10.1594/PANGAEA.992434Böttcher, Michael ErnstMichael ErnstBöttcher0000-0002-8877-0303Leibniz Institute for Baltic Sea Research, WarnemündeUniversity of GreifswaldEhlert von Ahn, Cátia MileneCátia MileneEhlert von Ahn0000-0001-7524-5908Leibniz Institute for Baltic Sea Research, WarnemündeDellwig, OlafOlafDellwig0000-0002-0028-8812Leibniz Institute for Baltic Sea Research, WarnemündeStruck, UlrichUlrichStruckFreie Universität BerlinGehre, MatthiasMatthiasGehreHelmholtz Centre for Environmental Research - UFZEscher, PeterPeterEscherLeibniz Institute for Baltic Sea Research, WarnemündeVogler, SusannSusannVoglerLeibniz Institute for Baltic Sea Research, WarnemündeSzymczycha, BeataBeataSzymczycha0000-0002-5815-215XInstitute of Oceanology Polish Academy of SciencesKotwicki, LechLechKotwicki0000-0001-5876-5696Institute of Oceanology Polish Academy of SciencesPANGAEA2026coastal sandHel Islandporewater geochemistryPuck BaySeasonalitysouthern Baltic Seastable isotope compositionSubmarine groundwater dischargeEvent labelLATITUDELONGITUDEDATE/TIMETypeDEPTH, sediment/rockSalinitypHHydrogen sulfideCalciumSodiumPotassiumMagnesiumSulfurSiliconPhosphorusIronManganeseBariumδ18O, porewaterδ Deuterium, porewaterδ13C, dissolved inorganic carbonAlkalinity, totalδ13C, methane, porewaterδ Deuterium, methaneAmmoniumNamePorewater lanceCTDIon selective electrodeSpectrophotometry using methylene blue method according to Cline (1969)Inductively coupled plasma–optical emission spectrometer (ICP-OES), Thermo Fisher ScientificScientific, iCAP 6300Cavity ring-down spectroscopy (CRDS), isotopic water analyzer, Picarro Inc., L1102-iIsotope ratio mass spectrometer (IRMS), MAT; coupled with Gas benchPotentiometric titrationGas chromatography - isotope ratio mass spectrometry (GC-IRMS)QuAAtro AutoAnalyzer2009-09-02T00:00:00/2010-10-05T00:00:00Dataset10.1016/j.oceano.2024.01.0012037 data pointstext/tab-separated-valuesCreative Commons Attribution 4.0 InternationalPore waters were retrived from coastal sands of the southern coastline off Hel Island, Puck Bay, southern Baltic Sea. Multiport-porewater lances equipped with syringes were used to obtained vertical profiles in areas impacted by fresh submarine groundwater discharge and less impacted 'reference sites'. Samples were taken during 11 campaigns between September 2009 and October 2010. Pore waters were analyzed on-site for salinity and pH, and for major and trace elements, water isotopes (H,O) and the C isotope composition of dissolved inorganc carbon in the laboratory (via ICP-OES and gas mass spectrometry). Selected methane samples were analyzed via GCirmMS for the C and H isotope composition. It was the aim to investigate the fluxes and fresh water composition of submarine groundwater discharge and the seasonal dynamics.18.854.604999999999826Puck Bay, Baltic Sea, PolandFederal Ministry of Education and Researchhttps://doi.org/10.13039/50110000234703F0485AAssessment and Modelling Baltic Ecosystem Response (AMBER) BONUSGerman Academic Exchange Servicehttps://doi.org/10.13039/50110000165557381412DAAD_Phd scholarship