Geoscience frontiers最新文献

{"title":"Lacustrine organic carbon burial dynamics regulate Aptian-Albian greenhouse-cooling climate oscillations","authors":"Dongjun Song ,&nbsp;Yifeng Hong ,&nbsp;Jingyu Zhang ,&nbsp;Xinnan Fang ,&nbsp;Shuang Dai","doi":"10.1016/j.gsf.2025.102150","DOIUrl":"10.1016/j.gsf.2025.102150","url":null,"abstract":"<div><div>Investigating terrestrial response to typical greenhouse periods is essential to understand past and present climate-carbon-cycle interactions. The Cretaceous climate transition is thought to be related to carbon cycles, yet the role of lacustrine systems in modulating global carbon-climate feedback remains poorly constrained. Here, we present a high-resolution biogeochemical record from an Aptian-Albian paleolake in northwestern China, integrating biomarkers, nitrogen isotopes, and elemental proxies. We reveal that warm-humid climates during the early Aptian amplified lacustrine organic carbon burial via intensified denitrification, methane cycling, and nutrient fluxes, potentially reinforcing oceanic anoxic event 1a (OAE1a) hyperthermal conditions through N₂O/CH₄ emissions. Subsequent nitrogen limitation triggered cyanobacterial dominance, sustaining carbon sequestration under moderate weathering and contributing to cooling the late Aptian climate. A transient early Albian warming phase shifted the nitrogen pool towards NH₄⁺ and favored the bloom of eukaryotic algae, aligning with global OAE1b carbon burial and serving as one of the contributors to the late early Albian cooling climate. These dynamics demonstrate that paleolakes acted as both carbon sinks and greenhouse gas sources, exerting a critical but previously overlooked feedback on Cretaceous climate oscillations. Our findings highlight the dual role of lacustrine systems in past carbon cycle perturbations, offering insights for refining the relationships between the carbon cycle and climate changes in the Cretaceous.</div></div>","PeriodicalId":12711,"journal":{"name":"Geoscience frontiers","volume":"16 6","pages":"Article 102150"},"PeriodicalIF":8.9,"publicationDate":"2025-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145105642","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Spatiotemporal analysis of the FWI over Europe and North Africa: Historical trends and climate projections under RCP4.5 and RCP8.5","authors":"Fabio Di Nunno,&nbsp;Francesco Granata","doi":"10.1016/j.gsf.2025.102178","DOIUrl":"10.1016/j.gsf.2025.102178","url":null,"abstract":"<div><div>Wildfires represent an escalating environmental threat across Europe and North Africa, increasingly exacerbated by climate-driven shifts in temperature, precipitation, and drought patterns. However, there is still limited large-scale, methodologically consistent research that simultaneously assesses historical patterns and future projections of fire danger across these regions, particularly in terms of both frequency and duration of risk under different climate scenarios. This study addresses this gap by providing a high-resolution, spatiotemporal assessment of fire weather conditions, with the aim of offering critical insights to support climate-adaptive fire management strategies, extended preparedness frameworks, and the integration of future fire weather projections into land-use and risk governance policies. To achieve this, we investigate historical (1979–2021) and projected (2000–2098) trends in fire danger using the Canadian Fire Weather Index (FWI), based on ERA5 reanalysis data and outputs from five Global Climate Models (GCMs) under RCP4.5 and RCP8.5 scenarios. Over 50,000 land grid cells were analyzed to assess the frequency and duration of six FWI danger classes. Different metrics were used to quantify the agreement between historical reanalysis data and GCM outputs, while the Seasonal Kendall (SK) test was applied to detect trends. Results reveal a substantial decline in the duration of the very low FWI class, from 36 to 23 months, and significant increases in both the duration and frequency of the extreme FWI class, reaching up to 6.38 months and 14.42% under the RCP8.5 scenario. Correlation coefficients exceed 0.8 across much of Southern Europe and North Africa, indicating strong temporal agreement. Trend analyses reveal statistically significant increases in fire danger across southern latitudes, while Northern Europe shows mixed or decreasing trends. These findings project a dramatic intensification and expansion of fire-prone conditions, particularly under high-emission scenarios.