Glacier Stages Research Articles

Timing and extent of glaciation since the Last Glacial Maximum in the upper Kalguty basin, Russian Altai Mountains

ABSTRACTThe mountains systems of Central Asia are primary targets to study late Pleistocene climate evolution given their location at the crossroads of several atmospheric circulation systems. The timing of glacier extent during this period remains understudied, especially in the Altai Mountains. Here, we have reconstructed glacier extent during three main Late Pleistocene stadials in the upper Kalguty basin (south‐eastern Russian Altai) based on field‐based geomorphic analysis. Additionally, surface exposure dating with 10Be and 26Al at a key site was used to infer a minimum‐limiting age for the outermost well‐preserved Pleistocene frontal moraine system and to date the inception of glacier withdrawal. According to our data, around 20.6 ± 1.8 ka Kalguty Glacier was still 200 m thick at the key site, 10 km upstream of the outermost moraine, and the site was totally deglaciated shortly after 20.4 ± 0.4 ka. These results point to a rapid retreat of this low‐gradient valley glacier after its probably MIS 2 maximum which was prior to 21 ka and probably prior to 22.5 ka. Two other glacier stages have been identified upvalley, characterized by a depression of the equilibrium‐line altitude of 420 and 314 m with respect to the Little Ice Age, thus corresponding to Lateglacial advances. Our glacier reconstruction further provides a geomorphological and geochronological background to put into context archaeological findings in this area.

Geoheritage of East Kazakhstan

East Kazakhstan is physiographically a diverse region of north-central Asia encompassing a broad array of geomorphic zones and geo-ecosystems from the western open steppes to the interior arid basins with wind-sculptured surfaces of the surrounding rocky highlands aligned by the high alpine mountain ranges. The complex regional geological history gave rise to a mosaic of impressive landforms located within a relatively small area. The extraordinary relief with many unique geo-sites was generated by dynamic processes associated with the late Cainozoic orogenesis in conjunction with the past climatic variations. The cyclicity of bedrock weathering and mass sediment transfer are manifested by Mesozoic fossiliferous formations, large sand dune fields, and loess-palaeosol-cryogenic series providing archives of the Quaternary evolution. Pleistocene glaciations followed by cataclysmic floods from the released ice-dammed lakes during the recessional glacier stages have produced an exceptional imprint in the mountain areas. Many archaeological localities and historic monuments, some being a part of the UNESCO World Natural and Cultural Heritage, are associated with the most prominent topographic places. Geo-tourism focusing on the most exquisite landscapes and spectacular geological settings is the new trend in the country with still minor activities that take advantage of the region’s supreme geoheritage potential. The great geo-diversity accentuates the touristic value of this still marginally explored geographic area. Reconnaissance, documentation, and publicity of the most unique geo-sites and geo-parks provide an impetus for their registration in the national and international nature heritage protection programs under proper geo-environmental conservation policies.

Lateglacial and Early Holocene glacier stages - New dating evidence from the Meiental in central Switzerland

In order to improve our understanding of the glacier development in central Switzerland after the Last Glacial Maximum (LGM) we have investigated moraine sequences of the Meiental (“Meien Valley”). After detailed field mapping, 34 rock samples from different moraines were dated with cosmogenic 10Be. The results indicate that the investigated moraines were deposited mainly in multi-phased advances during the Younger Dryas and the Early Holocene. This is in contrast to previous studies suggesting that these moraines represent equivalents of the older Egesen and Daun stadials. Our research shows that factors like the moraine stratigraphy, geomorphologic characteristics and Equilibrium Line Altitudes (ELAs) can be highly variable at the local scale, which can make a stadial correlation of moraines between different valleys or regions within the Alps without age constraints ambiguous and unreliable. Against this background the interregional use of ΔELAs (ELA depressions) for the parallelization of paleo-glacier extents throughout the Alps according to traditional concepts of the Lateglacial deglaciation seems to produce erroneous results. Geomorphologic observations and relative age relationships in moraine successions based on stratigraphic principles remain the basis for this kind of studies. But as we show here it is necessary to base local-to-regional comparisons of moraine sequences additionally on exposure ages to gain a more reliable understanding of the Alpine glacier development after the LGM.

