 |
2007 Ground Water Summit |
Tuesday, May 1, 2007 : 10:00 a.m.
Controls on the Relationship Between Recharge Elevation and Ground Water Oxygen and Hydrogen Isotopic Composition on the Pajarito Plateau of Northern New Mexico
The empirical relationships developed by Vuataz and Goff are only calibrated to a lower elevation of 2260 m, whereas it has been speculated that recharge may occur at lower elevation on the Plateau itself. To determine the validity of extrapolating the recharge elevation – isotope relationships to lower elevation it is necessary to understand the isotopic controls that lead to those relationships. These could include, but are not limited to, 1) the classic temperature dependent altitude effect, 2) the pseudo-altitude effect, 3) the relative importance of different precipitation sources with different isotopic signatures over an elevation gradient, and 4) variation in the location and timing of infiltration at different elevations.
A model will be presented which examines the relative importance of these various isotopic effects in yielding the observed isotopic relationships. This model will be constrained to recent GIS-based models of infiltration for the eastern edge of the Jemez Mountains and the Pajarito Plateau and to measurements of the isotopic composition of local precipitation. This will allow for a determination of the likely nature of recharge elevation—isotope relationships extended to the Pajarito Plateau itself.
Jeffrey M. Heikoop, Ph.D., Los Alamos National Laboratory Dr. Heikoop is an isotope geochemist with research interests including 1) the use of nitrogen, carbon, chlorine, oxygen, deuterium and sulfur isotopes as geochemical tracers of pollution; 2) contaminant dynamics in complex surface and subsurface environments; and 3) reconstructing paleoclimate records from the lake sediments, bogs, corals and tree rings. He has a Ph.D. degree in geology from McMaster University and is currently a Project Leader in the LANL Water Stewardship Program.
Patrick Longmire, Ph.D., Los Alamos National Laboratory Dr. Patrick Longmire is an aqueous geochemist at Los Alamos National Laboratory specializing in the fate and transport of radionuclides and inorganic contaminants in ground-water systems. Patrick has been investigating the use of permeable reactive barrier technology to remediate ground water contaminated with perchlorate, nitrate, metals, and radionuclides. Dr. Longmire has 30 years of experience in the field of aqueous environmental geochemistry. Patrick has been teaching short courses on ground water geochemistry for NGWA since 1986.
Michael Dale, M.Sc., New Mexico Environment Department, DOE Oversight Bureau Michael Dale is a hydrogeologist with the New Mexico Environment Department. Michael conducts hydrogeochemical investigations including measuring naturally-occurring perchlorate and delineating ground-water flow paths using isotopic and chemical tracers. Michael has 13 years experience in the fields of hydrochemistry and hydrogeology.
Kim P. Granzow, New Mexico Environment Department, DOE Oversight Bureau Kim Granzow is an environmental scientist/geologist with the New Mexico Environment Department. Kim specializes in environmental monitoring for naturally occurring and anthropogenic contaminants such as perchlorate and plutonium, and utilizes Geographic Information Systems (GIS) in hydro-contaminant investigations. Kim has 11 years of experience in the field of geology and five years experience in GIS.