地球科学最新文献

{"title":"Sources and Emissions of Marine-Derived Halocarbons Over the Coastal and Open Ocean of the Northwest Pacific","authors":"Shan-Shan Liu,&nbsp;Yi-Ning Bai,&nbsp;Jie Ni,&nbsp;Zhen He,&nbsp;Gui-Peng Yang","doi":"10.1029/2024JD042706","DOIUrl":"https://doi.org/10.1029/2024JD042706","url":null,"abstract":"<p>The spatial variability and sources of atmospheric methyl halides (CH₃Cl, CH₃Br, and CH₃I) over the northwest Pacific and its marginal seas—the East China Sea (ECS) and South China Sea (SCS)—were comprehensively characterized from 2017 to 2020. This study represents the first large-scale investigation of these compounds across coastal and open-ocean environments. Atmospheric CH₃Cl and CH₃Br concentrations were substantially elevated in the ECS and SCS, exceeding Northern Hemisphere background levels by 12%–28%, whereas concentration enhancements over the northwest Pacific were 3%–5%. Elevated CH₃Cl and CH₃Br concentrations were attributed to long-range terrestrial atmospheric transport from China, Korea, Japan, and the Philippines, as well as localized phytoplankton-driven production in nutrient-rich coastal waters. In contrast, CH₃I concentrations were primarily controlled by photochemical processes mediated by dissolved organic carbon (DOC), with elevated levels being observed in the oligotrophic subtropical northwest Pacific (10°–30°N). Multiple regression analyses revealed that CH₃Cl and CH₃Br distributions were mainly influenced by terrestrial transport in coastal areas, whereas oceanic processes dominated their distributions in the open ocean. CH₃I distributions primarily reflected oceanic photochemical production, with marginal terrestrial influence limited to the ECS. The production rates of CH₃Br and CH₃Cl in the ECS and SCS, respectively, were 2–3 times higher than those in the northwest Pacific, consistent with enhanced biological activity. Sea-to-air flux estimates demonstrated that the northwest Pacific and its marginal seas acted as net sources of all three methyl halides, with fluxes generally exceeding global averages by approximately 1.5–48 times. These findings underscore the importance of the study area to the atmospheric methyl halides budget.</p>","PeriodicalId":15986,"journal":{"name":"Journal of Geophysical Research: Atmospheres","volume":"130 11","pages":""},"PeriodicalIF":3.8,"publicationDate":"2025-06-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144232338","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Measuring cluster interactions through in-between areas in epidemic spatiotemporal dynamics","authors":"Fei-Ying Kuo ,&nbsp;Tzai-Hung Wen","doi":"10.1016/j.apgeog.2025.103688","DOIUrl":"10.1016/j.apgeog.2025.103688","url":null,"abstract":"<div><div>Understanding interactions between spatiotemporal clusters is essential for effective epidemic control. Cluster interaction occurs when a location belongs to multiple clusters at different times, indicating spatial but not temporal overlap. However, such overlap alone does not fully explain how clusters are linked or how transmission pathways form across them. Analytical frameworks to examine these dynamics remain limited. This study introduces the concept of “in-between areas”, transitional zones, that connect clusters through shared transmission routes. We propose a novel framework that integrates causal analysis with network community detection to identify clusters, detect in-between areas, and quantify their interactions. Applied to the 2014 dengue outbreak in Kaohsiung, Taiwan, the results reveal that in-between areas shift from administrative boundaries to interior districts as the epidemic progresses, indicating evolving cluster interactions. These areas link locations across different clusters, exposing the complex structure of spatial diffusion. Quantitative findings show that dominant clusters often absorb smaller ones, with the latter frequently initiating transmission into new regions. The proposed framework identifies both the timing and spatial configuration of cluster interactions, offering new insights into epidemic spread. This approach advances spatial epidemiology by supporting the design of targeted, mobility-aware public health interventions.