A modelling approach to reconstruct Little Ice Age climate from remote-sensing glacier observations in southeastern Tibet

AbstractWe use numerical modelling of glacier mass balance combined with recent and past glacier extents to obtain information on Little Ice Age (LIA) climate in southeastern Tibet. We choose two glaciers that have been analysed in a previous study of equilibrium-line altitudes (ELA) and LIA glacier advances with remote-sensing approaches. We apply a physically based surface energy- and mass-balance model that is forced by dynamically downscaled global analysis data. The model is applied to two glacier stages mapped from satellite imagery, modern (1999) and LIA. Precipitation scaling factors (PSF) and air temperature offsets (ATO) are applied to reproduce recent ELA and glacier mass balance (MB) during the LIA. A sensitivity analysis is performed by applying seasonally varying gradients of precipitation and air temperature. The calculated glacier-wide MB estimate for the period 2000–12 is negative for both glaciers (–992±366 kgm–2 a–1 and –1053±258 kgm–2 a–1). Relating recent and LIA PSF/ATO sets suggests a LIA climate with ~8–25% increased precipitation and ~1–2.5°C lower mean air temperature than in the period 2000–12. The results only provide an order of magnitude because deviations in other input parameters are not considered.

Lateglacial studies in the western valleys of the Italian Julian Alps and in the Koritnica valley

Different from the northern valleys of the Italian Julian Alps the bottoms of the western valleys do not contain any late-pleistocene moraines. However, common to all valleys is the large glaciation most probably in the Gschnitz-stage, in which the glaciers reached particularly low locations due to special favourable aspects such as north-exposure, steep and narrow gorges, high shading and considerable snow accumulation. This is also valid for the sidebranches of the Slovenian Koritnica valley which are again directed west-east. Still younger glacier stages could be found in the upper sections of the Dogna, Raccolana and Bala valley. For the moraines of very low altitudes in the Resia valley, at the entrance to Možnica and the upper Raccolana valley pollen analyses are available. All considerations in the paper are estimations based on geomorphological and climatological experience.

Historical (

Historical (<1700 B.P.) to neoglacial (5500-1700 B.P.) glacier stages in the Inner Himalaya (north of the Annapurna- and Dhaulagiri-Himalaya) (28°39'-58’N/83°28’-58’E)

Geomorphology of anomalously high glaciated mountains at the northwestern end of Tibet: Muztag Ata and Kongur Shan

Muztag Ata and Kongur Shan massifs represent a significant area of anomalously high topography at the northwestern end of the Tibetan Plateau, rising to > 7500 m above sea-level (asl) from the plateau that has an average elevation of ~ 3500 m asl. These massifs provide an excellent opportunity to test geomorphic concepts, such as the glacial buzz-saw model. Using remote sensing, digital elevation modeling, field mapping and terrestrial cosmogenic nuclide (TCN) methods, the massifs were examined to determine the relative importance of tectonics and geomorphic processes in shaping the regional landscape and to provide a framework for testing geomorphic models. The gneiss domes that underlie the peaks are the result of exhumation along the Kongur detachment fault that has unroofed the massifs at a rate of between 4–6 km/Ma over the last few million years. This has resulted in rapid uplift and active seismicity, which is exemplified by the numerous fresh fault scarps throughout the region and large historic earthquakes. The geomorphic system is dominated by glaciation and the region contains extensive successions of moraines and paraglacial landforms, including fans, terraces and landslides. Glaciers have oscillated considerably throughout the latter part of the Quaternary, and three major glacier stages are recognized (Karasu [oldest], Olimde and Subaxh [youngest] glacial stage) that include at least 10 smaller glacial advance. The style of glaciation has changed over time from expanded ice caps to piedmont glaciers to valley and cirque glaciers. This possibly reflects a change in climate and/or topographic constraints as the massifs grew and became incised. The topography and glaciers in the region vary across the massifs divided by a broadly N–S trending high ridge and watershed. The western portion, situated upwind (the stoss slopes) of the mid-latitude westerlies, that bring moisture to the region, has gentle high topography and small valley glaciers. In contrast, on the eastern leeward slopes, gradients are higher and long debris-covered valley glaciers are present. The hypsometry of the region indicate two peaks in the distribution frequency of elevation (3600–4100 m and 4400–4800 m asl). These two elevation zones are consistent in space with the former equilibrium-line altitudes during the Olimde and Subaxh glacial stages and suggest that glacial erosion (most effective at the ELA) has helped control topography. This observation supports the glacial buzz-saw hypothesis, which argues that glaciers determine hypsometry by means of rapid surface erosion. Based on TCN methods, basin-wide rates of erosion range from ~ 0.1 to 1.4 km/Ma and are five to ten times lower than the unroofing rate of both massifs. The discrepancy over different time scales suggests that initial unroofing was produced by abrupt tectonic uplift and that the unroofing of the massifs has continued at a slower pace during the Late Quaternary.

