Search

Only at Cape Surprise, central Transantarctic Mountains, is there exposed stratigraphic evidence for major offset along the range front, which marks a major boundary in Antarctica. Several faults parallel to the range front have been identified in the Devonian to Triassic Gondwana strata in the hinterland. Analysis of the stratigraphy based on field observations and the United States Geological Survey (USGS) aerial photographs, in conjunction with USGS topographic sheets and satellite-derived elevation measurements, suggests an array of faults with varying orientations and displacements. Fault offsets range up to an estimated 850 metres. No additional range-parallel faults have been identified and no clear pattern of faulting is evident in the hinterland of the frontal escarpment. Faulting may date from the time of slow uplift during the Cretaceous as well as the more rapid Cenozoic uplift of the range. Only a few faults in the hinterland can be allied with the fontal fault system. Cenozoic uplift and associated denudation was accompanied by glaciation of Antarctica, which is documented by Sirius Group strata. These deposits, which pre-date today's polar landscape, are older than mid Miocene, and in part may date from the earliest stages of warm-based glaciation in the early Oligocene. [ABSTRACT FROM AUTHOR]

We review the major phylogeographic patterns in Aotearoa New Zealand's terrestrial flora and fauna that have been associated with the Ōtira Glaciation of the Pleistocene, the end of which coincides with the global Last Glacial Maximum (LGM). We focus on (1) the complexity of biogeographic histories of New Zealand species, with LGM-driven phenomena overlaying the impacts of mountain-building and other drivers of phylogeographic structure; (2) the locations of glacial refugia and sets of taxa which may have shared refugia; and (3) the role of glaciation in driving diversification. We end with a brief focus on the next directions, including what can we learn about New Zealand's glacial history by expanding our phylogeographic toolbox to include genomic methods and hypothesis-driven inference methods. We provide follow-up questions which take advantage of the wealth of phylogeographic data for New Zealand. [ABSTRACT FROM AUTHOR]

Information on the nature of processes occurring in modern glaciers can be obtained through the study of diamictons and landforms that are the product of past glaciations. Macrofabric and grain size analysis of late Quaternary glacial diamictons and moraines present in several valleys of the Serra da Cabreira Mountains in northwest Portugal revealed the presence of two types of diamictons deposited in different stages and were used to re-construct the glacial paleo process history of this mountainous region. Supraglacial melt-out tills and paraglacially reworked tills by debris flows are dominant in this range. Supraglacial melt-out tills, representative of periods of glacial stability followed by recession, present girdle to transitional fabrics and coarser to medium, poorly sorted sediments. Paraglacially reworked tills by debris flows, representative of postglacial mass wasting activity, present girdle fabrics and coarser, poorly sorted sediments. These diamictons and landforms are of particular importance in the reconstruction of the glacial dynamics and history of the Serra da Cabreira Mountains due to a scarcity of chronological data based on absolute dating methods. These Atlantic mountains are also the lowest glaciated range in the Iberian Peninsula, which makes them a compelling area to investigate mountain glacial dynamics in low-elevation Atlantic ranges. [ABSTRACT FROM AUTHOR]

Sharks are virtually absent from coastal Antarctica since the Late Eocene glaciations, but this group exhibited a notable austral diversity during the Cretaceous and Paleogene. Several species have already been described from the Aptian-Eocene successions of the Larsen Basin exposed in the James Ross Island area (northern Antarctic Peninsula) and the predominantly deep-water Hexanchiformes have a record that, although still rare, has been continually increased. Four species of this group are currently known from that basin: Notidanodon pectinatus, Xampylodon dentatus, Rolfodon thompsoni, and Rolfodon tatere. Such records are especially concentrated in the Gamma Member of the Snow Hill Island Formation (or Herbert Sound Member of Santa Marta Formation), on James Ross Island. Here we described four teeth assigned to X. dentatus and one identified as R. tatere from upper Campanian sections of James Ross Island, highlighting the nomenclatural changes that led to the definition of Xampylodon and Rolfodon. Some specimens of X. dentatus presented here are considerably more complete or represent teeth of different positions than most previous records. The material assigned to R. tatere represents the oldest record of this species in the world, extending its time range by more than 10 million years. [ABSTRACT FROM AUTHOR]

