Periglacial Areas Research Articles

Assessment of Human Health Risk Indices Due to Metal Contamination in the Surface Water of the Negro River Sub-Basin, Áncash.

The accelerated loss of glacial cover in the Cordillera Blanca in Áncash, Peru, exposes the underlying rocks with high concentrations of sulfides from the Chicama Formation to oxidation and leaching processes, generating acid rock drainage (ARD) in glacial and periglacial areas. These are transported by surface runoff, contaminating the surface water with high concentrations of metals and sulfates, as well as increasing the acidity, which poses a risk to human health and the ecosystem. Therefore, the risk indices for human health due to metal contamination were evaluated at 19 surface water sampling points distributed in the Río Negro sub-basin. Hydrochemical analyses revealed average metal concentrations in the following order: Fe (28.597 mg/L), Al (3.832 mg/L), Mn (1.085 mg/L), Zn (0.234 mg/L), Ni (0.085 mg/L), Co (0.053 mg/L), Li (0.036 mg/L), Cu (0.005 mg/L), and Pb (0.002 mg/L). The risk was determined by calculating the Heavy Metal Pollution Index (HPI) and the Hazard Index (HI). The average HPI value was 360.959, indicating a high level of contamination (HPI ≥ 150). The human health risk assessment indicated that adverse effects caused by iron, lithium, and cobalt in children and adults should be considered. Through the use of Pearson correlation analysis, principal component analysis, and cluster analysis, it was identified that SO42-, Fe, S, Al, Co, Mn, Ni, Zn, and Li originate from natural sources, associated with the generation of ARD in glacial and periglacial areas.

TESTING OPTICAL SPECTRAL INDICES FOR ASSESSMENT OF SURFACE CHANGES DUE TO PERMAFROST MELTING ON LIVINGSTON ISLAND, ANTARCTICA

The present study aims to examine the potential of optical satellite data and spectral indices to assess surface changes induced by permafrost melting. Surface changes related to permafrost melting on Livingston Island, Antarctica were examined using optical satellite data from Sentinel-2 sensors of the European Space Agency (ESA). The study area coincides with previous field studies by electrical resistivity tomographic profiles made to establish and visualize the presence of permafrost. Utilizing the advantages of remote sensing methods and calculation of optical indices, it was tracked whether and to what extent there was a surface change and melting of the permafrost in the study area. The observation period encompasses the astral summer seasons from 2016 to 2023. The results show that the combination of different optical indices gives a better understanding of changes in the terrain. The combined use of the Normalized Difference Glacier Index (NDGI), Normalized Difference Snow Index (NDSI), Normalized Difference Snow and Ice Index (NDSII), Normalized Difference Water Index (NDWI), Normalized Difference Vegetation Index (NDVI), and Moisture Stress Index (MSI) indicates for a pronounced trend of melting of the active layer of the permafrost periglacial area of research in March 2016 and 2017, and from January to mid of March 2023.

Sources and pathways of mercury in soils from Antarctic periglacial areas

The Antarctic plays a critical role in global mercury cycling as both a sink of Hg and, in response to rapid global warming, an emerging source of Hg through its release from thawing permafrost and recessing glaciers. At the present time, Antarctica and surrounding areas have little mercury contamination in comparison to other regions of the world. Understanding the sources and transformations of Hg in the Antarctic will be particularly important in predicting the role of a changing environment in the mercury cycle as emissions and global climate change. Study samples were collected at 12 stations, categorized into three groups based on the human or animal presence and flora. Sampling took place in December 2018 and January 2019, and soil and parent rock samples were collected and analyzed for total mercury concentration and its fractions using atomic absorption spectroscopy. Bedrock samples collected on the coast of Admiralty Bay were found to have low organic matter content, while soil samples from the west shore of the bay had a high variability of organic matter content, ranging from 3 % to 41 %. The concentration of total mercury in bedrock ranged from 2.1 ng/g to 15.0 ng/g, and in soil samples, the total mercury concentration ranged from 4.7 ng/g to 143.1 ng/g. This paper reviews current knowledge of Hg cycling in the Antarctic, including its sources, fate, and effects on the ecosystem. The implications of climate change for Hg cycling in the region are also discussed, highlighting the need for continued research to better understand the potential impacts of Hg contamination in the Antarctic.

