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Piedmont glaciers (lobes), typically found in high latitudes and large mountainous regions, extend from ice sheets and ice caps to lower altitudes. However, they can also occur, although less commonly, on mid‐latitude mountains. When these fan‐like glaciers retreat, they leave behind hummocky moraines scattered in a chaotic pattern. In this study, we have mapped one of these mid‐latitude sites and established a Terrestrial cosmogenic nuclide (TCN) glacial chronology on Mount Davraz, namely Davraz hummocky moraine field (37°46′00″N, 30°43′15″E). Our findings indicate that the glaciers in this area started receding from the early local Last Glacial Maximum (LGM) period (21.8 ± 2.4 ka) to the early Late‐glacial period (17.7 ± 2.2 ka), and eventually disappearing. The deglaciation of the Mt. Davraz palaeoglacier matches nearby mountains, supported by southerly winds as significant for regional glaciation. Our discoveries reveal a robust connection between southerly winds and nearby glaciation, contributing to our understanding of how climate influences glaciers. Likewise, the glacial timelines of the neighbouring mountains align with the glacial history of Mt. Davraz. [ABSTRACT FROM AUTHOR]

The retreat of mountain glaciers inevitably leads to an increase in the number of outburst moraine lakes. One of the possible mechanisms of moraine dam outburst along with overflow over the crest is the formation of a filtration channel in the body of the moraine dam (piping). An algorithm for calculating the outburst flood hydrograph, describing the development of a filtration channel in the body of a moraine dam and the subsequent formation of water overflow when the soil above the channel collapses, is proposed in this paper. Verification of proposed methodology was carried out on the basis of experimental data and published data of real outbursts. Satisfactory results verifying this methodology made it possible to use the proposed methodology for the calculation of the hydrograph of the outburst of Lake Bashkara in the Elbrus region, which occurred on 1 September 2017. It is shown that the simulation results are quantitatively comparable with the estimates obtained from field data: the time of water discharge through the channel was 16 min, the period of the outburst wave passage was 40 min, and the maximum discharge was 636 m3/s. Thus, the possibility of applying the proposed methodology for calculating the destruction of natural moraine dams has been demonstrated. [ABSTRACT FROM AUTHOR]

Glaciers reflect integrated climate signals from inter-annual to centennial timescales. In using glacier extent as a climate-change detector, the challenge is to distinguish the roles of the inter-annual climate variability and long-term climatic change on the glacier change. Using cosmogenic nuclide 10Be dating method and glacier dynamical models, this study numerically reconstructed glacier extents at ~ 1850s AD (latest Little Ice Age period) in the Keqiong Qu I, Keqiong Qu II, Taqiong Qu I, and Taqiong Qu II valleys around the Kuoqionggangri peak, southern Tibetan Plateau, and quantified the effects of inter-annual summer temperature variability and long-term summer temperature change on the glacier retreats since then. Without change in mean annual precipitation, the summer temperature decrease of 0.40–0.53 °C from present was required to sustain the glacier lengths at their respective ~ 1850s AD moraines in the four valleys. The climate inferences from the glacier-climate modeling were similar to reconstructions at other glaciers on the Tibetan Plateau and the changes in long term climate reanalysis (HadCRUT5, BEST and NOAA 20CR v3). Forced by the inter-annual variabilities in summer temperature and annual precipitation, the glaciers had excursions of 150–200 m (5–8% of their lengths) from the ~ 1850s AD moraines. We therefore argued that the climate change was largely responsible for the glacier retreats from the ~ 1850s AD moraine positions in the region. [ABSTRACT FROM AUTHOR]

ABSTRACTWe 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.

To further elucidate the Late Pleistocene glacial history of mid-elevation mountainous regions in Central Europe, 10Be cosmic-ray exposure (CRE) dating was applied to moraines in the Zastler Tal Valley in the Southern Black Forest. Periods of glacier recession from moraines in this valley began no later than 16 ka, 15 ka, and 13 ka. CRE ages of moraines in this and other parts of the Southern Black Forest cluster around 17–16 ka and 15–14 ka, thus suggesting a common forcing of glacier recession. Equilibrium-line altitudes (ELAs) during moraine formation were calculated for precipitation reconstruction. Observed spatial discrepancies in ELAs at ca. 15–14 ka are explained best by the size of snow-contributing areas. The reconstructed annual precipitation at the ELA for ca. 16 ka and ca. 15 ka is affected by large uncertainties, representing a wide range from ~50% to ~150% of present-day values. Due to various factors, such as drifting snow, the lower bounds of the estimates appear most realistic, thus concurring with the common hypothesis of less precipitation during the last glacial termination than today in Central Europe. Further research is needed before ELAs of small ice masses can be employed for precise precipitation estimates. [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]

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]

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]

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]

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]

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]

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]

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]

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]

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]

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]

Since the end of the Little Ice Age (LIA) in the middle of the 19th century, Alpine glaciers have been subject to severe recession that is enhanced by the recent global warming. The melting glaciers expose large areas with loose sediments in the form of lateral moraines, amongst other forms. Due to their instability and high slope angle, the lateral moraines are reworked by geomorphological processes such as debris flows, slides, or fluvial erosion. In this study, the development of the morphodynamics and changes in geomorphological processes on lateral moraines were observed over decades, based on a selection of 10 glacier forefields in the Eastern Alps. To identify geomorphological changes over time, several datasets of archival aerial images reaching back to the 1950s were utilized in order to generate digital elevation models (DEMs) and DEMs of difference. The aerial images were complemented by recent drone images for selected moraine sections, enabling a high-resolution analysis of the processes currently occurring. The results concerning the development of morphodynamics on lateral moraine sections are diverse: some slopes display a stagnation of the erosion rates, whereas the rates of one section increase significantly; however, the majority of the slopes show a decline in morphodynamics over decades but stay on a high level in many cases. In particular, moraine sections with high morphodynamics at the beginning of the observation period mostly show high erosion rates up until present-day measurements, with values up to 11 cm yr -1. These moraine sections also feature heavy gullying on their upper slopes. A correlation between the development of morphodynamics and the time since deglaciation could scarcely be established. In fact, the results instead indicate that characteristics of the lateral moraines such as the initial slope angle at the time of deglaciation have a significant influence on the later morphodynamics. These observations raise concerns as to whether the until now often conducted analyses based on the comparison of lateral moraine sections with different distances to the glacier terminus, assumed to represent varying time spans since deglaciation, can provide sound evidence concerning the process of stabilization. [ABSTRACT FROM AUTHOR]

