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Despite numerous studies on Himalayan erosion, it is not known how the very high Himalayan peaks erode. Although valley floors are efficiently eroded by glaciers, the intensity of periglacial processes, which erode the headwalls extending from glacial cirques to crest lines, seems to decrease sharply with altitude 1 , 2 . This contrast suggests that erosion is muted and much lower than regional rock uplift rates for the highest Himalayan peaks, raising questions about their long-term evolution 3 , 4 . Here we report geological evidence for a giant rockslide that occurred around 1190  ad in the Annapurna massif (central Nepal), involving a total rock volume of about 23 km 3 . This event collapsed a palaeo-summit, probably culminating above 8,000 m in altitude. Our data suggest that a mode of high-altitude erosion could be mega-rockslides, leading to the sudden reduction of ridge-crest elevation by several hundred metres and ultimately preventing the disproportionate growth of the Himalayan peaks. This erosion mode, associated with steep slopes and high relief, arises from a greater mechanical strength of the peak substratum, probably because of the presence of permafrost at high altitude. Giant rockslides also have implications for landscape evolution and natural hazards: the massive supply of finely crushed sediments can fill valleys more than 150 km farther downstream and overwhelm the sediment load in Himalayan rivers for a century or more. Observations and samples from the central Himalayas show that a giant rockslide occurring around 1190 ad in the Annapurna massif led to the collapse of an elevated palaeo-summit, illustrating the episodic mode of erosion of the glaciated high relief by mega-rockslides.

In the European Alps, almost half the glacier volume has disappeared over the past 150 years. The loss is reflected in glacier retreat and ice surface lowering even at high altitude. In steep glacial cirques, surface lowering exposes rock to atmospheric conditions probably for the very first time in several millennia. Instability of rockwalls has long been identified as one of the direct consequences of deglaciation, but so far cirque-wide quantification of rockfall at high resolution is missing. Based on terrestrial lidar, a rockfall inventory for the permafrost-affected rockwalls of two rapidly deglaciating cirques in the Central Alps of Austria (Kitzsteinhorn) is established. Over 6 years (2011–2017), 78 rockwall scans were acquired to generate data of high spatial and temporal resolution. Overall, 632 rockfalls were registered, ranging from 0.003 to 879.4 m3, mainly originating from pre-existing structural rock weaknesses. A total of 60 % of the rockfall volume detached from less than 10 vertical metres above the glacier surface, indicating enhanced rockfall activity over tens of years following deglaciation. Debuttressing seems to play a minor effect only. Rather, preconditioning is assumed to start inside the randkluft (void between cirque wall and glacier) where measured sustained freezing and ample supply of liquid water likely cause enhanced physical weathering and high quarrying stresses. Following deglaciation, pronounced thermomechanical strain is induced and an active layer penetrates into the formerly perennially frozen bedrock. These factors likely cause the observed paraglacial rockfall increase close to the glacier surface. This paper, the first of two companion pieces, presents the most extensive dataset of high-alpine rockfall to date and the first systematic documentation of a cirque-wide erosion response of glaciated rockwalls to recent climate warming.

There are no large glaciers in the territory of Bulgaria, but small patches of snow and firn have been observed in the high mountains at the end of summer. Perennial snow patches and microglaciers are considered indicators of permafrost occurrence. The results from the first detailed geophysical investigations of the Snezhnika glacieret, considered to be the southernmost microglacier in Europe, situated in the Golyam Kazan cirque, Pirin Mountains, Bulgaria, are presented in the paper. Ground-penetrating radar (GPR) and 2D electrical resistivity tomography (ERT) were used to estimate the thickness of the microglacier as well as its subsurface structure. Measurements started in 2018 and continued over the next 2 years in order to assess changes in its size and thickness. The mean thickness of Snezhnika is about 4–6 m, reaching 8 m or probably more in some areas. ERT measurements of the deeper parts of the microglacier beds show high electrical resistivities reaching over 60 000 Ωm at a depth of 4–10 m. An anomaly at this depth is likewise distinguishable on the GPR profiles. These anomalies are interpreted as permafrost areas and were consistently observed on the ERT and GPR profiles in the 2 years of the study. These results imply for the first time the existence of permafrost in the Pirin Mountains and in Bulgaria.

Betting on the most promising new ideas is key to creativity and innovation in organizations, but predicting the success of novel ideas can be difficult. To select the best ideas, creators and managers must excel at creative forecasting, the skill of predicting the outcomes of new ideas. Using both a field study of 339 professionals in the circus arts industry and a lab experiment, I examine the conditions for accurate creative forecasting, focusing on the effect of creators' and managers' roles. In the field study, creators and managers forecasted the success of new circus acts with audiences, and the accuracy of these forecasts was assessed using data from 13,248 audience members. Results suggest that creators were more accurate than managers when forecasting about others' novel ideas, but not their own. This advantage over managers was undermined when creators previously had poor ideas that were successful in the marketplace anyway. Results from the lab experiment show that creators' advantage over managers in predicting success may be tied to the emphasis on both divergent thinking (idea generation) and convergent thinking (idea evaluation) in the creator role, while the manager role emphasizes only convergent thinking. These studies highlight that creative forecasting is a critical bridge linking creativity and innovation, shed light on the importance of roles in creative forecasting, and advance theory on why creative success is difficult to sustain over time.