</div></div>","PeriodicalId":48396,"journal":{"name":"Applied Geography","volume":"181 ","pages":"Article 103688"},"PeriodicalIF":4.0,"publicationDate":"2025-06-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144229821","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Daphnia‐associated bacterial communities correlate with diet quantity, environmental conditions, and epidemic size across natural outbreaks","authors":"Amruta Rajarajan, Justyna Wolinska, Jean‐Claude Walser, Nadine Tardent, Silvana Käser, Esther Keller, Piet Spaak","doi":"10.1002/lno.70103","DOIUrl":"https://doi.org/10.1002/lno.70103","url":null,"abstract":"Zooplankton‐associated microbiomes play an important role for host health, and contribute to ecosystem processes such as nutrient cycling. Yet, few studies have assessed how environmental gradients and biotic interactions, including parasitism and diet, may shape the microbiome composition of wild zooplankton. Here, we analyzed the microbiomes of water fleas from the <jats:italic>Daphnia longispina</jats:italic> species complex using 16S rRNA gene sequencing and a long‐term field dataset spanning six sampling events over 13 years. Sampling coincided with outbreaks of the virulent eukaryotic gut parasite <jats:italic>Caullerya mesnili</jats:italic>. Additionally, we explored how microbiome structure varied in relation to water parameters, phytoplankton density (i.e., <jats:italic>Daphnia</jats:italic> diet), and zooplankton density and community structure. <jats:italic>Daphnia</jats:italic> microbiomes displayed strong temporal variation and comparatively small differences based on host infection status. Microbiome beta diversity correlated with phytoplankton density but not with its community composition, including green algae, protists, and cyanobacteria. Environmental conditions, including temperature, dissolved oxygen, and cyanobacterial abundance—previously found to drive <jats:italic>Caullerya</jats:italic> epidemics—were also associated with distinct microbiome structures. Importantly, microbiome beta diversity co‐varied with infection prevalence, suggesting a link between microbiome shifts, epidemic size, and environmental conditions driving large epidemics. Dominant bacterial taxa correlated with <jats:italic>Daphnia</jats:italic> density, whereas the phylogenetic composition of rare taxa was associated with total zooplankton density. These findings demonstrate the dynamic nature of <jats:italic>Daphnia</jats:italic> microbiomes and suggest potential mechanisms by which they may mediate disease dynamics, particularly through associations with diet quantity, temperature, and host population density.","PeriodicalId":18143,"journal":{"name":"Limnology and Oceanography","volume":"42 1","pages":""},"PeriodicalIF":4.5,"publicationDate":"2025-06-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144237158","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":"Isotopic identification of paleo rift zones within the Sveconorwegian Province; implications for nickel sulphide mineralisations in the SW Fennoscandian Shield","authors":"Alf Andre Orvik,&nbsp;Eduardo T. Mansur,&nbsp;Iain Henderson,&nbsp;Trond Slagstad,&nbsp;Magdalena Huyskens,&nbsp;Terje Bjerkgård","doi":"10.1016/j.precamres.2025.107836","DOIUrl":"10.1016/j.precamres.2025.107836","url":null,"abstract":"<div><div>The southwestern Fennoscandian Shield hosts significant orthomagmatic nickel sulphide deposits linked to pre-Sveconorwegian crustal evolution. This study integrates new U-Pb zircon geochronology, Lu-Hf isotopic data, and whole-rock geochemistry from the Kongsberg Unit of the Sveconorwegian Province to investigate its magmatic and metallogenetic evolution. The results reveal distinct magmatic episodes across the three complexes of the Kongsberg Unit, highlighting notable temporal and isotopic heterogeneity. Magmatism in the Eastern Kongsberg Complex is confined between 1610 ± 11 and 1524 ± 11 Ma, coeval with igneous activity during the Gothian orogeny and consistent with an arc-related tectonic setting. Meanwhile, the Western Kongsberg Complex records younger, more juvenile magmatism between 1528 ± 9 and 1153 ± 3 Ma. In contrast, the