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Salt structures and their surroundings can play an important role in the energy transition related to a number of storage and energy applications. Thus, it is important to assess the current and future stability of salt bodies in their specific geological settings. We investigate the influence of ice sheet loading and unloading on subsurface salt structures using physical models based on the geological setting of northern Germany, which was repeatedly glaciated by the Scandinavian Ice Sheet during the Pleistocene. Apparent spatial correlations between subsurface salt structures in northern Germany and Weichselian ice marginal positions have been observed before, and the topic is a matter of ongoing debate. Recently described geomorphological features – termed surface cracks – have been interpreted as a direct result of ice-sheet-induced salt movement resulting in surface expansion. The spatial clustering and orientation of these surface cracks has not been well understood so far, owing to only a limited number of available studies dealing with the related salt tectonic processes. Thus, we use four increasingly complex physical models to test the basic loading and unloading principle, to analyze flow patterns within the salt source layer and within salt structures, and to examine the influence of the shape and orientation of the salt structures with respect to a lobate ice margin in a three-dimensional laboratory environment. Three salt structures of the northern German basin were selected as examples that were replicated in the laboratory. Salt structures were initially grown by differential loading and buried before loading. The ice load was simulated by a weight that was temporarily placed on a portion of the surface of the models. The replicated salt structures were either completely covered by the load, partly covered by the load, or situated outside the load extent. In all scenarios, a dynamic response of the system to the load could be observed; while the load was applied, the structures outside the load margin started to rise, with a decreasing tendency with distance from the load margin, and, at the same time, the structures under the load subsided. After the load was removed, a flow reversal set in, and previously loaded structures started to rise, whereas the structures outside the former load margin began to subside. The vertical displacements during the unloading stage were not as strong as during the load stage, and thus the system did not return to its pre-glaciation status. Modeled salt domes that were located at distance from the load margin showed a comparably weak reaction. A more extreme response was shown by modeled salt pillows whose margins varied from sub-parallel to sub-perpendicular to the load margin and were partly covered by the load. Under these conditions, the structures showed a strong reaction in terms of strain and vertical displacement. The observed strain patterns at the surface were influenced by the shape of the load margin and the shape of the salt structure at depth, resulting in complex deformation patterns. These physical modeling results provide more evidence for a possible interplay between ice sheets and subsurface salt structures, highlighting the significance of three-dimensional effects in dynamic geological settings. Our results lead to a better understanding of spatial patterns of the surface cracks that were mapped at the surface above salt structures and offer further room for interpretation of the influence of salt movements on the present-day landscape. [ABSTRACT FROM AUTHOR]

Investigating long-distance travelling routes is crucial for understanding both historical decision-making processes as well as possible regional points of interest that may have been lost in the course of time. Located in the northern Ethiopian highlands, the city of Aksum was the starting and return point for both, Ethiopian, Arabian, and European travellers on the north-south passage to Cairo, Jerusalem or Europe, at least from the fifteenth century onwards. We extracted locations from travel itineraries from the fifteenth and sixteenth centuries and analysed historical maps from the fifteenth to the twentieth centuries. This data was used to calculate several least-cost paths (LCPs). Results suggest that route planning in historical times was in some cases very cost effective, while in others, visiting specific locations may have played a major role in path selection. Additionally, LCPs based on historical waypoints reveal several remarkable historical locations along their way. [ABSTRACT FROM AUTHOR]

The Pomeranian Phase of the Weichselian glaciation in northern middle Europe has been the object of investigation in various studies aiming to derive numerical ages for this specific phase. Apart from traditional 14 C-chronologies, surface exposure dating with in-situ produced terrestrial cosmogenic nuclides and optically stimulated luminescence dating have been applied by different authors. The ages derived are so far not consistent. Generally, cosmogenic exposure dating results in younger ages (∼15 ka) and luminescence dating results in older ages (∼20 ka) for the formation of the Pomeranian Phase. The apparent age gap has been subject to discussions from both, methodological and geomorphological viewpoints. We recalculated compiled exposure ages with a recent calibration data set, which reflects very recent progress in cosmogenic nuclide dating, and received results that differ significantly from the originally published ages. The newly calculated ages deviate 9–15% from the original ages from the source studies towards the older age range, thus reducing the offset between the different dating methods and supporting the theory that the onset of the Pomeranian Phase was earlier in the marine isotope stage 2. In one example from northeast Germany, good agreement between both methods results from the recalculations, corroborated also by the local geomorphology. Nevertheless, postdepositional movement of glacial boulders as well as erosion and shielding effects are hard to quantify and most probably cause an underestimation of exposure ages. The study aims to contribute to a critical evaluation of existent chronologies for the southern margin of the Scandinavian Ice Sheet. [ABSTRACT FROM AUTHOR]

