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山西对地震电磁波观测仪器的研制已有10多年的历史,经不断改进,研制出DMJ—85A脉冲记录仪,与“磁传感器”配套使用,一年多实验观测表明,仪器性能稳定、故障率低、抗干扰能力强、观测前兆电磁脉冲灵敏度高、自动化程度高、节能省电、操作简便、可无人值守.可用来观测地震电磁前兆异常. 相似文献
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根据地震预报的需要,我们研制了一种高频地震记录仪。采用熏烟或墨水记录。仪器频带2～120Hz(-3db);总功耗约0.4瓦,重量24公斤。滚筒速度分二档:240mm/分、360mm/分(或120mm/分,240mm/分),在240mm/分速度时,仪器可连续记录12小时。 本仪器在云南省剑川、云龙和鹤庆等地,以及贵州六枝地区做过流动观测,并在昆明、昭通、易门和海口做过半年至一年以上的长期试用性观测。流动观测期间,记到不少零级以下的地震。有的地震卓越频率大于40周,震级<-1.7;根据估算,在频率100Hz时,可以观测到-3级左右的地震。长期流动和固定观测证明了仪器的稳定性、可靠性都是良好的。 试验观测表明:这种仪器对监测极微震活动、地声观测和研究断层的现代活动性都是一种有用的仪器。因为采取了可见记录,观测结果更直观,维修管理方便,适于流动观测。如果与慢速磁带机相结合,可使高频地震观测更为有效和完善。 相似文献
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前言 CJ_6地磁经纬仪是我国自行设计、制造的一种地磁观测仪器。用于测量地磁偏角(D)和水平强度(H)的变化。经与标准仪比测后,则可观测地磁场的绝对值。在台站进行定点观测时,配以质子旋进磁力仪(观测总强度F)可测定磁变仪记录的D、H,Z基线值,进而得到所在地区地磁七要素的变化。 1981年底,配备给成都地磁台的CJ_6地磁经纬仪经与北京、武汉地磁台比测后正式投入观测。四年多来,仪器基本处于正常工作状态,取得了连续的观测成果。本文试图通过分析、讨论,对观测成果进行初步的评价,并提出地磁工作的建议。 相似文献
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China is one of the earliest countries to start borehole strain observation aiming to predicting earthquake.YRY-4 and other borehole strain instruments developed by China have reached the world advanced level,with a resolution of 10-10 and can work stably.In order to capture the tectonic stress signals and analyze the relationship with seismicity,it is firstly necessary to identify and exclude the non-structure stress signals (caused e.g.by rainfall,pressure change,groundwater level fluctuation,river fluctuation etc).Annual strain change signals have been observed by YRY-4 borehole strain instrument at some stations (e.g.Guzan station in Dadu River valley).The signal is on the wave crest in spring and trough in autumn.Up to now,no relative papers have interpreted the physical mechanism causing such strain signals.In this paper,we manage to explain the physical mechanism by using numerical simulation.Considering the terrain factor of Dadu River valley,we set up a 3D finite-lement thermoelastic coupling model to compute the heat stress caused by annual change of surface temperature.The computing results are in good accordance with observation values,which illustrates that the annual change of strain signals is caused by annual change of surface temperature.We suggest that high-resolution borehole strain instrument (e.g.YRY-4 strain instrument) should avoid installing in a terribly undulate area,but choose a flat one.Although the strain signal with an annual change is a noise signal,to a certain extent,the signal illustrates that the current borehole strain instrument has a high resolution.This gives us more confidence to use this instrument to measure the structural strain. 相似文献
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作为地壳形变监测的一种手段,地应变观测可监测微尺度下的地表应变变化,其分辨率一般为10-9。目前地震地球物理观测台网在网运行的洞体应变观测台站有111个,分量钻孔应变观测站59个,钻孔体应变测站有68个,产出数据包括原始观测数据、台站预处理数据和产品数据,可为地震研究、地球动力学研究提供重要的数据支撑。 相似文献
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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
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Meng Jianguo Zhang Hui Jiang Qifeng Lu Shuangling Li Huiling Yang Bin Zhou Juntai 《中国地震研究》2017,31(4):538-547
