Radon Anomaly: A Possible Precursor of the 1978 Izu-Oshima-kinkai Earthquake

Wakita, Hiroshi; Nakamura, Yuji; Notsu, Kenji; Noguchi, Michihiko; Asada, Toshi

doi:10.1126/science.207.4433.882

Cited by 193 publications

(98 citation statements)

References 2 publications

(1 reference statement)

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“…To study these in an effective way, instruments that monitor radon continuously at the wellhead will be needed. Such an instrument (as used by Wakita et al [1980]) was purchased from Japan and has been in operation at Fludir since August 1980. No earthquakes of magnitude greater than 2.0 occurred between August and December 1980 in the SISZ and the continuous data show that the radon content at Fludir has remained stable within a few percent.…”

Section: Discussionmentioning

confidence: 99%

“…First, the epicentral distance was plotted as a function of magnitude for radon anomalies that have been reported to be associated with the following earthquakes: Gasli (1976), USSR [Asimov et al, 1979];Szechwan Luhuo (1973), Szechwan Mapien (1973, China [Wakita, 1978]; Izu-Oshima (1978), Japan [Wakita et al, 1980]. The three anomalies observed at Fludir were also included in the plot.…”

Section: Local Seismicitymentioning

confidence: 99%

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Radon earthquake precursor studies in Iceland

Hauksson¹,

Goddard²

1981

J. Geophys. Res.

126

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Discrete samples of geothermal water have been collected from a network of nine stations for analysis of radon f22Rn) content. The sampling network consisted of wells that range in wellhead temperature from 48°C to l00°C, and the depths range from 38 m to 1338 m. The sampling frequency at most stations was about once per week and twice per week at the station Fludir. The wells are either artesian or pumped more or less continuously. The network covered two regions of transform faulting in Iceland with seven stations in the Southern Iceland Seismic Zone (SISZ) and two stations in northern Iceland in the Tjornes Fracture Zone (TFZ). During 1978 and 1979 several anomalous changes in radon content were observed to precede some of the local earthquakes. Criteria based on tectonic regimes, a magnitudedistance relationship and time clustering were applied to select a set of 23 earthquakes that could be expected to be preceded by a radon anomaly. The magnitude of these earthquakes ranged between 1.0 and 4.3. Each of the 23 earthquakes was within the distance range of one or more stations such that altogether 57 potential observations of possible anomalies were available. The method of analysis applied to the radon and earthquake data consisted ofidentifYing radon anomalies in retrospect, and resulted in nine precursory anomalies, 48 cases of failure to observe an anomaly, and seven false alarms. The probability of observing radon anomalies before earthquakes with magnitudes between 2.0 and 4.3 (the largest event observed) was found to be approximately 65% based on a weekly sampling rate. In the SISZ, five out of eight earthquakes (M > 2) were preceded by an anomaly. In two cases, anomalies were observed at two di1ferent stations prior to the same earthquake. The anomalies appeared to occur farther away for larger earthquake magnitude. An aquiclude that divides the SISZ did not seem to aJrect the occurrence of radon anomalies, but the amplitude of anomalies on the east side were larger than the ones on the west side. The duration times of the anomalies ranged from 17 to 37 days. The large number of failures to observe an anomaly indicated that the occurrence of an anomaly was more strongly dependent on local conditions and earthquake parameters than distance between epicenter and radon station. Some stations also appeared to be less sensitive than others and three stations never showed an anomaly. During periods of bursts in local seismicity, some stations reftected distinctively larger background ftuctuations, which hampered the correlation of the seismicity with the radon data. Most of the false alarms were related to disturbances caused by changes in well operation. In the SISZ the high rate of failure to observe an anomaly and the occurrence of false alarms was partly compensated for by operating a dense network of sampling stations. Wells that are utilized at moderate ftow rates are less likely to show false alarms than wells utilized at high ftow rates. Wells situated close to rock formations rich in radioactive mi...

