Using 222Rn as a tracer of geodynamical processes in underground environments

Valladares, D.L.; Silva, A.A.R. da; Lacerda, T.; Anjos, R. M.; Velasco, H.; Rosas, Juan Pablo de; Tognelli, G.; Yoshimura, Elisabeth Mateus; Ayub, J. Juri

doi:10.1016/j.scitotenv.2013.08.003

Cited by 6 publications

(2 citation statements)

References 31 publications

(44 reference statements)

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“…The process is also confirmed by the 222 Rn concentration, a good indicator of the connexion between the subterranean environment and the atmosphere (Valladares et al, 2014), which, simultaneously to the CO2, suffers a sharp decrease as consequence of the ventilation.…”

mentioning

confidence: 75%

Changes in the CO2 dynamics in near-surface cavities under a future warming scenario: Factors and evidence from the field and experimental findings

Pla

Cuezva

Garcia-Anton

et al. 2016

Science of The Total Environment

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This study is based in a field monitoring of a cave-soil-atmosphere system validated with laboratory experimentation. CO2 and 222 Rn dynamics in the cavity demonstrate the dependence on the climatic parameters, mainly on the differences between outdoor and indoor temperatures. Within the cave, the annual cycles are characterized by two outstanding moments: cave gaseous recharge and ventilation when cave acts as gaseous sink or source respectively. Relationship with soil above the cave exists permanently. Soil temperature and moisture are responsible for CO2 production at different time scales.Soil CO2 in Rull site reaches values higher than 3000 ppm in April-May, which falls to nearly 1000 ppm during the summer time. Due to CO 2 diffusion, maximum values in the cave are reached in the warmest months and are in accordance to soil CO2 values. Within the cave, maximum CO2 concentration is, in average, 3470 ppm while minimum is 623 ppm. Cave temperature and relative humidity remain quite stable with mean values of 16.1 ºC and 97.9% respectively. To describe field findings, CO2 production and diffusion experiments are developed related to soil behaviour. Results show that soil CO2 production increases as soil temperature and moisture increase according to a calculated logarithmic equation until water content in soil exceeds the saturation values. In addition, CO2 diffusion in Rull soil is reduced around 60% when water content in soil increases from 0 to 30%. Soil-produced CO2 reaches Rull cave, by diffusion. We estimate 57 kg of emitted CO2 from the cave to the atmosphere in an annual cycle, considering a volume of 9915 m 3 . Finally, projections of future climate in the study site confirm a general tendency for annual-mean conditions to be warmer and drier, which will directly affect soil CO2 production. Under this situation, Rull cave will experience changes in the stored and then exchanged annual amount of CO2.

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mentioning

confidence: 75%

Changes in the CO2 dynamics in near-surface cavities under a future warming scenario: Factors and evidence from the field and experimental findings

Pla

Cuezva

Garcia-Anton

et al. 2016

Science of The Total Environment

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“…In a recent study, it was possible to verify that the La Carolina mine main tunnel works as a blind end system communicating with the external air only through one entrance. This occurs in summer (period when the measurements presented here were done) mainly because the temperature difference between the inside and outside temperatures is small (DT = 1 °C) [18]. These conditions are rarely fulfilled in human living environments, where there is more ventilation, and the dynamics of change of radon concentration is more challenging.…”

Section: Correlation Rn-dose Ratementioning

confidence: 99%

Radon concentration in air and external gamma dose rate: is there a correlation?

Yoshimura

Anjos

Umisedo

et al. 2015

J Radioanal Nucl Chem

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We checked the existence of correlations between experimentally determined radon concentration in indoor air and gamma dose rate, in different environments: residences, workplaces in subway stations and radiotherapies, and a gold mine. Except for the mine environment, where a linear correlation (r 2 = 0.86) was obtained with statistical significance, we found no correlations between those quantities. Both radiation sources are originated from natural radionuclides, nonetheless the observation of correlations depends on various conditions, as we discuss here.

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Assessment of CO2 dynamics in subsurface atmospheres using the wavelet approach: from cavity–atmosphere exchange to anthropogenic impacts in Rull cave (Vall d′Ebo, Spain)

et al. 2016

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Using 222Rn as a tracer of geodynamical processes in underground environments

Cited by 6 publications

References 31 publications

Changes in the CO2 dynamics in near-surface cavities under a future warming scenario: Factors and evidence from the field and experimental findings

Changes in the CO2 dynamics in near-surface cavities under a future warming scenario: Factors and evidence from the field and experimental findings

Radon concentration in air and external gamma dose rate: is there a correlation?

Assessment of CO2 dynamics in subsurface atmospheres using the wavelet approach: from cavity–atmosphere exchange to anthropogenic impacts in Rull cave (Vall d′Ebo, Spain)

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