Isotopic composition of precipitation and river water: measurement of δ[superscript 2]H, δ[superscript 17]O, δ[superscript 18]O, and [superscript 3]H in southeastern New Brunswick

Abstract

The isotopic composition of precipitation and surface water in southeastern New Brunswick was studied over twelve months (2016-2017) to complement a prior regional groundwater quality study. Monthly samples for three precipitation sites and six surface water sites were collected to assess seasonal/temporal variability, plus seven one-time samples to assess spatial variability. The Palmex Ltd. RS1 rain sampler (equipped with heating coils in winter) was used. Samples were analyzed for δ[superscript 18]O, δ[superscript 2]H, δ[superscript 17]O (all samples) and tritium (selected samples), then compared to climatic/hydrometric data and existing precipitation and surface water data. The Local Meteoric Water Line (LMWL) developed was similar to an established LMWL for Truro, NS (1975–1983), but different than Harcourt, NB (1997–2010). Tritium results for precipitation were approximately 10% of those circa 1980 in Truro, NS. Results will be submitted to the Global Network of Isotopes in Precipitation/Rivers (GNIP/GNIR). Performance of the precipitation collector and heating system was evaluated.