Natural analogues are systems that have evolved over geological timescales with features similar to one or several components of a deep geological repository (DGR). Natural analogues complement short-duration laboratory studies since they are existing reflections of many long-term processes that might affect the performance of a repository. Mathematical models are often used for the post-closure safety assessment of a DGR. Confidence in the models' predictions is enhanced when the models successfully simulate the past evolution of a natural analogue. This paper summarizes the Canadian Nuclear Safety Commission's (CNSC's) recent research on natural analogues to inform on (1) glacial erosion, (2) engineered barrier system, and (3) uranium reactive transport in the context of DGRs for radioactive wastes. Glaciation and its erosion are prominent factors impacting the performance of future DGRs at high latitudes in the northern hemisphere. The authors have reviewed the field data from the Greenland Analogue Project, developed a conceptual and mathematical model for the simulation of the thermal conditions within the Greenland ice sheet, as well as the thermal-hydraulic conditions at its base and the ice sheet velocity, and eventually estimated the erosion rate at the site. The Cigar Lake Analogue demonstrates the long-term radionuclide containment capability of the illite clay zone enveloping the ore body, serving as an analogy to the engineered clay barriers. The CNSC and University of Ottawa analyzed 129I in the Cigar Lake core samples, and modeled and correlated the diffusion-dominated transport of radionuclides over the geological evolution of the Cigar Lake deposit. The results provide information on the mobility of fission products and significant radionuclides in conditions analogous to the source, engineered barriers, and near-field host rock of a DGR. The reactive transport and geochemistry of the Kiggavik-Andrew Lake uranium deposit mineralization and remobilization was another natural uranium deposit analogue studied by the CNSC. A reactive transport model was established according to the conceptualized geochemical processes and run under specified boundary and initial conditions to validate the geochemical processes. The geometry, timing, geochemistry, and fluid composition were used as model constraints. [ABSTRACT FROM AUTHOR]

While glaciation in the English Lake District and the Scottish Highlands was extensive after the retreat of the last British-Irish Ice Sheet, glaciers are thought to have been restricted to the highest uplands of southern Scotland. However, geomorphological features in the Ewes Valley indicate glacial activity in three amphitheater-shaped hollows after the retreat of the last British-Irish Ice Sheet. The geomorphological evidence of former glaciation is used to reconstruct the dimensions of three very small glaciers (totally ∼0.3 km2) with equilibrium line altitudes (ELA) between 329 and 401 m asl. An assessment of the glacier dimensions and potential snowblow contribution area indicates that redistribution of snow via wind was essential for the development of these glaciers. [ABSTRACT FROM AUTHOR]

Sedimentary manganese (Mn) deposits in the southeastern Yangtze Platform of China have been newly discovered with considerable potential for resource exploration. Such deposits formed due to dynamic changes in the global environment, including the break-up of the supercontinent Rodinia, Snowball Earth glaciation, and the Neoproterozoic Oxygenation Event. The Mn-bearing sequences are hosted in the basal Datangpo Formation and are interbedded with black carbonaceous shale in a series of graben sub-basins in the Nanhua Rift Basin. We investigated the origin of these Mn deposits by analysing the major and trace elements, total organic carbon, and stable carbon and oxygen isotopes. Positive Eu anomalies were observed, indicating that the Mn was derived from a hydrothermal system. Redox-related elements, including Ce, Mo, U, V, S, and P, indicated that the depositional environment of the Mn layers was oxidative and that Mn2+ was initially oxidized to Mn oxides. However, the host rock (i.e. black carbonaceous shale) was deposited under dysoxic – anoxic and even sulfidic water conditions. The alternating distribution of Mn ore and host rock suggested alternating redox conditions in the sub-basins. A negative correlation between the Mn content and δ13Ccarb values (−10‰–−7‰) and a deficiency of sulphide minerals indicate that the diagenetic degradation of organic matter (δ13Corg from − 34‰ to − 31.9‰) took place through Mn oxide reduction rather than microbial sulphate reduction and can contribute to a considerable source of bicarbonates. The approximately homogeneous δ13Ccarb depletion and their apparent discrepancy with δ13Corg indicate that the post-depositional genesis of the Mn carbonate ore occurred in a relatively open early diagenetic pore water system with a considerable contribution from seawater-derived carbon sources. [ABSTRACT FROM AUTHOR]

