Earth’s Cryosphere, 2017, Vol. XXI, No. 1, p. 41-51
FROST MOUNDS OF BELY ISLAND IN COASTAL MARINE SETTINGS OF THE KARA SEA
P.T. Orekhov1, K.A. Popov1, E.A. Slagoda1,2,3, A.N. Kurchatova1,3, Ya.V. Tikhonravova1, O.L. Opokina1,3, G.V. Simonova4, V.N. Melkov4
1 Earth Cryosphere Institute, SB RAS, 86, Malygina str., Tyumen, 625026, Russia; orekhov.eci@gmail.com, eslagoda@ikz.ru
2 Tyumen State University, 6, Volodarskogo str., Tyumen, 625003, Russia
3 Industrial University of Tyumen, 38, Volodarskogo str., Tyumen, 625000, Russia
4 Institute of Monitoring of Climatic and Ecological Systems, SB RAS, 10/3, Academichesky ave., Tomsk, 634055, Russia
This paper presents the pioneering study of the morphology and structure of frost mounds on Bely Island in the Kara Sea, which also includes radiocarbon dating of peat and determinations of carbon isotope composition of peat and gas inclusions in ice, crystalline structure of ice, and sediment particle size distributions. By their shape, the identified frost mounds are grouped into cone-shaped, toroid-shaped, thaw-weakened frost mounds crosscut by polygonal network, and perennial flat-topped palsas with ice core. Modern palsas are distributed in laida zones regularly flooded by sea waters. Cone- and toroid-shaped frost mounds represent relict permafrost landforms developed in the Late Holocene. Relict frost mounds in Western Yamal and on the Arctic islands can indicate coastal-marine settings of their growth on low elevations in the Late Holocene.
Palsa, thaw-weakened frost mounds, age of peat, gas composition, crystalline structure of ice, granulometric composition of sediments