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Radium isotopes have been used to trace nutrient, carbon, and trace metal fluxes inputs from ocean margins. However, these approaches require a full accounting of radium sources to the coastal ocean including rivers. Here, we aim to quantify river radium inputs into the Arctic Ocean for the first time for 226Ra and to refine the estimates for 228Ra. Using new and existing data, we find that the estimated combined (dissolved plus desorbed) annual 226Ra and 228Ra fluxes to the Arctic Ocean are [7.0–9.4] × 1014 dpm y−1 and [15–18] × 1014 dpm y−1, respectively. Of these totals, 44% and 60% of the river 226Ra and 228Ra, respectively are from suspended sediment desorption, which were estimated from laboratory incubation experiments. Using Ra isotope data from 20 major rivers around the world, we derived global annual 226Ra and 228Ra fluxes of [7.4–17] × 1015 and [15–27] × 1015 dpm y−1, respectively. As climate change spurs rapid Arctic warming, hydrological cycles are intensifying and coastal ice cover and permafrost are diminishing. These river radium inputs to the Arctic Ocean will serve as a valuable baseline as we attempt to understand the changes that warming temperatures are having on fluxes of biogeochemically important elements to the Arctic coastal zone.

The interaction of surface water and groundwater is important in the ecology of coastal basins, affecting hydrological conditions, oxygen regime, carbon, and nutrient exchange. This study demonstrates a dynamic connection between the salt-wedge region and its underlying aquifer in the eutrophic estuary. In winter, this estuary is covered with ice, and the river flow is at its lowest; that is why the specific response to groundwater discharge is best marked in this season. Groundwater admixture was detected in the salt-wedge region by highly active radium isotopes: 223Ra—4.80 ± 0.42 dpm 100 L−1, 224Ra—55.37 ± 1.1 dpm 100 L−1, and 228Ra—189.71 ± 4.66 dpm 100 L−1. The temperature of groundwater and river water was about +4 °C and 0 °C, respectively; that of seawater was −1.6 °C, and temperature increased up to +2.3 °C in the surface water–groundwater interaction region. Groundwater admixture is accompanied by a lower level of oxygen concentration of 52 μmol/kg; at that time, the maximum oxygen concentration in the salt-wedge region was 567 μmol/kg. In waters with a high activity of radium isotopes, there was a maximum partial pressure of CO2—4454 μatm at the range 100–150 μatm in the salt-wedge region and also observed extremum of NH4+, NO2−, and dissolved phosphorus. The surface water–groundwater interaction through anoxic sediment can form localized anaerobic areas despite the general oxygen supersaturation of eutrophic estuary waters and also cause local recycling of nutrients from bottom sediments.

Riverine carbon flux to the ocean has been considered in estimating coastal carbon budgets, but submarine groundwater discharge (SGD) has long been ignored. In this paper, the effects of both SGD and river discharges on the carbon cycle were investigated in the Guangdong-HongKong-Macao Greater Bay Area (GBA), a highly urbanized and river-dominated coastal area in China. SGD-derived nitrate (NO3–), dissolved organic carbon (DOC), and dissolved inorganic carbon (DIC) fluxes were estimated using a radium model to be (0.73–16.4) × 108 g/d, (0.60–9.94) × 109 g/d, and (0.77–3.29) × 1010 g/d, respectively. SGD-derived DOC and DIC fluxes are ∼2 times as great as riverine inputs, but SGD-derived NO3– flux is one-fourth of the riverine input. The additional nitrate and carbon inputs can stimulate new primary production, enhance biological pump efficiency, and affect the balance of the carbonate system in marine water. We found that SGD in the studied system is a potential net source of atmospheric CO2 with a flux of 1.46 × 109 g C/d, and river, however, is a potential net sink of atmospheric CO2 with a flux of 3.75 × 109 g C/d during the dry winter season. Two conceptual models were proposed illustrating the major potential processes of the carbon cycle induced by SGD and river discharges. These findings from this study suggested that SGD, as important as rivers, plays a significant role in the carbon cycle and should be considered in carbon budget estimations at regional and global scales future.

The residence time of fluids circulating through deep-sea hydrothermal systems influences the extent of water-rock reactions and the flux of major and minor elements to the ocean. While the fluid residence times in numerous basaltic and gabbroic systems have been determined, those of the less studied ultramafic systems are currently unknown. Fluids that interact with mantle rocks have fundamentally different chemistries and therefore have unique influences on seawater chemistry. In this first investigation of radium isotopes in a serpentinite-hosted system, vent fluids were discovered to contain 10–100 times greater activities of 223Ra (half-life = 11.4 days) than observed in high-temperature basalt-hosted systems. The 223Ra activities of 10–109 dpm L−1 produce 223Ra/226Ra activity ratios ranging from 9 to 109. These extremely high 223Ra activities, which are accompanied by low activities of 226Ra, place significant constraints on fluid residence times and the adsorption coefficient of radium between fluid and rock. Our data constrain the nondimensional retardation factor (R) to very low values between 1 and 4, reflecting the extent to which Ra is transported more slowly than fluids due to adsorption and other processes. These results suggest that the residence time of fluids in contact with serpentinite is less than 2 y and perhaps as low as 0.5 y. They are surprisingly similar to those of basalt-hosted systems. Thus, fluids in hydrothermal systems share similar hydrogeological characteristics despite differences in rock types, underlying porosity, and heat sources, enabling larger-scale models of hydrothermal biogeochemistry to be developed across systems., Journal of Geophysical Research: Oceans, 126 (12), ISSN:0148-0227, ISSN:2169-9275

2-s2.0-85074780852, Elevated concentrations of the radium isotopes 224,226,228Ra exist in the scale and produced water in oil exploration. The activity concentration of 226Ra was calculated from 186.2 keV peak with no usual spectral interference of 185.7 from 235U. The activity concentration of 228Ra was calculated from its first daughter product 228Ac using the 911.2 keV gamma rays since it is a pure beta emitter. The activity concentration of 224Ra was calculated from 212Pb using the 238.6 keV gamma-ray and the secular equilibrium equation with 228Ra. The IAEA 448 (oil contaminated field soil) reference material was used as a quality control for 226,228Ra and but was unreliable for 224Ra using 212Pb. © 2019, Akadémiai Kiadó, Budapest, Hungary.

Submarine groundwater discharge (SGD) is a significant source of biogenic elements in estuaries, and relevant studies in karstic estuaries are scarce. Krka River Estuary (KRE), located on the eastern Adriatic Sea (Croatia), is a typical oligotrophic stratified karstic estuary. In this study, based on 226Ra and 228Ra, the total SGD flux into the KRE surface layer was estimated to be (12.8‐16.2) × 105 m3 d‐1. A conservative estimation of the fresh groundwater flux was (5.0‐8.3) × 105 m3 d‐1, which accounts for 10‐17 % of the Krka River discharge into the estuary. By establishing water and nutrient budgets in the KRE surface layer, we found that SGD dominated the nutrient sources, although it accounted for a small portion of the total inflow water. Specifically, net SGD‐derived dissolved inorganic nitrogen (DIN) and silicates contributed 58‐90 % and 24‐64 %, respectively, to the total input fluxes. These results indicate that SGD was a major external nutrient source, in which net SGD‐derived high DIN flux and high DIN to dissolved inorganic phosphorus ratio may affect productivity in the KRE ecosystem and nearby Adriatic Sea. Additionally, net SGD‐derived dissolved inorganic carbon (DIC) flux in the KRE (1.53 mol m‐2 d‐1) was much higher than those in most estuaries worldwide, suggesting that the DIC‐ enriched karst aquifers are important sources for global carbon cycle. Therefore, the impact of net SGD‐derived DIC from karst aquifers on coastal seas will likely become more evident and substantial with further development of global climate change, such as sea level rise.

Made available in DSpace on 2021-06-25T10:19:20Z (GMT). No. of bitstreams: 0 Previous issue date: 2021-01-01 Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) This paper describes a methodology developed to measure the activity concentration of the four natural radium isotopes 226Ra, 228Ra, 224Ra and 223Ra in water samples, using γ-ray analysis performed with a hyperpure germanium detector (HPGe). The detector efficiency was properly determined using a set of thorium standards exhibiting concentrations between 10 and 10,000 μg/g. The developed analytical protocol was applied for evaluating the radium activity concentration in groundwater samples providing from different aquifer systems in three Brazilian states. The results were compared with the guideline reference values for 226Ra and 228Ra as proposed by the Brazilian and WHO legislations. Departamento de Geologia Universidade Estadual Paulista (UNESP), Câmpus de Rio Claro, Av. 24-A No.1515, C.P. 178, CEP Departamento de Geologia Universidade Estadual Paulista (UNESP), Câmpus de Rio Claro, Av. 24-A No.1515, C.P. 178, CEP

Estimation of submarine groundwater discharge (SGD) to semi-enclosed basins by Ra isotope mass balance is herein assessed. We evaluate 224Ra, 226Ra, and 228Ra distributions in surface and bottom waters of Long Island Sound (CT-NY, United States) collected during spring 2009 and summer 2010. Surface water and bottom water Ra activities display an apparent seasonality, with greater activities during the summer. Long-lived Ra isotope mass balances are highly sensitive to boundary fluxes (water flux and Ra activity). Variation (50%) in the 224Ra, 226Ra, and 228Ra offshore seawater activity results in a 63–74% change in the basin-wide 226Ra SGD flux and a 58–60% change in the 228Ra SGD flux, but only a 4–9% change in the 224Ra SGD flux. This highlights the need to accurately constrain long-lived Ra activities in the inflowing and outflowing water, as well as water fluxes across boundaries. Short-lived Ra isotope mass balances are sensitive to internal Ra fluxes, including desorption from resuspended particles and inputs from sediment diffusion and bioturbation. A 50% increase in the sediment diffusive flux of 224Ra, 226Ra, and 228Ra results in a ∼30% decrease in the 224Ra SGD flux, but only a ∼6–10% decrease in the 226Ra and 228Ra SGD flux. When boundary mixing is uncertain, 224Ra is the preferred tracer of SGD if sediment contributions are adequately constrained. When boundary mixing is well-constrained, 226Ra and 228Ra are the preferred tracers of SGD, as sediment contributions become less important. A three-dimensional numerical model is used to constrain boundary mixing in Long Island Sound (LIS), with mean SGD fluxes of 1.2 ± 0.9 × 1013 L y–1 during spring 2009 and 3.3 ± 0.7 × 1013 L y–1 during summer 2010. The SGD flux to LIS during summer 2010 was one order of magnitude greater than the freshwater inflow from the Connecticut River. The maximum marine SGD-driven N flux is 14 ± 11 × 108 mol N y–1 and rivals the N load of the Connecticut River.

