Abstract
The Pretoria Salt Pan, South Africa, a small (0.076 km2), shallow (Zmax = 2.85 m), hypersaline, maar lake, lies within a clearly-defined crater and is fed by a perennial, slightly saline (3 g l-1) artesian spring. The lake has two distinct solar-heated peaks in its temperature profile, each of these peaks located in a highly turbid (> 80 JTU) layer below a steep chemocline. The upper thermal peak, located at a depth of 10 cm, was transient, with a distinct diel pattern of diurnal heating and nocturnal cooling. The lower thermal peak, located below a steep chemocline and centred at approximately 60 cm, was stable and showed a seasonal pattern of winter heating (maximum: 38.5 °C) and summer cooling (minimum: 27.4 °C). The unusual bathymetry of the lake, combined with the sheltering effect of the crater rim and steep salinity gradient between the surface (30–80 g l-1) and bottom water (280–310 g l-1) prevented windmixing of surface waters beyond a depth of approximately 50 cm. During a 28 month study all water deeper than 55 cm remained anaerobic, and the lake appeared to be meromictic.
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© 1988 Dr W. Junk Publishers, Dordrecht
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Ashton, P.J., Schoeman, F.R. (1988). Thermal stratification and the stability of meromixis in the Pretoria Salt Pan, South Africa. In: Melack, J.M. (eds) Saline Lakes. Developments in Hydrobiology, vol 44. Springer, Dordrecht. https://doi.org/10.1007/978-94-009-3095-7_20
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DOI: https://doi.org/10.1007/978-94-009-3095-7_20
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