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Glacial geomorphological mapping from the southern margin of Skálafellsjökull, southeast Iceland, depicts a topographically diverse mountainside, influencing glacier dynamics, landform formation and glacier retreat since the Little Ice Age maximum in ~1890. The glacial landforms present are typical of southeast Icelandic temperate glaciers, comprising recessional push moraines, including sawtooth moraines, and associated fluting. Study area A demonstrates an abandoned lobe confined by steep V-shaped topography, displaying moraines and minimal fluting, suggesting low preservation of landforms, and changes in glacier behaviour. At study area B, the sawtooth moraine morphology demonstrates changes in the glacier margin as the ice interacted with a series of topographic benches during active recession. The steep-sided valley at study area C illustrates densely spaced arcuate moraines, reflecting subtle changes in ice elevation. This mapping provides a framework for further investigations into glacier retreat rates and the influence of local topography and climate. [ABSTRACT FROM AUTHOR]

We present a 1:15,000 geomorphological map of the Maladeta massif in the Central Pyrenees. Our methodology includes fieldwork, the analysis of aerial photographs from 1956 to 2015, and the use of drone flights from 2020 to 2023. The study area consists mainly of granodiorite but also has outcrops of limestone, shales, and quartzites at lower elevations. The landscape of the Maladeta massif is primarily shaped by glacial and periglacial processes, with fluvial, karstic, and hillslope dynamics manifesting in the lower regions. The assessment of moraine thickness has facilitated the determination of maximum glacier thickness during the Little Ice Age (LIA) and has shown that there is no correlation between ice thickness and glacier extent. After the LIA, the massif experienced a continuous glacier retreat. Currently, only 21.4% of the glacier area observed in 1956 remains. [ABSTRACT FROM AUTHOR]

We review geochronological data relating to the timing and rate of Laurentide Ice Sheet recession in the northeastern United States and model ice margin movements in a Bayesian framework using compilations of previously published organic 14C (n = 133) and in situ cosmogenic 10Be (n = 95) ages. We compare the resulting method-specific chronologies with glacial varve records that serve as independent constraints on the pace of ice recession to: (1) construct a synthesis of deglacial chronology throughout the region; and (2) assess the accuracy of each chronometer for constraining the timing of deglaciation. Near the Last Glacial Maximum terminal moraine zone, 10Be and organic 14C ages disagree by thousands of years and limit determination of the initial recession to a date range of 24-20 ka. We infer that 10Be inherited from pre-glacial exposure adds 2-6 kyr to many exposure ages near the terminal moraines, whereas macrofossil 14C ages are typically 4-8 kyr too young due to a substantial lag between ice recession and sufficient organic material accumulation for dating in some basins. Age discrepancies between these chronometers decrease with distance from the terminal moraine, due to less 10Be inherited from prior exposure and a reduced lag between ice recession and organic material deposition. 14C and 10Be ages generally agree at locations more than 200 km distal from the terminal moraines and suggest a mostly continuous history of ice recession throughout the region from 18 to 13 ka with a variable pace best documented by varves. [ABSTRACT FROM AUTHOR]

The Jostedalsbreen is the largest ice cap in Norway and mainland Europe. Rapid retreat of many of its outlet glaciers since the 2000s has led to the formation of several glacial lakes. Processes causing the formation and expansion of glacial lakes and their interaction with a glacier and terminal moraine have not been widely addressed yet. In this study, we investigate the degradation of the front of the southeast‐facing outlet glacier Austerdalsbreen. Based on a variety of remotely sensed data (UAV‐based and airborne orthophotos and DEMs, satellite images), we analyze the coincident glacial and proglacial changes of Austerdalsbreen and quantify the evolution of this transition zone during the last decades. In particular, we focus on the short‐term evolution of the glacial lake since 2010, we examine the context of a glacier advance in the 1990s, and we report long‐term changes by utilizing 1960s imagery. We discuss the evolution and conditions of Austerdalsbreen compared to other outlet glaciers of Jostedalsbreen. Overall, the glacier terminus has experienced a recession in the last decades. The 1990s terminus advance was more restricted than at other nearby outlet glaciers due to glacier surface debris cover, which is a critical factor for the glacier and lake evolution. However, in the most recent period, since 2012, a distinct expansion of a glacial lake is quantifiable. Since the rates of glacier surface lowering also considerably increased since approximately 2017 and the glacier retreated since the beginning of the 2000s with a clear maximum length decrease in 2015, we interpret the recently formed glacial lake as a contributory factor of glacial changes. [ABSTRACT FROM AUTHOR]

Glacial retreat uncovers large bodies of unconsolidated sediment that are prone to erosion. However, our knowledge of overland flow (OF) generation and sediment transport on moraines that have recently become ice-free is still limited. To investigate how the surface characteristics of young moraines affect OF and sediment transport, we installed five bounded runoff plots on two moraines of different ages in a proglacial area of the Swiss Alps. On each plot we conducted three sprinkling experiments to determine OF characteristics (i.e., total OF and peak OF flow rate) and measured sediment transport (turbidity, sediment concentrations, and total sediment yield). To determine and visualize where sediment transport takes place, we used a fluorescent sand tracer with an afterglow as well as ultraviolet (UV) and light-emitting diode (LED) lamps and a high-resolution camera. The results highlight the ability of this field setup to detect sand movement, even for individual fluorescent sand particles (300–500 µm grain size), and to distinguish between the two main mechanisms of sediment transport: OF-driven erosion and splash erosion. The higher rock cover on the younger moraine resulted in longer sediment transport distances and a higher sediment yield. In contrast, the higher vegetation cover on the older moraine promoted infiltration and reduced the length of the sediment transport pathways. Thus, this study demonstrates the potential of the use of fluorescent sand with an afterglow to determine sediment transport pathways as well as the fact that these observations can help to improve our understanding of OF and sediment transport processes on complex natural hillslopes. [ABSTRACT FROM AUTHOR]

The results of integrated studies of the contents of natural radionuclides (NRNs) 226Ra, 232Th, and 40K and technogenic 137Cs in soils on moraine deposits available from the Bioresource Collection at the Dokuchaev Central Soil Museum are reported. Soils were sampled before the commencement of nuclear tests, during intensive tests, and in recent years. The assayed soils belong to 11 reference soil groups according to the WRB system. Organic, humus (including formerly plow), humus-eluvial, eluvial, and subeluvial horizons and soil-forming rocks were analyzed. The NRNs contents in soil-forming rock amount to 13.4–36.0 Bq/kg (mean specific activity M = 22.2 Bq/kg and standard deviation σ = 7.4 Bq/kg) for 226Ra; 18.9–49.0 Bq/kg (M = 32.1 ± 10.4 Bq/kg) for 232Th; and 417–890 Bq/kg (M = 695 ± 151 Bq/kg) for 40K. In the organic horizons, NRNs are detectable only in the samples of 2004 and 2017 in the amounts of 7.0–43.0 Bq/kg 226Ra (M = 20.9 ± 14.4 Bq/kg), 10.0–21.2 Bq/kg 232Th (M = 14.0 ± 8.1), and 50–620 Bq/kg 40K (M = 291 ± 227 Bq/kg). Narrower ranges and lower mean content (except for 40K) in the humus and eluvial horizons are recorded in the former plow horizon (P) as compared with the AY horizon and in the EL horizon as compared with the AEL and BEL horizons. The NRN content correlates with the particle size fractions in a statistically significant manner. Technogenic 137Cs is detectable only in the recent soil samples. According to its content, the soils fall into two groups. The first group of soils (pits 261 and MLK-4, Lisino education and experimental forestry station) displays a relatively high 137Cs activity in the 0–5-cm layer and a penetration depth of 10 cm. The second group comprises the remaining soils. The cesium content there does not exceed 54 Bq/kg and penetration depth, 20 cm. [ABSTRACT FROM AUTHOR]