Determination of submarine groundwater discharge (SGD) from karstic coastal aquifers is important to constrain hydrological and biogeochemical cycles. However, SGD quantification using commonly employed geochemical methods can be difficult to constrain under the presence of large riverine inputs, and is further complicated by the determination of the karstic groundwater endmember. Here, we investigated a coastal region where groundwater discharges from a karstic aquifer system using airborne thermal infrared mapping and geochemical sampling conducted along offshore transects. We report radium data (223Ra, 224Ra, 228Ra) that we used to derive fluxes (water, nutrients) associated with terrestrial groundwater discharge and/or seawater circulation through the nearshore permeable sediments and coastal aquifer. Field work was conducted at different periods of the year to study the temporal variability of the chemical fluxes. Offshore transects of 223Ra and 224Ra were used to derive horizontal eddy diffusivity coefficients that were subsequently combined with surface water nutrient gradients (NO2− + NO3−, DSi) to determine the net nutrient fluxes from SGD. The estimated DSi and (NO2− + NO3−) fluxes are 6.2 ± 5.0 *103 and 4.0 ± 2.0 *103 mol d−1 per km of coastline, respectively. We attempted to further constrain these SGD fluxes by combining horizontal eddy diffusivity and 228Ra gradients. However, SGD endmember selection in this area (terrestrial groundwater discharge vs. porewater) adds further uncertainty to the flux calculation and thus prevented us from calculating a reliable flux using this latter method. Additionally, the relatively long half-life of 228Ra (5.75 y) makes it sensitive to specific circulation patterns in this coastal region, including sporadic intrusions of Rhône river waters that impact both the 228Ra and nutrient surface water distributions. We show that SGD nutrient fluxes locally reach up to 20 times the nutrient fluxes from a small river (Huveaune River). On a regional scale, DSi fluxes driven by SGD vary between 0.1 and 1.4% of the DSi inputs of the Rhône River, while the (NO2− + NO3−) fluxes driven by SGD on this 22 km long coastline are between 0.1 and 0.3% of the Rhône River inputs, the largest river that discharges into the Mediterranean Sea. Interestingly, the nutrient fluxes reported here are similar in magnitude compared with the fluxes quantified along the sandy beach of La Franqui, in the western Gulf of Lions (Tamborski et al., 2018), despite the different lithology of the two areas (karst systems vs. unconsolidated sediment).

International audience; Groundwater springs in karstified carbonate aquifers are known to transport carbon, nutrients and trace elements to the coastal ocean. The biogeochemical significance of submarine karstic springs and their impact on coastal primary production are often difficult to quantify. We investigated several karstic springs, including the first-order Port-Miou spring, in an urbanized watershed that is also severely impacted by sewage effluent (Calanques of Marseille-Cassis, France). Karstic springs were elevated in major nutrients and bioactive trace metals over Mediterranean seawater, with relatively low concentration ranges. Groundwater NO3- was likely derived from atmosphere-aquifer interactions, while DOC:DON ratios reveal that NO2- and NH4+ was autochthonously produced during mixing between karst groundwater and seawater. Submarine groundwater discharge (SGD) during March 2018 (wet season, baseflow conditions) was 6.7 ± 2.0 m3 s-1 for the entire investigated coastline, determined from simultaneous 224Ra and 226Ra mass balances. The contribution of groundwater PO43-, the major limiting nutrient of the Mediterranean Sea, sustained only 1% of primary production adjacent to sewage outfall, but between 7 and 100% of the local primary production in areas that were not impacted by sewage. Groundwater and seawater Fe:DIN and Fe:DIP ratios suggest that Fe was not a limiting micro-nutrient during the period of study, where bioactive trace metal fluxes were dominated by sewage and atmospheric deposition, although excess Fe from groundwater may locally enhance N fixation. Groundwater solute fluxes may easily vary by a factor of two or more over time because karst aquifers are sensitive to precipitation, as is the case of the regional carbonate karstified aquifer of Port-Miou, highlighting the critical importance of properly characterizing nutrient and trace metal inputs in these coastal environments.

International audience; Submarine Groundwater Discharge (SGD) has received increased attention in recent years since it was recognized that it may be both volumetrically and chemically important. Around the Mediterranean Sea, 60% of the coastline is composed of karstic aquifers, and to properly estimate the hydrological budget of the Mediterranean Sea it is therefore necessary to better assess the karstic submarine groundwater discharges (KSGD). However, quantifying KSGD is still challenging. Among the methods recently developed to detect and quantify SGD, the mass balance method of the radium quartet 223 Ra, 224 Ra, 226 Ra and 228 Ra has proved to be a powerful technique. This approach requires characterizing all the contributing terms and sinks in the coastal water volume affected by SGD, the residence time of coastal waters, as well as a representative concentration of the tracers for both surface water and discharging groundwater. In this study we combine several approaches (223 Ra, 224 Ra, salinity profiles and Acoustic Doppler Current Profiler (ADCP) measurements) to examine both the accuracy and sensitivity of the radium mass balance method in the case of the cove of Port-Miou (Mediterranean Sea, France) where the main karstic spring discharges locally at 10 m depth. This study benefits from the inland in-situ access to the main karst conduit discharging to the sea which provides a long time series to characterize 2 the brackish submarine groundwater end-member. We show that the composition of the cove water is stratified, with two water bodies: a surface brackish layer and a deeper layer. The mean KSGD value obtained with 223 Ra and 224 Ra mass balances in the surface water body is precise but significantly lower (0.6 ± 0.1 m 3 /s) than the karstic spring discharge (4 ± 1 m 3 /s) estimated within the karst conduit with pressure sensors. The residence time of the cove water estimated using both 224 Ra and 223 Ra isotopes is very low (1 ± 1 day). Our study shows that the water residence time that we calculated using the Ra mass balance is the key parameter that may impact KSGD. In addition, based on ADCP transects, we suggest that the shape and geometry of the cove, as well as the location of the discharge point of the spring play a key role in explaining these discrepant results. We therefore recommend that in such stratified coves, estimations of KSGD based on short-lived radium isotopes require accurate and independent estimates of the water residence time as well as a good knowledge of the shallow and deep circulation patterns of the cove water.

The estuary-bay system is a common and complex coastal environment. However, quantifying submarine groundwater discharge (SGD) and associated nutrient fluxes in the complex coastal environment is challenging due to more dynamic and complicated riverine discharge, ocean processes and human activities. In this study, SGD and SFGD (submarine fresh groundwater discharge) fluxes were evaluated by combining stable and radium isotopes in the Guangdong-Hong Kong-Macau Greater Bay Area (GBA), a typical estuary-bay system. We first built a spatially distributed radium mass balance model to quantify SGD fluxes in coastal areas of GBA integrating the Pearl River Estuary (PRE), bays and shelf. We then used the stable water isotope (δ2H and δ18O) end-member mixing model to distinguish submarine fresh groundwater discharge (SFGD) from SGD. Based on the 228Ra mass balance, the estimated SGD fluxes in the PRE, adjacent bay, and shelf areas were (6.14 ± 2.74) × 108 m3 d-1, (3.00 ± 1.11) × 107 m3 d-1, and (5.00 ± 5.64) × 108 m3 d-1, respectively. Results showed that the largest area-averaged SGD was in the PRE, followed by that in the adjacent shelf and the bay. These differences may be mainly influenced by ocean forces, urbanization and benthic topographies controlling the variability of groundwater pathways. Further, the three end-member mixing model of 228Ra and salinity was developed to confirm the validity of the estimated SGD using the Ra mass balance model. In the two models, groundwater end-member and water apparent age estimation were the main sources of uncertainty in SGD. The estimated SFGD flux was (1.39 ± 0.76) × 108 m3 d-1, which accounted for approximately 12% of the total SGD. Combining stable and radium isotopes was a useful method to estimate groundwater discharge. Moreover, the estimated SGD associated dissolved inorganic nitrogen (DIN) flux was one order of magnitude higher than other DIN sources. SGD was considered to be a significant contributor to the DIN loading to the GBA. The findings of this study are expected to provide valuable information on coastal groundwater management and environmental protection of the GBA and similar coastal areas elsewhere.