</div></div>","PeriodicalId":12711,"journal":{"name":"Geoscience frontiers","volume":"16 6","pages":"Article 102178"},"PeriodicalIF":8.9,"publicationDate":"2025-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145332899","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The evolution of lithium resources and isotopic composition in salt lakes on the Qinghai-Tibet Plateau: A source–transport–sink perspective","authors":"Hualing Song ,&nbsp;Qishun Fan ,&nbsp;Jianping Wang ,&nbsp;Jiansen Li ,&nbsp;Zhiyong Ling ,&nbsp;Jinjun Han ,&nbsp;Chuntao Zhao ,&nbsp;Tianli Wang ,&nbsp;Jiao Yu","doi":"10.1016/j.gsf.2025.102156","DOIUrl":"10.1016/j.gsf.2025.102156","url":null,"abstract":"<div><div>The source–transport–sink dynamics of salt lakes are fundamentally tied to resource source and mineralization, which are crucial for sustainable resource development and environmental protection. By integrating published and experimental datasets on lithium (Li) concentrations, Li isotopes, and Li/TDS–Li/Na ratios, this study systematically investigates the characteristics, evolutionary patterns, and driving mechanisms of Li and its isotopes throughout source–transport–sink processes in salt lakes across the Qinghai–Tibet Plateau. The results demonstrate that: (1) Li in salt lakes primarily originates from geothermal fluids, with significant contributions from Li-rich rocks and paleosediments. (2) Li transport mechanisms can be classified into source- and process-control. In source-control systems, Li is largely derived from Li-rich endmembers; although secondary inputs and attenuation occur during transport, the persistently high dissolved Li load governed by the original source retains a diagnostically traceable isotopic composition. This system is marked by high dissolved Li fluxes (&gt;300 μg/L), elevated Li × 10³/TDS ratios (&gt;0.7), and relatively depleted <em>δ</em>⁷Li values (1 ‰ to 6 ‰, occasionally as low as −4.8 ‰). In process-control systems, Li mainly comes from silicate weathering within catchments, resulting in lower riverine Li fluxes (20–80 μg/L) that are highly sensitive to environmental conditions, where source signals are frequently overprinted by secondary inputs and adsorption. These systems exhibit lower Li × 10³/TDS ratios (0.05–0.22) and enriched <em>δ</em>⁷Li values ranging from 6 ‰ to 18 ‰. (3) The sink evolution of Li and its isotopes is controlled by clay adsorption and evaporite precipitation, closely correlating with developmental phases of salt lake. Clay adsorption causes Li depletion and isotopic fractionation, leading to elevated <em>δ</em>⁷Li signatures in the early evolutionary phase. In later phases, evaporate becomes the dominant control on brine Li isotope evolution due to evaporite formed aquicludes, reduced adsorption capacity of ancient clays, and suppression of adsorption under high salinity. (4) This study offers valuable references for understanding Cenozoic marine Li isotope evolution by establishing a source–transport–sink framework within a small sink basin. Tectonic uplift has enhanced continental weathering and physical erosion, increasing supplies of dissolved Li and fresh clay minerals in runoff, while climate change has reduced continental discharge and extended water–rock interaction time. These processes collectively enhance water–rock interactions through increased reactant supply and prolonged reaction duration, elevating riverine <em>δ</em>⁷Li fluxes into the ocean and influencing marine Li isotope evolution.</div></div>","PeriodicalId":12711,"journal":{"name":"Geoscience frontiers","volume":"16 6","pages":"Article 102156"},"PeriodicalIF":8.9,"publicationDate":"2025-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145216981","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Disentangling relative controls of landscape evolution and spatial heterogeneity in the Vaigai River Basin, southern India: Regional implications and applicability","authors":"K.J. Juni ,&nbsp;M. Ramkumar ,&nbsp;B. Venkateshwaran ,&nbsp;D. Menier ,&nbsp;M.J. Mathew ,&nbsp;K. Balasubramani ,&nbsp;N.A. Siddiqui","doi":"10.1016/j.gsf.2025.102128","DOIUrl":"10.1016/j.gsf.2025.102128","url":null,"abstract":"<div><div>Deciphering tectono-climatic-lithological and other controls over landscape evolution at variable spatiotemporal scales is paramount in natural resources management and development. We have systematically documented and analysed selected critical quantitative morphometric