腾冲地震台观测井水位同震响应特征分析

以2008—2017年腾冲地震台井水位记录的同震响应事件为研究对象,系统分析该井水位的同震响应特征,结合井孔地质背景条件,对同震响应机理进行初步探讨。结果表明:腾冲地震台井水位同震响应能力随着震级增大而逐渐增强;因井震距不同,同震响应主要表现为近震阶降—复原型和远震振荡型变化;同震响应幅度随震级增大而增大,随井震距增大而减小,且水位同震变化受震级与井震距的影响力基本相当;震级越大,同震响应持续时间越长;发生井水位同震响应的地震分布具有明显区位型特点。分析认为,振荡型同震响应机理与面波作用有关,阶降—复原型同震响应机理可能与腾冲地震台观测井所处地质构造有关。     

井水位同震响应特征与机理研究进展

大地震会在很大的范围内引起地下水响应,研究地震如何影响地下水流动的物理过程有助于认识地震和水之间的相互作用。震后井水位的变化比较直观地反映了地下水变化,而且观测的数据相对比较多。同震井水位的变化主要有3种类型：阶跃变化、持续性变化和水位随地震波的震荡。引起同震井水位变化的机制有很多,即使同样的水位变化,其对应的机制也可...     

海南琼海加积井水位对远大震的同震响应特征研究

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.     

湖南省地下流体井水位对远场大震的同震响应特征分析

通过分析湖南省地下流体观测井水位对远场大震的同震响应特征,可以得出以下结论,振荡型为湖南省井水位的主要同震响应形态,其次为阶变型和脉冲型.此外,多个观测井在同一次地震中记录到的同震响应以及多个地震在同一观测井中引起的同震响应特征均不相同.分析认为,前者可能与井况、所用仪器、构造环境、水文地质条件等因素有关,后者一方面是...     

塔院井水位和水温的同震响应特征及其机理探讨

本文统计分析了塔院井水位与水温对2004年1月至2007年9月全球68次Ms7.0以上大震的同震响应资料.分析结果显示塔院井对全球大震具有很好的映震能力,同震响应形态总是表现为水位振荡→水温下降、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不仅与震中距、震级有一定的统计关系,而且还与井-含水层特性及地震波到达时井-含水层系统的瞬时状态密切相关.综合分析了前人对水位振荡、水温下降-恢复过程的机理研究,概括为气体逸出说、热弥散说和冷水下渗说等.分析认为塔院井同震响应现象是各类机理共同作用的结果,单一的机制并不能很好地解释多次地震引起的同震响应现象.     

海南琼海加积井水位水温同步上升后转平的异常成因初探

2017年8月中旬至11月底琼海加积井水位水温同步大幅上升后至今呈转平形态的异常现象,通过开展井孔周边环境干扰的调查、井孔水体化学组分的分析、井孔构造的影响分析、周边观测井水位水温资料的对比分析以及区域构造活动的分析等工作,认为加积井水位水温的大幅上升后转平的现象非地球物理异常,推测原因应是观测段内深部含水层水补给量的增大上涌导致观测井水位水温同步上升,之后逐渐达到平衡,转而在高值的水平上呈平稳形态。而深部含水层水量补给增大的来源可能是观测井深110m以下至井底观测段内含水带揭露处井壁坍塌渗漏所致;也可能是其他的干扰所致,但具体的干扰源还有待继续核实。     

三峡井网井水位对汶川8.0级地震的同震响应特征研究h

系统分析了三峡井网8口井水位对汶川8.0级地震的同震响应及其后效特征,揭示出这些特征因井而异,其差异性在井孔结构相似的条件下主要取决于井点的构造部位、观测含水层的地下水埋藏类型、含水层的导水系数等条件;深入研究了井水位同震后效特征中残留阶升与阶降的力学含义及其地震预测意义,并用仙女山断裂带上近期地震活动验证了残留阶升区可能是未来地震危险区的科学推论．      

范县井水位对远场大震的同震响应特征

统计范县井水位对远场大震的同震响应特征,并对其响应时间、响应幅度、响应形态这3种特征进行逐一分析,探讨同震响应机理,总结规律。结果表明：观测井映震能力良好,震级越高,映震能力越好。从响应幅度来看,对M_S 6.5～7.5地震之间的同震响应具有明显优势,且大陆型地震响应表现要优于非大陆型地震;在一定条件下,震源深度对响应时间和响应幅度都有较大影响;响应形态有脉冲型、振荡型、振荡-脉冲型,非单一形态,且响应形态与震中距相关。     

陕西地区井水位对2021年玛多MS7.4地震的同震响应特征

1 研究背景大地震产生的应力能瞬间改变地壳介质状态,从而引起含水层中地下水流动以及水化学成分的变化.这些变化包括:井水位上升、下降或振荡;水温V型、U型变化或振荡;水化学成分Ca2+、Mg2+、HCO3-等离子浓度升降变化;土壤液化及泥火山活动变化,等等.     

