地震数据处理系统Earthworm在福建地震预警系统项目中的应用     

方伟华  周蓝捷  闫培  李文惠  汪豪 《震灾防御技术》2018,13(1):226-236

本文介绍了USGS（美国地质勘探局）开发的Earthworm系统在福建地震预警系统项目中的应用。该系统为开源软件,由C语言编写,由不同模块组建而成,每个模块实现不同的功能,主要包括数据接收模块、P波拾取模块、地震定位报告产出模块、地震事件图件绘制模块、地震波存储容器等。同时,用户可以根据自己的需求编写相应的功能模块。文章对该系统的应用进行了介绍,内容包括Earthworm系统的组织架构、业务流程、软件模块的主要功能搭建与配置及软件模块之间的逻辑关系等,目的在于介绍该系统的架构方法与使用心得,促进该系统在地震行业内得到应用与推广。  相似文献   

Review Paper: A semi‐empirical model of strain sensitivity for 4D seismic interpretation          下载免费PDF全文

Colin MacBeth  Asiya Kudarova  Paul Hatchell 《Geophysical Prospecting》2018,66(7):1327-1348

We reformulate the original model of Hatchell and Bourne and Røste, Stovas and Landrø that couples fractional velocity change to subsurface strain via a fundamental constant R. The new model combines elastic compressibility of a dual‐porosity system for a sand–shale mixture with horizontal planes of inter‐granular weakness. The majority of observed R‐factor magnitudes from post‐stack 4D seismic data in both the reservoir and overburden can thus be explained. R is predicted to depend strongly on lithology and also initial strain state. The model is also extended to predict the observed angle‐dependence of time‐lapse time‐shifts from pre‐stack data. An expression for the gradient of time‐shift with incidence angle is obtained in terms of the background V_P/V_S, and also the ratio of tangential to normal compliances B_T/B_N representing loss or creation of inter‐granular coupling. If accurately estimated from data, this compliance ratio can be used as an additional parameter to assess the post‐production state of the overburden. It is concluded that whilst R remains the over‐arching parameter controlling the magnitude of time‐shifts measured from 4D seismic data, B_T/B_N is a subtler parameter that may also prove of future value.  相似文献   

在X模式单道成像与观测系统重复性关系下的多道观测系统重复性          下载免费PDF全文

辛秀艳  董凤树  符力耘  全海燕  罗敏学  胡斌  岳悦 《地球物理学报》2019,62(5):1849-1860

时移地震中新提出的多道观测系统重复性,逐一应用于面元,可以给出每个面元单一的观测系统重复性,形成对应叠后成像的地震道重复性的面分布,对于评估时移地震重复性具有重要意义.前人研究抽象了多道间观测系统重复性与单道间观测系统重复性的关系,给出了多道观测系统重复性的衡量方法及其理论依据.其理论中依赖了地震数据重复性与单道观测系统重复性的线性关系模型,而这一关系在单道观测系统重复性的有限范围内较为准确.针对这一问题,本文提出了X模式拟合的关系模型,与全范围的单道地震数据重复性随观测系统重复性的变化趋势更好地吻合,并采用对大单道观测系统重复性的向X节点的收缩,使原多道观测系统重复性的相应关系在整个数据范围内基本成立.基于实际数据的研究表现了该方法的数据分析结果的新特性和应用价值.  相似文献   

徐州地震台2016年11月—2017年YRY-4分量钻孔应变仪异常核实     

祁蒙  吴继炜  张岑  高明智  郝冉 《地震地磁观测与研究》2020,41(5):83-89

2016年11月-2017年,徐州地震台YRY-4分量钻孔应变曲线出现"漏斗"状向下凹陷的压性变化,从场地环境、观测环境、观测系统进行现场核实,并对异常期间的观测数据进行对比分析,排除外界干扰及仪器自身问题,认为此次数据畸变可能反映了地下应力的真实变化,应为地下地质构造发生变化所致。  相似文献   

美国TXAR台阵建设过程     

王志宇  郝春月 《地震地磁观测与研究》2020,41(6):144-149

TXAR台阵位于美国德克萨斯州,是IMS下属的主要地震台阵之一。该台阵将台站数目压缩到9个,采用无线遥测通讯方式,减少了建设和运行维护成本。其地震计室采用钻孔加套管的形式,具有安装简易、密封性好的优点。台阵采用无人值守设计,使用太阳能板、UPS电池和燃油发电机等多种供电方式,具有可靠稳定的性能。  相似文献   

