浅述五大连池火山区浅层气体钍、氡与断裂构造和火山活动的关系

在五大连池火山区流体化学研究原有工作的基础上，对火山群的重要区段开展了野外踏勘、气体普查，特别是用放射性气体测量方法对火烧山、老黑山、笔架山、药泉山等火山区进行了Tn、Rn测量。通过大量实测资料，分析和研究了Tn、Rn等气体和火山、火山活动、断裂构造、断裂活动性及其他地质条件的关系，初步查明了五大连池火山区的气体组成特征、分布和形成规律，对地下主要气体的成因、气体和火山构造活动及其它地质条件的关系进行了初步探讨，并提出了对五大连池火山区气体观测的初步设想和建议。     

长白山天池火山地震类型及火山活动性的初步研究

2002年以来，长白山天池火山区出现了地震活动增强、地形变加剧和多种地球化学异常等现象，火山口附近发生的多次有感地震在社会上产生了较大影响。本文利用2002年以来的流动地震观测资料，采用频谱分析、时频分析和多台站资料对比的方法，对火山区地震事件的类型进行了分析；对火山活动的危险性进行了初步研究。结果表明，目前天池火山区出现的大量地震活动仍然属于火山构造地震，少量台站地震记录中表现出的低频特征主要是由于局部介质影响造成的，排除了长周期地震引起的可能。尽管长白山天池火山地震活动明最增强，震群活动较为频繁，但仍属于岩浆活动的早期阶段，短期内发生火山喷发的危险性较小。     

腾冲新生代火山分布特征

通过实地考察和资料对比,综合前人研究成果。最终得出腾冲地区新生代火山有６８座,并给出各个火山主要分布特征。同时根据火山喷发类型、岩性、时代、地域等相关性,腾冲火山区新生代火山划分为７个火山群;１．鸦乌山－－大黑山火山群;２．大团山－－黑龙湾火山群;３．马站火山群;４．打鹰山－－马鞍山火山群;５．余家大山－大六冲火山群;６来凤山－三益村火山群;．７大呼山－－照壁山火山群。腾冲新生代火山分布肯有数量多     

土壤氡气异常特征与台湾南投7.6级地震

总结了10年来长乐筹东土壤氡气（土氡）观测点所测得的9个3．6级以上地震的土氡前兆异常特征，表明土氡异常具有预报意义。同时着重分析了1999年9月21日台湾南投Ms7.6级地震前该测点4－6月间的土氡异常特征，据此在1999年的半年度会商中提出预报意见。并介绍了7月后该测点的土氡变化特征，认为7－9月间测值的变化是由于降雨过多引起的。     

腾冲火山区地震事件(LP,VT,VE)的识别研究

利用腾冲流动数字台网资料，用多种方法对腾冲火山区的地震事件进行识别研究，认为腾冲火山区记录到的地震事件按波形主要分为两类：P波最大振幅明显大于S波及Lg波最大振幅的事件；P波最大振幅小于S波及Lg波最大振幅的事件。其中P波最大振幅明显大于S波及Lg波最大振幅的事件是火山地震的可能性较大。根据多个事件频谱随时间变化扫描图中的频谱特征，认为目前这个地区未记录到长周期事件；但流动台网记录到几组振幅较小，频率较高，振动持续时间双腾冲地震事件的持续时间（一般为6－7s)明显长，达20余秒的颤动事件，波形与Tremor事件曲型图有相似之外，这几个事件是否是Tremor事件，值得深入研究。     

长白山近代火山活动与地震

概述了长白山火山区的构造环境及其构造的活动性，以天池火山为主体的长白山火山区近代喷发的构造的活动，表现有继承与新生的构造双重性和不均衡的脉动性，区内的火山地震与区域性构造地震趋于同步活动。     

土氡测量在海口市活动断层探测中的初步应用

运用土壤氡射气(土氡)测量方法对海口市的六条隐伏断层进行探测,检验土壤氡射气(土氡)测量在海口市地区的有效性,结果表明,土氡测量探测晚更新世(Q3)和全新世(Q4)隐伏断层具有较好的效果,可以作为海口市活动断层探测一种有效手段。     

