HR: 1340h
AN: GC23A-0989    [Abstracts]
TI: A 100 yr Ice Core Record of Anthropogenic Activity, Volcanic Eruptions, and Biomass Burning From the Siberian Altai
AU: * Joswiak, D R
EM: djoswiak@vandals.uidaho.edu
AF: Univ of Idaho, Dept of Geography McClure Hall 203, Moscow, ID 83844, United States
AU: Aizen, E
EM: eaizen@uidaho.edu
AF: Univ of Idaho, Dept of Geography McClure Hall 203, Moscow, ID 83844, United States
AU: Aizen, V
AF: Univ of Idaho, Dept of Geography McClure Hall 203, Moscow, ID 83844, United States
AU: Takeuchi, N
AF: Chiba Univ Graduate School of Science, 1-33, Yayoi-cho, Inage-ku, Chiba, 263-8522, Japan
AU: Sneed, S
AF: Univ of Maine, Climate Change Institute Sawyer Env Research Center, Orono, ME 04469, United States
AB: The 50m upper part from 170m of total deep ice core was retrieved from the Belukha snow-ice plateau (49°48’N, 86°32’E, 4110m.a.s.l.) in the summer of 2003 representing the time series since the beginning of the 20^th Century. Data on high-resolution physical stratigraphy and density, as well as geochemical data including major ions, stable (δ¹⁸O) and radiogenic (δ³H) isotopes were developed for ice-core dating, climatic and environmental analysis. A clear tritium isotope ratio peak associated with the global maximum nuclear testing of the early 1960’s, and a soluble major ion peak coincident with the eruption of Mt. Katmai in 1912 reveals a linear depth-age scale for the upper 50m and indicates an average accumulation rate of 376m.w.e. Major soluble ions sulfate and nitrate showed the greatest increase subsequent to the 1950’s, and provides evidence for direct effects associated with increased atmospheric aerosol loading from industrialized activity in central Asia. Extremely low sulfate and nitrate concentrations (<3.0μEq/L average) before the 1950’s approximate atmospheric background levels. Sulfate concentrations decrease rapidly during the time period associated with the early 1990’s, providing an example of the effects of short-run deindustrialization subsequent to the dissolution of the Soviet Union. Ammonium concentrations reveal an association with documented periods of extended boreal forest fires during the 1960’s and 1970’s. Elevated calcium concentrations during the 1950’s and 1960’s correspond to the reported period of maximum dust activity in China since 1950.
DE: 0335 Ion chemistry of the atmosphere (2419, 2427)
DE: 0724 Ice cores (4932)
DE: 0776 Glaciology (1621, 1827, 1863)
SC: Global Environmental Change [GC]
MN: 2007 Fall Meeting