Marine Geology最新文献

{"title":"Quantitative structural geology in the deep ocean using photogrammetry: Implications for the polyphased tectonic evolution of the Buteur Ridge, French Guiana","authors":"Charline Coudun ,&nbsp;Paul Brichard ,&nbsp;Christophe Basile ,&nbsp;Sébastien Zaragosi ,&nbsp;Vincent Marieu ,&nbsp;Martin Patriat ,&nbsp;Lies Loncke","doi":"10.1016/j.margeo.2025.107609","DOIUrl":"10.1016/j.margeo.2025.107609","url":null,"abstract":"<div><div>The Buteur Ridge is a 7 km-long and 6 km-wide relief on the eastern rifted margin of the Demerara Plateau, offshore French Guiana. This margin was formed during the Lower Cretaceous. In early 2023, the oceanographic cruise DIADEM used a manned deep submersible (<em>Nautile</em>) to sample and directly observe the eastern flank of this 3750 m-deep ridge.</div><div>This study presents a new underwater photogrammetric method developed from the <em>Nautile</em> video records. This method incorporates both camera and submarine movements to produce photogrammetric 3D models of the seafloor below decimetre scale. The presented underwater photogrammetric method can be used for both past and future video records, as long as both underwater device and camera movements are recorded.</div><div>The data obtained from the 3D reconstructions allow to reconstruct detailed stratigraphic and structural framework of the Buteur Ridge. The eastern flank of the Buteur Ridge is entirely composed of sedimentary layers. Structural analysis at bed scale suggests prograding structures likely associated with a N-S-directed paleocurrent. At ridge scale, structural analysis combined with seismic observations suggests that the Buteur Ridge is the result of a polyphased tectonic evolution. We highlight that Cretaceous tilted blocks, bounded by east-dipping faults, are overlapped by a post-rift unit. The syn-rift units are in contact with the east-dipping post-rift unit by a post-rift unconformity. Subsequent tilt and fault reactivation offset both the post-rift unconformity and the post-rift unit, resulting in the present relief of the Buteur Ridge.</div></div>","PeriodicalId":18229,"journal":{"name":"Marine Geology","volume":"488 ","pages":"Article 107609"},"PeriodicalIF":2.6,"publicationDate":"2025-06-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144502505","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Rapid retreat of marsh-edge cliffs, Jiangsu coast, China","authors":"Yunwei Wang ,&nbsp;Yali Qi ,&nbsp;Qian Yu","doi":"10.1016/j.margeo.2025.107606","DOIUrl":"10.1016/j.margeo.2025.107606","url":null,"abstract":"<div><div>Coastal salt marshes are an essential part of the ecosystem, but they are threatened by marsh-edge cliff retreat. Using satellite remote sensing and field data from 2013 to 2017, this study investigates the exceptionally high retreat rates of marsh-edge cliffs along the central Jiangsu coast of China, averaging 24.6 m/a (range: 7.3–39.2 m/a), which are an order of magnitude higher than typical global values. We examine the temporal and spatial patterns of cliff retreat and explore the mechanisms driving these rapid changes. Previous studies have widely considered wave power as the primary driver of marsh-edge retreat; however, this study shows that it cannot fully explain the observed rates. We identify two key factors contributing to the rapid retreat: (1) the open tidal flat environment, where strong tidal and coastal currents transport eroded sediment away, hindering sediment replenishment, and (2) the relatively tall marsh-edge cliffs with a substantial mesotidal range (∼3.4 m), which are more susceptible to erosion through cantilever failure and slumping. These findings highlight the complex interplay of environmental factors driving marsh degradation and suggest that future research should incorporate high-temporal-resolution monitoring to better capture the nature of cliff erosion, especially with increasing changes in climate condition globally.</div></div>","PeriodicalId":18229,"journal":{"name":"Marine Geology","volume":"488 ","pages":"Article 107606"},"PeriodicalIF":2.6,"publicationDate":"2025-06-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144329936","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Coral reef boulders as recorders of cyclone activity over the last 3500 years (Fakarava Atoll, Tuamotu, French Polynesia)","authors":"Lucien F. Montaggioni ,&nbsp;Bernard Salvat ,&nbsp;Éric Brunaud ,&nbsp;Edwige Pons-Branchu ,&nbsp;Gilbert Poli ,&nbsp;Bertrand Martin-Garin","doi":"10.1016/j.margeo.2025.107605","DOIUrl":"10.1016/j.margeo.2025.107605","url":null,"abstract":"<div><div>Extreme marine hazard events are expected to increase in the next future as a response to global warming. Estimating their frequency and magnitude in the recent past is of prime concern to better project their future impacts. In tropical reef provinces, coral boulders deposited on reef top surfaces can be used as key proxies for defining the occurrence – recurrence time and effects of paleo-storms. The present