Variation of dust concentration in an ice core at Belukha Glacier, Russian Altai Mountains

摘要

In this study, we evaluated the variation of concentration, size distribution and deposition rate of dust in an ice core at Belukha Glacier, Russian Altai Mountains by the microparticle analysis with a laser-light scattering method. The concentration of microparticles is lower than those of snow in glaciers in Tibetan Plateau and greater than those in ice cores in Antarctica. The mean size distributions at this glacier show a logarithmic decrease with increase grain size for number-size one and a noticeable bimodal for mass-size one, for microparticle diameters ranging from 0.52 to 16 μm, respectively. These distributions are similar to those of snow in some glaciers in Tibetan Plateau, although the mass concentrations of micorparticles in these glaciers are 50 to 200 times greater than that of Beluhka Glacier. Net annual dust depositions at Belukha Glacier from 2000 to 2003 are 12 to 15 μg cm~(-2)yr~(-1), which are the lowest deposition rates of dust comparing to glaciers in Tibetan Plateau, although net annual snow accumulations at this site are approximately equal to the glaciers in Tibetan Plateau except ones in Karakoram and Pamirs.