Quaternary Science Advances最新文献

{"title":"Morphological differences across the Shumagin-Semidi fault segments control slip behaviors and tsunami genesis in the Aleutian-Alaska subduction zone","authors":"Qiang Qiu ,&nbsp;Linlin Li ,&nbsp;Xiaodong Yang ,&nbsp;Jian Lin ,&nbsp;Constance Ting Chua","doi":"10.1016/j.qsa.2024.100215","DOIUrl":"https://doi.org/10.1016/j.qsa.2024.100215","url":null,"abstract":"<div><p>Rupture behaviors of a subduction megathrust define the slip type, the extent and the associated tsunami hazard. They are, however, difficult to be defined precisely due to limited fault-zone observations. Here, we integrate GNSS, tsunami-waveforms, seismic-profiles, and earthquake-cycle modeling to delineate the slip-extent of the 2020 M_w 7.8 Simeonof and the 2021 M_w 8.2 Chignik earthquakes in the Semidi segment; and to understand the possible structural and mechanical control on the distinct rupture behaviors of this segment and its neighboring Shumagin segment at the Aleutian-Alaska subduction zone. We show that both the Simeonof and Chignik earthquakes slipped a compact area at depth between ∼20 and 40 km that is well constrained by the combination of GNSS and tsunami-waveform data. We explain the distinct slip behaviors associated with the Semidi and Shumagin segments by highlighting the morphological changes in the fault along the strike direction. Beneath the Shumagin Island, we identify a structural-mechanical boundary that separates the megathrust into Semidi (east) and Shumagin (west) two segments. Semidi is gentle and curved; while Shumagin is steep and planar. The Semidi segment produces spatially-heterogenous stress field, and generates partial, full, complex ruptures as indicated in modeled cycles and in historical seismic observations. Meanwhile the Shumagin segment, coincides with the ocean-continent transition boundary – the Beringian margin, tend to generate slow-slip-events, tremors, otherwise, generates small or moderate seismicity as indicated in the modeled cycles and in seismic records since 1750. Our findings indicate that Semidi is likely to rupture in a chaotic fashion with major or large earthquakes, resulting a greater tsunami hazard like the 1938 M_w 8.2 event. The tsunami potential in the Unimak segment may also remain high.</p></div>","PeriodicalId":34142,"journal":{"name":"Quaternary Science Advances","volume":"15 ","pages":"Article 100215"},"PeriodicalIF":2.9,"publicationDate":"2024-07-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2666033424000534/pdfft?md5=91417bdff25e23d24a6adbd97b8a0f1d&pid=1-s2.0-S2666033424000534-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141596857","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Variation of ecosystem resilience across the anthropogenic biomes of India: A comprehensive analysis","authors":"Subhojit Shaw ,&nbsp;Aparajita Chattopadhyay ,&nbsp;Karikkathil C. Arun Kumar","doi":"10.1016/j.qsa.2024.100214","DOIUrl":"10.1016/j.qsa.2024.100214","url":null,"abstract":"<div><p>Quantifying ecosystem resilience under drought is crucial for sustainable development strategies. This study aims to investigate the spatial and temporal variability of Net Primary Productivity (NPP) across anthropogenic biomes in India (2000 to 2020) and to understand the post-drought long-term ecosystem resilience. A time series study of monthly precipitation, standardized precipitation index (SPI), and NPP were applied to understand ecosystem resilience across twenty anthropogenic biomes. Mann-Kendall test was used to quantify the magnitude and direction of the trend. In addition, bivariate raster maps of mean precipitation and soil moisture were presented in relation to ecosystem resilience in India. The forested areas in the Himalayan region and the Western Ghats of India were identified with resilient ecosystem that can withstand climate change. However, the croplands and rangelands were non-resilient to drought, making them vulnerable to climate change. Northern and western part of India falls under catastrophic to critical non-resilient ecosystem. Soil moisture availability in the biome, forest cover, type of land use, agricultural practices, and climate shocks are mainly influencing the resilience of the anthropogenic biomes in India. The resilience assessment can be used by policymakers to plan anthropogenic interventions in harmony with nature.