Aswan telemetered seismograph network

A telemetered network of 8 short-period seismograph stations was installed at Aswan Reservoir in July 1982 to monitor induced seismicity near the site of a magnitude 5 earthquake which occurred in November 1981. A continuous monitor of the seismicity is provided by pen and ink recording of 4 stations. An event detector is used to identify events of interest, for which all of the stations are recorded on magnetic tape. Approximate displacement magnifications are 40, 000 at 1 hz with a maximum of 500, 000 at 20 hz.     

武都水利枢纽工程水库数字遥测地震台网布局设计

综合考虑诱震活动断裂、水库荷载中心区域、水工设施和大坝、库区周边其他重要地区、遥测质量高和建设维护费用省、系统可靠性高等因素,进行武都台网布局设计。     

陕西省数字地震台网与模拟地震台网地震参数比较

对1998年1月至2001年12月之间,陕西省数字地震台网与模拟地震台网测定的地震参数作了比较,并进行了讨论。     

数字遥测地震台网中的无线技术

介绍了超短波、微波扩频及卫星技术在数字遥测地震台网中的应用领域及优势,根据各频段无线电波的传播特点和数字遥测台及中继站数据复分复接技术要求,阐述了无线技术在数字遥测地震观测系统中实现的方式和步骤,并叙述了超短波及无线扩频技术在合肥数字遥测地震台网的应用以及在实施过程中需注意的几个技术环节.     

地震仪器中应用的网络通讯技术研究

网络通讯是决定地震勘探仪器系统性能和规模的关键核心技术之一,按照所采用的数据传输方式,数字地震仪目前可分为有线遥测地震仪、无线遥测地震仪和无缆存储式地震仪.本文分别举例介绍了三类地震勘探仪器中应用的经典地震网络通讯技术,并对其设计理念、网络通讯原理、通信构架、通信协议进行了分析和对比,针对有线地震仪器的电缆管理难、无线地震仪器的数据传输稳定性差和无缆存储式地震仪缺少质量监控手段的问题,讨论了无线监控与本地存储相结合的地震网络通讯技术方案,提出了基于宽带无线通信技术的无缆无线混合型地震仪的设想.     

Travel times ofP-waves for the Swedish-Finnish seismograph network

Summary About 360 seismic events from almost all directions recorded at 13 seismological observatories in Sweden and Finland have been investigated. The depths of these events vary from the surface to 650 km and the epicentral distances from 9° to 119° with fairly even coverage. The two most separated stations in this array are about 15° apart (Karlskrona in Sweden and Kevo in Finland). Comparison of observed travel-time curves and their slope with those ofJeffreys-Bullen andHerrin are made. Generally, the observed travel times are earlier than theJeffreys-Bullen times and later than theHerrin ones. Path and depth effects on residuals with respect to the two given tables are studied, and station corrections and source corrections are estimated. Global and regional travel-time tables of theP-wave have been constructed for this network of stations.On leave from Geophysical Institute, Tehran University, Tehran, Iran     

Comparison between earthquake magnitudes determined by China seismograph network and US seismograph network (Ⅱ):Surface wave magnitude

By using orthogonal regression method, a systematic comparison is made between surface wave magnitudes determined by Institute of Geophysics of China Earthquake Administration (IGCEA) and National Earthquake Information Center of US Geological Survey (USGS/NEIC) on the basis of observation data collected by the two institutions between 1983 and 2004. A formula is obtained which reveals the relationship between surface wave magnitudes determined by China seismograph network and US seismograph network. The result shows that, as different calculation formulae and observational instruments are used, surface wave magnitude determined by IGCEA is generally greater by 0.2 than that determined by NEIC: for M=3.5～4.5 earthquakes, it is greater by 0.3;for M=5.0～6.5 earthquakes, it is greater by 0.2;and for M≥7.0 earthquakes, it is greater by no more than 0.1.     

Comparison between earthquake magnitudes determined by China seismograph network and US seismograph network （Ⅱ）： Surface wave magnitude

By using orthogonal regression method, a systematic comparison is made between surface wave magnitudes determined by Institute of Geophysics of China Earthquake Administration （IGCEA） and National Earthquake Information Center of US Geological Survey （USGS/NEIC） on the basis of observation data collected by the two institutions between 1983 and 2004. A formula is obtained which reveals the relationship between surface wave magnitudes determined by China seismograph network and US seismograph network. The result shows that, as different calculation formulae and observational instruments are used, surface wave magnitude determined by IGCEA is generally greater by 0.2 than that determined by NEIC： for M=3.5-4.5 earthquakes, it is greater by 0.3; for M=5.0-6.5 earthquakes, it is greater by 0.2; and for M≥7.0 earthquakes, it is greater by no more than 0.1.     

Comparison between earthquake magni-tudes determined by China seismograph network and US seismograph network (II): Surface wave magnitude

Introduction Earthquake magnitude is the most common measure of an earthquake′s size,and is one of the basic parameters of an earthquake.There are three most familiar scales of earthquake magnitude:ML(local earthquake magnitude),MS(surface wave magnitude)and mB/mb(body wave magni-tude).Richter(1935)introduced ML when studying earthquakes in Southern California.In1945,Gutenberg(1945a)put forward surface wave magnitude scale to determine earthquake magnitude(MS)using surface waves(20s)of s…     

新型数字强震仪关键技术分析

新型强震仪采用高速信号处理器为控制核心,24位∑- △A/D转换器与数字滤波器构成的3通道信号采集系统.仪器采用大容量CF卡记录采集数据,具有TCP/IP协议的网络通信接口,内置GSM通信模块,内置嵌入式网页服务器,可以通过浏览器与发送中文短信的方式对仪器进行监控.详细分析了仪器所采用的烈度算法与触发滤波器的特性和设计...     