Abstract\nKEY POINTSA time discrepancy of at least 200–300 million years exists between the generally accepted onset of metazoan evolution as currently evidenced from fossils compared with that from studies at the molecular level. That temporal disparity coincides with the existence and subsequent breakup of the Rodinia Supercontinent when the earliest evolutionary crucibles were isolated intracratonic basins rather than the globally connected shallow seaways of subsequent eras. However, the discovery of fossil evidence to complement the extrapolations from molecular data has been, and continues to be, hampered, by both the geographical limitations of these isolated intracratonic basins and the fact that any such discovery would conflict with the global geological mindset that macrofossils of such age do not exist. Yet recently identified within the intracratonic Amadeus Basin of central Australia is a suite of macroscopic metazoan fossils that dates to ca 850–840 Ma, exemplifying an early attempt at animal evolution within the restrictions of the Rodinia Supercontinent. Such early metazoan evolution within such isolated crucibles, however, was extremely vulnerable to variations in climatic conditions, which threatened total extinction because the isolation of these basins limited metazoan distribution by denying them the possibility of migrating to safer havens. The Amadeus Basin evidence suggests that early metazoan evolution perhaps comprised cycles of about 10 million years when evolution flourished followed by climate change induced extinction and a subsequent evolutionary void of between 50 and 100 million years. Such cycles possibly characterised metazoan evolution until the Rodinia Supercontinent broke-up, after which connections between smaller oceans, shallow seas and narrow waterways provided metazoan life passageway to sanctuary during times of environmental stress. As the Amadeus Basin was just one of a number of isolated Rodinian-aged intracratonic basins, it is likely that similar fossils of the earliest metazoans are preserved elsewhere awaiting discovery.Metazoan evolution is widely believed to have followed the Gaskiers Glaciation at ca 580 Ma, yet studies at the molecular level suggest evolution began 200–300 million years earlier.Fossils discovered in the Amadeus Basin of central Australia suggest that a diverse metazoan biota had evolved by 850 Ma.Before the Rodinia Supercontinent fragmented during this temporal disparity, intracratonic basins acted as crucibles for early metazoan evolution.Being isolated, intracratonic basins were vulnerable to periodic environmental change causing metazoans, with no means of escape, to periodically become extinct.Amadeus Basin fossils suggest that pre-Ediacaran metazoan evolution possibly comprised cycles of ca 10 million years when evolution flourished before extinction and a following evolutionary void of between 50 and 100 million years. [ABSTRACT FROM AUTHOR]

The Radochowska Cave is known primarily from the find of a cave bear skull, intended to be placed intentionally by Palaeolithic hunters in a 'stone cage'. This find was supposed to be proof of the existence of the cult of bear hunters at this site. Critical analysis did not give a clear answer to its occurrence or a clear negation of this phenomenon. Research is not facilitated by the fact that a large part of the collection was lost after World War II. The found part, especially numerously represented by predatory mammals, made it possible to verify the old lists of fauna and extend them with a number of new species, often unknown from the Polish Sudetes, such as Cuon alpinus europaeus or Panthera pardus. The analysis showed the presence of two main faunistic associations. The older one, dated to MIS 3, is represented by a number of cold-loving forms. Remains of Holocene species and those from the very end of the last glaciation represent the second faunal assemblage. [ABSTRACT FROM AUTHOR]

