Oxygen isotopic and soluble ionic composition of a shallow firn core, Inilchek glacier, central Tien Shan
Oxygen isotopic and soluble ionic measurements made on snow-pit (2 m depth) and firn-core (12.4 m depth) samples recovered from the accumulation zone (5100 m) of Inilchek glacier (43°:N, 79°E) provide information on recent (1992-98) climatic and environmental conditions in the central Tien Shan region of central Asia. The combined 14.4 m snow-pit/firn-core profile lies within the firn zone, and contains only one observed melt feature (10 m temperature = -12°C). Although some post-depositional attenuation of the sub-seasonal 18O record is possible, annual cycles are apparent throughout the isotope profile. We therefore use the preserved 18O record to establish a depth/age scale for the core. Mean 18O values for the entire core and for summer periods are consistent with 18O/tem- perature observations, and suggest the 18O record provides a means to reconstruct past changes in summer surface temperature at the site. Major-ion (Na+, K+, Mg2+, Ca 2+, NH4+, Cl-, NO3=, SO42-)data from the core demonstrate the dominant influence of dust deposition on the soluble chemistry at the site, and indicate significant interannual variabil- ity in atmospheric-dust loading during the1990s. Anthropogenic impacts on NH4 +concen- trations are observed at the site, and suggest a summer increase in atmospheric NH4 +that may be related to regional agricultural (nitrogen-rich fertilizer use) activities.
Journal of Glaciology
International Glaciological Society
Digital Object Identifier (DOI)
Kreutz, KJ, Aizen, VB, Cecil, LD, and Wake, CP, 2001, Oxygen Isotopic and Soluble Ionic Composition of a Shallow Firn Core, Inilchek Glacier, Central Tien Shan: Journal of Glaciology, v. 47, p. 548-554. Available on publisher's site at: http://www.ingentaconnect.com/content/igsoc/jog/2001/00000047/00000159/art00003
© Copyright 2001 by the International Glaciological Society