Buried mounds have been identified on seismic reflection profiles in the southern Roosevelt sub-basin of the eastern Ross Sea, Antarctica. Since they have never been sampled, the composition of these mounds can only be inferred from their acoustic character. Previous studies have hypothesised that they are buried glacial moraines deposited by ice grounding near the paleo-continental shelf edge, suggesting the beginning of the growth of the West Antarctic Ice Sheet (WAIS) as early as the late Oligocene. This hypothesis conflicts with earlier evidence of the WAIS advance over the central-eastern Ross Sea. An alternative explanation for the origin of the mounds, as mud volcanoes, is formulated here on the basis of seismic reflection profile reprocessing and comparison with other, better studied, mound provinces in the Ross Sea. Shallow drilling is required to verify, which hypothesis is correct, and this has implications for various WAIS scenarios, ice volumes, and thermal rheological modelling. [ABSTRACT FROM AUTHOR]

Generalization of the grain size analyses of the basal Neopleistocene moraines from the sections of coastal outcrops and boreholes in the vast European Subarctic region of Russia and in more southern areas of the Timan–Pechora–Vychegda region showed that the moraines are typical mixed, almost unsorted rocks with similar contents of the gravel–sand, silt, and clay fractions, serving as one of the arguments in favor of their glacial genesis. Their grain size composition is related to the peculiarities of rocks in the glacier bed. It is formed during the crushing, abrasion, and mixing of the glacier-rafted, assimilated, and transported material during its transportation and deposition, which determines variability of the grain size composition of moraines. Consequently, the grain size composition of moraines in combination with other lithological data reflects the pathway and dynamics of the glacier movement. [ABSTRACT FROM AUTHOR]

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A warming environment is promoting the thawing process in ice‐rich moraine soils in cold alpine regions, thereby accelerating the formation/development of geohazards in these regions. The mechanism of these geohazards is closely related to the thermal‐hydraulic (TH) coupling behavior of moraine soils, which has rarely been investigated. Here, we conducted a series of bench‐scale TH coupling simulations of moraine soils with ice inclusions in a warming environment. The numerical model was conceptualized from a field survey on the Qinghai‐Tibet Plateau, which consists of a porous medium embedded with multilayer ice cubes with warmer water continuously flowing through it. A TH coupling framework considering ice‐water phase change was established to implement this coupled simulation with different initial ice contents and hydraulic gradients. The simulated results showed phased and nonlinear evolutionary features of temperature, ice content, and permeability for the moraine soil system. Further analyses showed that these complex evolutionary features can be reproduced by empirical formulas, with concise expressions following dimensional consistency and some coefficients having potential physical meanings. The discriminant models of two equilibrium states were finally developed to predict the critical times of structure stabilization and thermal equilibrium of the moraine soil system. This study presents the complex evolution of TH coupling properties of moraine soils, and simultaneously demonstrates that these properties can be predicted and characterized. Plain Language Summary: Due to large‐scale and multistage glacier evolution, substantial moraine soils have accumulated in cold alpine regions. These moraine soils include abundant buried ice in various configurations formed during glacial evolution, and the thawing of this buried ice is accelerating the development of geohazards in these regions. The initiation and evolution of these geohazards are largely controlled by heat transport and groundwater flow induced by ice‐water phase change in moraine soils, but these coupling processes are poorly understood and poorly characterized. Here, we numerically investigated the thermal‐hydraulic (TH) coupling behaviors of moraine soils with ice inclusions in a warming environment. The simulated results revealed phased and nonlinear evolutionary features of the moraine soil system, with respect to heat transport, pore structure, and hydraulic conductivity. We demonstrated that these complex evolutionary features can be well characterized by empirical formulas, and their equilibrium states can be predicted based on the initial ice content and applied hydraulic gradient. These findings and results deepen our understanding of TH coupling behavior for moraine soils with ice inclusions, and serve as a basis for characterizing evolutionary processes of geohazards related to moraine soils in cold alpine regions under climate warming. Key Points: Fully coupled thermal‐hydraulic simulations considering phase change were conducted for moraine soils with separate ice inclusionsEvolution of heat transport, ice content, and hydraulic conductivity of moraine soil was quantitatively characterizedEquilibrium‐state discrimination models were developed to predict structure stabilization and thermal equilibrium of the moraine soil system [ABSTRACT FROM AUTHOR]

Spatial distributions of drumlin fields encode information about ice sheet dynamics. No drumlins formed beneath the most lobate parts of the Laurentide Ice Sheet's southern margin, in South Dakota, Iowa and Illinois, whereas ice lobes to the northeast generally produced drumlins. This pattern may have resulted from northerly ice overriding permafrost. Here we propose a new hypothesis for this pattern by constructing a LiDAR‐based landform map and applying a model of drumlin formation to account for the absence of drumlins beneath the largest of the ice sheet's southern lobes, the Des Moines Lobe. Broad belts of hummocky topography, ice‐walled lake plains, doughnuts and minor moraines, which together cover 90% of the lobe's upland area in Iowa, attest to widespread ice stagnation, as does the lobe's scarcity of eskers. Most stagnation topography is subtle, with insufficient relief to have obscured drumlins that might have formed before stagnation. Minor moraines are crevasse‐squeeze ridges diagnostic of surging, and their ubiquity indicates that during surging, the lobe's soft bed was weak nearly everywhere. End moraines are generally parallel to a minor moraine setup‐glacier, implying that surge‐driven advances were more numerous than indicated by the three major end moraines of the lobe. In the only physically based model of drumlin formation that includes surging, till deposition occurs during surges when effective pressure is uniformly low, whereas drumlins develop during quiescent flow between surges, when basal slip and low‐pressure R‐channels create the spatial gradients in effective pressure necessary to sculpt drumlins by differential erosion. Landforms of the lobe, however, indicate stagnation and down‐wasting during quiescence, without significant basal slip or hydraulic potential gradients necessary for R‐channels. We hypothesize that for the three southernmost lobes of the Laurentide Ice Sheet, surging followed by widespread down‐wasting of stagnant ice prevented drumlin formation, whereas beneath northern lobes it was permitted by climatically‐forced ice advance. [ABSTRACT FROM AUTHOR]

Modern permafrost conditions of the Subpolar Urals are characterized by the example of peat bogs of the lateral moraine in the vicinity of Narodnaya mountain area (Polar Urals, Russia). Changes in permafrost conditions due to warming, studied by georadar survey and radiocarbon dating. The depth of thawing in these bogs was also determined by measuring the depth of the seasonally thawed layer and the temperature of the rocks using a thermometer and a metal probe 1.5 m long along a 100 m profile with a step of 10 m. It was found that the depth of the STL ranged from 10 to 140 cm at a permafrost surface temperature of 0 °C. The structure of the peat deposit was checked on a dry section of the swamp using a pit 40 cm deep. It was found that the peat bog is underlain by frozen clay-loam. In the peatland itself, several boundaries of peat and gley accumulation are visible in the layers directly above the underlying loam, which indicates a repeated change in the conditions of peat accumulation at the beginning of warming or the movement of rocks as a result of solifluction flows from nearby slopes. [ABSTRACT FROM AUTHOR]

Machine learning is a powerful yet underutilised tool in geomorphology, commonly used for image–based pattern recognition. Analysing new high–resolution (1–10 m) elevation datasets, we investigate its usefulness for detecting discrete geomorphological features. This study develops a machine learning–based method for identifying ribbed moraines in digital elevation data and progresses to test its performance versus time consuming, manual methods. Ribbed moraines share geomorphometric characteristics with other glacial landforms, hence represent a valuable test of our new methodology in terms of differentiating between similar features, and wider for detection of landforms with similar characteristics. Furthermore, mapping ribbed moraines may provide valuable indications of their origin, a topic of debate within glacial geomorphology. To automatically detect ribbed moraines, we extract simple morphometrics from high–resolution digital elevation model data and mask regions where ribbed moraines are unlikely to form. We then test several machine learning algorithms before examining the best performer (K–means clustering) on three study areas in Norway of 15 km2. Our results demonstrate balanced accuracy of 65–75 % when validating versus ground–truth. The performance depends on the availability of high–resolution elevation data in Norway, needed to resolve the spatial scale of the target (10–100 m). We find the method effective at detecting both fields of ribbed moraines as well as individual ribbed moraines. We propose pathways for future implementation of this method on a large–scale and for increasing the detail of information gained about detected landforms. In conclusion, we demonstrate K–means clustering as a promising method for detecting ribbed moraines, with great potential to reduce the time needed to produce landform maps. [ABSTRACT FROM AUTHOR]