This article provides a detailed analysis of the Egelsee site in Bad Tölz, Bavaria, Germany. The site is a terrestrialisation mire located in a kettle hole within the terminal moraine of the Würm piedmont glaciation. The core taken from the mire consists of lake sediment, fen peat, and bog peat, and the chronology is based on 13 accelerator mass spectrometry carbon-14 dates. The analysis of pollen samples covers the Late Weichselian period and the entire Holocene, identifying seventeen different local pollen assemblage zones. The document describes the changes in vegetation over time, including the dominance of Pinus and Betula, the increase of Corylus and mixed oak forest, and the eventual dominance of hazel, Picea, Fagus, and Abies. The document also discusses the potential influence of human activity on the vegetation changes and acknowledges the assistance of Dr. Susanne Lindauer, Dr. Ronny Friedrich, and Anna Schubert in the research. [Extracted from the article]

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 km²), 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. [ABSTRACT FROM AUTHOR]

Atmospheric aerosol particles can impact the optical depth of mixed-phase clouds through heterogeneous ice nucleation. Ice nucleating particles (INP) are therefore important contributors to global and local climate but remain under-parameterized in climate models, partially due to the complex interaction between composition and processing conditions. In this article, we study the ice nucleation (IN) activity of montmorillonite bentonite clay which is a common model dust INP, utilizing a 150-well microfluidic device. Refreezing tests are carried out for solutions across a range of salinity and pH to determine the impact of composition and processing on droplet freezing behavior, with and without an intermediate relative humidity (RH) cycling step. It is found that freezing order deviation dramatically increases after droplets undergo RH cycling, and the potential influence on IN activity of delamination of clay when subjected to changing RH conditions is discussed. Freezing order deviation decreases with increasing solution ionic strength, a trend linked to the delamination behavior of bentonite clays, and an overall decrease in IN activity at low pH is observed, possibly due in part to pH-dependent changes in clay aggregate size distribution. The authors conclude that pH changes and RH processing, such as those which naturally occur in the atmosphere, have a marked impact on the IN activity of clay-containing aerosol droplets. Copyright © 2024 American Association for Aerosol Research [ABSTRACT FROM AUTHOR]

We analysed the pollen and spores extracted from 73 samples of lacustrine sediments from Colesdalen in Svalbard (Lake Tenndammen) as well as 10 soil samples collected from the lake's shores. In total, 56 pollen taxa were recorded from the sediments spanning the last 800 years, whilst 35 pollen types were found in the soil samples. Pollen was categorised as (i) regional (from Svalbard); (ii) exotic to Svalbard today; or (iii) of mixed or unclear origin. Major changes in pollen assemblages after ca 1900 CE were associated with human impact. Around 1920 CE, the first signs of introduced plant taxa were identified, by the presence of Apiaceae and Fabaceae pollen. Additionally, large-sized pollen with a thick exine and annulus diameter of 10.6–13 μm, identified as Poaceae/Cerealia type, was constantly present after ca 1920 CE. Other exotic pollen, including Ulmus, Juglans, and tropical pollen of Albizia/Mimosa type, Eucalyptus type, Acalypha type, and Passiflora type, are found only during the 1930s to 1960s, which is the period associated with the most intensive mining activity and human migration to and from Colesdalen. Furthermore, the repeated occurrence of Myrica (gale) type and Erica type occurring both in the lake sediment and in the soil samples is best explained by the migration of geese from Scotland (UK). Our research demonstrates how precisely human history can be reflected in the lake sediments of the Arctic environment. [ABSTRACT FROM AUTHOR]

