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1.
昌黎井水位、水氡趋势动态特征分析   总被引:1,自引:0,他引:1  
分析了昌黎井2004年洗井前后水位、水氡的趋势动态特征,认为洗井是造成水位和水氡两者趋势变化不同步的主要原因之一.经过观测环境调查,判定2009年以来水位趋势下降并打破年变规律与附近温泉井抽水有关.  相似文献   

2.
平谷马坊井成井于2008年,是北京北部地区重要流体观测井,井孔结构完整,但水位、水温映震不灵敏,观测信息有限。为提高观测数据质量,对井孔进行射孔改造,增加含水层厚度,洗井及清淤施工增大含水层渗透性。改造后观测井水位具有明显潮汐效应,水温观测数据内在质量明显提高,其映震能力加大。平谷马坊井改造效果良好,为流体观测同类井孔的重新利用提供了借鉴。  相似文献   

3.
平谷马坊井成井于2008年,是北京北部地区重要流体观测井,井孔结构完整,但水位、水温映震不灵敏,观测信息有限。为提高观测数据质量,对井孔进行射孔改造,增加含水层厚度,洗井及清淤施工增大含水层渗透性。改造后观测井水位具有明显潮汐效应,水温观测数据内在质量明显提高,其映震能力加大。平谷马坊井改造效果良好,为流体观测同类井孔的重新利用提供了借鉴。  相似文献   

4.
简要介绍地电场观测方法和拉萨地磁台地电场观测基本概况的基础上,对拉萨地磁台 2008年6月1日至12月31日期间的地电场观测数据,特别是当雄6.6级地震前后的地电场数据变化,进行了分析和讨论.认为①该观测结果受观测系统和观测环境等人为因素的影响比较小,观测数据具有较高的可靠性;②该数据变化过程与当雄6.6级地震序列具有较大的关联性;③对该数据的分析研究在探讨地震地电场变化机理等方面具有一定的代表性.  相似文献   

5.
选取成都基准地震台地电场观测数据,对其进行数据的可靠性、正常变化特征、干扰因素等的分析研究,获取地电场观测数据的变化特征及规律;统计出邻区符合条件的灾害性地震,研究成都基准台地电场观测数据在这些破坏性地震前后的变化特征,探索观测数据在周边破坏性地震前后变化规律及短临异常特征,并进行关联分析。  相似文献   

6.
基于成都台长期的地电阻率观测数据在时域的变化规律,对该地区观测数据的正常变化特征、干扰因素、可靠性进行分析研究,获取观测数据的动态特征。同时通过成都台地电阻率观测数据在汶川MS8.0、芦山MS7.0等地震前后的变化动态,研究地电阻率观测数据在灾害性地震前后的趋势性及短临异常特征,并对其进行映震分析。分析表明:视电阻率的异常变化与Ms7.0以上强震的发生存在一定的映震关系。  相似文献   

7.
2007—2019年洱源台洞体应变及辅助硐室温度的长期观测数据中存在明显的分段特征,通过多测项数据对比、日志追踪、现场调查等方法分析查找导致数据分段的近场环境事件。结果表明:近场环境的某些细微变化能够引起形变观测数据振幅、频率、组分、稳定性的变化,导致前后数据的不一致,从而影响观测数据的稳定性。因此,必须尽可能保持近场环境恒久不变以确保观测数据的长期稳定性,从而避免前后数据可比性降低影响前兆数据在中短期地震预测中的应用价值。  相似文献   

8.
20世纪90年代以来,“网络工程”和“陆态网络”积累了十余年的GNSS观测数据.以1999-2011年西藏、青海地区GPS区域站观测结果为基础,利用多核函数法和球面应变模型,计算了青藏高原中南部地区区域整体无旋转框架下的运动场和应变量,对汶川地震前后两个时段的结果作对比分析.  相似文献   

9.
《高原地震》2021,33(2)
国家烈度速报与预警工程重庆子项目实施过程中,部分台站地震计坑因潮湿渗水,改造为地表摆墩观测。对改造前后的观测数据进行功率谱密度计算,用1/3倍频程滤波器在1~20 Hz频带范围内计算地噪声水平,进而得到台站有效测量动态范围。对比分析台站改造前后数据计算结果,显示改造后台站噪声水平有所增加,其中东西向、南北向最大增加9 dB,垂直向最大增加5 dB,但环境地噪声水平仍符合观测规范要求。鉴于地震计墩改造对观测数据产生影响,本文提出了更为合理的浅式半地下室改造方案。  相似文献   

