/* DATA DESCRIPTION: Citation: Dereviagin, Alexander Yu; Meyer, Hanno; Chizhov, Alexander B; Hubberten, Hans-Wolfgang; Simonov, Eugeniy F (2002): Isotopic composition of modern ice wedges and winter precipitation in the Laptev Sea region (Table 2). PANGAEA, https://doi.org/10.1594/PANGAEA.418311, Supplement to: Dereviagin, AY et al. (2002): New data on the isotopic composition and evolution of modern ice wedges in the Laptev Sea region. Polarforschung, 70, 27-35, hdl:10013/epic.29856.d001 Abstract: The first step for the application of stable isotope analyses of ice wedges for the correct paleoclimatic reconstruction supposes the study of the isotopic composition of modern ice wedges and their relationship with the isotopic composition of modern precipitation. The purpose of this research is to present, to analyze and to discuss new data on isotopic composition (d18O, dD, 3H) of modern ice wedges obtained in the Laptev Sea region in 1998-99. Investigations were carried out at two sites: on Bykovsky Peninsula in 1998 and on Bol'shoy Lyakhovsky Island in 1999 and were based on the combined application of both tritium CH) and stable isotope (d18O, dD) analyses. Tritium analyses of the atmospheric precipitation collected during two field seasons show seasonal variations: high tritium concentration in snow (to a maximum of 207 TU) and low values of tritium concentration (<20 TU) in rain. High tritium concentrations are also observed in the surface water, in suprapermafrost ground waters, and in the upper part of permafrost. High tritium concentrations range between 30-40 TU and 750 TU in the studied modern ice wedges (active ice wedges), which let us believe that they are of modern growth. Such high tritium concentrations in ice wedges can not be associated with old thermonuclear tritium because of the radioactive decay. High tritium concentrations found in the snow cover in 1998/99, in the active layer and in the upper part of permafrost give evidence of modern (probably the last decade) technogenic tritium arrival from the atmosphere on to the Earth surface in the region. The comparison of the isotopic composition (d18O, dD and d-excess) of active ice wedges and modern winter precipitation in both sites shows: 1) the isotopic composition of snow correlates linearly with a slope close to 8.0 and parallel to the GMWL at both sites; 2) the mean isotopic composition of active ice wedges on Bykovsky Peninsula is in good agreement with the mean isotopic composition of modern snow; 3) the isotopic composition of active ice wedges and snow on Bol'shoy Lyakhovsky Island are considerably different. There are low values of d-excess in all studied active ice wedges (mean value is about 4.8 per mil), while in snow, the mean value of d-excess is about 9.5 per mil. Possible reasons for this gap are the following: 1) the modification of the isotopic composition in snow during the spring period; 2) changes in the isotopic composition of ice wedges due to the process of ice sublimation in open frost cracks during the cold period; 3) mixing of snowmelt water with different types of surface water during the spring period; 4) different moisture source regions. Project(s): Laptev Sea System (LSS) (URI: https://www.transdrift.info) Coverage: MEDIAN LATITUDE: 72.787614 * MEDIAN LONGITUDE: 124.748086 * SOUTH-BOUND LATITUDE: 71.000000 * WEST-BOUND LONGITUDE: 100.000000 * NORTH-BOUND LATITUDE: 75.000000 * EAST-BOUND LONGITUDE: 141.500000 Parameter(s): LATITUDE (Latitude) * GEOCODE LONGITUDE (Longitude) * GEOCODE Area/locality (Area) * PI: Dereviagin, Alexander Yu Reference/source (Reference) * PI: Dereviagin, Alexander Yu δ18O, water [‰ SMOW] (δ18O H2O) * PI: Dereviagin, Alexander Yu * COMMENT: ice wedges δ18O, water [‰ SMOW] (δ18O H2O) * PI: Dereviagin, Alexander Yu * COMMENT: snow δ18O, minimum [‰] (δ18O min) * PI: Dereviagin, Alexander Yu * COMMENT: ice wedges δ18O, minimum [‰] (δ18O min) * PI: Dereviagin, Alexander Yu * COMMENT: snow δ18O, maximum [‰] (δ18O max) * PI: Dereviagin, Alexander Yu * COMMENT: ice wedges δ18O, maximum [‰] (δ18O max) * PI: Dereviagin, Alexander Yu * COMMENT: snow Temperature, mean winter [°C] (T win) * PI: Dereviagin, Alexander Yu License: Creative Commons Attribution 3.0 Unported (CC-BY-3.0) (URI: https://creativecommons.org/licenses/by/3.0/) Size: 54 data points */ Latitude Longitude Area Reference δ18O H2O [‰ SMOW] (ice wedges) δ18O H2O [‰ SMOW] (snow) δ18O min [‰] (ice wedges) δ18O min [‰] (snow) δ18O max [‰] (ice wedges) δ18O max [‰] (snow) T win [°C] 71.0000 133.0000 Yana River mouth Konyakhin 1988 -21.3 -19.7 -23.2 -21.8 71.6300 128.8700 Tiksi Vasil chuk 1992 -22.8 -21.8 -24.6 -21.2 72.0000 100.0000 Taymyr, Labaz Lake Chizhov et al. 1997 -23.0 -23.9 -19.8 -23.4 -25.5 -26.0 -23.5 72.0000 129.3333 Bykovsky site this study -25.4 -23.2 -22.5 -19.7 -26.5 -27.5 -22.9 73.3333 141.5000 Lyakhovsky site this study -21.0 -26.9 -19.2 -17.9 -22.5 -31.4 -20.6 74.5500 100.5333 Taymyr, Cape Sabler Dereviagin et al. 1999 -20.4 -24.8 -20.1 -21.1 -20.6 -28.4 -20.8 75.0000 140.0000 Novaya Sibir Island Konyakhin 1988 -18.3 -15.0 -21.8 -18.5