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系统统计分析了云南宾川井水位与水温对印尼苏门答腊4次大震的同震响应资料。 宾川井在这4次强震中的同震响应形态表现为水位振荡—水温下降和振荡停止(减弱)—水温恢复。 进一步的分析表明, 水位与水温的变化幅度与震中距、 震级有一定的统计关系。 分别探讨了水位振荡—水温下降和振荡停止—水温恢复现象产生的机理, 综合分析了前人所提出的同震响应机理, 并依据宾川井实际观测资料对机理进行了定量化的数值模拟。 模拟结果显示, 气体逸出、 热弥散及冷水下渗作用都可以导致井水温度下降, 而水温的恢复则主要是与围岩发生静态热传导所致。 相似文献
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收集了2008~2016年广西桂平西山井水位观测数据及全球5级以上地震资料,分析井孔记录水震波的能力、水震波形态特征及影响因素,初步探讨了西山井同震的机理,获得以下认识:桂平西山井对全球M_S≥7地震具有较好的同震响应能力,水震波的形态主要为振荡型,少数呈现阶升型。井-含水层观测系统、地震震级、井震距是影响井孔记录水震波能力的主要因素。含水层介质受瑞利面波作用会发生体积变化,导致水位振荡,是形成振荡型水震波的可能机理。阶变型水震波的形成与区域应力场增强、介质变化及构造活动等因素有关。西山井水位阶升与周边中强地震活动存在较好对应关系,该认识可为地震预测研究提供参考。 相似文献
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2012年4月11日印尼苏门答腊发生8.6级、8.2级地震,我国大量地下流体台站记录到丰富的同震响应现象,甘肃地下流体观测资料也出现不同程度的同震响应。本文分析两次大地震时甘肃地区数字化水位、水温同震变化特征和响应能力,得到大部分井水位的同震响应有较一致的变化规律,且以振荡变化为主,震后较快恢复到原有状态,响应程度也与震级密切相关,即震级越大响应能力越强;由于水温和水位有不同的响应机理,因此水温不遵循这种规律,水温观测只有2个井点记录到同震响应,且记录的幅度基本相当,变化周期较大,恢复时间也较慢。 相似文献
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In this study,we analyze the co-seismic response of water levels in the Jiaji well to strong earthquakes(MS≥7.8) from 2001 to 2010 at an epicentral distance less than 8000km.We investigated the co-seismic variation form of water levels,and analyzed the relationship between the amplitude of water level variation and the magnitude and the epicentral distance.We then checked the seismic wave phases when the changes of water level occurred.It was shown that:(1) the water level’s co-seismic response is mainly characterized by escalation with no oscillation;(2) the amplitude of water level change has a certain connection with epicentral distance and magnitude;(3) co-seismic response of water levels in the Jiaji well shows a certain directivity;(4) most of the co-seismic responses were caused by surface waves,and some by long-period S waves. 相似文献
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Chen Daqing 《中国地震研究》2007,21(3):333-344
The observation of water temperature in deep wells has been carried out for more than 20 years in China.However,study on the mechanism of water temperature response to earthquakes is inadequate.During the study of the co-seismic response characteristics of water level and temperature in 121 wells within the China subsurface fluid monitoring network at the time of the December 26,2004,M-S8.7 Indonesia earthquake,we found regular response characteristics,that is,when the water level in a deep well oscillates,the water temperature in the same well will mostly experience a cycle from dropping to restoration at the same time.The process will continue for dozens of minutes to several hours.In order to confirm the observed phenomenon,we collected the digital water level and temperature observation data for 39 far-field strong earthquakes from the Tangshan well in Hebei Province(with the data set beginning in 2001).The same response characteristics were observed.Based on the analysis of the influencing factors that may cause the water temperature drop,the authors suggest the gas escape mechanism for co-seismic water temperature drop and posit two main factors that influence the water temperature drop during the process of gas escape.Finally,the authors provide a rational explanation of some observed phenomena based on the mechanism. 相似文献
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In this paper, statistics are taken on the co-seismic response of underground fluid in Yunnan to the Nepal MS8.1 earthquake, and the co-seismic response characteristics of the water level and water temperature are analyzed and summarized with the digital data. The results show that the Nepal MS8.1 earthquake had greater impact on the Yunnan region, and the macro and micro dynamics of fluids showed significant co-seismic response. The earthquake recording capacity of water level and temperature measurement is significantly higher than that of water radon and water quality to this large earthquake; the maximum amplitude and duration of co-seismic response of water level and water temperature vary greatly in different wells. The changing forms are dominated by fluctuation and step rise in water level, and a rising or falling restoration in water temperature. From the records of the main shock and the maximum strong aftershock,we can see that the greater magnitude of earthquake, the higher ratio of the occurrence of co-seismic response, and in the same well, the larger the response amplitude, as well as the longer the duration. The amplitude and duration of co-seismic response recorded by different instruments in a same well are different.Water temperature co-seismic response almost occurred in wells with water level response, indicating that the well water level and water temperature are closely related in co-seismic response, and the well water temperature seismic response was caused mainly by well water level seismic response. 相似文献
