Shoreline progradation in enclosed basins such as the Caspian Sea—driven by climate-induced hydrological change—poses unique challenges for coastal prediction, as most existing models were developed for water-level rise and open-coast dynamics. The original Bruun rule assumes a closed sediment budget and therefore tends to overpredict shoreline advance under falling water levels, overlooking the offshore loss of finer sediment fractions. To address this gap, the study introduces a new index, the Compatibility Index (CI), and integrates it into the Bruun rule, comparing six CI methods across six sandy and two sandy–gravel monitoring stations. While the Bruun rule was originally designed for sandy beaches, its applicability was extended here to mixed sand–gravel profiles. A practical decision framework—combining acceptable CI ranges from three prioritized methods and local bed slope—identifies an optimal CI (CIO) for each station. Shoreline change from 2013 to 2022 was tracked using cross-shore profiles and high-resolution satellite imagery. Incorporating the CIO into the Bruun rule reduced root mean square error from 61.3 m to 21.4 m, mean absolute error from 49.0 m to 16.6 m, and mean bias error from 49.0 m to 14.6 m, improving prediction accuracy by 73.2%. The resulting model delivers robust, site-specific shoreline forecasts and provides a practical tool for coastal managers planning setback zones or adaptation strategies in enclosed-basin environments, while offering a transferable framework for similar settings worldwide.
{"title":"Integrating the Bruun rule with sediment compatibility analysis for shoreline change evaluation under water level fall","authors":"Hesamodin Enayatighadikolaei , Takayuki Suzuki , Martin Mäll , Mohsen Soltanpour","doi":"10.1016/j.margeo.2025.107701","DOIUrl":"10.1016/j.margeo.2025.107701","url":null,"abstract":"<div><div>Shoreline progradation in enclosed basins such as the Caspian Sea—driven by climate-induced hydrological change—poses unique challenges for coastal prediction, as most existing models were developed for water-level rise and open-coast dynamics. The original Bruun rule assumes a closed sediment budget and therefore tends to overpredict shoreline advance under falling water levels, overlooking the offshore loss of finer sediment fractions. To address this gap, the study introduces a new index, the Compatibility Index (CI), and integrates it into the Bruun rule, comparing six CI methods across six sandy and two sandy–gravel monitoring stations. While the Bruun rule was originally designed for sandy beaches, its applicability was extended here to mixed sand–gravel profiles. A practical decision framework—combining acceptable CI ranges from three prioritized methods and local bed slope—identifies an optimal CI (CI<sub>O</sub>) for each station. Shoreline change from 2013 to 2022 was tracked using cross-shore profiles and high-resolution satellite imagery. Incorporating the CI<sub>O</sub> into the Bruun rule reduced root mean square error from 61.3 m to 21.4 m, mean absolute error from 49.0 m to 16.6 m, and mean bias error from 49.0 m to 14.6 m, improving prediction accuracy by 73.2%. The resulting model delivers robust, site-specific shoreline forecasts and provides a practical tool for coastal managers planning setback zones or adaptation strategies in enclosed-basin environments, while offering a transferable framework for similar settings worldwide.</div></div>","PeriodicalId":18229,"journal":{"name":"Marine Geology","volume":"493 ","pages":"Article 107701"},"PeriodicalIF":2.2,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145928349","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}
Pub Date : 2026-03-01Epub Date: 2026-02-03DOI: 10.1016/j.margeo.2026.107720
Said Alhaddad , Ching-Sen Wu , Lynyrd de Wit
Understanding the behavior of turbidity currents is crucial for the effective and sustainable management of natural and artificial hydraulic systems. This study employs a high-resolution numerical model based on the Large Eddy Simulation (LES) approach to investigate the effect of bed slope on the dynamics and depositional behavior of turbidity currents interacting with a triangular obstacle in a channel. Six bed slopes were studied ranging from 0% to 4.5%. Our analysis focused mostly on the quasi-steady-state flow conditions upstream of the obstacle. The results reveal that steeper slopes enhance sediment transport capacity, leading to reduced sediment deposition rates along the bed and thus a decline in the obstacle’s sediment-retention efficiency. The increased transport capacity primarily results from higher flow velocities rather than increased sediment concentrations. Detailed analysis of velocity distributions upstream of the obstacle, under quasi-steady state, showed that the velocity profiles are distorted differently among bed slopes as a result of the interplay between flow inertia and the adverse pressure gradient induced by the obstacle. Recirculation zones are observed for the milder bed slopes (0–1.5%), whereas these zones disappear for steeper slopes (3–4.5%), indicating the dominance of inertial effects.