</p></div>","PeriodicalId":34142,"journal":{"name":"Quaternary Science Advances","volume":"15 ","pages":"Article 100214"},"PeriodicalIF":2.9,"publicationDate":"2024-06-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2666033424000522/pdfft?md5=42b8ca9f40e2f899910a186c1109e6db&pid=1-s2.0-S2666033424000522-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141630292","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"GIS-based MCDM approach for landslide hazard zonation mapping in east Gojjam zone, central Ethiopia","authors":"Chalachew Tesfa,&nbsp;Demeke Sewnet","doi":"10.1016/j.qsa.2024.100210","DOIUrl":"https://doi.org/10.1016/j.qsa.2024.100210","url":null,"abstract":"<div><p>Landslides are prevalent in the Ethiopian highlands, particularly in the east Gojjam zone, which is highly affected by landslide problems. This research was carried out in the east Gojjam zone, northwestern Ethiopia. The study area is part of an economically important area in the country, and it is the main source of water for the Grand Ethiopian Renaissance Dam (GERD). The main objective of this work was to undertake a detailed inventory of past landslide locations and prediction of present and future landslide hazards, as well as the preparation of a landslide zonation map in the East Gojjam zone by using the Analytical Hierarchy Process (AHP) with the GIS technique. The parameters used for this study were slope degree, slope aspect, land use and land cover, road proximity, rainfall, lithology, altitude, and river proximity. The various causative parameters were collected from the field, and suitable modifications were made to the thematic maps. Finally, the ratings for various parameters were used as the basis to prepare the LHZ map in GIS windows. The landslide susceptibility and inventory mapping were produced in the GIS environment. The results of the study show that the main driving factors for the landslide hazards in the area were river proximity, rainfall, and manmade activities. Validation of this LHZ map revealed that more than 80% of past landslides match within the \"high hazard zone\" and reasonably accepted the rationality of the adopted methodology. The considered parameters, as well as their evaluation of the production of LHZ-Map, were confirmed. The produced landslide inventory map is very important for urban planners, agricultural studies, environmentalists, and future landslide hazardous prevention and mitigation strategies.</p></div>","PeriodicalId":34142,"journal":{"name":"Quaternary Science Advances","volume":"15 ","pages":"Article 100210"},"PeriodicalIF":2.9,"publicationDate":"2024-06-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2666033424000480/pdfft?md5=f0fae9362a436ef2d576227832b12a30&pid=1-s2.0-S2666033424000480-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141486624","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"An integrated approach to identify flood hazard and risk areas in Melka Soda district, Southern Ethiopia","authors":"Dechasa Diriba ,&nbsp;Shankar Karuppannan","doi":"10.1016/j.qsa.2024.100211","DOIUrl":"https://doi.org/10.1016/j.qsa.2024.100211","url":null,"abstract":"<div><p>Flooding is a severe meteorological event that can result in fatalities and major economic losses. This study utilizes geographic information system, remote sensing technology, and multi-criteria decision making to create an accurate flood susceptibility map for the Melka Soda district in Southern Ethiopia. Various factors such as normalized difference vegetation index, landuse landcover, soil type, drainage density, slope, rainfall, geology, and elevation were taken into consideration when mapping out areas susceptible to flooding. The results indicate that 7.1%, 16.6%, 20%, 29.9%, and 26.4% of the district are classified as very