Geochemical, lithological, and geochronological characteristics of sediment samples from Yedoma and thermokarst deposits, 1998-2016, Siberia (RU) and Alaska (US)

This dataset merges data from the yedoma domain in Northern Siberia (RU) and Alaska (US). It includes numerous fieldwork campaigns, which take place since 1998 . In total 224 samples from drained Thermokarst, basins and 736 Yedoma samples are included from 27 sites (17 Siberia, 10 Alaska). The laboratory methods are the following: Total organic carbon (TOC) samples were measured with a carbon-nitrogen-sulphur analyser (Elementar Vario EL III) or a TOC analyser (Elementar Vario Max C). For ice content measurement needed for bulk density calculation (bulkdens), samples were weighed in wet and ovendry state during field expeditions or dried in the lab using a freeze dryer. BD was then calculated using its inverse relationship with porosity (see Strauss et al 2013 for details)). Because pore volume is assumed to be ice saturated, the pore volume can be directly inferred from the segregated ice content. Ice content was determined by dying in the file already or with an freeze dryer in the lab. 14C dates were compiled from different sources given with locations in Table S1 in the supplement of Strauss et al 2017. Areal estimation of yedoma and degraded sites were done with literature estimates including general estimates in Strauss et al 2013. Data from local- and regional-scale analyses of Yedoma deposit versus thermokarst-affected areas (summarised in Strauss et al 2013) indicate that ~70% of the Yedoma region area is affected by degradation. The remaining Yedoma deposit extent is ~416,000 km2. We further estimate that ~10% of the Yedoma region is covered with lakes and rivers and thus underlain by unfrozen deposits (150,000 km2) and ~4% is covered with other deposits including deltaic and fluvial sediments (50,000 km2), leaving ~56% (775,000 km2) of the Yedoma region covered by frozen thermokarst deposits in drained thermokarst lakes.

Detailed information about the methods can be found in Strauss et al 2013 and 2017 and the supplements (https://doi.org/doi:10.1002/2013GL058088, https://doi.org/10.1016/j.earscirev.2017.07.007).