{"title":"Effect of bed slope on turbidity currents interacting with an obstacle: Insights from Large Eddy Simulations","authors":"Said Alhaddad , Ching-Sen Wu , Lynyrd de Wit","doi":"10.1016/j.margeo.2026.107720","DOIUrl":"10.1016/j.margeo.2026.107720","url":null,"abstract":"<div><div>Understanding the behavior of turbidity currents is crucial for the effective and sustainable management of natural and artificial hydraulic systems. This study employs a high-resolution numerical model based on the Large Eddy Simulation (LES) approach to investigate the effect of bed slope on the dynamics and depositional behavior of turbidity currents interacting with a triangular obstacle in a channel. Six bed slopes were studied ranging from 0% to 4.5%. Our analysis focused mostly on the quasi-steady-state flow conditions upstream of the obstacle. The results reveal that steeper slopes enhance sediment transport capacity, leading to reduced sediment deposition rates along the bed and thus a decline in the obstacle’s sediment-retention efficiency. The increased transport capacity primarily results from higher flow velocities rather than increased sediment concentrations. Detailed analysis of velocity distributions upstream of the obstacle, under quasi-steady state, showed that the velocity profiles are distorted differently among bed slopes as a result of the interplay between flow inertia and the adverse pressure gradient induced by the obstacle. Recirculation zones are observed for the milder bed slopes (0–1.5%), whereas these zones disappear for steeper slopes (3–4.5%), indicating the dominance of inertial effects.</div></div>","PeriodicalId":18229,"journal":{"name":"Marine Geology","volume":"493 ","pages":"Article 107720"},"PeriodicalIF":2.2,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146170107","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}
Pub Date : 2026-03-01Epub Date: 2026-01-06DOI: 10.1016/j.margeo.2026.107705
Antonio Contreras-de-Villar , Enzo Pranzini , Giorgio Anfuso , Juan J. Muñoz-Perez
Pranzini et al. (2018) designed a method, for borrowed sediment selection in beach nourishment projects, that solved the problems inherent to James' abacus (1975). However, it suffered in turn from the lack of an overfill ratio. A new and more accurate methodology is presented here to calculate the mentioned ratio. To demonstrate the implications of the new proposed method, the overfill ratios calculated are compared with those obtained using the method of James (RA) for nine beaches and nourished sands with different granulometries. The comparison showed that the method of James (1975) predicted a much larger fraction of the borrow sediment to be unstable, thus requiring higher nourishment volumes to achieve a certain beach width and implying increased economic costs.
{"title":"A new and more accurate overfill ratio for beach nourishments and its comparison with James' RA","authors":"Antonio Contreras-de-Villar , Enzo Pranzini , Giorgio Anfuso , Juan J. Muñoz-Perez","doi":"10.1016/j.margeo.2026.107705","DOIUrl":"10.1016/j.margeo.2026.107705","url":null,"abstract":"<div><div><span><span>Pranzini et al. (2018)</span></span> designed a method, for borrowed sediment selection in beach nourishment projects, that solved the problems inherent to James' abacus (1975). However, it suffered in turn from the lack of an overfill ratio. A new and more accurate methodology is presented here to calculate the mentioned ratio. To demonstrate the implications of the new proposed method, the overfill ratios calculated are compared with those obtained using the method of James (R<sub>A</sub>) for nine beaches and nourished sands with different granulometries. The comparison showed that the method of <span><span>James (1975)</span></span> predicted a much larger fraction of the borrow sediment to be unstable, thus requiring higher nourishment volumes to achieve a certain beach width and implying increased economic costs<em>.</em></div></div>","PeriodicalId":18229,"journal":{"name":"Marine Geology","volume":"493 ","pages":"Article 107705"},"PeriodicalIF":2.2,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145979525","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}
Pub Date : 2026-03-01Epub Date: 2026-01-17DOI: 10.1016/j.margeo.2026.107715
Camila Stempels Bautista , Lucía Maisano , Mauricio M. Perillo , Gerardo M.E. Perillo , Diana G. Cuadrado
This study examines bed shear stress generated by combined flows () in a supratidal flat of the Bahía Blanca Estuary during a spring tide coinciding with a positive storm surge driven by an extratropical storm and evaluates the associated sedimentological and biological responses. Bed shear stress was quantified using high-frequency acoustic Doppler velocimeter (ADV) measurements and Reynolds stress estimates. They were analyzed together with cm-scale bedform observations and chlorophyll-a (Chl-a) and phaeopigment concentrations as proxies for photosynthetic microbial activity. Analyses of synoptic maps revealed an extratropical storm advancing SW–NE generating a positive storm surge of up to ∼1 m. During the event, frequently exceeded the critical bed shear stress of sterile sediments (), occurring persistently during ebb tide. During slack tide, sediment transport was observed to occur primarily under the influence of wind-induced waves. Despite the stabilizing effect of the biofilm, which increases , observed changes in surficial micro-geomorphology, together with estimates, indicate that combined flow forcing was sufficient to induce sediment transport during supratidal inundation. These physical disturbances were accompanied by an approximately 40% reduction in Chl-a concentrations during the storm period and a significant increase in phaeopigments. Therefore, the biofilm covering the supratidal flat sediments did not prevent erosion under the hydrodynamic forces generated during an extratropical storm event coupled with a spring tide. This event-based case study highlights the value of integrating hydrodynamic, sedimentological, and biological indicators in a supratidal setting, providing in situ evidence of the coupled response of supratidal flats to extreme hydrodynamic forcing.
