Novel determination of radon‐222 velocity in deep subsurface rocks and the feasibility to using radon as an earthquake precursor

Zafrir, Hovav; Horin, Yochai Ben; Malik, U.; Chemo, Chaim; Zalevsky, Zeev

doi:10.1002/2016jb013033

Cited by 19 publications

(25 citation statements)

References 44 publications

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“…It is very important to collect the gas directly at the point where the fluids enter the borehole. Otherwise the measurements might be affected by external processes like "barometric pumping" inside the open well as described by Zafrir et al (2016).…”

Section: Discussion and Outlookmentioning

confidence: 99%

Multi-Level Gas Monitoring: A New Approach in Earthquake Research

et al. 2020

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Fluid anomalies were often considered as possible precursors before earthquakes. However, fluid properties at the surface can change for a variety of reasons, including environmental changes near the surface, the response of the superficial fluid system to loads associated with the mechanical nucleation of earthquake fractures, or as a result of transients in fluid flow from the depths. A key problem is to understand the origin of the anomaly and to distinguish between different causes. We present a new approach to monitor geochemical and geophysical fluid properties along a vertical profile in a set of drillings from a depth of a few hundred meters to the surface. This setup can provide hints on the origin of temporal variations, as the migration direction and speed of properties can be measured. In addition, potential admixtures of fluids from a deep crustal or mantle origin with meteoric fluids can be better quantified. A prototype of a multi-level gas monitoring system comprising flow and pressure probes, as well as monitoring of fluid-geochemical properties and stable isotopes is being implemented in a mofette field with massive CO 2 (up to 97 tons per day) degassing. The mofette is believed a gas emission site where CO 2 ascends through crustal-scale conduits from as deep as the upper mantle, and may therefore provide a natural window to ongoing magmatic processes at mantle depth. Fluids from three adjacent boreholes-30, 70, and 230 m deep-will be continuously monitored at high sampling rates.

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Section: Discussion and Outlookmentioning

confidence: 99%

Multi-Level Gas Monitoring: A New Approach in Earthquake Research

et al. 2020

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“…Intuitively radon sensor deployed in shelter and specially in boreholes should be less sensitive to climatic effects, but such rule is not unequivocal in the analysed time series (Figure S5). In the literature also the semi-diurnal cycle is encountered in most of the radon series 8,11,14,30,33,34 and mainly correlated to the semi-diurnal atmospheric pressure effects, often referred as barometric tide 35 . The occurrence of a significant effect due to pressure is not surprising.…”

Section: Discussionmentioning

confidence: 99%

“…The relatioships between radon and the environmental processes concern the volcanic activity, tracing in atmospheric, marine and hydro-geological issues, it is studied as a tracer of tectonic activity and earthquake precursor 1–3 . Indeed, the latter topic encounters a great interest worldwide since clues of tectonic-induced anomalies in radon signals have been suggested in several cases 2,4–8 . Such anomalies likely arise from the preparatory crust fracturing processes leading to an earthquake: the release of stress within the crust eases the migration of radon from deeper sources.…”

Section: Introductionmentioning

confidence: 99%

Multiple seasonality in soil radon time series

Siino

Scudero

Cannelli

et al. 2019

Sci Rep

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The dynamics governing the movement of the radon are complex and dependent on many factors. In the present study, we characterise the nature of temporal variations of 2-hourly and daily radon measurements in several monitoring sites of the Italian Radon mOnitoring Network (IRON) in Italy. By means of continuous wavelet transformation, a spectral analysis in time-frequency domain is performed. The results reveal that there are sub-daily, daily and yearly persistent periodicities that are common for all the stations. We observe structural seasonal breaks, that occur at the same frequency but at distinct time. Variations in radon concentration and local temperature are studied in terms of frequency contents and synchronicity. When analysing several long time series together, it is evident that the phase difference at low frequency movements (365-day period) between the radon and local temperature time series is depending on the sites’ location and therefore strongly controlled by local factors. This could at least partially explain the apparently contrasting results available in the literature obtained investigating smaller dataset about the relationships between temperature and radon variations. On the other hand, results show that all radon time series are characterised by marked cycles at 1 and 365-days and less evident cycles at 0.5-day and 180-days. They would be all ascribable to environmental-climatic factors: the short-period cycles to temperature and pressure variations, the long-period cycles also to seasonal rainfall variations.

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“…Among them, the hydrogeochemical response of earthquake activity has been extensively studied for the last few decades [24]. The hydrogeochemical studies mainly include the monitoring in water level changes, Rn variability in either air, soil, or groundwater, an emanation of soil gases (CO 2 , CH 4 , and He), and other constituents such as Cl − , SO 2− 4 , and HCO − 3 are also used as a forerunner to access the earthquake-induced changes [7,10,11,[24][25][26][27]. However, the use of Rn is globally preferred in comparison with other precursors due to its relatively long half-life and ease of predictability [14].…”

Section: Introductionmentioning

confidence: 99%

Implication of Radon Monitoring for Earthquake Surveillance Using Statistical Techniques: A Case Study of Wenchuan Earthquake

et al. 2020

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The seismotectonically induced changes in groundwater radon (Rn) are considered to be strong imputes for the surveillance of imminent major earthquakes. Groundwater facilitates the migration of soil gases as a result of tectonic stresses. In this regard, a radon time series is statistically analysed to identify the radon anomalies possibly induced by Wenchuan earthquake. The statistical analysis mainly involves the deterministic analysis of the Rn data and residual Rn analysis using a criterion x¯±2σ of anomaly selection having a confidence interval of 95%. The deterministic analysis reveals that the Rn time series follows a persistent trend 0.5≤H≤1 which confirms the absence of a chaotic regime. On the other hand, the residual Rn shows a notable upsurge straddling the time of the Wenchuan earthquake in the form of pre- and post earthquake changes at monitoring stations having RE/RD≤0.3. The residual Rn level passes the anomaly selection criterion x¯±2σ and is declared as a tectonically induced Rn anomaly. Contrary to this, the response of distant monitoring stations (RE/RD>0.3) to this particular earthquake further validates the link between Rn and earthquake activity. In a nutshell, the present study highlights the potential implications of earthquake-induced radon anomalies for earthquake prediction research.

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Novel determination of radon‐222 velocity in deep subsurface rocks and the feasibility to using radon as an earthquake precursor

Cited by 19 publications

References 44 publications

Multi-Level Gas Monitoring: A New Approach in Earthquake Research

Multi-Level Gas Monitoring: A New Approach in Earthquake Research

Multiple seasonality in soil radon time series

Implication of Radon Monitoring for Earthquake Surveillance Using Statistical Techniques: A Case Study of Wenchuan Earthquake

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