Post-sedimentary transformation of lateral moraines

The Kviarjokull, a southern outlet glacier of the Vatnajokull, is confined in the mountain foreland by lateral moraines measuring a height of up to 150 in. Each of the lateral moraines shows considerable breaches with deviations of the main moraine ridges. The paper discusses the possible origins of these modifications of the lateral moraines as result of: 1) ice overlappings during glacier advances and subsequent breaches of the lateral moraine, 2) bifurcations of the Kviarjokull glacier tongue triggered by the preglacial relief conditions and the prehistorical moraine landscape leading to afflux conditions, 3) drainage of ice-marginal glacier lakes and 4. volcanic activities, such as lava flows and volcanic-induced jokulhlaups. A historic-genetic model of the formation of the lateral moraines is presented considering the breaches in the lateral moraines as result from glacier bifurcations and therefore as former tributary tongue basins. Such breaches in the lateral moraines are also common landscape features at glaciers outside of Iceland and are from wider importance for the paleoreconstruction of former glacier stages. The knowledge of their development is essential for an adequate relative age classification of individual moraine ridges. In regard to the origin of the debris supply areas of the large-sized Kviarjokull moraines, the resedimentation of prehistoric till deposits by younger glacier advances plays a role in the formation of the lateral moraines apart from englacial and supraglacial sediment transfer processes.

Cirque glacier activity in arctic Norway during the last deglaciation

Numerous cirques of the Lofoten–Vesterålen archipelago in northern Norway have distinct moraine sequences that previously have been assigned to the Allerød-Younger Dryas (∼ 13,400 to 11,700 yr BP) interval, constraining the regional distribution of the equilibrium-line altitude (ELA) of cirque and valley glaciers. Here we present evidence from a once glacier-fed lake on southern Andøya that contests this view. Analyses of radiocarbon dated lacustrine sediments including rock magnetic parameters, grain size, organic matter, dry bulk density and visual interpretation suggest that no glacier was present in the low-lying cirque during the Younger Dryas-Allerød. The initiation of the glacial retreat commenced with the onset of the Bølling warming (∼ 14,700 yr BP) and was completed by the onset of Allerød Interstade (∼ 13,400 yr BP). The reconstructed glacier stages of the investigated cirque coincide with a cool and dry period from ∼ 17,500 to 14,700 yr BP and a somewhat larger Last Glacial Maximum (LGM) advance possibly occurring between ∼ 21,050 and 19,100 yr BP.

Reconstruction of the ice age glaciation in the southern slopes of Mt. Everest, Cho Oyu, Lhotse and Makalu (Himalaya) (part 2)

In the Khumbu-and Khumbakarna Himalaya an ice stream network and valley glacier system has been reconstructed for the last glacial period (Wurmian, Last Ice Age, Isotope stage 4–2, 60–18 Ka BP, Stage 0) with glaciogeomorphological and sedimentological methods. It was a part of the glacier system of the Himalaya and has communicated across transfluence passes with the neighbouring ice stream networks toward the W and E. The ice stream network has also received inflow from the N, from a Tibetan ice stream network, by the Kyetrak-Nangpa-Bote Koshi Drangka (Valley) in the W, by the W-Rongbuk glacier valley into the Ngozumpa Drangka (Valley), by the Central Rongbuk glacier valley into the Khumbu Drangka (Valley) and by the antecedent Arun Nadi transverse-valley in the E of the investigation area. The ice thickness of the valley glacier sections, the surface of which was situated above the snow-line, amounted to 1000–1450 m. The most extended parent valley glaciers have been measured a:rox. 70 km in length (Dudh Koshi glacier), 67 km (Barun-Arun glacier) and 80 km (Arun glacier). The tongue end of the Arun glacier has flowed down to c. 500 m and that of the Dudh Koshi glacier to c. 900 m asl. At heights of the catchment areas of 8481 (or 8475) m (Makalu), i.e., 8848 (or 8872) m (Mt. Everest, Sagarmatha, Chogolungma) this is a vertical distance of the Ice Age glaciation of c. 8000 m. The steep faces towering up to 2000 m above the neve areas of the 6000–7000 m-high surfaces of the ice stream network were located 2000–5000 m above the ELA. Accordingly, their temperatures were so low, that their rock surfaces were free of flank ice and ice balconies. From the maximum past glacier extension up to the current glacier margins, 13 (altogether 14) glacier stages have been differentiated and in part 14C-dated. They were four glacier stages of the late glacial period, three of the neoglacial period and six of the historical period. By means of 130 medium-sized valley glaciers the corresponding ELA-depressions have been calculated in comparison with the current courses of the orographic snow-line. The number of the glacier stages since the maximum glaciation a:rox. agrees with that e.g. in the Alps and the Rocky Mountains since the last glacial period. Accordingly, it is interpreted as an indication of the Wurmian age (last glacial period) of the lowest ice margin positions. The current climatic, average glacier snow-line in the research area runs about 5500 m asl. The snow-line depression (ELA) of the last glacial period (Wurm) calculated by four methods has run about 3870 m asl, so that an ELA-depression of c. 1630 m has been determined. This corresponds to a lowering of the annual temperature by c. 8, i.e.,10°C according to the specific humid conditions at that time.