study defines origin, morphometry, location, orientation, timing and mode of deposition of a number of coral reef boulders present on reef-flats surfaces, along the south-eastern rim areas of Fakarava Atoll, north-west Tuamotu, central South Pacific. These boulders, extracted from the upper forereef spurs, were projected onto the reef-flat zone, at distances of 51 to 235 m from the outer reef edge. Among the 44 described boulders &gt;20 m³, only 19 were revealed to be covered by well-preserved coral colonies in growth position and as such, were submitted to physical analysis and U/Th dating. Upper reef spurs have been built from about 5000 to 3000 cal. yr BP. Dominantly platy in shape, with sharp broken, lateral faces, the 19 investigated boulders range between 3 and 8.5 m long, 4 and 82 m³ in volume, 6.8 to 139.4 tons in weight. The minimum flow velocities to initially move and uplifted these blocks were estimated between about 4 to &gt;13 m/s. Morphometric comparison of the boulder set investigated at Fakarava with those from nearby atolls recognized as cyclone-moved strongly suggests that boulder detachment and deposition at Fakarava have resulted from cyclogenesis than tsunamigenic impacts. Contrary to cyclone-related boulder deposition that appears to have occurred mainly during the last centuries in the nearby atolls, U/Th dating of boulders at Fakarava reveals that cyclogenesis has increased between 3400 and 2300 cal. yr BP (15th–4th centuries BC) and between 2,000 and 1,700 cal. yr BP (1st–4th centuries AD) in the considered region, with an expected mean reccurrence time of around 30 to 50 years. This intensification of cyclone activity is interpreted as related to amplified <span>enso</span> phases in the south Pacific.</div></div>","PeriodicalId":18229,"journal":{"name":"Marine Geology","volume":"488 ","pages":"Article 107605"},"PeriodicalIF":2.6,"publicationDate":"2025-06-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144296967","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Morphologically adaptive modelling of sea level rise induced coastal erosion impacts for south-east Australia","authors":"Robert Jak McCarroll ,&nbsp;David M. Kennedy ,&nbsp;Daniel Ierodiaconou","doi":"10.1016/j.margeo.2025.107602","DOIUrl":"10.1016/j.margeo.2025.107602","url":null,"abstract":"<div><div>Sea level rise induced coastal erosion represents an impending threat to the world's coastlines. A critical control on coastal recession is the onshore accommodation space available for a receding beach to occupy. Despite the importance of morphologic controls, coastal change models applied at regional-scale over ∼100-year time-frames typically address a limited range of coastal morphologies.</div><div>ShoreTrans is a shoreface translation model that kinematically projects profile change, based on inputs of sea level rise and sediment budget imbalances. This work presents updates to enable broad-scale model application (1000's km), automating classification and adapting to the morphology of individual profiles, including: (1) dunes; (2) cliffs; (3) bluffs and ridges; (4) inter-subtidal rock outcrops; (5) protection structures; (6) low-energy environments; and (7) short-term dune erosion. The model was applied to Victoria, Australia (2000 km coastline, 30 m spaced transects), for a scenario of 1 m sea level rise from 2010 to 2100, using a single time step and simplified treatment of uncertainty and sediment budget. Shoreline trends and variability were determined from satellite extracted shorelines.</div><div>Mean projected shoreline recession of 43 m is 20 % lower than for a simple parameterization (uncertainty range 58 % lower to 8 % higher), due to sediment transfer from the backshore to the active shoreface (e.g., dune encroachment) and hard backshores restricting shoreline movements (e.g., cliffs, seawalls). Low dunes exhibited the highest recession rates, due to rollover (68 m long-term recession). Total setback extent, including short-term variability, is projected to exceed 182 m in 5 % of low dune areas. High rates of beach loss were associated with beaches fronting hard cliffs (55 % beach loss) and seawalls (80 %). The worst impacts are expected for rocky, sediment poor coastlines, such as the Great Ocean Road Surf Coast, where a loss of 30 % to 50 % of beaches is projected, not accounting for infrastructure and potential management interventions.</div><div>Automated morphological adaptation represents a step-change for regional scale coastal change assessment. The method also allows for coupling of future erosion to inundation hazards, by interpolating a 3D surface of future morphology. At local-scale, ShoreTrans is suitable to add to hybrid models, providing a means to improve future coastal change projections.