使用稀疏宽带台网进行区域及远区域地震定位和震源参数估计：对里奇克雷斯特地震序列的检验

对1995年加利福尼亚里奇克雷斯特地震序列，使用伯克利数字地震台网（BDSN）的宽带，大动态范围仪器记录的数据进行了地震定位和震源参数估计。本文的目的是研究稀疏宽带合网对网外区域的监测能力，它也适合于全面禁止核试验条约（CTBT）监测小震级地震事件的情况，另外，我们还介绍一个震例研究，这是其他区域宽带台网检测能力的代表。为了评估稀疏台网的检测能力，我们把根据BDSN震相测量所估计的地震位置与“直实位置”目录中由南加州地震台网（SCSN）记录数据得出的高质量地震位置做了比较。为了确定不同类型数据对绝对事件定位的重要性，使用了一个自适应网络搜索定位程度，它利用了一个或多个台站的多震相拾取的时间和方位角。我们使用了BDSN台站距离范围在250－500km和500-800km内的稀疏子台网，结果表明：在区域距离范围内，可能得到达到18km以内的绝对事件定位，这是CTBT所要求的，然而，在远区域距离范围内，较低的保噪水平不可能使事件的定位达到CTBT所要求的目标。     

2016年唐山开平ML4.7地震活动性分析

2016年8月至2016年10月唐山余震区小震活动增强,尤其是8月21日至9月22日期间,其中9月10日发生震级最大地震为唐山开平ML4.7地震。为了解中强地震发震特征及地震序列变化,基于模板匹配定位识别技术,利用2016年8月1日至2016年10月31日连续波形进行唐山开平地震前后微震检测和定位。从研究区域内中国地震台网目录中选择283个地震事件作为模板事件,基于连续波形共检测识别出878个地震事件,其数量约为模板事件的3倍,约为中国地震台网目录的1.4倍,检测后的地震目录完备震级由原来的ML0.2提升至ML-0.1。利用双差定位方法对847个地震事件进行重定位,结果显示震中附近小震活动频繁,且在唐山开平地震震中周边分布较集中。分析震群分布特征认为唐山开平地震属于唐山老震区正常地震活动,发震断层为唐山-古冶断裂的可能性较大。     

辽宁台网记录爆破、矿震与地震的识别

从1999年6月辽宁数字遥测地震台网正式采用数字记录与模拟台站资料结合，编报辽宁省地震月报目录和地震观测报告，数字地震观测技术具有宽频带、动态范围大、分辨率高而且便于用电脑处理等优越性，改变了传统的模拟台网在地震图上识别和辨认震相，取而代之利用人机交互实时处理地震系统在计算机上识别和分析震相。每天有许多触发事件显示在屏幕上或存储在计算机里，这其中有相当多的事件不是地震事件，需要人为加以排出。有些事件是典型的、具有显著的震相特征，是便于识别的。而这些事件缺乏典型特征，不易识别，需要用多台记录进行综合分析，才能做出最后的判断。     

上海及邻区微震检测与定位

本文利用基于图像处理器加速的模板匹配定位法(Graphics Processing Unit-based Match&Locate, GPU-M&L)和双差定位法(HypoDD),对上海及邻区13个台站记录的2011年至2020年共10年的连续地震数据资料进行分析.首先从中国地震台网中心提供的146个地震事件目录中挑选了136个地震事件作为模板事件,使用模板匹配定位技术对上海及邻区10年的连续资料进行遗漏地震事件的扫描和检测,共识别出824个地震事件,约为台网中心提供地震目录事件数量的5.5倍.然后对识别出的地震事件通过深度去噪方法(DeepDenoiser)将信号与噪声分离,并对去噪后地震波形的频率和振幅特性分析来进一步确认识别出的地震事件.同时利用基于机器学习的震相拾取技术(PhaseNet),对去噪后的333个地震事件进行了震相拾取.检测后的地震目录完备震级由台网目录的M_c1.0降为M_c0.8.最后利用双差定位法对479个地震事件进行精定位,精定位的结果显示,上海地区整体地震活动性较弱,地震的空间分布相对较为分散,定位后...     