Reconstruction of the Ice Age glaciation in the southern slopes of Mt. Everest, Cho Oyu, Lhotse and Makalu (Himalaya) (Part 1)

In the Khumbu-and Khumbakarna Himalaya an ice stream network and valley glacier system has been reconstructed for the last glacial period (Wurmian, Last Ice Age, Isotope stage 4–2, 60–18 Ka BP, Stage 0) with glaciogeomorphological and sedimentological methods. It was a part of the glacier system of the Himalaya and has communicated across transfluence passes with the neighbouring ice stream networks toward the W and E. The ice stream network has also received inflow from the N, from a Tibetan ice stream network, by the Kyetrak-Nangpa-Bote Koshi Drangka (Valley) in the W, by the W-Rongbuk glacier valley into the Ngozumpa Drangka (Valley), by the Central Rongbuk glacier valley into the Khumbu Drangka (Valley) and by the antecedent Arun Nadi transverse-valley in the E of the investigation area. The ice thickness of the valley glacier sections, the surface of which was situated above the snow-line, amounted to 1000–1450 m. The most extended parent valley glaciers have been measured approx. 70 km in length (Dudh Koshi glacier), 67 km (Barun-Arun glacier) and 80 km (Arun glacier). The tongue end of the Arun glacier has flowed down to c. 500 m and that of the Dudh Koshi glacier to c. 900 m asl. At heights of the catchment areas of 8481 (or 8475) m (Makalu), i.e., 8848 (or 8872) m (Mt. Everest, Sagarmatha, Chogolungma) this is a vertical distance of the Ice Age glaciation of c. 8000 m. The steep faces towering up to 2000 m above the neve areas of the 6000–7000 m-high surfaces of the ice stream network were located 2000–5000 m above the ELA. Accordingly, their temperatures were so low, that their rock surfaces were free of flank ice and ice balconies. From the maximum past glacier extension up to the current glacier margins, 13 (altogether 14) glacier stages have been differentiated and in part 14C-dated. They were four glacier stages of the late glacial period, three of the neoglacial period and six of the historical period. By means of 130 medium-sized valley glaciers the corresponding ELA-depressions have been calculated in comparison with the current courses of the orographic snow-line. The number of the glacier stages since the maximum glaciation approx. agrees with that e.g. in the Alps and the Rocky Mountains since the last glacial period. Accordingly, it is interpreted as an indication of the Wurmian age (last glacial period) of the lowest ice margin positions. The current climatic, average glacier snow-line in the research area runs about 5500 m asl. The snow-line depression (ELA) of the last glacial period (Wurm) calculated by four methods has run about 3870 m asl, so that an ELA-depression of c. 1630 m has been determined. This corresponds to a lowering of the annual temperature by c. 8, i.e., 10°C according to the specific humid conditions at that time.