</div></div>","PeriodicalId":18229,"journal":{"name":"Marine Geology","volume":"488 ","pages":"Article 107602"},"PeriodicalIF":2.6,"publicationDate":"2025-06-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144535433","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Falkland/Malvinas Trough: Indications for Cenozoic tectonic and oceanographic evolution in the southwestern South Atlantic","authors":"B. Najjarifarizhendi,&nbsp;G. Uenzelmann-Neben,&nbsp;J. Gruetzner","doi":"10.1016/j.margeo.2025.107595","DOIUrl":"10.1016/j.margeo.2025.107595","url":null,"abstract":"<div><div>The Falkland/Malvinas Trough (F/MT) bounds the southern extremity of the Falkland/Malvinas Plateau. This Cenozoic bathymetric depression developed as the orogenic foreland basin of the North Scotia Ridge. The sedimentary infill of the F/MT carries a history of development in a transpressional setting along the South American-Scotian Plate boundary, in association with the evolution of the Drake Passage-Scotia Sea zone. Since the F/MT is located on the pathway of the Antarctic Circumpolar Current, the current-controlled depositional and erosional features within its sedimentary infill provide valuable information on the palaeoceanographic modifications in the southwestern South Atlantic. Via a set of 2D high-resolution seismic reflection data, the structural and morphological features of these strata are investigated and discussed with respect to the tectonic evolution of the Drake Passage-Scotia Sea zone. Evidence of fold structures and normal faulting during Oligocene to mid-Miocene times in the study area argue for a transpressional regime linked with the development of the Drake Passage-Scotia Sea zone. The current-related depositional and erosional processes in the F/MT started between Oligocene to early Miocene times. With the full opening of the Drake Passage, the evolution of the Scotia Sea and the demise of the Ancestral South Sandwich Arc by the mid-Miocene, an oceanographic setting analogous to the present would have established. Evidences suggests that since then, with the enhancement of the abyssal circulation subsequent to the perennial Antarctic glaciation, a precursor of the Weddell Sea Deep Water has been circulating the F/MT, shaping a confined sediment drift deposit.</div></div>","PeriodicalId":18229,"journal":{"name":"Marine Geology","volume":"488 ","pages":"Article 107595"},"PeriodicalIF":2.6,"publicationDate":"2025-06-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144280056","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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 recently identified mass-transport deposit stack in the Guaymas Basin, Gulf of California (México), and its implication in the basin tectonics","authors":"A. Piña ,&nbsp;J. Stock ,&nbsp;D. Lizarralde ,&nbsp;S. Hart ,&nbsp;K. Marsaglia ,&nbsp;C. Gallegos-Castillo ,&nbsp;C. Berndt ,&nbsp;A. González-Fernández ,&nbsp;C. Mortera-Gutiérrez ,&nbsp;A. Martín-Barajas","doi":"10.1016/j.margeo.2025.107592","DOIUrl":"10.1016/j.margeo.2025.107592","url":null,"abstract":"<div><div>A large mass transport deposit (MTD) stack has been identified in the Guaymas Basin using seventeen high-resolution seismic reflection profiles and sediment core analysis. Guaymas Basin is a young, marginal basin characterized by active seafloor spreading in the central Gulf of California, Mexico. The large stack includes five distinct MTD units of variable thickness, area, and volume, characterized by a predominantly transparent seismic reflection facies with small sections of laterally discontinuous reflectors and bumpy upper and erosional lower surfaces. Based on analysis of sediment cores from Site U1551A from International Ocean Discovery Program Expedition 385, we define MTD lithofacies and use sand provenance to infer that the MTD stack originated from the Yaqui Delta region of the Sonoran margin, transporting material to the south-west. We suggest that a combination of high sedimentation rates and active tectonics contributed to the MTD events. ‘Flower structures’ observed in margin-crossing profiles indicate that the MTD stack buried a part of the transform fault separating the Guaymas Basin and the continental Sonoran margin. Seismic reflection interpretations suggest that part of the MTD stack filled the southern graben applying local stresses that drove a change of the sediment surface expression of plate spreading in the sediment-filled basin. In response to the MTD emplacement and the southern graben fill, an additional northern seafloor graben in the Guaymas Basin developed. Our results contribute to the understanding of the interactions among high sedimentation rates, continental slope stability, and active tectonics; and the influence of those interactions on the surface expression of plate spreading in the Guaymas Basin.