包头地震台网组网技术架构和地震监测能力分析

作为国家地震台网和区域地震台网的重要补充，地市级地震台网可为本地区地震速报、地震预警、城市防灾减灾和活断层科学研究提供基础数据。本研究采用基于NetSeis/IP协议的网络组网技术，将单个测震台站组建成台网，形成由16个子台组成的地市级地震台网。应用专业软件对组网前后地震监测能力进行评估，结果显示，包头主城区及周边部分地区地震监测能力有了明显提升，达到M_L1.0。同时，以包头主城区及周边地区为研究区域，选取包头地震台网运行以来的地震目录进行检验，证实研究区地震监测能力优于M_L 1.0。     

西藏地震台网检测能力与定位能力评估

根据西藏自治区地震台网的记录,对现有台站的检测能力和定位能力进行了评估,再把“十五”计划增加的台站加入西藏地震台网,估算了该区新台网的检测能力和定位能力。     

台网监测能力变化及其对地震活动性研究的影响

地震目录是研究地震活动性的基本资料。然而地震目录的内容不仅反映了地震活动性的真实变化,也混杂了人为因素引起的变化。这些人为因素包括,台网监测能力的增强或减弱,台网测定震级的系统偏差等。本文首先讨论了对地震频度和平均震级进行z检验以研究地震活动性和识别人为变化的方法,继而对京津唐张地区的资料进行z检验。计算结果表明,北京台网的监测能力在1966年和1984年后曾经有过两次提高,这与北京遥测台网网志的报告大体一致。计算结果也反映出当前台网在震级确定上还存在一些系统偏差,文中讨论了这些偏差对客观地研究地震活动性和地震预报的影响,指出了排除人为因素对地震活动性研究的重要意义。     

数字地震记录的爆破识别

前言随着浙江省数字化地震遥测台网的建成和正式运行 ,地震监测能力有了很大的提高。与原来的模拟台网相比较 ,台站数目大大增加 ,布局也更为合理。数字化地震遥测台网的监测能力在大部分地区至少比模拟台网提高了 0 .5级。这是数字化地震遥测台网运行以来 ,记录到许多大小不同的爆破事件和一些小地震的技术依据。虽然 ,浙江省是少震弱震区 ,但恰逢全省基本建设的高潮期 ,各地都有大工程建设 (如高速公路、跨海大桥、港口码头等 ) ,工程爆破数量大为增多。所以 ,台网记录到的地震虽少 ,爆破事件却很多。浙江省是少震弱震区 ,全社会对地震的…     

人工爆破检验区域地震台网地震定位精度

利用广东地震台网记录的2015年6月珠江口海陆联合地震构造探测项目人工爆破资料,采用MSDP地震分析软件提供的3种常用地震定位方法,对6次人工爆破事件进行分析,将定位结果与已知爆破位置进行对比,验证地震定位精度。结果表明,当地震定位数据满足台网分布方位均匀度ΔU≤0.35、次空隙角(S_(gap))≤160°时,广东地区地震震中定位精度优于3 km。     

巴基斯坦地方地震台网的监控能力与可靠性

使用Bungum和Huseby方法对地方地震台网的监控能力和可靠性进行了分析。用震源位置的标准计算机码重新定位地震事件。由频率震级分布导出50％，90％和100％的累积监控能力阀值，对这些阀值23年内记录资料的监控能力水平作了估测。分析表明，在台网内发生的地震事件的台网100％监控能力水平为ML=1.7，从台网内固定实时震源对台网震源解精度作了分析。地震事件在台网内发生时，震中误差低于4km。最后讨论了地方地震台网连续运行期间影响监控能力的因素。     