Under the effect of global warming, the Sedongpu Basin, located in the lower reaches of the Yarlung Zangbo River on the Tibetan Plateau, has experienced frequent ice and rock avalanche disasters, which were particularly prominent after the 2017 Ms6.9 Milin earthquake, resulting in significant topographic geomorphological changes. The current geomorphology of the Sedongpu Basin, as well as the moraine volume and geomorphological changes since 2017, was interpreted in detail by unmanned aerial vehicle (UAV) and InSAR technology. Sedongpu Basin can be divided into the ice and rock area and moraine area and dam area according to the material and disaster characteristics. There are large structural planes and wide cracks in the ice and rock area, which provide the material basis for ice and rock avalanches. Moraines in the moraine area are widely distributed and very thick; the maximum change in moraine height since 2017 reaches 335 m; the moraine volume has decreased by more than 420 million m3, and strong erosion and geomorphic changes have occurred. The dam in the dam area has a thickness of ~ 37–40 m, and now, the residual dam area is 9.2 km long, with an impact area of more than 8.1 km. The InSAR interpretation shows two large deformation areas; the maximum cumulative deformation reaches 130.7 m, and there is still a possibility of disaster in the future. In addition, it is discussed that the different material properties of different areas make the Sedongpu Basin show obvious vertical zonation characteristics, resulting in disaster chain effects. Such effects not only play a role in modifying the geomorphology of the Sedongpu Basin and the Yarlung Zangbo River channel but also amplify the ice and rock avalanche disasters in the alpine area. [ABSTRACT FROM AUTHOR]

Rockwall erosion in high-alpine glacial environments varies both temporally and spatially. Where rockwalls flank glaciers, changes in debris supply and supraglacial cover will modify ice ablation. Yet, quantifying spatiotemporal patterns in erosion across deglaciating rockwalls is not trivial. At five nearby valley glaciers around Pigne d'Arolla in Switzerland, we derived apparent rockwall erosion rates using 10 Be cosmogenic nuclide concentrations ([ 10 Be]) in medial moraine debris. Systematic downglacier sampling of six medial moraines that receive debris from rockwalls with differing orientation, slope, and deglaciation histories enabled us to assess rockwall erosion through time and to investigate how distinct spatial source rockwall morphology may express itself in medial moraine [ 10 Be] records. Our dataset combines 24 new samples from medial moraines of Glacier du Brenay, Glacier de Cheilon, Glacier de Pièce, and Glacier de Tsijiore Nouve with 15 published samples from Glacier d'Otemma. For each sample, we simulated the glacial debris transport using a simple debris particle trajectory model to approximate the time of debris erosion and to correct the measured [ 10 Be] for post-depositional 10 Be accumulation. Our derived apparent rockwall erosion rates range between ∼ 0.6 and 10.0 mm yr -1. Whereas the longest downglacier [ 10 Be] record presumably reaches back to the end of the Little Ice Age and suggests a systematic increase in rockwall erosion rates over the last ∼ 200 years, the shorter records only cover the last ∼ 100 years from the recent deglaciation period and indicate temporally more stable erosion rates. For the estimated time of debris erosion, ice cover changes across most source rockwalls were small, suggesting that our records are largely unaffected by the contribution of recently deglaciated bedrock of possibly different [ 10 Be], but admixture of subglacially derived debris cannot be excluded at every site. Comparing our sites suggests that apparent rockwall erosion rates are higher where rockwalls are steep and north-facing, indicating a potential slope and temperature control on rockwall erosion around Pigne d'Arolla. [ABSTRACT FROM AUTHOR]

Proglacial areas are dynamic landscapes and important indicators of geomorphic changes related to climate warming. Systematic and repeat surveys of landforms presently evolving on glacier forelands facilitate the quantification of rates of change and an improved understanding of the processes generating those changes. We report short‐term (2014–2022) transformations of the proglacial landscape in front of Kvíárjökull, SE Iceland, and place them in a longer‐term context of glacial landsystem evolution using aerial image archives since 1945. Short‐term quantification uses a time series of uncrewed aerial vehicle (UAV) surveys, processed utilizing a structure‐from‐motion (SfM) workflow, to produce digital elevation models (DEMs) and orthophoto mosaics. The land elements surveyed include a kame terrace staircase, an outwash plain, an ice‐cored hummocky moraine complex and ice‐cored hummocky terrain with discontinuous sinuous ridges, for which elevation and volumetric changes are quantified. The kame terraces between 2014 and 2022 and the outwash plain between 2016 and 2022 were mainly stable with, respectively, 87% and 85% of their surfaces showing no change. The ice‐cored hummocky terrain with discontinuous sinuous ridges underwent a volume loss of 64,632 m3 in 2016–2022, with a maximum surface lowering of ≤9 m. The most dynamic land element was the ice‐cored hummocky moraine complex, with transformations recorded for more than 87% of its area in 2014–2022; the surface was lowered by ≤23 m in some places, with a total volume loss of 365,773 m3. Our results confirm the ongoing degradation of ice‐cored moraine and outwash complexes at variable rates related to buried ice volume and age of deglaciation. The evolution of chaotic hummocky terrain from debris‐covered glacier ice, glacitectonic thrust masses, outwash fans/heads and complex englacial esker networks is an important modern analogue for informing palaeoglaciological reconstructions. [ABSTRACT FROM AUTHOR]

Terrestrial cosmogenic nuclide (TCN) dating has emerged as one of the most useful techniques in the last two decades for quantifying geomorphological processes and building the chronology of late Quaternary glacial advances/retreats. The chronology based on TCN and optically stimulated luminescence (OSL) dating of glacial landforms from the northwestern (NW) Himalaya suggests that glaciers responded to a complex interaction between temperature and moisture essentially derived from either of the climate systems, the Indian Summer Monsoon (ISM) and the Mid‐latitude Westerlies (MLW). The discrepancies between the TCN ages obtained on moraine boulders/bedrock surfaces, and the OSL ages on the stratigraphically equivalent deposits, highlighted the need for a detailed investigation. The present study attempts to build the chronology of Quaternary glaciation events in the Karakoram and Ladakh Ranges using TCN dating of stratigraphically constrained moraine boulders and striated bedrock surfaces. The TCN ages from glacially eroded surfaces (GES) having prominent striations are narrowly clustered around the Marine Isotopic Stage‐2 (MIS‐2). Agreement between GES TCN ages and OSL ages on the stratigraphically equivalent moraines suggests negligible geological inheritance. The glacial advance during MIS‐2 can be attributed to the combined effect of reduction in north hemispheric insolation and enhanced westerly precipitation. However, relict non‐glacial surfaces and moraine boulders with minimal ice flow modifications yield wide age distributions, most likely suggesting denudational events (interglacials) and/or contribution from tributary valley flanks. Plain Language Summary: Quaternary glacial advances and retreats in the northwestern (NW) Himalaya respond to a complex interaction between climatic parameters, that is, temperature and moisture essentially derived from the two contrasting weather systems viz., the Indian Summer Monsoon (ISM) and the Mid‐latitude Westerlies (MLW). In this study, we employed terrestrial cosmogenic nuclide dating of stratigraphically constrained moraine boulders and striated bedrock surfaces to understand the dynamics of late Quaternary glaciation in the Karakoram and Ladakh ranges. The exposure ages obtained from glacially eroded surfaces (GES) show a narrow cluster around the Marine Isotopic Stage‐2 (MIS‐2), a period when the northern hemispheric insolation was low resulting in a temperature decline. The glacial advance during MIS‐2 is attributed to the combined effect of temperature reduction and enhanced westerly precipitation. Key Points: New insight into the Quaternary glacial history of NW Himalaya based on 40 10Be exposure ages of boulders and bedrock surfacesGlacially eroded surface ages suggest that Marine Isotopic Stage‐2 glacier advances were driven by enhanced westerlies and reduced insolationRelict non‐glacial surface/boulder ages indicate denudational events during the interstadial and/or contribution from tributary valleys [ABSTRACT FROM AUTHOR]

