Solifluction rates and environmental controls at local and regional scales in central Austria

Abstract

Solifluction is a widespread periglacial phenomenon. Little is known about present solifluction rates in Austria. The author monitored five solifluction lobes during a four-year period. Annual rates of surface velocity, vertical velocity profiles, depths of movement, and volumetric velocities were quantified using near-surface markers and painted lines. Environmental conditions were assessed using air temperature, soil texture, and ground temperature-derived parameters. The latter were used to estimate the relevance of needle-ice creep, diurnal frost creep, annual frost creep, and gelifluction. The mean surface velocity rates were 3.5–6.1 cm yr−1 (near-surface markers) and 6.2–8.9 cm yr−1 (painted lines), respectively, indicating a high relevance of needle-ice creep. The mean depth of movement was 32.5–40 cm. The mean volumetric velocities were 71–102 cm3 cm−1 yr−1. Solifluction rates at the five sites did not correlate with each other due to site-specific controls. No statistically significant correlations were quantified between solifluction rates and different environmental parameters due to data gaps and short time series, thus highlighting the importance of long-term monitoring. Nevertheless, the results suggest that longer zero curtain periods, longer seasonal ground thawing periods, later start of the seasonal snow cover, more freeze-thaw cycles, and cooler early summer temperatures promote solifluction.

The summer heatwave in 2022 and its role in changing permafrost and periglacial conditions at a historic mountain pass in the Eastern Alps (Hochtor, Hohe Tauern Range, Austria)

“…Solifluction rate data are not known from the Hochtor site. As judged from field‐based measurements at a nearby site (surface velocity rates of 3.5 cm/year 26 ), we can assume a maximum relative misplacement of individual electrode positions between 2019 and 2022 in the order of a maximum of 10 cm. This minor change in the position is considered irrelevant if compared to, for instance, those of active rock glaciers 61 …”

“…At the nearby Fallbichl site (1.8 km to the south of Hochtor), surface velocity rates of 3.5 cm/year have been measured at a large turf-banked lobe. 26 The former track of Roman age over the 6 ; glacier. 7 pass was destroyed at solifluction-affected areas on both sides of the mountain pass, 15 particularly north-west of the Hochtor near the Knappenstube area where up to 50 m wide and more than 100 m long solifluction lobes dominate the slope morphology (Figure 4).…”

“…Because a distinct seasonal winter snow cover at the GT monitoring site is absent over the entire winter due to wind-related snow redistribution from the ridge towards south, forming a cornice (Figure 3A,B 26 or the Swiss Alps. 56 Estimations of the annual freezing and thawing depths between 2010 and 2022 support the measured GT data.…”

Tracking denudation and sediment production and transport with cosmogenic 10Be in arid, high‐altitude Himalayan half‐grabens, Zanskar, northern India

“…These calculated average erosion rates are consistent with sediment high up in the catchment being transported downslope and then stagnating on the lower slopes, supporting the interpretation that sediment 10 Be concentrations better record transport time than steady‐state erosion. In similar arid alpine environments, rates of downslope movement of gelifluction lobes are typically on the order of tens of mm/a (Ridefelt et al ., 2009; Kellerer‐Pirklbauer, 2018) although rates of sediment transport across very low gradient desert piedmont landscapes through ephemeral channel networks can be two or three orders of magnitude greater over timescales of 10 3–5 years (Nichols et al ., 2002, 2005).…”

Advances in understanding the cooling rates and bending of needle ice: Photogrammetric and thermal observations leading to the spatial distribution of needle ice creep

“…It is for this reason that the climatic control on periglacial soil processes needs to be analyzed (Matsuoka, 2011). Needle ice phenomenon is widespread worldwide, for instance, Maritime Subantarctica (Boelhouwers, Holness, & Sumner, 2003; Haussmann, Boelhouwers, & Mcgeoch, 2009; Holness, 2004; Nel & Boelhouwers, 2014), the United Kingdom (Ballantyne, 1996), Alaska (Gartner, Chapin Iii, & Shaver, 1986), South Africa (Grab, 2001, 2002), Canada (Mackay & Mathews, 1974), Japan (Matsuoka, 1998b, 1998a) and Austria (Kellerer‐Pirklbauer, 2018).…”