The Weichselian Frankfurt ice marginal position in northeast Germany has been critically discussed in the past owing to weak morphological evidence and a lack of clear sedimentological records. This study aims to contribute to this discussion with new geochronological and geomorphological results. Apart from very few cosmogenic exposure ages, the time frame is to date still based on long distance correlation with radiocarbon chronologies. We selected a study site in a key position regarding the classic location of the Frankfurt ice marginal position and the recently described arcuate ridge structures on the Barnim plateau. For the first time we present Optically Stimulated Luminescence (OSL) ages of quartz from glaciofluvial deposits for this Weichselian phase. Our results indicate an advance of the Scandinavian Ice Sheet (SIS) at around 34.1 ± 4.6 ka. This is in agreement with OSL ages from sandur deposits at the Brandenburg ice marginal position located farther south and could also be correlated with the Klintholm advance in Denmark. The subsequent meltdown phase lasted until around 26.3 ± 3.7 ka. During the meltdown phase a minor oscillation of the SIS caused the formation of the recently described arcuate ridges on the Barnim till plain. Recalculated surface exposure ages of glacigenic boulders with an updated global production rate indicate a landscape stabilization phase at around 22.7 ± 1.6 ka, which is in agreement with our ages. A phase of strong aeolian activity has been dated with OSL to 1 ± 0.1 ka; this may have been triggered by human activities that are documented in this region for the medieval period. [ABSTRACT FROM AUTHOR]

Despite more than a 100-year-long research history, timing and position of the last glacial ice margins in the northeast German lowland are still up for debate. The Barnim region, a till plain in the northeast German young morainic landscape, is traversed by the contradictorily discussed Frankfurt ice marginal position. It is located in a key position to reassess the current state of research with help of a geographic information system (GIS) and field methods. A qualitative geomorphological analysis of a high resolution LiDAR digital elevation model (DEM) in the Barnim area uncovers a variety of landforms that were previously not described. The most prominent discovery is a set of about 10 lobe-shaped ridges in the middle Barnim area. Fieldwork and geophysical measurements were carried out to investigate the structure of the ridges. The ridges are 1000–1500 m in length and their widths vary from 10 to 15 km. They are raised some 6–10 m from their surroundings. The Frankfurt ice marginal position can only partially be traced in the DEM. Sedimentological and geophysical investigations indicate that the ridges are composed of glacial till that was deposited on glaciofluvial sediments. Their formation most probably took place during the ice retreat of the Brandenburg phase (W 1B ) and hence represents the W 1F phase in the region. [ABSTRACT FROM AUTHOR]

The “tablelands” in Taiwan are sedimentary terraces occurring in the foreland basin west of the Neogene mountain ranges. The Miaoli Tableland consists of elevated Late Quaternary sedimentary successions, representing a change from tidal to coastal and fluvial to eolian depositional environments. The present-day morphology is a result of combined processes, including differential tectonic uplift, ongoing fluvial aggradation, and incision. Selected deposits in 10 outcrops were sampled and studied by optical dating. The deposition of fluvial sediments started after the last interglacial (<100 ka) in the southeast of the tablelands. Uplift and sea-level lowering caused a base-level fall, resulting in a stepwise redeposition of the fluvial sediments. Additionally, enhanced remobilization of fluvial sediments occurred during the cold/dry climate during Marine Oxygen Isotope Stages (MIS) 4 and 2. The depositional ages of the coastal sediments enabled the estimation of long-term uplift rates of ca. 0.5 to 3.5 mm/yr. The eolian cover sediments yielded MIS 3 (east) to Holocene ages (west). Our results provide new insight into the interplay of climate, sea-level changes, remobilization of sediments, and tectonism leading to tableland formation during the Late Quaternary. [ABSTRACT FROM AUTHOR]