The correction notice in the journal Hydrobiologia addresses an error in the publication comparing long-term changes in cladoceran and diatom assemblages in a lake affected by road salt seepage to a nearby reference lake near Toronto, Ontario, Canada. The correction involves a duplicate version of Fig. 5 being mistakenly used as Fig. 1, which has now been rectified. The corrected article by R. E. Valleau, K. G. Murray, A. M. Paterson, and J. P. Smol can be accessed online for accurate information on the study. [Extracted from the article]

The geological environment of Pulang copper mine is fragile, and collapse pits will be formed on the surface during mining. When continuous rainfall occurred, the surface moraine is saturated in water absorption and flows into the mine outlet, causing debris flow disaster in the underground. In response to this problem, experiments on the influencing factors and influencing rules about the gelling time of sodium silicate-curing agent slurry and the strength of moraine soil consolidation are carried out. The experimental results show that the slurry gels faster as the concentration of the catalyst increases in the mixture of sodium silicate-curing agent. The gelation time of sodium silicate-curing agent slurry decreases first and then increases with the concentration of curing agent increasing. Meanwhile, with the increase of sodium silicate s concentration it will spend less time for sodium silicate-curing agent slurry gelling. In addition, both the concentration of sodium silicate and the concentration of curing agent have a positive effect on the compressive strength of the moraine consolidation body. The experimental results can provide a theoretical basis for the grouting solidification of surface moraine. [ABSTRACT FROM AUTHOR]

The Hengduan Mountains is in the transitional zone between the Qinghai-Tibet Plateau (QTP) and the Yunnan-Guizhou Plateau in China, and a key area for elucidating the Quaternary environmental changes in Asia. The paleo-Daocheng ice cap was located on the Shaluli Hilly Plateau in the northeastern Hengduan Mountains, the oldest moraines in the Hengduan Mountains region were found in the ice cap area. Such glacial landforms provide key evidence to study the timing when this area entered the cryosphere with the uplift of the QTP. However, it is difficult to collect suitable glacial boulders from these moraines for traditional terrestrial in-situ cosmogenic nuclide (TCN) exposure dating because of long-term severe moraine degradation. Here, we collected clast samples from the moraine surface and depth profile to constrain the age of the oldest moraine in Kuzhaori (moraine E) using TCN 10Be dating technique. The minimum 10Be ages of five clast samples from the moraine surface range from 187.4±1.5 to 576.8±4.3 ka, implying that the moraine has been seriously degraded since deposition. Based on the TCN 10Be concentrations of the samples from a depth profile and simulations, the exposure-erosion-inheritance history of the profile was obtained. By fitting to the profile 10Be concentrations using the chi-square test, the simulations yielded a reliable age of 626.0±52.5 ka for the moraine. Therefore, the oldest moraine (moraine E) in Kuzhaori was most likely formed at about 0.63 Ma ago, corresponding to the marine isotope stage (MIS) 16. This glaciation represents the maximum Quaternary glaciation after the QTP was elevated into the cryosphere by the Kunlun-Yellow River Tectonic Movement. [ABSTRACT FROM AUTHOR]

Within Alpine catchments, glacial landforms are subject to post-depositional reworking during and following deglaciation. Ice-marginal moraines are thought to rapidly stabilise within ~200 years in this topographic context, although ice-proximal slopes are particularly prone to alteration by debris flows and solifluction. This study investigates landform transformation, documenting geomorphological change at the Bas Glacier d'Arolla, Switzerland. Gully development on a moraine slope was assessed using archive image sets obtained in 1977, 1988 and 2009 to derive historical elevation models. Raster differencing suggests that the mean rate of surface lowering on the upper moraine slope was 7.15 ± 1.83 m (± minimum level of detection) over the observation period (1977–2009), a rate of 0.22 m yr−1. The erosion of the landform resulted in an incontiguous moraine crestline. Whilst some landforms may undergo limited transformation upon deglaciation, selected sites are subject to rapid geomorphologic change, involving crestline retreat via the initial dissection by gullies, followed by the removal of inter-gully slopes. [ABSTRACT FROM AUTHOR]

The Laurentide Ice Sheet (LIS) was the largest ice sheet in the Northern Hemisphere during the last glacial cycle. The effects of its demise on global climate and sea‐level changes during the subsequent deglaciation are unequivocal. Understanding the interplay between ice sheets and long‐term or short‐term (e.g. abrupt) climatic events is therefore crucial for predicting future rates of ice sheet melting and their potential contribution to sea‐level changes. Here, we present 37 new 10Be surface exposure ages from easternmost Québec–Labrador that allow us to identify close ties between regional deglaciation history and climate. These results reveal that the LIS was disconnected from the Newfoundland Ice Cap by ~14.1 ka. Samples collected from moraine boulders indicate that this event was followed by five major stillstands and/or readvance stages of the LIS margin. Integrating our new moraine ages with those of earlier studies allows us to depict a temporal framework including events at ~12.9, ~11.5, ~10.4, ~9.3 and ~8.4–8.2 ka. These moraine ages highlight a strong sensitivity of the LIS to temperature changes in the Northern Hemisphere, as the documented continental ice margin stabilizations coincide with abrupt cooling events recorded in Greenland ice cores. These observations support the idea of a negative feedback mechanism induced by meltwater forcings into the North Atlantic Ocean which, in turn, provoked repeated cold reversals during the Younger Dryas and early Holocene. [ABSTRACT FROM AUTHOR]

Extending the record of glacier area changes into the past improves our understanding of climate change impacts. Although analogue maps showing historic glacier extents are abundant, digital outlines from before the satellite era are sparse as the digitisation of moraines and trimlines on freely available satellite images is challenging. With the now available very high-resolution images provided by Web Map Services (WMS), new doors are open for the precise digitisation. Here, we used the ESRI WMS to digitise Little Ice Age (LIA) glacier extents and present area changes since the LIA in four selected regions along with a detailed uncertainty analysis. We used modern glacier outlines as a starting point and additionally consulted Sentinel-2 images, the ArcticDEM and historic maps for interpretation. Dating records from the literature allowed calculating area change rates. In total, 493 LIA glaciers (4640 km2, now 891 ice bodies with 3590 km2) were digitised, yielding relative area changes of −20% (−0.14% a−1), −15% (−0.10% a−1), −26% (−0.16% a−1) and −61% (−0.19% a−1) for Alaska, Baffin Island, Novaya Zemlya and the tropics, respectively. The ESRI WMS images are a great asset to precisely map moraines and trimlines, but information about the timing of the related extents requires further sources. [ABSTRACT FROM AUTHOR]

Here we present geomorphological evidence of a previously unrecognised ∼50 km long, ice-marginal moraine complex in southwestern Skåne, southernmost Sweden, which we name the "Lund Moraine". This lobate moraine marks a sharp boundary between heavily streamlined and gently undulating landscapes, and closely outlines the extent of the "Lund till/diamicton". We interpret that the moraine was formed by a northward readvance, corresponding to a last Young Baltic readvance of the Scandinavian Ice Sheet into Öresund. Consequently, we infer that the "Lund till/diamicton" was formed subglacially, in contrast to earlier interpretations of it being a waterlain diamicton. Based on previously published dates, stratigraphically below "Lund till/diamicton", we infer that this readvance occurred sometime after c. 16 cal. ka BP. This readvance could offer an explanation to the apparent discrepancy of observations of the postglacial marine limit from outside and inside the Lund Moraine. Our observations will hopefully settle the ∼50 years long controversy concerning the extent or even existence of such a readvance into Öresund. We expect that our findings will guide further work towards disentangling the complex deglacial history of Skåne and the wider Öresund region. [ABSTRACT FROM AUTHOR]