data, namely, asymmetry factor, hypsometric integral, hypsometric curve, drainage divide migration and normalised steepness index, in addition to the assessment of longitudinal profiles and knickpoints, for a unique morphological river basin, the Vaigai River Basin, located in southern India. The spatial variability of various controls of geomorphological characteristics of the basin is interpreted using these morphometric parameters and field data. Notable results include, predominance of a concave-up nature of the majority of the sub-basins, occurrence of a distinct convex zone in the upper part and a distinctly concave zone in the lower part of the basin, a range of symmetric to asymmetric topographic nature with very prominent asymmetry in the middle of the basin, highest normalised channel steepness in the northernmost sub-basin and insignificant and lesser steepness in the majority of the basin, evidence of north-easterly migration of drainage divides within the river basin, manifested by sub-basin boundaries and the alignment of the majority of the knickpoints parallel to the NE–SW trending Karur-Kambam-Painavu-Thrissur shear zone. The results cumulatively indicate that the Vaigai River that runs on an antecedent basin continues evolving, principally under the controls of regional Precambrian structures. Nevertheless, the evolution has been episodic and spatially varied. The resurgent tectonic influence is more pronounced in the northern and north-western parts of the basin, while the river capture and drainage divide migration are pronounced in the northeastern part, signifying the collective influence of tectonics and climate. On the contrary, the middle and lower reaches of the basin lack a soil-sediment-weathered zone, signifying the prevalence of an intense erosional phase of the river. This information, together with previously documented catastrophic flooding events and sediment accumulation, categorise the river basin as episodically active, and in a transient phase of evolution. While providing affirmative evidence for the previous regional geomorphological model, the interpretation of the continuum of inherited Precambrian structures in the present study implies that there are subtle spatial differences of lithological-climatological and structural controls within and among each of the sub-basins that need to be considered for any natural resources management at local to regional scales.</div></div>","PeriodicalId":12711,"journal":{"name":"Geoscience frontiers","volume":"16 6","pages":"Article 102128"},"PeriodicalIF":8.9,"publicationDate":"2025-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144886946","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The causal links between green energy, uncertainty, remittances, FDI, and ecological footprint: Evidence using structural breaks and multiple wavelet approach","authors":"Brayan Tillaguango ,&nbsp;Rafael Alvarado ,&nbsp;Abdul Rehman ,&nbsp;Cem Işık ,&nbsp;Muntasir Murshed","doi":"10.1016/j.gsf.2025.102131","DOIUrl":"10.1016/j.gsf.2025.102131","url":null,"abstract":"<div><div>Policies encouraging green energy adoption promote environmental sustainability, particularly in developing countries where the remittances boost household consumption. This research aims to empirically examine the impact of green energy, output, uncertainty, remittances, and Foreign Direct Investment (FDI) on the ecological footprint in Ecuador during 1990–2023. The research contributes to the green energy-environmental sustainability nexus debate by capturing the effect of external and internal shocks in the series and assessing the time–frequency dimension. This research is pioneering in examining the causal relationship between green energy, the uncertainty index, and the ecological footprint using combined cointegration and the multiple wavelet approach in the context of a remittance-dependent country. Notably, cointegration techniques with structural breaks, long-run elasticities using Dynamic Ordinary Least Square (DOLS), Fully Modified Ordinary Least Square (FMOLS), and Canonical Cointegrating Regression (CCR) models, partial and multiple wavelet analysis, and Fourier causality are used for estimation purposes. Accordingly, the results confirm cointegrating relationships in the presence of structural breaks among green energy, GDP, uncertainty, remittances, FDI, and environmental sustainability. Besides, it is found that output and uncertainty increase the ecological footprint, while remittances, FDI, and green energy reduce it. Hence, policymakers should consider remittances, FDI, and green energy as mechanisms to achieve Sustainable Development Goals (SDG) agenda so that environmental sustainability can be promoted in Ecuador.