International audience; The number of studies concerning Submarine Groundwater Discharge (SGD) grew quickly as we entered the twenty-first century. Many hydrological and oceanographic processes that drive and influence SGD were identified and characterized during this period. These processes included tidal effects on SGD, water and solute fluxes, biogeochemical transformations through the subterranean estuary, and material transport via SGD from land to sea. Here we compile and summarize the significant progress in SGD assessment methodologies, considering both the terrestrial and marine driving forces, and local as well as global evaluations of groundwater discharge with an emphasis on investigations published over the past decade. Our treatment presents the state-of-the-art progress of SGD studies from geophysical, geochemical, bio-ecological, economic, and cultural perspectives. We identify and summarize remaining research questions, make recommendations for future research directions, and discuss potential future challenges, including impacts of climate change on SGD and improved estimates of the global magnitude of SGD.

WOS: 000494414100001, Elevated concentrations of the radium isotopes Ra-224,Ra-226,Ra-228 exist in the scale and produced water in oil exploration. the activity concentration of Ra-226 was calculated from 186.2 keV peak with no usual spectral interference of 185.7 from U-235. the activity concentration of Ra-228 was calculated from its first daughter product Ac-228 using the 911.2 keV gamma rays since it is a pure beta emitter. the activity concentration of Ra-224 was calculated from Pb-212 using the 238.6 keV gamma-ray and the secular equilibrium equation with Ra-228. the IAEA 448 (oil contaminated field soil) reference material was used as a quality control for Ra-226,Ra-228 and but was unreliable for Ra-224 using Pb-212.

Trace elements (TEs) play crucial roles in regulating ocean processes including marine biogeochemical cycles, and are therefore vital to support marine life. Understanding the biogeochemical cycling of TEs requires knowledge of their sources/ sinks and transport in the oceans. Radium isotopes are suitable tools to study inputs of elements from the continental margins, as they are produced by the decay of thorium isotopes in sediments, and are soluble in seawater. Therefore, in this Ph.D. thesis, I used Ra isotopes to determine boundary TE fluxes from two diverse environments that constrain the major TE sources, including shelf sediments in an Arctic shelf region and in an eastern boundary system off the western African coast, as well as rivers such as the River Congo. First, the distributions of the dissolved and total dissolvable TEs (Cd, Fe, Ni, Cu, Zn, Pb, Mn, and Co) were investigated in the Chukchi Sea and 228Ra isotope was applied as tracer of benthic TE inputs. The results show that elevated benthic TE inputs on the Chukchi shelf provided suitable conditions for phytoplankton blooms. The 228Ra activities in spring appear to be 2-fold higher than in summer, which was a surprising observation and requires further investigation. Next, 228Ra was used to investigate the influence of the Congo River on surface ocean TE concentrations in the South Atlantic Ocean. The results show that the Congo River plume constitutes a large and unexpected input of TEs (Fe, Mn, and Co) into the South Atlantic. Finally, Ra isotopes were used to investigate a number of key ocean boundary processes in the Southeast Atlantic Ocean. Upwelling in the Benguela region is visible in the Ra distributions, and elevated Ra isotopes, Fe (II) and Si concentrations were observed in the Benguela oxygen minimum zone, possibly due to inputs from the reducing shelf sediments, or submarine groundwater discharge along the Namibian shelf. Spurenelemente spielen eine zentrale Rolle in der Regulation ozeanischer Prozesse einschließlich des marinen biogeochemischen Kreislaufs und sind dadurch eine zentrale Voraussetzung für das Leben im Meer. Das Verständnis der biogeochemischen Kreisläufe der Spurenelemente basiert auf dem Wissen um deren Quellen, Senken und Transportwege innerhalb des Ozeans. Die Radiumisotope, welche als Zerfallsprodukt von Thorium in Sedimenten entstehen, sind wasserlöslich und haben sich als nützliche Werkzeuge herausgestellt, die den Input von solchen Elementen aus den kontinentalen Hängen nachvollziehen lassen. Diese verwende ich in der vorliegenden Dissertation, um die bedeutendsten Spurenelementquellen zu beleuchten, die den Austausch zwischen Schelfsedimenten und dem angrenzenden Ozean vornehmen. Dies geschieht anhand zweier kontrastierender Umgebungen, dem arktischen Schelf und des östlichen „Grenzsystems“ vor der Küste Westafrikas, das auch Flusseinträge wie zum Beispiel aus dem Kongo beinhaltet. Zunächst wurde die Verteilung der gelösten und säurelöslichen Spurenelemente (Cd, Fe, Ni, Cu, Zn, Pb, Mn und Co) in der Tschuktschensee untersucht. Als Tracer zur Bestimmung benthischen Eintrags wurde dort 228Ra verwendet. Des Weiteren wurde 228Ra verwendet, um den Einfluss des Kongo, auf die im oberen Ozean befindlichen Spurenelemente im Südatlantik zu untersuchen. Die Ergebnisse zeigen, dass die Flusswasserfahne des Kongo einen unerwartet großen Eintrag bioessentieller Spurenelemente in den Südatlantik ausmacht. Mit Hilfe der Radiumisotope wurden abschließend eine Reihe von Schlüsselprozessen im Grenzflächenaustausch des Südost-Atlantiks untersucht. Der Auftrieb der Benguela-Region ist ebenfalls in der Radiumverteilung ersichtlich. Gleichzeitig weisen erhöhte Konzentrationen der Radiumisotope, Fe (II) und Si in der Benguela-Sauerstoffminimumzone auf Zufuhr aus reduzierenden Schelfsedimenten oder aus unterseeischem Grundwasseraustritt entlang des Namibianischen Schelfs hin.

Radon isotopes (222Rn, 220Rn) are noble, naturally occurring radioactive gases. They originate from the alpha decay of radium isotopes (226Ra, 224Ra), which occur in most materials in the environment, i.e. soil, rocks, raw and building materials. Radon is also found in ground and tap water. The two radon isotopes are chemically identical, but they have very different halflives: 3.82 days for radon (222Rn) and 56 seconds for thoron (220Rn). Thus, they behave very differently in the environment. Both isotopes are alpha-emitters; their decay products are polonium, bismuth and lead isotopes. Peer Reviewed Objectius de Desenvolupament Sostenible::13 - Acció per al Clima

The Viimsi peninsula is located north-east of Tallinn, capital of Estonia. The Cambrian-Vendian (Cm-V) aquifer system is a sole source of drinking water in the area. Historically, the groundwater exploitation has led to freshening of groundwater in the peninsula, but in recent years an increase in chloride concentrations and enrichment in &delta, 18O values has been detected, but in recent years hydrochemical parameters indicate an increasing influence of a saline water source. The exact origin of this saline water has remained unclear. The aim of the current study is to elucidate whether the increase in Cl&minus, concentrations is related to seawater intrusion or to the infiltration of saline water from the underlying crystalline basement. To identify the source of salinity, chemical composition of the groundwater and the isotope tracers (e.g., &delta, 18O and radium isotopes) were studied in the Viimsi peninsula in the period from 1987 to 2018. Our results show that chemical composition of Cm-V groundwater in the peninsula is clearly controlled by three-component mixing between glacial palaeogroundwater, saline water from the underling crystalline basement and modern meteoric water. The concentrations of Ra are also significantly affected by the mixing, but the spatial variation of radium isotopes (226Ra and 228Ra) suggests the widespread occurrence of the U in the surrounding sedimentary sequence. Our hypothesis is that, in addition to U originating from the crystalline basement, some U could be associated with secondary U deposits in sedimentary rocks. The formation of these secondary U deposits could be related to glacial meltwater intrusion in the Pleistocene. Although the results suggest that the infiltration of saline groundwater from the underlying crystalline basement as the main source of salinity in the study area, the risk of seawater intrusion in the future cannot be ruled out. It needs to be highlighted that the present groundwater monitoring networks may not be precise enough to detect the potential seawater intrusion and subsequent changes in water quality of the Cm-V aquifer system in the Viimsi peninsula.

The hydrogeological and biogeochemical importance of submarine groundwater inputs has recently been highlighted. Numerous studies around the world have shown that these contributions can challenge fluvial inputs. However, very few studies have been conducted along the French Mediterranean coastline despite the presence of several springs discharging directly into the sea. Submarine groundwater discharge locations were first detected using thermal infrared images. Water and nutrient flux were then estimated using radium isotopes (223Ra, 224Ra and 228Ra). Nutrient inputs are similar (and even greater, up to 20 times higher) to the local river inputs, except the Rhône River. We show that the nutrient fluxes driven by either submarine groundwater discharge (direct inputs of groundwater) or the circulation of seawater through the sediments are significant. These fluxes exist all along the French Mediterranean coastline. This is in contrast with the river inputs which are local inputs. These fluxes need to be considered in the chemical oceanic budgets (coastal seas and likely also in the sea/ocean budgets). These nutrient fluxes may have an impact on the quality of the coastal waters and on the coastal ecosystems; RésuméL’importance hydrogéologique et biogéochimique des apports d’eau souterraine en mer a récemment été mise en évidence. De nombreuses études ont été réalisées à travers le monde, mais très peu ont été menées sur le littoral méditerranéen, malgré la présence de nombreuses résurgences karstiques (Port-Miou, La Palme, Font Estramar…). L’utilisation de l’imagerie infrarouge thermique a permis la détection des décharges d’eau souterraine le long de ce littoral. Les flux d’eau et de nutriments ont ensuite été estimés à l’aide des isotopes du radium (223Ra, 224Ra et 228Ra). Nous montrons que les flux de nutriments associés aux décharges d’eau souterraine et aux flux de circulation d’eau dans les sédiments sont similaires voire supérieurs (jusqu’à 20 fois) aux apports de nutriments associés aux fleuves, à l’exception du Rhône. Nous montrons finalement que les flux associés aux décharges d’eau souterraine en mer et à la circulation de l’eau de mer dans les sédiments ont lieu tout le long du littoral méditerranéen français, à l’inverse des fleuves qui se déchargent ponctuellement. Ces flux sont donc à prendre en compte dans les bilans d’éléments chimiques, nottament à l’échelle régionale (Golfe du Lion).