Primary succession and microtopography result in environmental changes and are important processes influencing the community assembly of soil fungi in the Arctic region. In glacier forefields that contain a series of moraine ridges, both processes contribute synchronously to fungal spatial diversity. To reveal the synergistic effects of succession and microtopography, we investigated the fungal community structure and environmental variables in the moraines of the Arklio Glacier, Ellesmere Island. The study sites were established at four locations from the top to the bottom of the ridge slope within each of the three moraine ridges of different post-glacial ages. The location-dependent community composition was equally diverse in both the initial and later stages of succession, suggesting that successional time could alter the effects of microtopography on the fungal community. Moreover, our results suggest that fungal communities at different locations follow different successional trajectories, even if they have passed through the same time lapse. Such a synergistic effect of succession and microtopography of moraines does not allow for parallel changes in fungal communities among moraines or among locations, suggesting that the moraine series contributes substantially to fungal spatial diversity in the glacier forefield. [ABSTRACT FROM AUTHOR]

The compression and creep characteristics of moraine soil are important mechanical properties of geomaterials to be analyzed during the construction process of engineering projects. However, related references about these characteristics through large-size in-situ tests have rarely been reported. In this study, in-situ tests of particle size distribution, compression deformation, and compression creep were conducted at the Xingkang Bridge, West Sichuan, China. The results show that the uniformity coefficient of moraine soil ranges from 12.1 to 183.3, and gradation coefficient ranges from 0.4 to 2.8. The total compression deformations of moraine samples during the conventional compression deformation test are 4.70, 4.07, and 0.47 mm, and their residual deformations are 2.81, 2.45, and 0.22 mm, respectively. The deformation modulus ranges from 127.3 to 676.4 MPa, and elastic modulus ranges from 316.3 to 765.7 MPa. During compression creep tests, moraine soil enters the steady creep stage after 3.8 h of loading pressure at 445 kPa, and it keeps steady after 14 h of loading pressure at 900 kPa. The Burgers model and generalized Kelvin model predict the deformation well in transient, deceleration and steady creep stages. Results provide a valuable reference for the analysis of the compression deformation and creep behavior of moraine soil during engineering construction and management. [ABSTRACT FROM AUTHOR]

This article explores the ideas and processes of an 'excavatory' poetics and its interrelation with archaeological fieldwork, archives and exhibitions. I first focus on notions of authorial intent in the collage poetics of Susan Howe, suggesting that her interrogation of archives has an excavatory quality which reveals a concern with the articulation of provenance. I argue that Howe's work repositions the reader at the site of artefactual discovery, before the object has been sanitised, removed from its context, and provided with an authoritative interpretation. The article then documents my own work, The Cult Revived, which, by drawing on Joseph Campbell's image of a 'moraine of myths', assembles a 'word moraine' from which a series of poetic excavations are made. I argue that, despite there being no 'great lost form' to reconstitute, meaning-making can arise through the archaeological methodology of arranging textual shards on the museum table of the page. Despite the provisional status of such 'findings', I suggest that The Cult Revived reflects the broader instabilities and uncertainties inherent in archaeological endeavour, when set against the inscrutable and intractable agencies of deep time. [ABSTRACT FROM AUTHOR]

Characterising the structures within glaciers can give unique insight into ice motion processes. On debris-covered glaciers, traditional structural glaciological mapping is challenging because the lower glacier is hidden by the supraglacial debris layer. Here, we use high-resolution optical televiewer (OPTV) image logs from four boreholes drilled into Khumbu Glacier, Nepal, to overcome this limitation and investigate englacial structural features within a Himalayan debris-covered glacier. The OPTV logs show structural features that are up to an order of magnitude thinner than those observed at the glacier surface and reveal five structural units: (I) primary stratification of ice; (II) debris-rich planes that conform with the primary stratification; (III) water-healed crevasse traces; (IV) healed crevasse traces; and (V) steeply dipping planes of basally derived fine sediment near the glacier terminus. The OPTV logs also reveal that the primary stratification both decreases in dip with depth (by up to 56° over 20 m) and rotates with depth (by up to 100° over 20 m) towards parallelism with the proximal lateral moraine. This transformation and the presence of relict layers of basally derived sediment raised into an englacial position – possibly involving thrusting – near the glacier's now stagnant terminus reveal a previously more dynamic glacier regime. [ABSTRACT FROM AUTHOR]

High‐quality subsurface data provide new insights into the formation of Oak Ridges Moraine (ORM), an ~80 km3 sequence of stratified meltwater deposits resting >200 m above adjacent Lake Ontario. The ORM sedimentary succession comprises a three‐part regional architecture: (i) ~north–south channel sand–gravel; (ii) channel‐capping rhythmites; and (iii) east–west ridge sediments. The ORM depositional sequence overlies a regional unconformity with a cross‐cutting channel network resulting from ~north–south meltwater floods that transitioned progressively (falling stage) from a ~NNE to ENE flow direction (parallels Lake Ontario depression). Seismic profiles delineate the channels and channel fill characteristics of bank‐to‐bank channel sedimentation of thick gradational gravel–sand–mud sequences. Channel‐capping mud (~100–236 rhythmites) within multiple channels beneath the ORM landform mark a widespread interval of low‐energy, seasonally controlled subglacial pond deposition. During this quiescent period ice‐sheet thickness adjusted to flood‐induced stretching/thinning and re‐profiled slopes. New ice gradients led to east–west flow and deposition of the overlying third element, a sequence of high‐energy confined esker–fan sediments along ORM ridge. Close, sequential timing (~329 varve years) of channel, basin and ridge‐forming architectural elements supports naming this assemblage the ORM formation. Proposed ORM floods are analogous to Icelandic jökulhlaups based on the size, geometry and sedimentology. The observed rhythmite interval between flood events represents a short period (~236 years) of regional meltwater storage prior to east–west ORM flooding. The ORM channel and overlying esker‐fan sediment ridge represent two closely timed meltwater drainage events rather than formation by coalescing ice streams. The scale and timing of the ORM flood events are linked to rapid sea‐level rise, ~13.5 ka BP. This high‐resolution ORM sedimentological record may provide insights into depositional and glaciogenic controls of other large, stratified moraines. The ORM data indicate deposition in response to hydrodynamic events (outbreak floods, re‐profiled ice) rather than direct climate forcing. [ABSTRACT FROM AUTHOR]

Peña Ubiña Massif is one of the highest mountain areas in the Cantabrian Mountains (El Fontán sur, 2417 meters a.s.l.). Due to its vertical orography, it retains the moisture carried by the winds, causing abundant fog and rainfall that exceeds 2000 mm on its summits, many of which are in the form of snow. Karstic, fluviotorrential, glacial, periglacial and gravitational processes and landforms have been identified (relict in some cases and active in others). The action of the karst led to the development of erosive landforms such as dolines, nivokarstic sinkholes, chasms and a great diversity of karren. On the other hand, Peña Ubiña Massif presents a well-developed glacial landscape composed by erosive landforms such as glacial troughs, roches moutonnées and glaciokarst depressions (the latter of mixed genesis, karstic first and glacial later); as well as accumulation landforms, especially several generations of lateral, frontal and basal moraines, which allowed the identification of three main glacial stages (Maximum Ice Expansion Stage or MEH; Internal Stage I and II and Altitude Stage I and II), with 20 glaciers which occupied an extension of 5004 hectares during the MEH Stage. For its part, the present-day thermal regime is characterized by an abundance of frosts, but by a reduced number of freeze-thaw days on the soil. These cold conditions favour the development of cryoturbation, frost shattering, solifluction, rapid mass movements such as debris flows and snow avalanches, and an abundance of snow, which tends to remain between 6-8 months above 1800 meters a.s.l. [ABSTRACT FROM AUTHOR]