We assess the evolution of glaciological structures during the 2003–05 surge in the Paulabreen glacier system, Svalbard. Glaciological structures on the glacier surface were mapped using aerial photographs captured in the early stages of the surge (2003) and 5 years after surge termination (2011). Three-dimensional measurements of glaciological structures were collected at the tidewater front in 2013. These datasets document the physical changes during (1) the late quiescent phase; (2) the early phase of the surge as the surge front propagated down Skobreen and advanced into Paulabreen and (3) the final stages of the surge following the surge front reaching the glacier terminus. Crevasse patterns and clusters of arcuate shear planes record zones of compressive and extensional flow associated with the downglacier progression of the surge front. The transfer of surging ice from Skobreen into Paulabreen caused lateral displacement of the medial moraines to the northeast. At the ice front, this movement tilted glaciological structures in the same direction. Structures at the southwest margin record strike–slip faulting and the elevation of debris into the ice in a zone of compression and transpression. We summarise these observations in a schematic reconstruction of structural evolution during the surge. [ABSTRACT FROM AUTHOR]

Mid‐latitude Patagonian glaciers are sensitive to changes in the complex coupled ocean–atmospheric climate system of the Southern Hemisphere. Here, we investigate glacier response to a period of rapid climate warming immediately post‐dating the Antarctic Cold Reversal (ACR). We analyse a sequence of 13 ice margins, four of them dated, from an outlet valley of the Monte San Lorenzo ice cap (47.3°S). We constrain glacier recession of 31.7 km over a period of ~1 kyr from 13.2 ± 0.4 to 12.1 ± 0.4 ka. The average rate of recession was 35.2 m a−1 over this 1‐kyr period, increasing from 12.75 m a−1 at the start of the record (moraines M1 to M4) to 50 m a−1 from M9 to M12. This recession occurred during a period of rapid warming when the austral westerlies shifted polewards. It is likely that ice extent stabilized during the Holocene, with ice occupying the M13 moraine during repeated Holocene neoglacials, before anthropogenic warming caused recession at a rate of 55.5 m a−1 from 1985 to 2016. We conclude that 20th century rates of recession were higher than those during post‐ACR warming, though of a similar order of magnitude. [ABSTRACT FROM AUTHOR]

Debris-covered glaciers have contrasting melting mechanisms and climate response patterns if compared with debris-free glaciers and thus show a unique influence on the hydrological process. Based on high-resolution satellite images and unpiloted aerial vehicle surveys, this study investigated the dynamic changes of Zhuxi Glacier, a thick debris-covered glacier in the southeastern Tibetan Plateau. Our result shows that the whole glacier can be divided into the active regime and stagnant regime along the elevation of 3400 m a.s.l. The mean surface velocity of the active regime was 13.1 m yr−1, which was five times higher than that of the stagnant regime. The surface-lowing rate of this debris-covered glacier reaches more than 1 m yr−1 and displays an accelerating trend. The majority of ice loss concentrates around ice cliffs and supraglacial ponds, the ablation hotspots. These hotspots can be roughly classified into three types, including persistent, expanding, and shrinking patterns, at different dynamic regimes on the Zhuxi Glacier. With the evolution of these hotpots and glacier dynamic changes, the supraglacial ponds showed significant change, with the total number fluctuating from 15 to 38 and the total area increasing from 1128 m2 to 95790 m2 during the past decade. The recent exponential expansion of the proglacial lake and the significant downwasting of stagnant ice inside the dammed terminus moraine possibly trigger the glacial lake outburst flood and thus threaten the security of livelihoods and infrastructure downstream. [ABSTRACT FROM AUTHOR]

In the summer of 1838, Arnold Guyot was asked by Louis Agassiz to gather information on Alpine glaciers, with the aim of reporting their findings in September, at the annual gathering of the French Geological Society. Guyot's observations of the internal structure of the ice and interpretations on glacier movements, reported orally at the conference, were new to science. Unfortunately, because of purported illness, Guyot did not send his manuscript to be published and missed his first opportunity to be recognized as a pioneer in glacier studies. During the years 1841 to 1847, Guyot published a series of notes, detailing results of his field work in tracing erratic blocks in the central Alpine region, in the Alpine foreland and in the Jura Mountains. The level of detail in his work was unprecedented and has not been replicated since. Recognizing that erratic blocks of similar lithology could be followed along organized paths of deposition, Guyot could invalidate those theories that sought to explain their deposition by chaotic means, such as floods, debacles or drifting icebergs loaded with rock debris. Only moraines, composed of material transported by glaciers, could explain the mapped arrangements of erratic blocks. Geological proofs for extensive glaciations in central Europe had just been found, and Guyot could demonstrate them on his hand-drawn map. But, in 1848, a revolution broke out in Neuchâtel. The local academy where Guyot was engaged as a professor shut down and all staff were left without pay. Answering a call from Agassiz who had emigrated to the USA in 1846, Guyot departed Switzerland and joined his friend there in the fall of 1848. In his luggage were all the papers on his unfinished project, including his map, and a full collection of erratic rock specimens. After arrival in the USA, Guyot had to begin a new professional life and could not devote significant attention to the subject of erratic blocks. In 1849, he showed his map of the erratic basins of Switzerland and discussed his results with various members of the American Association for the Advancement of Science (AAAS); he also shared his novel ideas about the climatic conditions required for the formation of large glaciers; however, he did not formally publish the results of his work in the Alps, and he thus lost his second opportunity for wider peer recognition and for driving the acceptance of the glacial theory. Only in 1874, 26 years after his arrival in the USA and a year after Agassiz's death, did Guyot open his boxes of alpine rock specimens and display his unpublished map in the Museum of the College of New Jersey (later Princeton University), where he was engaged as a professor. In 1883, at age 77, his memory of the unpublished 1838 report on glaciers was still in his conscience which finally pushed him to submit it for printing at Neuchâtel. It passed largely unnoticed, however, and Guyot died one year later without recognition attached to his name for his original, innovative work. This paper reviews Guyot's work and analyses his relationship with Agassiz while both were working in Neuchâtel. It seeks to evaluate his pioneering work on glaciers and on erratic blocks. It includes a copy of Guyot's map of the erratic basins of Switzerland, kept to this day in the archives of Princeton University. [ABSTRACT FROM AUTHOR]

