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H, half-life of 12.43 years (Unterweger and others, 1980)) has provided an excellent tracer of young waters.
A central aspect in karst hydrology is the time required for the rainwater to reach the point of discharge in a cave, e.g. One promising approach in determining this residence time is drip-water dating by tritium (H).
In contrast to traditional tritium dating, we do not refer directly to tritium concentrations in precipitation as input function, but to an infiltration-weighted annual mean of the rainwater values.
H), and other chemical and isotopic substances in ground water, can be used to trace the flow of young water (water recharged within the past 50 years) and to determine the time elapsed since recharge.
Information about the age of ground water can be used to define recharge rates, refine hydrologic models of ground-water systems, predict contamination potential, and estimate the time needed to flush contaminants from ground-water systems.
CFCs also can be used to trace seepage from rivers into ground-water systems, provide diagnostic tools for detection and early warning of leakage from landfills and septic tanks, and to assess susceptibility of water-supply wells to contamination from near-surface sources.
During the past 50 years, human activities have released an array of chemical and isotopic substances to the atmosphere.
Shallow ground-water systems are commonly used for drinking water sources and they make up a large part of the baseflow in rivers and lakes.
However, shallow ground-water supplies are generally young (recently recharged) and, because there has been a wide variety of man-made pollutants produced in the 20th century, are more susceptible to contamination than deeper ground water.
So, it was quite a surprise when construction scientist, Moira Wilson, came up with a really simple method of dating ceramics...
Moira - I think the problem is, that most people think that carbon-14 dating can be used to date anything. It can only be used to date things that have been living like, you know - plant material, bone, or whatever that's been exchanging carbon with the atmosphere throughout its lifetime. That's the first thing and you certainly can't carbon date pottery.
Now, our method is self-calibrating and doesn't require any material from around the excavated site.