Baltic groundwater isotope-geochemistry database

The database compiles data of the isotopic, chemical and noble gas composition of groundwater in Estonia, Latvia and Lithuania based on the work done by Division of Isotope Geology (and its predecessors) at the Department of Geology, Tallinn University of Technology. The published database is an updated and verified version of the in-house database for groundwater data held by the division. It contains data of 1079 groundwater samples collected during the period 1974–2017. The division has been responsible for either collecting the samples, sample analysis or both. Database contains data of the chemical (major ions, minor ions, trace elements, alkalinity), isotopic (stable isotope ratios of δ2H-water, δ18O-water, δ13C-DIC, CH4, CO2, δ2H-CH4, δ34S-SO4, δ18O-SO4; activities of Ra-226, Ra-228; C-14 and tritium) and dissolved gas (noble gas concentrations of He, Ne, Ar, Kr, Xe; He-3/He-4 ratios; Kr-81 and Kr-85 ages; CO2 and CH4 concentrations) composition of groundwater. It also contains details on the location and construction of the sampled wells as well as on the location for sampled springs. Information about the laboratories, where analyses have been made and details about analytical methods that have been used has been added. The database is complemented by references to the previously published results. Financial support for preparing the database for publishing has been provided by Estonian Research Council Project IUT19-22 “Groundwater flow history, global paleoclimate signals and anthropogenic influence in the Baltic Artesian Basin: a synthesis of numerical models and hydrogeochemical data” (2014-2019, R.V.). Data collection, analysis and publication during the years has been supported by several grants by the Estonian Science Foundation, Estonian Research Council as well as various other local and international financial sources. Detailed information about the projects related to the published data can be found in the full version of the abstract in the accompanying zip-file and in the acknowledgement sections of the published papers referred to in the accompanying table of references. Most of the data in the database will be made publicly available on the webpage of the Geoscience Collections of Estonia (https://geocollections.info) developed and maintained by the Department of Geology, Tallinn University of Technology. Some of the data which is part of manuscripts in preparation at the time of the database publication will be made public after the publication of those manuscripts. The authors would like to thank Hannes Martma and Ülle Männik (laboratory of mass-spectrometry), Heivi Rajamäe (radiocarbon laboratory) and Velli Just (hydrochemical analysis) for their work on sample preparation and analysis in the respective laboratories. Also, we would like to thank all partners and co-authors, who have co-operated with the department on sample collection, sample analyses and publications through the years. All the previously published results in the database should be referred to using the reference of the original publication. Previously unpublished data in the database should be cited as: Vaikmäe, R., Martma, T., Ivask, J., Kaup, E., Raidla, V., Rajamäe, R., Vallner, L., Mokrik, R., Samalavičius, V., Kalvāns, A., Babre, A., Marandi, A., Hints, O., Pärn, J. 2020. Baltic groundwater isotope-geochemistry database. Department of Geology, Tallinn University of Technology. https://doi.org/10.15152/GEO.488.