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为了掌握MS7以下强震近场流体的同震变化特征,以岷县漳县M S6.6地震为例,分析震中300 km范围内数字化水位和水温的同震变化特征及与未来4级以上地震发震区域的关系,结果显示:MS7以下强震引起的水位、水温同震相对变化幅度不大,且持续时间短,形态以突跳型变化为主;同震变化的相对幅度在空间上没有显著的差异;同震变化的初始方向在空间上具有四象限分布特征,且与震源机制解的四个区域配套;同震变化初始方向向上台站集中的区域与未来4级以上地震的发生区域有关。由于震级偏低的地震相对于MS7以上地震其发生频率高,且近场研究范围较小,因此其在未来地震的预测上具有更加重要的意义。 相似文献
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利用海口向荣村ZK46井多年水位观测资料,总结井水位正常动态变化规律、典型干扰因素及同震响应特征。结果表明：① ZK46井水位具有明显年变规律,受海潮、固体潮和气压潮复合影响;②井水位观测所受干扰主要为人为干扰,其次为观测系统和自然环境干扰,且各种干扰的表现形式不同;③对于不同地震,井水位同震响应形态、持续时间和最大震幅等各不相同,主要表现在：在形态上,大地震引起的同震响应为震荡型,中强地震引起的同震响应为固体潮畸变;震荡时间因震级和震中距不同而不同,最长196 min,最短10 min;震级越大,最大震幅越大。 相似文献
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Coseismic effects of water temperature based on digital observation from Tayuan well, Beijing 总被引：1，自引：0，他引：1
On the basis of digital records from Tayuan well,we study coseismic effects of water temperature caused by re-mote earthquakes.The records show that the water temperature changes are consistently following the process ofdrop-rise-recovery regardless of focal mechanism or epicentral directions.The step amplitude of water temperatureincreases with the increase of earthquake magnitude,and decreases with the decrease of epicentral distances.Theyhave rather well correlation.Water temperature rising after earthquake is influenced by water level variations.Fi-nally,the mechanisms of coseismic effects of water temperature have been discussed.Preliminary study shows thataccelerated convection and mixing of different temperature water in virtue of seismic wave are the main causes ofwater temperature drops.Seismic wave accelerates water convection,which causes warm water to move up fromdeeper part of the well and cold water to go down from the upper part.Temperature probe will detect water tem-perature drops at early stage.After the occurrence of earthquake,as the fluctuation of water level gradually quietsdown,water temperature near the probe begins to rise. 相似文献
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基于北京塔院井数字化水温观测资料,分析了远震引起的水温同震效应,注意到塔院井水温同震变化总是具有下降－上升－恢复的过程,不受地震方位和震源机制的影响;水温同震下降幅度随震级的增大而增大,随震中距的增大而减小, 三者之间有较好的关系;震后水温后效恢复上升幅值受水位动态影响. 最后,对塔院井水温同震效应机理进行了探讨,初步研究结果显示,井孔中的水体受震荡激发而加速对流与掺混是导致水温先下降的主要原因:当井水受到地震波的作用时,对流加速,井内深部较热的水体上涌, 而浅部较冷的水体下沉,水温探头将先观测到温度下降现象; 震后水震波逐渐平息,探头附近井水温逐步恢复上升. 相似文献
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重庆井网水位水温同震响应特征分析 总被引：1，自引：1，他引：0
本文以2008年以来全球范围内发生的5次大地震为例,对重庆井网水位和水温同震响应特征进行了分析,结合井孔水文地质条件和自身观测条件,探讨了不同同震响应现象的可能成因并对其机理进行了探讨。结果表明,水位的记震能力优于水温,水位同震响应形态主要包括上升、下降和振荡三种类型,且同一口井水位对不同地震的响应形态不同;水温的同震响应形态主要包括上升和下降两种类型,其中只有荣昌华江和北碚柳荫井水温对5次地震均有同震响应,且同一口井水温对不同地震的响应形态相同。进一步分析表明,北碚柳荫井水位的同震响应能力优于荣昌华江井水位,北碚柳荫井水位的同震振幅与地震能密度成正比,并给出了其同震变化幅度与地震能量密度的对应关系。最后分别对水位和水温同震响应机理进行了探讨。 相似文献
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收集并整理了云南地区小江断裂带附近十口流体观测井对印度尼西亚苏门答腊4次8级以上地震的响应资料．并对各观测井的记震能力及其流体测项间的响应协调性进行了统计分析。分析结果显示：物理量观测项的记震能力强于化学量观测项,水位测项的记震能力强于水温测项：小江断裂带南端各观测点的记震能力强于中部及北端各观测点：水位的同震响应形态多表现为震时振荡,而水温则多表现为震时脉冲下降。最后分析了记震协调性较好的高大、弥勒和嵩明三井的记震特征。 相似文献
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The present paper shows analysis of water level (the distance from the land surface to the water in the well under static condition) and water temperature observed at three different levels of Chuan no. 03 well to study the changes associated with the Wenchuan earthquake of 2008 and the 2011 Tohoku-Oki earthquake. Our analysis shows co-seismic changes in water level and water temperature associated with the increase in compressive stress associated with the Wenchuan earthquake. The water level shows an increase, whereas there was drop in water temperature at the shallow depth (395 m) and enhancement of water temperature at the middle (595 m) and the bottom (765 m) layers. However, no step change in water level or temperature of Chuan no. 03 well is observed associated with the Tohoku-Oki earthquake, only seismic wave propagation-induced water level oscillation and led to co-seismic response of water temperature. The analysis of the co-seismic responses and post-earthquake adjustment processes combined with the borehole histogram and the borehole temperature gradient data clearly show co-seismic changes in water temperature that could be closely associated with the changes in the regional stress and strain state and the distribution of the aquifer and the characteristics of the aquifer. The observed temperature variation of different layers in the borehole is likely to be controlled by the flow of water in the horizontal direction. 相似文献