Limited extension of the MIS 2 proglacial lake in the Severnaya Dvina valley, south‐eastern margin of the last Scandinavian Ice Sheet

ABSTRACTThe Severnaya Dvina River valley crosses the former south‐eastern margin of the last Scandinavian Ice Sheet. Despite a long research history, there remains considerable controversy about the maximum ice‐sheet extent and the expansion of proglacial lakes within the Severnaya Dvina fluvial system. The goal of this study was to address these issues using new material from the valleys of the Severnaya Dvina and the lower Vychegda, thereby contributing to an understanding of the history of the south‐eastern sector of the last Scandinavian Ice Sheet and its periglacial areas. We studied a number of geological sections using radiocarbon and optically stimulated luminescence (OSL) dating, pollen and carpological analyses, and found that the Last Glacial Maximum (LGM) proglacial lake occupied the Severnaya Dvina valley between 20–19 ka and about 15.5 ka. The lake was localized within the proglacial isostatic depression and occupied only the Severnaya Dvina valley extending no further than the confluence of the Vychegda River, no more than 110 km from the edge of the ice sheet. The lake formation did not cause any drainage reorganization within and outside the Vychegda fluvial system. Given the small size of the lake and presence of the oldest OSL ages along the entire length of the former lake, we suggest that the onset of the proglacial lake marks the maximum extent of the ice sheet in the area. Consequently, the onset of the local LGM may be dated to 20–19 ka, somewhat earlier than assumed by most previous researchers. The LGM ice sheet boundary was located in the Severnaya Dvina valley downstream from the Vychegda confluence and did not extend into the Vychegda valley, despite previous suggestions. During deglaciation, the lake disappearance together with crustal rebound caused an incision episode in the Vychegda – Severnaya Dvina system and the formation of the Lateglacial alluvial terrace with relative height rising downstream due to the uneven rates of the postglacial uplift.

Hydrometeorological triggering of periglacial debris flows using a Bayesian approach: a case study of the Hailuogou Gully region, China

Many debris flows have occurred in small basins with a small glacier cover or snow cover in periglacial areas, suddenly caused high mortality and great damage. The hydrometeorological conditions that caused such debris flows are complex, making forecasting and early warning difficult. Previous studies for these small-glacial-covered basins have primarily considered rainfall as the only inducing factor of debris flows, and often the effects of temperature are neglected. Thus, we carried out a probabilistic analysis of variables derived from hydrometeorological factors for the Mount Gongga region, Sichuan, China, where debris flows were recorded on 14 days between 1988 and 2019. By analyzing hydrological characteristics when debris flows occurred, three distinct dominant trigger types could be identified. The results show that seven (50%) of the observed debris flow events during the study period, high-intensity rainfall was the dominant trigger, snowmelt by high temperature was identified as the dominant trigger for 2 (14%). Furthermore, five (36%) debris flow events could be attributed to the combined effects of long-lasting (or short-medium) rainfall and sustained higher temperatures. We find that the differences between the trigger types are statistically significant, and a susceptibility prediction differentiating between trigger types can outperform simple rainfall-only situations. This study contributes to an improved understanding of the hydrometeorological impact on debris flow initiation in high elevation watersheds.

Thermal monitoring of a Cryosol in a high marine terrace (Half Moon Island, Maritime Antarctica).

Active layer and permafrost are important indicators of climate changes in periglacial areas of Antarctica, and the soil thermal regime of Maritime Antarctica is sensitive to the current warming trend. This research aimed to characterize the active layer thermal regime of a patterned ground located at an upper marine terrace in Half Moon Island, during 2015-2018. Temperature and moisture sensors were installed at different soil depths, combined with air temperature, collecting hourly data. Statistical analysis was applied to describe the soil thermal regime and estimate active layer thickness. The thermal regime of the studied soil was typical of periglacial environment, with high variability in temperature and water content in the summer, resulting in frequent freeze-thaw cycles. We detected dominant freezing conditions, whereas soil temperatures increased, and the period of high soil moisture content lasted longer over the years. Active layer thickness varied between the years, reaching a maximum depth in 2018. Permafrost degradation affects soil drainage and triggers erosion in the upper marine terrace, where permafrost occurrence is unlikely. Longer monitoring periods are necessary for a detailed understanding on how current climatic and geomorphic conditions affect the unstable permafrost of low-lying areas of Antarctica (marine terraces).

