ALBERT

Description: This work summarizes the archived data of geocryological and hydrogeological conditions in the west of Nordenskiold Land on the Spitsbergen Archipelago. The historical data obtained in the Soviet period during coal exploration are reviewed together with the results of our own studies performed as part of the Russian Scientific Arctic Expedition on Spitsbergen (RAE-S) in 2016–2020. With respect to geocryology, the region is assigned to the zone of continuous permafrost. The thickness of rocks and sediments with temperatures below zero is about 100 m near the coast and increases to 540 m on watersheds. The mean annual ground temperature near the zero-amplitude depth varies from –3.6 to –2.2°C. Below this layer, the temperature curve in the top part of the section tends to deviate toward positive temperatures, reflecting the modern cycle of climate warming. From the hydrogeological point of view, the area belongs to the marginal zone of the West Spitsbergen cryoadartesian basin. Seawater intrusions near the coast form saline subpermafrost aquifers, including those with temperatures below zero, reflecting the seawater (sodium chloride) composition and hydraulic heads close to sea level. Fresh and slightly saline (sodium bicarbonate on the east coast of Grønfjorden and magnesium–calcium sulfate in gypsum-bearing deposits on the west coast) subpermafrost water with hydraulic heads reaching 100 m above sea level is fed by water-saturated ice in the deep layers of large glaciers.

Description: This report follows up on the report published in the SESS Report 2018 (Christiansen et al. 2019). Since 2018, the Norwegian Environment Agency has released the Climate in Svalbard 2100 report summarizing observed trends in permafrost conditions over the period of field measurements and a forecast for the future, based on recent climate and permafrost modelling (Hanssen-Bauer et al. 2019). It is well established that the terrestrial cryosphere in Svalbard has changed since modern permafrost monitoring efforts began in the late 1990s. In central Svalbard in the Adventdalen area, ground temperatures have risen by as much as 0.15°C per year (10 m depth) and the thickness of the seasonally-unfrozen active layer increased by 0.6 cm per year since 2000 in sediments and 1.6 cm/year in bedrock (Hanssen-Bauer et al. 2019), while in Ny-Ålesund ground temperatures increased by 0.18°C/year and the thickness of active layer increased by 5 cm/year (Boike et al. 2018). Modern monitoring techniques mean that it is relatively easy to quantify permafrost change in terms of temperature. The visible effects of warming permafrost are, however, more ambiguous. A prolonged thaw season is anticipated to result in a thicker active layer, and increased rainfall intensity can result in more frequent landslides. The strength of frozen soil decreases when warming and permafrost change may expectedly result in infrastructure problems in cases where climate change was not considered during the initial design. The aims of this part of the State of Environmental Science in Svalbard reporting are to: (1) provide an overview of permafrost data collected during the 2017-2018 hydrological year (1 September 2017 – 31 August 2018), (2) contrast these results with the 2016-2017 hydrological year as presented in Christiansen et al. (2019), (3) summarise developments in permafrost monitoring in Svalbard, and (4) provide recommendations for future permafrost investigations. Understanding the spatial distribution of permafrost conditions is critical to predicting geomorphological change and understanding the variability in climate impacts. 23710

Description: The observed mean annual permafrost temperature data for the period 2016-2019 at 10-20 m depths show a range from no warming in the Adventdalen, Ny-Ålesund and Barentsburg areas, up to 0.15°C/yr warming in inner Adventdalen at Janssonhaugen. This shows that there is still a response to the general warming that Svalbard has seen over the last decades. During the observation period, the mean annual air temperature declined by 0.6°C, with a particular cooling in the autumns. There was a clear reduction in the amount of precipitation of 100 mm. This caused the top permafrost temperature to decrease at all observation sites ranging from 0.2°C/yr at Kapp Linné to 0.6°C/yr in Barentsburg. The active layer has mostly decreased slightly in thickness over the 2016-2019 period from 1 cm/yr in Ny-Ålesund to 6.5 cm/yr in Adventdalen, while two sites had small increases, 1 cm/yr at Kapp Linne and 3.5 cm/yr at Janssonhaugen. In the blockfield at Breinosa the active layer doubled to 98 cm, while in raised marine sediments in Barentsburg the active layer thinned by 18.5 cm/yr from summer 2017 to summer 2019. The ground ice content in the Svalbard permafrost observation boreholes is largest in the permafrost in valley bottom sediments, up to 160% (relative to dry weight), with much less ice in the bedrock sites, typically below 15%. In Adventdalen the permafrost has a much higher content of ground ice, reaching 150% in the top 1-3 m, where terrestrial sediments such as loess and solifluction sediment dominate, and clearly lower ice content ~25-30% in the fluvial and marine sediments below. The overview of the drilling equipment demonstrates clearly that Svalbard is now well-equipped for drilling boreholes with a range of equipment, allowing creation of both deep and shallow boreholes. The review of the drilling methods used for the existing observation boreholes shows that most of them, even though made for permafrost observation, did not collect cores, and some do not even have any stratigraphical record.