The lower limit of mountain permafrost in the Russian Altai Mountains

• Published in: Permafrost and Periglacial Processes
• Main Authors: Fukui, Kotaro, Fujii, Yoshiyuki, Mikhailov, Nikolai, Ostanin, Oleg, Iwahana, Go
• Format: Article in Journal/Newspaper
• Language: English
• Published: Wiley 2007
• Subjects: Ice; permafrost; Permafrost and Periglacial Processes; wedge*
• Online Access: http://dx.doi.org/10.1002/ppp.585; https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1002%2Fppp.585; https://onlinelibrary.wiley.com/doi/pdf/10.1002/ppp.585

Abstract Permafrost‐indicator features, such as rock glaciers, pingos and ice‐wedge polygons, exist at many locations in and around the South Chuyskiy Range of the Russian Altai Mountains (∼50°N). The distribution of these features suggests that the altitudinal range of the sporadic/patchy permafrost zones and the widespread discontinuous/continuous permafrost zones are 1800–2000 m ASL and above 2000 m ASL, respectively. The lower limit of discontinuous permafrost is approximately 200 m lower than in the Mongolian Altai, which are at a similar latitude. Cold air drainage and/or temperature inversions during winter within U‐shaped valleys together with a thin snow cover because of low precipitation during the same season likely cause the lower permafrost limit in the study area. The calibrated 14 C ages of tree remnants found in a rock glacier front in the lower Akkol valley were 293 ± 21 years BP and 548 ± 21 years BP. Given the time of emergence from beneath the Sofiyskiy glacier, this rock glacier developed between 3800–2600 and 550 years BP. Copyright © 2007 John Wiley & Sons, Ltd.