Seismic Observations and Seismic Hazard Studies in the Philippines

It has taken more than a hundred years for seismic observations in the Philippines to evolve to a modern observation system.The responsibility of seismic observations was likewise transfeered from one agency to another during this same period of time.At present,the mandate of conducting seismic observatins in the Philippines rests with the Philippine Institute of Volcanology and Seismology(PHIVOLCS),In 2000,through a grant aid from the Japan International Cooperation Agency(JICA),the Philippine Seismic netowrk was upgraded to a digital system.As a result,a new set of seismic monitoring equipments was installed in all of the 34 PHIVOLCS seismic stations all over the country,Digital waveforms are now available for high level seismic data processing.and data acquisition and processing are now automated.Included in the upgrade is the provision of strong motion accelerographs in all stations whose data can now be used for studying ground motion and intensity attenuation relations,The new setup is now producing high-resolution data that can now be used for conducting basic seismological researches,Earthquake locations have now improved allowing for the modeling and delineation of earthquake source regions necessary for earthquake hazard studies.Current seismic hazard studies in the Philippines involve the estimation of ground motion using both probabilitstic and deterministic approaches,seismic microzonation studies of key cities using microtremor observations,paleoseismology and active faults mapping ,and identification of liquefaction-prone,landslide-prone nd tsunami-affected areas.The earthquake database is now being reviewed and completed with the addition of historical events and from data from regional databases,While studies of seismic hazards were primarily concentrated on a regional level ,PHIVOLCS is now focusing on doing these seismic hazard studies on a micriolevel.For Metro Manila,first generation hazard maps showing ground rupture,ground shaking and liquefaction hazards have recently been completed.Other large cities that are also at risk from large earthquakes are the next targets.The elements at risk such as population,lifelines,and vertical and horizontal structures for each of these urban centers are also being incorporated in the hazard maps for immediate use of planners,civil defense officials,policy-makers and engineers.The maps can also now be used to describe possible scenarios during times of strong events and how appropriate socio-economic and engineering responses could be designed.In addition,a rapid earthquake damage assessment system has been started which will attempt to produce immediate or rapid assessments identification of elements at risk durin times of strong earthquakes     

中国数字测震台网专业软件评测

介绍我国“十五”期间建设测震台网专业软件评测平台基本架构及原理,举例描述了专业软件评测平台运行效果.认为,测震专业软件测试与评估对我国“十五”测震台网建设项目实施和提高台网运行质量发挥重要作用.     

Countermeasures for and Experiences in Seismic Hazard Mitigation in Uganda

For earthquake-prone countries of the world, it is crucial to develop countermeasures and to share experiences in seismic hazard mitigation. The measures for seismic hazard mitigation are related to many factors, e.g., social, economic, and political. Research focused on modern science and technology paves the way for a better understanding of the earthquake phenomenon and helps to plan against its effects in seismically active areas.In this paper, we consider some of the events that occurred in earthquake-prone countries, both developing and developed, which caused devastation to the society and economy. These are mainly major events that have affected a considerable portion of the gross domestic product of these economies.Measures to mitigate seismic hazard are stressed and suggested. In addition, experiences in seismic hazard mitigation in Uganda and the rest of the world are discussed in general terms. Attention is given to geotectonic settings as well as the work of seismic hazard and disaster mana     

广州市部分城区地震小区划和震害预测

在特大城市开展地震小区划和震害预测在我国是一次新的尝试。广州密集的建筑物群、到处耸立的高楼大厦、横贯市区的高架路桥和立交桥，是其它中小城市不具有的。海量的数据资源、复杂的空间结构给地震灾害分析、空间数据处理带来了诸多挑战，在数据资料调查收集、分析处理技术、信息系统开发平台等方面要求更高，加深了研究难度。介绍了广州市部分城区地震小区划和震害预测的工作区概况、研究方法和内容及成果特点。     

减隔震桥梁设计方法及抗震性能研究综述

桥梁作为交通系统中的生命线工程,其抗震性能问题尤为重要。桥梁减隔震技术主要通过减隔震装置来降低结构的地震损伤,目前已发展成为提高强震区桥梁抗震能力的重要措施。为促进减隔震技术在中国桥梁工程领域的进一步发展,首先总结减隔震桥梁的设计方法,归纳其地震反应和震害情况,对采用不同减隔震装置桥梁的非线性动力性能、减隔震效果、地震随机响应、易损性及性能优化方法等研究情况进行梳理;其次,概述减隔震技术在斜交桥、曲线桥及铁路桥梁中的应用情况与研究进展,并介绍新型韧性抗震设计理念在桥梁工程领域中的应用情况和发展前景;最后,总结减隔震桥梁的试验研究情况,指出目前减隔震桥梁研究中的不足和发展趋势。     