Influence of the modern climatic setting in the mountains of Central Asia on the state of glaciation, glacier runoff and glacial lake outbursts

The climatic setting of Central Asia in the second half of the 20th century and in the first decade of the 21st century is characterized by a change of horizontal and vertical temperature gradients at the western periphery of the Central Asian Mountain system. The growth of summer air temperatures led to the decrease of mountain glaciations. In the last 45 years the glaciers in selected catchments of Gissar-Alay lost about 16% in area while the glaciers of the Pskem river catchment lost 27% in area. The river regimes, primarily the annual distribution of runoff react to the glacier decrease. The share of glacial runoff is over 25% in years with little precipitation, while it considerably decreases in years with abundant precipitation. One of the negative consequences of the glacier decrease is the formation of lakes in the periglacial area. The state of glacial lakes should be monitored, because they may pose outburst debris flow hazard.

Insight into geotechnical properties of glacial tills in a periglacial area, Southeast Tibet

Insight into geotechnical properties of glacial tills in a periglacial area, Southeast Tibet

Soil organic carbon stocks in mountain periglacial areas of northern Patagonia (Argentina)

ABSTRACT This study presents a detailed soil organic carbon (SOC) inventory for two areas in the mountain periglacial zone of northern Patagonia (altitude range c. 1,400–2,100 m). We describe plant cover and soil profiles at twenty-seven sites representing the main land cover classes and landform types at and above the treeline. The mean SOC 0–100 cm storage is 2.31 kg C m−2 for the combined study areas, which includes 69 percent of bare ground surfaces with negligible SOC stocks. If we consider the vegetated alpine belt only, mean SOC 0–100 cm storage increases to 6.96 kg C m−2. Solifluction has resulted in areas with dense plant cover and deep soil profiles with mean SOC 0–100 cm of 17.1 to 18.3 kg C m−2 and a maximum total stock of 51.5 kg C m−2. Lowest SOC storages of 0.13 to 0.63 kg C m−2 are found in bare and sparsely vegetated high-elevation areas with shallow and stony soils developed in patterned ground (stripes and sorted circles). Projected future increases in ambient temperature will likely result in an upward shift of the alpine vegetation belt with soil development, creating new areas of ecosystem carbon storage.

The Thickness of Talus Deposits in the Periglacial Area of SW Spitsbergen (Fugleberget Mountainside) in the Light of Slope Development Theories

Periglacial slopes are susceptible to recent climate change. The rate of morphogenetic processes depends on numerous factors. The most important of these is the warming of the air and ground, increased precipitation (extreme rainfall in particular), and the rate of snow cover decay. The dynamics of these processes may effectively modify contemporary slope development models. The paper shows the structure of selected talus slopes on a Fugleberget mountainside, based on field observations and radar (GPR) soundings. The results are then compared to classical slope models. The radar survey in April and May 2014 used a RAMAC CU II Malå GeoScience system equipped with a 30 MHz RTA antenna (Rough Terrain Antenna). Five GPR profiles of different lengths were obtained along the talus axes, transversally on Fugleberget and partly on the Hansbreen lateral moraine. According to the radar soundings, the maximum thickness of the debris deposits is 25–30 m. The thickness of the weathered material increases towards the talus cone’s terminal part, and debris deposits overlap marine sediments. The talus slopes’ morphometry shows that their current forms differ from standard slope models, which may be due to the significant acceleration of geomorphic processes resulting from climate change, including rapid warming in the last four decades.

Patterns of Benthic Communities in Arctic Fjords (Novaya Zemlya Archipelago, Kara Sea): Resilience vs. Fragility

Despite a large number of studies, a detailed overall picture of benthic communities zonation in the Arctic fjords is currently lacking. Our study aimed to find out whether there is a universal model for the distribution of benthic communities based on the structural features of the fjords. We examined benthic macrofaunal communities in fjords with various environmental settings on the eastern coast of Novaya Zemlya Archipelago, Kara Sea. The material was collected during five cruises undertaken from 2013 to 2016. A total of 50 stations located in the five fjords were taken. In all five fjords, macrofauna had a similar composition assembled from a regional species pool, with a predominance of species tolerant to glacial sedimentation and fluctuations in temperature and salinity. Benthic communities changed consistently along the axis of the bay from the outer slope to the inner parts. Biodiversity and quantitative characteristics of the macrofauna decreased along the environmental gradient related to terrigenous and glacial runoff, consistent with patterns reported in other studies of Arctic glacial fjords. The most impoverished communities were dominated by bivalvePortlandia arcticaand isopodSaduria sabini. At the same time, fjord walls and sills, characterized by low sedimentation rates, strong currents and the presence of ice-rafted debris, were inhabited by patchy distributed benthic communities dominated by species confined to hard substrates. In general, the distribution of communities corresponded to five zones: depleted inner periglacial areas, the upper subtidal belt with stony substrates, deep inner semi-isolated basin, outer non-isolated basins and upper slope transitioning to lower slope. Our study can provide a reference point for monitoring changes in fjord ecosystems in response to climate change and the potential impact of human activities.

