Abstract
In this paper changes in the active layer of the high arctic coastal area in north‐west pitsbergen, valbard are described. Analysis includes both the ground thawing depth and its near‐surface thermal structure. The study was conducted on the affiøyra lain (valbard) at several fixed sites, which represent places typical of the region: a sandy beach, a tundra plain and a moraine ridge. The results show that in recent years, at two measurement points a significantly deeper thawing was observed. In 1996–2012 on the beach and on the moraine the trend of active layer thickness change was +1.3 cm yr−1 and +2.5 cm yr−1, respectively. Generally, in the years 2008–2012 the mean thickness of the active layer in the affiøyra region increased by 3% to 6%. Even at the spatially close sites, within similar environments, there are significant differences in the thickness of the active layer. Measurements show that significant changes also occurred in the thawed ground temperature. Mean values of the observed near‐surface temperature in recent years (2007–2011) were higher by more than 1.0°C, in comparison to the mean in the late 1970s.
Acknowledgements
The authors wish to thank all the members of the polar expeditions to Svalbard for assistance in the field. Special gratitude goes to Sylwia Wąsowska‐Cypel for deposite texture of lithological profiles information. The authors would like to thank the anonymous reviewers for valuable comments and suggestions that helped to improve the paper.
Additional information
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Ireneusz Sobota
Ireneusz Sobota, Marcin Nowak, Faculty of Earth Sciences, Nicolaus Copernicus University, Lwowska 1, 87‐100 Toruń, Poland
E‐mail: [email protected]