low, low, moderate, high, and very high hazard zones, respectively. By analyzing population density and land use in conjunction with the flood hazard map, five zones of varying risk levels were identified: very low, low, moderate, high, and very high-risk zones covering 12.4%, 29.5%, 39%, 10.6%, and 7.5% of the district respectively. This showed that 18.1% of the district is classified as having a high to very high level of flood risk. To validate this result, survey data was used to map 28 flood points in the area, and a receiver operating characteristic curve was plotted, resulting in an area under the curve of 86.7%. This confirms the accuracy of the proposed framework, which can assist authorities in creating development policies that consider the current flood risk in the area.</p></div>","PeriodicalId":34142,"journal":{"name":"Quaternary Science Advances","volume":"15 ","pages":"Article 100211"},"PeriodicalIF":2.9,"publicationDate":"2024-06-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2666033424000492/pdfft?md5=339e23fe9634b0bdc528c8d2fa105ab8&pid=1-s2.0-S2666033424000492-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141486623","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Combining orbital tuning and direct dating approaches to age-depth model development for Chew Bahir, Ethiopia","authors":"Martin H. Trauth ,&nbsp;Asfawossen Asrat ,&nbsp;Markus L. Fischer ,&nbsp;Verena Foerster ,&nbsp;Stefanie Kaboth-Bahr ,&nbsp;Henry F. Lamb ,&nbsp;Norbert Marwan ,&nbsp;Helen M. Roberts ,&nbsp;Frank Schaebitz","doi":"10.1016/j.qsa.2024.100208","DOIUrl":"https://doi.org/10.1016/j.qsa.2024.100208","url":null,"abstract":"<div><p>The directly dated <em>RRMarch2021</em> age model (Roberts et al., 2021) for the ∼293 m long composite core from Chew Bahir, southern Ethiopia, has provided a valuable chronology for long-term climate changes in northeastern Africa. However, the age model has limitations on shorter time scales (less than 1–2 precession cycles), especially in the time range &lt;20 kyr BP (kiloyears before present or thousand years before 1950) and between ∼155 and 428 kyr BP. To address those constraints we developed a partially orbitally tuned age model. A comparison with the ODP Site 967 record of the wetness index from the eastern Mediterranean, 3300 km away but connected to the Ethiopian plateau via the River Nile, suggests that the partially orbitally tuned age model offers some advantages compared to the exclusively directly dated age model, with the limitation of the reduced significance of (cross) spectral analysis results of tuned age models in cause-effect studies. The availability of this more detailed age model is a prerequisite for further detailed spatiotemporal correlations of climate variability and its potential impact on the exchange of different populations of <em>Homo sapiens</em> in the region.</p></div>","PeriodicalId":34142,"journal":{"name":"Quaternary Science Advances","volume":"15 ","pages":"Article 100208"},"PeriodicalIF":2.9,"publicationDate":"2024-06-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2666033424000467/pdfft?md5=cff547bb591baa42d86fd2fe14c477d1&pid=1-s2.0-S2666033424000467-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141486553","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Nitrogen uptakes dynamics with environmental variables in the southwest Bay of Bengal","authors":"Kandasamy Priyanka ,&nbsp;Ranjitkumar Sarangi ,&nbsp;Vajravelu Manigandan ,&nbsp;Durairaj Poornima ,&nbsp;Ayyappan Saravanakumar","doi":"10.1016/j.qsa.2024.100213","DOIUrl":"https://doi.org/10.1016/j.qsa.2024.100213","url":null,"abstract":"<div><p>Nitrate uptake is an essential nutrient for primary production. A study focused on the surface waters of the Bay of Bengal (BoB), new, regenerated, and total production were estimated from nitrate, ammonia, and urea (nitrogen uptakes). Understanding nitrogen uptake rates in coastal waters, where nutrient limitations can disturb environmental biological productivity, is essential. A detailed study of these uptake rates and metabolic processes is required