强震与微震观测系统的研究

本系统采用动圈型换能器(属于速度型换能器)加电子反馈形成在0.05Hz~50Hz的加速度仪特性,大大减小了甚低频率的影响,而其线性及动态范围也能满足实际使用的要求,避免了位移型换能器在低频段的较大误差,在地震观测中取得较好的效果。     

气象厅的强震波形观测、汇集与服务

目前,气象厅的数字强震波形观测和汇集业务是采用９５型烈度计实施的。现已在全日本以２０ｋｍ的间隔布设了约６００个采用９５型烈度计的全国性观测网（其中气象厅约１５０个,都市约１３０个,郡约１４０个,海啸地震早期检测网测点约１６０个,机动观测点约２０个）。...     

广东省强震观测的现状与展望

介绍了国内外以及广东省强震观测的历史现状，以大量的事实、数据说明广东省强震观测工作过去的辉煌和目前的落后状况，提出了我省今后开展强震工作的设想，特别指出要改变以前强震仪除被动等待强地震外就无所作为的情况，扩展用途，增加显示度，为用户着想。     

强震观测辅助教学与数据分析系统开发

强震观测是防震减灾工作中的重要环节,该项工作中涉及的部分概念相对比较抽象,对于本科教学而言,难度较大。为了提高教学效果,本研究基于MATLABGUI,开发了可视交互式的辅助教学与数据分析系统。算例表明,该系统可较好的满足强震观测相关的辅助教学和常规数据分析工作的需要。     

海底强震观测记录与地震动特性研究进展

随着海洋结构物的建设快速发展,为了解海底地震动相关特性,目前在建与已建成的海底强震台网逐年增加,得到的强震数据为海底地震动特性研究提供了重要资料。本文首先,统计了世界范围内现有海底强震台网的分布,并对强震台站信息及记录特点简要总结;其次,综述了基于海底强震记录以及数值计算等方法分析海底地震动特性的研究成果;并且,阐述了海底地震动在海洋工程中应用的研究现状;最后,基于现有研究成果,对海底地震动特性研究的前景进行讨论和展望。     

2003年1月4日新疆伽师5.4级地震的强震观测与分析

2003年1月4日新疆伽师县发生了5．4级地震，其宏观烈度为Ⅵ度。布设在伽师县城的强震固定台记录到5．4级主震及1次4．2级余震的加速度，其中一个地震的最大加速度值(水平分量)为66．12gal。初步分析这次强地震运动特性，得出两点结论：(1)强运动记录检验了投入使用的GDQJ-1A型仪器性能良好；(2)加速度时程记录表明垂直向P波初动尖锐、强震持时较长，最长约达7．5s，而水平向P波初动弱、强震持时较短，仅约2．5s。     

强震及工程震害数据库网站系统研究与实现

在调研国际上相关网站的基础上提出强震及工程震害数据库网站系统建设的总体设计方案，WEB数据库的数据结构和存档结构设计、Web数据库系统软硬件配置、Web数据库访问方法研究、检索技术研究及功能设计；在此基础上利用ASP技术建立强震及工程震害数据库网站；介绍该系统网站界面、系统维护、数据处理、地理信息系统；并对网络安全管理措施进行讨论。     

(七)断层失稳与强震短临前兆的观测、实验和模拟专题

“断层失稳与强震短临前兆的观测、实验和模拟”专题交流由构造物理与地震预报两个专业委员会联合举行.会议由构造物理专业委员会主任马胜利主持,包括马瑾院士在内的40多人参加了讨论会.     

滇西地区前兆观测资料的分类、分级与强震关系研究

采用两种方式对1990年以来滇西地区前兆台网观测资料的质量进行了分类、分级判别.第一种方式是根据各测项资料数据波动变化的程度,按A、B、C三类定性地划分资料的优劣程度,然后对各类资料的质量及地震预报能力进行分析研究;第二种方式是采用多种前兆异常提取方法对观测资料进行分析、处理,提取异常指标,根据各资料异常指标的映震效能,按A、B、C三个档次判定其优劣.研究结果表明,这两种方式得到的结果大致相同:(1)地形变和水位的观测资料质量最好,多为A类,具有较强的6级以上地震前兆信息;(2)水氡和水温观测资料质量一般,为B类,其异常信息主要对应5级地震,对6级以上地震的反应较迟钝;(3)水质、地磁、地电观测资料质量最差,为C类,但主要显示6级以上地震的异常信息.     

强震及工程震害基础资料数据库地理信息系统研究

基于MapInfo软件开发平台，建立了强震和工程震害空间数据库，对产生数据误差的来源进行分析和提出控制误差的方法，设计并实现了强震及工程震害数据地理信息系统，该系统界面主要用于Internet服务的后台图形制作，并为用户提供强震及震害数据的地理信息查询服务。     