Recognizing stratigraphically important bounding surfaces relies on assessing the facies that juxtapose these surfaces as well as the trace fossil omission suite associated with the surface. The ability to differentiate between purely transgressive surfaces and those that conceal earlier stratigraphic surfaces that allude to a more complex history of development regarding the identification of allogenic surfaces of sequence stratigraphic significance that might have otherwise been overlooked. This study analyzes four examples of transgressive surfaces of erosion from Cretaceous-aged strata, with three of the examples representing a TSE/SB (amalgamated transgressive surface of erosion with a sequence boundary) that mask earlier base level falls. Consideration of variable omission suites along depositional strike and dip highlights the influence of substrate rheology on the nature of omission suites. In this study we demonstrate marked changes in the omission suite along bounding surfaces along proximal to distal trends that arise due to changes in underlying rheology. Finally, detailed core analysis is shown to be an imperative asset to subsurface investigation to address the limitations of using wireline well data alone in identifying stratigraphically important surfaces for more accurate regional mapping and characterization of transgressive surfaces. This study highlights that many stratigraphically important surfaces such as those that correspond to a TSE/SB may go unnoticed if utilizing wireline data alone. Overall, this study provides a comprehensive approach to further understanding and identifying transgressive surfaces in the rock record, especially those that demarcate a more complex history other than simple transgressive ravinement. [ABSTRACT FROM AUTHOR]

Tamarix hispida Willd. 1816, a crucial native plant species in the arid desert region of northwestern China, plays a significant role in maintaining ecological stability. It is instrumental in addressing soil salinity–alkalinity and heavy metal pollution. This research aims to analyze the phylogenetic divergence pattern and evolutionary history of T. hispida by comparing chloroplast genome structures across different populations. Despite the minimal differences in chloroplast genome structure due to conserved genes and junction regions, sequencing was conducted using the Illumina NovaSeq platform to verify the historical evolutionary processes between different populations, followed by assembly and annotation. The results revealed that the T. hispida chloroplast genome is approximately 156,164–156,186 bp in length, with a quadripartite structure and 131 annotated genes. Phylogenetic analysis indicated two lineages within T. hispida, with a divergence time of 3.15 Ma. These findings emphasize the low genetic diversity in T. hispida and offer valuable insights into its evolutionary past. To effectively protect and manage this species, increased scientific research and monitoring of its genetic diversity are necessary. This study underscores the importance of comprehending the genetic mechanisms behind species divergence to develop informed conservation strategies. [ABSTRACT FROM AUTHOR]

Two water frog species: the pool frog Pelophylax lessonae (L) and the marsh frog P. ridibundus (R) occur sympatrically in Central Europe and form mixed populations (genetic systems) with their hybrid, the edible frog P. esculentus (E). The aim of the study was to assess the species composition of water frogs in urban and rural populations and compare our current findings with the results of previous studies. We surveyed the same sites that were investigated by Berger et al. in 1962–1970 (Poznań, urban landscape) and 1977–1997 (Dezydery Chłapowski Landscape Park, rural landscape). Because some ponds surveyed in the past were destroyed or dried-up, we also explored others located in the adjacent areas. We captured frogs during breeding seasons 2020 and 2021 and identified them by the nuclear marker gene SAI-1. We found three types of populations in the urban area: R-E, E-E and R-E-L and four in the rural area: R-E, L-E, E-E and R-E-L. Compared to the historical data, we found a drastic decrease in the frequency of P. lessonae in urban and rural landscapes: from 89.1% and 68% to 2.7% and 1.8%, respectively. At the same time, the frequency of P. ridibundus increased from 2.2% and 0.1% to 40% and 29.6%, respectively. A similar pattern was found for P. esculentus whose frequency increased from 8.7% and 31.9% to 57.3% and 68.6%, respectively. Additionally, we confirmed the presence of a cryptogenic Balkan water frog, P. kurtmuelleri, which was recently discovered in south-western Poland. The frequency of SAI-1 allele specific for this taxon reached 7.3%. The patterns found in both types of landscapes are in line with the current situation of both parental species in Europe. Such dynamic changes show the need for long-term monitoring of the population compositions of water frogs, what is crucial for their conservation management. [ABSTRACT FROM AUTHOR]

