大姚地热动态特征分析

通过大姚高精度水温观测井水地质、井孔条件的分析，震例观测资料、实验观测数据的处理，以及井水水质分析结果，表明大姚水温周期性变化的突出位置是井深75m左右，根本原因是该地层石膏脉稳定释热，含水层热水与井内冷水混合过程中，在通道内形成钙盐类沉淀物（如CaSO4CaCO3），堵塞对流通道，含水层内外压差突破被阻塞通道，热水反复侵入井内，便形成水温周期性变化。地震的孕育、发生和调整过程，由于应力场作用，产生附加地热场，水温基值发生变化，周期畸变或消失，这种附加地热动态是可以恢复的。所以认为大姚地热动态是井区特殊地层地热信息的反映。     

江苏地区数字地热正常动态及震例初步研究

地震地热前兆的观测与研究是一项具有特色的短临预报新方法,并在地震预报的实践中取得了一定的实效。江苏省地震局在“九五”期间建立了一批数字化地热综合观测台, 积累了丰富的观测资料并记录到数个地热异常震例。一年来在边观测边研究的过程中发现数字化地热观测资料具有信息量大、观测精度高、正常动态稳定、异常易于识别、映震灵敏等优点。并对数字地热资料进行了充分的使用和多种方法分析, 在研究正常动态特征和影响因素的基础上,总结异常识别和异常分析方法, 并通过对典型震例的研究探索地热异常与地震之间的关系。     

海口ZK 26井水温动态特征

通过对海口水化台ＺＫ２６井不同层位水温数字化观测资料的分析,发现水温随深度的增加呈线性上升趋势,在第二含水层的１２０～１５０m段可能有一热水活动带,而１５０m向下至１５８m段水温快速下降,并在该段观测到大致与水位反向的水温日变形态。此外,该井不同层位的水温还显示出不同的长期变化特征,并在１５３m含水层和３３６m非含水层内皆不同程度地观测到井区３００Ｋm内ＭL≥４．０级地震的可能前兆异常。     

华北地区信号震地热前兆异常特征及其预报意义的初步分析

信号震是一种广义的前震;信号震地热前兆异常和主震地热前兆异常相似;信号震和主震沿同一构造体系活动;深入研究信号震与主震地热前兆异常的关系及地热异常特征和震源机制的关系,可能对地震预报的实践有一定的指导意义。     

地热前兆预报地震的新方法研究

利用最大熵谱和带通滤波方法分析处理了北京白家疃井约6年的地热观测资料。结果表明,在频率域上有丰富的地热地震前兆信息;井—含水层系统的固有频率特性与地震活动存在一定关系。某些周期的振幅异常与200km范围内M_L≥4.0地震有较好的对应关系,特别是1989年10月18日大同M_s6.1地震前,用本方法处理地热观测资料,发现有明显的中期、短期和临震异常。 文中讨论了井—含水层系统产生响应频率特性的物质条件。     

汕头台地下流体正常动态与地震短临异常

地震前兆观测异常信息识别是前兆研究的基础.分析了汕头观测站地下流体各测项如水位、水温、气氡和气汞等观测资料,对其正常动态和短临异常信息进行了讨论.结果表明,上述各测项能够较有效地反映出某些中等地震前兆的短临异常信息.     

地下水兔出气动态特征形成机制的实验研究

通过研究管径和结构不同的井孔－含水气层物理模拟以及地下水、气补给量与逸出气动态的关系实验,得出地下水逸出气动态的最基本特征是突发、阵发,其形成机制的于逸出气运移、排放过程中存在积累－释放的往复过程。在地震等地质事件孕育、发生过程中,地壳应力、应变积累和释放可能引起的地下含水、气层的气体储存和多的场所空间及通道的变形、贯通或阻塞,地下水 流速、流量的增减及气体发生、补给量等的变化,都能在逸出气动态中     

