Natural tracers

Nuti, S., Calore, C. Noto, P. 1981. Use of environmental isotopes as natural tracers in a re-injection experiment at Larderello. Proceedings of the 7th Stanford Geothermal Reservoir Engineering Workshop, 85-89. 

Ledesert, B., Joffre, J., Ambles, A., Sardini, P., Genter, A. Meunier, A. 1996. Organic matter in the Soultz HDR granitic thermal exchanger (France) natural tracer of fluid circulations between the basement and its sedimentary cover. Journal of Volcanology and Geothermal Research, 70, 235-253. 

From the above it can be concluded that in many instances the introduction of an artificial radionuclide into the environment provides us with a natural tracer experiment. Indeed, this is the basis for the application of deterministic compartmental models, based on tracer kinetics, to radioecology (Whicker and Schultz, 1982). This approach is largely based on the assumption that radionuclide movements will exhibit first order kinetics although the existence of naturally-occurring tracees (stable isotopes) at relatively high abundance may result in more complex concentration-dependent kinetics. Furthermore, nutrient analogues may exert even more complex effects on processes such as radioion absorption across root plasma membranes this will become evident later in the chapter. 

Corbett, D.R., Dillon, K., Burnett, W., and Chanton, J. (2000) Estimating the groundwater contribution into Florida Bay via natural tracers, 222Rn and CH4. Limnol. Oceanogr. 45, 1546-1557. 

Since the Second World War (WW2), air has become contaminated with trace quantities of derived from the detonation of atomic weapons and can thus be used as a natural tracer. Staddon et al. (2003b) elegantly... 

SklashM. G., Earvolden R. N., andEritz P. (1976) A conceptual model of watershed response to rainfall, developed through the use of oxygen-18 as a natural tracer. Can. J. Earth Sci. 13, 271-283. 

Gast P. W. (1970) Isotopic composition as a natural tracer of lead in the environment. Environ. Sci. Technol. 4, 313—314. 

Kronfeld J. and Rosenthal E. (1981) Uranium isotope as a natural tracer of waters of the Bet-Shean-Harod Valley, Israel. Israel J. Hydrol. 22, 77—88. 

The following sections comprise a brief description of noble-gas isotopes ( He, " He, Ne, and " °Ar), where measured concentrations in ground-waters were found to be in excess of solubility equilibrium with the atmosphere (air-samrated water (ASW)). Such excesses allow the use of these isotopes as natural tracers of groundwater flow (as opposed to those such as °Ne, Ne, Ar, and Ar that exhibit an atmospheric contribution only). 

As mentioned above, direct groundwater age estimation methods may not be well suited for all study areas or with all groundwater tracers. Often, groundwater age estimates are more easily and correctly achieved through incorporation data for natural tracers in analytical and/or numerical transport models. This is particularly true when multiple sources contribute to particular tracers, or when an accurate hydrogeological representation is needed for complex groundwater systems. 

Castro M. C., Goblet P., Ledoux E., Violette S., and de Marsily G. (1998a) Noble gases as natural tracers of water circulation in the Paris Basin 2. Calibration of a ground-water flow using noble gas isotope data. Water Resour. Res. 34, 2467-2484. 

Rutgers van der Loeff M. M., Friedrich M., and Bathmann U. V. (1997) Carbon export during the Spring Bloom at the Antarctic Polar Front, determined with the natural tracer " Th. Deep-Sea Res. II Top. Stud. Oceanogr. 44(1-2), 457-478. 

Stable isotopes studies. Numerous researchers have taken advantage of the difference in carbon isotope fractionation during photosynthesis of plants with C3 and C4 photosynthetic pathways as a natural tracer to study soil carbon dynamics (Balesdent et al., 1987). If a C3 forest is converted to a C4 pasture or C4 agricultural field, the whole soil carbon turnover time (t) can be calculated as... 

Besides the decreasing trend of Hg contents in surface sediments, this hot spot is still active, that is, serving as a source for Hg-rich suspensions participating in a basinwide natural tracer experiment. The 2005 mapping shows a very vivid example of a mercury distribution pattern (geochemical aureole) reflecting the sediment dynamics, including the effects of near-bottom currents. 

N.M. Scully, W.F. Vincent (1996). Hydrogen peroxide A natural tracer of stratification and mixing processes in subarctic lakes. Arch. Hydrobiol. Beih Ergebn. Limnol., 139,1-15. 

Richard P., Shimizu N., and Allegre C. J. (1976) i Nd/i WiNd—a natural tracer an application to oceanic basalt. Earth Planet. Sci. Lett. 31, 269-21S. 

Because the eastern basin water, penetrating into the western trench through the connecting channel, sinks to the bottom layer and forms there a water mass partly retaining the properties of the eastern basin, the relative concentration of calcium in the western basin, generally, decreases downwards, while the sulfate-to-chloride ratio increases. These parameters, therefore, can be thought of as the natural tracers of the eastern basin water intrusions into the bulk of the western basin. 

Berlin C, Bourg ACM (1994) Radon-222 and chloride as natural tracers of the infiltration of river water into an alluvial aquifer in which there is significant river/ground-water mixing. Environ Sci Technol 28 794-798... 

---