CLIMATE AND LONG-TERM SILICA DYNAMICS IN THE WATER OF LAKE BAIKAL

Abstract

Experiments show a considerable silica decrease in the water of Baikal through 1995-2001 in the conditions of anomalous local warming in the lake region and growing phytoplankton production. Annual silica loss in those years was over 4 times the typical loss in normal conditions, and ~30 years of river input is required to make up for the total deficit. Silica variations were modeled as fluxes from bottom to surface waters for the three subbasins of the lake. Long-term variations of silica contents in the Baikal water are apparently controlled by climate. Secular warming peaks are marked by 4-6 times greater consumption of silica by diatoms and its correspondingly faster accumulation in bottom sediments of Baikal.