</div></div>","PeriodicalId":18229,"journal":{"name":"Marine Geology","volume":"488 ","pages":"Article 107592"},"PeriodicalIF":2.6,"publicationDate":"2025-06-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144322793","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Impacts of climate change on the morphodynamics of embayed beaches along the Central West Coast of India","authors":"Puneet Kumar Mishra ,&nbsp;R. Mani Murali ,&nbsp;Deepika Dwivedi ,&nbsp;S.K. Ariful Hossain ,&nbsp;S. Santhosh Kumar ,&nbsp;Shincy Francis ,&nbsp;Richa Rai","doi":"10.1016/j.margeo.2025.107590","DOIUrl":"10.1016/j.margeo.2025.107590","url":null,"abstract":"<div><div>This study investigates the morphodynamics and climatic influences on twenty-seven embayed beaches along the central west coast of India utilizing a comprehensive framework that combines in-situ field observations and remote sensing. These coastal features were classified for the first time using an embayment morphometric parameter (γe) derived from the embayment area (Ae) and indentation (a). This method enabled the categorization of the embayments into three distinct classes - Class 1 (open/exposed), Class 2 (semi-exposed), and Class 3 (Semi-closed/sheltered). Field measurements of beach profiles were conducted for sixteen accessible embayed beaches, focusing on seasonal and annual volumetric changes. The results showed a significant reduction in beach volume from February to September, likely caused by strong monsoonal waves, with partial recovery observed from September to February. To study long-term changes, we analyzed changes in area over three decades (1990–2023) using satellite images. This analysis revealed a maximum erosion of 81.72 m at Mirya and maximum accretion of 62.5 m at Undi, while Net Shoreline Movement (NSM) trends reveal that eight embayments, including Palshet, Hedavi, and Vengurla, are undergoing critical shoreline retreat. Various climate factors, including rising sea levels, increased frequency of cyclones, wave power, and swells, were analyzed to track the causes. The results indicated an increase in regional sea levels, cyclone activity, and wave power, which corresponded with the observed erosion patterns along the central west coast of India. Anthropogenic impacts were also noted,the construction of breakwaters and jetties has caused significant alterations. This study highlights, how human interventions can disrupt natural coastal processes. A key finding of the study is that embayments, which appear stable on seasonal and annual timescales, are dynamic and unstable over the decadal scale.</div></div>","PeriodicalId":18229,"journal":{"name":"Marine Geology","volume":"487 ","pages":"Article 107590"},"PeriodicalIF":2.6,"publicationDate":"2025-05-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144204095","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Estimation of turbidite source area in late Pleistocene to Holocene around Kikai Island based on mineral and biogenic calcium carbonate composition","authors":"Ryo Nakanishi ,&nbsp;Ayumi Maeda ,&nbsp;Atsuko Amano ,&nbsp;Juichiro Ashi ,&nbsp;Asuka Yamaguchi ,&nbsp;Yusuke Yokoyama ,&nbsp;Yosuke Miyairi","doi":"10.1016/j.margeo.2025.107593","DOIUrl":"10.1016/j.margeo.2025.107593","url":null,"abstract":"<div><div>Identifying the initial location of a turbidity current can help reveal a paleogeography, potential petroleum reservoir rocks, and a paleoseismic history. Therefore, a method for estimating the source area of turbidites is crucial. This study estimates the source area of turbidites using marine core sediments and surface sediments obtained around Kikai Island, located in the central Ryukyu Arc. We focus especially on mineral composition, variations of grain-size distribution and microfossil assemblages to estimate the water depth and hinterland geology of the source sand. Calcareous turbidites exhibiting normal grading or laminated structures were identified in the marine core at the fore-arc slope. We compare the calcium carbonate mineral compositions of these calcareous turbidites with those of surface sediments by X-ray diffraction (XRD) analysis. The proportion of aragonite and magnesium calcite, as opposed to calcite, decreases with increasing water depth, corresponding to the habitat of foraminifera and pteropods. A regression equation was obtained from the calcium carbonate mineral ratio and water depth. The predicted water depth of the turbidite source was equivalent to that based on benthic/planktonic foraminiferal ratios. In addition, principal component analysis of XRD results and grain size analysis spatially constrained the source area of turbidites by comparison with surface sediments in the hinterland geology. Since turbidite deposition was limited to 14.7–9.7 ka, we interpret that increased sediment supply resulting from coral-reef drowning during rapid sea-level rise, and calcareous sand beds were unstable and transported by turbidity currents. The method developed in this study provides a framework for estimating the supply source of turbidites and is expected to be used in paleoseismic studies and petroleum reservoir evaluation.