The results of investigations of the landforms and sediments in the marginal zone of the Aldegonda Glacier are presented. As a result of the geomorphological analysis of the Aldegonda Glacier proglacial zone, geological and geomorphological indicators of its surge behavior in the Little Ice Age (700–100 yr BP) were proposed on the basis of the features and velocities of ice propagation and degradation during the phases of advance and retreat. These features were reconstructed from the configuration of lateral moraines and from the location of terminal moraines (submarine and terrestrial) and according to the historical data. Two different age generations of ridges of the left lateral moraine were distinguished. The young lateral moraine (dated to the Little Ice Age) is oriented parallel to the axis of glacier movement, and the ancient one (older than 12 cal ka BP) is at an angle to it. The difference in orientation is caused by a different velocity of the glacier movement that was slower before 12 ka BP and more rapid at 700–100 yr BP. Different mechanisms were established for the formation of two terminal moraines: pushing (below sea level) and dumping (on land). The first one was interpreted as a result of the rapid glacier advance, and the second one, because of the stabilization of the glacier front during the areal degradation of the terrestrial part of the glacier's advanced tongue, followed by its rapid retreat, as was established by the historical information. Landform-indicators, such as fluted moraine and crevasse-fill ridges, were suggested as additional geomorphological features of the surge behavior. [ABSTRACT FROM AUTHOR]

Simple Summary: Adaptative extremophiles are frequently found in various glacial ecological niches, such as glacial meltwater, ice, snow, and permafrost. However, no systematic study has investigated the diverse and temporary survival of culturable bacteria in newly exposed moraines around glacier snouts. The findings of this study revealed the diversity of culturable heterotrophic bacteria in a newly exposed moraine and demonstrated the evolution, competition, and selective growth of bacteria facing primary succession. This study not only helps to understand the high diversity of culturable bacteria in the newly exposed moraine at a glacier snout but also provides a theoretical basis for the study of microbial resources surviving in the transition region between glaciers and retreats. Laohugou Glacier No. 12 is located on the northern slope of the western Qilian Mountains with a temperate continental wet climate and an extremely cold winter. Bacteria in a newly exposed moraine have to cope with various pressures owing to deglaciation at the glacier snout. However, limited information is available regarding the high diversity and temporary survival of culturable heterotrophic bacteria under various environmental stresses. To examine the tolerance of extremophiles against varying environmental conditions in a newly exposed moraine, we simulated environmental stress in bacterial cultures. The results showed that the isolated strains belonged to actinobacteria, Proteobacteria, Bacteroidetes, Deinococcus-Thermus, and Firmicutes. Actinobacteria was the most abundant phylum, followed by Proteobacteria, at both high and low temperatures. Pseudarthrobacter was the most abundant genus, accounting for 14.2% of the total isolates. Although several microorganisms grew at 10 °C, the proportion of microorganisms that grew at 25 °C was substantially higher. In particular, 50% of all bacterial isolates grew only at a high temperature (HT), whereas 21.4% of the isolates grew at a low temperature (LT), and 38.6% of the isolates grew at both HT and LT. In addition, many radiation-resistant extremophiles were identified, which adapted to both cold and oxidative conditions. The nearest neighbors of approximately >90% of bacteria belonged to a nonglacial environment, such as oil-contaminated soil, rocks, and black sand, instead of glacial niches. This study provides insights into the ecological traits, stress responses, and temporary survival of culturable heterotrophic bacteria in a newly exposed moraine with variable environmental conditions and the relationship of these communities with the non-glacial environment. This study may help to understand the evolution, competition, and selective growth of bacteria in the transition regions between glaciers and retreats in the context of glacier melting and retreat owing to global warming. [ABSTRACT FROM AUTHOR]

Proglacial areas in the European Alps and other high-elevation mountains are currently undergoing rapid change due to global warming. Because of rising temperatures, glaciers and glacier forefields are subjected to increased melting and associated sediment export. This observation is increasingly important with respect to high-elevation geomorphological and ecological dynamics, emerging natural hazards and mitigation efforts, and hydropower plant management. It is therefore crucial to analyze the factors and feedback mechanisms governing sediment production, transport, and deposition in these rapidly changing areas. In this study, we investigated the sediment dynamics of a proglacial area located in the Eastern Italian Alps over the period 1969–2021 with the aims of: i) identifying the areas of sediment production; ii) quantifying volumes and rates of bedload sediment transport; and iii) determining the relative contribution of glacial export and fluvial erosion to the total sediment budget. We found that i) apart from glaciers, moraines and fluvial channels have been the most important sediment sources, albeit with substantial differences in terms of connectivity and thus supply rates; ii) the volumes and rates of sediment erosion varied by one order of magnitude (between tens and hundreds of mm per year), and were generally higher along the channel network; and iii) for a relatively shorter time interval between 2005 and 2021, the relative contribution of glacial bedload input with respect to the total sediment budget ranged between 34 % and 37 %, whereas 45 % to 59 % was derived from lateral fluvial erosion. Only a relatively small sediment volume was generated by net channel bed incision. These results imply that most of the sediment released from the proglacial area of the Sulden glacier is progressively transferred to the downstream sector of the channel network, with volumes that range between 931 and 1017 tons yr−1 km−2. These values are in the typical range of sediment export volumes from glaciated basins and highlight the high dynamicity of this region of the Alps. In general, our results confirm the complexity – in terms of spatial and temporal variability – of Alpine proglacial systems and highlight the need to systematically study these areas on a wide spatial and temporal scale, since the information provided by single locations or individual sectors of the sediment cascade, may not be adequate for understanding the dynamics acting in the entire proglacial regions. [Display omitted] • Proglacial areas change rapidly and supply sediment to the downstream valleys. • Moraines and channels are the most important sediment sources. • Glacial and fluvial erosion contribute between 35 % and 50 % to the sediment budget. • The proglacial area of the Sulden glacier is dominated by sediment transport. • In the Sulden region, sediment export may increase in the near future. [ABSTRACT FROM AUTHOR]

