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Landforms in Norway indicating present and former permafrost have been compiled in order to discuss Holocene landform development patterns. In total 307 permafrost landforms have been mapped, consisting of rock glaciers and ice-cored moraines. The landforms were classified as active/inactive (intact) or relict landforms, and by origin. In northern Norway, permafrost landforms exist down to sea level and the majority of the landforms are relict talus-derived rock glaciers. In southern Norway, permafrost landforms are restricted to high elevations and the majority of the landforms are connected to glacial activity and classified as active. In the present paper, this contrasting pattern is interpreted to reflect that different processes leading to a permafrost landform also represent different ages and climatic regimes during their formation. The inventoried landforms reproduce the modelled permafrost distribution for Norway satisfactorily.

Knowledge of the characteristics and spatial distribution of permafrost in Iceland is important to understanding slope stability, climate change impacts and palaeo‐glaciology. The permafrost distribution there, however, is poorly constrained. The presence of rock glaciers and stable ice‐cored moraines in mountain settings relates to permafrost, making such landforms indicators of present or past permafrost. This study combines recently published aerial photographs (2002–07), radar interferometry based on Advanced Land Observing Satellite phased array type L‐band synthetic aperture radar (ALOS PALSAR) data (2007), land surface temperatures estimated from moderate‐resolution imaging spectroradiometer satellite data (MODIS; 2003–10) and field mapping to re‐examine the permafrost distribution, thermal characteristics and dynamics on the Tröllaskagi peninsula. An inventory of 265 landforms, mostly active or inactive (intact), categorised them by genesis and activity, the latter independently investigated by PALSAR interferometry. Intact landforms are mainly glacigenic, occurring as moraine‐derived rock glaciers or ice‐cored moraines. Their dominant orientation is between north and northeast, suggesting that topography and exposure influence their present‐day formation. Permafrost landforms exist at all elevations on the Tröllaskagi peninsula, with intact landforms at high elevations and relict landforms reaching down to sea level. Rock glaciers at sea level may imply early deglaciation of northern Iceland. Copyright © 2013 John Wiley & Sons, Ltd.

The presence of ground ice in Arctic soils exerts a major effect on permafrost hydrology and ecology, and factors prominently into geomorphic landform development. As most ground ice has accumulated in near-surface permafrost, it is sensitive to variations in atmospheric conditions. Typical and regionally widespread permafrost landforms such as pingos, ice-wedge polygons, and rock glaciers are closely tied to ground ice. However, under ongoing climate change, suitable environmental spaces for preserving landforms associated with ice-rich permafrost may be rapidly disappearing. We deploy a statistical ensemble approach to model, for the first time, the current and potential future environmental conditions of three typical permafrost landforms, pingos, ice-wedge polygons and rock glaciers across the Northern Hemisphere. We show that by midcentury, the landforms are projected to lose more than one-fifth of their suitable environments under a moderate climate scenario (RCP4.5) and on average around one-third under a very high baseline emission scenario (RCP8.5), even when projected new suitable areas for occurrence are considered. By 2061–2080, on average more than 50% of the recent suitable conditions can be lost (RCP8.5). In the case of pingos and ice-wedge polygons, geographical changes are mainly attributed to alterations in thawing-season precipitation and air temperatures. Rock glaciers show air temperature-induced regional changes in suitable conditions strongly constrained by topography and soil properties. The predicted losses could have important implications for Arctic hydrology, geo- and biodiversity, and to the global climate system through changes in biogeochemical cycles governed by the geomorphology of permafrost landscapes. Moreover, our projections provide insights into the circumpolar distribution of various ground ice types and help inventory permafrost landforms in unmapped regions.

Abstract. Rock glaciers are geomorphological expressions of permafrost. Close to sea level in northernmost Norway, in the subarctic Nordkinn peninsula, we have observed several rock glaciers that appear to be active now or were active in the recent past. Active rock glaciers at this elevation have never before been described in Fennoscandia, and they are outside the climatic limits of present-day permafrost according to models. In this study, we have investigated whether or not these rock glaciers are active under the current climate situation. We made detailed geomorphological maps of three rock glacier areas in Nordkinn and investigated the regional ground dynamics using synthetic aperture radar interferometry (InSAR). One of the rock glaciers, namely the Ivarsfjorden rock glacier, was investigated in more detail by combining observations of vertical and horizontal changes from optical images acquired by airborne and terrestrial sensors and terrestrial laser scans (TLSs). The subsurface of the same rock glacier was investigated using a combination of electrical resistivity tomography (ERT) and refraction seismic tomography (RST). We also measured ground surface temperatures between 2016 and 2020, complemented by investigations using an infrared thermal camera, and a multi-decadal climatic analysis. We mapped the rock glaciers in the innermost parts of Store and Lille Skogfjorden as relict, while the more active ones are in the mouths of both fjords, fed by active talus in the upper slopes. Several of the rock glaciers cross over both the Younger Dryas shoreline (25 m a.s.l.) and the Early to Mid-Holocene shoreline at 13 m a.s.l. Both InSAR and optical remote sensing observations reveal low yearly movement rates (centimetres to millimetres per year). The ERT and RST suggest that there is no longer permafrost and ground ice in the rock glacier, while temperature observations on the front slope indicate freezing conditions also in summer. Based on the in situ temperature measurements and the interpolated regional temperature data, we show that the mean annual air temperature (MAAT) of the region has risen by 2 ∘C since the late 19th century to about 1.5 ∘C in the last decade. MAATs below 0 ∘C 100–150 years ago suggest that new rock glacier lobes may have formed at the end of the Little Ice Age (LIA). These combined results indicate that the Nordkinn rock glaciers are transitioning from active to relict stages. The study shows that transitional rock glaciers are still affected by creep, rock falls, snow avalanches, etc., and are not entirely dynamically dead features. Our contrasting results concerning permafrost presence and rock glacier activity show the importance of a multi-methodological approach when investigating slope processes in the edge zones of permafrost influence.