Hydrogen isotope study of large-scale meteoric water transport in Northern California and Nevada
1986; Elsevier BV; Volume: 85; Issue: 1-2 Linguagem: Inglês
10.1016/0022-1694(86)90084-3
ISSN1879-2707
AutoresNeil L. Ingraham, Bruce E. Taylor,
Tópico(s)Geophysics and Gravity Measurements
ResumoThe depletion of deuterium in surface- and shallow groundwaters along a traverse through Northern California and Nevada is used to model the local hydrologic balance as controlled by the eastward flux of meteoric water in a way not possible by conventional methods. When plotted against distance from the Pacific Ocean, our data indicate three hydrologic provinces which differ in their relative degree of openness. Isotopic variations of groundwater in the first province are governed by Rayleigh distillation from the eastward-moving storm clouds. Some 40% of the storm water vapor precipitates out before reaching the California coast, and another 16% in the first 55 km across the continent. The isotopic depletion in the second hydrologic province is linear with distance, and this suggests extensive recycling of terrestrial water. The third province constitutes the Great Basin, characterized by the lack of significant hydrogen isotope variation of groundwater, is thought to be an isotopically closed system. The quantity of water crossing the coast calculated from a model that incorporates the Rayleigh distillation equation is approximately equal to the quantity of precipitation along the Northern California part of the transect studied. This illustrates the importance of evapotranspiration in the terrestrial water budget, as well as the dependency of inland areas on the eastward flux of recycled terrestrial water.
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