Pub Date : 2025-10-01Epub Date: 2025-07-17DOI: 10.1016/j.margeo.2025.107619
Haoshen Liang , Aijun Wang , Chui Wei Bong , Shuqin Tao , Boyu Liu , Kar Hoe Loh , Xiang Ye , Yi You Wong , Haiqi Li , Choon Weng Lee
Small- and medium-sized mountainous rivers (SMRs) are critical pathways for delivering terrestrial sediment to coastal systems, particularly in the tropical regions where their dynamics are highly sensitive to anthropogenic influences. This study investigates the sediment transport processes and ultimate deposition patterns in the Selangor River estuary, Malaysia - a representative tropical macrotidal estuary characterized by complex nearshore topography and weak Coriolis effects. By combining field measurements (2023–2024) with sediment analysis, this research reveals three key findings. First, approximately 73.5 % of the annual sediment discharge (19.75 × 104 t) accumulates in estuarine tidal flats, with the northern tidal flats receiving twice the deposition of the southern tidal flats. Second, distinct seasonal transport regimes were evident: (i) during the dry season wave-driven sediment resuspension and tidal forces result in northwestward-southeastward transport, (ii) during the wet season stratified flows lead to significant sediment-freshwater decoupling, where river plumes disperse offshore while terrestrial sediments remain trapped near the estuary. Third, the unique sediment trapping mechanism, different from both large river systems and wave-dominated tropical SMRs, resulting from the interaction of strong tidal currents, seasonal river discharge, and offshore water intrusion form the Strait of Malacca. These findings provide a new conceptual framework for understanding sediment retention in tropical macrotidal estuaries, with implications for coastal management under climate change and intensifying anthropogenic pressures.
{"title":"Mechanisms and seasonal variability of sediment transport in a small tropical mountainous estuary-coastal system: Insights from the Selangor River, Malaysia","authors":"Haoshen Liang , Aijun Wang , Chui Wei Bong , Shuqin Tao , Boyu Liu , Kar Hoe Loh , Xiang Ye , Yi You Wong , Haiqi Li , Choon Weng Lee","doi":"10.1016/j.margeo.2025.107619","DOIUrl":"10.1016/j.margeo.2025.107619","url":null,"abstract":"<div><div>Small- and medium-sized mountainous rivers (SMRs) are critical pathways for delivering terrestrial sediment to coastal systems, particularly in the tropical regions where their dynamics are highly sensitive to anthropogenic influences. This study investigates the sediment transport processes and ultimate deposition patterns in the Selangor River estuary, Malaysia - a representative tropical macrotidal estuary characterized by complex nearshore topography and weak Coriolis effects. By combining field measurements (2023–2024) with sediment analysis, this research reveals three key findings. First, approximately 73.5 % of the annual sediment discharge (19.75 × 10<sup>4</sup> t) accumulates in estuarine tidal flats, with the northern tidal flats receiving twice the deposition of the southern tidal flats. Second, distinct seasonal transport regimes were evident: (i) during the dry season wave-driven sediment resuspension and tidal forces result in northwestward-southeastward transport, (ii) during the wet season stratified flows lead to significant sediment-freshwater decoupling, where river plumes disperse offshore while terrestrial sediments remain trapped near the estuary. Third, the unique sediment trapping mechanism, different from both large river systems and wave-dominated tropical SMRs, resulting from the interaction of strong tidal currents, seasonal river discharge, and offshore water intrusion form the Strait of Malacca. These findings provide a new conceptual framework for understanding sediment retention in tropical macrotidal estuaries, with implications for coastal management under climate change and intensifying anthropogenic pressures.</div></div>","PeriodicalId":18229,"journal":{"name":"Marine Geology","volume":"488 ","pages":"Article 107619"},"PeriodicalIF":2.6,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144678898","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 : 2025-10-01Epub Date: 2025-06-18DOI: 10.1016/j.margeo.2025.107606
Yunwei Wang , Yali Qi , Qian Yu
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.
{"title":"Rapid retreat of marsh-edge cliffs, Jiangsu coast, China","authors":"Yunwei Wang , Yali Qi , 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":"2025-10-01","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}
Pub Date : 2025-10-01Epub Date: 2025-06-02DOI: 10.1016/j.margeo.2025.107592
A. Piña , J. Stock , D. Lizarralde , S. Hart , K. Marsaglia , C. Gallegos-Castillo , C. Berndt , A. González-Fernández , C. Mortera-Gutiérrez , A. Martín-Barajas
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.