{"title":"Combined flow-induced bed shear stress and sediment-biologic dynamics in a supratidal flat of the Bahía Blanca Estuary during a positive storm surge","authors":"Camila Stempels Bautista , Lucía Maisano , Mauricio M. Perillo , Gerardo M.E. Perillo , Diana G. Cuadrado","doi":"10.1016/j.margeo.2026.107715","DOIUrl":"10.1016/j.margeo.2026.107715","url":null,"abstract":"<div><div>This study examines bed shear stress generated by combined flows (<span><math><msub><mi>τ</mi><mn>0</mn></msub></math></span>) in a supratidal flat of the Bahía Blanca Estuary during a spring tide coinciding with a positive storm surge driven by an extratropical storm and evaluates the associated sedimentological and biological responses. Bed shear stress <span><math><msub><mi>τ</mi><mn>0</mn></msub></math></span> was quantified using high-frequency acoustic Doppler velocimeter (ADV) measurements and Reynolds stress estimates. They were analyzed together with cm-scale bedform observations and chlorophyll-<em>a</em> (Chl-<em>a</em>) and phaeopigment concentrations as proxies for photosynthetic microbial activity. Analyses of synoptic maps revealed an extratropical storm advancing SW–NE generating a positive storm surge of up to ∼1 m. During the event, <span><math><msub><mi>τ</mi><mn>0</mn></msub></math></span> frequently exceeded the critical bed shear stress of sterile sediments (<span><math><msub><mi>τ</mi><mrow><mn>0</mn><mi>c</mi></mrow></msub></math></span>), occurring persistently during ebb tide. During slack tide, sediment transport was observed to occur primarily under the influence of wind-induced waves. Despite the stabilizing effect of the biofilm, which increases <span><math><msub><mi>τ</mi><mrow><mn>0</mn><mi>c</mi></mrow></msub></math></span>, observed changes in surficial micro-geomorphology, together with <span><math><msub><mi>τ</mi><mn>0</mn></msub></math></span> estimates, indicate that combined flow forcing was sufficient to induce sediment transport during supratidal inundation. These physical disturbances were accompanied by an approximately 40% reduction in Chl-<em>a</em> concentrations during the storm period and a significant increase in phaeopigments. Therefore, the biofilm covering the supratidal flat sediments did not prevent erosion under the hydrodynamic forces generated during an extratropical storm event coupled with a spring tide. This event-based case study highlights the value of integrating hydrodynamic, sedimentological, and biological indicators in a supratidal setting, providing <em>in situ</em> evidence of the coupled response of supratidal flats to extreme hydrodynamic forcing.</div></div>","PeriodicalId":18229,"journal":{"name":"Marine Geology","volume":"493 ","pages":"Article 107715"},"PeriodicalIF":2.2,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146023701","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}
Pub Date : 2026-02-01Epub Date: 2025-11-19DOI: 10.1016/j.margeo.2025.107679
Matteo Meli , Enrica Vecchi , Claudia Romagnoli
This study aims to reconstruct and analyze shoreline evolution along the highly urbanized Emilia-Romagna coast (Italy) over the period 1984–2023 using satellite-derived shorelines. Landsat and Sentinel-2 imagery were processed with the CoastSat toolbox, and shoreline positions were corrected for tide and wave setup before deriving yearly averages from 2,200 transects. While the spatial resolution of yearly-averaged SDS is lower than that of conventional techniques, this approach enables, for the first time in this region, the reconstruction of shoreline dynamics as a continuous time series spanning interannual to multi-decadal scales. Results highlight substantial spatial and temporal variability across the shoreline, driven by the interplay of natural processes and anthropogenic interventions such as coastal defenses, repeated nourishments, and sediment extraction. Despite ongoing sea-level rise and subsidence, most of the coast exhibits stability or net advancement, largely maintained through human interventions. The resulting dataset provides one of the most temporally extensive records of shoreline variability for the Emilia-Romagna coast and represents a valid basis for future monitoring and coastal management.