2017年9月2日宁夏固原4.6级地震震例分析     

李文君  曾宪伟  卫定军  李国斌  罗国富 《地震地磁观测与研究》2020,(1):40-47

2017年9月2日宁夏固原市原州区发生4.6级地震.通过对此次地震的回顾和总结,得到以下结论:①固原4.6级地震为孤立型地震;余震主要分布在主震震中西南侧,结合震源机制节面解,初步判定NW向节面应为此次地震的发震断层面,震源错动方式为左旋走滑兼具逆冲;震源机制解最佳拟合深度为9 km;震源机制解参数为节面Ⅰ:走向34°、倾角62°、滑动角174°,节面Ⅱ:走向127°、倾角85°、滑动角28°;②固原4.6级地震前存在前震活动、小震调制异常以及固原地震窗异常;③海原小山钻孔应变异常变化与固原4.6级地震有关,且与该测项预测指标已有的研究结果较吻合,但此次地震震级比预计震级偏大;④固原地震台地电阻率和地磁谐波振幅比异常期间发生了3次中强地震,其中,2017年5月17—20日,固原地震台地电阻率EW向出现快速下降,之后呈低值变化;固原地震台地磁谐波振幅比NS向从2014年开始经历下降—转折—回升过程,具有良好的映震效能.  相似文献   

Assessment of Primary Production by Statistical Analysis of Water‐quality Data     

Wilhelm Petersen  Ulrich Callies 《洁净——土壤、空气、水》2002,30(1):34-40

Time series of weekly water‐quality data at Schnackenburg on the Elbe River (1985—2000) were subjected to principal component analysis (PCA). Considering the amplitudes of composite patterns of variables is a step towards a process‐oriented interpretation of waterquality data. One specific objective was to investigate the impact of improved water quality after the German reunification in 1990 on primary production and the oxygen budget. To discriminate anthropogenic signals from natural fluctuations a separation of the impact of discharge was attempted based on a linear regression approach. A dominant pattern of co‐variation in the residual data could be attributed to biological activity (primary production). The most relevant variables of this 'biomode' are oxygen saturation, pH, and orthophosphate. We conclude that multivariate statistical analysis of water‐quality data can help to estimate primary production when direct observations of algal concentrations are missing. In the years from 1998—2000 the trend of the ‘biomode’ indicates an increased load of oxygen consuming biomass caused by enhanced primary production in the middle stretches of the Elbe River which corresponds with the observation of more severe oxygen deficits in the tidal section of the river.  相似文献   

测震数据实时备份与灾备处理中心建设     

李正楷  于悦颖  杨驰 《地震地磁观测与研究》2018,39(5):205-210

以江苏省测震台网为例,介绍灾备处理中心数据传输方法、系统框架、子系统建设关键以及存在的问题和解决方案,并对运行效果给予评价。江苏省测震台网采用SDH/MSTP有线专线和4G无线网络同步实时传输方式建立备份信道,原主信道数据由数采以太网口采集,备份信道数据由数采串口采集,从而实现测震数据的实时备份。现已建成溧阳地震台灾备处理中心,部署实时波形汇集交换、数据存储备份、自动速报、人工速报和信息发布、运行监控5个子系统,确保地震监测系统安全稳定运行。  相似文献   

Scale effects on modelling the seismic signature of gas: results from an outcrop analogue          下载免费PDF全文

Maria‐Daphne Mangriotis  Colin MacBeth  Angel Briceño 《Geophysical Prospecting》2018,66(6):1159-1179

Numerous examples of reservoir fields from continental and marine environments involve thin‐bedded geology, yet, the inter‐relationship between thin‐bedded geology, fluid flow and seismic wave propagation is poorly understood. In this paper, we explore the 4D seismic signature due to saturation changes of gas within thin layers, and address the challenge of identifying the relevant scales and properties, which correctly define the geology, fluid flow and seismic wave propagation in the field. Based on the study of an outcrop analogue for a thin‐bedded turbidite, we model the time‐lapse seismic response to fluid saturation changes for different levels of model scale, and explore discrepancies in quantitative seismic attributes caused by upscaling. Our model reflects the geological complexity associated with thin‐bedded turbidites, and its coupling to fluid flow, which in turn affects the gas saturation distribution in space, and its time‐lapse seismic imprint. Rock matrix and fluid properties are modelled after selected fields to reproduce representative field models with realistic impedance contrasts. In addition, seismic modelling includes multiples, in order to assess their contribution in seismic propagation through thin gas layers. Our results show that multiples could contribute significantly to the measured amplitudes in the case of thin‐bedded geology. This suggests that forward/inverse modelling involving the flow simulation and seismic domains used in time‐lapse seismic interpretation should account for thin layers, when these are present in the geological setting.  相似文献   

Review Paper: Post-stack 4D seismic time-shifts: Interpretation and evaluation     

Colin MacBeth  Maria-Daphne Mangriotis  Hamed Amini 《Geophysical Prospecting》2019,67(1):3-31

A review and analysis of post-stack time-lapse time-shifts has been carried out that covers published literature supplemented by in-house datasets available to the authors. Time-shift data are classified into those originating from geomechanical effects and those due to fluid saturation changes. From these data, conclusions are drawn regarding the effectiveness of post-stack time-shifts for overburden and reservoir monitoring purposes. A variety of field examples are shown that display the range and magnitude of variation for each class of application. The underlying physical mechanisms creating these time-shifts are then described, and linked to a series of generic and field-specific rock physics calculations that predict their magnitudes. These calculations serve as a guide for practitioners wishing to utilize this information on their own datasets. Conclusions are drawn regarding the reliability of this attribute for monitoring purposes, and the extent to which further development is required and how it should be reported by authors.  相似文献