A comprehensive study of the glacial relief structure and morphology has been carried out for the first time in the Gorodok Upland (northeastern Belarus). New data have been obtained using lithological–stratigraphic, petrographic, and morphometric methods. The upland formation was caused by uplifting at the top of the Upper Devonian rocks. This pre-Quaternary surface uplift was overbuilt by Middle Pleistocene glacial deposits with glaciodislocations and erratic masses. As a result, the upland was formed in the ice-divide zone between the Chud and Ladoga ice streams during the last glaciation. Under the maximum advance of the last ice sheet, a moraine plateau with kames began to be formed in the center of the upland. At the Lepel Stage (18–20 cal. ka BP, Edrovo in Russia, Gruda in Lithuania, and Poznan in Poland), the ice lobes of the Chud and Ladoga ice streams moved from the periphery to the moraine plateau. In total, there were six distinct oscillations of the glacial edge. As a result, chains of hummocky and ridge end-moraine landforms were formed. Later, at the Braslav Stage (16–18 cal. ka BP, Vepsa in Russia, Baltija in Lithuania, and Pomeranian in Poland), hummocky end-moraine landforms appeared on northwestern and northeastern slopes of the upland. At the same time, the ice melting process resulted in large runoff troughs crossing the upland from north to south. The study results are important for reasonable geological survey and prospecting for mineral building materials within the ice-divide zones of the last glaciation. [ABSTRACT FROM AUTHOR]

Three moraines of different ages and morphology were identified in the valley of the Ev'vayam River on the basis of the interpretation of satellite images and field observations. The oldest, poorly preserved and significantly eroded, moraines are located in the lower reaches of the Ev'vayam River near the Bering Sea coast. A complex of the younger moraines consisting of three moraine ridges (45, 62–72, and 87–95 m a.s.l.) with thin soil cover are well manifested in relief. They were distinguished in the middle reaches of the Ev'vayam River. The youngest moraines are revealed in the upper reaches of the Ev'vayam River valley at elevations of 240–320 m a.s.l., where they form longitudinal ridges, or "tongues." The degree of preservation, morphology, and size of the studied glacial complex and the published data on adjacent areas point to a mountain–valley type of glaciation of the area. The glacier apparently reached its maximum size at the beginning of the Late Pleistocene, when it moved beyond the Ev'vayam valley to the coast. Moraines in the central part of the valley and in its upper reaches were formed by much smaller glaciers during the end of the Late Pleistocene. The recharge area of glaciers during this period was limited to a series of glacial cirques and corriers in the central part of Pylgin Ridge. Currently, small glaciers are present in cirques at elevations from 410 m to 720 m a.s.l. and they continue to form modern moraines. [ABSTRACT FROM AUTHOR]

Recent anthropogenic climate change has caused both glacial retreat and increased vegetative growth on Arctic and subarctic tundra landscapes resulting in changing albedo and energy budgets. Glacial forelands are topographically and ecologically heterogeneous landscapes comprising ice-contact and outwash deposits subject to primary succession. The most recent moraines on the foreland of the Skaftafellsjökull in southern Iceland are mostly unvegetated, but vegetation cover increases with the age in a general sense. Vegetated outwash channel terraces occur between the moraines, and a broad vegetated outwash plain occurs distal to the oldest moraine. Variations in albedo were measured at ground level to determine the specific role of vegetation types and varying substrates. Albedo and coverage by major plant groups were measured along transects established on moraines ranging in age from 20 to 130 years and the terrace of one outwash channel and three locations on the outwash plain. Total vegetation cover and coverage by mosses increases on the glacial moraines largely as a function of time but is subject to strong aspect effects. Total vegetation cover and moss cover are highest on outwash deposits, possibly due to a sheltered aspect and greater uniformity of the outwash surface. Measured albedo exhibits a modest positive correlation with total vegetation cover and a modest negative correlation with rock and soil exposure. The strongest positive correlation was found between albedo and moss cover. The differences in brightness between moraines and outwash deposits are evident visually at the landscape scale on satellite photographs and quantifiable by image-processing software. [ABSTRACT FROM AUTHOR]

Topography exerts a strong control on how glaciers respond to changes in climate. Increased understanding of this role is important for both refining model predictions of future rates of glacier recession and for reconstructing climatic change from the glacial geological record. In this paper, we examine the geomorphological and sedimentological evidence in the foreland of Fingerbreen, a temperate outlet of the plateau icefield Østre Svartisen. The aim is to investigate the relationship between processes of landform generation and the changing influence of topography as recession progressed. The Fingerbreen foreland is dominated by bouldery Little Ice Age moraines and extensive areas of striated bedrock. A heavily fluted zone occurs in the central part of the foreland that is cross‐cut by annual transverse and sawtooth moraines. Systematic investigations of the structural architecture of moraines at various locations in the foreland provide evidence for a range of moraine‐forming processes, which can be linked to the topographic setting (e.g. deposition on a reverse bedrock slope) and drainage conditions. This includes push and bulldozing of proglacial sediments and squeezing of sub‐glacial sediments and submarginal freeze‐on of sediment slabs. We also identify variations in moraine spacing as a result of topography. This research demonstrates the importance of topography when interpreting moraine records in the context of climate and glacier dynamics. [ABSTRACT FROM AUTHOR]

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Ongoing speculation regarding the existence of large Late Pleistocene ice masses in Northeast Eurasia reflects the dearth of age constraints on glaciations across this vast region. Here, we report the first dates from the central part of Northeast Siberia, consisting of 22 cosmogenic 10Be exposure ages from boulders deriving from a sequence of three moraines in the Chersky Range. The dated moraine sequence indicates progressive contraction of maximum glacier extent from Marine Isotope Stage 6 to the Last Glacial Maximum, while the remotely‐sensed mapping indicates an older, more expansive glaciation in the region yet undated. Our results show that Late Pleistocene glaciations were limited to the highlands, and Northeast Siberia did not host a large, coalescent ice sheet during the Last Glacial Maximum or Marine Isotope Stage 6. Plain Language Summary: Very little is known about the glacial history of Northeast Siberia, which has led to speculations concerning the size and timing of past ice masses in this vast region. Some have previously suggested the area was covered by a large ice sheet during the Last Glacial Maximum 20 Kyr ago, but the consensus today maintains that the ice cover was limited due to restricted moisture sources. It is clear, however, that Northeast Siberia at one point in time hosted large ice masses, as the region is home to extensive glacial landforms of unknown age. We use cosmogenic 10Be exposure dating to study a glacial moraine complex with three well‐defined moraine ridges in the Chersky Range located in central Northeast Siberia. Our results show that the youngest and innermost moraine was emplaced toward the end of the Last Glacial Maximum, whereas the oldest and outermost moraine was emplaced during the penultimate glaciation ∼130 Kyr ago. This suggests that Northeast Siberia did not host a large ice sheet during the Late Pleistocene, and that the ice cover was limited to mountain glaciers. Satellite‐based mapping of glacial landforms confirms the existence of at least one older, more expansive glaciation that remains undated. Key Points: Be‐10 exposure ages from moraines in the Chersky Range show that glaciers in central NE Siberia contracted over the last two glacial cyclesNortheast Siberia hosted mountain‐centered icefields during the Late Pleistocene, but no large‐scale continental ice massesLargest ice extent in the Chersky Range predates the penultimate glacial cycle and likely occurred during the Mid‐Pleistocene super‐glacials [ABSTRACT FROM AUTHOR]