Advanced sensitivity calibration of the Los Angeles strong motion array

Results are presented of recent sensitivity calibration of 76 accelerographs (SMA-1) of the Los Angeles Strong Motion Array. These have pendulum-like transducers and optical recording system. One characteristic of their design is off-axis sensitivity, which is magnified by transducer misalignment. A new calibration procedure was applied, which considers off-axis sensitivity and measures the angles of misalignment (φ and ψ), as well as the incident angle of the light beam onto the film (θ₀). These are required (1) for accurate estimation of sensitivity, and (2) for proper instrument correction of recorded accelerograms which considers also cross-axis sensitivity and misalignment. These effects are important near large acceleration peaks (approaching and exceeding 1g), e.g. like the ones recorded near the source of the 1994 Northridge earthquake (M_L=6·4). This earthquake was recorded by 65 stations of the Los Angeles Strong Motion Array, at epicentral distances from 2 to 85 km. Histograms showing distribution of the misalignment angles, light beam incidence angle θ₀ (for unloaded position) and the transducer sensitivities are presented. These indicate that the misalignment angles are typically 1–1·5°, but may also be 3–4°. Angle θ₀ (usually neglected), is mostly between ±8°, but may reach ±12°. Assuming θ₀=0 leads to systematically smaller values of the measured sensitivity (e.g. by ∼3% for θ₀=8° and ∼4% for θ₀=12°). Comparison of the newly measured sensitivities with those measured prior to installation (in 1979/1980), s^old, shows that, in general, the new values are systematically smaller. The difference is typically within 5 per cent, but in some cases is as large as 10 per cent. Other principal sources of the observed differences and their mechanisms are discussed. Those include long-term changes in the transducers (e.g. change of stiffness, reflected in changes of the natural frequency) and differences in the calibration procedure (e.g. errors associated with manual reading film records with tilt test data, and with transducer and instrument housing misalignment). The presented results may be considered typical of similar strong motion arrays worldwide. © 1998 John Wiley & Sons, Ltd.     

强震动记录数据格式研究

强震动记录数据是构建震害防御体系的重要数据基础,又是应急救援体系的重要参数指标。当今互联网技术及数据库技术的飞速发展,对数据共享及数据应用提供了必要条件,掌握多种强震动记数据格式是上述工作的良好基础。本文着重研究国内外5种主流的强震动记录数据格式(美国USGS格式、日本K-NET格式、美国PEER格式、土耳其格式、中国UA格式),针对目前地震应急需求,提出中国强震动记录数据格式发展建议。     

强地震动数据采集系统研究

本文介绍了GDQJ—1A型强地震动数据采集系统的结构原理和技术性能，它可用于强地震观测和工程振动测量。     

地震动强度与地震烈度速报研究

本在总结了美、日等国家和我国大陆与台湾地区基于实时或近实时强震台网的地震动强度（烈度）速报方法的基础上，对我国地震动强度（烈度）速报及计算机软件编制中的关键技术问题进行了讨论。     

水利水电工程强震监测和强震监测仪器

阐述了强震监测在实际工程中的作用,国内外强震监测的基本情况以及我国水利水电工程领域的强震安全监测的进展与现状,介绍了强震监测仪器的基本原理、特性及目前国内强震仪研制生产的技术水平和成果.介绍了水电工程领域强震监测工作中存在的实际问题.最后展望了强震监测工作在我国水电工程领域的发展趋势.     

Rupture mechanism and source parameters of Umbria-Marche mainshocks from strong motion data

A long sequence of earthquakes causing few casualties and considerable damage in a wide zone struck Central Italy starting on September 26, 1997. Theearthquakes are characterized by normal faulting mechanism, with a NE-SW(anti-Apenninic direction) tension axis. In this paper we analyze the accelerometric recordings collected by the accelerograph stations belonging to the National Accelerograph Network. About 10 stations were triggered by the mainshocks of the sequence. In particular, a small size foreshock and the two mainshocks that occurred on September,26 (00:33(GMT) M_W = 5.7 and 09:40 M_W = 6.0) have been recorded by two digital 3-C accelerometers located at near source distances (within 30 km from the faults). These records are relevant to investigate the detail of therupture kinematics, due to the close epicentral distance and azimuthallocation relative to the fault orientation and geometry. Using a trial and error approach we modeled the source mechanism through the fit of the arrival times, the apparent source time duration, the main polarization features and the entire waveforms of the recorded signals, in order to get some insight on the rupture evolution, the location of the fracture origin point and the fault geometry. Based on this fault kinematic model, inferences on fault slip distribution are obtained by modeling the S acceleration waveform, comparing the ray theory synthetics with 1–5 Hz band filtered ground velocity records.The final model shows that the seismic ruptures occurred along two adjacent,sub-parallel, low angle dipping normal faults. Ruptures bothnucleated from the fault bottom and propagated up-dip, showing differentrupture velocity and length. The presence of a transfer zone (barrier)can be suggested by the mainshocks rupture evolution. This transfer zonehas probably controlled the amplitude increase of local stressreleased by the first rupture at its NW edge which triggered about 9 hourslater the second rupture. The inferred model was used to compute the predictedground acceleration in the near source range, using a hybridstatistical-deterministic approach.A similar trial and error method has been also applied to the October 14, 199715:23 earthquake (M_W = 5.6). The inferred kinematic model indicates a rupture nucleating from the faultbottom and propagating up-dip, toward the SE direction. Thus the three mainshocks ruptured distinct fault segments, adjacent and slightly offsetfrom one to another.     

Site effects on strong ground motion

A review of some of the available methods to study the effects of site conditions on strong ground motion is presented. The need of unified treatment of source, path and side effects in the assessment of seismic risk is pointed out.     

嵌入式Linux系统下强震实时数据与地震流服务通信传输的实现

介绍嵌入式系统的概念、MiniSEED数据格式和NetSeis/IP协议,具体地阐述在嵌入式系统下,MiniSEED数据封装及地震数据流上载传输的实现.