The erosional and depositional landforms modified by the glaciers can be used effectively to reconstruct the palaeo-glacial events along with dating techniques. In this study, a detailed reconstruction of the Satopanth Glacier (SPG), Bhagirath Kharak Glacier (BKG), and Bhagnyu Glacier (BG) in the Alaknanda Basin of Central Himalaya is carried out using glacier morphological features identified from a comprehensive dataset that includes historic toposheets (1882–1962), satellite images (1968–2020), and field observations (2019 & 2020). We also compute paleo, contemporary ice thickness, and glacier volumes using the Glacier Reconstructio (GlaRe) and the Himalayan Glacier Thickness Mapper (HIGTHIM) tools, respectively. Our results demonstrate that the region has witnessed three major glacial advances: Stage I (oldest), Stage II, and Stage III glaciations. The SPG, BKG, and BG were tributaries of a primary primitive glacier that existed during the Stage I glaciation that extended to the Mana village. The Stage I glacial moraines are at a distance of 8.4 ± 1.1 km, 7.8 ± 1 km, and 8.4 ± 1.1 km from the present-day snout of SPG, BKG, BG, while the Stage II moraines are 5.1 ± 0.71 km, 4.2 ± 0.58 km, and 5 ± 0.7 km away, and Stage III moraines are 1.9 ± 0.26 km, 1.3 ± 0.18 km, and 2.8 ± 0.39 km away, respectively. The area of the primitive glacier reduced (Stage I to the recent period) from 78 ± 4.6 km2 to 60 ± 3.6 km2 with a volume reduction from 4.7 ± 0.94 km3 to 3.5 ± 0.63 km3. Most importantly, the rate of recession of the glaciers in the Alaknanda Basin is more in the last 5 decades ∼(8.4 ± 1.1 m a−1 (SPG), 7.2 ± 1 m a−1 (BKG), 10 ± 1.4 m a−1 (BG)) than that reported over the last 12,000 years, which is ∼0.42 m a−1 (SPG), 0.35 m a−1 (BKG), 0.42 m a−1 (BG). The present study provides a detailed characterization of the long-term evolution of glaciers in the Alaknanda Basin for the first time. [Display omitted] • Paleoextent of 3 major glaciers in the Alaknanda Basin using satellite and field data • Paleo and contemporary ice thickness estimation using Laminar flow and GlaRe models • Observed 23 % volume and area reduction of glaciers between Stage I and III • Drastic glacier recession, ∼1.3 km to 2.8 km over the last 5 decades • Ice thickness stayed constant, 356–332 m, from Stage I to III. [ABSTRACT FROM AUTHOR]

The sedimentary record of Icelandic ice‐contact environments provides critical insights into past glacier margin dynamics and position, relative sea level, and the geomorphic processes that drive the evolution of proglacial environments. This important archive has been little exploited, however, with most glacier and sea‐level reconstructions based on limited sedimentary exposures, coring and surface geomorphic evidence. We report an extensive (42 km of data within a 24‐km2 study area) and deep (reflections recorded at depths up to 100 m) low‐frequency (40 and 100 MHz) ground‐penetrating radar (GPR) survey of the Sandgígur moraines, SE Iceland. GPR profiles reveal a much larger (67 m high) and extensive (1.25 km wide) buried moraine ridge than that suggested by surface topography (typically 125 m wide and 7 m high). These data reveal that the Sandgígur moraines was deposited during a major Holocene re‐advance of Skeiðarárjökull. The moraine ridge is buried by sediments dominated by glacifluvial deposits with an estimated sediment volume of 1.04 km3. We combine GPR‐derived subsurface architecture and the surface morphology to develop a conceptual model detailing the geomorphic evolution of the moraine and surrounding region. These results provide new insights into the Holocene evolution of Skeiðarársandur, identifying the presence of a former major ice‐margin position, as well as a past relative sea‐level limit. Furthermore, we establish that sediment supply and available terrestrial accommodation space are dominant drivers in the formation and evolution of vast sandar environments. [ABSTRACT FROM AUTHOR]

Olympus Mons (basement dimension is 550 × 600 km, absolute height is 21.1 km, relative elevation is 21.9 km, volume is 2.4 × 109 km3) is the largest volcanic edifice on Mars as well as on Earth. The Mars images of the regular combinations of features of volcanic and glacial forms on Olympus Mons have been interpreted and analyzed. The cardinal external similarity of these forms to the forms of large terrestrial tuyas of young volcanic regions was revealed. This, probably, testifies to their similar origin. The Olympus Escarpment, 3–6 km in height, bounds Olympus Mons at low latitudes (center is at 18° N, 113° E), which indicates that, during the formation of Olympus Mons, vast glaciers existed not only in the polar regions of Mars but far away from them. The distribution of extensive glacial moraines allowed us to evaluate the area of glaciation, equal to 1.5–2 × 106 km2, as well as the ice sheet thickness (about 3–6 km), comparable to the recent height of the Olympus Escarpment. Some distinct fragments of the glacial relief point to several phases of glaciations; the directions of the moraine lobe propagation record a clearly manifested asymmetry in the glacier distribution. In the SW, W, NW, N, and NE sectors of the Olympus Mons piedmont, the edge of the glacier was at a distance of 700–750 km from a crater; in the other zones, the glacier edge was at a distance of 500–600 km. Glacial and water-glacial formations, enriched in volcanic debris, are removed from the center of the volcano by colossal lahar-type mud-and-stone flows to the maximum (1100 km, Acheron Fossae) distance. These flows were formed as a result of the dramatical destruction of the walls of the glacial basin in which the Olympus tuya-volcano grew. A terrestrial analogue of a similar process is the catastrophic Jökulhlaup feature in Iceland, which is attributed to ice-filled calderas with volcanoes growing within them. [ABSTRACT FROM AUTHOR]