This study uses luminescence and 14C accelerator mass spectrometry procedures to date relevant glaciofluvial and glacial deposits from the south-central and southeastern Pyrenees (Andorra–France–Spain). We distinguish two types of end-moraine complexes: (1) those in which at least a far-flung moraine exists beyond a frequently nested end-moraine complex (the most common) and (2) those in which a closenested end moraine encompasses at least two glacial cycles. Both types formed within six distinctive glacial intervals: (1) A penultimate glacial cycle during Marine Oxygen Isotope Stage (MIS) 6 and older glaciofluvial terraces occurred beyond the range of the luminescence dating method. (2) An early glacial advance in MIS 5d (∼97 −15/+19 ka) was followed by glacial retreat during MIS 5c (< 91 ± 9 ka). (3) The last maximum ice extent (LMIE) was in early MIS 4 (∼74 ± 4.5 ka). (4) Unexpectedly, glaciers thinned during the second half of MIS 3 (∼39 −6/+11 ka). (5) During the MIS 3–2 transition, glaciers subsequently fluctuated behind the LMIE limits. (6) The global last glacial maximum (LGM) started as early as ∼26.6 ± 0.365 ka b2k, and the corresponding end moraines were built behind the LMIE limits or merged with it, forming close-nested moraines. [ABSTRACT FROM AUTHOR]

Dendrochronology, and lichenometry were used to determine the relative and absolute age of the Late Holocene moraines of the glaciers of the Aktru, Maashei and Shavla valleys (North Chuya ridge, Central Altai). An array of 86dendrochronological dates, related to moraine deposits, is analyzed, 30 of which are published for the first time. Also, for the first time, data on the relative (lichenometric) age of the young deposits of the Aktru Valley, and data on the lichenometry of the moraines of the Maashey glacier and one of the glaciers of the Shavly valley were obtained. We used the capabilities of each method and the expediency of their combined use in the study area. It was confirmed that the growth rates of lichens on the moraines of the Aktru stage (XVIII–XIX centuries) are generally consistent with the previously published estimates. The moraines of the Historical stage, which date earlier than 1700–2300 years ago, supports the lichens as large as 120–160 mm, but the scattering of their diameters is too large and the assessment of the lichenometric ages of these moraines seems to be problematic, but not completely excluded. The Akkem stage of glacier advance according to the recent publications dates back to the Late Glacial or Early Holocene time; the lichenometry is obviously not applicably at such ancient surfaces. According to dendrochronological dating, the glaciers of the North Chuisky Ridge in the last millennium advanced at least twice up to their maximum extent in the XVII– early XIX and XII centuries. In the 8th century, the sizes of the glaciers possibly, approached modern ones. Aſter the XVII century, the cedar (Pinus Sibirica) in Central Altai significantly reduced its distribution area due to the climate cooling, retreating from the periglacial territories, where it was distributed earlier. All trees that grew near the glaciers, above 2300 m, died. The comparison of the dates of glacier advances in the past millennia with the tree-ring, ice-core, and palynological reconstructions of summer temperature and precipitation show a good correspondence.

Rockwall erosion in high-alpine glacial environments varies both temporally and spatially. Where rockwalls flank glaciers, changes in debris supply and supraglacial cover will modify ice ablation. Yet, quantifying spatiotemporal patterns in erosion across deglaciating rockwalls is not trivial. At five adjacent valley glaciers around Pigne d'Arolla in Switzerland, we derived apparent rockwall erosion rates using 10Be cosmogenic nuclide concentrations ([10Be]) in medial moraine debris. Systematic downglacier-sampling of six medial moraines that receive debris from rockwalls with differing orientation, slope and deglaciation histories enabled us to assess rockwall erosion through time and to investigate how distinct spatial source rockwall morphology may express itself in medial moraine [10Be] records. Our dataset combines 24 new samples from medial moraines of Glacier du Brenay, Glacier de Cheilon, Glacier de Piεave;ce, and Glacier de Tsijiore Nouve, with 15 published samples from Glacier d'Otemma. For each sample, we simulated the glacial debris transport using a simple debris particle trajectory model, to approximate the time of debris erosion and to correct the measured [10Be] for post-depositional 10Be accumulation. Our derived apparent rockwall erosion rates range between ~0.6 and 10.0 mm yr-1. Whereas the longest downglacier [10Be] record presumably reaches back to the end of the Little Ice Age (LIA) and suggests a systematic increase in rockwall erosion rates over the last ~200 years, the shorter records only cover the last ~100 years from the recent deglaciation period and indicate temporally more stable erosion rates. For the estimated time of debris erosion, ice cover changes across most source rockwalls were small, suggesting that our records are largely unaffected by the contribution of recently deglaciated bedrock of possibly different [10Be]; but admixture of subglacially derived debris cannot be excluded at every site. Comparing our sites suggests that apparent rockwall erosion rates are higher where rockwalls are steep and north-facing, indicating a potential slope and temperature control on rockwall erosion around Pigne d'Arolla. [ABSTRACT FROM AUTHOR]

Be they a product of either an anthropogenic or a glacigenic nature, ponds within forests play an extremely important role in determining hydrological features of forest microcatchments. Water retained in these small bodies of water for example has a positive effect on the groundwater of neighbouring forest habitats, serving to recharge them during dry periods. This article presents the results of a study conducted in the catchments of two mid-forest ponds (known as Nos. 1 and 5), which differ in terms of their recharge characteristics. The ponds are located on the land of Poland's Siemianice Experimental Forestry Department, in the catchments of the Rivers Niesob and Pomianka as left-bank tributaries of the Prosna. The forests are located on the Southern Wielkopolska Lowland, on the Wieruszow Plateau, which is a denuded moraine plain incised by the upper Prosna. The study was carried out in the three hydrological years 2013, 2015 and 2016, which differed in terms of their precipitation totals. The 2013 hydrological year, in which precipitation totalled 711 mm (hence 139 mm above the multi-year average) was a wet year, as compared with the very dry hydrological year 2015, which featured a precipitation total of 337 mm, or just 59% of normal precipitation. The third hydrological year discussed (2016) proved to be an average year, with precipitation totalling 613 mm thus being 41 mm above the multi-year average. [ABSTRACT FROM AUTHOR]

Aerial photographs of the European Alps usually only reach back to the middle of the 20th century, which limits the time span of corresponding studies that quantitatively analyse long-term surface changes of proglacial areas using georeferenced orthophotos. To the end of the Little Ice Age, this leads to a gap of about 100 years. Using digital monoplotting and several historical terrestrial photographs, we show the quantification of surface changes of a Little Ice Age lateral moraine section until the late second half of the 19th century, reaching a total study period of 130 years (1890–2020). The (initial) gully system expands (almost) continuously over the entire study period from 1890 to 2020. Until 1953, the vegetation-covered areas also expanded (mainly scree communities, alpine grasslands and dwarf shrub communities), before decreasing again, especially between 1990 and 2003, due to large-scale erosion within the gully system. Furthermore, our results show that the land-cover development was impacted by temperature and precipitation changes. With the 130-year study period, we contribute to a substantial improvement in the understanding of the processes in the proglacial by analysing the early phase and thus the immediate response of the lateral moraine to the ice exposure. [ABSTRACT FROM AUTHOR]

Previous interpretation of the nature and distribution of subaerial glacial landforms established that Frobisher Bay in southeastern Baffin Island was glaciated in the Late Wisconsinan by ice flowing southeast from the Foxe–Baffin Ice Dome. New seafloor mapping within the bay has revealed submarine glacial landforms that are described and interpreted in the context of their subglacial, ice‐marginal, glaciomarine and marine process environments. Interpretation of the evidence confirms that ice occupied Frobisher Bay, flowing from the northwest to southeast, parallel to the orientation of the bay. Relatively rapid ice velocities are indicated by the presence of ice‐moulded bedrock and megaridges flanking a deep trough (>700 m) along the faulted southern flank of Frobisher Bay. In shallower regions, areal scouring and channelisation indicate the widespread presence of glacial ice. As ice retreated to the northwest towards the Foxe Ice Dome, De Geer and recessional moraines were deposited at the ice front. The latter correlate spatially with the extensive Frobisher Bay Moraine System on land. Two iceberg ploughmark populations are evident, with smaller relict features in shallow water in rare locations in the northwest of the bay, and larger relict and modern ploughmarks in deeper water in outer Frobisher Bay. [ABSTRACT FROM AUTHOR]