连续波形:数字地震台网的新前沿

21世纪以来,连续波形的自动处理成为数字地震台网的一个新的前沿领域。本文通过深低频脉动(LFT,Low Frequency Tremor)、噪声相关函数(NCF,Noise Correlation Function)、"重复地震"等3个方面,指出在这一新的前沿领域中,中国数字地震观测系统正面临巨大的发展机遇。与此相应,在中国地震台网的下一步发展中,应重视连续波形的记录,并将连续波形的自动处理作为一个发展重点来考虑。     

The Uppsala seismograph array station

Summary The Seismological Institute at Uppsala, Sweden, has operated a triangular array station for one year, August 1969 to August 1970. The triangle is almost equilateral with around 100 km side, with one corner at Uppsala and the other two at Hedemora and Kungsör. Short-period vertical-component seismographs of type Grenet-Coulomb are used. The signals are transmitted over commercial telephone lines to the central recording unit at Uppsala. This paper describes all technical details of the system, with particular emphasis on the signal transmission. Experiences from the operation are given. In spite of only three points in the array, it serves its purposes very well, primarily because of its location on very homogeneous ground, the Baltic shield. Moreover, the installation and operation of such an array is generally possible within the limited budgets of a university Institute.     

区域数字地震台网开展近场源剪切波分裂的实用化研究

作者最近在进行台湾微震台网(郑秀芬等,2005)产出的台湾西南部嘉义地震序列的剪切波分裂应力预测研究中,在上地壳各向异性的近场源剪切波分裂方法、基本原理、应用领域和数据处理等方面,开展了深入研究,取得了一定的成果。本文通过浅显易懂的解释说明,希望地震台网、地震台站和开展相关研究工作的数据处理人员能够对各向异性、剪切波分裂等概念有所了解,对所处地区有可能开展的研究方向有所把握,并积极开展常规准实时剪切波分裂研究,为提升台网和台站工作人员的科研能力,促进科研成果和方法的实用化转化提供借鉴和参考。     

中国数字地震台网(CDSN)的近期发展

中国数字地震台网（CDSN）自20世纪80年代建成并投入运行以来,有力地促进了我国的数字地震学研究,扩大并加深了我们对地壳、地球内部构造和地震震源过程的认识,从而有助于地震预报和减轻地震灾害的研究工作．本文阐述了基于CDSN二期技术改造建立的CDSN数据通信系统,研发CDSN数字地震实时分析系统的进展．     

Comparison between earthquake magnitudes determined by China seismograph network and US seismograph networks (Ⅰ): Body wave magnitude

By using orthogonal regression method, a systematic comparison is made between body wave magnitudes determined by Institute of Geophysics of China Earthquake Administration (IGCEA) and National Earthquake Information Center of US Geological Survey (USGS/NEIC) on the basis of observation data from China and US seismograph networks between 1983 and 2004. The result of orthogonal regression shows no systematic error between body wave magnitude mb determined by IGCEA and mb (NEIC). Provided that mb (NEIC) is taken as the benchmark, body wave magnitude determined by IGCEA is greater by 0.2～0.1 than the magnitude determined by NEIC for M=3.5～4.5 earthquakes; for M=5.0～5.5 earthquakes, there is no difference; and for M≥6.0 earthquakes, it is smaller by no more than 0.2. This is consistent with the result of comparison by IDC (International Data Center).     

Comparison between earthquake magnitudes determined by China seismograph network and US seismograph networks (I): Body wave magnitude

Introduction Gutenberg (1945a, b) introduced body wave magnitude based on P, PP and S waves (with a period of 0.5~12.0 s) of teleseismic events. Body wave magnitude includes mb determined with short-period seismograph and mB determined with middle- and long-period seismographs. Some-times it is written as m, which is referred to as unified earthquake magnitude. mb represents earth-quake magnitude measured with body wave amplitude around 1 s, while mB represents earthquake magnitude measured …     

龙滩水电工程数字遥测地震台网监测能力检验

阐述了数字地震台网地震监测能力的计算方法,根据龙滩数字遥测地震台网监测要求与设计监测能力,采用该台网2006年1月至2007年11月期间记录到的833个ME1．5以下地震,检验和分析了台网的实际监测能力,结果表明,台网的实际监测能力达到设计要求。     

我国现代地震台网观测技术的开拓者

引言 张奕麟先生是我国现代地震台网观测技术的开拓者和奠基人之一.20世纪60年代至90年代,他致力于现代模拟和数字地震台网观测技术研究,为推动我国地震观测技术现代化做出了突出贡献.本文就他在北京八条线遥测地震台网、国家地震局768工程,以及中国数字地震台网(CDSN)等科技项目中,发挥的历史作用做简要回顾.     

The lunar barometric tide in New Zealand

The lunar barometric tide has been determined with reasonable accuracy, on an annual and seasonal basis, at five stations on the mainland of New Zealand and at three of the outlying islands. The determinations show that in the New Zealand region the lunar tide has a larger amplitude and smaller phase than might have been expected from previously available southern-hemisphere results. In general, the seasonal variation of phase in the New Zealand region conforms to the currently recognised global pattern, with the J-season phase greater than that of the D-season. Similarly, the amplitude variation tends to support the suggestion that, south of latitude 30°S, the D-season amplitude is greater than that of the J-season. Approximate tests are introduced and used to assess the statistical significance of some of the apparent differences in amplitude and phase made evident by the analysis. These assessments indicate that although many of the apparent differences may be attributed to sampling fluctuations, the main regional anomalies in amplitude and phase are likely to be real. It is suggested that these anomalies may indicate a significant regional input of tidal energy to the atmosphere (at the lower boundary) from the Pacific oceanic tide.