The hydrogeological and biogeochemical importance of submarine groundwater inputs has recently been highlighted. Numerous studies around the world have shown that these contributions can challenge fluvial inputs. However, very few studies have been conducted along the French Mediterranean coastline despite the presence of several springs discharging directly into the sea. Submarine groundwater discharge locations were first detected using thermal infrared images. Water and nutrient flux were then estimated using radium isotopes (223Ra, 224Ra and 228Ra). Nutrient inputs are similar (and even greater, up to 20 times higher) to the local river inputs, except the Rhône River. We show that the nutrient fluxes driven by either submarine groundwater discharge (direct inputs of groundwater) or the circulation of seawater through the sediments are significant. These fluxes exist all along the French Mediterranean coastline. This is in contrast with the river inputs which are local inputs. These fluxes need to be considered in the chemical oceanic budgets (coastal seas and likely also in the sea/ocean budgets). These nutrient fluxes may have an impact on the quality of the coastal waters and on the coastal ecosystems; RésuméL’importance hydrogéologique et biogéochimique des apports d’eau souterraine en mer a récemment été mise en évidence. De nombreuses études ont été réalisées à travers le monde, mais très peu ont été menées sur le littoral méditerranéen, malgré la présence de nombreuses résurgences karstiques (Port-Miou, La Palme, Font Estramar…). L’utilisation de l’imagerie infrarouge thermique a permis la détection des décharges d’eau souterraine le long de ce littoral. Les flux d’eau et de nutriments ont ensuite été estimés à l’aide des isotopes du radium (223Ra, 224Ra et 228Ra). Nous montrons que les flux de nutriments associés aux décharges d’eau souterraine et aux flux de circulation d’eau dans les sédiments sont similaires voire supérieurs (jusqu’à 20 fois) aux apports de nutriments associés aux fleuves, à l’exception du Rhône. Nous montrons finalement que les flux associés aux décharges d’eau souterraine en mer et à la circulation de l’eau de mer dans les sédiments ont lieu tout le long du littoral méditerranéen français, à l’inverse des fleuves qui se déchargent ponctuellement. Ces flux sont donc à prendre en compte dans les bilans d’éléments chimiques, nottament à l’échelle régionale (Golfe du Lion).

The hydrogeological and biogeochemical importance of submarine groundwater inputs has recently been highlighted. Numerous studies around the world have shown that these contributions can challenge fluvial inputs. However, very few studies have been conducted along the French Mediterranean coastline despite the presence of several springs discharging directly into the sea. Submarine groundwater discharge locations were first detected using thermal infrared images. Water and nutrient flux were then estimated using radium isotopes (223Ra, 224Ra and 228Ra). Nutrient inputs are similar (and even greater, up to 20 times higher) to the local river inputs, except the Rhône River. We show that the nutrient fluxes driven by either submarine groundwater discharge (direct inputs of groundwater) or the circulation of seawater through the sediments are significant. These fluxes exist all along the French Mediterranean coastline. This is in contrast with the river inputs which are local inputs. These fluxes need to be considered in the chemical oceanic budgets (coastal seas and likely also in the sea/ocean budgets). These nutrient fluxes may have an impact on the quality of the coastal waters and on the coastal ecosystems.; L’importance hydrogéologique et biogéochimique des apports d’eau souterraine en mer a récemment été mise en évidence. De nombreuses études ont été réalisées à travers le monde, mais très peu ont été menées sur le littoral méditerranéen, malgré la présence de nombreuses résurgences karstiques (Port-Miou, La Palme, Font Estramar…). L’utilisation de l’imagerie infrarouge thermique a permis la détection des décharges d’eau souterraine le long de ce littoral. Les flux d’eau et de nutriments ont ensuite été estimés à l’aide des isotopes du radium (223Ra, 224Ra et 228Ra). Nous montrons que les flux de nutriments associés aux décharges d’eau souterraine et aux flux de circulation d’eau dans les sédiments sont similaires voire supérieurs (jusqu’à 20 fois) aux apports de nutriments associés aux fleuves, à l’exception du Rhône. Nous montrons finalement que les flux associés aux décharges d’eau souterraine en mer et à la circulation de l’eau de mer dans les sédiments ont lieu tout le long du littoral méditerranéen français, à l’inverse des fleuves qui se déchargent ponctuellement. Ces flux sont donc à prendre en compte dans les bilans d’éléments chimiques, nottament à l’échelle régionale (Golfe du Lion).

The determination of radium isotopes in drinking water by liquid scintillation technique requires some reagents that are used for separating radium from water samples. One of the main reagents is BaCl2·H2O. This paper presents the study of this compound and shows that barium chloride reagent is naturally contaminated with226Ra. The 226Ra activity concentration in BaCl2·H2O reagent produced by chemical companies from Poland and other countries is equal to a few dozen Bq/kg. Furthermore, 14 mL of 0.10 M BaCl2·H2O solution is the optimum amount which should be used for the chemical procedure. At the optimum amount of barium chloride and 2-hour measurement, the detection limit of 226Ra and 228Ra of the liquid scintillation counting method is equal to 5 and 30 mBq per sample, respectively.

International audience; Continental margins play a central role in the composition of seawater by being an important source of trace element essentials to the functioning of the ocean ecosystems. Here, we measured long-lived radium isotopes (Ra-226, Ra-228) along a zonal transect at 12 degrees S (US GEOTRACES GP16) in the eastern tropical South Pacific Ocean. We used Ra-228 to quantify the trace element and isotope (TEI) fluxes (DMn, DFe, and DCo) delivered from the Peruvian continental i) shelf and ii) slope. First, elevated Ra-228 activities were measured in surface water over the entire transect (similar to 8500 km), evidence that the continental shelf is an important source of sediment-derived TEIs not only to coastal areas, but to central Pacific Ocean waters. Modeled Ra-228 shelf fluxes combined with water column dissolved TEI/Ra-228 ratios were used to quantify the shelf-ocean input rates (normalized to shelf-area) for DMn (3.3 x 10(3) mu mol m(-2) y(-1)), DFe (1.5 x 10(3) mu mol m(-2) y(-1)), and DCo (1.0 x 10(2) mu mol m(-2) y(-1)). Second, co-occurring plumes of Ra-228, DFe, and DMn extended over 1800 km from the margin at 1000-2500 m depth, indicative of a continental slope sediment TEI input to the intermediate water column. The Ra-228 gradient allowed us to derive an effective horizontal eddy diffusion coefficient (K-h) of 46 m(2) s(-1), which in turn permitted the calculation of slope sediment DMn (6.4 mu mol m(-2) y(-1)) and DFe (5.9 x 10(2) mu mol m(-2) y(-1)) fluxes based on their offshore concentration gradients. On the scale of the South Pacific continental margin between 0-20 degrees S, the DMn shelf flux is approximately 2-3 orders of magnitude higher than the slope flux, while the DFe shelf/slope flux is similar to 3:1. Both shelf and slope sediment derived DMn was transported over a significant distance towards the ocean interior, while DFe concentration gradients were steep, consistent with longer water column residence time for DMn as compared to DFe in marine systems. These findings highlight the importance of considering the continental slope-ocean boundary in the oceanic budgets of biologically-important trace elements.

To quantify the contribution of submarine groundwater discharge (SGD) to the nutrient budget in tropical embayments, naturally occurring radium isotopes (223Ra, 224Ra, 226Ra, and 228Ra) were investigated as SGD tracers in Sanya Bay, China. Higher activities of radium were present along the north coast and near the Sanya River estuary. Using the activity ratio of 224Ra/228Ra, the apparent water age in Sanya Bay was estimated to be 0–13.2 days, with an average of 7.2 ± 3.2 days. Based on the mass balance of 226Ra and 228Ra, SGD was calculated to be 2.79 ± 1.39–5.07 ± 2.67 × 106 m3 d−1 (or 4.3 ± 2.1–7.8 ± 4.1 cm d−1). SGD associated dissolved inorganic nutrient fluxes into Sanya Bay were estimated to be 3.94 ± 2.00–7.15 ± 3.85 × 105 mol d−1 for oxidized inorganic nitrogen, 4.64 ± 2.74–8.42 ± 5.19 × 103 mol d−1 for phosphate, and 6.63 ± 3.29–12.0 ± 6.34 × 105 mol d−1 for silicate. The estuarine nutrient flux from the Sanya River was a few times smaller than the phosphate flux via SGD and at least an order of magnitude smaller than the oxidized inorganic nitrogen and silicate fluxes carried by SGD. SGD was also more important than atmospheric deposition and nitrogen fixation in the nutrient budget. Our results demonstrate that SGD compensated for at least 15% phosphate, 90% oxidized inorganic nitrogen, and 60% silicate of the nutrients sink in Sanya Bay.