{"title":"Shoreline evolution in a low-lying coastal region under anthropogenic influence","authors":"Matteo Meli , Enrica Vecchi , Claudia Romagnoli","doi":"10.1016/j.margeo.2025.107679","DOIUrl":"10.1016/j.margeo.2025.107679","url":null,"abstract":"<div><div>This study aims to reconstruct and analyze shoreline evolution along the highly urbanized Emilia-Romagna coast (Italy) over the period 1984–2023 using satellite-derived shorelines. Landsat and Sentinel-2 imagery were processed with the CoastSat toolbox, and shoreline positions were corrected for tide and wave setup before deriving yearly averages from 2,200 transects. While the spatial resolution of yearly-averaged SDS is lower than that of conventional techniques, this approach enables, for the first time in this region, the reconstruction of shoreline dynamics as a continuous time series spanning interannual to multi-decadal scales. Results highlight substantial spatial and temporal variability across the shoreline, driven by the interplay of natural processes and anthropogenic interventions such as coastal defenses, repeated nourishments, and sediment extraction. Despite ongoing sea-level rise and subsidence, most of the coast exhibits stability or net advancement, largely maintained through human interventions. The resulting dataset provides one of the most temporally extensive records of shoreline variability for the Emilia-Romagna coast and represents a valid basis for future monitoring and coastal management.</div></div>","PeriodicalId":18229,"journal":{"name":"Marine Geology","volume":"492 ","pages":"Article 107679"},"PeriodicalIF":2.2,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145623006","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}
Pub Date : 2026-02-01Epub Date: 2025-12-20DOI: 10.1016/j.margeo.2025.107698
Qi Chen , Yang Zhang , Fangting He , Shihao Liu , Ya Ping Wang , Jianjun Jia
Climate change is increasing the frequency and severity of coastal hazards, with rising sea levels and intensifying typhoons accelerating coastal erosion worldwide. Although headland-bay beaches are widely regarded as topographically protected, they are not immune to substantial erosion during intense typhoons. However, their morphodynamic responses to extreme events—particularly sequential typhoon impacts—remain poorly quantified and mechanistically understood, largely due to the lack of high-resolution monitoring. Here we examine Dasha Beach in Zhejiang Province, China, using high-resolution UAV-derived topography to quantify morphological changes associated with two sequential typhoons, Hinnamnor and Muifa, in September 2022. Hinnamnor generated 9827 m3 of net erosion concentrated in the central beach, and Muifa caused an additional 6370 m3 of erosion, completely removing the remaining beach berm. Post-typhoon recovery deposited 7352 m3 of sediment, predominately reconstructing the northern beach berm, and restoring volumes to pre-Muifa but not pre-Hinnamnor levels. Hydrodynamic analyses reveal pronounced cross-bay gradients in wave energy, with stronger forcing in the northern sector producing enhanced erosion during the typhoons and greater accretion during recovery. During typhoons, waves primarily drove cross-shore sediment transport. In the recovery phase dominated by obliquely incident waves, however, waves facilitated both cross-shore and longshore sediment transport. Swash processes (uprush and backwash) dominated sediment transport, while water-level variations controlled its spatial extent. Specifically, Muifa-induced high water levels combined with energetic waves led to severe berm erosion. The stable berm sediments, derived from well-sorted backshore and dune areas, exhibited minimal grain-size change under typhoon impact. The coarser sediments indicate that the depositional material during the recovery phase originated from the submarine seabed. Although Dasha Beach currently exhibits substantial short-term resilience, increasingly frequent and intense typhoons will pose escalating challenges. Therefore, the assessment of the need for human intervention on the beach and the design of appropriate beach nourishment schemes are among the key focuses for future research. Overall, these findings refine the process-based understanding of storm-driven morphodynamics, and provide a basis for safeguarding headland-bay beach stability.