{"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 , J. Stock , D. Lizarralde , S. Hart , K. Marsaglia , C. Gallegos-Castillo , C. Berndt , A. González-Fernández , C. Mortera-Gutiérrez , 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":"2025-10-01","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}
Pub Date : 2025-09-01Epub Date: 2025-05-16DOI: 10.1016/j.margeo.2025.107581
Andrew Kennedy , Rónadh Cox , Max Engel , Emma Speyrer , Annie Lau , Nobuhito Mori
Coastal boulder deposits are long-lived signatures of high-energy storm wave and tsunami inundation found on rocky and reefal coastlines worldwide. Although increasing numbers of research reports have been published on coastal boulder deposits, it has been difficult to compare studies from different areas because of a lack of standardised data and of quality-controlled datasets. This paper describes ISROC-DB, a new standardised database compiled from both published and unpublished data. There are two important parts: 1. Uniform standards to enable collation and intercomparison of coastal boulder deposits, with preformatted Excel files to enable convenient data entry; and 2. A freely accessible compiled database of coastal boulder deposit data. Both are published in downloadable permanent archives. Ongoing additions will further increase the database scope.
{"title":"The Inundation Signatures on Rocky Coastlines Global Database for coastal boulder deposits (ISROC-DB)","authors":"Andrew Kennedy , Rónadh Cox , Max Engel , Emma Speyrer , Annie Lau , Nobuhito Mori","doi":"10.1016/j.margeo.2025.107581","DOIUrl":"10.1016/j.margeo.2025.107581","url":null,"abstract":"<div><div>Coastal boulder deposits are long-lived signatures of high-energy storm wave and tsunami inundation found on rocky and reefal coastlines worldwide. Although increasing numbers of research reports have been published on coastal boulder deposits, it has been difficult to compare studies from different areas because of a lack of standardised data and of quality-controlled datasets. This paper describes ISROC-DB, a new standardised database compiled from both published and unpublished data. There are two important parts: 1. Uniform standards to enable collation and intercomparison of coastal boulder deposits, with preformatted Excel files to enable convenient data entry; and 2. A freely accessible compiled database of coastal boulder deposit data. Both are published in downloadable permanent archives. Ongoing additions will further increase the database scope.</div></div>","PeriodicalId":18229,"journal":{"name":"Marine Geology","volume":"487 ","pages":"Article 107581"},"PeriodicalIF":2.6,"publicationDate":"2025-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144072229","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 : 2025-09-01Epub Date: 2025-05-29DOI: 10.1016/j.margeo.2025.107590
Puneet Kumar Mishra , R. Mani Murali , Deepika Dwivedi , S.K. Ariful Hossain , S. Santhosh Kumar , Shincy Francis , Richa Rai
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.
{"title":"Impacts of climate change on the morphodynamics of embayed beaches along the Central West Coast of India","authors":"Puneet Kumar Mishra , R. Mani Murali , Deepika Dwivedi , S.K. Ariful Hossain , S. Santhosh Kumar , Shincy Francis , 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":"2025-09-01","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}
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.
{"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 , Ayumi Maeda , Atsuko Amano , Juichiro Ashi , Asuka Yamaguchi , Yusuke Yokoyama , 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":"2025-09-01","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}
Pub Date : 2025-09-01Epub Date: 2025-05-25DOI: 10.1016/j.margeo.2025.107591
Taian Lu , Thomas S. Bianchi , Naishuang Bi , Xiao Wu , Shuai Cong , Jinya Xu , Xiaoyan Ning , Houjie Wang
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.
{"title":"Particulate organic carbon dynamics off the Yellow River Estuary revealed by in-situ hydrodynamics and carbon isotopes","authors":"Taian Lu , Thomas S. Bianchi , Naishuang Bi , Xiao Wu , Shuai Cong , Jinya Xu , Xiaoyan Ning , 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":"2025-09-01","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}
Pub Date : 2025-09-01Epub Date: 2025-05-08DOI: 10.1016/j.margeo.2025.107577
Dayton Dove , Tom Bradwell , Natasha L.M. Barlow
Reconstructions of sea level change in NW Europe are primarily based on records of relative sea level (RSL) recovered from terrestrial environments, above modern sea level. This deficit in marine-based records results from the highly limited number of sea level indicators observed in modern submarine settings, as well as the often-limited absolute chronology information available. This sampling bias introduces significant uncertainty in former RSL predictions, negatively impacting efforts to accurately model ice-sheet histories and isostatic response. Here we present new seabed mapping data (i.e. high-resolution multibeam bathymetry) from northern Scotland to address this data gap. Encircling the Orkney Islands we identify an exceptional sequence of submerged terraces ranging from -5 to -95 m below modern sea level, carved in bedrock. We interpret these bedrock terraces as relict shore platforms, based on their spatial distribution and a range of geomorphological characteristics. Shore platform development was linked to contemporaneous landward coastline erosion and cliff formation, and each landform pair (i.e. terrace = shore platform and accompanying seacliff / escarpment) likely represents a single sea-level stillstand event of considerable duration (possibly millennia). These wide and well-preserved shore platforms attest to formation during multiple, separate periods of RSL stillstand, and we estimate that 5–7 RSL stillstands are recorded offshore Orkney. We discuss their potential age – spanning more than the last glacial cycle (i.e. Middle - Late Pleistocene) – and explore the wider implications for Quaternary coastal erosion and sea-level change in the region. This study shows how marine geological data and geomorphological analysis can be used to identify palaeo-sea-level indicators within a glacio-isostatically complex region. Despite a current lack of absolute chronological constraint, we believe these observations may provide crucial information towards understanding sea level change within the NW European region.