Based on the cave strain observation data in 2013 at Tai'an seismic station,we use the Venedikov harmonic analysis method to calculate the cave strain measurement and phase lag of the tide factor, and qualitatively evaluate the stability of the tidal factor for observational data evaluation. At the same time, the two measurement items of the observation instrument are calculated,and the correlation strain parameters are extracted and compared. On this basis,the strain parameter time series calculation is carried out on the data quality of Taian seismic station,which is relatively stable,and the 2 sets of instruments are compared. Through the analysis, it is found that the stress field is abnormal,and the corresponding relationship between the anomaly of the stress field and the gravity field is compared and analyzed. 相似文献
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Introduction The Earth′s crust deforms in the regional tectonic stress field. Borehole strain observation isone important means for studies on the crustal deformation and the stress field. QIU and ZHANG(2002) have introduced the current situation of borehole strain observation in China. OutsideChina, early in September of 1968, Sacks of Carnegie Institution of Washington and Evertson ofUniversity of Texas firstly invented a borehole dilatometer in the world (Sacks, Evertson, 197… 相似文献
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Borehole strain observation is playing an increasingly important role in the study on the crustal movements. It has been used
by many countries such as China, USA, Japan, Peru, Australia, South Africa, Iceland and Italy, in research fields of plate
tectonics, earthquake, volcanic eruption, dam safety, oil field subsidence, mining collapse and so on. Borehole strainmeter
has been improved rapidly and tends to get more and more components included in one probe. Based on observations by this kind
of instruments, studies on seismic strain step, slow earthquake, earthquake precursor and volcanic eruption forecasting have
made remarkable achievements. In the coming years, borehole strain observation is going to become one major goedetic means,
together with GPS and InSAR.
Foundation item: National Natural Science Foundation of China (40374011) and Joint Seismological Foundation of China (1040037). 相似文献
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2008年8月30日的攀枝花仁和—凉山州会理间6.1级地震前,距离最近的攀枝花南山定点形变台多套仪器监测到了明显的异常变化。本文对此次6.1级地震前的多套形变仪器记录异常作了总结研究,各套仪器监测在出现中期异常的同时,又存在短临异常。结果表明:南山地震台石英摆仪观测NS向分量存在趋势变化偏小异常的同时,又存在短期突变加速异常;长水管仪的异常变化表现为加速和转向变化;石英伸缩仪NS向分量的异常变化在震前两天出现,表现为原始记录曲线、整点值的畸变。结合历史震例总结显示:攀枝花南山台各套形变监测短临异常的开始或结束时间对台站周边未来地震的时间有一定指示意义,即异常开始后一至两个月内,在监测台站周边地区可能发生6级以上地震;各监测分量方向异常变化对台站周边未来地震可能的方位也有一定的指示意义;异常的变化幅度与未来地震震级关系不明显。 相似文献
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CBT型钻孔倾斜传感器是我国地倾斜测量的重要仪器，只有保证倾斜传感器的高灵敏度和高自身稳定性，才能获得优质的观测数据。以往采用热处理和自然时效的方式消除传感器残余应力，进行预老化处理，提高传感器自身稳定性。该处理方法虽行之有效，但周期较长，难以满足日益增加的台站建设需要。为此，本文构建实验室倾斜传感器整机预老化系统，开展倾斜传感器快速消除残余应力试验，并跟踪传感器样品在阿图什台站的安装使用效果。通过实践证明，振动时效预老化工艺可有效消除传感器残余应力，有利于倾斜传感器的快速稳定。 相似文献
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针对河北永年地震台伸缩仪EW分量2015年5月11日起出现的加速拉张变化,从仪器工作状态、洞室环境、气象条件和外界环境干扰等方面,进行调查分析。利用3种荷载模型计算道路施工荷载变化可能引起的应变变化量,并结合其他形变测项变化特征进行论证,认为永年伸缩仪张性变化是区域应力场调整的结果。 相似文献