10.
汶川MS8.0、 海地MW7.0地震 电磁信号小波能谱分析   总被引:2,自引:0,他引:2       下载免费PDF全文
应用小波变换方法处理了2008年汶川MS8.0地震前后成都、 江油台地电阻率观测数据及汶川地震、 2010年海地MW7.0地震前后DEMETER卫星记录的电离层磁场观测数据, 研究了地电阻率和电离层磁场的小波能谱及其相对变化.结果表明: ① 对应汶川大震前成都台N58°E测道地电阻率中期下降变化和短期上升变化的时段, 地电阻率小波能谱相对变化显著增大, 江油台N10°E测道地电阻率在主震前记录到了临震异常, 在临近主震前后, 电离层磁场特别是x分量的能谱及相对变化显著增大, 展现了与汶川大震明显对应的地电阻率、 电离层磁场变化的似同步异常; ② 在海地地震前夕, 电离层磁场x, z分量的能谱也出现了显著增大的现象, 类似于汶川大震前后电离层磁场的能谱增大变化.   相似文献   

11.
During flow testing of a deep, 1927-m, gravel packed screen completed well, it became apparent that well development was needed to increase productivity. A hydrojetting system using coiled tubing in combination with simultaneous pumping was developed and tested and found to be successful. To verify whether the jetting improved the well, the results of a pumping test conducted before and after the jetting operation are compared. In addition, flowmeter logging and hydraulic properties obtained from pumping tests conducted during the jetting operation were also used to verify the improvements. Hydrojetting in combination with simultaneous pumping proved to be an effective cleaning method. After 100 min of pumping, around 110 m less drawdown and 15 L/s higher average flow rate were obtained compared to the values before the jetting operation. The skin factor was positive before the jetting operation and negative thereafter, thus providing additional evidence of improvements of the well. The flowmeter data also confirmed the improvements and were valuable in optimizing the jetting operation. It was also found, from the short-term pumping tests conducted during the jetting operation, that the Hantush–Jacob method for leaky confined aquifers is a valuable indicator of the well development. The combination of methods used for the well development in this case can easily be applied on other deep well projects to obtain a controlled and time-efficient well development.  相似文献   

12.
Experiments combining different cleaning and analytical techniques indicate that multiphase magnetizations may be quite common. However, these may not be recognized because of limited experimental work. Alternating field (AF) cleaning is often the only treatment applied to igneous and metamorphic rocks; thermal and/or AF cleanings are usually the only treatments applied to sedimentary rocks. In many instances, AF and thermal treatments are limited to 100 mT and 550°C respectively. Investigations based on such limited cleaning often fail to detect some of the phases of magnetization contained in the rock. Failure to detect one or more phases means that valuable data are not recovered and the whole magnetic history of the rock has not been unfolded. Most importantly, the undetected phase might be the initial so that a secondary magnetization can easily be mistaken for the initial with an erroneous interpretation as a result. It is therefore imperative to recognize all phases of magnetizations and it possible to separate them.Procedures that have been used to recognize and unravel multiphase magnetizations are described. These procedures make use of chemical, thermal and AF cleaning treatments, two-stage demagnetization, vector analysis, slicing of specimens and vector diagrams. The combination used depends on the rock studied. For example, it is found that AF followed by thermal treatment can be very useful for the study of igneous rocks; chemical leaching is by far the most effective cleaning technique for the study of red beds. A three-phase model describing the magnetizations process of certain red beds is proposed. The slicing of specimens is used to explain intermediate directions with respect to field reversals. It is shown that graphical representation by vector diagrams can greatly facilitate the interpretation of the results. The examples show that, although a statistically well defined magnetization may be obtained after limited cleaning, it cannot be assumed to be the initial. One must ascertain that another magnetization has not remained undetected. This necessitates detailed and extensive experimental work using and devising new analytical procedures in an attempt to unfold the whole magnetic history of the rock. It is noted that tentative polar paths constructed from results obtained after inadequate experimental work cannot be up-graded by adding more data points of doubtful or unproven quality. The evolutionary process of polar paths is dependent upon increasing the reliability of palaeomagnetic results.  相似文献   

13.
SD-3A型自动测氡仪在观测中值得注意的几个问题   总被引:2,自引:0,他引:2  
论述了数字化气氡仪器SD-3A型自动测氡仪在观测中值得注意的几个问题,特别要注意①气氡观测数据在使用前要经过气温和气压的改正;②闪烁室进水、受到其他气体的污染、补充气体不及时等对观测结果影响是很明显的;③闪烁室在用空气和无水酒精清洗后测值的恢复有一个过程;④仪器标定前应用无水酒精对闪烁室进行清洗,才能提高标定的准确性.  相似文献   

