Groundwater radon anomalies associated with earthquakes

Igarashi, George; Wakita, Hiroshi

doi:10.1016/0040-1951(90)90311-u

Cited by 112 publications

(85 citation statements)

References 16 publications

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“…d) water temperature and (e) radon concentration. The data were taken at the KSM station, northeast Japan (Igarashi and Wakita, 1990). Radon concentrations are expressed as cpm (count per minute).…”

Section: Stochastic Differential Equationsmentioning

confidence: 99%

“…Recently, reports on earthquake-related changes in groundwater radon, including preseismic and coseismic, have increased (e.g., Wakita et al, 1989Wakita et al, , 1991Igarashi and Wakita, 1990;Igarashi et al, 1993). It is now certain that the correlation between groundwater radon changes and earthquake occurrences is statistically significant.…”

Section: Introductionmentioning

confidence: 99%

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Time Series Analysis of Groundwater Radon Using Stochastic Differential Equations.

et al. 1995

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This paper provides a new approach to detect changes in the groundwater radon concentration related to an earthquake. We express changes in radon concentration in a radon-detection chamber by using stochastic linear differential equations. These equations are represented by the state space notation, and then its solution is replaced by an estimation of the state vector at discrete points in time with an assumption that the coefficients describing the stochastic differential equations are constant for a sufficiently small time interval. Since the solubility of radon in water depends strongly on temperature, the separation of radon from liquid water, which is necessary for radon detection, causes fluctuations in the observed radon concentrations due to water temperature changes in the chamber. We applied our procedure to some actual data sets on groundwater radon concentration with those on simultaneously observed water temperature, and found that the temperature effects on the fluctuations in the observed radon concentration can be satisfactorily described by our procedure. Furthermore, we were able to estimate the original radon concentration in groundwater before it was introduced into the radon-detection chamber, which was not affected by water temperature changes. The obtained original radon concentrations are very stable during normal periods, and anomalous changes associated with earthquakes were easily detected. Our new method will be very useful to examine time-variation patterns of changes in groundwater radon and will provide important information about the mechanism of radon changes related to earthquakes.

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Section: Stochastic Differential Equationsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Time Series Analysis of Groundwater Radon Using Stochastic Differential Equations.

et al. 1995

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“…The most representative precursory radon change was that observed at SKE well in the Izu Peninsula for the M7.0 Izu-Oshima-kinkai earthquake on January 14, 1978 (Wakita et al, 1980). In addition, numerous radon anomalies associated with earthquakes have been observed at KSM well in Fukushima Prefecture (Wakita et al, 1989;Igarashi and Wakita, 1990;Igarashi et al, 1993). Kodai and Takahashi (1992) also discussed changes of the radon concentration observed in the Tokai district in connection with deep earthquakes.…”

Section: Introductionmentioning

confidence: 96%

Coseismic Radon Changes of the 1995 Hyogo-ken Nanbu Earthquake.

Ohno

Wakita

1996

J,Phys,Earth

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This article reports a preliminary result of seismic-related radon changes in groundwater observed at a continuous monitoring station in the Tokai district. Immediately after the M7.2 Hyogo-ken Nanbu earthquake which occurred on January 17, 1995, the radon concentration of a water well at a hypocentral distance of 260 km decreased by about 5%. It is meaningful that a drop in the radon concentration was observed, while the water level showed no significant change.

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“…Geochemical precursors are recognized as short-term precursor and are monitored in many countries both by discrete and continuous tools (Inan et al 2008;Kuo et al 2010), often preceded by area papers to install "sensitive stations" in sites recognized sound, during strong earthquakes in the past too, mostly if the role of fluids in triggering earthquakes is important (i.e., Italy, see Quattrocchi 1999). Radon is proved to be as one of the most reliable geochemical precursor (Wakita et al 1980;Fleischer 1981;Igarashi and Wakita 1990;Heinicke et al 1992;Igarashi et al 1995;Virk et al 2001;Steinitz et al 2003;Yang et al 2005;Zmazek et al 2005;Kumar et al 2009;Walia et al 2009a;Fu et al 2017a, b). Virk and Singh (1994) reported precursory radon anomalies simultaneously in both soil-gas and groundwater 5 days before the Uttarkashi Earthquake with a moment magnitude of 6.8 occurred on 20 October 1991, in Garhwal Himalayas, India.…”

Section: Introductionmentioning

confidence: 99%

Preseismic anomalies in soil-gas radon associated with 2016 M 6.6 Meinong earthquake, Southern Taiwan

Fu¹,

Walia²,

Yang³

et al. 2017

Terr. Atmos. Ocean. Sci.

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Taiwan is tectonically situated in a terrain resulting from the oblique collision between the Philippine Sea plate and the continental margin of the Asiatic plate, with a continuous stress causing the density of strong-moderate earthquakes and regional active faults. The continuous time series of soil radon for earthquake studies have been recorded and some significant variations associated with strong earthquakes have been observed. Earthquake prediction is not still operative but these correlations should be added to the literature about seismo-geochemical transients associated to strong earthquakes. Rain-pore pressure related variations, crustal weakness at the studied faults system is consistent with the simultaneous radon anomalies observed. During the observations, a significant increase of soil radon concentrations was observed at Chunglun-T1 (CL-T1), Hsinhua (HH), Pingtung (PT), and Chihshan (CS) stations approximately two weeks before the Meinong earthquake (M L = 6.6, 6 February 2016) in Southern Taiwan. The precursory changes in a multi-stations array may reflect the preparation stage of a large earthquake. Precursory signals are observed simultaneously and it can apply certain algorithms the approximate location and magnitude of the impending earthquake.

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Groundwater radon anomalies associated with earthquakes

Cited by 112 publications

References 16 publications

Time Series Analysis of Groundwater Radon Using Stochastic Differential Equations.

Time Series Analysis of Groundwater Radon Using Stochastic Differential Equations.

Coseismic Radon Changes of the 1995 Hyogo-ken Nanbu Earthquake.

Preseismic anomalies in soil-gas radon associated with 2016 M 6.6 Meinong earthquake, Southern Taiwan

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