Figure 1.

Location of the study sites. (a) Potential [after Romanovskii, ¹⁹⁹³] and fragmented [Jorgenson et al., ²⁰⁰⁸; Grosse et al., ²⁰¹³] area of Yedoma deposits in Arctic and sub-Arctic lowlands, including the studied thermokarst deposit areas. Sites are numbered; 1, Cape Mamontov Klyk; 2, Nagym Island; 3, Khardang Island; 4, Kurungnakh Island; 5, Bykovsky Peninsula; 6, Muostakh Island; 7, Buor Khaya Peninsula; 8, Stolbovoy Island; 9, Bel'kovsky Island; 10 and 11, Kotel'ny Island; 12, Maly Lyakhovsky Island; 13, Bol'shoy Lyakhovsky Island; 14, Cape Svyatov Nos; 15, Oyogos Yar; 16, Kytalyk; 17, Duvanny Yar; 18, Kitluk River; 19, Vault Creek tunnel; 20, Dalton Highway; 21, Itkillik River; 22, Colville River; and 23, Camden Bay. For site 18, only thermokarst deposit samples are available, resulting in 22 Yedoma and 10 thermokarst deposit sites. (b) A panchromatic Landsat-7 image of the wintery Svyatoy Nos and Shirokostan peninsulas (12 March 2012, extent of the white box shown in a), illustrating several granite domes mantled by Yedoma deposits and strong dissection by thermokarst depressions (Landsat data source: USGS EROS Data Center). The black box marks the location of the area shown in Figure 2b.