14.
介绍流动重力历史资料清理流程、方法及获得的规范化成果,对1998年泾阳MS 4.8、2009年高陵MS 4.4地震前后的重力场变化进行分析,得到结论:①泾阳地震前后重力场变化满足“震前重力持续增强-震后反向恢复”的特征;②泾阳地震的发生可能与附近断裂活动有关,同时受华北块体应力场的作用;③高陵地震前后重力变化与泾阳地震前后重力变化具有一定的相似性,且位于渭河断裂附近,两个地震均受到渭河断裂活动的影响。  相似文献   

15.
曹彦波  毛振江 《中国地震》2017,33(4):613-625
2017年8月8日21时19分九寨沟发生7.0级地震,震后数小时里,大量与地震相关的信息广泛传播,互联网社交媒体高度关注,九寨沟地震成为最热议话题。本文以新浪微博为例,获取了距震中200km范围内震前、震后24h的微博数据,通过对数据清洗、分类和挖掘,分析了此次地震微博的数量、灾情分类、词频统计、时间序列和空间分布等特征,同时与实际灾评结果进行了对比分析。研究结果表明,对震后社交媒体数据进行充分挖掘,分析提取地震灾情关键信息,有助于对灾情的宏观把握,对救灾决策部署有一定的参考意义,是解决震后灾情获取难度大、覆盖小、时效性差等问题的一种有效的辅助手段。  相似文献   

16.
简要叙述了青海地区6个钻孔应变台站的观测概况,通过分析,认为主要存在观测技术系统和观测环境变化这两类干扰。在排除各类干扰后,发现只有乐都台和湟源台在汶川地震前出现了前兆异常。  相似文献   

17.
新30井新、旧观测点井水温资料初步分析   总被引:1,自引:0,他引:1  
在系统清理温泉台新30号观测井水温度20多年观测资料的基础上,归纳出新30井新、旧观测点井水温动态的多年趋势和年、月、日动态类型,并对其特征进行分析。多年动态类型为下降—阶变型和下降型,年动态类型为平稳—下降型,月动态类型为平稳—下降型和平稳—上升型,日动态类型为随机起伏型。影响水温动态类型的因素有地表水的侧向补给、邻井地下水开采及观测井内的井水扰动等,此外仪器本身的不稳定性对动态类型也产生重要影响。排除各种干扰之后,仍发现井水温度有较好的映震效应。该井水温以同震或震后效应为主,对附近的中、小地震在震前也有一定的异常显示。  相似文献   

18.
在地电清理攻关的基础上,对乌鲁木齐地电台测区的地貌、地形、水文、地质特征及介质的电学性质进行了分析,指出该台址条件有利于地电阻率的观测。同时,探讨了各种环境因素的影响。  相似文献   

19.
Cleaning with hierarchy of CO2‐based solvents is advantageous from an environmental point of view because CO2 is non‐flammable, virtually inert, and abundant. After cleaning, the only waste stuffs generated are the contaminants that are removed from the cleaned parts. The technology is especially well suited for precision cleaning applications in which parts have intricate geometries or for applications in which parts are sensitive to water or high temperature. This review will first introduce aqueous cleaning concepts and mechanism, which is helpful to understand how to design cleaning systems using high pressure CO2. Recent microelectronic processes for cleaning and rising of circuit wafers using CO2‐based solvents are the main focus of the review. Additional cleaning topics include dry cleaning, separation of dyestuffs, and extraction of contaminations from soils and regeneration of catalysts.  相似文献   

20.
为了压低干扰和有效地提取信息,本文采用Kalman滤波方法,处理了京津张唐地区17口深水井1970~1981年间的观测资料。结果表明,1976年7月28日的唐山大地震前,天津地区6口水井水位有2-3年的异常下降,下降的开始时间以3-4公里/月的速度传播。天津的6口井位于大震破裂面的西南端。大震后至今,水位无明显的异常变化,与6级以上的强余震无明显关系。北京地区的11口水井水位与大震似无明显关系。本文所采用的Kalman滤波中,每一步都采用了自回归方法和递归滤波方法计算了一步转移矩阵的元素和控制项,因而转移矩阵和控制项是随时间变化的,更适于地震前兆资料的适时处理。  相似文献   

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