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Journal ArticleDOI

Variations of soil radon and thoron concentrations in a fault zone and prospective earthquakes in SW Taiwan

TL;DR: In this article, an automatic station for soil gas monitoring was set up on an active fault zone of SW Taiwan, and some spike-like anomalous high radon and thoron concentrations could be observed.
About: This article is published in Radiation Measurements.The article was published on 2005-11-01. It has received 135 citations till now. The article focuses on the topics: Soil gas & Radon.
Citations
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Journal ArticleDOI
TL;DR: In this paper, a brief review of the progress made in the field of radon measurements in earth sciences, specially in predicting earthquakes, is presented, and the models proposed in relating precursor time, epicentral distance, magnitude of earthquake have also been discussed.

169 citations

Journal ArticleDOI
TL;DR: In this paper, Radon monitoring was carried out using emanometry technique at Palampur and Dalhousie stations in the Kangra valley of Himachal Pradesh (India) from June 1996 to September 1999.
Abstract: Many theoretical and empirical algorithms have been proposed in the literature for radon release; however whilst its relation with earthquake occurrence has been developed on occasions, there have been no specific complete studies of this phenomenon. In this study, radon monitoring was carried out using emanometry technique at Palampur and Dalhousie stations in the Kangra valley of Himachal Pradesh (India) from June 1996 to September 1999. Discrete radon concentrations were recorded in soil-gas and groundwater at both the stations. Radon anomalies were correlated with microseismic events recorded along the Main Boundary Thrust (MBT) of N-W Himalaya in the grid (30-34°N, 74-78°E). The influence of meteorological parameters viz, temperature, rainfall, relative humidity and wind velocity on radon concentration was qualitatively evaluated. The radon exhalation showed positive correlation with temperature, rainfall, relative humidity and negative correlation with wind velocity. Both positive and negative radon anomalies were recorded. The study reveals the precursory nature of radon anomalies and their correlation with microseismic events in 62% of the cases but prediction of earthquakes is yet a remote possibility. From the analysis it has been found that radon anomaly is not only influenced by seismic parameters but also by meteorological parameters and the nature of carrier gases/fluids. To learn more about the phenomenon, simultaneous recording of various gases (He, CO2, CH4) and meteorological parameters, together with multiple continuous measurements of radon have been suggested.

107 citations


Cites background from "Variations of soil radon and thoron..."

  • ...…an earthquake (Talwani et al. 1980; Mogro-Campero et al. 1980; Fleischer 1981; Liu et al. 1984/85; Virk 1986, 1993, 1997; Segovia et al. 1989; King et al. 1993; Virk and Singh 1992; Igarashi et al. 1995; Heinicke et al. 1995; Virk et al. 1997; Singh et al. 1999; Chyi et al. 2005; Yang et al. 2005)....

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  • ...Radon observations, both in soil-gas and in groundwater, revealed many precursory changes in its concentration before an earthquake (Talwani et al. 1980; Mogro-Campero et al. 1980; Fleischer 1981; Liu et al. 1984/85; Virk 1986, 1993, 1997; Segovia et al. 1989; King et al. 1993; Virk and Singh 1992; Igarashi et al. 1995; Heinicke et al. 1995; Virk et al. 1997; Singh et al. 1999; Chyi et al. 2005; Yang et al. 2005)....