Analysis on the Characteristics of the Coseismic Response of Water Levels Recorded in Three Wells in Hainan,China to the Two Sumatra-Andaman Strong Earthquakes

The characteristics of seismic water level fluctuations of the two Sumatra-Andaman strong earthquakes with magnitude 8.7 and 8.5 on December 26,2004 and March 29, 2005 recorded at Jiaji well, Qionghai, Hainan were analyzed, the features of the infrequent ＂step＂ changes of well water level after the two earthquakes were also analyzed and the mechanism of the ＂step change＂ of well water level was discussed. Then the high-sample-rate digital observation data of seismically-induced water level fluctuations of the Sumatra-Andaman strong earthquakes with magnitude 8.7 and 8.5 recorded at Nanbin well, Sanya and Tanniu well, Wenchang were analyzed. The results suggest that the dominant period of the seismic well water level fluctuation in all three wells was comparatively accordant, the amplitudes of seismic water level fluctuation of the same earthquake in different wells were clearly different, the time duration of seismic water level fluctuations of different earthquakes at the same well was also clearly different.     

新30井数字化水位、水温远场大震同震响应初析

收集了2007年以来新30井数字化水位、水温远场大震同震响应观测数据,总结了其同震响应特征.新30井数字化水位和水温对不同震中距强震的同震响应在一定程度上存在着一致性,水位通常为先振荡(以振荡居多)后下降,而水温则通常表现为下降.统计结果显示,新30井水位对地震的同震响应灵敏性优于同井水温观测.     

广西桂平西山井水位同震特征和机理初探

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。     

山西洪洞井水位对远场大震的响应特征分析

对洪洞井水位自2013年数字化改造以来记录到的同震响应资料进行统计分析后认为:洪洞井水位对全球MS≥7.5的远场大震有较好的响应能力,其同震响应呈一定的方向性;对不同地震的响应形态具有固定模式,以水震波为主,部分水震波伴随阶变;水位振荡阶变的初始方向以上升为主。统计分析显示,井水位同震变化幅度与震级、井震距无明显相关性,水位响应时刻与井震距有一定关系。进一步核实表明:引起水位同震响应的地震波大多为S波,部分为P波、面波;S波引起的水位变化幅度要小于P波,而面波引发的水位变化幅度最大。综合分析了前人对水位振荡的机理研究,并结合洪洞井具体情况对其相关机理进行了初步探讨。     

北京良乡、赵各庄井水位、水温同震响应对比研究

收集了2001年以来北京地区良乡、赵各庄井水位、水温的同震响应资料,从其同震响应特征中发现,虽然两观测井水位的响应灵敏度相差不大,但良乡井水温的灵敏度要好于赵各庄井。在对比两观测井水温日变化幅度以及气泡脱逸模型的基础上,结合两观测井含水层的水文地质特征,对于两观测井水温响应灵敏度的差异给出了较为合理的解释。     

Co-seismic Water Level and Temperature Responses of Some Wells to Far-Field Strong Earthquakes and Their Mechanisms

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.     

集合经验模态分解(EEMD)在地下水位数据处理中的应用初探

使用集合经验模态分解方法将水位观测数据分为高、中、低等3个频率分量。高频分量可以用来识别和研究包含同震响应在内的高频事件;中间频率分量包含固体潮的半日波、全日波信号;低频分量则反映观测数据的长期趋势性变化特征。在此基础上,将该方法应用于张道口-1井和新10井的水位观测分钟值数据,从处理后得到的高频分量中识别出31次7级以上地震的同震响应,定量地分析了其最大振幅随震中距和震级的变化特征。     

新疆北天山地区井水位同震响应特征分析研究

通过整理新疆北天山地区的水位观测资料,分析了2011年后发生在北天山地区的4次近场6级地震所引起的水位同震响应特征。结果显示,井孔对于近场地震的同震响应主要表现为振荡—阶变复合型、阶变型,同一地震对于不同的井孔可能呈现出不同的响应特征,同一井孔对于不同的近场地震也可能具有不同映震效果,水位对近场地震的同震响应并无固定的响应特征,而是受到多重因素的控制作用,而震后效应的各不一致,则显示出不同地震对于各个井孔附近区域应力场调整的能力。     

Characteristics and Mechanisms of Co-seismic Groundwater Responses in Tayuan Well

Co-seismic responses of the groundwater level and temperature in the Tayuan well of 68 earthquakes (M_S≥7.0) from January 2004 to September 2007 were analyzed. Results show that the Tayuan well has a strong ability to record large earthquakes worldwide, and the co-seismic response shows a pattern of water level oscillation → temperature decrease→ oscillation stop → temperature resumption. Further analyses indicate that the amplitude of the water level and temperature change is not only concerned with the epicenter distance and magnitude, but is also related to the temporal state of aquifer while the seismic wave arrives. Mechanisms of water level oscillation, temperature decrease, water level oscillation stop and temperature resumption are discussed, with the results from previous research on the co-seismic response mechanisms analyzed. These include gas escape, heat diffusion and cold water seepage. Results show that a single mechanism could not explain the co-seismic response of the Tayuan well water level to multiple earthquakes; the results were garnered from a variety of jointly acting mechanisms.