Isotopic and hydrogeochemical characterization of high-altitude karst aquifers in complex geological settings. The Ordesa and Monte Perdido National Park (Northern Spain) case study

Abstract

The Ordesa and Monte Perdido National Park, located in the Southern Pyrenees, constitutes the highest karst system in Western Europe. No previous studies regarding its geochemical and isotopic groundwater characterization are available in this area. This work presents the results of field and sampling campaigns carried out between July 2007 and September 2013. The groundwater presents high calcium bicarbonate contents due to the occurrence of upper Cretaceous and lower Paleocene--Eocene carbonate materials in the studied area. Other relevant processes include dissolution of anhydrite and/or gypsum and incongruent dissolution of Mg-limestone and dolomite. The water stable isotopes (δ 18 O, δ 2 H) show that the oceanic fronts from the Atlantic Ocean are responsible for the high levels of precipitation. In autumn, winter, and spring, a deuterium excess is found in the recharge water, which could be related to local atmospheric transport of low-altitude snow sublimation vapour and its later condensation on the snow surface at higher altitude, where recharge is mostly produced. The recharge zones are mainly between 2500 m and 3200 m a.s.l.. The tritium content of the water suggests short groundwater transit times. The isotopic composition of dissolved sulphate points to the existence of regional fluxes mixed with local discharge in some of the springs. This work highlights the major role played by the altitude difference between the recharge and discharge zones in controlling the chemistry and the vertical variability of the isotopic composition in high-altitude karst aquifers.

Analysis of home dust for Staphylococcus aureus and staphylococcal enterotoxin genes using quantitative PCR

“…(10 2 –10 3 cells/mg dust) and relatively higher median concentrations for Enterobacteriaceae (10 3 cells/cm 2 dust) and Bifidobacteriacae spp. (10 4 cells/mg dust) (Kaarakainen et al, 2009; Rinatala and Nevalainen, 2006; Scherer et al, 2014; Valknonen et al, 2015). …”

“…In prior studies, microbial DNA-based methods using quantitative PCR (qPCR) methods have demonstrated good reliability and applicability to large cohorts for assessment of microbial exposures in home dust samples (Fujimura et al, 2012; Kaarakainen et al, 2009; Rintala et al., 2008; Scherer et al, 2014). DNA-based methods may provide a less biased estimate of microbial exposures than culture-based methods, which require organism viability and cultivability (Kaarakainen et al, 2009).…”

Understanding snow hydrological processes through the lens of stable water isotopes

“…A number of studies around the world have reported on the effect of isotopic lapse rates of precipitation in streamwater (Jeelani, Saravana Kumar, & Kumar, ; Wen et al, ), groundwater (Lambán et al, ; O'Driscoll, DeWalle, McGuire, & Gburek, ), and soil water (O'Driscoll et al, ). However, this effect can be masked by other fractionating processes as well as elevation‐dependent recharge processes.…”

Local vs. Regional Groundwater Flow Delineation from Stable Isotopes at Western North America Springs

“…A detailed isotopic analysis of groundwater discharging from Ash Meadows, Nevada, confirmed this interpretation, claiming flow to have come from the opposite direction, and proposed that structurally complex basins are not as interconnected as previously thought (Bushman et al 2010). Similar studies from the Ordesa Na Monte Perdido National Park in Northern Spain determined control of elevation of precipitation on the isotopic composition of recharge and discharge zones (Lamban et al 2015).…”