Filters: Tags: tritium (X)42 results (26ms)
Summary A detailed local-scale monitoring network was used to assess CFC distribution in an unconfined sand aquifer in southwestern Ontario where the zone of 1–5-year-old groundwater was known with certainty because of prior use of a bromide tracer. Groundwater ⩽5 years old was confined to an aerobic zone at ⩽5 m depth and had CFC concentrations consistent with modern atmospheric mixing ratios at recharge temperatures of 7–11 °C, as was observed in the 3-m thick vadose zone at the site. At depths below 6 m, the groundwater became progressively more reducing, however, with a denitrifying horizon at 6–7 m depth, and a Mn and Fe reducing zone below 7 m depth. In the anaerobic zone, 3H/3He ratios indicated that groundwater-age...
Use of tritium in groundwater to determine fluid mean residence times of Valles caldera hydrothermal fluids, New Mexico, USA
Ground-water quality and flow in a shallow-glaciofluvial aquifer impacted by agricultural contamination
This data release documents three Microsoft Excel tables that contain estimates of tritium in precipitation data for the continental United States. Table 1 contains estimates of tritium in precipitation for precipitation stations located in the continental United States. Measured precipitation data are formatted in regular font while correlated data are italicized. Table 2 contains tritium in precipitation for ninety-six 2-degree latitude by 5-degree longitude quadrangles covering the continental U.S. Latitudes are north of the equator and longitudes are west of the prime meridian. Please see the processing steps below and the main manuscript for additional details on the results presented in this table. Table 3...
Continuous monitoring and discrete water-quality sampling were coupled in a karst aquifer to assess drivers and timescales of water-quality change. Water-quality data included environmental tracers of groundwater age (tritium [3H], tritiogenic helium-3 [3He-trit], sulfur hexafluoride [SF6], carbon-14 [14C], and radiogenic helium-4 [4He-rad]). All water quality data is available from the U.S. Geological Survey NWIS database (U.S. Geological Survey, 2019). Groundwater ages were estimated by calibration of environmental tracers to lumped parameter models of groundwater age for multiple samples collected at six groundwater wells using the program TracerLPM (Jurgens and others, 2012). The final estimates for mean groundwater...
Application of similar media scaling and conditional simulation for modeling water flow and tritium transport at the Las Cruces Trench Site
Identification of Holocene and Pleistocene groundwaters in Hungary using oxygen and hydrogen isotopic ratios
Migration of recharge waters downgradient from the Santa Catalina Mountains into the Tucson basin aquifer, Arizona, USA
From accumulation to discharge: modification of stable isotopes during glacial and post-glacial processes
Temporal environmental isotopic variation within the Falling Creek (Georgia) watershed: Implications for contributions to streamflow
Predicting the Effect of Deep-Rooted Hybrid Poplars on the Groundwater Flow System at a Large-Scale Phytoremediation Site
Categorical classification of groundwater age based on concentrations of tritium (3H) in groundwater can provide useful information for the assessment and understanding of groundwater resources. These data present a three-part groundwater age classification system for the continental United States based on tritium thresholds that vary in space and time: modern (recharged after 1952), if the measured value is larger than an upper threshold; premodern (recharged prior to 1953) if the measured value is smaller than a lower threshold; or mixed if the measured value is between the two thresholds. Inclusion of spatially-varying that vary geographically on the basis of the location of the sample rather than a single threshold...
Homogenization processes affecting isotopic signals ($+18$/O & $+3$/H) in a mountainous hydrological system: the Aosta Valley (Italy)