ISSN:
1573-5117
Keywords:
Arctic
;
chemistry
;
Cornwallis Island
;
heliothermic
;
hypersaline water
;
ice
;
lake
;
meromixis
;
mesothermic
;
permafrost
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
Notes:
Abstract Garrow Lake (75° 23′ N; 96° 50′ W), located 3 km from the southern tip of Little Cornwallis Island and 6.7 m above mean sea level, is a meromictic ecto-creno-cryogenic lake with an area of 418 ha and a maximum water depth of 49 m. The thermal stratification of this lake is mesothermic (heliothermic). Some of the solar energy that penetrates through the 2 m ice cover is stored for a long period of time in the upper level of the monimolimnion, under a greenhouse effect due the water density gradient. The energy transfer (0.06 °C m −1) by conduction toward the bottom sediments is very constant from one year to the next and is likely to prevent the presence of permafrost under this water body. In its chemical composition, this meromictic lake is quite comparable to the world's saltiest water bodies and is the first lake, with a salinity greater than sea water to be reported for the Canadian Arctic. Its anoxic monimolimnion is nearly three times (90‰) as salty as normal sea water. This hypersaline water seems to have been derived from isostatic trapped marine waters within the present lacustrine basin as well as from underground during deglaciation of the area. The subsequent freezing-out of salt from the underground waters and the migration and accumulation of these waters in the bottom of Garrow Lake through a talik within the permafrost were the main contributing factors. The speed of formation and migration of the underground brine was a function of the postglacial isostatic uplift rate as well as the permafrost growth rate.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00031624
Permalink