Rock Glacier Dynamics by a Thermo-Elastic-Viscoplastic Constitutive Relationship

As a result of mountain permafrost creep, rock glaciers are common features in high-altitude periglacial areas. From a practical point of view, beyond their localization and inventorying, both the monitoring and prediction of their evolution due to climate changes are crucial. One of the effects of climate change is the thickening of the basal shear zone (the portion of the rock glacier where most deformations are localized), eventually leading to the development of unexpected and unprecedented (in terms of location, magnitude, frequency, and timing) instability phenomena. These phenomena bear consequences for the understanding of landscape evolution, natural hazards, and the safe and sustainable operation of high-mountain infrastructures. Most of the studies about active rock glaciers are focused on the analysis of monitoring data, while just a few studies are focused on modeling their behavior to understand their possible further evolution. The active rock glacier response is characterized by a viscous (rate-dependent) behavior, influenced by seasonal temperature oscillations, and characterized by a seasonal transition from slow to fast. In this work, a new thermo-mechanical model based on the delayed plasticity theory and calibrated on experimental results is proposed. The model is employed to evaluate the influence of geometry and forcing (air temperature) on a real rock glacier (Murtèl-Corvatsch rock glacier) creep behavior.

The impact of ground-ice thaw on landslide geomorphology and dynamics: two case studies in northern Iceland

As consequence of ongoing climate change, permafrost degradation is thought to be increasingly affecting slope stability in periglacial environments. This is of growing concern in Iceland, where in the last decade, permafrost degradation has been identified among the triggering factors of landslides. The role of ground ice in conditioning the morphology and dynamics of landslides involving loose deposits is poorly understood. We show the geomorphological impact of the Móafellshyrna and Árnesfjall landslides that recently occurred in ice-cemented talus deposits in northern Iceland. Using field and aerial remote-sensing measurements of the morphological and morphometric characteristics of the landslides, we assess the influence of thawing ground ice on their propagation style and dynamics. The two mass movements are complex and are similar to rock- and debris-ice avalanches, changing trajectory and exhibiting evidence of transitioning their style of motion from a dry granular mass to a debris flow-like movement via multiple pulses. We infer that the thawing of ground ice together with the entrainment of saturated material provided the extra fluid causing this change in dynamics. The hazardous consequences of permafrost degradation will increasingly affect mountain regions in the future, and ground-ice thaw in steep terrain is a particularly hazardous phenomenon, as it may induce unexpected long-runout failures and can cause slope instability to continue even after the landslide event. Our study expands our knowledge of how landslides develop in unstable ice-cemented deposits and will aid assessment and mitigation of the hazard that they pose in Iceland and other mountainous periglacial areas.

Increasing Spatio-Temporal Resolution for Monitoring Alpine Solifluction Using Terrestrial Laser Scanners and 3D Vector Fields

This article investigates the usage of terrestrial laser scanner (TLS) point clouds for monitoring the gradual movements of soil masses due to freeze–thaw activity and water saturation, commonly referred to as solifluction. Solifluction is a geomorphic process which is characteristic for hillslopes in (high-)mountain areas, primarily alpine periglacial areas and the arctic. The movement can reach millimetre-to-centimetre per year velocities, remaining well below the typical displacement mangitudes of other frequently monitored natural objects, such as landslides and glaciers. Hence, a better understanding of solifluction processes requires increased spatial and temporal resolution with relatively high measurement accuracy. To that end, we developed a workflow for TLS point cloud processing, providing a 3D vector field that can capture soil mass displacement due to solifluction with high fidelity. This is based on the common image-processing techniques of feature detection and tracking. The developed workflow is tested on a study area placed in Hohe Tauern range of the Austrian Alps with a prominent assemblage of solifluction lobes. The derived displacements were compared with the established geomonitoring approach with total station and signalized markers and point cloud deformation monitoring approaches. The comparison indicated that the achieved results were in the same accuracy range as the established methods, with an advantage of notably higher spatial resolution. This improvement allowed for new insights considering the solifluction processes.