to develop effective mitigation strategies to prevent further degradation of these ecosystems. Total production ranged between 1.39 and 7.43 mmol N m² d⁻¹, new production ranged between 0.58 and 2.83 mmol N m² d⁻¹ and regenerated production ranged between 0.83 and 4.59 mmol N m² d⁻¹. The study observed a significant negative correlation nitrogen uptake along with pH, sea surface salinity (SSS), and sea surface temperature (SST) was observed in the study. The R² values for SST were 0.605, 0.619, 0.503, 0.601, and 0.627; for SSS they were 0.688, 0.511, 0.498, 0.579, and 0.644 with nitrogen (Na¹⁵NO₃), ammonium (¹⁵NH₄Cl), urea (CO(¹⁵NH₂)²), regenerated, and total production uptake, respectively. pH was highly correlated with nitrate uptake (R² = 0.525), had a low correlation with ammonium uptake (R² = 0.439) and a moderate correlated with urea uptake (R² = 0.526). A positive relationship of nitrogen uptakes with chlorophyll-a, dissolved oxygen, and dissolved inorganic nitrogen (DIN) were observed. Chlorophyll-a had R² value of 0.608, 0.126, 0.524, 0.526, 0.578, with Na¹⁵NO₃, ¹⁵NH₄Cl, CO(¹⁵NH₂)², regenerated and total production uptake respectively. Dissolved oxygen (DO) related to ammonium uptake showed a very poor correlation (R² = 0.079) but a better correlation with urea (R² = 0.534). New production uptake rate showed a high positive correlation with DO (R² = 0.645), whereas regenerative production uptake rates showed a relatively low correlation (R² = 0.519). The positive relationship between DIN and nitrogen uptake had corresponding R² value of 0.642, 0.591, 0.558, 0.652 and 0.675 for nitrite, ammonium, urea, regenerated and total production uptakes respectively. Total nitrogen: Total phosphate (TN:TP) showed a positive correlation with ammonium. The TN:TP relationship fit nicely with R² = 0.576 (nitrate uptake), 0.524 (ammonium uptake), and 0.503 (urea uptake) in the coastal BoB. Hence, by applying statistical analysis, principal component analysis and pearson correlation, the interdependency of the environmental parameters enhancing the new production has been confirmed.</p></div>","PeriodicalId":34142,"journal":{"name":"Quaternary Science Advances","volume":"15 ","pages":"Article 100213"},"PeriodicalIF":2.9,"publicationDate":"2024-06-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2666033424000510/pdfft?md5=6741ecce1fed290f4d06fb0feb1aaa18&pid=1-s2.0-S2666033424000510-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141438367","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Last interglacial and MIS 9e relative sea-level highstands in the Central Mediterranean: a reappraisal from coastal cave deposits in the Cilento area, Southern Italy","authors":"Ilaria Isola ,&nbsp;Monica Bini ,&nbsp;Andrea Columbu ,&nbsp;Mauro Antonio Di Vito ,&nbsp;Biagio Giaccio ,&nbsp;Hsun-Ming Hu ,&nbsp;Fabio Martini ,&nbsp;Francesca Pasquetti ,&nbsp;Lucia Sarti ,&nbsp;Federica Mulè ,&nbsp;Antonio Mazzoleni ,&nbsp;Chuan-Chou Shen ,&nbsp;Giovanni Zanchetta","doi":"10.1016/j.qsa.2024.100212","DOIUrl":"https://doi.org/10.1016/j.qsa.2024.100212","url":null,"abstract":"<div><p>A revaluation of the relative sea-level (RSL) indicators in the Baia di Infreschi (Cilento, Southern Italy) supported by new 30 U/Th dating on speleothems indicates that the upper level of <em>Lithophaga</em> burrows identified by Bini et al. (2020) at ∼9 m a.s.l. and correlated to the Last Interglacial (LIG) highstand should be referred to the highstand of the MIS 9e, whereas the local RSL for the highstand of the LIG is now reassessed at 5.3 ± 0.18 m a.s.l. The upper level of the <em>Lithophaga</em> marker can be followed for ∼12 km along the coast, suggesting a substantial absence of important relative tectonic movements. In the Baia di Infreschi an additional marine indicator, a notch sealed by a flowstone dated ∼110 ka, indicates several phases of RSL stationing below the maximum highstand of the LIG. The presence of flowstones as low as 2 m a.s.l. dated to the MIS 7 shows that the highstand of MIS 7 was probably below the present sea level. All these evidences allow us to reassess the stratigraphy of some archaeological caves in the area, indicating that the sedimentary successions preserved there are older than what was previously believed.