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Journal ArticleDOI
TL;DR: In this paper, soil gas compositions are measured and synthesized in conjunction with the geological, geophysical and geomorphological information along the Chaochou Fault, which is considered as an active fault in southern Taiwan.
Abstract: The soil-gas method is based on the principle that faults and/or fractures are highly permeable pathways in rock formation where gases can migrate upward from the deep crust and/or mantle and retain their deep-source signatures in the soil cover. This method is adopted because it can give results in short time and at low costs. In this work, soil-gas compositions are measured and synthesized in conjunction with the geological, geophysical and geomorphological information along the Chaochou Fault, which is considered as an active fault in southern Taiwan. More than 500 soil-gas samples were collected along 18 traverses crossing the observed structures and analyzed for He, CO 2 , CH 4 , O 2 + Ar and N 2 . The results show that both helium and carbon dioxide concentrations in the soil gas have anomalous values at the specific positions in each of the traverses. The trace of these positions coincides with the N-S trending faults and/or fractures, that is, the postulated trend and pattern of the faults in southern Taiwan. Hence, helium and carbon dioxide are useful index gases in this area. Based on the helium and carbon dioxide concentrations of the soil gases, at least three components are required to explain the observed variations. In addition to the atmospheric air component, two gas sources can be recognized. One is the deep crust component, exhibiting high He and CO 2 concentrations, and considered as best indicator for the surface location of fault/fracture zones in the region. The other component could be a shallower gas source with high CO2 concentration, and low He concentration. Moreover, helium isotopic compositions of representative samples vary from 0.52 to 1.05 Ra (the 3 He/ 4 He ratio of air), illustrating that most samples have soil air component and may be mixed with some crustal component but no significant input of mantle component. Carbon isotopic composition (δ 13 C) of carbon dioxide in the soil samples vary from ‐11.8 to ‐23.4‰, which could be the result of mixing of organic and limestone components. Both helium and carbon isotopic results support the multiple gas sources in studied area. Meanwhile, continuous monitoring indicates that soil gas variations at fault zone may be closely related to the local crustal stress and hence, is suitable for further monitoring on fault activities.

97 citations


Cites background or methods from "Variations of soil radon and thoron..."

  • ...…1976; Butt and Gole, 1986; Gole et al., 1986), geothermal reservoirs (e.g., Roberts et al., 1975; Hinkle, 1978; Corazza et al., 1993), and earthquake prediction (e.g., King, 1980; Virk and Singh, 1993; Al-Hilal and Mouty, 1994, Chyi et al., 2002, 2005; Walia et al., 2005b; Yang et al., 2005b), etc....

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  • ...The sample bottle, which is made of potassium glass to preserve helium gas from escaping by diffusion, is used for further helium isotope analysis (Yang et al., 2005a)....

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  • ...…the measured ratio, including the analytical errors of the sam- 430 C.-C. Fu et al. Reconnaissance of soil gas composition over the buried fault and fracture zone in southern Taiwan 431 ple and the working standard gas, and long-term variations of standard, was less than 2.5% (Yang et al., 2005a)....

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Journal ArticleDOI
TL;DR: In this article, the authors investigated the possible connection between eventual radon/helium anomalies and active faults and found that radon and helium together can act as a powerful tool for the detection and mapping of active fault zones.

91 citations


Cites methods from "Variations of soil radon and thoron..."

  • ..., 1999) and commonly used as precursors for earthquake prediction studies (e.g., Virk et al., 2001; Yang et al., 2005)....

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Journal ArticleDOI
TL;DR: In this article, the Istituto Nazionale di Geofisica e Vulcanologia (S.G., M.W.N) and the Dipartimento della Protezione Civile (Italy), projects V3_6/28-Etna======676(M.W., S.G.), and NSF======676EAR 063824101 (K.S.).
Abstract: This work was funded by the Istituto Nazionale di Geofisica e Vulcanologia (S.G., M.N.) and by the Dipartimento per la Protezione Civile (Italy), projects V3_6/28-Etna (M.N.) and V5/08-Diffuse degassing in Italy (S.G.), and NSF EAR 063824101 (K.W.W.S.).

86 citations


Cites background from "Variations of soil radon and thoron..."

  • ...Similar high ((220)Rn) emissions relative to (222)Rn have been observed in other seismically active areas and have also been explained as microfracturing of shallow rock weeks to months before moderate earthquakes [Yang et al., 2005]....

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  • ...Similar high (220Rn) emissions relative to 222Rn have been observed in other seismically active areas and have also been explained as microfracturing of shallow rock weeks to months before moderate earthquakes [Yang et al., 2005]....

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  • ...The former is a typical correlation found in volcanic and geothermal areas [e.g., Chiodini et al., 2005], whereas the latter has previously been observed in other active geodynamical contexts [e.g., Yang et al., 2005]....