In recent years, modeling gully erosion susceptibility has become an increasingly popular approach for assessing the impact of different land degradation factors. However, different forms of human influence have so far not been identified in order to form an independent model. We investigate the spatial relation between gully erosion and distance to settlements and footpaths, as typical areas of human interaction, with the natural environment in rural African areas. Gullies are common features in the Ethiopian Highlands, where they often hinder agricultural productivity. Within a catchment in the north Ethiopian Highlands, 16 environmental and human-related variables are mapped and categorized. The resulting susceptibility to gully erosion is predicted by applying the Random Forest (RF) machine learning algorithm. Human-related and environmental factors are used to generate independent susceptibility models and form an additional inclusive model. The resulting models are compared and evaluated by applying a change detection technique. All models predict the locations of most gullies, while 28% of gully locations are exclusively predicted using human-related factors. [ABSTRACT FROM AUTHOR]

The monumental Late Bonze Age royal tomb of Seddin is located in the old morainic landscape of the Prignitz region, northeastern Germany. Together with other richly equipped burials and a row of stone pits in its direct vicinity, it provides evidence for the presence of an elite from the nineth to sixth centuries BCE in this region. Our map emphasizes the well-chosen location of the royal tomb in relation to the spatial arrangement of other archaeological monuments that together form an ensemble of a ritual landscape. We trace legacies of land use from the Bronze Age to the present against the backdrop of Late Quaternary landscape evolution. These include the Bronze Age landscape (re-)organization for ritual and economic purposes, its medieval use for arable farming, its economic use and settlement history in historic times, and modern times melioration of agricultural areas that together form the palimpsest of the present-day landscape. [ABSTRACT FROM AUTHOR]

Significant progress was made in dating of Weichselian sediments in the south-western sector of the Scandinavian Ice Sheet (SIS) in Sweden, Denmark and Germany. Most ages are based on luminescence dating of glaciofluvial and glaciolacustrine sediments, and cosmogenic nuclide exposure dating of glacial boulders. The increasing number of numerical data gives new insights into the timing of various glacigenic, glaciofluvial and glacilimnic processes (Hughes et al., 2016). In Germany, the traditional names of ice advances like Brandenburg, Frankfurt and Pomeranian advance pretend a synchronous formation of ice marginal positions over some distance, not taking into consideration the varying ice dynamics at the distal part of the SIS. In this study, we review existing data and present a revised model of Weichselian ice dynamics in the SW sector of the Baltic Sea.During the early MIS3, according to the present knowledge, the Ellund-Warnow advance marks the first expansion of glaciers during the Weichselian into the SW Baltic Sea area. But it is only lithostratigraphically documented in western Mecklenburg and in parts of Schleswig-Holstein. During late MIS 3, the ice attained the maximum extent within the Oder lobe (Brandenburg advance) and reached into Denmark (Klintholm advance) (Hardt et al., 2016). Nevertheless, there is no evidence that Bornholm, the Rønne Bank as well as Rügen were overridden by ice at that time; instead glaciofluvial and glaciolacustrine sediments were deposited in ice dammed lakes. The area shaped by the maximum ice advance of the Oder lobe, dated to 32-28 ka, is mainly characterized by meltwater sediments and erosional channels, which are in accordance with the assumption of a fast flowing ice of an outlet glacier. Distinct terminal moraines are missing. Thus, various sedimentary environments existed in close neighborhood in the southwestern Baltic Sea basin and the surrounding areas, shedding new light on ice dynamics. The ice advance in correspondence with the global LGM at about 22-20ka, named Pomeranian advance in NE Germany, (Lüthgens & Böse 2011, Lüthgens et al. 2011), was likely characterized by slower moving ice, which can be deduced from the boulder-rich and distinct end moraines in northern Brandenburg, Mecklenburg-Vorpommern and in Schleswig-Holstein. Isochronic ice cover is also documented in the Baltic Sea basin and Denmark. The configuration and dynamics of the SIS in its southwestern part was therefore very different during the MIS 3 and MIS 2 ice advances, influenced by climatic parameters, and the topography of the Baltic Sea basin and adjacent areas. Hardt, J., et al., 2016: Geochronological (OSL) and geomorphological investigations at the presumed Frankfurt ice marginal position in northeast Germany. Quaternary Science Reviews 154, 85-99.Hughes, A., et al., 2016: The last Eurasian ice sheets – a chronological database and time-slice reconstruction, DATED-1. Boreas 45, 1-45.Lüthgens, C., Böse, M., 2011: Chronology of Weichselian main ice marginal positions in north-eastern Germany. E&G Quaternary Science Journal 60, 236-247.Lüthgens, C., et al., 2011: Age of the Pomeranian ice‐marginal position in northeastern Germany determined by Optically Stimulated Luminescence (OSL) dating of glaciofluvial sediments. Boreas 40, 598-615. [ABSTRACT FROM AUTHOR]