</p></div>","PeriodicalId":34142,"journal":{"name":"Quaternary Science Advances","volume":"15 ","pages":"Article 100212"},"PeriodicalIF":2.9,"publicationDate":"2024-06-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2666033424000509/pdfft?md5=c6d63e701cc0e3a0398e88247c8111ee&pid=1-s2.0-S2666033424000509-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141486622","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Holocene alluvial dynamics, soil erosion and settlement in the uplands of Macedonia (Greece): New geoarchaeological insights from Xerolakkos in Grevena","authors":"Giannis Apostolou ,&nbsp;Alfredo Mayoral ,&nbsp;Konstantina Venieri ,&nbsp;Sofia Dimaki ,&nbsp;Arnau Garcia-Molsosa ,&nbsp;Mercourios Georgiadis ,&nbsp;Hector A. Orengo","doi":"10.1016/j.qsa.2024.100206","DOIUrl":"10.1016/j.qsa.2024.100206","url":null,"abstract":"<div><p>This paper addresses the interplay between Holocene landscape evolution and human settlement dynamics, drawing new evidence from the alluvial history of Xerolakkos, a continental stream in Grevena (Western Macedonia, Greece). We developed an integrated geoarchaeological survey combining remote sensing geomorphological mapping, litho-stratigraphic analysis and radiocarbon dating with the site evidence of a new archaeological survey. Results revealed four major alluviation phases, corresponding to 1) the beginning of the Holocene until the Early Neolithic (∼6300/6200 BCE), 2) the end of the Early and the Middle Neolithic (∼6000–5400 BCE), 3) from the Middle Bronze Age to the Late Roman period (∼1800 BCE – 500 CE), and 4) during the Byzantine and Ottoman eras (∼500–1800 CE), all separated by phases of floodplain incision. Furthermore, the effects of several Holocene Rapid Climatic Changes (RCC) are traced and discussed together with potential human responses; we also provide the first alluvial sequence recording the ∼6200 BCE (8.2 kyr BP) event in the Balkans. While the climate and the local geomorphological setting are considered the primary drivers behind instability and erosion during the Early and Middle Holocene, a landscape change starting in the Middle Bronze Age (after ∼1800 BCE) followed by a re-organisation of the rural economy in the Roman period suggests the increasing involvement of anthropogenic forcing which, by the Ottoman period, evolved into a dynamic situation between climatic variability and adaptive land management. Finally, we demonstrate how soil erosion in the upper catchment constitutes a serious taphonomic bias when studying the regional archaeological record.</p></div>","PeriodicalId":34142,"journal":{"name":"Quaternary Science Advances","volume":"15 ","pages":"Article 100206"},"PeriodicalIF":2.9,"publicationDate":"2024-06-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2666033424000443/pdfft?md5=a52524fdd92c12c5a834ab3e50c53bb7&pid=1-s2.0-S2666033424000443-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141395442","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Integration of geospatial analysis, frequency ratio, and analytical hierarchy process for landslide susceptibility assessment in the maze catchment, omo valley, southern Ethiopia","authors":"Obse Kebeba ,&nbsp;Leulalem Shano ,&nbsp;Yadeta Chemdesa ,&nbsp;Muralitharan Jothimani","doi":"10.1016/j.qsa.2024.100203","DOIUrl":"https://doi.org/10.1016/j.qsa.2024.100203","url":null,"abstract":"<div><p>This investigation was conducted in southern Ethiopia's Maze watershed in the Omo River Valley. Frequency ratio (FR) and analytic hierarchy process (AHP) techniques were used to assess landslide susceptibility in the region. Identifying causative components and landslide inventory data achieved the goal. Remote sensing and on-site investigations found 793 landslide polygons. To assess vulnerability, the landslide inventory information is categorized into two groups: the training dataset (70%) and the validation dataset (30%). This study