{"title":"Morphological response and recovery of a headland-bay beach under sequential typhoon impacts","authors":"Qi Chen , Yang Zhang , Fangting He , Shihao Liu , Ya Ping Wang , Jianjun Jia","doi":"10.1016/j.margeo.2025.107698","DOIUrl":"10.1016/j.margeo.2025.107698","url":null,"abstract":"<div><div>Climate change is increasing the frequency and severity of coastal hazards, with rising sea levels and intensifying typhoons accelerating coastal erosion worldwide. Although headland-bay beaches are widely regarded as topographically protected, they are not immune to substantial erosion during intense typhoons. However, their morphodynamic responses to extreme events—particularly sequential typhoon impacts—remain poorly quantified and mechanistically understood, largely due to the lack of high-resolution monitoring. Here we examine Dasha Beach in Zhejiang Province, China, using high-resolution UAV-derived topography to quantify morphological changes associated with two sequential typhoons, Hinnamnor and Muifa, in September 2022. Hinnamnor generated 9827 m<sup>3</sup> of net erosion concentrated in the central beach, and Muifa caused an additional 6370 m<sup>3</sup> of erosion, completely removing the remaining beach berm. Post-typhoon recovery deposited 7352 m<sup>3</sup> of sediment, predominately reconstructing the northern beach berm, and restoring volumes to pre-Muifa but not pre-Hinnamnor levels. Hydrodynamic analyses reveal pronounced cross-bay gradients in wave energy, with stronger forcing in the northern sector producing enhanced erosion during the typhoons and greater accretion during recovery. During typhoons, waves primarily drove cross-shore sediment transport. In the recovery phase dominated by obliquely incident waves, however, waves facilitated both cross-shore and longshore sediment transport. Swash processes (uprush and backwash) dominated sediment transport, while water-level variations controlled its spatial extent. Specifically, Muifa-induced high water levels combined with energetic waves led to severe berm erosion. The stable berm sediments, derived from well-sorted backshore and dune areas, exhibited minimal grain-size change under typhoon impact. The coarser sediments indicate that the depositional material during the recovery phase originated from the submarine seabed. Although Dasha Beach currently exhibits substantial short-term resilience, increasingly frequent and intense typhoons will pose escalating challenges. Therefore, the assessment of the need for human intervention on the beach and the design of appropriate beach nourishment schemes are among the key focuses for future research. Overall, these findings refine the process-based understanding of storm-driven morphodynamics, and provide a basis for safeguarding headland-bay beach stability.</div></div>","PeriodicalId":18229,"journal":{"name":"Marine Geology","volume":"492 ","pages":"Article 107698"},"PeriodicalIF":2.2,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145839915","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}
Pub Date : 2026-02-01Epub Date: 2025-12-20DOI: 10.1016/j.margeo.2025.107699
Lingfeng Luo , Xuguang Feng , Jianjun Zou , Xisheng Fang , Xinru Xue , Ruxi Dou , Baohua Han , Qingchao Wang , Aimei Zhu , Zhi Dong , Gang Yang , Xuefa Shi
Deciphering sediment source-to-sink processes along the continental margin remains a frontier in marine sedimentology and paleoenvironmental research. The thick sedimentary sequences in the East China Sea and the Okinawa Trough provide an ideal setting for deciphering the riverine sediment discharge from East Asian rivers into the ocean and the evolution of the Kuroshio Current. While various proxies have been used to investigate sedimentary processes and paleoenvironmental evolution in the Okinawa Trough, debates persist regarding the variation processes, spatial patterns, and controlling mechanisms of sediment fluxes during the late Quaternary. Here, we present high-resolution bulk minerals from core CSH1 in the northern Okinawa Trough to investigate variations in terrigenous sediment composition, provenance, and fluxes over the last 88 ka BP. Dominant minerals in core CSH1 include quartz, plagioclase, mica, and calcite. Notably, calcite content and the calcite/quartz ratio exhibit lower values in glacials and higher values in interglacials, predominantly reflecting biogenic input. Enhanced Kuroshio Current facilitated warm and nutrient-rich waters to the northern Okinawa Trough and stimulate high calcareous productivity during interglacials. Quartz, plagioclase, and mica are typical detrital minerals, primarily derived from the East Asian continent and the Japan island arc. Sediment provenance indicates that the Changjiang and the Huanghe mixed inputs dominated during Marine Isotope Stage (MIS) 5.1, the Huanghe inputs dominated during MIS 4 to MIS 2, while Japan island arc volcaniclastic contributions increase significantly after 8 ka BP. Sea-level exerts a first-order control on terrestrial sediment supply. Other factors including East Asian Summer Monsoon, Kuroshio Current variability, and paleo-eustasy positioning have secondary influence on sediment pattern of the Okinawa Trough.