白家疃井地热动态与地震关系初步研究

分析研究６年的地热试验观测资料的结果表明，白家疃井地热异常信息丰富，地热异常与２００ｋｍ范围内，ＭＬ≥４．０地震，有较好的对应关系；１９８９年１０月１８日大同地震前地热动态有明显的中期，短期，临震异常显示。     

定襄泉水氡正常和异常动态特征及其相互关系的研究

系统分析了定襄泉水氡的正常与异常的动态变化。 定襄水氡具有“正弓型”年变化; 依据其主要的影响因素, 一个水文年内可分出气温影响期和降水-径流影响期; 水氡还有季节性短期变化和多年周期变化。 采用“改进从属函数法”, 其定襄水氡异常与华北多次强震有明显对应关系; 前兆异常变化具有破年变、 相关关系改变及多年周期性等特点, 可作为震兆性质的动态判断标志; 正常与异常动态有着相同与不同点, 表明两者间具有一定的成因联系。     

北天山地震活动区地热信息的观测与研究

１９８９年以来，在北天山重点监视区设立了６个地热观测站（３个热水井，３个温泉），采用分辨率为０．０００１℃，精度为±０．００５℃的石英数字温度计连续记录水温的动态变化。观测结果表明：水温有两类正常动态类型，即稳定动态和年周期动态。４次中强地震前后水温出现明显的异常变化，震后变化更为剧烈。地热前兆异常形态各异，因井泉不同而不同。认为，深入研究活动断裂带和地热异常区的热信息不仅对寻找地震前兆，而且对地震危险区判定具有重要作用。     

山西断陷带地热分布的某些特征

利用山西断陷带的大地热流、地温梯度和温泉分布的资料，研究了地热分布与重力场、地壳深部构造和地震分布的关系。认为，区域性重力负异常多反映的是沉积盆地或凹陷；而在温泉附近，由于地壳深部高密度的熔融物质沿断裂上涌而形成重力正异常；在同一深度上，地壳和岩石圈薄的断陷盆地内部，其热流和温度都为高值；指出山西断陷带内的构造活动性、壳幔突变带、重磁力等值线密集带、大地热流和地温梯度高值区以及温泉密集分布带与地震活动之间都有着内在的联系。     

Geothermal gradients and heat flow in the Beaufort-Mackenzie Basin,Arctic Canada

Thermal gradients have been calculated and heat flow estimates made for 34 petroleum exploration wells along four regional profiles crossing the Mesozoic-Cenozoic Beaufort-Mackenzie Basin of northern Canada. The geothermal gradients vary from 22 mKm^–1 to 44 mKm^–1. Four sets of possible thermal conductivity values were used to calculate a range of heat flow values for each well. Generally low heat flow is observed in wells within the deeper portions of the basin and higher heat flow values occur in wells along the Aklavik Arch Complex which forms the southeastern margin of the basin.The contribution to heat flow by heat generation below the Mesozoic-Cenozoic basin fill sediments has been considered. The heat flow contribution from sub-Mesozoic sedimentary strata and underlying basement is highest along the basin-bounding Aklavik Arch Complex. The decrease in heat flow from below the basin fill sediments toward the basin depocenter may be related to basinward crustal thinning and corresponding reductions in intra-crustal radiogenic heat production.     

云南岩石圈热结构

本文探讨了云南深部热流及岩石圈地温分布的横向变化特征，并将岩石圈热结构概括为３种类型；典型现代构造活动区热结构，中间过渡型地质区热结构和稳定地质区热结构。最后，简单讨论了地热与地震活动的关系。     

水温前兆台网观测井条件研究

从水温前兆台网的现状入手,对观测井的类型、条件、传感器的观测深度及观测部位的温度特征等条件进行了分析总结,发现不同的水温正常动态类型与观测条件密切相关,并对正常动态与观测条件的关系作了初步分析,研究表明,传感器应在离开含水层和温度波动最小的层位进行观测.最后分析了水温前兆观测仪器的安装方法与观测条件,进而说明观测层位可...     