examined “slope, aspect, curvature, lithology, land use and cover, normalized vegetation index, and proximity to fault lines, rivers, and distance to road as landslide controlling factors”. The spatial analysis capabilities in Arc GIS were used to overlay the weights of all landslide-causing components to create the susceptibility map. A final landslide susceptibility map is produced using FR and AHP methods and categorized as “very low,” “low,” “moderate,” “high,” and “very high.” The frequency ratio method divides the region into susceptibility classes by frequency. The very low, low, medium, high, and very high susceptibility groups cover 25%, 20%, 18%, and 19% of the territory. The analytical hierarchical process technique shows that 3%, 7%, 26%, 36%, and 28% of the area are very low, low, medium, moderate, and very high landslide susceptibility. The receiver operating characteristic curve was employed to validate the area-underlayer susceptibility maps. The success rates were determined using the FR and AHP approaches, resulting in AUC numbers of 0.873 and 0.87. Similarly, the prediction rates were determined to be 0.81 and 0.80. The landslide susceptibility maps will significantly influence land resource allocation.</p></div>","PeriodicalId":34142,"journal":{"name":"Quaternary Science Advances","volume":"15 ","pages":"Article 100203"},"PeriodicalIF":4.5,"publicationDate":"2024-06-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2666033424000418/pdfft?md5=bc7a811795cb2747ae4b8a2c34953eca&pid=1-s2.0-S2666033424000418-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141303559","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Carbon and nitrogen biogeochemistry of a high-altitude Himalayan lake sediment: Inferences for the late Holocene climate","authors":"Abdur Rahman ,&nbsp;Rayees Ahmad Shah ,&nbsp;M.G. Yadava ,&nbsp;Sanjeev Kumar","doi":"10.1016/j.qsa.2024.100199","DOIUrl":"10.1016/j.qsa.2024.100199","url":null,"abstract":"<div><p>A study was conducted to decipher changes in paleoenvironmental conditions of the Kashmir Valley (India) using stable isotopic compositions and elemental concentrations of total organic carbon (TOC) and total nitrogen (TN) in a sediment core from the Wular Lake. The Chronology of the core established through radiocarbon dating estimated the age of the core bottom to be 3752 Cal years BP, covering the late Holocene. Using carbon isotopic compositions of TOC (δ¹³C), nitrogen isotopic compositions of TN (δ¹⁵N), and TOC - TN contents, the study identified changes in biology and associated biogeochemical processes in the Wular Lake during the late Holocene. Changes in C and N biogeochemistry of the lake through the last 3752 Cal years BP suggested overall drier condition during 3752–1500 Cal years BP that transitioned into a wetter condition at around 1500 Cal years BP until at least 295 Cal years BP. Evidence for relatively intense drier events were observed within the dry and wet phases at around 2500 and 500 Cal years BP. Changes in δ¹³C and TOC contents in the sediment core revealed that the inorganic C dynamics and productivity (along with organic C contents) in the lake were largely regulated by variations in respired CO₂ and HCO₃⁻ availability along with terrestrial matter supply through the Jhelum River. Similarly, variations in δ¹⁵N and TN contents showed changes in N dynamics of the lake with varying nitrification and decomposition throughout the studied period. Observed dry and wet phases in the region might be due to the weakening and strengthening of the precipitation, which was linked to negative and positive phases of the North Atlantic Oscillation, respectively.</p></div>","PeriodicalId":34142,"journal":{"name":"Quaternary Science Advances","volume":"14 ","pages":"Article 100199"},"PeriodicalIF":4.5,"publicationDate":"2024-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2666033424000376/pdfft?md5=b464fed9c180015c157dd36646c902a7&pid=1-s2.0-S2666033424000376-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141036221","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}