在海洋沉积学和古环境研究中，对大陆边缘沉积物源-汇过程的解读一直是一个前沿问题。东海和冲绳海槽的厚层序为解析东亚河流向海洋的泥沙排放和黑潮的演化提供了理想的环境。在冲绳海槽沉积过程和古环境演化的研究中，对晚第四纪沉积通量的变化过程、空间格局和控制机制仍存在争议。在这里，我们利用冲绳海槽北部CSH1岩心的高分辨率大块矿物来研究过去88 ka BP的陆源沉积物组成、物源和通量的变化。CSH1岩心的主要矿物有石英、斜长石、云母和方解石。方解石含量和方解石/石英比值在冰期较低，间冰期较高，主要反映了生物输入。间冰期黑潮的增强促进了冲绳海槽北部温暖而富营养的海水，刺激了高钙质生产力。石英、斜长石和云母是典型的碎屑矿物，主要产自东亚大陆和日本岛弧。沉积物物源特征表明，海相同位素阶段（MIS） 5.1以长江和黄河混合输入为主，MIS 4 ~ MIS 2以黄河输入为主，8 ka BP后日本岛弧火山碎屑贡献显著增加。海平面对陆地沉积物供应起一级控制作用。东亚夏季风、黑潮变率和古海游定位等因素对冲绳海槽沉积格局有次要影响。
{"title":"Environmental changes in the Okinawa Trough over the last 88 ka BP: Evidence from high-resolution bulk mineralogy","authors":"Lingfeng Luo , Xuguang Feng , Jianjun Zou , Xisheng Fang , Xinru Xue , Ruxi Dou , Baohua Han , Qingchao Wang , Aimei Zhu , Zhi Dong , Gang Yang , Xuefa Shi","doi":"10.1016/j.margeo.2025.107699","DOIUrl":"10.1016/j.margeo.2025.107699","url":null,"abstract":"<div><div>Deciphering sediment source-to-sink processes along the continental margin remains a frontier in marine sedimentology and paleoenvironmental research. The thick sedimentary sequences in the East China Sea and the Okinawa Trough provide an ideal setting for deciphering the riverine sediment discharge from East Asian rivers into the ocean and the evolution of the Kuroshio Current. While various proxies have been used to investigate sedimentary processes and paleoenvironmental evolution in the Okinawa Trough, debates persist regarding the variation processes, spatial patterns, and controlling mechanisms of sediment fluxes during the late Quaternary. Here, we present high-resolution bulk minerals from core CSH1 in the northern Okinawa Trough to investigate variations in terrigenous sediment composition, provenance, and fluxes over the last 88 ka BP. Dominant minerals in core CSH1 include quartz, plagioclase, mica, and calcite. Notably, calcite content and the calcite/quartz ratio exhibit lower values in glacials and higher values in interglacials, predominantly reflecting biogenic input. Enhanced Kuroshio Current facilitated warm and nutrient-rich waters to the northern Okinawa Trough and stimulate high calcareous productivity during interglacials. Quartz, plagioclase, and mica are typical detrital minerals, primarily derived from the East Asian continent and the Japan island arc. Sediment provenance indicates that the Changjiang and the Huanghe mixed inputs dominated during Marine Isotope Stage (MIS) 5.1, the Huanghe inputs dominated during MIS 4 to MIS 2, while Japan island arc volcaniclastic contributions increase significantly after 8 ka BP. Sea-level exerts a first-order control on terrestrial sediment supply. Other factors including East Asian Summer Monsoon, Kuroshio Current variability, and paleo-eustasy positioning have secondary influence on sediment pattern of the Okinawa Trough.</div></div>","PeriodicalId":18229,"journal":{"name":"Marine Geology","volume":"492 ","pages":"Article 107699"},"PeriodicalIF":2.2,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145839914","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}
Pub Date : 2026-02-01Epub Date: 2025-10-28DOI: 10.1016/j.margeo.2025.107676
Z.A. Roseby , T. Sengupta , S.L. Ward , D.F. Vosper , M. Blaauw , C.M. Roberts , J.D. Scourse
Continental shelf sediments – particularly soft, muddy habitats - serve as significant reservoirs of organic carbon over glacial-interglacial timescales and are subject to disturbance, notably from mobile bottom fishing gear. The quantity and quality of accumulated organic carbon varies across shelf environments, with muds storing more organic carbon than other substrate types. For effective marine management, it has been recommended that the reactivity, or ‘quality’, of organic matter should be considered when assessing the vulnerability of sedimentary carbon to disturbance. If management interventions are to be made to protect vulnerable organic carbon reservoirs on the seafloor, then it is also important to consider the burial efficiency of carbon. In areas of rapid sediment accumulation, carbon will be moved from surface to geological reservoirs more quickly, thus facilitating carbon sequestration. In this study, we assess the quantity, quality, and accumulation rate of organic carbon in the muddy depocenter of the Fladen Ground, northern North Sea - an area of low active sediment accumulation, with both historic and ongoing bottom trawling. All sediment cores analysed in this study display upwards coarsening of surface sediments, consistent with sediment disturbance and winnowing. Southern Fladen Ground sediments are especially well sorted, depleted in total organic carbon, and enriched in calcium carbonate - patterns that align with intensified trawling. Our results show very low modern organic carbon accumulation rates (∼0.7 g C m−2 yr−1), low organic matter reactivity (18.5 % labile), and that modern trawl events can potentially disturb sediments and carbon accumulated over the last ∼2300 years. These results indicate that sediment and organic carbon accumulation rates are an important consideration when assessing the vulnerability of sedimentary carbon.
