|   | 
Details
   web
Records
Author Musy, S.; Purtschert, R.
Title Reviewing 39Ar and 37Ar underground production in shallow depths with implications for groundwater dating Type Journal Article
Year 2023 Publication Science of The Total Environment Abbreviated Journal
Volume 884 Issue Pages 163868
Keywords Subsurface production, Argon-39, Argon-37, Muons, Isotope hydrology, Tracers
Abstract Argon-37 (37Ar) and Argon-39 (39Ar) are used for groundwater dating on timescales from weeks to centuries. For both isotopes, the quantification of underground sources is essential to accurately infer water residence times from sampled dissolved activities. Subsurface production resulting from interactions with neutrons from the natural radioactivity in rocks and with primary cosmogenic neutrons has been known for a long time. More recently, the capture of slow negative muons and reactions with muon-induced neutrons were documented for 39Ar subsurface production in the context of underground particle detectors (e.g. for Dark Matter research). However, the contribution from these particles was never considered for groundwater dating applications. Here, we reevaluate the importance of all potential depth-related production channels at depth ranges relevant for 39Ar groundwater dating [0 − 200 meters below the surface (m.b.s)]. The production of radioargon by muon-induced processes is considered in this depth range for the first time. The uncertainty on the total depth-dependent production rate is estimated with Monte Carlo simulations assuming a uniform distribution of the parameter uncertainties. This work aims to provide a comprehensive framework for interpreting 39Ar activities in terms of groundwater residence times and for exposure age dating of rocks. The production of 37Ar is also addressed since this isotope is relevant as a proxy for 39Ar production, for the timing of river-groundwater exchanges, and in the context of on-site inspections (OSI) within the verification framework of the Comprehensive Nuclear-Test-Ban Treaty (CTBT). In this perspective, we provide an interactive web-based application for the calculation of 37Ar and 39Ar production rates in rocks.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0048-9697 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number (down) THL @ christoph.kuells @ Musy2023163868 Serial 217
Permanent link to this record
 

 
Author Musy, S.; Meyzonnat, G.; Barbecot, F.; Hunkeler, D.; Sültenfuss, J.; Solomon, D.K.; Purtschert, R.
Title In-situ sampling for krypton-85 groundwater dating Type Journal Article
Year 2021 Publication Journal of Hydrology X Abbreviated Journal
Volume 11 Issue Pages 100075
Keywords Noble gases, Tracers, Groundwater, Dating, Sampling Methodology
Abstract Krypton-85 and other radioactive noble gases are widely used for groundwater dating purposes. 85Kr analysis require large volumes of water to reach the analytical requirements. Conventionally, this water is pumped to the surface to be degassed with a gas extraction system. The large pumping rate may disturb the natural flow field and requires substantial field logistics. Hence, we propose a new in-situ degassing method, in which membrane contactors are used to degas the groundwater directly in the well and gas is collected at the surface. This way, field work is facilitated, groundwater system disturbance is minimized, and the gas sample is collected at a specific depth. We demonstrate the tightness of the system regarding atmospheric air contamination for a collection times of 24 h, which is sufficient for both low-level counting and laser-based counting methods for 85Kr. The minimal borehole diameter is 7.5 cm for the prototype presented in this research but can easily be reduced to smaller diameters. In a case study, we compare the results obtained with the new passive method with those from a conventional packer setup sampling. Additionally, 3H/3He samples were collected for both sampling regimes and the dating results were compared with those from 85Kr. A good agreement between tracer ages is demonstrated and the age stratigraphy is consistent with the expected age distribution for a porous unconfined aquifer. In addition, our study emphasizes the differences between the age information sampled with various methods. In conclusion, we demonstrate that the new in situ quasi-passive method provides a more representative age stratigraphy with depth in most cases.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2589-9155 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number (down) THL @ christoph.kuells @ Musy2021100075 Serial 215
Permanent link to this record
 