深度学习在地震定位中的应用综述

近年来,深度学习的发展给科研人员开辟了地震定位研究的新思路,科研人员将深度学习技术应用于地震定位并取得了较好的效果。文章首先介绍根据神经网络的编码与解码对深度神经网络的分类,然后对深度学习的基本流程进行总结,最后对深度学习中广泛应用于地震定位的方法进行综述,总结不同方法的特点和实际应用情况。结果表明：深度学习方法能够实现地震事件的自动定位,且定位的精度较高,缩短了地震定位所需时间,在处理地震大数据方面也具有明显优势,能够克服目前传统地球物理方法在地震定位方面的一些不足之处。相信随着深度学习技术的进一步发展,必将更为广泛地应用于地震定位研究中。     

基于矢量切片的河南省地震构造查询系统

为促进河南省地震构造填图成果更好地服务于社会和相关地震地质研究,在填图数据深入加工处理基础上,设计并开发河南省地震构造查询系统。针对传统WebGIS系统加载地图慢、响应时间长的问题,在系统建设中引入矢量切片的思想,对矢量数据进行重新组织,结合HTML5 Canvas技术,对地图数据进行渲染,最终实现矢量数据在浏览器上地快速显示。同时考虑用户需要,实现地震、第四纪活动断层和断层剖面等数据的查询、显示与管理等综合应用。     

乌兰浩特地震台爆破与地震记录识别判据

选取乌兰浩特地震台爆破及地震波形数据记录,采用小波分析方法,提取地震及爆破的3种波形特征,使用v-SVC支持向量分类机进行分类能力的效果检验,结果表明,WPT(db4)+香农熵特征+v-SVC的组合最佳,可作为该台爆破与地震记录的快速识别判据。     

Wavenumber response of Shanghai Seismic array

Seismic array can be traced back to 1950s when it mainly aimed at detecting and distinguishing the signals of nuclear explosion and seismic signals. The research on seismic array includes seismic array techniques and applications of array in geophysics. Array techniques involve array design and data processing methods (Anne, 1990). Nowadays, the continuous development of seismic array￠s theory could relate to many scientific issues in geophysical field (Tormod, 1989; Mykkeltveit, Bungum, 1984). Seismic array is mainly applied to detect weak events. The response characteristic of array is an important indication of array￠s detection ability. Therefore, when we study an array or construct an array, one of the neces-sary works is to calculate the response characteristics of the array (Harjes, 1990). The aperture and layout of array are two dominating geometrical features. The typical aperture of interna-tional array is generally from several to tens kilometers. For instance, arrays with aperture of dozens kilometers aperture are KSA, WRA, YKA, etc, while arrays with several kilometer aperture are ARC, FIN, GEE, etc. Moreo-ver, in the view of array￠s layout, NOR, GER, etc have circle layout, while WRA, YKA, etc have decussating layout. This paper mainly discusses the relation between deployment of array and wavenumber response. With the example of constructing Shanghai Seismic Array, this paper provides one practical solution to search the proper array deployment. In this paper, the simple delay beam technique is adopted to calculate the response characteris-tics of array. Certainly, the different processing methods have different result, but the result from the simple delay beam processing could be enough to reflect the feature of an array.     

Identification of Local Seismic Events Using the Mikhnevo Seismic Array

A large number of events with sources in the immediate vicinity of an array are usually detected during seismological observations with seismic arrays. These events should be detected and correctly interpreted during processing of seismic array records in order to avoid clogging up the event catalog. This problem can be solved by classifying records of local events by genetic features and creating a databank with the most representative samples. The present paper considers local events recorded using a unique scientific setup, the Mikhnevo small aperture seismic array. Epicenters of local seismic events are located less than 5 km from the center of the array. Seismic responses of acoustic shock waves are also examined. Seismic events caused by anthropogenic sources are identified and classified using cluster, cross-correlation, and wavelet analysis. Events accompanied only by the arrival of surface waves, as well as events represented by body, surface, and acoustic waves, are identified. Shock wave events are classified as a separate category. A small group of supposedly natural weak events is also found. As a result, a databank of waveforms of local seismic events for the Mikhnevo seismic array is established. In the future, this will make it possible to automate their identification when investigating the seismicity of the East European Platform.