Retreating Glaciers in Himalayas are causing expansion of many glaciers lake, formed behind ice-'dam' or moraine dam and are big risk to the habitation and structures downstream. The unexpected breach in weak moraine lakes discharges huge volume of water and debris flow which are generally known as "Glaciers Lake Outburst Flood" (GLOF). This volume of water and debris can be millions of cubic meter in a short duration, resulting life threatening flooding in the downstream portion. These potentially dangerous lakes are analysed and identified on several factors like spread and condition of these lakes, the condition of dams, location of mother glaciers and some of the topographic feathers associated with lakes, dams, and glaciers. In this research work, the Chenab river basin originating in the Western Himalayan region has been taken to prepare the glacier lake inventory and also to recognize potentially vulnerable lakes. This study demonstrated a standard criterion of identification of vulnerable lakes/glacial lakes in the selected study area i.e. Chenab river basin. Taking lake area, type/location of lake and physical condition etc. as a standard parameter, two lakes have been found as potentially dangerous. [ABSTRACT FROM AUTHOR]

Climate change affects the stability and erosion of high‐alpine rock walls above glaciers (headwalls) that deliver debris to glacier surfaces. Since supraglacial debris in the ablation zone alters the melt behaviour of the underlying ice, the responses of debris‐covered glaciers and of headwalls to climate change may be coupled. In this study, we analyse the beryllium‐10 (10Be)‐cosmogenic nuclide concentration history of glacial headwalls delivering debris to the Glacier d'Otemma in Switzerland. By systematic downglacier‐profile‐sampling of two parallel medial moraines, we assess changes in headwall erosion through time for small, well‐defined debris source areas. We compute apparent headwall erosion rates from 10Be concentrations ([10Be]), measured in 15 amalgamated medial moraine debris samples. To estimate both the additional 10Be production during glacial debris transport and the age of our samples we combine our field‐based data with a simple model that simulates downglacier debris trajectories. Furthermore, we evaluate additional grain size fractions for eight samples to test for stochastic mass wasting effects on [10Be]. Our results indicate that [10Be] along the medial moraines vary systematically with time and consistently for different grain sizes. [10Be] are higher for older debris, closer to the glacier terminus, and lower for younger debris, closer to the glacier head. Computed apparent headwall erosion rates vary between ~0.6 and 10.8 mm yr−1, increasing over a maximum time span of ~200 years towards the present. As ice cover retreats, newly exposed headwall surfaces may become susceptible to enhanced weathering and erosion, expand to lower elevations, and contribute formerly shielded bedrock of likely different [10Be]. Hence, we suggest that recently lower [10Be] reflect the deglaciation of the debris source areas since the end of the Little Ice Age. [ABSTRACT FROM AUTHOR]

The dynamic response of large mountain glaciers to climatic forcing operates over timescales of several centuries and therefore understanding how these glaciers change requires observations of their behavior through the Holocene. We used Be‐10 exposure‐age dating and geomorphological mapping to constrain the evolution of glaciers in the Khumbu Valley in the Everest region of Nepal. Khumbu and Lobuche Glaciers are surrounded by high‐relief lateral and terminal moraines from which seven glacial stages were identified and dated to 7.4 ± 0.2, 5.0 ± 0.3, 3.9 ± 0.1, 2.8 ± 0.2, 1.3 ± 0.1, 0.9 ± 0.02, and 0.6 ± 0.16 ka. These stages correlate to each of the seven latest Holocene regional glacial stages identified across the monsoon‐influenced Himalaya, demonstrating that a coherent record of high elevation terrestrial palaeoclimate change can be extracted from dynamic mountain landscapes. The time‐constrained moraine complex represents a catchment‐wide denudation rate of 0.8–1.4 mm a−1 over the last 8 kyr. The geometry of the ablation area of Khumbu Glacier changed around 4 ka from a broad, shallow ice tongue to become narrower and thicker as restricted by the topographic barrier of the terminal moraine complex. Plain Language Summary: Satellite observations indicate that glaciers in the monsoon‐influenced Himalaya are changing rapidly in response to climate change. However, understanding why glaciers are changing requires observing glacier behavior over longer timescales using the glacial geological record. We mapped the geometry and measured the ages of ice‐marginal moraines built by two adjacent glaciers in the Everest region of Nepal. The moraines represent a complete record of glacier expansion during cold periods in the monsoon‐influenced Himalayan region over the last 8,000 years. Moraines formed by the large Khumbu Glacier and the smaller, steeper Lobuche Glacier also reveal differences in how these glaciers have changed since the last Ice Age. The results are useful to understand how monsoon‐influenced Himalayan glaciers respond to climate change, and to improve projections of their future behavior. Key Points: Ice‐marginal moraines in the upper Khumbu Valley represent a complete record of regional glacier change between 7.4 ka and the present dayMoraine building modified the response of Khumbu Glacier to climate change after 8 kaHolocene moraine volume indicates a catchment‐wide denudation rate of 0.8–1.4 mm per year [ABSTRACT FROM AUTHOR]

Glaciers fluctuate in response to climate change and record these changes by building sedimentary landforms, including moraines. Therefore, glacial landscapes are a potentially valuable archive of terrestrial palaeoclimate change. Typically, a cooling climate causes glaciers to expand and a warming climate causes glaciers to shrink. However, the glacier response time and the influence of mountainous topography on glacier dynamics complicates this behaviour, such that moraines are not always a straightforward indicator of glacier change in response to climate change. We used a glacial landscape evolution model to simulate the response of a hypothetical mountain glacier to simple changes in climate and the resulting formation and preservation of moraines. These results show that the rate of climate change relative to the glacier response time determines the geometry, number, and position of moraines. Glaciers can build distinct moraines in the absence of climate change. The distance from the maximum ice extent may not represent the chronological order of moraine formation. Moraines can be preserved after being overrun and eroded by subsequent glaciations, but moraine sequences may also contain gaps that are unidentifiable in the field. [ABSTRACT FROM AUTHOR]