International audience; The circulation of seawater through permeable coastal sediments is increasingly recognized as an important source of nutrients, including dissolved silica (DSi), to the coastal ocean. Here, we utilized a Ra isotope (223 Ra, 224 Ra ex , 228 Ra) mass balance to quantify DSi fluxes driven by water circulation to a small shallow coastal lagoon (La Palme; French Mediter-ranean) during June 2016, as compared to karstic groundwater spring inputs. The DSi flux driven by lagoon water circulation (derived from 224 Ra ex) was approximately one order of magnitude greater (1900 ± 1700 mol d À1) than the DSi load of the karstic groundwater spring (250 ± 50 mol d À1) and greater than molecular diffusion (970 ± 750 mol d À1). Lagoon water circulation was a negligible source of 228 Ra, indicating that circulation-driven DSi inputs occur over a timescale of days. Offshore transects were studied to quantify fluxes of marine-derived submarine groundwater discharge (SGD) from the permeable sandy coastline adjacent to the lagoon, into the Mediterranean Sea. Surface water transects revealed near-shore enrichments of Ra and DSi, attributed to wave-setup and water exchange through the permeable beach between the lagoon and the sea. Upscaling over the 9.5 km stretch of sandy beaches results in a marine SGD-driven DSi flux of 2.3 ± 1.3 Â 10 4 mol d À1 , similar in magnitude to the Têt river during November 2016 (3.3 ± 2.4 Â 10 4 mol d À1), the largest river in the region. A positive relationship between DSi and 224 Ra ex in lagoon water and seawater, but not 228 Ra, suggests that 224 Ra ex and DSi enrichments are derived from a similar source, the sediment (i.e. lithogenic particle dissolution), operating on short timescales. A marine SGD-driven DSi flux to the Gulf of Lions (3.8 ± 2.2 Â 10 5 mol d À1) is likely continuous over time. The relatively constant DSi inputs from water circulation for the shallow lagoons and beaches along the French Mediterranean Sea

Understanding recharge processes and hydrodynamics of karstic systems is an essential rule to assess their vulnerability and their groundwater resource availability. Numerous studies use the behavior of natural geochemical elements and isotopes in groundwaters to improve this understanding. The radium quartet (223Ra, 224Ra, 226Ra and 228Ra) and the radon (222Rn), natural radioactive elements, have been commonly applied for studies devoted to the identification of water mass origins and to their mixing and transfer processes in different type of aquifers. Nevertheless, the applications to karstic systems are mainly concerned to coastal and thermal systems, because of their uncommon Ra enrichment. Just a few works have been undertaken in continental karstic aquifers, probably because of these radionuclide low activities in such environments. This statement makes their quantification not easy and requires large water sampling. The first part of our research work has been devoted to the development of a new sampling system able to pre-concentrate in situ the radium present in several tens of liters of water (20-300 L) with MnO2-fibers and to improve the determination of Ra quartet activities by means of gamma spectrometry. This method gave us the ability of measuring, for the first time, the very low activities of the four radium isotopes (0.4 to < 7.0 mBq/L for 226Ra, 228Ra et 224Ra and from 0.05 to 0.3 mBq/L for 223Ra) in the waters of two Mediterranean karstic hydrosystems, the Haut Vidourle and the Lez systems (both located in South of France). The radon measuring method has also been optimized and improved. The study of the Ra isotope and Rn behavior over the survey area put in evidence the multiple applications of measuring these radionuclides in karstic aquifers. 226Ra activities and (228Ra/ 226Ra) ratios in water are in agreement with the existing lithologies into which the waters flow or are stored. The effective participation of Vidourle river water to the allogenic recharge of the Sauve aquifer has been specified. We showed that sometimes, the Ra isotope activities correspond to characteristic values of the aquifer compartments instead of the bedrock. These data also allow us to estimate the mixing proportions of the three geochemical endmembers composing the waters flowing at the Lez karstic spring in relation with hydrodynamic conditions. Coupling the long-lived radium isotopes (226Ra and 228Ra) together with the short life isotopes (223Ra and 224Ra) potentially led us, at the same time, to determine the mixing rates and the transfer time of the groundwaters. Moreover, the short life isotope excess would express groundwater venues at surface, 223Ra and 224Ra becoming more reliable tracers of superficial exchanges than radon because insensitive to degassing processes towards the atmosphere. On the other end, the study of the radon time evolution at the Lez spring confirmed that this natural radioactive gas is a good tracer of the diffuse recharge processes of karstic aquifers. The relations between 223Ra and 222Rn as well as between 210Pb and 222Rn, could give access to the transfer time of groundwater. However, more exhaustive researches are needed.; La compréhension des processus de recharge et de l’hydrodynamique des systèmes aquifères karstiques est indispensable pour estimer la vulnérabilité et la disponibilité des réserves en eau souterraine. Afin d’améliorer cette compréhension, de nombreuses études ont utilisé l’information issue du comportement de plusieurs éléments chimiques et des isotopes naturels dans les eaux souterraines. Parmi eux, les quatre isotopes du radium (223Ra, 224Ra, 226Ra et 228Ra) et le radon (222Rn), tous radioactifs, sont de plus en plus utilisés. Ces traceurs naturels permettent d’identifier l’origine des différentes masses d’eau et leurs processus de transport et de mélange dans plusieurs types de systèmes aquifères. Cependant, leur application aux systèmes karstiques est principalement développée dans les systèmes côtiers ou thermaux, dont les eaux sont souvent riches en Ra. Très peu de travaux ont été menés dans les aquifères karstiques continentaux, probablement en raison de la faible activité de ces radionucléides, qui les rend difficiles à quantifier et nécessitant le prélèvement de plusieurs litres d’eau. La première partie de ce travail a donc consisté au développement d’un nouveau dispositif de prélèvement capable de concentrer in-situ le radium contenu dans plusieurs dizaines de litres d’eau (20-300 L) à l’aide de de fibre acrylique imprégnée de MnO2 et d’améliorer la mesure des activités par spectrométrie gamma. Grâce à cette méthode, nous avons été capables de mesurer, pour la première fois, les faibles activités des quatre isotopes de Ra (0,4 à < 7,0 mBq/L pour 226Ra, 228Ra et 224Ra et de 0,05 à 0,3 mBq/L pour 223Ra) dans les eaux de deux hydrosystèmes karstiques continentaux Méditerranéens, les systèmes du Haut Vidourle et du Lez (Sud de la France). La méthode de quantification de 222Rn a également été optimisée. L’étude du comportement des isotopes de Ra et de Rn dans la zone d’étude a mis en évidence les diverses applications avérées ou potentielles de la mesure de ces radionucléides dans les aquifères karstiques. En général, les valeurs des activités de 226Ra et du rapport (228Ra/226Ra) des eaux sont cohérentes avec le type de lithologie dans lesquelles elles circulent ou sont stockées. Nous avons pu ainsi mieux préciser l’influence des eaux du Vidourle à la recharge allogénique de l’aquifère de Sauve. Nous avons montré que parfois, les activités des isotopes de Ra correspondent plutôt à des valeurs typiques des différents compartiments aquifères qu’à celles de la roche encaissante. Ces résultats nous ont permis de déterminer les proportions de mélange des trois différents pôles géochimiques composant le flux d’eau qui s’écoule à la source du Lez suivant les conditions hydrodynamiques. Les isotopes à longue période (226Ra et 228Ra) combinés aux isotopes à courte période (224Ra et 223Ra), permettent potentiellement de déterminer, en même temps, les taux de mélange et le temps de transfert des eaux. De plus, l’excès des isotopes à courte période traduirait l’arrivée d’eaux souterraines en surface, 223Ra et 224Ra devenant de meilleurs traceurs des échanges superficiels que Rn car ils ne subissent pas de processus de dégazage vers l’atmosphère. Par contre, l’étude de l’évolution temporelle du radon à la source du Lez a mis en évidence que ce gaz radioactif naturel est un très bon traceur des processus de recharge diffuse des aquifères karstiques. Les relations entre 223Ra et 222Rn, ainsi qu’entre 210Pb et 222Rn, peuvent fournir des informations sur le temps de transfert des eaux souterraines. Cependant, des études complémentaires et à plus long terme sont nécessaires.

International audience; A new portable sampling system was developed to extract Radium isotopes from large volumes (up to 300 L) of fresh surface- and ground-waters of low Ra-activities (

International audience; Study region: The French Mediterranean coastline, which includes karstic springs discharging into coastal seas and coastal lagoons.Study focus: We investigated submarine groundwater discharge (SGD), an important vector for many chemical elements that may impact the quality of the coastal environment. First, we acquired airborne thermal infrared (TIR) images to detect terrestrial groundwater inputs. Then we report in situ data (salinity; temperature; radium isotopes). We use these data i) to confirm the presence of groundwater discharge and to characterize the different systems, and ii) to quantify SGD fluxes and estimate the residence time of the water bodies.New hydrological insights for the region: Few studies have been conducted on SGD along the French Mediterranean coastline. The terrestrial groundwater spring inputs in La Palme and Salses6Leucate coastal lagoons are in the range (0.04-0.11) m(3) s(-1)

International audience; The present study reports data on CO2-rich geothermal waters and their associated carbonate deposits from the SW part of the Permian Lodève Basin (South of France). Both waters and carbonates are enriched in 226Ra, with activities up to 2.2 Bq/L and 3.5 Bq/g respectively. A series of carbonate samples precipitated around the studied wells since 1990 were dated through the 226Ra-210Pb and 228Ra-228Th methods, and the results are discussed in a new Concordia diagram. While both methods give comparable dates for many samples, Ra-Pb ages are sometimes much older than Ra-Th ages. We propose that these discrepancies result from the adsorption of 222Rn daughter nuclides in such a Rn-rich environment. The (228Ra/226Ra)0 activity ratios calculated at the time of deposition are remarkably constant for about 12 years, suggesting the presence of a steady-state aquifer. The low (228Ra/226Ra)0 ratios (0.348 ± 0.008) are best explained if most of the Ra derives from the Cambrian carbonate series (mainly dolostone) underlying the Permian Basin, which have low Th/U and similar (228Ra/226Ra) ratios. This study suggests that Ra and other alkaline-earth elements do not necessarily originate from the rocks surrounding the deep geothermal reservoir, but rather may be introduced into the CO2-rich water during its transfer towards the surface and interaction with carbonate rocks.