Chitinozoan investigations on the late Middle to early Late Ordovician in South China are limited. Documented chitinozoan occurrences are mainly from the Miaopo Formation on the Upper Yangtze Platform. The present study reports new data from the Miaopo Formation at the Zhenjin section in the Yichang area. In total, 13 genera and 33 species are recognised, and three new species are described: Spinachitina? coronifera sp. nov., Lagenochitina yichangella sp. nov. and Pellichitina confragosa sp. nov. The Baltoscandian index species, Laufeldochitina striata, is documented in the lowermost part of the formation. This is the first report of this species in South China. The L. striata Biozone is suggested for the basal part of the formation due to the presence of the eponymous species. The index species of the Laufeldochitina stentor Biozone, the Armoricochitina granulifera and Cyathochitina megacalix subzones adopted in the Jieling section, are also observed in the Zhenjin section. However, according to the new data obtained at Zhenjin, the first appearance datum of C. megacalix and A. granulifera coincides with that of L. striata. Therefore, the C. megacalix Subzone is kept but moved to the L. striata Biozone. Armoricochitina granulifera has stable occurrences in almost the entire Miaopo Formation, corresponding to the Nemagraptus gracilis graptolite biozone. It is slightly older than Baltic records but could be useful for recognising this time interval in South China. [ABSTRACT FROM AUTHOR]

Copyright of Azania: Archaeological Research in Africa is the property of Routledge and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Langbein and Schumm (1958) connected precipitation to erosion in a right-skewed curve used in earth science textbooks for over six decades, where denudation increases with precipitation on the arid/semiarid limb and decreases in humid regions. Development of the catchment-averaged 10Be denudation method a quarter-century ago led geomorphologists to evaluate this hypothesis using data not influenced by the Anthropocene, with mixed findings. The Sonoran Desert in Arizona, USA, is optimal for investigating the longstanding hypothesis of increased erosion from arid to semiarid climates due to: (i) the modern orographic effect aligning elevated precipitation with altitude, mirroring Neotoma packrat midden paleoecology research for the Holocene and late Pleistocene; (ii) the region has been tectonically quiet for the residence times of analyzed 10Be ranging from ca. 8,000-110,000 years. Our significant finding echoes Langbein and Schumm's work, revealing heightened erosion along an elevation-precipitation gradient from arid to semiarid conditions. Notably, the significance of precipitation-elevation contrasts with the absence of significant correlation between 10Be denudation and attributes like slope, drainage area, relief, or landform type (e.g., alluvial fan, pediment, mountain watershed). Modern faunalturbation, increasing along this gradient, exposes more ground to rainsplash and overland flow at higher elevations, adding complexity to these results. Further insights unveil that (i) catchments in areas with substantial Quaternary base level reduction imitate tectonic effects, tripling 10Be denudation rates; (ii) basaltic boulders and cobbles yield an armoring influence; (iii) historical erosion acceleration due to urbanization and wildfires insignificantly affects 10Be denudation rates in the Sonoran Desert; and (iv) minute desert catchments yield anomalous erosion rates. [ABSTRACT FROM AUTHOR]

The Late Jurassic petroleum system has created a distinct oil family in the Jurassic and Cretaceous reservoirs in the eastern part of the Persian Gulf. Although the oils in this oil family indicate genetic affinity with the Middle Surmeh source rock, some oil samples show geochemical deviation compared to others. The purpose of this study is to gain a better understanding of these geochemical differences among 23 oil samples from the Jurassic oil family in the eastern Persian Gulf. To achieve this, physical and chemical properties of oil samples, biomarker ratios, stable carbon isotope data, and multivariate statistical methods were used. The chemometric analysis of twenty source-related parameters differentiates three genetic subfamilies (Jurassic principal subfamily, Resalat-Dariyan, and Balal-Surmeh) from Jurassic petroleum system oils. The Balal-Surmeh and Resalat-Dariyan samples are distinguished from principal subfamily based on depositional environment and maturity parameters. The Balal-Surmeh samples show a more marine characteristics and a high maturity level due to the contribution of Permo-Triassic condensates or Silurian Sarchahan shales as a secondary source. It seems that the limited oil generation of the low mature organic-rich interlayers of Dariyan Formation caused a low maturity level in the Resalat-Dariyan samples. [ABSTRACT FROM AUTHOR]