Size-dependent chemical depletion of sediments in glacial environments: a case study of Mandakini Valley, central Himalaya, India

ABSTRACT The size-dependent chemical maturity of sediment cycling in a high-altitude glacial/periglacial environment was studied by examining the sediments of the Chorabari Glacier, Mandakini Valley, central Himalaya, India. Sediments evacuated from glacial debris and a periglacial area were studied via particle-size analysis, X-ray fluorescence, and X-ray diffraction of different grain-size fractions. The results suggest a clear control of grain-size fraction over chemical weathering and release of its attendant nutrients from the glacial substrate. Elemental indices suggest the release of nutrients is principally controlled through comminution and sub-glacial chemical weathering of leachable minerals such as feldspar, mica, and apatite. Owing to biogeochemical cycles, the release of nutrients like phosphorous and calcium is predominantly controlled through mineral dissolution process of aluminosilicate rocks containing apatite, carbonate minerals and organic complexes. Overall, the size-dependent chemical maturity of glacial sediments suggests a much more chemically active system than previously thought. This study is of particular importance for downstream weathering tracer studies of detrital sediments.

What and where are periglacial landscapes?

AbstractUncertainties about landscape evolution under cold, nonglacial conditions raise a question fundamental to periglacial geomorphology:what and where are periglacial landscapes?To answer this, with an emphasis on lowland periglacial areas, the present study distinguishes between characteristic and polygenetic periglacial landscapes, and considershow complete is the footprint of periglaciation?Using a conceptual framework of landscape sensitivity and change, the study applies four geological criteria (periglacial persistence, extraglacial regions, ice‐rich substrates, and aggradation of sediment and permafrost) through the last 3.5 million years of the late Cenozoic to identify permafrost regions in the Northern Hemisphere. In limited areas of unglaciated permafrost regions are characteristic periglacial landscapes whose morphology has been adjusted essentially to present (i.e., Holocene interglacial) process conditions, namely thermokarst landscapes, and mixed periglacial–alluvial and periglacial–deltaic landscapes. More widespread in past and present permafrost regions are polygenetic periglacial landscapes, which inherit ancient landsurfaces on which periglacial landforms are superimposed to varying degrees, presently or previously. Such landscapes comprise relict accumulation plains and aprons, frost‐susceptible and nonfrost‐susceptible terrains, cryopediments, and glacial–periglacial landscapes. Periglaciation can produce topographic fingerprints at mesospatial scales (103–105m): (1) relict accumulation plains and aprons form where long‐term sedimentation buried landsurfaces; and (2) plateaux with convexo–concave hillslopes and inset with valleys, formed by bedrock brecciation, mass wasting, and stream incision in frost‐susceptible terrain.

Modal sensitivity of rock glaciers to elastic changes from spectral seismic noise monitoring and modeling

Abstract. Among mountainous permafrost landforms, rock glaciers are mostly abundant in periglacial areas, as tongue-shaped heterogeneous bodies. Passive seismic monitoring systems have the potential to provide continuous recordings sensitive to hydro-mechanical parameters of the subsurface. Two active rock glaciers located in the Alps (Gugla, Switzerland, and Laurichard, France) have been instrumented with seismic networks. Here, we analyze the spectral content of ambient noise to study the modal sensitivity of rock glaciers, which is directly linked to the system's elastic properties. For both sites, we succeed in tracking and monitoring resonance frequencies of specific vibrating modes of the rock glaciers over several years. These frequencies show a seasonal pattern characterized by higher frequencies at the end of winters and lower frequencies in warm periods. We interpret these variations as the effect of the seasonal freeze–thawing cycle on elastic properties of the medium. To assess this assumption, we model both rock glaciers in summer, using seismic velocities constrained by active seismic acquisitions, while bedrock depth is constrained by ground-penetrating radar surveys. The variations in elastic properties occurring in winter due to freezing were taken into account thanks to a three-phase Biot–Gassmann poroelastic model, where the rock glacier is considered a mixture of a solid porous matrix and pores filled by water or ice. Assuming rock glaciers to be vibrating structures, we numerically compute the modal response of such mechanical models by a finite-element method. The resulting modeled resonance frequencies fit well the measured ones over seasons, reinforcing the validity of our poroelastic approach. This seismic monitoring allows then a better understanding of the location, intensity and timing of freeze–thawing cycles affecting rock glaciers.