Climate is currently warming due to anthropogenic impact on the Earth's atmosphere. To better understand the processes and feedbacks within the climate system that underlie this accelerating warming trend, it is useful to examine past periods of abrupt climate change that were driven by natural forcings. Glaciers provide an excellent natural laboratory for reconstructing the climate of the past as they respond sensitively to climate oscillations. Therefore, we study glacier systems and their behavior during the transition from colder to warmer climate phases, focusing on the period between 15 and 10 ka. Using a combination of geomorphological mapping and beryllium-10 surface exposure dating, we reconstruct ice extents in two glaciated valleys of the Silvretta Massif in the Austrian Alps. The mountain glacier record shows that general deglaciation after the Last Glacial Maximum (LGM) was repeatedly interrupted by glacier stabilization or readvance, perhaps during the Oldest Dryas to Bølling transition (landform age: 14.4 ± 1.0 ka) and certainly during the Younger Dryas (YD; 12.9–11.7 ka) and the Early Holocene (EH; 12–10 ka). The oldest landform age indicates a lateral ice margin that postdates the 'Gschnitz' stadial (ca. 17–16 ka) and predates the YD. It shows that local inner-alpine glaciers were more extensive until the onset of the Bølling warm phase (ca. 14.6 ka), or possibly even into the Bølling than during the subsequent YD. The second age group, ca. 80 m below the (pre-)Bølling ice margin, indicates glacier extents during the YD cold phase and captures the spatial and temporal fine structure of glacier retreat during this period. The ice surface lowered approximately 50–60 m through the YD, which is indicative of milder climate conditions at the end of the YD compared to its beginning. Finally, the third age group falls into a period of more substantial warming, the YD–EH transition, and shows discontinuous glacier retreat during the glacial to interglacial transition. The new geochronologies synthesized with pre-existing moraine records from the Silvretta Massif evidence multiple cold phases that punctuated the general post-LGM warming trend and illustrate the sensitive response of Silvretta glaciers to abrupt climate oscillations in the past. [ABSTRACT FROM AUTHOR]

Sub-Antarctic glacier chronologies can provide valuable information about the past variability of climate dynamics in the Southern Ocean region. The Kerguelen Archipelago (49°S) is advantageously located under the influence of the Southern Hemisphere's westerly wind belt, thus fluctuations of climate-sensitive glaciers on Kerguelen can provide a baseline for understanding the behavior of this atmospheric regime in response to climatic forcings. We present 17 36Cl exposure ages of moraine and erratic boulders to provide chronological constraints to paleoglacier extents of the Guynemer cirque glacier, located just north of the Cook Ice Cap. Erratic boulders show ice thinning in the Guynemer region started to occur in the Late Glacial by 13.5 ka and continued past 12.4 ka. Ice retreat was punctuated by the formation of two moraine stages, the outermost at 11.5 ± 0.4 ka followed by another at 10.4 ± 1.2 ka, which are indicative of Early Holocene glacier advances/standstills. A glacial advance occurred at 1.4 ± 0.3 ka, which corroborates other Late Holocene re-advances elsewhere on the archipelago. Finally, three undated moraine stages are found between 1.4 ka and the 1960s. The lack of moraines after 10.4 ka and through the Mid-Holocene suggests that the Guynemer glacier was significantly smaller during this extended period of the Holocene compared to its Early Holocene as well as its Late Holocene limits. The Guynemer glacier history provides unique evidence of Early Holocene moraines on Kerguelen, which have not been discovered thus far on the archipelago. Similar to glaciers in Patagonia, New Zealand and South Georgia, the Guynemer glacier was at its largest Holocene extent in the Early Holocene. However, while other southern mid-latitude glacier chronologies show progressively smaller glacial extents throughout the Mid- to Late Holocene, the Late Holocene re-advance of the Guynemer glacier, like other Kerguelen glaciers, likely exceeded its Mid-Holocene extent. • We present 17 new 36Cl surface exposure ages from the Kerguelen Archipelago. • 36Cl ages range from 13.5 ± 0.3 ka to 1.2 ± 0.2 ka. • First early Holocene-dated moraines on Kerguelen. • Glacial readvance occurred in late Holocene. • Holocene glacial evolution on Kerguelen differs from other sub-Antarctic glaciers. [ABSTRACT FROM AUTHOR]

Increasingly frequent glacier-rock avalanches (GRAs) – events triggered by the detachment of both glacier and rock materials – have occurred in recent years in the Sedongpu gully in the eastern Himalayan syntaxis, blocking the course of the Yarlung Zangbo River repeatedly. To identify spatio-temporal patterns and influencing factors of these GRAs, we analyzed remote sensing images and produced high-resolution digital surface models. At least eight GRAs, originating from the same source areas, have occurred in the past decades: one in 1974, one in 2014, and six between 2017 and 2018. The GRAs that occurred since 2014 were responsible for the loss of > 70 Mm3 of glacier and rock and > 150 Mm3 of moraine deposits and increased the elevation of the basin outlet by 60–120 m. Climate change-induced glacier retreat, steep topography, and a recent strong earthquake were found to be related to the occurrence of the recent GRAs, which resulted in the formation of a knickpoint in the Yarlung Zangbo River. [ABSTRACT FROM AUTHOR]

