Surface sediments of transboundary Lake Peipsi: composition, dynamics and role in matter cycling |
| |
Authors: | Jaan-Mati Punning Anto Raukas Jaanus Terasmaa and Tiit Vaasma |
| |
Institution: | (1) Institute of Ecology at Tallinn University, Uus-Sadama 5, 10120 Tallinn, Estonia |
| |
Abstract: | To describe and analyse the role of sediments in the matter cycling in large shallow transboundary Lake Peipsi (L. Peipsi)
in north-eastern Europe, detailed surface-sediment mapping was conducted. On the basis of grain size the surface sediments
fall into three groups: coarse-grained sediments (prevailingly sands in the lake’s southern part), fine-grained sediments
(mainly silts) and silty sands, both in the central deeper part within the 8-m depth contour. The groups of deposits have
a distinct spatial distribution, determined mainly by the current system in the lake. The main source of bottom sediments
is the erosion of the lake floor and shores, the role of the river input seems to be limited. Fine-grained organic-rich sediments
are very cohesive, playing the main role in the circulation of various inorganic and organic pollutants like nutrients and
xenobiotics. Due to the cohesive character of the sediments their physical and chemical properties are extremely diverse and
if the near-bottom shear stress increases (extreme meteorological events, changes in the water level, etc.), the lake floor
may be subjected to episodic erosion and resuspension, which may cause remobilisation of impurities in muddy sediments and
their return to the food chain. |
| |
Keywords: | Lake sediments Sediment lithology Resuspension Shear stress Lake Peipsi |
本文献已被 SpringerLink 等数据库收录! |
|