intervening Modum Complex represents extensional basin development with sedimentation &lt; 1475 Ma and juvenile mafic magmatism between 1305 ± 8 Ma and 1185 ± 12 Ma. Nickel sulphide mineralisation, including the Ertelien (1584 ± 19 Ma) and Langedal (1546 ± 2 to 1524 ± 11 Ma) deposits in the Eastern Kongsberg Complex, predominantly correlates with Gothian magmatism, whereas deposits in the Western Kongsberg Complex, such as Grågalten (1164 ± 13 Ma), are linked to later magmatic events. A pronounced westward-younging trend in zircon U-Pb crystallisation ages and Hf model ages supports a dynamic lithospheric evolution driven by long-lived crustal extension and subsequent Sveconorwegian orogenic assembly. Additionally, widespread platinum group element (PGE) depletion across the province suggests a pyroxenitic mantle source, rather than repeated sulphide extraction during magmatic differentiation. These findings emphasise the critical role of pre-Sveconorwegian lithospheric architecture and mantle source characteristics in controlling nickel sulphide mineralisation, offering valuable insights for future exploration strategies in the region.</div></div>","PeriodicalId":49674,"journal":{"name":"Precambrian Research","volume":"427 ","pages":"Article 107836"},"PeriodicalIF":3.2,"publicationDate":"2025-06-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144229515","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Widespread and Exceptional Reduction in River Water Levels Across the Amazon Basin During the 2023 Extreme Drought Revealed by Satellite Altimetry and SWOT","authors":"Daniel Moreira,&nbsp;Fabrice Papa,&nbsp;Alice Fassoni-Andrade,&nbsp;Ayan Fleischmann,&nbsp;Sly Wongchuig,&nbsp;Rodrigo Paiva,&nbsp;Adrien Paris,&nbsp;Frederic Frappart,&nbsp;Jefferson Melo,&nbsp;Jean-Francois Crétaux,&nbsp;André Martinelli Santos,&nbsp;Pierre-André Garambois,&nbsp;Benjamin Kitambo,&nbsp;Stéphane Calmant","doi":"10.1029/2025GL116180","DOIUrl":"https://doi.org/10.1029/2025GL116180","url":null,"abstract":"<p>In late 2023, the Amazon River Basin experienced its most extreme drought to date, putting its population and ecosystem at risk. Gauges that were still functioning measured the lowest river water levels (RWL) on record. Here, satellite observations, including Surface Water Ocean Topography (SWOT), reveal the spread and timing of extremely low RWL across the entire river system. The majority of Nadir altimeter observations show that the 2023 minimum RWL in the Central Amazon were 3 m or more below their annual average, representing two to three times its mean variability. Additionally, SWOT captures the basin-scale reduction in RWL with a spatial resolution of 200 m and how it propagates with time. Large-scale evaluation with gauges suggests that SWOT outperforms classical altimetry in estimating RWL, despites differences that need further investigations. SWOT offers a new opportunity to understand hydroclimatic extremes and their broad impacts on the environment of the Amazon.</p>","PeriodicalId":12523,"journal":{"name":"Geophysical Research Letters","volume":"52 11","pages":""},"PeriodicalIF":4.6,"publicationDate":"2025-06-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2025GL116180","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144220408","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Quantifying tidal zonation through pollen-microfacies coupling: A Holocene sea-level proxy from Hangzhou Bay, eastern China","authors":"Xiaoyu Zhang ,&nbsp;Yan Liu ,&nbsp;Jinqi Dai ,&nbsp;Li Xiao ,&nbsp;Xiaolong Chen ,&nbsp;Xueming Li ,&nbsp;Jing Chen ,&nbsp;Maotian Li ,&nbsp;Qianli Sun ,&nbsp;Lingyu Tang","doi":"10.1016/j.quascirev.2025.109466","DOIUrl":"10.1016/j.quascirev.2025.109466","url":null,"abstract":"<div><div>Accelerating sea-level rise necessitates high-resolution paleoenvironmental proxies to refine future projections. Mid-Holocene analogs remain critical for coastal vulnerability assessments, yet microfacies-based reconstructions are constrained by limited diagnostic precision in sedimentary archives. Here, we address this gap through systematic analysis of modern vegetation zonation and pollen transport dynamics across tidal flat