共查询到18条相似文献，搜索用时 93 毫秒
1.
2.
3.
4.
5.
长期以来,我国的氡观测一直以模拟水氡观测为主。模拟水氡观测是地震监测预报中前兆观测的重要测项,一直采用定时取样、鼓泡、测值计算及数据入库等一系列人工观测手段。其观测方法落后,且带有较大程度的人为操作误差,使观测数据的质量受到一定程度的影响。“鼓泡”是模拟水氡观测过程的关键环节,鼓泡操作是否规范直接影响水氡测值的准确性。通过对传统模拟水氡鼓泡装置进行改造,研制出一套适用于所有模拟水氡仪器的自动鼓泡装置,解决传统人工鼓泡过程中鼓泡时间与鼓泡速率不规范对水氡测值产生较大干扰的问题。自动鼓泡装置可降低鼓泡操作难度,减少人为操作误差,提高水氡观测资料质量。 相似文献
6.
针对地下流体汞观测仪的主动采样、脱气方式,设计了满足主动脱气条件的储气装置。以储气装置气囊内气压稳定性为指标,开展储气装置匹配ATG-6138M型痕量汞在线分析仪和自然吸气鼓泡脱气装置的气汞观测实验。结果表明,储气装置能保证被测气体及时置换,维持整套气汞观测系统动态稳定,具有较好的兼容性。 相似文献
7.
8.
9.
KJD-2000R测氡仪(α谱仪)观测结果分析 总被引：1，自引：0，他引：1
通过分析KJD-2000R测氡仪(α谱仪)记录的下关温泉水中氡含量的4组α粒子能量脉冲数、氡含量以及影响观测结果因素,结合传统水氡观测仪器FD-125型室内氡钍分析器平行对比观测结果,认为:KJD-2000R测氡仪观测对象明确,而且自动鼓泡和读数,完全避免了人工鼓泡和读数引起的误差,对提高氡及其子体变化规律的认识,提高水氡观测资料质量及映震能力,充分捕获水氡前兆异常信息都具有一定实际意义,也为地震观测及台站水氡观测仪器选型提供参考。 相似文献
10.
使用姑咱海子泉气氡观测数据，分析在不同脱气—集气（溅落式和自吸式）装置下观测数据的地震前兆异常反映。溅落式脱气装置在脱气过程中无空气混入，脱气效率较低，但地震前气氡观测异常明显；自吸式脱气装置在脱气过程中有大量空气混入，脱气效率相对较高，在地震前气氡异常不明显。分析认为：①空气混入起到稀释作用，致使气氡含量降低；②脱气装置前放置恒水位槽，将地震前泉水深部自然逸出气体释放，造成异常信息减少。 相似文献
11.
对气氡脱气装置改造的几点认识 总被引：1，自引：1，他引：1
拆除了格尔木井原气氡脱气装置,针对该井冷水、大流量的实际情况,自行设计、制造了一套新的脱气装置,在其后的气氡观测中取得了良好效果,通过对改造前后氡值的分析,充分认识到了合理的脱气装置的重要性,形成了几点新的看法. 相似文献
12.
用于数字化气体观测的脱气-集气装置研制与应用 总被引：1，自引：1，他引：0
介绍用于地震地下流体台站数字化气氡、气汞等气体观测中的脱气-集气装置的研究.该装置采用流体溅射的负压脱气原理,可以有效地将自流井地下水中的气体脱析出来,在脱气过程中,可实现对装置的喷射嘴堵塞等清理的功能. 相似文献
13.
气氡观测脱气装置改造的试验研究 总被引：3，自引：1，他引：2
SD-3A自动仪器是“九五”期间中国地震局研制的自动测氡仪器,其脱气装置需要根据观测点的具体情况自行设计、制造。为此,笔者通过对武都殿沟泉脱气装置反复试验、改造,研制完成的脱气装置在武都气氡观测中获得良好效果：整点观测值的离散度明显减小,在6个月中（2002年2月至7月）有101个值超过3倍的均方差,降低到（2003年2月至7月）超过3倍的均方差的数值为零,观测值日变化幅度从几千Bq／L,降低到100Bq／L左右。。 相似文献
14.
In this paper we have developed a new method for measuring in situ soil permeability, which is based on the theory of radial gas advection through an isotropic porous medium. The method was
tested in the laboratory and at several locations on the island of Vulcano (Aeolian Islands, Italy). It consists of a special
device which generates a gas source at a depth of 50 cm and it permits measurement of the relative induced pressure in nearby
soil at different depths. The characteristic error of the method was less than 10%.
Furthermore, soil permeability measurements were carried out in the island of Vulcano during different periods of the year
(between May 2000 and June 2001). A strong decrease in permeability in the upper layers of the soil during and after rainfall
was noted, with very poor correlations between the spatial
distributions of soil CO2 flux and shallow soil permeability. 相似文献
15.
