Tritium 3he dating of shallow groundwater pittsburgh online dating services
He serves as Co-Chair of Barnard's Department of Environmental Science. Professor Stute holds a concurrent position as Adjunct Senior Research Scientist at the Lamont-Doherty Earth Observatory and is a member og the faculty of Columbia's Department of Earth and Environmental Science. Lumped parameter models for the interpretation of environmental tracer data. Influence of droughts on remote villages in the karst region of Guizhou Province, China: Causes and control[J].and is 300 times greater than can be supported by the in situ decay of U and Th series nuclides (i.e., the 'steady state' approximation). PY - 1996/6Y1 - 1996/6N2 - Radiogenic helium 4(4He(rad)) has been used in numerous studies as a tracer of groundwater age in the range of 103-108 years.According to the atmospheric input curve of 85Kr, the 85Kr age of groundwater is determined. Journal of Environ-mental Radioactivity, 127: 111-118 . 268, Zhonghua North Street, Shijiazhuang City, Hebei Province, 050061, P. We conducted 85Kr analysis in three wells in Zhengding County on the plains in front of the Taihang Mountains, and made a comparison with tritium (3H) method.
against diffusive loss at the water table and on the amount of dispersive mixing that occurs within the saturated zone of shallow unconfined aquifers. Recharge rates have been computed using the 3H/3He age gradients and vary from 62 cm yr-1 beneath the Borden landfill to 14 cm yr-1 north of the landfill.
The combined laboratory and field release data yield 4He diffusion coefficients that exhibit an Arrhenius temperature dependence that is similar to 4He diffusion in quartz reported by other researchers.
The 4He(rad) release rate at the Ontario site is extraordinarily similar to sites in Tennessee, Nebraska, and Germany in spite of major hydrogeologic differences.
TY - JOURT1 - Source of radiogenic helium 4 in shallow aquifers T2 - Water Resources Research AU - Solomon, D. Metamorphic rocks of the Canadian Shield (1 Ga) that contain large quantities of 4He are the protolith of this unconsolidated aquifer and observed 4He(rad) values increase linearly with distance along a flow path and with increasing groundwater age.
A solute transport model suggests that the aquifer solids are the source of 4He(rad) as vertical fluid velocities are too great to allow upward diffusion of 4He(rad) from the underlying shield rocks.
H., Gunnlaugsson, E., Holmfridur S., Sigfusson, B., Broecker, W.