transects in South Hangzhou Bay, eastern China. Results demonstrate that pollen distributions encode quantifiable tidal elevation signals: (1) Allochthonous <em>Pinus</em> pollen dominates unvegetated lower intertidal zones and <em>Spartina alterniflora</em>-sparse middle flats, exhibiting an inverse relationship with elevation; (2) Autochthonous Chenopodiaceae and <em>Taraxacum</em> pollens show strong positive elevational dependencies, peaking in upper intertidal marshes and supratidal terrestrial interfaces; (3) Poaceae pollen lacks diagnostic value due to dual airborne/hydrodynamic transport pathways, producing homogenized distributions across tidal zones. We propose <em>Pinus</em> depletion trends and Chenopodiaceae enrichment thresholds as discrete elevational markers for reconstructing Holocene relative sea-level (RSL) index points. This work establishes pollen as a high-resolution proxy capable of resolving previously unrecognized tidal zonation patterns, thereby advancing the spatiotemporal precision of post-glacial RSL reconstructions in coastal systems.</div></div>","PeriodicalId":20926,"journal":{"name":"Quaternary Science Reviews","volume":"364 ","pages":"Article 109466"},"PeriodicalIF":3.2,"publicationDate":"2025-06-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144223244","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":"A virtual coastal band-driven optimization-based bathymetric approach (VOBA) for optically shallow water with multispectral imagery","authors":"Yongming Liu, Shilin Tang, Bin Cao, Zhantang Xu, Xulong Liu, Kai Zeng, Yuye Huang, Wendi Zheng","doi":"10.1080/15481603.2025.2506191","DOIUrl":"https://doi.org/10.1080/15481603.2025.2506191","url":null,"abstract":"","PeriodicalId":55091,"journal":{"name":"GIScience & Remote Sensing","volume":"21 1","pages":""},"PeriodicalIF":6.7,"publicationDate":"2025-06-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144237248","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Absolute Environmental Sustainability Assessment of the Arid Central Asia by Downscaling Planetary Boundaries","authors":"Ziyang Zhu,&nbsp;Meiqing Feng,&nbsp;Yaning Chen,&nbsp;Weili Duan,&nbsp;Zhi Li,&nbsp;Wim Cornelis,&nbsp;Philippe De Maeyer","doi":"10.1029/2025EF006129","DOIUrl":"https://doi.org/10.1029/2025EF006129","url":null,"abstract":"<p>Assessing absolute environmental sustainability (AES) is essential to ensure that human activities remain within a safe operating space. However, it remains unclear whether the planetary boundaries (PBs) have been breached in Central Asia. This study analyzed environmental pressures in arid Central Asia from 2000 to 2020 by downscaling PBs and evaluating AES ratios. Environmental distance was applied to identify environmental surpluses or overshoots, while an integrated environmental sustainability index (IESI) was to identify priority management areas. Domestic consumption dominated the environmental footprint during 2000–2020. Besides land footprint, water, carbon, nitrogen, phosphorus and human appropriation of net primary production to Central Asia were mainly from Europe and Asia. Kazakhstan and Uzbekistan were identified as IESI level III, becoming priority management areas for sustainable development. Improving resource utilization efficiency and strengthening trade cooperation can strengthen the PBs of arid Central Asia and promote sustainable environmental development.</p>","PeriodicalId":48748,"journal":{"name":"Earths Future","volume":"13 6","pages":""},"PeriodicalIF":7.3,"publicationDate":"2025-06-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2025EF006129","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144219981","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effects of Solar Flares on the Ionosphere of Mars: Comparison of Observed and Predicted Electron Density Profiles From 15 to 26 April 2001","authors":"Paul Withers,&nbsp;A. G. Cramer,&nbsp;D. J. Pawlowski","doi":"10.1029/2024JA033197","DOIUrl":"https://doi.org/10.1029/2024JA033197","url":null,"abstract":"<p>Solar flares significantly affect Mars's ionosphere, yet there are few comparisons between observed and simulated densities in the M1 and M2 ionospheric layers during