Maurizio Ripepe Andrew J. L. Harris Roberto Carniel 《Journal of Volcanology and Geothermal Research》2002,118(3-4)
During June 1999, we measured the amplitude and rate (number of events per second) at which gas exited the vent at Stromboli volcano as discrete gas bursts or puffs. This allowed us to identify two styles of gas burst (puffing) activity. The first is characterized by frequent, rapidly rising puffs, the second by less frequent, slowly rising puffs. Each style persisted over 5–40-min-long durations and was associated with a high and low number of strombolian explosions per hour, respectively. Each period was also associated with characteristic delay times between the arrival of the infrasonic and thermal signals during strombolian explosions; the delays were longer during vigorous puffing periods. To explain our observations, we propose a model in which the degassing process cycles between vigorous and weak degassing phases. During vigorous degassing phases, bubble layers ascend the conduit at a frequency of 0.5–1.0 s−1. This high degassing level reflects a gas-rich magma column and leads to an increased rate in the formation of shallow foams and, hence, an increase in puffing and explosive activity, as well as a higher free surface level and/or gas jet velocity. During weak phases, bubble layers ascend the conduit at a reduced frequency of 0.2–0.3 s−1. During such times the magma column is poor in gas. This leads to a decreased rate of foam layer formation and hence a reduction in puffing and explosive activity, as well as a lower free surface level and/or gas jet velocity. Variations in puffing activity can thus be used to track changes in the rate at which the shallow system is supplied by fresh, gas-rich magma. Our observations indicate that the two degassing styles last from 5 to 40 min and that the switch from one to the other occurs over a matter of minutes. 相似文献
16.
A. Aiuppa C. Federico S. Gurrieri M. Valenza 《Earth and Planetary Science Letters》2004,222(2):469-483
This paper deals with sulfur, chlorine and fluorine abundances in the eruptive volcanic plume of the huge October 2002-January 2003 eruption of Mount Etna, aiming at relating the relevant compositional variations observed throughout with changes in eruption dynamics and degassing mechanisms. The recurrent sampling of plume acidic volatiles by filter-pack methodology revealed that, during the study period, S/Cl and Cl/F ratios ranged from 0.1-6.8 and 0.9-5.6, respectively. Plume S/Cl ratios increased by a factor of ∼10 as volcanic activity drifted from paroxysmal lava fountaining (mid- and late November) to passive degassing and minor effusion (early January), and then decreased to the low values (S/Cl=0.1) typical of the final stages of the eruption. Parallel variations in chlorine to fluorine ratios were also observed. A theoretical model is proposed for quantitative interpretation of these changes in plume composition. The model calculates the composition of a volatile phase exsolving from an ascending Etna magma, based on knowledge of solubilities and abundances in the undegassed melt of sulfur and halogens [T.M. Gerlach, EOS 72 (1991), 249, 254-255]. According to this model, degassing of Etnean basaltic melt at high pressures and depths (>100 MPa, 3 km) is likely to release a CO2+H2O-rich vapor phase with S/Cl molar ratios ∼1. Extensive sulfur and chlorine degassing from the melt would take place at shallower depth (P<20 MPa, 0.6 km), with S/Cl ratios in the vapor phase increasing as pressure drops to 0.1 MPa. Comparisons between model compositions and volcanic plume data demonstrate that the chemical trends observed during the eruption may be explained by increased degassing due to depressurization of a basaltic magma batch ascending toward the surface. 相似文献
17.
The emission rate of carbon dioxide escaping from the summit of Kīlauea Volcano, Hawai?i, proved highly variable, averaging 4900 ± 2000 metric tons per day (t/d) in June–July 2003 during a period of summit inflation. These results were obtained by combining over 90 measurements of COSPEC-derived SO2 emission rates with synchronous CO2/SO2 ratios of the volcanic gas plume along the summit COSPEC traverse. The results are lower than the CO2 emission rate of 8500 ± 300 t/d measured by the same method in 1995–1999 during a period of long-term summit deflation [Gerlach, T.M., McGee, K.A., Elias, T., Sutton, A.J. and Doukas, M.P., 2002. Carbon dioxide emission rate of Kīlauea Volcano: Implications for primary magma and the summit reservoir. Journal of Geophysical Research-Solid Earth, 107(B9): art. no.-2189.]. Analysis of the data indicates that the emission rates of the present study likely reflect changes in the magma supply rate and residence time in the summit reservoir. It is also likely that emission rates during the inflation period were heavily influenced by SO2 pulses emitted adjacent to the COSPEC traverse, which biased CO2/SO2 ratios towards low values that may be unrepresentative of the global summit gas plume. We conclude that the SO2 pulses are consequences of summit re-inflation under way since 2003 and that CO2 emission rates remain comparable to, but more variable than, those measured prior to re-inflation. 相似文献
18.
Shingo Takeuchi Satoru Nakashima Akihiko Tomiya 《Journal of Volcanology and Geothermal Research》2008
Permeability measurement of quenched volcanic porous materials is an important approach to understand permeability development and degassing of vesicular silicic magmas. In this study, we developed a gas permeameter to measure permeability of natural samples and experimental products. The permeameter has broad measurement ranges of pressure difference (101–105 Pa) and gas-flow rate (10− 9–10− 5 m3/s). These ranges enable us to measure viscous permeability in the range of 10− 17–10− 9 m2 for 1 centimeter-scale samples, using the Forchheimer equation, which includes the inertial effect of gas flow permeating through the samples. In addition, we improved the procedure for performing permeability measurements of mm-sized products of decompression experiments. Although a previous study reported the first permeability data for vesicular silicic glass products of decompression experiments, we found an overestimation in their permeability data due to problems in sample preparation, especially for very low permeability samples. Our improved measurements give lower permeability values than those of Takeuchi et al. (2005)(Takeuchi, S., Nakashima, S., Tomiya, A., Shinohara, H., 2005. Experimental constraints on the low gas permeability of vesicular magma during decompression. Geophys. Res. Lett., 32, L10312 doi:10.1029/2005GL022491). 相似文献