共查询到18条相似文献，搜索用时 140 毫秒
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以芦山、汶川地震震中为中心,选择了8个井点,对2个地震引起的井水位同震变化进行了比较,重点分析了3口同震变化反向的井点,即重庆的荣昌华江井、北碚柳荫井和四川的泸沽湖井。为使对比研究结果可靠,进一步收集了2011年3月11日日本9.0级地震、2012年4月11日苏门答腊北部海域8.6级地震引起的井水位同震变化资料。对汶川、芦山地震引起的同震体应变的计算结果显示：汶川地震时,荣昌华江井、北碚柳荫井和泸沽湖井水位同震变化与井点位置处的同震体应变一致,即位于同震体应变压缩区的井水位上升,位于体应变膨胀区的井水位下降;芦山地震时,3口井的水位同震变化与同震体应变不一致,表现出与日本、苏门答腊地震时相似的同震变化特征。 相似文献
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地震地下流体已成为一种重要的地震监测手段。 本文分析夏垫断裂带上观测井的同震响应特征, 探讨观测井水位、 水温同震变化对夏垫断裂带的影响机理, 收集和整理布设在夏垫断裂带上的赵各庄井和西集井两口观测井水位和水温同震响应资料, 从响应的地震次数及发震位置、 异常幅度、 时间和形态类型等方面对其响应特征进行分析, 从震中距、 震级和井-含水层岩性等方面探讨了地下流体地震前兆异常的成因。 结果显示, 赵各庄井和西集井水位地震响应能力强于水温, 响应形态以振荡型为主, 对于MS7.0以上地震具有显著的映震能力。 在水温资料中, 仅有赵各庄井对2008年汶川MS8.0地震有响应, 响应幅度为0.0129℃。 综合分析认为, 井-含水层岩性影响了两井同震响应形态特征, 远场大地震产生的动态应变导致了较大的水位变幅。 相似文献
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2004年12月26日印尼8．7级和2007年9月12日印尼8．5级地震不同程度引起新疆地下流体和形变的同震效应。震后,水位首先出现同震水震波,而后出现大幅度上升现象;水温出现震时脉冲突升,震后小幅度下降,然后逐步过渡到一个新的稳定状态。两次印尼8级地震,前者较后者水温和水位同震波到时短、波幅大、振荡持续时间长。重力仪记录到变化幅度极大、到时和结束时相当清晰的同震震波,且初始到时在其他形变记录仪器之前,持续时间较长;倾斜和应变记录到同震阶跃,但持续时间相对较短。垂直摆正常波动时有明显的固体潮,地震波到时后固体潮畸形变化或消失,地震波基本衰减完后,重新出现明显固体潮。 相似文献
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黄骅井水位对苏门答腊5次地震的同震响应初步研究 总被引：3，自引：2，他引：1
利用ARX模型分析了河北省黄骅井水位对气压和固体潮的响应特征,并利用该模型消除气压和固体潮对该井水位的影响,准确地提取了5次苏门答腊大震引起的同震水位变化异常.分析了该井水位对这5次地震的同震响应模式与震级和震源机制解的关系,初步探讨了引起该井水位同震变化复杂性的可能原因.认为,即使发生在同一地区,震源机制解基本相同的地震也会引起远距离同一井水位不同的响应特征,其响应幅度与发震震级有关,响应方式可能与井孔所处地区的局部应力应变状态或井-含水层系统的结构变化有关. 相似文献
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基于全国地下流体前兆台网数据库的统计,本文了整理中国大陆井水位观测网中对甘肃岷县漳县6.6级地震水位同震响应的台站特征.分析结果是：（1）岷县漳县6.6级地震烈度Ⅵ度区的1.5倍的范围内主要由静态应变引起的水位同震变化仅有一个台站,水位同震阶升幅度仅1.5 cm,静态应变触发地震的可能性不大;（2）震中距大于1 000 km的远震响应均为水位阶升,但是其同震变化幅度小于0.3 cm,为含水层被压缩引起;（3）该地震引起的水位同震变化的观测井较少,分布范围大,整体上以水位同震阶升占据主体,其分布主要在静态应力变化引起的范围之外,并且与构造带的对应关系无规律可循,此次地震静态应变范围内的应力应该已经得到释放. 相似文献
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井水位固体潮加卸载响应比的地震短临前兆 总被引：9，自引：0，他引：9
从岩石的应变与应力的非线性响应分析了井水位固体潮加卸载响应比的物理机理，分析了承压井含水层对固体潮体应变的响应，给出了计算井水位固体潮加卸载响应比的两种方法，并以距菏泽5.9级地震震中较近的豫01井为例，计算了该井水位对固体潮体应变的响应率和两种固体潮加卸载响应比．震前响应率和响应比都有增大的变化． 相似文献
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为提升对山西省地下流体观测井承压性的进一步认识,以位于该省北、中、南部的朔州井、静乐井、祁县井、洪洞井和东郭井为研究对象,选取水位、气压观测数据,并利用井水位的理论固体潮数据,分别对井水位进行气压的阶跃响应函数计算、FFT频谱和潮汐相位响应分析,综合判定地下流体观测井—含水层类型,结果表明,5口观测井地下水埋藏类型均为半承压水。 相似文献
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The large scales of co-seismic water level changes in mainland China were observed in response to the tragic 2008 Ms 8.0 Wenchuan earthquake. To better understand the mechanism of these hydrogeological phenomena, groundwater-level data at 17 confined wells, with an epicentral distance of <500 km, were collected. We compare the static strain predicted by dislocation theory with the volumetric strain calculated by the tide effect of the groundwater based on poroelastic theory. The results show that the sign of the co-seismic groundwater level change is consistent with the sign predicted by dislocation theory. Additionally, the magnitude of the strain calculated by the two methods is also concordant in half of the wells. In the rest of the wells, the strains inversed from the groundwater level are one or two orders of magnitude larger than the fault dislocation model. These wells mostly have an epicenter distance larger than 300 km; therefore, the dynamic stress induced by the seismic wave may be responsible for the co-seismic water level changes in these wells. According to these results, we roughly estimate that the effect range of the static stress is approximately 300 km for the Wenchuan earthquake, and the dynamic stresses dominate beyond this epicenter distance. In addition, geological and hydrogeological conditions and other mechanisms may be responsible for these changes. 相似文献