The cost of human movement, whether expressed in time, effort, or distance, is a function of natural and human related variables. At the same time, human movement itself, whether on land, air or sea, causes environmental cost. We are looking into the long-term environmental relationship of this interplay. Gullies—linear landforms, which dissect the landscape—are considered to be a cost for human movement, as they can form unpassable barriers destroying present path networks. On the other hand, human movement creates pathways, which flatten the surface and decrease the water permeability potential. This process results in runoff generation and possibly gully erosion. Accordingly, the spatial relationship between pathways and gullies is investigated. In the Tigray region of the Northern Ethiopian Highlands, gullies and pathways were mapped using remote sensing data. Frequency Ratio was used for assessing pathways as a variable affecting the location of gullies while Least Cost Paths were tested to evaluate the possible constraining impact gullies have on mobility. Based on these results, it is concluded that a positive feedback exists between the cost of human movement and gully erosion. We further discuss possible effects gullies may have had on trade, territory, and political affairs in Tigray. Consequently, we suggest that movement cost and gullying may not only hold strictly environmental or movement-related implications, but also socio-cultural ones. [ABSTRACT FROM AUTHOR]

Abstract: At the Hohuan Shan, a mountain massif well above 3400 m in altitude in northern Taiwan, a glacial deformation till has been observed in the uppermost part of the catchment of the Hohuan River. The sediment sequence above the slate bedrock is evidence of a late Pleistocene to early Holocene glaciation as dated in neighbouring mountain massifs, and is discussed in context with the results from a nearby outcrop with dated Holocene slope sediments. [Copyright &y& Elsevier]

• Reduction of macro pores are observed down to 3 cm below footpaths surfaces. • Footpaths promote changes of pedogenic iron oxides accomulations. • Some of the observed microstructures and Fe oxides are found in buried footpaths' surfaces. • Incised footpaths are more likely to be oriented paralel to the stream network. • Incised footpaths can reduce gully erosion susceptibility downslope. Footpaths are of the oldest and most widely distributed forms of human imprint on the landscape. These elongated features are the result of continuous usage of a certain route for walking, at time scales ranging from days to centuries or millennia. In this qualitative investigation, we take a holistic approach combining micromorphology (including voids analysis), chemical soil parameters (such as selective iron oxide dissolution), and remote sensing (spatial distribution and orientation of footpaths in the landscape) to evaluate the long-term residues and environmental effects resulting from the formation of footpaths. Our diverse case studies incorporate footpaths used for recreational and transport purposes in temperate and sub-humid climates from both recent and historical perspectives. A reduction of the large pores was observed down to 3 cm below current and historical surfaces compared to control areas without footpaths. The lower porosity subsequently hinders of the supply of oxygen and/or water into the sub-surface and encourages water stagnation on the compacted footpath surface. These processes result in higher amounts of pedogenic Fe oxides and, at times, macro-organic residues under footpaths and hindering of soil formation. As an additional result of compaction, surface runoff is promoted. The latter may either trigger the initiation of gullies directly downslope from footpaths or lead to incision of the footpaths themselves. Incised footpaths are more likely to occur when the footpath is oriented parallel to the stream network. Once an incised footpath is formed, it may reduce gully erosion susceptibility downslope as the incised footpath acts as a channel that decreases a footpath's 'overbank' flow. With a better understanding of footpaths as landscape units we can (1) pose archaeological questions related to human environmental interaction, (2) assess carbon storage potential under footpaths and (3) use incised footpaths as possible measures against gully erosion. [ABSTRACT FROM AUTHOR]