 
Author Puri, S.
Title Chapter 9 – Transboundary aquifers: a shared subsurface asset, in urgent need of sound governance Type Book Chapter
Year 2021 Publication Global Groundwater Abbreviated Journal
Volume Issue Pages 113-128
Keywords ILC Draft Articles, impact on GDP, sound governance, Transboundary aquifers
Abstract Apart from some notable exceptions, the sound governance of transboundary aquifers (coupled or uncoupled to rivers) is seriously lacking in most regions of the world, despite a highly successful 20-year ISARM initiative. The distinction between regions of water abundance (as in the Haute Savoie–Geneva aquifers) and those of water scarcity (\textless1000 m3/an/capita), as in the Rum-Saq aquifer, ought to be a driver for the urgency in adopting sound governance. In the latter regions, however, such an urgent response faces too many hurdles (institutional, financial, and weak capacity). Climate change, one of the global megatrends (among demography, economic shift, resources stress, urbanization, and novel viruses such as COVID-19), will exacerbate the problem in the coming decade and beyond. This chapter provides an critical perspective on the status of this subsurface asset in 570 or so, domestic and transboundary aquifers of the world (self-identified by country experts), while taking full account of their interconnections, or not, with surface waters. This critical perspective will be grounded in two important factors, first the hiatus in adoption by countries of the evolving international water law and guidance on transboundary aquifers (the Draft Articles, which provide legal pathways for collaboration or eventually dispute resolution), and second the framework of the sustainable development goals (SDG) 6 (clean water and sanitation), which countries have committed themselves to with reference to transboundary waters. The critical perspective finds that despite the lack of momentum in adopting formal global norms, sporadic cooperation and collaboration is continuing and is well received, when delivered methodically through the support of international agencies. The findings of the critical perspective are that even if water-related SDGs will have been achieved across the world, it would contribute precious little to meaningful enhancement of governance of transboundary aquifers, unless they have been explicitly addressed in terms that are tangible to decision makers, such as the impact of disregarding them on the current or future national GDP. The onset of a “new socioeconomic normal” in the aftermath of COVID-19 could further defer meaningful progress, taking the example of Latin America, where a 5% decline has been forecast for 2020. With such declines in the finances of governments, attention to shared aquifer resources may well decline even further. Urgent wise reaction to this possibility must be a priority for the professional science-policy community.
Address
Corporate Author Thesis
Publisher Elsevier Place of Publication Editor Mukherjee, A.; Scanlon, B.R.; Aureli, A.; Langan, S.; Guo, H.; McKenzie, A.A.
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN ISBN 978-0-12-818172-0 Medium
Area Expedition Conference
Notes Approved no
Call Number (down) THL @ christoph.kuells @ mukherjee_chapter_2021 Serial 106
Permanent link to this record
 

 
Author Mühr-Ebert, E.L.; Wagner, F.; Walther, C.
Title Speciation of uranium: Compilation of a thermodynamic database and its experimental evaluation using different analytical techniques Type Journal Article
Year 2019 Publication Applied Geochemistry Abbreviated Journal
Volume 100 Issue Pages 213-222
Keywords
Abstract Environmental hazards are caused by uranium mining legacies and enhanced radioactivity in utilized groundwater and surface water resources. Knowledge of uranium speciation in these waters is essential for predicting radionuclide migration and for installing effective water purification technology. The validity of the thermodynamic data for the environmental media affected by uranium mining legacies is of utmost importance. Therefore, a comprehensive and consistent database was established according to current knowledge. The uranium data included in the database is based on the NEA TDB (Guillaumont et al., 2003) and is modified or supplemented as necessary e.g. for calcium and magnesium uranyl carbonates. The specific ion interaction theory (Brönsted, 1922) is used to estimate activity constants, which is sufficient for the considered low ionic strengths. The success of this approach was evaluated by comparative experimental investigations and model calculations (PHREEQC (Parkhurst and Appelo, 1999)) for several model systems. The waters differ in pH (2.7–9.8), uranium concentration (10−9-10−4 mol/L) and ionic strength (0.002–0.2 mol/L). We used chemical extraction experiments, ESI-Orbitrap-MS and time-resolved laser-induced fluorescence spectroscopy (TRLFS) to measure the uranium speciation. The latter method is nonintrusive and therefore does not change the chemical composition of the investigated waters. This is very important, because any change of the system under study may also change the speciation.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0883-2927 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number (down) THL @ christoph.kuells @ muhr-ebert_speciation_2019 Serial 142
Permanent link to this record
 

 
Author Müller, M.; Alaoui, A.; Külls, C.; Leistert, H.; Meusburger, K.; Stumpp, C.; Weiler, M.; Alewell, C.
Title Tracking water pathways in steep hillslopes by δ18O depth profiles of soil water Type Journal Article
Year 2014 Publication Journal of hydrology Abbreviated Journal
Volume 519 Issue Pages 340-352
Keywords
Abstract
Address
Corporate Author Thesis
Publisher Elsevier Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number (down) THL @ christoph.kuells @ Mueller2014tracking Serial 20
Permanent link to this record