The timing of mountain glacier fluctuations is poorly constrained in some parts of Greenland during the Late Holocene. We present 31 10Be cosmic‐ray exposure ages (CRE) of boulders collected from three mountain glacier moraines located in the Tasilap valley, in southeastern Greenland, and 10 10Be CRE ages from one mountain glacier in the Isortup valley, in southern Greenland. For the first time in these areas, mountain glacier fluctuations are documented from moraine CRE for the Late Holocene period. Several glacier advances during the Late Holocene are revealed with exposure ages ranging from 3.90±0.26 to 0.4±0.04 ka. Moraines of three of the four glaciers investigated, dated to 3.75±0.13 ka (n = 3), 3.3±0.19 ka (n = 2) and 2.87±0.13 ka (n = 3), show a common timing of the largest glacier expansion during the Late Holocene. Evidence of at least one individual moraine deposited at ~1.2 ka was found on all glaciers. Finally, the most recent period of glacial advance during the Late Holocene is documented by one glacier in each valley at ~0.66–0.70 ka. The maximum glacier extent at ~3 ka differs from the Late Holocene glacier maximum extent usually reported during the Little Ice Age in east Greenland based on moraine dating and lake sediments. We suggest that the combination of a stronger East Greenland Current and a weaker Irminger Current, potentially associated with increased sea‐ice concentration, superimposed on the long‐term decrease in summer insolation during the Late Holocene could be responsible for this large glacial advance at ~3 ka in southern and southeastern Greenland. [ABSTRACT FROM AUTHOR]

Topographic development via paraglacial slope failure (PSF) represents a complex interplay between geological structure, climate, and glacial denudation. Southeastern Tibet has experienced amongst the highest rates of ice mass loss in High Mountain Asia in recent decades, but few studies have focused on the implications of this mass loss on the stability of paraglacial slopes. We used repeat satellite- and unpiloted aerial vehicle (UAV)-derived imagery between 1990 and 2020 as the basis for mapping PSFs from slopes adjacent to Hailuogou Glacier (HLG), a 5 km long monsoon temperate valley glacier in the Mt. Gongga region. We observed recent lowering of the glacier tongue surface at rates of up to 0.88 m a -1 in the period 2000 to 2016, whilst overall paraglacial bare ground area (PBGA) on glacier-adjacent slopes increased from 0.31 ± 0.27 km 2 in 1990 to 1.38 ± 0.06 km 2 in 2020. Decadal PBGA expansion rates were ∼ 0.01 km 2 a -1 , 0.02 km 2 a -1 , and 0.08 km 2 in the periods 1990–2000, 2000–2011, and 2011–2020 respectively, indicating an increasing rate of expansion of PBGA. Three types of PSFs, including rockfalls, sediment-mantled slope slides, and headward gully erosion, were mapped, with a total area of 0.75 ± 0.03 km 2 in 2020. South-facing valley slopes (true left of the glacier) exhibited more destabilization (56 % of the total PSF area) than north-facing (true right) valley slopes (44 % of the total PSF area). Deformation of sediment-mantled moraine slopes (mean 1.65–2.63 ± 0.04 cm d -1) and an increase in erosion activity in ice-marginal tributary valleys caused by a drop in local base level (gully headward erosion rates are 0.76–3.39 cm d -1) have occurred in tandem with recent glacier downwasting. We also observe deformation of glacier ice, possibly driven by destabilization of lateral moraine, as has been reported in other deglaciating mountain glacier catchments. The formation, evolution, and future trajectory of PSFs at HLG (as well as other monsoon-dominated deglaciating mountain areas) are related to glacial history, including recent rapid downwasting leading to the exposure of steep, unstable bedrock and moraine slopes, and climatic conditions that promote slope instability, such as very high seasonal precipitation and seasonal temperature fluctuations that are conducive to freeze–thaw and ice segregation processes. [ABSTRACT FROM AUTHOR]

With the retraction of glaciers in maritime Antártica, and the climate change scenarios, it is necessary to understand the geomorphological processes at work in these recently exposed areas. The purpose of the article is to present the Geomorphon Method for Antártica (Geomorphon Method Revised to Antártica-gma) applied to the mapping of landforms in the ice-free areas of King George Island. The classification evaluation was carried out based on the interpretation of the mde and on the field work carried out in 2015 and 2016. The relief elements identified by the gma were related to the erosive and depositional forms of the glacial genesis macro scale, as valleys, aretes, horns and meso-scale, such as glaciofluvial channels, moraines of advance and recession, and even those of paraglacial and marine genesis. Frontal advancing moraines were identified in all areas, except for the Ecology glacier paraglacial system, and together with the mapped u-valleys, they indicate the old direction of flow of the glaciers, and places where there was greater thickness of ice. The identification of these forms contributes to studies that evaluate the succession of changes in the landscape with the recent retraction of glacial systems, proving the potential of gma. [ABSTRACT FROM AUTHOR]

The young moraine area to the south-east of Berlin was repeatedly overrun and covered by Scandinavian ice sheets (SISs). The last glaciation took place during the Last Glacial Maximum (LGM), when the last/most recent SIS reached its furthest southern extent. An incompletely formed chain of terminal moraines marks the Brandenburg ice stage. The most recent glacier had its greatest environmental impact due to the large quantities of released meltwaters. Many subglacial channels, massive proglacial sands and huge meltwater streamways (Urstromtäler) were formed at that time. During the Holocene, the landscape was finally shaped mainly by the rivers Dahme and Spree. [ABSTRACT FROM AUTHOR]

The Upper Garonne Basin included the largest glacial system in the Pyrenees during the last glacial cycle. Within the long‐term glacial retreat during Termination‐1 (T‐1), glacier fluctuations left geomorphic evidence in the area. However, the chronology of T‐1 glacial oscillations on the northern slopes of the Central Pyrenees is still poorly constrained. Here, we introduce new geomorphological observations and a 12‐sample dataset of 10Be cosmic‐ray exposure ages from the Ruda Valley. This U‐shaped valley, surrounded by peaks exceeding 2800 m a.s.l., includes a sequence of moraines and polished surfaces that enabled a reconstruction of the chronology of the last deglaciation. Following the maximum ice extent, warmer conditions prevailing at ~15–14 ka, during the Bølling–Allerød (B–A) Interstadial, favoured glacial retreat in the Ruda Valley. Within the B–A, glaciers experienced two phases of advance/stillstand with moraine formation at 13.5 and 13.0 ka. During the early Younger Dryas (YD), glacial retreat exposed the highest surfaces of the Saboredo Cirque (~2300–2350 m) at 12.7 ka. Small glaciers persisted only inside the highest cirques (~2470 m), such as in Sendrosa Cirque, with moraines stabilising at 12.6 ka. The results of this work present the most complete chronology for Pyrenean glacial oscillations from the B–A to the YD. [ABSTRACT FROM AUTHOR]