The Cordillera Darwin Icefield (CDI) has experienced widespread retreat since the Little Ice Age (LIA, ~1870 AD). Prior to this, information on outlet glacier dynamics is limited as there are few terrestrial observations and little mapped deglacial evidence, limiting our understanding of CDI dynamics on Holocene centennial to millennial timescales. Here we present a glacial geomorphological map of terrestrial landforms and features for the CDI and surrounding areas of the Tierra del Fuego archipelago. We digitized more than 8,000 glacial landforms and features covering an area of ~13,300 km² from a combination of digital elevation models (DEMs) and high-resolution satellite and aerial imagery (<3 m), supported by multitemporal field mapping. This work provides a detailed geomorphological assessment for the area, summarized in a single map, that identifies three main glacial landsystem types of the Patagonian--Fuegian landscape: (i) upland glacier, (ii) lowland land-terminating, and (iii) glaciomarine fjord. The resulting map forms the basis for future chronological campaigns. [ABSTRACT FROM AUTHOR]

This paper presents a map of terrestrial glacial geomorphology of eleven surge-type and nonsurge- type glacier forefields in southwest and west Spitsbergen, Svalbard. Glacier forefields were mapped using a combination of field surveys and the use of an uncrewed airborne vehicle in September 2022 and satellite imagery captured in 2020, with mapping performed in ArcGIS Pro at a 1:5000 scale. Maps were constructed for glaciers in Van Kuelenfjorden and Van Mijenfjorden (southwest Spitsbergen), and in Isfjorden, Billefjorden a fjord branch of Isfjorden and St. Jonsfjorden (west Spitsbergen), to obtain a breadth of glacier types and features representative of glacial landsystems on Svalbard. The detailed landform inventory was divided into: (i) ice marginal, (ii) subglacial, (iii) glaciofluvial and glaciolacustrine, (iv) supraglacial and (v) other non-glacial and contemporary features. These detailed maps provide a geomorphological insight into the past and present characteristics of glaciers on Svalbard. [ABSTRACT FROM AUTHOR]

In this study, we present a GIS dataset and map of icings formed in the transboundary Selenga River basin (largest tributary of the Lake Baikal). The GIS dataset of icings is compiled using Landsat and Sentinel-2 satellite images, as well as materials from the field expedition studies. It contains 29,054 individual icings with a total area of 1154.2 km² (0.25% of the entire basin area), including at least 56 giant icings with an area ≥ 1 km². Icings are widespread throughout the basin, but the highest icing coverage is found on the northern slopes of Hangayn ridge in the southeastern part of the basin, where most of the giant icings are located. The highest density of icings (more than 200 per km²) is found in the eastern part of the basin. Since icings can indicate climate-driven changes in streamflow and permafrost, the presented dataset will form the basis for future studies of these transformations. [ABSTRACT FROM AUTHOR]

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

The paper provides a comprehensive overview of the transformation of the glacial isthmus between Sørkapp Land (southern peninsula) and the remainder of Spitsbergen from 1900 to 2023. The region distinguishes itself with notable environmental and landscape transformations since the early twentieth century, the post-Little Ice Age. These ongoing transformations are poised to swiftly convert the Sørkapp Land peninsula into an island, driven by the decline of the glacial isthmus connecting Sørkapp Land to the rest of Spitsbergen. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

