HYDROPHYSICAL PROCESSES AND DISTRIBUTION OF DISSOLVED SILICON IN LAKE BAIKAL

Abstract

Measurements in Baikal taken in 1993-97 have revealed some regularities in regime and turnover of silicon in different parts of the lake. Vertical distribution of silicon is controlled by advection of either low-Si (limnic) or high-Si (river) surface water to pelagic depths. Considerable spatial variations in concentration and total amount of silicon are due to vertical circulation of water near the basin slopes and in the open lake. Turnover of silicon has been estimated separately for different parts of Lake Baikal, with regard for local inflow from outside and transport by water exchange within the lake. It was inferred that the annual turnover of silicon (as well as its production by diatoms) and the rate of its accumulation in bottom sediments decrease from the Southern and Central basins toward the Northern basin with a colder climate.