International audience; Radium quartet (226Ra, 228Ra, 224Ra and 223Ra) is largely used in coastal karstic systems astracer of fresh- and sea-water interactions. Ra isotopes have also been applied to the study of waterrock interactions, residence times and mixing of different waters in geothermal systems orgroundwaters. The aims of this work were i) to study the relationship between the (228Ra/226Ra)activity ratios and the lithologies through which the water is flowing (especially their Th/U ratios) in theVidourle River, because it drains terranes from the crystalline basement of the Cévennes to theMesozoic marl and calcareous series with sinkholes resurgences and karstic tributaries. ii) to monitorthe time variation of Ra quartet in karstic springs emerging through the Mesozoic limestones near theLez spring, and to decipher how the activities of these isotopes are linked to mixing of different waters,and to the hydrodynamic conditions. Ra quartet was measured simultaneously by gammaspectrometry, using a new system for in situ sampling of large amounts of water with low Ra activities(typically 1 to 4 mBq/L). A general decrease of the (228Ra 226Ra) ratios (from 1.4 to 0.9) and of the(226Ra) activities along the Vidourle River is in agreement with the transition from U -rich rocks of thecrystalline basement with high Th U ratios, to mainly calcareous Mesozoic rocks with lower U contentsand low Th/U ratios. The four karstic springs of the Lez area display lower (228Ra/226Ra) ratios (0.5to 0.7), but (226Ra) activities similar to those found in the Vidourle. These lower ratios are probablyrelated to the low Th U ratios of the Upper-Jurassic Lower Cretaceous limestones through which thekarst system has developed. Significant temporal variations of this ratio at the Lez spring show theparticipation of different water masses according to the hydrodynamics. Short-lived Ra isotopes areparticularly influenced by water-rock interactions (with alpha-recoil processes) in the epikarstic zone.

11 pages, 8 figures, 3 tables, Submarine groundwater discharge (SGD) was investigated at El Gorguel Bay (Cartagena-La Unión Pb–Zn mining district, Murcia, Spain), a Mediterranean region where mine tailings have been accumulated for decades at the shoreline. At this site, groundwater may become enriched in metals prior to discharge to the coastal sea and may lead to significant releases that can contaminate the coastal environment. The distribution of dissolved metals and Ra isotopes were studied in seawater and groundwater samples collected during the summer season in 2013. Cross-shore gradients of 224Ra in the bay allowed the calculation of a SGD flow of (39 ± 14) 103 m3 day−1. SGD-driven metal fluxes were 47–180 mol day−1 km− 1 for Zn, 0.20–0.60 mol day− 1 km− 1 for Pb, 4–32 mol day− 1 km− 1 for Fe, 0.8–2.3 mol day− 1 km− 1 for Cu and 0.9–2.8 mol day− 1 km− 1 for Ni. Compared to other coastal zones not affected by mining activities, SGD-driven metal fluxes were especially significant for dissolved Zn and Pb. The magnitude of these SGD-driven metal fluxes indicates that SGD is a relevant pathway in delivering metals to the coastal environment at El Gorguel Bay. This fact highlights the importance of investigating the role of SGD as a possible source of contamination to the sea in mining districts located in the proximity of the coast., This project has been partially funded by the European Union Seventh Framework Programme, Marie Curie Actions, through the MetTrans Initial Training Network, which also provide financial support through a PhD fellowship to G.T. (EU FP7-People-2011-ITN-290336). The research has been funded partially also by the Spanish Government project NUREIEV (CTM2013-44598-R). Support from the CSIC, under the program JAE-Doc (Junta para la Ampliación de Estudios) co-funded by the Fondo Social Europeo (FSE) is acknowledged for the post-doctoral fellowship (JAEDOC038) to J.S.-E. V.R. was supported through a Ph.D. fellowship (AP2008-03044) from the Spanish Government. A Beatriu de Pinós Postdoctoral fellowship from the Generalitat de Catalunya (2011BP-B00225) and a post-doctoral grant (FPDI-2013-15660) from the Spanish Government to E.G.-S. are also acknowledged. P.M. was supported in part by a Gledden Visiting Fellowship awarded by the Institute of Advanced Studies at The University of Western Australia. The support of the Generalitat de Catalunya to MERS (2014 SGR — 1356) is also acknowledged.

The hyperfine structure of short-lived trapped Ra-211,209(+) ions was investigated by means of laser spectroscopy. The hyperfine structure constants A and B of the 6d(2)D(3/2) level were determined. There is a 2.2 standard deviation difference between the theoretical and the more accurate experimental value for the B coefficient of Ra-211(+). These measurements provide a test for the atomic theory required for upcoming experiments on atomic parity violation and atomic clocks. (C) 2011 Elsevier B.V. All rights reserved.

The hyperfine structure of short-lived trapped Ra-211,209(+) ions was investigated by means of laser spectroscopy. The hyperfine structure constants A and B of the 6d(2)D(3/2) level were determined. There is a 2.2 standard deviation difference between the theoretical and the more accurate experimental value for the B coefficient of Ra-211(+). These measurements provide a test for the atomic theory required for upcoming experiments on atomic parity violation and atomic clocks. (C) 2011 Elsevier B.V. All rights reserved.

The hyperfine structure of short-lived trapped Ra-211,209(+) ions was investigated by means of laser spectroscopy. The hyperfine structure constants A and B of the 6d(2)D(3/2) level were determined. There is a 2.2 standard deviation difference between the theoretical and the more accurate experimental value for the B coefficient of Ra-211(+). These measurements provide a test for the atomic theory required for upcoming experiments on atomic parity violation and atomic clocks. (C) 2011 Elsevier B.V. All rights reserved.

The hyperfine structure of short-lived trapped Ra-211,209(+) ions was investigated by means of laser spectroscopy. The hyperfine structure constants A and B of the 6d(2)D(3/2) level were determined. There is a 2.2 standard deviation difference between the theoretical and the more accurate experimental value for the B coefficient of Ra-211(+). These measurements provide a test for the atomic theory required for upcoming experiments on atomic parity violation and atomic clocks. (C) 2011 Elsevier B.V. All rights reserved.

The four naturally-occurring radium isotopes (223Ra, 224Ra, 226Ra and 228Ra) were used to estimate the submarine groundwater discharge (SGD) in the Isola La Cura marsh area in the northern Venice Lagoon (Italy). By determining the radium contributors to the study area (river, coastal ocean and sediments) the radium excess in the lagoon water was quantified through a mass balance model. This radium excess is attributed to a submarine groundwater discharge source and represents the most important input of radium. Possible endmembers were considered from analysis of groundwater samples (subtidal and marsh piezometers, marsh wells and seepage meters) that were enriched in Ra by one to two orders of magnitude relative to surface waters. In particular, a permeable layer at 80 cm depth in the surrounding marsh is considered to be representative of the most likely SGD source, although similar radium activities were measured in other subtidal porewater samples collected in the Isola La Cura area. The estimated SGD flux to the study area ranged from 1 · 109 to 6 · 109 L·d− 1, the same order of magnitude as the overall riverine input to the lagoon (3 · 109 L·d− 1). A major fraction of this SGD flux is likely recirculated seawater, as evidenced by the endmember salinity. The water residence time of 2 days was estimated by both using the shortest-lived radium isotope and estimating the volume of water exchanged between the lagoon and the open sea during a tidal cycle (tidal prism approach). This SGD flux could be used to estimate the input of other chemical species (metals, nutrients, etc.) via SGD which might affect the Venice Lagoon ecosystem.

The mixing rate of dissolved substances from the Yellow River into the Bohai Sea is an important parameter in understanding the nutrient input to the coastal ocean. We present an assessment of the mixing rates under different discharge patterns using naturally-occurring short-lived radium isotopes. Radium and salinity measurements were collected along transects through the Yellow River salinity gradient and into the coastal Bohai Sea during three field expeditions. Mixing rates varied between 5 and 18 km2/day and were strongly dependent on river discharge. The highest mixing rates are found just after periods of high discharge, while the lowest mixing rates occurred after periods of relatively low discharge.

Bu çalışmada, In this Study

WOS: 000352928600006, We systematically investigate the influence of nuclear deformations of the cluster and daughter nuclei on the half-lives of He-4, Be-8,Be-10, C-12,C-14,C-16 and O-16,O-18,O-20,O-22 cluster decays from Ra210-226. The Wentzel-Kramers-Brillouin (WKB) method and Bohr-Sommerfeld quantization condition with the deformed squared Woods-Saxon and Cosh potentials are used phenomenologically in order to compute the half-lives. The calculations are performed for the spherical cluster and deformed daughter, deformed cluster and spherical daughter and deformed cluster and daughter cases. The half-lives for different orientation angles as well as over all angles are calculated, in order to show the deformation effects on the systems. In cases where the deformation of both cluster and daughter effect the result, it is found that the deformation of the cluster is more important than the deformation of the daughter. Furthermore, it is also found that taking into account the orientation angles of the daughter and cluster also improves the results when compared to experiment. However, the results for a Cosh potential with certain parameters without any deformation are found to be more compatible with both the results obtained by the Coulomb and proximity potential model (CPPM) and the universal formula for cluster decay (UNIV), as well as the experimental values for He-4 and C-14 decays. The results provide a useful method for estimating the unknown experimental half-lives of possible exotic decays from Ra isotopes. (C) 2015 Elsevier B.V. All rights reserved., Turkish Science and Research Council (TUBITAK) [113F225], This work was partly supported by the Turkish Science and Research Council (TUBITAK) with Grant No. 113F225. Authors would like to thank Dr. Neil Curtis for the proofreading.