</div></div>","PeriodicalId":12711,"journal":{"name":"Geoscience frontiers","volume":"16 6","pages":"Article 102131"},"PeriodicalIF":8.9,"publicationDate":"2025-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144916926","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Shale oil occurrence and mobility mechanisms in brittle mineral-enriched reservoirs: Insights from the Paleogene Kongdian Formation, Bohai Bay Basin","authors":"Bixiao Xin ,&nbsp;Fang Hao ,&nbsp;Jinqiang Tian ,&nbsp;Pengfei Guo ,&nbsp;Qilu Xu ,&nbsp;Wenzhong Han","doi":"10.1016/j.gsf.2025.102149","DOIUrl":"10.1016/j.gsf.2025.102149","url":null,"abstract":"<div><div>Understanding shale oil occurrence and mobility is essential for evaluating resource potential and optimizing exploration in lacustrine shale systems. This study investigates the Paleogene Kongdian Formation in the Bohai Bay Basin, integrating organic geochemistry, mineralogical analysis, scanning electron microscopy, solvent extraction, multi-step Rock-Eval pyrolysis, and 2-D NMR to characterize shale oil occurrence states and mobility mechanisms in brittle mineral-enriched reservoirs. Results indicate that shale oil mainly occurs in free and adsorbed states within interparticle pores, dissolution pores, microfractures, and organic pores, with most retained oil hosted in nanopores smaller than 200 nm. Quantitative analyses show that siliceous and calcareous shales possess higher movable oil ratios than clay-rich counterparts, primarily due to their rigid mineral frameworks that resist compaction and preserve interparticle and intragranular pores. These brittle-rich lithofacies exhibit broader pore size distributions, enhanced connectivity, and reduced adsorption affinity, facilitating more efficient oil accumulation and displacement. In contrast, micropore-dominated, clay-rich shales exhibit strong adsorption and limited pore continuity, which hinder hydrocarbon mobility. Appropriate TOC levels (2.0–4.5 wt.%) favor shale oil mobility, while excessive organic content increases adsorption, reducing the proportion of free oil.</div><div>Among various geological factors, brittle mineral content and thermal maturity play the dominant roles in controlling shale oil mobility, as they fundamentally shape pore structure and fluid properties. In combination with organic matter abundance and sedimentary features, these factors jointly govern pore network evolution and hydrocarbon occurrence states, thereby determining shale oil enrichment and extractability. These findings enhance the understanding of shale oil enrichment processes and provide a scientific basis for identifying sweet spots and optimizing development strategies in lacustrine shale reservoirs.</div></div>","PeriodicalId":12711,"journal":{"name":"Geoscience frontiers","volume":"16 6","pages":"Article 102149"},"PeriodicalIF":8.9,"publicationDate":"2025-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145154544","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Hydrochemistry and multi-isotopes for interpreting formation mechanisms of different-type geothermal waters in the Cuona-Woka Rift, southern Tibetan Plateau","authors":"Xingcheng Yuan ,&nbsp;Yunhui Zhang ,&nbsp;Jinhang Huang ,&nbsp;Zhonghe Pang ,&nbsp;Haoqing Huang ,&nbsp;Weibing Wang ,&nbsp;Ying Wang ,&nbsp;Ming Chang ,&nbsp;Marco Taussi ,&nbsp;Lisheng Wang","doi":"10.1016/j.gsf.2025.102170","DOIUrl":"10.1016/j.gsf.2025.102170","url":null,"abstract":"<div><div>High-temperature geothermal activities are widely distributed in rift tectonic zones, where significant volumes of geothermal waters with diverse hydrochemical characteristics are exposed. However, it is still unclear whether these geothermal waters have different formation mechanisms, which hinders the efficient exploitation and utilization of geothermal resources. Hence, this study investigates 41 geothermal water samples from the Cuona-Woka Rift (CWR) on the Tibetan Plateau to elucidate their hydrogeochemical evolutions and formation mechanisms. These geothermal waters are distributed along normal faults (N–S) and thrust faults (E–W), with discharge temperatures ranging from 34.0 to 85.5 °C. Self-organizing map classification identifies three distinct hydrochemical groups: Group 1 (Cl-Na and Cl·HCO₃-Na), Group 2 (HCO₃·Cl-Na), and Group 3 (SO₄·Cl-Ca·Na). The <em>δ</em>D and <em>δ</em>¹⁸O values indicate that meteoric and snow-melt waters are the dominant recharge sources for geothermal waters, with magmatic water contributions ranging from 18 % to 24 % (Group 1) and 12 % to 21 % (Group 2). The hydrochemical composition is primarily controlled by silicate and carbonate mineral dissolution, gypsum leaching, and cation exchange, with a higher contribution rate than the mixing of magmatic waters. All geothermal waters originate from the same deep sources, with Groups 2 and 3 undergoing mixing with 68 %–88 % and 57 %–70 % shallow cold groundwater, respectively. The significantly enriched trace alkali elements (Li, Rb, and Cs) in Group 1 are attributed to the input of crustal magma melts. Deep reservoir temperatures are estimated at 251–270 °C (Group 1), 226–229 °C (Group 2), and 189–194 °C (Group 3) based on empirical chemical geothermometers, silica-enthalpy mixing model, and geothermometric modeling. The maximum circulation depths are 4.8–5.2 km, 4.3–4.4 km, and 3.5–3.6 km, respectively. Three genesis conceptual models controlled by rift structures are proposed: melt intrusion heating type, hot–cold mixing heating type, and steam heating type. These findings will enhance the understanding of the origin of rift-type geothermal waters and provide valuable insights for the global exploitation and utilization of high-temperature geothermal resources.</div></div>","PeriodicalId":12711,"journal":{"name":"Geoscience frontiers","volume":"16 6","pages":"Article 102170"},"PeriodicalIF":8.9,"publicationDate":"2025-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145332900","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Craton boundary detection from full-waveform tomography model reveals links to critical metal deposits","authors":"Hojat Shirmard ,&nbsp;Ben Mather ,&nbsp;Ehsan Farahbakhsh ,&nbsp;Karol Czarnota ,&nbsp;R. Dietmar Müller","doi":"10.1016/j.gsf.2025.102176","DOIUrl":"10.1016/j.gsf.2025.102176","url":null,"abstract":"<div><div>Craton margins play a crucial role in mineral exploration as they host faults, fractures, and shear zones that facilitate hydrothermal fluid movement, transporting and depositing dissolved metals into valuable mineral deposits. We use the high-resolution full-waveform seismic inversion model REVEAL to extract horizontal shear wave velocity (<em>V</em>_SH), vertical shear wave velocity (<em>V</em>_SV), and isotropic P-wave velocity (<em>V</em>_P) across depth slices from 150 to 200 km, a range that captures most cratonic lithosphere based on tectonic age and lithospheric thickness analyses. Machine learning, applied through clustered maps, demonstrates that <em>V</em>_SH effectively delineates craton boundaries, aligning with target mineral deposits, including iron oxide copper–gold (IOCG) and sediment-hosted lead, zinc, and copper deposits. These boundaries are characterized by high horizontal shear velocities (4.58–4.68 km/s), and trace the edges of cratons, accreted passive margins, orogens, and thick volcanic arcs. Using published thermal and lithospheric thickness models, we distinguish cratons from other thick lithospheric features and identify their edges and associated deposits. Our results show that ∼85 % of the total metal content (Cu + Pb + Zn) in target deposits lies within ∼120 km of high-velocity cluster boundaries identified as craton edges. Near-craton deposits reveal ∼80 % of the total metal content within ∼90 km of craton boundaries. The weighted cumulative distribution function shows a steeper gradient in metal content closer to craton boundaries, indicating higher concentrations near these tectonic features. Focusing on just 16 % of Earth’s continental areas can reveal over 80 % of known target deposits, highlighting the significance of craton boundaries quantitatively mapped in this study.