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Section: Discussionmentioning

confidence: 99%

Section: Local Seismicitymentioning

confidence: 99%

Radon earthquake precursor studies in Iceland

Hauksson¹,

Goddard²

1981

J. Geophys. Res.

126

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“…Several other monitoring programs, although not reporting full data sets, have shown that coincident changes in chemical composition, temperature, and water level or flow rate often occur LI, 1981a, 1981b;WAKITA 1981WAKITA , 1982WAKITA , 1984MEI, 1984;ZHU eta/., 1984;BARSUKOV eta/., 1985;LI et al, 1985). The reported anomalies include examples of falling chloride and cation concentrations that are accompanied by decreasing temperatures and increasing flow rates or water levels (JIANG et al, 1981a;CAI et a/., 1984;LI et al, 1985), or declining radon concentrations that are accompanied by falling temperatures (WAKITA et al, 1980a;WAKITA, 1982WAKITA, , 1984. Hence, the chemical and hydrologic observations strongly suggest that mixing of chemically distinct groundwaters is the predominant effect responsible for many of the decreases in ion concentrations as well as the substantial increases in dissolved ion concentrations observed.…”

Section: Aquifer Breaching/fluid Mixing Modelmentioning

confidence: 99%

“…Recent monitoring programs have typically employed intermittent sampling from natural springs, shallow groundwater wells, or deep (2000m) monitoring wells, and have determined radon concentrations using gas-phase scintillation counting or liquid/liquid extraction of radon and liquid scintillation counting (FRIEDMANN and HERNEGGER, 1978;TALWANI et a/., 1980;TENG, 1980TENG, , 1984WAKITA et a/., 1980aWAKITA et a/., , 1985HAUKSSON, 1981a;HAUKSSON and GODDARD, 1981;ALLEGRI et a/., 1983;CHUNG, 1985;FRIEDMANN, 1985;KING, 1985aKING, , 1986LIV eta/., 1985;SHAPIRO eta/., 1985;SANTOYO et a/., 1987). Continuous monitoring of radon activities is now becoming a more accepted method, as the earlier results have shown that radon anomalies are frequently of short duration.…”

Section: Dissolved Gas Precursorsmentioning

confidence: 99%

Geochemical precursors to seismic activity

Thomas

1988

PAGEOPH

225

112

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Abstract-Studies of earthquake precursory phenomena during the last several decades have found that significant geophysical and geochemical changes can occur prior to intermediate and large earthquakes. Among the more intensely investigated geochemical phenomena have been: (1) changes in the concentrations of dissolved ions and gases in groundwaters and (2) variations in the concentrations of crustal and mantle volatiles in ground gases. The concentration changes have typically showed no consistent trend (either increasing or decreasing), and the spatial and temporal distribution of the observed anomalies have been highly variable. As a result, there is little agreement on the physical or chemical processes responsible for the observed anomalies. Mechanisms proposed to account for precursory groundwater anomalies include ultrasonic vibration, pressure sensitive solubility, pore volume collapse, fracture induced increases in reactive surfaces, and aquifer breaching/fluid mixing. Precursory changes in soil gas composition have been suggested to result from pore volume collapse, micro-fracture induced exposure of fresh reactive silicate surfaces, and breaching of buried gas-rich horizons. An analysis of the available field and laboratory data suggests that the aquifer breaching/fluid mixing (AB/FM) model can best account for many of the reported changes in temperature, dissolved ion and dissolved gas concentrations in groundwater. Ultrasonic vibration and pressure sensitive solubility models cannot reasonably account for the geochemical variations observed and, although the pore collapse model could explain some of the observed chemical changes in groundwater and ground gas, uncertainties remain regarding its ability to generate anomalies of the magnitude observed. Other geochemical anomalies, in particular those associated with hydrogen and radon, seem best accounted for by increases in reactive surface areas (IRSA model) that may accompany precursory deformation around the epicenter of an impending earthquake. Analysis of the probable response of these models to the earthquake preparation process, as well as to other environmental factors, suggests that geochemical monitoring programs can provide information that may be valuable in forecasting the probability of an earthquake; however, because of the complexity of the earthquake preparation process, the absolute prediction of seismic events using geochemical methods alone, does not presently appear to be feasible.

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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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Radon Anomaly: A Possible Precursor of the 1978 Izu-Oshima-kinkai Earthquake

Cited by 193 publications

References 2 publications

Radon earthquake precursor studies in Iceland

Radon earthquake precursor studies in Iceland

Geochemical precursors to seismic activity

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

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