五大连池火山构造地震空间分布及其构造含义

在对五大连池地震台１９８３年以来观测到的五大连池火山区的地震记录复核的基础上，测定了火山构造地震的空间分布状态。研究结果表明该地区地震活动均为壳内地震。受火山构造环境影响，地震活动存在着外围边缘强，震源深度分布深；内部弱，震源深度分布浅的差异。火山区内部地震深度分布优势在５ｋｍ—８ｋｍ，有３个地震分布密集区，震中分布呈明显的沿火山构造断层成带分布特性。在地震条带交汇处，震源深度起伏变化大，是火山构造活动强烈部位     

我国火山灾害评估中的问题初探

文中讨论了我国火山灾害准确预报的可能性，对与火山灾害有关的一些重要问题，如高风险火山区的评估预测，火山灾害的预测评估的分期界定等进行了讨论。     

五大连池火山与冷泉

在对火山活动与温泉关系的分析基础上，讨论了五大连池区的冷泉现象，结果表明火山区的泉水温度并不是描述火山活动性的惟一指标，五大连池区的火山气体，微震活动和地热梯度等特点清楚显示了该区火山群的活动性。     

Contrasting radon background levels in volcanic settings: clues from 220Rn activity concentrations measured during long-term deformation experiments

To better understand the mechanisms leading to different radon background levels in volcanic settings, we have performed two long-term deformation experiments of 16 days using a real-time setup that enables us to monitor any variation of radon activity concentration during rock compression. Our measurements demonstrate that, in the case of highly porous volcanic rocks, the emanating power of the substrate changes as a function of the volcanic stress conditions. Constant magmatic pressures, such as those observed during dike intrusions and hydrothermal fluid injections, can result in pervasive pore collapse that is mirrored by a significant radon decrease until a constant emanation is achieved. Conversely, repeated cycles of stress due to, for example, volcano inflation/deflation cycles, cause a progressive radon increase a few days (but even weeks and months) before rupture. After rock failure, however, the formation of new emanation surfaces leads to a substantial increase of the radon signal. Our results suggest that surface deformation in tectonic and volcanic settings, such as inflation/deflation or constant magmatic pressures, have important repercussions on the emanating power of volcanic substrates.     

Radon-thoron monitoring in Tatun volcanic areas of northern Taiwan using LR-115 alpha track detector technique: Pre-calibration and installation

In the present study, experiments have been carried out to calibrate LR-115 alpha detector films in bare and cup-mode exposure for the measurement of radon and thoron concentrations in soil gas. Results showed non-uniformity in track formation on the films in bare-mode exposure. However, in cup-mode exposure the non-uniformity was reduced to a greater extent. The calibration factors obtained for radon in bare- and cup-mode exposures are 0.049 and 0.034 tr. cm^?2 per Bq m^?3 d, respectively. An attempt has been made to calibrate the radon-thoron discriminative cup with LR-115 films for simultaneous measurements of radon and thoron. This paper also presents the preliminary results of radonthoron monitoring in Tatun volcanic areas of northern Taiwan for the first time using radon-thoron discriminators with LR-115 films. The results show that the safe temperature to install the LR-115 films in volcanic areas is ≤ 65°C and thoron concentration in the study area is low.     

土壤气氡测量影响因素的初步研究

通过分析实验资料和断层气氡测量中所遇到的问题，较全面地讨论了断层气氡测量中地因素和明因素的影响。分析了断层气氡形态与断层性质的关系，以及岩土性质，土壤含水量和气温，地温，气压对土氡测量的影响。指出只要充分认识并注意避开或消除上术因素的影响就可以得到较满意的气氡测量结果。     