Late Quaternary glacier advances in the upper catchment area of the Indus River (Ladakh and Western Tibet)

Geomorphological mapping in the Markha valley and the northern Nimaling Mountains (Northern Zanskar Range) has revealed eight prominent glacial stages. The two oldest glaciations are marked by glacial abrasion forms as ice-scour limits and glacial benches above the lower and middle Markha valley. These glaciations probably occurred prior to the last glacial cycle. Furthermore, terminal and lateral moraines, glacial tongue basins, basal moraines and tills provide evidence for three glacial stages in the Markha and Nimaling valleys, when the equilibrium-line altitude (ELA) depression was 670–350 m. The glaciations probably occurred during the LGM, the Lateglacial and the Lower Holocene as indicated by the topographic sequence, the ELA depressions and the tentative glacial stratigraphic divisions for the North Indian areas. Large moraine complexes in the vicinity of the present glaciers probably represent three glacial stages of Neoglacial and Historical glacial advances. The ELA depressions are 10–70 m. The present glaciation of the Nimaling Mountains, largely restricted to north flanks and the glacier basins below, covers an area of 45–55 km 2. The modern ELA is calculated at 5650–5750 m a.s.l. on north faces, rising to about 5900–6000 m a.s.l. on south faces. In the central and southern parts of the Ayila Ridge (Western Tibet) present ELAs range from 5700 to 5800 m a.s.l. on the north-facing slopes to 6000–6100 m a.s.l. on southern slopes. Eight former glacier stages are preserved on the southwest flank of these mountains by lateral and terminal moraine ramparts. The ELA depressions amount to 640–950 m.

The Maximum Ice Age (Würmian, Last Ice Age, LGM) Glaciation of the Himalaya – A Glaciogeomorphological Investigation of Glacier Trim-lines, Ice Thicknesses and Lowest Former Ice Margin Positions in the Mt. Everest–Makalu–Cho Oyu Massifs (Khumbu and Khumbakarna Himal) Including Informations on Late-glacial, Neoglacial, and Historical Glacier Stages, their Snow-line Depressions and Ages

In the Khumbu- and Khumbakarna Himalaya an ice stream network and valley glacier system has been reconstructed for the last glacial period (Wurmian, Last Ice Age, Isotope stage 4–2, 60–18 Ka BP, Stage 0) with glaciogeomorphological and sedimentological methods. It was a part of the glacier system of the Himalaya and has communicated across transfluence passes with the neighbouring ice stream networks toward the W and E. The ice stream network has also received inflow from the N, from a Tibetan ice stream network, by the Kyetrak–Nangpa–Bote Koshi Drangka in the W, by the W-Rongbuk glacier valley into the Ngozumpa Drangka, by the Central Rongbuk glacier valley into the Khumbu Drangka and by the antecedent Arun Nadi transverse-valley in the E of the investigation area. The ice thickness of the valley glacier sections, the surface of which was situated above the snow-line, amounted to 1000–1450 m. The most extended parent valley glaciers have measured approx. 70 km in length (Dudh Koshi glacier), 67 km (Barun–Arun glacier) and 80 km (Arun glacier). The tongue end of the Arun glacier has flowed down to ca. 500 m and that of the Dudh Koshi glacier to ca. 900 m a.s.l. At heights of the catchment areas of 8481 (or 8475) m (Makalu), i.e. 8848 (or 8872) m (Mt. Everest, Sagarmatha, Chogolungma) this is a vertical distance of the Ice Age glaciation of ca. 8000 m. The steep faces towering up to 2000 m above the neve areas of the 6000–7000 m-high surfaces of the ice stream network were located 2000–5000 m above the ELA. Accordingly, their temperatures were so low, that their rock surfaces were free of flank ice and ice balconies. From the maximum past glacier extension up to the current glacier margins, 13 (altogether 14) glacier stages have been differentiated and in part 14C-dated. They were four glacier stages of the late-glacial period, three of the neoglacial period and six of the historical period. By means of 130 medium-sized valley glaciers the corresponding ELA-depressions have been calculated in comparison with the current courses of the orographic snow-line. The number of the glacier stages since the maximum glaciation approx. agrees with that e.g. in the Alps and the Rocky Mountains since the last glacial period. Accordingly, it is interpreted as an indication of the Wurmian age (last glacial period) of the lowest ice margin positions. The current climatic, i.e. average glacier snow-line in the research area runs about 5500 m a.s.l. The snow-line depression (ELA) of the last glacial period (Wurm) calculated by four methods has run about 3870 m a.s.l., so that an ELA-depression of ca. 1630 m has been determined. This corresponds to a lowering of the annual temperature by ca. 8, i.e. 10 °C according to the specific humid conditions at that time.