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References
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Journal ArticleDOI
TL;DR: In this article, the main sources, behaviours and uses of species detected in soils and springs are displayed, and their mode of sampling and analysing briefly described, and the main patterns of degassing in soils are described and a wide range of geochemical signatures as the result of both permeability and mineralogical contrasts.

420 citations

Journal ArticleDOI
07 Jul 1995-Science
TL;DR: Radon concentration in ground water increased for several months before the 1995 southern Hyogo Prefecture (Kobe) earthquake on 17 January 1995, and reached a peak of more than 10 times that at the beginning of the observation, before starting to decrease.
Abstract: Radon concentration in ground water increased for several months before the 1995 southern Hyogo Prefecture (Kobe) earthquake on 17 January 1995. From late October 1994, the beginning of the observation, to the end of December 1994, radon concentration increased about fourfold. On 8 January, 9 days before the earthquake, the radon concentration reached a peak of more than 10 times that at the beginning of the observation, before starting to decrease. These radon changes are likely to be precursory phenomena of the disastrous earthquake.

404 citations

Journal ArticleDOI
TL;DR: In this paper, the authors studied the anomalous high concentrations of radon, helium, hydrogen, mercury, carbon dioxide, and several other volatiles along active faults, suggesting that the faults may be paths of least resistance for the terrestrial gases generated or stored in the earth to escape to the atmosphere.
Abstract: Terrestrial gases in groundwater and soil air have been extensively studied in recent years in seismically active areas, especially in USSR, China, Japan, and United States, in search of premonitory changes that might be useful for earthquake prediction. Concentrations of radon, helium, hydrogen, mercury, carbon dioxide, and several other volatiles have been found generally to be anomalously high along active faults, suggesting that the faults may be paths of least resistance for the terrestrial gases generated or stored in the earth to escape to the atmosphere. Temporal gas concentration changes with durations of a few hours to many months have been observed before many large earthquakes at a relatively small number of favorably situated stations at epicentral distances of up to several hundreds of kilometers. These “sensitive” stations are generally located along active faults, especially at intersections or bends of faults, or some other structurally weak zones, possibly because of tectonic strain concentration at such places. However, gas concentrations, especially those measured at or near the ground surface, may also be significantly affected by meteorological, hydrological, and other nontectonic changes in the environment. The nontectonically induced variations must be carefully eliminated or recognized in the search of true earthquake-related anomalies.

293 citations

Journal ArticleDOI
TL;DR: A wealth of fundamental information regarding the Earth and solar system is based upon observations of the highly volatile elements He, Ne, Ar, Kr, and Xe as discussed by the authors, which are known collectively as the rare gases, reflecting their general scarcity in geological materials.
Abstract: A wealth of fundamental information regarding the Earth and solar system is based upon observations of the highly volatile elements He, Ne, Ar, Kr, and Xe. At first, this may seem surprising, considering that these elements are generally thought to reside almost entirely in the atmosphere, and so are considered strongly ‘atmophile.’ However, increasingly sophisticated analytical techniques have provided the means for precisely measuring their abundances in a wide range of geological and cosmochemical materials. Fittingly, these elements are known collectively as the rare gases, reflecting their general scarcity in geological materials. It is this feature that continues to provide challenges for analysts. These elements are also the noble gases, in tribute to their disdain for engaging in chemical consort with other species. Such behavior has been responsible for the early difficulties in their detection, and facilitates their continuing migration to the atmosphere. However, others refer to these as ‘the inert gases,’ which seems to imply that their behavior is dictated by a lack of interest in chemical reaction, a deficiency in chemical drive. Overall, the choice of appellation depends upon whether scarcity, nobility, or inertness is considered the most important characteristic. Regardless of their motivations, these noble gases can be profitably considered together, because physical and chemical properties vary systematically with atomic weight. However, much of the utility of noble gases is based on the widespread variations in their isotopic compositions. This is related to their overall depletion, which has made these elements vulnerable to isotopic modification from nuclear processes involving relatively more abundant parent elements. The wide applicability of noble gas systematics is due to the range of such processes. In cosmochemistry, fundamental contributions have been made to understanding the sources and distributions of volatiles throughout the solar system, to identifying the preservation of nucleosynthetic anomalies in meteorites, …

135 citations