库尔勒断层氡气观测实验研究

根据库尔勒断层氡气在观测中遇到的一些问题,做了一系列观测实验,结果表明,氡探头的标定值的大小反映了氡探头的灵敏度,决定了测值的高低,因为地下１ｍ内的浅层气体与大气连通,所以观测值受气象因素影响较大,同时认为,在土壤相对潮湿的寒冷地区,冬季较厚的冻土层形成了良好的封闭系统,使地下氡气浓度相对增高,测值呈“冬高夏低”的变化形态,实验中还根据氡的衰变规律验证了所观测的大幅变化的测值确为氡气含量。     

Ground and indoor radon measurements in a geothermal area

Geothermally active sites compared to a relatively passive site (no geothermal activity) contain much higher radon in the soil. As expected, the maximum soil radon content is at or near the major fracture zone where hot water emanates to the surface. Thus, buildings in geothermal sites nearby or at top of cracks that facilitate hot-water transfer to the surface may be extremely dangerous in terms of high radon concentrations and this situation may pose a big threat for the inhabitants. Controlled aeration of such high-risk buildings must be carefully and continuously conducted.     

Enhancement of radon signals in geophysical studies with the track technique

The existence of a suspected geological fault has been confirmed using Solid State Nuclear Track Detectors (SSNTDs) by measuring radon concentration variations in the upper soil above its inferred position. The results obtained prompted us to increase the natural radon signal in the soil, using an additional radon source; this enhancement technique, has been experimentally checked with SSNTD detectors.On leave from Faculté des Sciences, Laboratoire des D.S.T.N. Université de Dakar, Dakar-Fann, Sénégal     

郯庐断裂带宿迁段合欢路土壤氡分布特征与迁移特征的数值模拟

沿郯庐断裂带宿迁段合欢路布设土壤氡测线并对测得的数据进行分析研究,结果表明研究区域内土壤氡探测结果对断裂带位置、断层类型和特征有较好的指示性.在已知场地地质构造参数、地层岩性特征的基础上,建立土壤氡迁移模型.建立模型时识别了断裂类型和覆盖层分层特征,并讨论了断层内部结构与氡浓度取值,使模型与实际情况相等.数值模拟结果印...     

Measurement of radon potential from soil using a special method of sampling

Soil radon gas and/or its exhalation rate are used as indicators for some applications, such as uranium exploration, indoor radon concentration, seismic activity, location of subsurface faults, etc., and also in the studies where the main interest is the field verification of radon transport models. This work proposes a versatile method for the soil radon sampling using a special manner of pumping. The soil gas is passed through a column of charcoal by using passive pumping. A plastic bottle filled with water is coupled to an activated charcoal column and the flow of water through an adjustable hole made at the bottom of bottle assures a controlled gas flow from the soil. The results obtained for the activity of activated charcoal are in the range of 20–40 kBq/m³, for a depth of approximately 0.8 m. The results obtained by this method were confirmed by simultaneous measurements using LUK 3C device for soil radon measurements. Possible applications for the estimation of radon soil potential are discussed.     

用气体地球化学方法探讨活断层的有关问题

探讨了以氡为主的断层气测量结果与断层活动性的关系;并讨论了土质、土壤、含水量、取样深度等对断层气氡测量的影响。     

Influence of Atmospheric Radon Transport on a Radon Flux from the Surface

Radon-222 is inert radioactive gas with a half-life period of 3.8 days, it is a decay product of radium-226. Being escaped from minerals and underground waters into pore space of rocks and soil, it is transported to the surface by diffusion and advection and gone to the atmosphere. When modeling processes of atmosphere radon transport one sets value of radon flux from the surface, depending on contents of radium-226 in rocks and conditions of radon transport in soil, especially on soil porosity and humidity. The impact of radon turbulent transport in the atmospheric boundary layer (ABL) on radon flux density from the surface is estimated in this paper. It is shown that both for stationary state and for typical diurnal variations of the radon volumetric activity (VA) in the ABL, the correction to the radon flux density caused by its turbulent transport in the ABL is negligible (less than 1%) and doesn’t exceed measurement errors. Thus, when calculating radon VA in the ABL it is really possible to set an average value of the radon flux density on the surface as a boundary condition.