution of faults can result in much more scatter of shear-wave splitting. Moreover, in the north and south of the studied area (southeastern Capital area), the polariza- tions of fast shear-wave are not very consistent, which may be related to differences in tectonic and stress for the two areas.     

非对称地震矩张量时间域反演:理论与方法

本文在对称地震矩张量反演的基础上,进一步研究了非对称地震矩张量时间域反演的理论与方法,结果表明:非对称地震矩张量反演与对称地震矩张量反演类似,只需将对称地震矩张量反演方法略加改动,即增加3个待解参数,便可实现非对称地震矩张量反演.为了判断非对称地震矩张量反演相对于对称地震矩张量反演是否存在过度拟合,运用了AIC准则 (赤池信息准则).为了定量地描述地震矩张量之间的差异,引入了地震矩张量的矢量表示法.通过分析格林函数与地震矩张量各分量之间的关系,得出:在非对称地震矩张量反演时,若仅用垂直向地动位移数据,将无法区分M_xy与M_yx这两个分量, 需要同时运用垂直向与水平向地动位移数据进行联合反演才能区分M_xy与M_yx; 若采用不同的速度结构模型或不同的格林函数计算方法,则需重新评估地震矩张量各分量的分辨度问题.为检验非对称地震矩张量反演方法的可行性, 利用合成地震图进行了一系列数值试验.数值试验结果表明,在非对称地震矩张量反演中,有必要引入S波进行P波与S波联合反演以提高反演的准确性和判定断层面的能力.      

《纪念汶川大地震十周年》专辑前言

正2008年5月12日四川汶川M_W7.9(M_S8.0)地震发生至今,已经10年。这次地震造成了69 227人死亡、374 643人受伤,经济损失高达8 452.15亿元。汶川地震的发生,以及全国、全球范围破坏性地震的不时发生,一次又一次地提醒人们:虽然地震科学技术在近半个世纪以来已有长足的发展,但地震科学家对于地震发生规律的认识水平目前仍然是很低的,距离社会的需求相去甚远。"亡羊补牢"。地震科学家应正视现实、深刻反思、系统分析总结这次     

共轭地震与地壳介质内摩擦系数的测定

安德逊理论表明地震的共轭破裂现象可以用库仑准则解释,断层面夹角与地下岩石内摩擦系数之间存在简单的定量关系。基于本文提出的通过共轭地震计算介质内摩擦系数的方法,对国内外19个具有X形或不完整的X形（L形）共轭破裂特征的地震进行系统性分析,与震源机制、区域应力轴方向等资料进行对比,确定共轭断层面,进而确定共轭面夹角并计算岩石的内摩擦系数。研究结果进一步证实了天然地震的共轭破裂与实验室岩石破裂具有较好的一致性,给出了库仑准则与安德逊理论在大尺度下也成立的证据,表明通过共轭角确定地下介质的内摩擦系数是对地下介质特性认知的有益补充。     

USGS/ASL对观测地震学的贡献

综述了美国地质调查局阿尔伯克基地震实验室(USGS/ASL)自1961年以来对部署全球地震台网和发展观测地震学做出的贡献。     

跨世纪的中国地球科学

１发展之中的地球科学地球科学是历史最为悠久的科学分支之一,也是最早引入中国的现代科学之一。作为一门已有数百年历史的科学分支,地球科学在今天的发展状况,是每一个关注地球科学进展的人都十分感兴趣的问题。从某种意义上说,对这个问题的认识,决定着我们如何把握...     

Tunnel effect of fractal fault and transient S-wave velocity rupture (TSVR) of in-plane shear fault

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