Thermal summer characteristics of lakes and ponds on Deception Island,Antarctica |
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Authors: | Edmundo C Drago |
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Institution: | (1) Instituto Nacional de Limnología (CONICET), J. Macia 1933, 3016 Santo Tomé, Santa Fe, Argentina |
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Abstract: | During January and February 1981, water temperature measurements were made in lakes and ponds of Deception Island, Antarctica.
The depth of these waterbodies varies between 0.88 m and 36 m, with maximum surface areas of over 290 000 m2. Some ponds freeze completely during winter, and the lakes are covered by ice for 9–10 months of each year. The maximum ice
thickness measured in early summer (December), dit not exceed 0.5 m.
Solar radiation and geothermal heating largely determine the thermal structure of these aquatic environments. The water temperature
of tributary meltwater streams did not exceed 3 °C, but the littoral waters reached 9 °C. The bottom water temperatures of
meromictic lakes 5 (Irízar) and 9, are 12.3 °C and 19.9 °C respectively. These deep waters are heated from geothermal sources
and it is possible that some ponds may be also influenced by their proximity to hot soils. With the exception of the meromictic
lakes, the aquatic environments studied here did not show a vertical stratification of temperature.
It is not possible to establish a general thermal classification for the waterbodies of Deception Island. The interaction
of the lacustrine morphology, solar radiation and vulcanism produce contrasting thermal features. Taking into account only
the upper layers of meromictic lakes (mixolimnion), and emphasizing the fact of that some ponds freeze completely during winter,
the waterbodies of Deception Island would be classified as ‘pleomictics’ (Paschaslki, 1964).
This work was supported by an agreement between the Instituto Antártico Argentino and the Instituto Nacional de Limnología
(Programa Limnoantar).
This work was supported by an agreement between the Instituto Antártico Argentino and the Instituto Nacional de Limnología
(Programa Limnoantar). |
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Keywords: | Antarctica Deception Island lakes ponds water temperature geothermal heating thermal classification |
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