Groundwater storage in alpine regions is essential for maintaining baseflows in mountain streams. Recent studies have shown that common alpine landforms (e.g., talus and moraine) have substantial groundwater storage capacity, but the hydrogeological connectivity between individual landforms has not been understood. This study characterizes the hydrogeology of an alpine cirque basin in the Canadian Rocky Mountains that contains typical alpine landforms (talus, meadow, moraines) and hydrological features (tarn, streams, and springs). Geological, hydrological, and hydrochemical observations were used to understand the overall hydrogeological setting of the study basin, and three different geophysical methods (electrical resistivity tomography, seismic refraction tomography, and ground penetrating radar) were used to characterize the subsurface structure and connectivity, and to develop a hydrogeological conceptual model. Geophysical imaging shows that the talus is typically 20–40 m thick and highly heterogeneous. The meadow sediments are only up to 11 m thick but are part of a 30–40-m-thick accumulation of unconsolidated material that fills a bedrock overdeepening (i.e. a closed, subglacial basin). A minor, shallow groundwater system feeds springs on the talus and streams on the meadow, whereas a deep system in the moraine supplies most of the water to the basin outlet springs, thereby serving as a ‘gate keeper’ of the basin. Although the hydrologic functions of the talus in this study are substantially different from other locations, primarily due to differences in bedrock lithology and geomorphic processes, the general conceptual framework developed in this study is expected to be applicable to other alpine regions.

Cirques, as typical representatives of glacial erosion landforms, serve as important indicators for reconstructing paleoclimate and paleoenvironments. Current research on cirque morphology in the western Kunlun Mountains remains limited, hindering a comprehensive understanding of cirques in this region. This study focuses on the western Kunlun Mountains in the Tibetan Plateau, extracting morphological parameters (length L, width W, height H, area Area, floor elevation E-min, etc.) of 75 cirques based on high-resolution remote sensing imagery. The results indicate a coordinated growth of morphological parameters during cirque development, with the highest proportion of cirques facing northeast (NE). The distribution of cirque orientations is relatively concentrated, and cirques at higher altitudes tend to be larger in size. This research fills a gap in the study of cirques in the western Kunlun Mountains and provides new insights for paleoclimate reconstruction in the region.

We present a field-based reconstruction of the geomorphology in the Subtropical Andean mountains of the Limarí basin, semiarid central Chile (30-31° S). Fieldwork campaigns and remote-sensing analysis served for detailed geomorphological mapping at four formerly glaciated valleys in the heads of the Combarbalá and Río Hurtado sub-basins. We identify a mosaic of glacial, periglacial, and paraglacial landforms. Glacial landforms include a massive dead-ice moraine complex, with thermokarst and debris-filled fractures suggesting former ice-cored moraine degradation. This landform is superimposed by transversal and arcuate ridges suggesting active-ice processes. Periglacial landforms such as rock glaciers, gelifluction, and protalus lobes occur in cirques and U-shaped valleys, but also on moraine deposits. Paraglacial processes are indicated by talus accumulation in those formerly glaciated slopes. The geomorphological imprint is evidence for the interaction and succession between glacial, periglacial, and paraglacial dynamics from the Late Pleistocene to the present.

Geomorphological mapping of glaciers and glacial landforms helps describe the current environment and investigate past glacial changes. Here we present the first detailed 1:80,000 glacial geomorphological map of the Vanch River basin (about 2100 km 2 ), the western Pamirs, Tajikistan [38.6667°N, 72.0000°E]. Mapping was performed using DEM (30 m), Landsat 8 imagery (15 m), and Google Earth images (∼1 m). The resultant map provides the spatial distribution of glaciers and associated erosional and depositional landforms such as cirques, glacial valleys, rock glaciers, and moraines. Morphology of the lower section of the main valley outlines the limits of Vanch Glacier in the Middle Pleistocene. Comparison with former glacier inventories indicates that the glaciers have generally been stable, but the proportion of debris-covered areas has increased since 2007. The identified 184 intact rock glaciers represent hidden water storage, providing a new basis for estimating water resources in the basin.

1. Carbon storage in vegetation and soil underpins climate regulation through carbon sequestration. Because plant species differ in their ability to capture, store and release carbon, the collective functional characteristics of plant communities (functional diversity) should be a major driver of carbon accumulation in terrestrial ecosystems. 2. Three major components of plant functional diversity could be put forward as drivers of carbon storage in ecosystems: the most abundant functional trait values, the variety of functional trait values and the abundance of particular species that could have additional effects not incorporated in the first two components. 3. We tested for associations between these components and carbon storage across 16 sites in the Chaco forest of Argentina under the same climate and on highly similar parental material. The sites differed in their plant functional diversity caused by different long-term land-use regimes. 4. We measured six plant functional traits in 27 species and weighted them by the species abundance at each site to calculate the community-weighted mean (CWM) and the functional divergence (FDvar) of each single trait and of multiple traits (FDiv). We also measured plant and soil carbon storage. Using a stepwise multiple regression analysis, we assessed which of the functional diversity components best explained carbon storage. 5. Both CWM and FDvar of plant height and wood-specific gravity, but no leaf traits, were retained as predictors of carbon storage in multiple models. Relationships of FDvar of stem traits and FDiv with carbon storage were all negative. The abundance of five species improved the predictive power of some of the carbon storage models. 6. Synthesis. All three major components of plant functional diversity contributed to explain carbon storage. What matters the most to carbon storage in these ecosystems is the relative abundance of plants with tall, and to a lesser extent dense, stems with a narrow range of variation around these values. No consistent link was found between carbon storage and the leaf traits usually associated with plant resource use strategy. The negative association of trait divergence with carbon storage provided no evidence in support to niche complementarity promoting carbon storage in these forest ecosystems.