© 2015 Elsevier B.V. The influence of sediments on the determination of SGD by using Ra isotopes was investigated in the Port of Maó (Balearic Islands, NW Mediterranean). This natural harbor was selected because SGD occurs all along its southern boundary and it is covered by fine-grained sediments that are frequently resuspended due to vessel maneuvering. Comprehensive seasonal Ra mass balances were constructed for the waters of the Port of Maó using both short-lived (224Ra) and long-lived (228Ra) Ra isotopes. SGD flows to the Port of Maó obtained by using 228Ra revealed a seasonal pattern, likely dominated by the recharge cycle, with maximum SGD rates during the wet seasons ((180±100)·103m3·day-1 in fall) and minimum flows during summer ((56±35)·103m3·day-1). The results also showed that the Ra flux from bottom sediments, through diffusion and due to releases associated to resuspension events, represented a significant source of Ra to the harbor waters. This sedimentary source accounted for a major fraction of the 224Ra supplied to the system (30-90%, depending on the season), whereas the sediment influence on the 228Ra mass balance was significantly lower (10-40%) due to its slower production rate. These findings suggested that attributing Ra inputs to the water column solely to SGD in systems covered by fine-grained sediments and/or affected by processes that favor Ra exchange across the sediment-water interface might not be accurate, requiring a detailed evaluation of the sediment sources. The inputs from sediments are often difficult to quantify, but using long-lived Ra isotopes to estimate the SGD flow may minimize the effect of a poor characterization of the sediment source., This project has been partially funded by the Spanish Government Project EHRE (ref. CTM2009-08270). V.R. acknowledges financial support through a PhD fellowship (AP2008-03044) from MICINN (Spain). Authors want to thank the support of the Generalitat de Catalunya to MERS (2014 SGR-1356). Support for the research of P.M. was received through the prize ICREA Academia, funded by the Generalitat de Catalunya and by a Gledden Visiting Fellowship awarded by the Institute of Advanced Studies at the University ofWestern Australia

The impact on local water resources due to fly ash produced in the Koradi and Khaperkheda thermal power plants (district of Nagpur, Maharashtra- India) and disposed in large ponds at the surfacewas assessed through the study of environmental variation of ratios of stable and unstable isotopes. Analyses of oxygen and hydrogen isotopes suggest scarce interaction between the water temporarily stored in the ponds and the groundwater in the study area. Data also highlight that the high salinity of groundwater measured in the polluted wells is not due to evaporation, but to subsequent infiltration of stream waters draining from the ponds to the local aquifer. Sr-87/Sr-86 values, when associatedwith Sr/Ca ratios, demonstrate the dominant role ofwastewaters coming from tens of brick kilns surrounding the pond sulfate pollution. Uraniumisotopic analyses clearly showevidence of the interaction between groundwater and aquifer rocks, and confirm again the low influence of ash ponds. A new conceptual model based on the study of the isotopes of radium is also proposed and used to estimate residence times of groundwater in the area. This model highlights that high salinity cannot be in any case attributed to a prolonged water-rock interaction, but is due to the influence of untreated waste water of domestic or brick kiln origin on the shallow and vulnerable aquifers. (C) 2015 Elsevier B.V. All rights reserved.

The Euganean Geothermal Field (EGF) extends on a plain band of 36 km² in the north eastern Italy nearVenice. Thermal waters (65°C to 86°C) are exploited from about 250 wells for a total flow rate of 17 Mm³/y.The Euganean thermal waters are of meteoric origin and infiltrate 80 km to the north of the EGF in the Venetopre-Alps. The geothermal reservoir is situated at a depth of 3 km in Mesozoic carbonate formations, whilethe regional Schio-Vicenza fault system and its permeable damage zone enhance the thermal fluid flow in thesubsurface. In the EGF area, the hot waters intercept an interaction zone between faults of the fault systemand rise quickly to the surface through the local fracture mesh. In order to constraint the upwelling timeof this thermal water from the deep reservoir, an isotopic study on stable (oxygen, hydrogen, carbon) andradioactive isotopes (radium, radon, actinium) has been carried out. In this paper we will report on the resultsof the radioactive isotopes.

Submarine Groundwater Discharge (SGD) from a detrital coastal aquifer into the adjacent marine environment was investigated in a Mediterranean bay (Palma Beach, Balearic Islands). In this region, agriculture and tourism are potential sources of groundwater contamination. A survey in the Palma Beach revealed N, Fe and chlorophyll a enhancement associated to areas of preferential groundwater discharge from the nearby coastal aquifer. Groundwater sampling from wells and coastal piezometers indicated high concentrations of dissolved inorganic nitrogen and Fe (up to 2800μmolL-1 and 8100nmolL-1, respectively). Other nutrients, such as DIP, and trace elements were not particularly elevated, which is attributed to the adsorptive characteristics of the carbonated composition of this detrital aquifer and/or the lack of major sources. Cross-shore gradients of 223,224,226Ra isotopes indicated a diffusive shore-based source of these radionuclides and allowed estimates of a SGD flow of 56,000±13,000m3d-1. Our results show that SGD is a major pathway for delivering DIN (1900mmolm-1d-1), dissolved Fe (4.1mmolm-1d-1) and, to a lesser extent, DIP (16mmolm-1d-1) into the nearshore waters. This allochthonous input may sustain a substantial phytoplankton biomass resulting in an onshore-offshore gradient (4.7-7.1mgm-3 in nearshore seawater as compared with, This project has been funded partially by the Spanish Government projects EDASE (ref. CGL2008-00047/BTE) and GRADIENTS (CTM2012-39476-C02-01). V.R. acknowledges financial support through a PhD fellowship (AP2008-03044) from MICINN (Spain). Support from a post-doctoral fellowship to E.G.-S. (EX2009-0651; Plan Nacional de I-D+i 2008–2011, Spain) is acknowledged. Support for the research of P.M. was received through the prize ICREA Academia, funded by the Generalitat de Catalunya.

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Moreno, Victoria Garcia-Solsona, Ester Masque, Pere Masque, Pere/B-7379-2008 Masque, Pere/0000-0002-1789-320X Spanish Government project EDASMAR [CGL2006-09274/HID]; Consejo de Seguridad Nuclear project [2686-SRA]; MICINN (Spain) [AP2008-03044]; ICREA Academia; Generalitat de Catalunya The authors would like to thank the assistance in field and laboratory work from our colleagues at the Laboratori de Radioactivitat Ambiental (Universitat de Barcelona). This project has been funded partially by the Spanish Government project EDASMAR (Ref. CGL2006-09274/HID) and the Consejo de Seguridad Nuclear project (Ref. 2686-SRA). V.R. acknowledges financial support through a PhD fellowship (AP2008-03044) from MICINN (Spain). Support for the research of PM was received through the prize ICREA Academia, funded by the Generalitat de Catalunya. We also want to thank the collaboration of Anna Cherta, Maribel Forner (Hotel Marina), Camping Eden, FACSA, School "Jaume Sainz" and the Peniscola Municipality. We want also to thank Gerard Carmona and Lluis Benejam for their support during fish sampling. 1 ELSEVIER SCIENCE BV AMSTERDAM MAR CHEM SI; Submarine groundwater discharge (SGD) has attracted the interest from the scientific community over the past decade for its impact on biogeochemical cycles of coastal ecosystems and/or management of water resources. SGD is associated with a flow of natural radionuclides (Ra isotopes and Rn-222), which are often used as SGD tracers that can significantly increase the natural background radiation. Although in many circumstances the discharge is produced directly to the sea and therefore the increase of natural radioactivity levels can generally be considered negligible due to a dilution processes, the discharge into coastal wetlands (marshes, coastal lagoons or ponds), with somewhat restricted exchange with the open sea, may require a detailed study of the distribution of natural radionuclides and their effects on the coastal ecosystem. The Peniscola marsh is a Mediterranean coastal wetland where such studies may be of special interest because it is fed exclusively by groundwater, mainly discharging from a deep aquifer with high natural radioactivity content. In the Peniscola marsh, brackish groundwater discharging through the wetland sediments is enriched in radionuclides to maximum values of 2.8 and 616 kBq m(-3) of Ra-226 and Rn-222, respectively. These high dissolved concentrations result in high levels of Rn-222 in air (up to 36 Bq m(-3)) and Pb-210 and Po-210 dissolved in water (20 and 5.7 Bq m(-3), respectively). These elevated levels of natural radionuclides in the Peniscola marsh are also responsible of the significant increase in Po-210 and Pb-210 contents in both fish and plants. (C) 2013 Elsevier B.V. All rights reserved.

