Quaternary Science Advances最新文献

{"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}

{"title":"Modeling terminal Pleistocene and Holocene forager population increase and environmental change in the Central Namib desert, Namibia","authors":"Grant S. McCall ,&nbsp;Theodore P. Marks","doi":"10.1016/j.qsa.2024.100202","DOIUrl":"https://doi.org/10.1016/j.qsa.2024.100202","url":null,"abstract":"<div><p>This paper examines the interplay of environmental change and human demographic shifts among late Pleistocene and Holocene populations in the hyper-arid context of the Central Namib Gravel plains, Western Namibia. This paper applies a structural equation modeling (SEM) approach to arid-zone hunter-gatherer mobility patterns and settlement systems based on variability among ethnographically and historically observed groups. It then applies this model in examining issues related to the Middle-to-Later Stone Age transition at the sites of Erb Tanks and the Mirabib rock shelter. This model suggests that, among modern arid-zone foragers, population density is by far the strongest factor influencing mobility and settlement systems, with higher population densities favoring longer residential site usages and shorter residential moves within smaller territories. In contrast, environmental variables having to do with annual rainfall, rainfall seasonality, and effective temperature affect mobility and settlement systems in ambiguous and statistically insignificant ways. This paper closes by arguing that regional-scale population increases signaled by various features of Later Stone Age archaeological patterning led to local population expansions in the Central Namib Desert, and that this in turn caused a range of recognizable cultural shifts that were strongly linked with adaptations to aridity.</p></div>","PeriodicalId":34142,"journal":{"name":"Quaternary Science Advances","volume":"15 ","pages":"Article 100202"},"PeriodicalIF":4.5,"publicationDate":"2024-05-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2666033424000406/pdfft?md5=e233f1c34372c5f9c708d940e0d74f9e&pid=1-s2.0-S2666033424000406-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141250349","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":"Low variability of authigenic 10Be/9Be across the Holocene Po plain parasequences reveals suitability of dating method for highstand deltaic deposits","authors":"Kishan Aherwar ,&nbsp;Michal Šujan ,&nbsp;Alessandro Amorosi ,&nbsp;Bruno Campo ,&nbsp;Andrej Chyba ,&nbsp;Adam Tomašových ,&nbsp;Barbara Rózsová ,&nbsp;Aster Team ,&nbsp;Régis Braucher","doi":"10.1016/j.qsa.2024.100201","DOIUrl":"https://doi.org/10.1016/j.qsa.2024.100201","url":null,"abstract":"<div><p>The authigenic ¹⁰Be/⁹Be dating method presents a valuable tool for reconstructing depositional chronologies in sedimentary environments, requiring only ubiquitous mud for sampling. Nevertheless, studies elucidating the variability of the ¹⁰Be/⁹Be record preserved in epicontinental successions are lacking, despite the essential nature of such knowledge for the application of authigenic ¹⁰Be/⁹Be in geochronology. In this study, we investigate the variability of measured natural ¹⁰Be/⁹Be ratios in sediment cores recovered from the Holocene Po River delta plain in Northern Italy, aiming to unveil the influence of changing sedimentary environments and provenance on the beryllium isotopic signature. We identified significant variations in the authigenic ¹⁰Be/⁹Be ratios across parasequences, which correlates with a provenance change from the Eastern Alps to the Po River. The observed variation would cause an age offset of ∼1 Myr if unrecognized in a dated succession. Our analysis revealed consistent ratios between the delta plain (primarily represented by swamp) and delta front consisting of proximal prodelta facies, suggesting a prevalent riverine signature in the proximal prodelta, likely maintained by hyperpycnal flow deposition. Statistical assessments based on random sampling and bootstrapping highlighted the importance of a sample size of n &gt; 10. Furthermore, a standard deviation of the observed variability indicates a necessity of an additional 9% uncertainty in authigenic ¹⁰Be/⁹Be dating studies if the sample size is smaller. Overall, our findings emphasize that the normal regressive highstand settings of a deltaic system maintain relatively stable beryllium isotopic fluxes, which are favourable for the authigenic ¹⁰Be/⁹Be dating application, if provenance changes are known.</p></div>","PeriodicalId":34142,"journal":{"name":"Quaternary Science Advances","volume":"15 ","pages":"Article 100201"},"PeriodicalIF":4.5,"publicationDate":"2024-05-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S266603342400039X/pdfft?md5=a4676dd472c3fdfcb7d9840b9d19099e&pid=1-s2.0-S266603342400039X-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141303561","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":"Estimation of surface deformation in Sikkim and Eastern Nepal Himalaya using PSInSAR technique","authors":"Raj Sunil Kandregula ,&nbsp;Pavankumar G ,&nbsp;Ajay Manglik ,&nbsp;Girish Ch Kothyari","doi":"10.1016/j.qsa.2024.100200","DOIUrl":"https://doi.org/10.1016/j.qsa.2024.100200","url":null,"abstract":"<div><p>The region of the Himalayan arc covering Sikkim and eastern Nepal experiences dominant strike-slip deformation oblique to the convergence direction of the Indian plate. This region is also traversed by transverse structural and tectonic features. The present study is aimed at comprehending the horizontal and vertical deformation rates for this region using the PSInSAR technique. We utilized 70 and 78 Single Look Complex images in ascending and descending passes respectively, spanning from February 2017 to August 2023 for time-series displacement measurement along the radar line of sight (LOS). The results reveal the LOS velocity ranging from −15 to +10 mm/yr for the ascending data and ±20 mm/yr for the descending data. The mean line-of-sight velocities of ascending and descending passes were decomposed to estimate the horizontal (east-west) and vertical components of the deformation vector. These components range from ±15 mm/yr and −12 to +8 mm/yr, respectively, suggesting that the horizontal deformation predominates in the study area. A NW-SE trending boundary coinciding with the Tista lineament sub-divides the study region into the eastern Nepal and the Sikkim blocks based on the patterns of the deformation rates. The eastern Nepal block south of the Main Central Thrust exhibits locked portion of the arc with eastward motion, whereas the Sikkim block exhibits uplift (unlocked with creep) and westward motion. The amplitudes of these deformation rates support dominant strike-slip deformation with minor vertical deformation component. These results suggest that the Tista lineament is a prominent strike-slip fault and probably the most significant active tectonic feature in the region. Together with the seismicity data, we infer that probably the entire crustal block rather than the Himalayan wedge is contributing to the surface deformation, as mapped by the present PSInSAR study.</p></div>","PeriodicalId":34142,"journal":{"name":"Quaternary Science Advances","volume":"14 ","pages":"Article 100200"},"PeriodicalIF":4.5,"publicationDate":"2024-05-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2666033424000388/pdfft?md5=e64190b6f491c0ca1b132fffd5990735&pid=1-s2.0-S2666033424000388-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141156329","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}