ТЕМПЫ ДЕНУДАЦИИ В ПЕРИГЛЯЦИАЛЬНЫХ ОБЛАСТЯХ ВЫСОКОГОРИЙ: МЕТОДЫ И РЕЗУЛЬТАТЫ ИССЛЕДОВАНИЙ

Periglacial areas in the mountains are characterized by the highest denudation rates, which is due to active physical weathering, significant gradients and low projective vegetation coverage of the slopes of these areas. The accelerated expansion of periglacial areas that has taken place in recent decades is explained by climate changes that contribute to the melting of mountain glaciers. The improved methodology of studying the relief transformation processes, the rates of various exogenous processes, and the features of material redistribution along the pathways of sediment transportation from the slopes to the river valley bottoms contributed to a dramatic increase in quantitative assessment of spatio-temporal changes in the relief of the mountain periglacial zone. The article discusses various traditional and contemporary methods and approaches to studying the periglacial zone relief and its changes. They are divided into two groups: methods of stationary and semi-stationary observations of exogenous processes and methods for studying sediment redistribution in catchments. Various directions are highlighted within each group of methods, special attention is paid to the latest techniques. The results of observations of the rates of various exogenous processes occurring in the periglacial zone are generalized. It is shown that the intensity of rockfall-talus processes depends on lithology and frequency of daily air temperature fluctuation through zero °C and varies from 0.02 to 1.6 mm/year. Avalanche abrasion in avalanche trays reaches 40–70 mm/year. The rate depends on the area of the slope catchment, within which avalanches descend, and corresponds to the rate of denudation for the slope catchment equal to 0.01–0.05 mm/year. Maximum soil erosion rates are typical for young moraine slopes, where it reaches 100 mm/year in the first years after the glacier melts, and after 50 years slows down to 7–10 mm/year. The main flux of sediments is delivered from the slopes to the river bottoms by occasionally formed mudflows.

Viviendo en los Andes: registros notables de la distribución altitudinal del oso andino, Tremarctos ornatus (Ursidae) en Boyacá, Colombia

Living in the Andes: noteworthy records on the altitudinal distribution of the Andean bear Tremarctos ornatus (Ursidae) in Boyacá, Colombia Despite the importance of Andean bears, much relevant information regarding their distribution is lacking. Endemic to the Andes, the species is known to occupy the entire elevation gradient, but records to support this assumption are scarce. Here we present recent evidence of their presence in peri-glacial (> 4,000 m) and tropical forests (< 1.000 m) areas in the Eastern Andes of Colombia. Based on existing records and our own field work, we report 23 new records for marginal elevations, including the first records to be published for the Boyacá department. This information is valuable in order to increase our knowledge of Andean bear habitat use and distribution and thereby improve decision-making for the management of the species and its associated ecosystems. Data published through GBIF (Doi: 10.15470/32uicm) Key words: Elevation, Andean Range, Spectacled Bear, Boyacá

Long-term nivation rates, Cathedral Massif, northwestern British Columbia

Cryoplanation terraces (CTs) are large (3000–800 000 m2) erosional landforms found in upland periglacial environments. Two hypotheses for the formation of CTs are supported in contemporary literature: (1) CT formation is controlled primarily by geologic structure; and (2) CTs are climatically controlled through nivation, a suite of erosional processes associated with late-lying snowbanks. A persistent question in periglacial geomorphology is whether nivation can produce CT-scale landforms. This paper examines the unusual deglaciation history of “Frost Ridge” on the Cathedral Massif, northwestern British Columbia, to estimate long-term denudation attributable to nivation processes active since the last glacial maximum. Frost Ridge forms one flank of an east–west-oriented glacial valley. During deglaciation, marginal drainage created V-shaped erosional notches on both valley walls. Minimization of solar radiation on the steep north-facing wall (Frost Ridge) allowed snowbanks to accumulate and persist in the marginal drainage features and nivation processes to erode the slope. Today, several large nivation hollows (incipient CTs) are present near the summit of Frost Ridge, while the V-shaped marginal drainage features are preserved at lower elevations and on the opposite, south-facing valley wall. A high-resolution survey using an unmanned aerial vehicle (UAV) allowed volumes of marginal drainage and incipient terrace features to be compared. Based on this volumetric comparison, denudation rates are estimated to range from 4.2 to 125.8 mm/kyr, which are comparable with relatively short-term nivation rates reported from Antarctica and mid-latitude alpine periglacial areas.