Jaromy R. Green

Earth paleoenvironments : records preserved in mid- and low-latitude glaciers

Part I: Introduction And Methods 1. High-Altitude, Mid and Low-Latitude Ice Core Records: Implications for our Future by L.G. Thompson 2. Methods of Mid- and Low-Latitude Glacial Record Collection, Analysis, and Interpretation by J.R. Green, L.D. Cecil and S.K. Frape Part II: The Climate And Environmental Change Record Over The Last 200 Years 3. The Influence of Post-Depositional Effects on Ice Core Studies: Examples from the Alps, Andes, and Altai by U. Schotterer, W. Stichler and P. Ginot 4. Event to Decadal-Scale Glaciochemical Variability on the Inilchek Glacier, Central Tien Shan by K. Kreutz, C.P. Wake, V.B. Aizen, L.D. Cecil, J.R. Green and H.A. Synal 5. Climatic Interpretation of the Gradient in Glaciochemical Signals Across the Crest of the Himalaya by C.P. Wake, P.A. Mayewski and S. Kang 6. Reconstruction of European Air Pollution from Alpine Ice Cores by M. Schwikowski 7. Glacier Research in Mainland Scandinavia by W.B. Whalley Part III: The Climate And Environmental Change Record Over The Last 200 - 500 Years 8. Four Centuries of Climatic Variation Across the Tibetan Plateau from Ice-Core Accumulation and d18O Records by M.E. Davis and L.G. Thompson 9. Climatic Changes over the Last 400 Years Recorded in Ice Collected from the Guliya Ice Cap, Tibetan Plateau by Y. Tandong and Y. Meixue 10. Evidence of Abrupt Climate Change and the Development of an Historic Mercury Deposition Record Using Chronological Refinement of Ice Cores at Upper Fremont Glacier by P.F. Schuster, D.L. Naftz, L.D. Cecil and J.R. Green 11. Variations between d18O in Recently Deposited Snow and On-Site Air Temperature, Upper Fremont Glacier, Wyoming by Naftz, D.D. Susong, L.D. Cecil and P.L. Schuster

Use of chlorine-36 to determine regional-scale aquifer dispersivity, eastern Snake River Plain aquifer, Idaho/USA

Abstract Chlorine-36 ( 36 Cl) derived from processed nuclear waste that was disposed at the US Department of Energy’s Idaho National Engineering and Environmental Laboratory (INEEL) through a deep injection well in 1958, was detected 24–28 yr later in groundwater monitoring wells approximately 26 km downgradient from the source. Groundwater samples covering the period 1966–1995 were selected from the US Geological Survey’s archived-sample library at the INEEL and analyzed for 36 Cl by accelerator mass spectrometry (AMS). The smaller 36 Cl peak concentrations in water from the far-field monitoring wells relative to the input suggest that aquifer dispersivity may be large. However, the sharpness of the 1958 disposal peak of 36 Cl is matched by the measured 36 Cl concentrations in water from these wells. This implies that a small aquifer dispersivity may be attributed to preferential groundwater flowpaths. Assuming that tracer arrival times at monitoring wells are controlled by preferential flow, a 1-D system-response model was used to estimate dispersivity by comparing the shape of predicted 36 Cl-concentration curves to the shape of 36 Cl-concentration curves measured in water from these observation wells. The comparisons suggest that a 1-D dispersivity of 5 m provides the best fit to the tracer data. Previous work using a 2-D equivalent porous-media model concluded that longitudinal dispersivity (equivalent to 1-D dispersivity in our model) was 90 m (Ackerman, US). A 90 m dispersivity value eliminates the 1958 disposal peak in our model output curves. The implications of the arrival of 36 Cl at downgradient monitoring wells are important for three reasons: (1) the arrival times and associated 36 Cl concentrations provide quantitative constraints on residence times, velocities, and dispersivities in the aquifer; (2) they help to refine our working hypotheses of groundwater flow in this aquifer and (3) they may suggest a means of estimating the distribution of preferential flowpaths in the aquifer.

Evidence of Abrupt Climate Change and the Development of an Historic Mercury Deposition Record Using Chronological Refinement of Ice Cores at Upper Fremont Glacier

Paleoclimatic and paleoenvironmental ice-core records are not common from mid-latitude locations in the contiguous U.S.A. Although excellent paleo-records exist for the high latitudes (Hammer, 1980; Lyons et al., 1990, Dansgaard et al., 1993, Taylor et al., 1993a; Clausen et al., 1995, Alley et al., 1997, Johnsen et al., 1997, Jouzel et al., 1997, Mayewski et al., 1997, Taylor et al., 1997, White, J.W.C, et al., 1997, Zielinski et al., 1997), icecore records from polar regions may be considered proxy indicators of climatic and environmental change in the mid latitudes. Unlike polar ice cores which are more likely to preserve visual, chemical and isotopic stratigraphy with sub-annual resolution, visual stratigraphy and sub annual isotopic resolution are generally not apparent in mid-latitude ice cores. In addition, meltwater percolation can influence chemical and isotopic stratigraphy of alpine glaciers from mid-latitude ice cores by “damping” the environmental signal (Wagenbach, 1989). Despite these problems, Naftz (1993), Naftz et al., (1994), Naftz et al. (1996) and Cecil and Vogt (1997), through chemical lines of evidence, indicated that the Upper Fremont Glacier (UFG) in the Wind River Range, Wyoming, U.S.A., (43° 07’ 37” N,

Methods of Mid- and Low-Latitude Glacial Record Collection, Analysis, and Interpretation

Because the majority of the word’s population live at mid- and low-latitudes, it is vital to understand how the environment is changing, on local, regional, and global scales. Mid- and low-latitude glaciers provide a unique opportunity to look at how the environment has changed in the past, how it is changing today, and to project possible changes in the future. The study of mid- and low-latitude glacial ice is not simple, but the process of collecting, analyzing, and interpreting such ice has been, and continues to be, refined. New techniques, lower analytical detection levels, and expanded studies have provided a solid foundation on which to base the wealth of data recorded in mid- and low-latitude glaciers, which in turn facilitates application of the information obtained to societal problems and resource evaluation.

Chlorine-36 in Water, Snow, and Mid-Latitude Glacial Ice of North America: Meteoric and Weapons-Tests Production in the Vicinity of the Idaho National Engineering and Environmental Laboratory, Idaho

Measurements of chlorine-36 (36Cl) were made for 64 water, snow, and glacial-ice and -runoff samples to determine the meteoric and weapons-tests-produced concentrations and fluxes of this radionuclide at mid-latitudes in North America. The results will facilitate the use of 36Cl as a hydrogeologic tracer at the Idaho National Engineering and Environmental Laboratory (INEEL). This information was used to estimate meteoric and weapons-tests contributions of this nuclide to environmental inventories at and near the INEEL. The data presented in this report suggest a meteoric source 36Cl for environmental samples collected in southeastern Idaho and western Wyoming if the concentration is less than 1 x 10 7 atoms/L. Additionally, concentrations in water, snow, or glacial ice between 1 x 10 7 and 1 x 10 8 atoms/L may be indicative of a weapons-tests component from peak 36Cl production in the late 1950s. Chlorine-36 concentrations between 1 x 10 8 and 1 x 10 9 atoms/L may be representative of re-suspension of weapons-tests fallout airborne disposal of 36Cl from the INTEC, or evapotranspiration. It was concluded from the water, snow, and glacial data presented here that concentrations of 36Cl measured in environmental samples at the INEEL larger than 1 x 10 9 atoms/L can be attributed to waste-disposal practices.