Journal of Hydrology
Journal of Hydrology
5 years ago

Geospatial drivers of the groundwater δ18O isoscape in a temperate maritime climate (Republic of Ireland)

In recent years, the concept of “isoscapes” has been used to describe spatiotemporal stable isotope distributions within natural environments including groundwater systems at multiple scales. This study presents an updated groundwater δ18O isoscape for the Republic of Ireland and describes the climatic and geological drivers influencing 18O composition. In all, 142 geographically and geologically representative groundwater installations were sampled and analysed, in addition to 35 samples from six nested boreholes. Geospatially, Irish groundwater exhibits high δ18O values in southern and western coastal regions, becoming progressively depleted inland before reaching lowest measured values along the eastern coast, equating to a national groundwater δ18O profile range of approximately 3‰. Groundwater δ18O composition is primarily driven by location with respect to orographically influenced rainfall deposition and annual precipitation volume, with a bias towards winter recharge. Results also demonstrate that local/regional (hydro)geological setting exerts a secondary influence on δ18O composition via infiltration and recharge mechanisms. “Flashy” groundwater systems (e.g. karst limestones) are more likely to exhibit seasonal groundwater δ18O patterns, whereas low productivity systems with high residence times (e.g. granites), tend to display a dampened composition to groundwater recharge and exhibit more temporally constant δ18O values. The derived δ18O isoscape enhances current understanding of what is a geologically distinct groundwater setting, whilst also potentially serving as a δ18O “sentinel” for continental Europe, with respect to both groundwater and precipitation, due to Ireland’s geographic location.

Publisher URL: www.sciencedirect.com/science

DOI: S0022169417306170

You might also like
Discover & Discuss Important Research

Keeping up-to-date with research can feel impossible, with papers being published faster than you'll ever be able to read them. That's where Researcher comes in: we're simplifying discovery and making important discussions happen. With over 19,000 sources, including peer-reviewed journals, preprints, blogs, universities, podcasts and Live events across 10 research areas, you'll never miss what's important to you. It's like social media, but better. Oh, and we should mention - it's free.

  • Download from Google Play
  • Download from App Store
  • Download from AppInChina

Researcher displays publicly available abstracts and doesn’t host any full article content. If the content is open access, we will direct clicks from the abstracts to the publisher website and display the PDF copy on our platform. Clicks to view the full text will be directed to the publisher website, where only users with subscriptions or access through their institution are able to view the full article.