Earth’s Cryosphere, 2023, Vol. XXVII, No. 2, p. 3-13.

GEOTHERMAL FIELDS AND THERMAL PROCESSES IN CRYOSPHERE

GROUND TEMPERATURE AT THE DEPTH OF ZERO ANNUAL AMPLITUDE IN THE AREA OF SUPRAPERMAFROST TALIKS IN CENTRAL YAKUTIA

L.S. Lebedeva1,*, N.E. Baishev1,  N.A .Pavlova1, V.S. Efremov1, V.V. Ogonerov1, A.M. Tarbeeva2

1 Melnikov Permafrost Institute, Siberian Branch of the Russian Academy of Sciences, Merzlotnaya St. 36, Yakutsk, 677010 Russia
2 Lomonosov Moscow State University, Faculty of Geography, Makkaveev Research Laboratory of Soil Erosion and Channel Processes, Leninskie Gory 1, Moscow, 119991 Russia
*Corresponding author; e-mail: lyudmilaslebedeva@gmail.com

Despite the low mean annual air temperature and low precipitation, subaerial suprapermafrost aquifer taliks are formed in some cases in the continuous permafrost zone of Central Yakutia. The paper presents an analysis of the seasonal and interannual dynamics of ground temperature in contrasting geocryological conditions – in areas of permafrost spread from the surface and in suprapermafrost subaerial taliks – of the key site Levaya Shestakovka 20 km southwest of Yakutsk. The permafrost table in this area occurs at depths from 0.5 to 20 m. The highest ground temperatures are typical of the aquiferous suprapermafrost taliks confined to gentle slopes composed of sandy sediments and covered with pine woodland. The thickness of the seasonally frozen layer reaches 3 m, and the depth of zero annual amplitudes varies from 6 to 12 m. Thawed deposits are preserved due to the continuous filtration of groundwater in them. The lowest ground temperatures are characteristic of the mire and the river floodplain. The depth of seasonal thawing varies from 0.5 to 1.0 m, and the depth of zero annual amplitudes exceeds 15 m. In recent years, slow freezing of the taliks from below has been noted due to mild cooling of the strata underlying the thawed aquifers. Beyond the area of taliks, weak multidirectional changes in ground temperature have been recorded.

Keywords: suprapermafrost taliks, temperature at the depth of zero annual amplitude, Central Yakutia, sand deposits, groundwater, seasonally thawed layer, seasonally frozen layer, continuous permafrost

Recommended citation: Lebedeva L.S., Baishev N.E., Pavlova N.A., Efremov V.S., Ogonerov V.V., Tarbeeva A.M., 2023. Ground temperature at the depth of zero annual amplitude in the area of suprapermafrost taliks in Central Yakutia. Earth’s Cryosphere XXVII (2), 3–13.