solar flares. Here we compare observed and simulated electron density profiles for the X14.4 solar flare of 15 April 2001 and the M7.8 solar flare of 26 April 2001. We use observations from Mars Global Surveyor radio occultations and simulations from the Mars Global Ionosphere-Thermosphere Model (M-GITM). Due to poor constraints on the solar spectrum incident upon Mars at this time, simulated M2 electron density values were 50% larger than observed. Yet the relative changes in M2 electron density during these two flares were reproduced to 10% accuracy. When accurate solar irradiance data are available, absolute M2 electron density values are simulated accurately. Due to the omission of electron impact ionization from the M-GITM model, the simulated M1/M2 density ratio was under-predicted by a factor of approximately 3. Yet the relative changes in M1 electron density during these two flares were reproduced to 20% accuracy. The model can accurately predict relative changes in M1 and M2 electron densities during a solar flare. If accurate solar irradiance data are available, it can accurately predict absolute changes in M2 electron densities. If a simple parameterization of electron impact ionization were incorporated into the model, then it would likely predict absolute changes in M1 electron densities accurately as well. The M-GITM model is well-suited to studies of time-varying phenomena in the ionosphere of Mars.</p>","PeriodicalId":15894,"journal":{"name":"Journal of Geophysical Research: Space Physics","volume":"130 6","pages":""},"PeriodicalIF":2.6,"publicationDate":"2025-06-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144220346","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"FTIR spectra combined with machine learning to reveal the amber trade during the Han dynasty (202 BCE–220 CE)","authors":"Xingping Li ,&nbsp;Liduo Long ,&nbsp;Yixuan Wang ,&nbsp;Qi Liu ,&nbsp;Bin Chen ,&nbsp;Qinghui Li","doi":"10.1016/j.jas.2025.106268","DOIUrl":"10.1016/j.jas.2025.106268","url":null,"abstract":"<div><div>Amber has long been recognized as a key to providing vital insights into the commercial exchanges of ancient civilizations. This study analyzed fifty amber beads from Southern China (Guangdong Province), fifteen from Northwestern China (Qinghai Province), and thirteen from Central China (Hunan Province) during the Han dynasty to trace their origins by Attenuated Total Reflection Fourier Transform Infrared (ATR-FTIR) and Diffuse Reflectance Infrared Spectroscopy (DRIFTS). An automated amber origin classification method was proposed to verify the manually identified amber origin and streamline the analysis. The factors influenced by post-depositional alterations, including impurities, degrees of aging, and testing methods, show no correlation with amber origin, which may diminish classification effectiveness. Each of these factors was examined individually, leading to the identification of credible origin fingerprint peaks in the IR spectra. Valid data processing steps focused on fingerprint peaks’ regions were designed based on the IR spectra features. Density-based spatial clustering of application with noise (DBSCAN) was adopted to discover groups within the data. Classification models were then created using Support Vector Machine (SVM), Decision Tree (DT), and K-Nearest Neighbor (KNN) algorithms. The machine learning (ML) models demonstrated high accuracy comparable to manual identification while also achieving greater efficiency. According to the manual and ML results, the prevalence of both Baltic and Burmese amber in Guangdong and Hunan and the mainstream of Baltic amber in Qinghai were discussed, along with the potential amber trade routes. Our results provided evidence for the vibrant exchange between China, Southeast Asia, Southern Asia, and Central Asia in the Han dynasty and indirect trade links from the Han Empire to ancient Europe.</div></div>","PeriodicalId":50254,"journal":{"name":"Journal of Archaeological Science","volume":"180 ","pages":"Article 106268"},"PeriodicalIF":2.6,"publicationDate":"2025-06-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144222890","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}