The behaviour of the four Ra isotopes (measured by gamma spectrometry) and 222 Rn (measured with an AlphaGUARD ionisation chamber) has been investigated in NaCl-rich thermal waters of Balaruc-les-Bains on the Mediterranean coast (South of France). This study allows identification of the deep thermal water signature and reveals the influence of seawater or karst water inflows on Ra isotopes and 222 Rn. The deep thermal water has 226 Ra and 222 Rn activities of 840 and 1900 mBq/l, respectively, a ( 228 Ra/ 226 Ra) activity ratio of 0.59, and low ( 224 Ra/ 228 Ra) and ( 223 Ra/ 226 Ra) ratios of 0.67 and 0.025, respectively. Several arguments suggest a dominant role of radioactive decay for short-lived Ra isotopes and Rn during the relatively rapid ascent of thermal water through wide open fractures and drains. The low ( 223 Ra/ 226 Ra) ratio constrains the maximum ascent velocity of thermal water to 8–10 m/h. Seawater inflow into the hydrothermal system results in an enrichment in short-lived Ra isotopes and 222 Rn. The high ( 223 Ra/ 226 Ra) ratio (0.23) suggests that 223 Ra, 224 Ra and 222 Rn produced by alpha-recoil in the upper-Jurassic limestone are entrained by seawater percolation through the coastal basement, due to active pumping in one of the near shore production well. This process would be enhanced by a low water/rock ratio (i.e. in a low-porosity, micro-fractured limestone). Mixing of this enriched seawater with thermal water induces barite precipitation with co-precipitation of a large fraction of Ra. Short-lived Ra isotopes may thus be useful tracers of seawater flux towards the continent. Conversely, the inflow and mixing of karst groundwater result in a general dilution of all dissolved elements, only a small enrichment in 224 Ra and 223 Ra, but a large enrichment in 222 Rn (up to 26 Bq/l). The combination of Ra isotopes and 222 Rn data provides a good way to trace the dynamics of different water masses along coastal areas.

International audience; Studies of submarine groundwater discharge (SGD) have been focused on passive margins with large floodplains [1]. SGD from active margins without substantial sediment cover remains unknown, but it is in the rapidly eroding highlands along these margins that the feedback between climate and weathering is most effective [2].In Taiwan, measured erosion and silicate weathering rates are amongst the highest in the world. In a representative section of the northeast coast of Taiwan, at the outlet of the Liwu river, we have explored the possible magnitude and pattern of SGD, and its implications for weathering budgets. The river drains 4 km of emergent mountain relief, with a further 5 km of submarine relief above the Pacific abyssal plain. In the Liwu catchment, 16±1% of the river discharge (averaged over 37 years of record) comes from a deep groundwater reservoir, and deep seated chemical weathering of silicates accounts for 38% of the riverine silicate weathering flux [3]. It is likely that the large inland hydraulic head drives submarine discharge from this deep groundwater reservoir and weathering reactor.We have used the radium quartet (228Ra, 226Ra, 224Ra, 223Ra) along with Temperature-Salinity (T-S) profiles on two 50 km West- East marine transects off the NE coast of Taiwan (

A multiproxy approach of complementary techniques is applied to localise and quantify submarine groundwater discharge (SGD) from El Maestrazgo Jurassic aquifer, an example of widespread carbonate coastal aquifer of the Western Mediterranean Sea (Castellón, Spain). Unconventional water resources are critical in this area where highly populated resorts have been developed. The aquifer has two main features of particular interest: a karstic system with a deep saturated zone reaching 450 m and with no significant surface discharge occurring within the continental area. On the other hand, SGD can alter the condition of coastal marine environments, reducing salinities and providing nutrients that can cause eutrophication and algal blooms. The applied combined techniques make it possible to detect groundwater outflows using airborne thermal infrared (TIR) images to monitor physico-chemical anomalies in the sea and to quantify the submarine groundwater discharges by means of direct measurements and radium isotopic analyses. Three main coastal areas affected by SGD and a submarine spring located at 3 km from the coast, which seems to be associated with tectonic discontinuities, were localised. The calculated fresh SGD from Ra isotopes, 375 Mm3 y−1, is in agreement with the mean aquifer recharge obtained by hydrogeological methods, 394 Mm3 y−1., Instituto Geológico y Minero de España, España, Institut de Ciència i Tecnologia Ambientals, Universitat Autònoma de Barcelona, España, Departament de Física, Universitat Autònoma de Barcelona, España, Laboratoire d’Etudes en Géophysique et Océanographie Spatiales, Francia

Made available in DSpace on 2014-10-09T12:32:58Z (GMT). No. of bitstreams: 0 Made available in DSpace on 2014-10-09T14:06:11Z (GMT). No. of bitstreams: 0 Cogumelos s??o esp??cies de fungos que t??m a capacidade de reter radionucl??deos e elementos est??veis, importantes do ponto de vista t??xicol??gico e radiol??gico do meio ambiente. Estudos t??m demonstrado que cogumelos podem ser utilizados como bioacumuladores na monitora????o e na avalia????o de contamina????o e qualidade do ecossistema. No presente estudo, foram determinados os radionucl??deos 226Ra, 228Ra, 210Pb e os elementos As, Co, Cr, Cs, Fe, K, La, Mn, Na, Sc, U, Th e Zn em 24 amostras de cogumelos e de solos coletadas na regi??o do Planalto de Po??os de Caldas. O Planalto de Po??os de Caldas ?? um exemplo de regi??o de anomalia radioativa, apresentando cerca de 70 delas. No presente estudo, dois grupos de amostragem (do total de sete grupos) foram realizados em locais que apresentam tais anomalias. A determina????o dos elementos est??veis foi realizada por An??lise por Ativa????o com N??utrons. As determina????es de 226Ra, 228Ra e 210Pb nas amostras de cogumelos foram realizadas por separa????o radioqu??mica e suas atividades foram quantificadas em contador proporcional de fluxo gasoso Alfa e Beta Total. A determina????o destes mesmos radionucl??deos nos solos foi realizada por Espectrometria Gama. A determina????o dos is??topos de t??rio nos cogumelos foi realizada por separa????o radioqu??mica e quantificada por Espectrometria Alfa. O controle anal??tico de todas as metodologias utilizadas no presente trabalho foi realizado com o uso de materiais de refer??ncia certificados. Foram tamb??m analisadas amostras de cogumelos de uma regi??o que n??o apresenta anomalia radioativa e os resultados comparados com os valores obtidos no Planalto de Po??os de Caldas, podendo assim comprovar que cogumelos atuam como indicadores de contamina????o radioativa do meio ambiente. As concentra????es e atividades mais elevadas foram encontradas nas amostras coletadas nas zonas rurais do Planalto de Po??os de Caldas, onde ocorrem as maiores anomalias radioativas na regi??o. Pelos resultados obtidos, pode-se comprovar a efici??ncia do cogumelo como indicador de contamina????o radioativa ambiental, sendo estes apropriados para avaliar os n??veis de radioatividade em ??reas de Materiais Radioativos de Ocorr??ncia Natural. Disserta????o (Mestrado) IPEN/D Instituto de Pesquisas Energeticas e Nucleares - IPEN-CNEN/SP

Groundwater discharge constitutes the main water inflow of many coastal wetlands. Despite the potential of Ra isotopes and 222Rn as tracers of groundwater discharge, the use of these radionuclides to quantify the groundwater inflow in coastal wetlands has been only scarcely addressed in the literature. The main goal of this study is to evaluate the use of 222Rn and Ra isotopes to estimate the contribution of distinct groundwater sources into a Mediterranean coastal wetland (the Peníscola marsh, Castelló, Spain). The Peníscola marsh is a small shallow wetland nourished by groundwater coming from four different flowpaths: (i) a deep flow from the regional carbonate aquifer of El Maestrat, (ii) a shallow flow and (iii) an intermediate flow, both from the Irta Range and the detritic Vinaròs-Peníscola aquifer, and (iv) seawater intrusion. Data on 226Ra, 222Rn and salinity obtained in summer 2007 revealed that the deep groundwater contribution was 15% of the total water inflow, whereas the shallow and intermediate flow paths represented 32% and 48%, respectively. Seawater accounted only for the remaining 5% inputs to the wetland. Ra isotopes also allowed estimating the marsh water age in 1.2 days. Both the groundwater contributions derived from 222Rn measurements and the Ra-derived marsh water age agreed well with the direct measurements obtained using propeller flow meters, evidencing the effectiveness of the used methods. An interannual comparison between the estimated groundwater inflow and the precipitation revealed that shallow groundwater flows respond to local precipitation, whereas the deep groundwater flow from the carbonate aquifer is dominated by a constant baseflow, Institut de Ciència i Tecnologia Ambientals, Universitat Autònoma de Barcelona, España, Departament de Física, Universitat Autònoma de Barcelona, España, Laboratoire d’Etudes en Géophysique et Océanographie Spatiales, Francia, Instituto Geológico y Minero de España, España, Departament de Geologia, Universitat Autònoma de Barcelona, España

The hyperfine structure of short-lived trapped Ra-211,209(+) ions was investigated by means of laser spectroscopy. The hyperfine structure constants A and B of the 6d(2)D(3/2) level were determined. There is a 2.2 standard deviation difference between the theoretical and the more accurate experimental value for the B coefficient of Ra-211(+). These measurements provide a test for the atomic theory required for upcoming experiments on atomic parity violation and atomic clocks. (C) 2011 Elsevier B.V. All rights reserved.

The hyperfine structure of short-lived trapped Ra-211,209(+) ions was investigated by means of laser spectroscopy. The hyperfine structure constants A and B of the 6d(2)D(3/2) level were determined. There is a 2.2 standard deviation difference between the theoretical and the more accurate experimental value for the B coefficient of Ra-211(+). These measurements provide a test for the atomic theory required for upcoming experiments on atomic parity violation and atomic clocks. (C) 2011 Elsevier B.V. All rights reserved.