The Upper Garonne Basin included the longest glacier in the Pyrenees during the Late Pleistocene. During major glacial advances, the Garonne palaeoglacier flowed northwards along ~ 80 km from peaks of the axial Pyrenees exceeding 2800–3000 m until the foreland of this mountain range at the Loures–Barousse–Barbazan basin (LBBb), at 420–440 m. Here, the palaeoglacier formed a terminal moraine complex that is examined in this work. Based on geomorphological observations and a 12-sample data set of 10Be Cosmic-Ray Exposure (CRE) ages, the timing of the maximum glacial extent was constrained as well as the onset of the deglaciation from the end of the Last Glacial Cycle (LGC). Chronological data shows evidence that the external moraines in this basin were abandoned by the ice at the end of the Penultimate Glacial Cycle (PGC) and the onset of the Eemian Interglacial, at ~ 129 ka. No evidence of subsequent glacial advances or standstills occurred during the LGC in this basin were found, as the few existing datable boulders provided in the internal moraine showed inconsistent ages, thus probably being affected by post-glacial processes. The terminal basin was already deglaciated during the global Last Glacial Maximum at 24–21 ka, as revealed by exposure ages of polished surfaces at the confluence of the Garonne-La Pique valleys, 13 km south of the entrance of the LBBb. This study introduces the first CRE ages in the Pyrenees for the glacial advance occurred during the PGC and provides also new evidence that glaciers had already significantly shrunk during the LGM. [ABSTRACT FROM AUTHOR]

Glaciers preserve climate variations in their geological and geomorphological records, which makes them prime candidates for climate reconstructions. Investigating the glacier–climate system over the past millennia is particularly relevant first because the amplitude and frequency of natural climate variability during the Holocene provides the climatic context against which modern, human-induced climate change must be assessed. Second, the transition from the last glacial to the current interglacial promises important insights into the climate system during warming, which is of particular interest with respect to ongoing climate change. Evidence of stable ice margin positions that record cooling during the past 12 kyr are preserved in two glaciated valleys of the Silvretta Massif in the eastern European Alps, the Jamtal (JAM) and the Laraintal (LAR). We mapped and dated moraines in these catchments including historical ridges using beryllium-10 surface exposure dating (10 Be SED) techniques and correlate resulting moraine formation intervals with climate proxy records to evaluate the spatial and temporal scale of these cold phases. The new geochronologies indicate the formation of moraines during the early Holocene (EH), ca. 11.0 ± 0.7 ka (n = 19). Boulder ages along historical moraines (n = 6) suggest at least two glacier advances during the Little Ice Age (LIA; ca. 1250–1850 CE) around 1300 CE and in the second half of the 18th century. An earlier advance to the same position may have occurred around 500 CE. The Jamtal and Laraintal moraine chronologies provide evidence that millennial-scale EH warming was superimposed by centennial-scale cooling. The timing of EH moraine formation coincides with brief temperature drops identified in local and regional paleoproxy records, most prominently with the Preboreal Oscillation (PBO) and is consistent with moraine deposition in other catchments in the European Alps and in the Arctic region. This consistency points to cooling beyond the local scale and therefore a regional or even hemispheric climate driver. Freshwater input sourced from the Laurentide Ice Sheet (LIS), which changed circulation patterns in the North Atlantic, is a plausible explanation for EH cooling and moraine formation in the Nordic region and in Europe. [ABSTRACT FROM AUTHOR]

The Cook Ice Cap (CIC) on the sub-Antarctic Kerguelen Islands recently experienced extremely negative surface mass balance. Further deglaciation could have important impacts on endemic and invasive fauna and flora. To put this exceptional glacier evolution into a multi-centennial-scale context, we refined the evolution of the CIC over the last millennium, investigated the associated climate conditions and explored its potential evolution by 2100 ce. A glaciological model, constrained by cosmic ray exposure dating of moraines, historical documents and recent direct mass balance observations, was used to simulate the ice-cap extents during different phases of advance and retreat between the last millennium and 2100 ce. Cosmogenic dating suggests glacial advance around the early Little Ice Age (LIA), consistent with findings from other sub-Antarctic studies, and the rather cold and humid conditions brought about by the negative phase of the Southern Annular Mode (SAM). This study contributes to our currently limited understanding of palaeoclimate for the early LIA in the southern Indian Ocean. Glaciological modelling and observations confirm the recent decrease in CIC extent linked to the intensification of the SAM. Although affected by large uncertainties, future simulations suggest a complete disappearance of CIC by the end of the century. [ABSTRACT FROM AUTHOR]

Robustly-dated glacial landforms provide us a means of examining millennial-scale climate events during the late-glacial period, which could shed new light on the bipolar seesaw hypothesis. Although many moraines are proposed to be late-glacial in age across the Himalayas, the well-determined late-glacial moraine sequences remain extremely rare in the central Himalaya (e.g. the Paiku Gangri area). The paucity of high-precision chronologies limits our ability to fully explore the response of Himalayan glaciers to late-glacial climate reversals. Here, we present a detailed geomorphic map of glaciers in the Laqu River Valley, northwest of Mt. Gang Benchhen and a10Be-based moraine chronology from 24 boulders from the late-glacial period. The dating results indicate that glaciers in the studied catchment reached their maximum late-glacial extent about 16.1 ka ago, prior to the Younger Dryas Stadial (YDS), and that a following glacial culmination occurred at 12.2 ± 0.9 ka, corresponding roughly to the YDS. The emerging pattern of glacial fluctuations is similar at local, regional, and global scales, suggesting a interhemispheric coherency of late-glacial glacier behaviors. The Analysis of dynamic response of Himalayan glaciers to climate change suggests a temperature-sensitive mountain-glacier system, supporting the view that the bipolar seesaw was primarily a northern winter phenomenon during the late-glacial interval. [ABSTRACT FROM AUTHOR]