</div></div>","PeriodicalId":18229,"journal":{"name":"Marine Geology","volume":"487 ","pages":"Article 107593"},"PeriodicalIF":2.6,"publicationDate":"2025-05-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144204094","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Controls of paleosedimentary environments and anthropogenic activities on coastal groundwater salinization: A case study of Laizhou Bay, China","authors":"Zhen Cui ,&nbsp;Guangquan Chen ,&nbsp;Xin Shan ,&nbsp;Haitao Zhang ,&nbsp;Qingjie Zhou ,&nbsp;Tengfei Fu ,&nbsp;Hongjun Yu ,&nbsp;Xingyong Xu ,&nbsp;Shenliang Chen","doi":"10.1016/j.margeo.2025.107594","DOIUrl":"10.1016/j.margeo.2025.107594","url":null,"abstract":"<div><div>Groundwater salinization presents a substantial environmental challenge for coastal regions globally, particularly along the southern shore of Laizhou Bay. The processes contributing to groundwater salinization are intricate and involve interactions between natural factors and human activities. This study examines the mechanisms underlying groundwater salinization at varying depths in the southern Laizhou Bay area, with a particular emphasis on the effects of extensive groundwater extraction. Excessive groundwater extraction has intensified salinization by altering hydraulic gradients and promoting seawater intrusion. Utilizing sediment and pore water samples from two boreholes (SG100 and WF80) alongside shallow seismic data, we identified that sedimentary strata consisting of alternating marine and terrestrial deposits, formed during multiple transgressive events since the Late Pleistocene, are a significant source of salinity. Paleoenvironmental reconstructions based on grain size analysis, combined with Cl/Br ratios and stable isotope analysis, indicated that modern seawater intrusion is a primary driver of shallow groundwater salinization. In contrast, variations in deep groundwater salinity reflect differing paleoenvironmental recharge conditions. Ancient riverbed sediments exhibit high permeability, providing an efficient pathway for the transport of water and salts from upstream freshwater bodies. This process facilitates the dilution within the aquifer, leading to the formation of low-salinity groundwater. In contrast, the low permeability of floodplain sediments significantly restricts the renewal capacity of water bodies. As a result, the saline water layer maintains a high salinity state over extended periods due to the combined effects of evaporation and limited recharge. Notably, offshore freshwater was detected within ancient river channel deposits. These findings underscore the intricate interplay between sedimentary evolution and anthropogenic activities in influencing groundwater salinization, highlighting the necessity for scientifically informed, water-type-specific management strategies.</div></div>","PeriodicalId":18229,"journal":{"name":"Marine Geology","volume":"487 ","pages":"Article 107594"},"PeriodicalIF":2.6,"publicationDate":"2025-05-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144196389","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Particulate organic carbon dynamics off the Yellow River Estuary revealed by in-situ hydrodynamics and carbon isotopes","authors":"Taian Lu ,&nbsp;Thomas S. Bianchi ,&nbsp;Naishuang Bi ,&nbsp;Xiao Wu ,&nbsp;Shuai Cong ,&nbsp;Jinya Xu ,&nbsp;Xiaoyan Ning ,&nbsp;Houjie Wang","doi":"10.1016/j.margeo.2025.107591","DOIUrl":"10.1016/j.margeo.2025.107591","url":null,"abstract":"<div><div>The Land-to-Ocean-Aquatic-Continuum (LOAC) is a key component in global carbon cycle and budget. Delivery of organic carbon (OC) along the LOAC is impacted by coastal hydrodynamics on a variety of spatial-temporal scales. Here we provide a coupled analysis of suspended particulate OC (POC) transport and hydrodynamics in the Yellow River Estuary. Pre-aged soil POC has become the dominant component (40–50 %) in the river-estuary continuum during the flood season. Petrogenic POC, with high proportion in the river (31 %), experienced drastic deposition off the estuary due to entrapment by shear fronts and estuarine circulation, decreasing to 19–23 %. The terrestrial OC was mainly exported offshore along with the seaward extension of river plume during ebb tide, while could be pushed landward by intruding seawaters during flood tide. When the tidal effects were removed, the first-order net POC residual flux was ∼19 g/m/s in seaward direction in the near-field plume, with dominance of pre-aged soil POC at ∼8 g/m/s and petrogenic POC at ∼6 g/m/s; on the contrary, POC fluxes displayed a landward direction and decreased by two orders of magnitude in the far-field plume. Trapped by shear fronts and estuarine circulation, POC was mostly limited and temporally preserved off the river mouth during the flood season. These findings suggest that intra-tidal estuarine hydrodynamics can further influence the sources, composition, and transport of terrestrial POC, playing a significant role in regulating carbon cycling along the Land-to-Ocean-Aquatic-Continuum.</div></div>","PeriodicalId":18229,"journal":{"name":"Marine Geology","volume":"487 ","pages":"Article 107591"},"PeriodicalIF":2.6,"publicationDate":"2025-05-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144196386","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}