Geothermal energy prospects in Brazil: A preliminary analysis

Results of geothermal gradient measurements in 44 localities in Brazil are presented. The Precambrian shield areas are found to be characterized by relatively low temperature gradients in the range 6 to 20°C/km while younger sedimentary basins are characterized by gradients in the range 15 to 35°C/km. An inverse correlation between geothermal gradient and tectonic age has been observed. This as well as the favourable hydrological conditions suggest that the best sites for extraction of geothermal energy in Brazil are the younger sedimentary basins. The Parana Basin is found to offer at present the best site for extraction of geothermal energy in Brazil. Preliminary examination of the temperature distributions in the major aquifer (Botucatu sandstone) suggest that this aquifer contains substantial quantities of warm waters in the temperature range 40 to 90°C. The water layer in this confined aquifer is in convective motion and can be considered as a low enthalphy geothermal system. Many of the routine uses to which geothermal waters are put, such as space heating and soil warming, are not applicable in Brazil mainly because of the favourable climatic conditions. Conversion of this geothermal energy into electrical energy is also unlikely to be economical. Hence we do not consider the Parana Basin geothermal system as an independent ec9nomically exploitable energy resource. However, a few other applications are pointed out where geothermal waters can be used as a supplementary or supporting energy source in increasing the efficiency of economically viable systems utilizing hot waters.     

地热观测台网监测效能评估综合分析

地热观测台网监测效能评估是优化与完善前兆观测系统、提高在地热观测台网在防震减灾中效能的重要环节。评估内容主要包括观测环境、观测系统、观测质量和观测资料应用等方面,以省局和台站自评为基础,学科组结合日常管理对各测点进行综合分析,找出影响地热观测台网监测效能的主要因素,并相应地提出了合理解决方案。     

Geophysical greenfield exploration in the permo‐carboniferous Saar–Nahe basin—The Wiesbaden Geothermal Project,Germany

Structurally bound upwelling and outflowing hot fluids in the city of Wiesbaden suggest an interesting geothermal potential at the northern margin of the permo‐carboniferous Saar–Nahe basin, Germany. The Saar–Nahe basin in the Wiesbaden area was previously not a target for intensive geophysical prospecting of the deep underground. We present an exploration concept to investigate potential geothermal reservoirs near Wiesbaden for heat and power production. The acquired geophysical exploration data give new insights into the local geometry and internal structure of the Saar–Nahe basin. The exploration combines a wide range of methods, including the analysis of data, a dense grid gravity survey, as well as two‐dimensional and three‐dimensional seismic surveys. The resulting data, which for the first time reveal the deep structure of the Mainz and Saar–Nahe basins near Wiesbaden down to a depth of c. 4,000 m, show that the Saar–Nahe basin is strongly segmented and contains deep‐reaching active faults. Combining these information with numerical models of the stresses in the fault system and of the temperature distribution in the exploration area, a promising drilling target has been identified, which promise high permeability at a low risk of induced or triggered seismicity.     

Geothermal observations in east Liaoning and haicheng seismic area

We have obtained altogether heat flux data of 23 drill holes including 2 observational holes of thermal flow in the Haicheng seismic area. These data show roughly thermal structure of the crust in eastern Liaoning and in the Haicheng seismic area. The results indicate that there is higher value of heat flow in the belt north by east from Liaoyang to Xiongyue, the average thermal flux being 8.29× 10⁻²J/m²·s (2.0 hfu). The average thermal fulx in the Haicheng seismic area is 9.22×10²J/m²·s (2.2 hfu). Comparing with other known geophysical data of the Haicheng seismic area, we give a geophysical section of comprehensive interpretation. We suppose the low-velocity layer in the lower crust of the Haicheng seismic area is a result from intrusion of large-scale uper mantle substance. High temperature and low velocity mean that the layer has the nature of plastic mechanics. The focal region of the Haicheng earthquake is situated right in the upper part of that plastic layer. Obviously, this result is significant for studying the seismogenic process of the Haicheng earthquake and other intra-plate earthquakes. We attempt to emphasize that observation of heat flow is necessary for earthquake study. Gu Haoding did the actual writing.