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31.
32.
The recent development of the Lithosphere–Atmosphere–Ionosphere (LAI) coupling model and experimental data of remote sensing satellites on thermal anomalies before major strong earthquakes have demonstrated that radon emanations in the area of earthquake preparation can produce variations of the air temperature and relative humidity. Specific repeating pattern of humidity and air temperature variations was revealed as a result of analysis of the meteorological data for several tens of strong earthquakes all over the world. The main physical process responsible for the observed variations is the latent heat release due to water vapor condensation on ions produced as a result of air ionization by energetic α-particles emitted by 222Rn. The high effectiveness of this process was proved by the laboratory and field experiments; hence the specific variations of air humidity and temperature can be used as indicator of radon variations before earthquakes.We analyzed the historical meteorological data all over the Mexico around the time of one of the most destructive earthquakes (Michoacan earthquake M8.1) that affected the Mexico City on September 19, 1985. Several distinct zones of specific variations of the air temperature and relative humidity were revealed that may indicate the different character of radon variations in different parts of Mexico before the Michoacan earthquake. The most interesting result on the specific variations of atmosphere parameters was obtained at Baja California region close to the border of Cocos and Rivera tectonic plates. This result demonstrates the possibility of the increased radon variations not only in the vicinity of the earthquake source but also at the border of interacting tectonic plates. Recent results on Thermal InfraRed (TIR) anomalies registered by Meteosat 5 before the Gujarat earthquake M7.9 on 26 of January 2001 supports the idea on the possibility of thermal effects at the border of interacting tectonic plates. 相似文献
33.
A field instrument designed for continuous radon measurement is described. It is based on a solid state electronic sensor that is housed in a rugged casing that also contains its associated electronics. This lightweight device is designed for selective counting of
α-decays with recorded count values over specified intervals being stored within the device. Real time data processing to reject spurious values is automatically performed by the instrument. Data are downloaded by means of a handheld or a laptop computer. The energy provided by alkaline batteries ensures 2 months of continuous recording in the field. Example of radon anomalies are exhibited. 相似文献
34.
库尔勒断层氡气观测及观测资料分析初探 总被引:1,自引:1,他引:0
简要介绍了库尔勒断层氡气测孔周围的地质构造条件及仪器设置,并对两年多的观测资料进行分析。认为A道较好地记录到1995年3月19日和硕Ms5.1级地震及5月2日乌苏Ms5.8级地震前的突跳异常;同时利用B道氡资料与气温,气压作了多元回归分析,认为B道连续两年多出现的长时间,大幅度变化的异常现象主要是受气温,气压季节性变化的影响。 相似文献
35.
水氡观测作为地震活动的一种前兆观测项目,由于受地下水动力条件的影响,会出现不稳定的因素。通过对潜水不完整井氡值变化规律的研究,运用地下水动力学原理,得出潜水不完整井在达到动态平衡状态时取样,可保持氡含量的相对稳定的结论。 相似文献
36.
在多年工作的基础上,介绍了水氡仪器的标定方法,分析了水氡仪器常见故障的原因及判别、排除方法等,指出所介绍的方法可供仪器标定人员工作时参考。 相似文献
37.
使用40个地下流体观测点的资料,对1990年4月26日青海省共和MS7.0地震的前兆动态特征进行了系统研究.结果表明:(1)地震带内观测点的水氡趋势异常及水化、水位群体异常及频次异常与断层平均形变速率呈同步变化.地下流体群体异常频次的累加值曲线在地震前表现为指数加速变化图形.(2)震源外围240km范围内的水氡中短期趋势上升异常,表现为由震源逐渐向外围扩散的特点.在短临阶段各测点水氡的异常变化基本同步.(3)流体短临前兆出现明显的起伏加剧和层次现象,突出的表现是流量、断层气日变化在临震阶段出现3次加剧,且异常幅度一次高于一次. 相似文献
38.
The authors conducted a Rn222 survey in wells of the Larderello geothermal field (Italy) and observed considerable variations in concentrations. Simple models show that flow-rate plays an important part in the Rn222 content of each well, as it directly affects the fluid transit time in the reservoirs. Rn222 has been sampled from two wells of the Serrazzano area during flow-rate drawdown tests. The apparent volume of the steam reservoir of each of these two wells has been estimated from the Rn222 concentration versus flow-rate curves.List of symbols
Q
Flow-rate (kg h–1)
-
Decay constant of Rn222 (=7.553×10–3 h–1)
-
Porosity of the reservoir (volume of fluid/volume of rock)
- 1
Density of the fluid in the reservoir (kg m–3)
- 2
Density of the rock in the reservoir (kg m–3)
-
M
Stationary mass of fluid filling the reservoir (kg).
-
E
Emanating power of the rock in the reservoir (nCi kg
rock
–1
h–1).
-
P
Production rate of Rn222 in the reservoir: number of atoms of Rn222 (divided by 1.764×107) transferred by the rock to the mass unit of fluid per unit time (nCi kg
fluid
–1
h–1).
-
N
Specific concentration of Rn222 in the fluid (nCi kg–1)
-
Characteristic time of the steam reservoir at maximum flow-rate (=M/Q) 相似文献
39.
40.
A 3-year study of indoor radon in more than 1000 homes in northern Virginia and southern Maryland was conducted using 3-month
exposure alpha-track monitors. In a study set of 200 homes, first-floor indoor radon concentrations, which most closely approximates
home exposure levels, averaged slightly more than 3 pCi/l. In a study set of 100 homes, sub-slab ventilation was used to reduce
indoor radon concentrations. Interest in remediation was related to public perception of the hazardous nature of radon; people
living in homes with indoor radon measurements of more than 4 pCi/l were more likely to participate in the remediation phase
of the project. Sub-slab ventilation was successful in more than 90% of the homes in reducing indoor radon from concentrations
as high as 30 pCi/ to less than 4 pCi/l, at least for the entire year of post-remediation radon measurements.
Received: 29 February 1996 · Accepted: 29 May 1996 相似文献