</div></div>","PeriodicalId":12711,"journal":{"name":"Geoscience frontiers","volume":"16 6","pages":"Article 102176"},"PeriodicalIF":8.9,"publicationDate":"2025-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145266530","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Strategic use of Sentinel-3A/B OLCI data for global water quality management: An overview","authors":"Emanuelle Goellner ,&nbsp;Brian William Bodah ,&nbsp;Alcindo Neckel ,&nbsp;Paloma Carollo Toscan ,&nbsp;Júlia Mognol Scopel ,&nbsp;Cleiton Korcelski ,&nbsp;Guilherme Peterle Schmitz ,&nbsp;Giana Mores ,&nbsp;Marcos L.S. Oliveira ,&nbsp;Eduardo Nuno Borges Pereira","doi":"10.1016/j.gsf.2025.102175","DOIUrl":"10.1016/j.gsf.2025.102175","url":null,"abstract":"<div><div>The Sentinel-3A/B satellites, operated by the European Space Agency (ESA), are equipped with the Ocean and Land Color Instrument (OLCI), which provides data through push-broom radiometers. Sentinel-3A was launched on February 16, 2016, and Sentinel-3B on April 25, 2018. Given their relevance in environmental monitoring, there is a growing need for literature reviews to deepen the functional understanding of their geospatial applications. This study aims to review the scientific literature on using Sentinel-3A/B OLCI data for monitoring aquatic environments, particularly focusing on chlorophyll-a (CHL), total suspended matter (TSM), and absorption of dissolved organic matter at 443 nm (ADG443). The review includes publications indexed in the Scopus and Web of Science (SCIE) databases between February 2016 and 2025. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) methodology was employed to select 26 relevant studies that apply spectral detections via Sentinel-3A/B satellites related to levels of CHL, TSM, and ADG443. Additionally, the Content Analysis Method (CAM) and MAXQDA software were used to analyze absolute (AF) and relative frequencies (RF) of key variables such as study location, sampling, objectives, use of Sentinel satellites, outcomes, innovations, and future research directions. CAM results showed an average frequency of ∼ 36.0%, with Sentinel-3A accounting for 35.3% and Sentinel-3B ranging between 31.89% and 40.08%. Chlorophyll-a was the most frequently cited term, with a frequency of 32.33% to 40.08% in MAXQDA. The consistency and reliability of spectral detections underscore the potential of these satellites to support the aquatic ecosystem preservation.</div></div>","PeriodicalId":12711,"journal":{"name":"Geoscience frontiers","volume":"16 6","pages":"Article 102175"},"PeriodicalIF":8.9,"publicationDate":"2025-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145266531","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Extreme drought affects lake water quality, quantity, morphometry: Evidence from China’s largest fresh water lake under the 2022 global drought","authors":"Xihua Wang ,&nbsp;Zejun Liu ,&nbsp;Y. Jun Xu ,&nbsp;Boyang Mao ,&nbsp;Shunqing Jia","doi":"10.1016/j.gsf.2025.102146","DOIUrl":"10.1016/j.gsf.2025.102146","url":null,"abstract":"<div><div>Extreme drought poses a significant threat to humanity. In the summer of 2022, the world experienced the worst drought in recent years, with a precipitation deficit and an abnormal high temperature, profoundly affecting human life and the aquatic environment. However, the drought influence on large freshwater lakes remains unclear. In this study, we selected China’s largest freshwater lake (Poyang Lake) as the research object and investigated the lake water area, quantity, lake morphology and water quality in 2018 (normal season) and 2022 (extreme drought period). Results showed that standardized precipitation index (SPI), standardized runoff index (SRI) and standardized precipitation-evapotranspiration index (SPEI) reached moderate to severe drought in the summer of 2022. From 2018 to 2022, lake water area decreased (1789.62 km²), water quantity reduced (15.40 × 10⁹ m³) and lake shoreline decreased (2923.70 km). The shoreline development index, size ratio and energy factor decreased by 4.87, 198.53 m and 963.60, specifically. The dynamic ratio, relative depth and Schindler’s ratio increased by 1457.10, 0.04 and 13.48 m⁻¹, respectively. The water chemical indicators varied significantly in two years and the water hydrochemical types changed from SO₄·Cl − Ca·Mg type and HCO₃ − Ca·Mg type to SO₄·Cl − Ca·Mg type from 2018 to 2022. Water-rock interaction, alternating cation adsorption and anthropogenic influence on water quality represented different patterns in two periods. Our findings demonstrate significant differences in water resources and quality between common and extreme drought conditions in China’s largest fresh water lake, which can inform research on climate change effects on international large freshwater lakes.</div></div>","PeriodicalId":12711,"journal":{"name":"Geoscience frontiers","volume":"16 6","pages":"Article 102146"},"PeriodicalIF":8.9,"publicationDate":"2025-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145060209","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}