The MaGIC project (Marine Geohazard along the Italian Coasts) had the aim of mapping the geohazard in the Italian seas and resulted in numerous maps. In this paper, we present the maps: 'Maps of Geohazard features of the eastern Sardinian Margin'. The Eastern Sardinia margin has mainly a narrow shelf, which reaches a width of 20 km only to the north. At the base-of-slope, a series of intra-slope basins sits in the structural depressions formed during the opening of the Tyrrhenian back-arc system. Submerged, coastal depositional bodies are present in the Olbia area where the continental shelf is large. They most likely represent the remnants of coastal environments formed during the last rise in sea level. They can represent important geo-resources for application in the issue of coastal erosion management. They are also the site of ecosystems hosting a specific biodiversity, which need to be preserved. In the central and southern part of the mapped area, the shelf is very narrow with an average width of about 4 km. Here, many canyon heads are very close to the coastline. They develop through retrogadational processes. Particularly in those canyons, where the canyon heads reach the coast, sediment instability represents an important source of geohazards to the coastal regions. [ABSTRACT FROM AUTHOR]

The study utilizes an integrated approach that involves GRACE and Global Precipitation Climatology Project (GPCP) data to analyze temporal water mass variations in Saudi Arabia (KSA). Recently, KSA has witnessed a historic wet period between 2018 and 2020 (i.e., 120–150 mm/year) following a prolonged dry period between 2002 and 2017 (i.e., 80–100 mm/year). Inspection of GRACE data showed a decline in groundwater recharge of −4 to −6 mm during the dry period. The depletion was reduced by 1 to 6.8 mm in the Northeastern side of KSA (e.g. Hail, Al-Jouf, Al-Hudud Ash-Shamaliyah areas) during the wet period. This impressive recovery has led to a groundwater recharge increase of 360 km³ in Hail, 174 km³ in Al-Jouf and 97 km³ in Al-Hudud Ash-Shamaliyah. The findings emphasize the notion that climate change will bring more frequent extreme climatic events to the Kingdom of Saudi Arabia and call for continuous monitoring of aquifers every year. [ABSTRACT FROM AUTHOR]

The complete mitochondrial genome of Chrysemys dorsalis in Korea was sequenced and characterized. The mitochondrial genome is 17,258 bp in length and the GC content is 39%. It is constituted of 37 genes, 13 protein-coding genes, 22 transfer RNA genes, 2 ribosomal RNA genes, and a noncoding region. Phylogenetic analysis reveals that C. dorsalis forms a monophyletic group with C. picta turtles but is distinctly separated from them, aligning with previous findings. In Korea, C. dorsalis forms a discrete clade, separate from both native and invasive turtle species. No evidence of genetic disturbance or intermingling is observed. This is the first case of a complete mitochondrial genome from C. dorsalis and provides crucial data for understanding C. dorsalis and managing invasive species effectively, emphasizing the need for continued mitochondrial genome data accumulation. [ABSTRACT FROM AUTHOR]

This study compares the performance of ensemble machine learning methods stacking, blending, and soft voting for Landslide susceptibility mapping (LSM) in a highly affected Northern Italy region, Lombardy. We first created a spatial database based on open data ensuring the accessibility to relevant information for landslide-influencing factors, historical landslide records, and areas with a very low probability of landslide occurrence called 'No Landslide Zone', an innovative concept introduced in this study. Then, open-source software was employed for developing five Machine Learning classifiers (Bagging, Random Forests, AdaBoost, Gradient Tree Boosting, and Neural Networks) which were tested at a basin scale by implementing different combinations of training and testing schemes using three use cases. The three classifiers with the highest generalization performance (Random Forests, AdaBoost, and Neural Networks) were selected and combined by ensemble methods. The soft voting showed the highest performance among them. The best model to generate the LSM for the Lombardy region was a Neural Network model trained using data from three basins, achieving an accuracy of 0.93 in Lombardy. The LSM indicates that 37% of Lombardy is in the highest landslide susceptibility categories. Our findings highlight the importance of openness in advancing LSM not only by enhancing the reproducibility and transparency of our methodology but also by promoting knowledgesharing within the scientific community. [ABSTRACT FROM AUTHOR]