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This work focuses on variations of the Earth tidal factor and phase lag derived from groundwater observations before and after major earthquakes. It is based on an analysis of the data from four observational wells at boundaries between distinct active blocks of China mainland. These wells are also situated on several active fault zones and have exhibited considerable responses to the Wenchuan M s8.0 earthquake of 2008 in China. We collected hourly records of water levels of these wells from 2007 to 2009 and processed these data for analysis. The tidal factors, phase lags, and phase-difference changes of tidal residuals of each well were calculated. We found that when the Wenchuan quake happened, the tidal factors of the 4 wells were changing rapidly, while their phase lags and phase differences of tidal residuals declined swiftly, which may reflect the stress and strain changes of the well-aquifer system during the seismic generation. 相似文献
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利用水位、 气压和理论固体潮数据, 采用卷积回归法中水位对气压的阶跃响应函数， 定量地分析和判定了华北北部板桥井、 大灰厂井、 黄骅井、 大甸子井、 丰镇井和三号地井的井-含水层系统的地下水类型， 并结合研究时段内各井的气压系数和M2波潮汐因子的结果进行了对比分析． 结果表明: ① 各井的滞后时间与阶跃响应函数之间存在明显的以e为底的指数函数关系， 且底数e的系数的正负决定了井-含水层系统的地下水类型； ② 承压井的阶跃响应函数随滞后时间的增大而增大， 且最佳阶跃响应函数值越大， 相应的气压系数和M2波潮汐因子也越大， 反之亦然； ③ 潜水井和半承压水井的阶跃响应函数随滞后时间的增大而减小， 其最佳阶跃响应函数与气压系数和M2波潮汐因子间的关系不明显， 可能与含水层的水力特性、 井孔结构及固体潮汐波的频率有关． 相似文献
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系统分析了三峡井网 8口井水位、4口井水温和 4个井台土氡 2 0 0 1年的观测数据 ,建立了各个测项的正常动态 ,并检验了其各自的映震能力。结果表明 ,8口井水位均有固体潮显示 ,其对地壳体应变的响应灵敏度为 10 - 9～ 10 - 10 体应变 /mm。井水位大多有气压效应 ,并受一定程度的降雨干扰。 4口井的水温动态相对平稳 ,日变幅一般为千分之几度。 4个井台的土氡动态起伏较大 ,变化范围在几到几十Bq/L之间。在 2 0 0 1年 10月 16日秭归县梅家河ML3 6地震前 ,有 6口井水位、1口井水温和 1个井台的土氡有异常显示 ,表明三峡井网具有较强的映震能力 相似文献
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The Dogo hot spring, situated in Matsuyama City, Ehime Prefecture, Japan, is one of the oldest and most famous hot springs
in Japan. The groundwater level or discharge at the spring decreased four times during the past eight or nine Nankai earthquakes.
These are large interplate earthquakes that have occurred repeatedly in the western part of the Nankai Trough at intervals
of 100–200 years since A.D. 684. To clarify the mechanism of these earthquake-related changes in the water level at the spring,
we analyzed groundwater-level data recorded at the spring immediately after the 1946 Nankai earthquake and over the period
from 1985 to 2006. We detected the other nine postseismic increases in groundwater level and no decreases, except for a large
decrease of 11.4 m related to the 1946 Nankai earthquake. The increases were probably caused by ground-shaking, while the
decrease was caused by a change in coseismic volumetric strain. These results lead to the following explanation of the recorded
earthquake-related changes in the groundwater level at the Dogo hot spring. Both coseismic changes in volumetric strain and
ground-shaking can lead to postseismic changes in groundwater pressure. The increase in groundwater pressure arising from
ground-shaking is generally greater than the change in pressure associated with changes in coseismic volumetric strain; however,
at the time of the Nankai earthquakes, the spring experiences a large increase in coseismic volumetric strain, leading to
a considerably larger decrease in the groundwater level than the increase associated with ground-shaking. Therefore, the groundwater
level at the Dogo hot spring usually increases at times of relatively large earthquakes, although the groundwater level or
discharge decreases in the case of the Nankai earthquakes. 相似文献
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The seismic waves excited by the M
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7.6 Olyutorskii earthquake that occurred on April 20, 2006 in the Koryak Upland gave rise to water-level changes in five
wells situated in continental areas of Kamchatka at hypocentral distances of 750–1150 km. We describe the effects due to seismic
waves, as well as the water-level anomalies for February–April 2006 before the earthquake. We used an original technique for
the processing of water-level records based on the study of barometric and tidal water-level responses in order to estimate
the volume strain in water-saturated rocks during synchronous level variations at two wells. We discuss possible mechanisms
for producing anomalous water-level changes due to elastic deformation of monitored groundwater reservoirs and to crack dilatancy
in the water-saturated rocks. 相似文献