大陆架沉积物——尤其是软质、泥泞的栖息地——在冰期-间冰期时间尺度上是有机碳的重要储存库，并容易受到干扰，尤其是来自移动式底部渔具的干扰。累积有机碳的数量和质量因陆架环境而异，淤泥比其他类型的基质储存更多的有机碳。为了有效地管理海洋，有人建议在评估沉积碳对干扰的脆弱性时应考虑有机物的反应性或“质量”。如果要采取管理干预措施来保护海底脆弱的有机碳储层，那么考虑碳的埋藏效率也很重要。在沉积物积聚迅速的地区，碳将更快地从地表转移到地质储层，从而促进碳的固存。在这项研究中，我们评估了北海北部弗拉登地泥质沉积中心有机碳的数量、质量和积累速率，这是一个低活跃沉积物堆积的地区，历史上和现在都有海底拖网捕捞。本研究分析的所有沉积物岩心均显示地表沉积物向上粗化，与泥沙扰动和筛分相一致。弗拉登南部的地面沉积物分选得特别好，总有机碳含量不足，碳酸钙含量丰富——这种模式与密集的拖网捕捞相一致。我们的研究结果表明，现代有机碳积累率非常低（~ 0.7 g C m−2 yr−1），有机质反应性很低（18.5%不稳定），现代拖网事件可能会干扰沉积物和过去~ 2300年积累的碳。这些结果表明，沉积物和有机碳积累速率是评估沉积碳脆弱性的重要考虑因素。
{"title":"Vulnerability of blue carbon stocks to disturbance in sediments with low burial efficiency","authors":"Z.A. Roseby , T. Sengupta , S.L. Ward , D.F. Vosper , M. Blaauw , C.M. Roberts , J.D. Scourse","doi":"10.1016/j.margeo.2025.107676","DOIUrl":"10.1016/j.margeo.2025.107676","url":null,"abstract":"<div><div>Continental shelf sediments – particularly soft, muddy habitats - serve as significant reservoirs of organic carbon over glacial-interglacial timescales and are subject to disturbance, notably from mobile bottom fishing gear. The quantity and quality of accumulated organic carbon varies across shelf environments, with muds storing more organic carbon than other substrate types. For effective marine management, it has been recommended that the reactivity, or ‘quality’, of organic matter should be considered when assessing the vulnerability of sedimentary carbon to disturbance. If management interventions are to be made to protect vulnerable organic carbon reservoirs on the seafloor, then it is also important to consider the burial efficiency of carbon. In areas of rapid sediment accumulation, carbon will be moved from surface to geological reservoirs more quickly, thus facilitating carbon sequestration. In this study, we assess the quantity, quality, and accumulation rate of organic carbon in the muddy depocenter of the Fladen Ground, northern North Sea - an area of low active sediment accumulation, with both historic and ongoing bottom trawling. All sediment cores analysed in this study display upwards coarsening of surface sediments, consistent with sediment disturbance and winnowing. Southern Fladen Ground sediments are especially well sorted, depleted in total organic carbon, and enriched in calcium carbonate - patterns that align with intensified trawling. Our results show very low modern organic carbon accumulation rates (∼0.7 g C m<sup>−2</sup> yr<sup>−1</sup>), low organic matter reactivity (18.5 % labile), and that modern trawl events can potentially disturb sediments and carbon accumulated over the last ∼2300 years. These results indicate that sediment and organic carbon accumulation rates are an important consideration when assessing the vulnerability of sedimentary carbon.</div></div>","PeriodicalId":18229,"journal":{"name":"Marine Geology","volume":"492 ","pages":"Article 107676"},"PeriodicalIF":2.2,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145692428","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}
This study investigates methane seepage dynamics over the past several centuries in the southwestern Barents Sea through an integrated analysis of foraminiferal taphonomy, stable carbon isotopes, and the lipid biomarkers glycerol dialkyl glycerol tetraethers (GDGT) based molecular biomarkers. We examined the preservation state of nine calcareous benthic foraminiferal species from sediment core HH1141, grouping test alterations into five taphonomic categories. These preservation patterns correlate with geochemical indicators of methane emissions, such as depleted δ13C values of carbonate tests and organic matter and elevated Methane Index (MI), allowing the identification of three stratigraphic units reflecting distinct seepage regimes. Along with this gradient, electron microscopy and microprobe analyses reveal widespread diagenetic overgrowths and mineral replacements linked to anaerobic oxidation of methane. Furthermore, species-specific responses highlight that Elphidium clavatum, Stainforthia feylingi, Stainforthia loeblichi and Cassidulina reniforme are more susceptible to alteration, while Melonis barleeanus shows remarkable resistance. The observed temporal variability in methane seepage is interpreted as the result of multifactorial environmental drivers, including changes in subsurface dynamics and bottom-water conditions. This multidisciplinary approach demonstrates the utility of foraminiferal taphonomy as a sensitive proxy for methane-rich environments and cold seep evolution, especially in polar regions undergoing rapid climatic and oceanographic change.