This paper aims to evaluate the effects of blended binders on the development of strength in moraine soils by optimising the proportion of several binders. We tested three types of soil as a mixture of moraine soils: A (sandy clay), B (clayey silt) and C (silty clay), collected in southern Sweden. The soil was compacted using a modified Proctor test using the standard SS-EN 13286-2:2010 to determine optimum moisture content. The particle size distribution was analysed to determine suitable binders. The specimens of types A, B and C, were treated by six different binders: ordinary Portland cement (OPC); hydrated lime (Ca(OH)2); ground granulated blast furnace slag (GGBFS) and their blends in various proportions. The strength gain in soil treated by binders was evaluated by the test for Unconfined Compressive Strength (UCS) against curing time. For soil type A, the strength increase is comparable for most of the binders, with the difference in behaviour in the UCS gain. The OPC/lime, GGBFS and hydrated lime showed a direct correlation, while OPC, OPC/GGBFS and GGBFS/hydrated lime - a quick gain in the UCS by day 28th. After that, the rate of growth decreased. Compared to soil type A, Ca(OH)2 performs better on the stabilisation of soil type B. Besides, the hydrated lime works better on the gain of the UCS compared to other binders. The GGBFS/Ca(OH)2 blend shows a notable effect on soil type A: the UCS of soil treated by Ca(OH)2 performs similarly to those treated by OPC with visible effects on day 90th. Cement and a blend of slag/hydrated lime demonstrated the best results for soil type B. An effective interaction was noted for the blends GGBFS and hydrated lime, which is reflected in the UCS development in soils type A and B. Blended binder GGBFS/hydrated lime performs better compared to single binders. [ABSTRACT FROM AUTHOR]

Initially a matter of intellectual curiosity, but now important for understanding ice‐sheet dynamics, the formation of subglacial bedforms has been a subject of scientific enquiry for over a century. Here, we use a numerical model of the coupled flow of ice, water, and subglacial sediment to explore the formation of subglacial ribs (i.e., ribbed moraine), drumlins and mega‐scale glacial lineations (MSGLs). The model produces instabilities at the ice–bed interface, which result in landforms resembling subglacial ribs and drumlins. We find that a behavioural trajectory is present. Initially subglacial ribs form, which can either develop into fields of organized drumlins, or herringbone‐type structures misaligned with ice flow. We present potential examples of these misaligned bedforms in deglaciated landscapes, the presence of which means caution should be taken when interpreting cross‐cutting bedforms to reconstruct ice flow directions. Under unvarying ice flow parameters, MSGLs failed to appear in our experiments. However, drumlin fields can elongate into MSGLs in our model if low ice–bed coupling conditions are imposed. The conditions under which drumlins elongate into MSGLs are analogous to those found beneath contemporary ice streams, providing the first mechanism, rather than just an association, for linking MSGLs with ice stream flow. We conclude that the instability theory, as realized in this numerical model, is sufficient to explain the fundamental mechanics and process‐interactions that lead to the initiation of subglacial bedforms, the development of the distinctive types of bedform patterns, and their evolutionary trajectories. We therefore suggest that the first part of the longstanding 'drumlin problem' – how and why they come into existence – is now solved. However, much remains to be discovered regarding the exact sedimentary and hydrological processes involved. [ABSTRACT FROM AUTHOR]

On a glacier foreland of the Central Austrian Alps, a permanent plot study was performed to investigate the successional pathway on two moraines. We expected that the pioneer stage deglaciated for 25 years will converge to an early successional stage after another 25 years and the early stage deglaciated for 40 years will show trends toward a late successional stage. Different dynamics of species occurrence such as colonization/persistence and cover increase/decrease, were anticipated. Twenty plots of 25 × 25 cm were established in 1996 on each successional stage by selecting vegetated and bare ground plots to account for impacts of facilitation on seedling recruitment. We expected seed and establishment limitations, therefore, also effects of sowing were studied on sown and control plots. Species enrichment occurred on all control and sown plots of both stages. However, the pioneer stage did not converge to an early successional stage as it was expected. On the early successional stage, only on sown plots a development toward a late successional stage was found. Bryophyta were the most efficient colonizers on all plots together with the lichen Stereocaulon alpinum at the pioneer stage and the sown species Anthyllis vulneraria ssp. alpicola at the early successional stage. The pioneer species Saxifraga oppositifolia was still present after 25 years on the pioneer and early successional stages, although its cover significantly decreased. We conclude that seed and establishment limitations, drought, facilitation deficits, and ageing of individuals are the essential drivers on the studied glacier foreland, creating 'quasi-stationary' communities. [ABSTRACT FROM AUTHOR]

On 25 June 2020, a glacial lake outburst flood (GLOF) occurred in Jinwuco, Nidou Zangbo, and southeast Tibet, causing catastrophic damage to multiple infrastructures such as roads, bridges, and farmlands in the surrounding and downstream areas. Due to the lack of long-term monitoring of glacial lake and glacier changes in the region and the surrounding surface, the spatial and temporal evolutionary characteristics and triggering factors of the disaster still need to be determined. Here, we combine multi-temporal optical remote sensing image interpretation, surface deformation monitoring with synthetic aperture radar (SAR)/InSAR, meteorological observation data, and corresponding soil moisture change information to systematically analyze the spatial and temporal evolution characteristics and triggering factors of this GLOF disaster. Optical images taken between 1987 and 2020 indicate that the glacial lake's initial area of 0.39 km2 quickly grew to 0.56 km2, then plummeted to 0.26 km2 after the catastrophe. Meanwhile, we found obvious signs of slippage beside the lateral moraine at the junction of the glacier's terminus and the glacial lake. The pixel offset tracking (POT) results based on SAR images acquired before and after the disaster reveal that the western lateral moraine underwent a 40 m line of sight (LOS) deformation. The small baseline subset InSAR (SBAS-InSAR) results from 2017 to 2021 show that the cumulative deformation of the slope around the lateral moraine increased in the rainy season before the disaster, with a maximum cumulative deformation of −52 mm in 120 days and gradually stabilized after the disaster. However, there are three long-term deformation areas on the slope above it, showing an increasing trend after the disaster, with cumulative deformation exceeding −30 mm during the monitoring period. The lateral moraine collapse occurred in a warm climate with continuous and intense precipitation, and the low backscatter intensity prior to the slide suggests that the soil was very moist. Intense rainfall is thought to be the catalyst for lateral moraine collapse, whereas the lateral moraine falling into the glacier lake is the direct cause of the GLOF. This study shows that the joint active–passive remote sensing technique can accurately obtain the spatial and temporal evolution characteristics and triggering factors of GLOF. It is helpful to understand the GLOF event caused by the slide of lateral moraine more comprehensively, which is essential for further work related to glacial lake hazard assessment. [ABSTRACT FROM AUTHOR]

The seabed landscape around the Summer Isles (NW Scotland) hosts classic examples of subaqueous moraines formed at a Late Pleistocene tidewater ice-sheet margin. This suite of moraines, now within the Wester Ross Marine Protected Area, records oscillatory retreat of the grounding line of (one or more) large outlet glaciers receding from the open waters of the Minch into the fjords of Loch Broom and Little Loch Broom at the end of the last (Weichselian / Devensian) glaciation. The moraines, probably the best-studied examples in UK waters, formed by a combination of pushing, dumping and/or squeezing of sediment at the grounded tidewater glacier front. Their absence in some basins suggests that the glacier front was un-grounded (partially floating) in areas of deeper water. Some of these seabed moraines can be connected to ice-sheet moraines onshore, assigned to the Wester Ross Readvance, and dated to ca. 15.5 ka BP. Geomorphological evidence strongly suggests that the whole sequence represents relatively slow and punctuated ice-front retreat over a period of decades to centuries. Continued protection of these rare and distinctive seabed moraines is important, both on geological and ecological grounds. The moraines represent the first underwater Scottish Landform Example in this long-running series. [ABSTRACT FROM AUTHOR]