{"title":"Taphonomic signature of benthic foraminifera linked to methane release in the Barents Sea","authors":"Gabriella M. Boretto , Mathia Sabino , Fiorenza Torricella , Gianmarco Ingrosso , Alessio Nogarotto , Giuliana Panieri , Jens Hefter , Gesine Mollenhauer , Leonardo Langone , Silvia Giuliani , Tommaso Tesi , Lucilla Capotondi","doi":"10.1016/j.margeo.2025.107693","DOIUrl":"10.1016/j.margeo.2025.107693","url":null,"abstract":"<div><div>This study investigates methane seepage dynamics over the past several centuries in the southwestern Barents Sea through an integrated analysis of foraminiferal taphonomy, stable carbon isotopes, and the lipid biomarkers glycerol dialkyl glycerol tetraethers (GDGT) based molecular biomarkers. We examined the preservation state of nine calcareous benthic foraminiferal species from sediment core HH1141, grouping test alterations into five taphonomic categories. These preservation patterns correlate with geochemical indicators of methane emissions, such as depleted δ<sup>13</sup>C values of carbonate tests and organic matter and elevated Methane Index (MI), allowing the identification of three stratigraphic units reflecting distinct seepage regimes. Along with this gradient, electron microscopy and microprobe analyses reveal widespread diagenetic overgrowths and mineral replacements linked to anaerobic oxidation of methane. Furthermore, species-specific responses highlight that <em>Elphidium clavatum</em>, <em>Stainforthia feylingi</em>, <em>Stainforthia loeblichi</em> and <em>Cassidulina reniforme</em> are more susceptible to alteration, while <em>Melonis barleeanus</em> shows remarkable resistance. The observed temporal variability in methane seepage is interpreted as the result of multifactorial environmental drivers, including changes in subsurface dynamics and bottom-water conditions. This multidisciplinary approach demonstrates the utility of foraminiferal taphonomy as a sensitive proxy for methane-rich environments and cold seep evolution, especially in polar regions undergoing rapid climatic and oceanographic change.</div></div>","PeriodicalId":18229,"journal":{"name":"Marine Geology","volume":"492 ","pages":"Article 107693"},"PeriodicalIF":2.2,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145748361","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}
Pub Date : 2026-02-01Epub Date: 2025-12-08DOI: 10.1016/j.margeo.2025.107694
Ping Zhang , Linxi Fu , Xiangyuan Li , Jianliang Lin , Huayang Cai , Zhijun Dai , Qingshu Yang
The shoal-channel system, a fundamental geomorphic feature in estuaries globally, plays a crucial role in ensuring navigational safety and sustaining estuarine-deltaic ecosystem services. However, in the Anthropocene, this system has undergone significant transformations, challenging its stability and functional integrity. To investigate these changes, we applied a Digital Elevation Model (DEM) and Morphological Shannon Entropy (MSE) to quantify the stepwise evolution of the shoal-channel system in the Shiziyang (SZY) Tidal Channel, a tide-dominated reach of the Pearl River Estuary (PRE). Our findings reveal that anthropogenic disturbances triggered a systematic eastward channel migration, progressive shoal expansion, and peak erosion of 2.37 × 106 m3/yr during Period III (1989–2000), exceeding concurrent deposition by 50 %. These changes culminated in a systemic reconfiguration from a V-shaped to a W-shaped channel profile. Sequential dredging emerged as the principal driver, accounting for a 17 m incision and contributing up to 68.45 % of the total scouring in Period III. Additional factors, including port construction (which reduced channel width by 20.39 %), diminished sediment flux (causing a 27.65 % decrease in depositional bank extent), and intensified hydrodynamics (reflected by a tidal range increase of 4.56 mm/yr), acted synergistically to amplify the regime shift. By elucidating the key drivers and consequences of this geomorphic evolution, our study provides critical insights for the sustainable management of heavily engineered coastal systems in the Anthropocene.
{"title":"Anthropogenic disturbances drive stepwise geomorphic changes of shoal-channel systems in a tide-dominated estuary","authors":"Ping Zhang , Linxi Fu , Xiangyuan Li , Jianliang Lin , Huayang Cai , Zhijun Dai , Qingshu Yang","doi":"10.1016/j.margeo.2025.107694","DOIUrl":"10.1016/j.margeo.2025.107694","url":null,"abstract":"<div><div>The shoal-channel system, a fundamental geomorphic feature in estuaries globally, plays a crucial role in ensuring navigational safety and sustaining estuarine-deltaic ecosystem services. However, in the Anthropocene, this system has undergone significant transformations, challenging its stability and functional integrity. To investigate these changes, we applied a Digital Elevation Model (DEM) and Morphological Shannon Entropy (MSE) to quantify the stepwise evolution of the shoal-channel system in the Shiziyang (SZY) Tidal Channel, a tide-dominated reach of the Pearl River Estuary (PRE). Our findings reveal that anthropogenic disturbances triggered a systematic eastward channel migration, progressive shoal expansion, and peak erosion of 2.37 × 10<sup>6</sup> m<sup>3</sup>/yr during Period III (1989–2000), exceeding concurrent deposition by 50 %. These changes culminated in a systemic reconfiguration from a V-shaped to a W-shaped channel profile. Sequential dredging emerged as the principal driver, accounting for a 17 m incision and contributing up to 68.45 % of the total scouring in Period III. Additional factors, including port construction (which reduced channel width by 20.39 %), diminished sediment flux (causing a 27.65 % decrease in depositional bank extent), and intensified hydrodynamics (reflected by a tidal range increase of 4.56 mm/yr), acted synergistically to amplify the regime shift. By elucidating the key drivers and consequences of this geomorphic evolution, our study provides critical insights for the sustainable management of heavily engineered coastal systems in the Anthropocene.</div></div>","PeriodicalId":18229,"journal":{"name":"Marine Geology","volume":"492 ","pages":"Article 107694"},"PeriodicalIF":2.2,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145748362","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}
扫码关注我们
求助内容：
应助结果提醒方式：
京公网安备 11010802042870号