{"title":"Submerged bedrock shore platforms, Orkney Islands, UK: A new record of significant, though chronologically uncertain sea-level change and coastal erosion","authors":"Dayton Dove , Tom Bradwell , Natasha L.M. Barlow","doi":"10.1016/j.margeo.2025.107577","DOIUrl":"10.1016/j.margeo.2025.107577","url":null,"abstract":"<div><div>Reconstructions of sea level change in NW Europe are primarily based on records of relative sea level (RSL) recovered from terrestrial environments, above modern sea level. This deficit in marine-based records results from the highly limited number of sea level indicators observed in modern submarine settings, as well as the often-limited absolute chronology information available. This sampling bias introduces significant uncertainty in former RSL predictions, negatively impacting efforts to accurately model ice-sheet histories and isostatic response. Here we present new seabed mapping data (i.e. high-resolution multibeam bathymetry) from northern Scotland to address this data gap. Encircling the Orkney Islands we identify an exceptional sequence of submerged terraces ranging from -5 to -95 m below modern sea level, carved in bedrock. We interpret these bedrock terraces as relict shore platforms, based on their spatial distribution and a range of geomorphological characteristics. Shore platform development was linked to contemporaneous landward coastline erosion and cliff formation, and each landform pair (i.e. terrace = shore platform and accompanying seacliff / escarpment) likely represents a single sea-level stillstand event of considerable duration (possibly millennia). These wide and well-preserved shore platforms attest to formation during multiple, separate periods of RSL stillstand, and we estimate that 5–7 RSL stillstands are recorded offshore Orkney. We discuss their potential age – spanning more than the last glacial cycle (i.e. Middle - Late Pleistocene) – and explore the wider implications for Quaternary coastal erosion and sea-level change in the region. This study shows how marine geological data and geomorphological analysis can be used to identify palaeo-sea-level indicators within a glacio-isostatically complex region. Despite a current lack of absolute chronological constraint, we believe these observations may provide crucial information towards understanding sea level change within the NW European region.</div></div>","PeriodicalId":18229,"journal":{"name":"Marine Geology","volume":"487 ","pages":"Article 107577"},"PeriodicalIF":2.6,"publicationDate":"2025-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144070405","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 : 2025-09-01Epub Date: 2025-05-25DOI: 10.1016/j.margeo.2025.107589
Xin Ni , Xiuguo Liu , Shilong Pang , Yifei Dong , Binbin Guo , Yuhang Zhang , Yang Wu , Danyi Su , Andi Xu , Qinmeng Yuan , Xuemin Wu , Lin Yang , Xiaoyu Wu , Zhigang Wang , Xi Xiao , Qianyong Liang
Marine sediments contain substantial methane reservoirs that play a significant role in global carbon cycling and climate systems. However, methane seepage is significantly influenced by ocean dynamics, with poorly understood spatiotemporal patterns. To investigate the spatiotemporal distribution patterns of methane seepage and the regulatory mechanisms of ocean currents, comprehensive coordinates and flux data of methane seepage from multiple marine regions worldwide were compiled. The spatial characteristics of methane seepage were quantified using nearest neighbor analysis and kernel density estimation, whereas the local and global autocorrelation between seepage activities, ocean currents, and sea surface temperatures were evaluated using Moran's index. Two clustering algorithms, spatiotemporal density-based spatial clustering of applications with noise (ST-DBSCAN) and ordering points to identify the clustering structure (OPTICS), were employed to identify the synergistic effects between temperature gradients and ocean current convergence zones through multiscale and hierarchical clustering approaches. Deep ocean currents may regulate methane seepage through multiple pathways: affecting hydrate stability via temperature gradients, altering local pressure fields through water level and flow velocity fluctuations, and influencing microbial geochemical processes through water mass exchange. The results indicate that methane seepage is most active in the circum-Pacific region and continental shelf areas, with approximately 42 % of seepage hotspots occurring in warm–cold current convergence zones. Mesoscale identification at 500 km reveals the influence of hydrodynamic processes such as eddies and fronts, whereas accessibility analysis quantitatively characterizes the hierarchical spatial associations of methane seepage, indicating enhanced seepage activity in warm current regions. These findings demonstrate the multiple control mechanisms of ocean currents on seafloor methane release through coupled temperature, pressure, and geochemical effects. This research provides a scientific foundation and a technical reference for quantitatively assessing the potential contribution of marine methane to global carbon cycling and identifying areas susceptible to elevated seepage.
{"title":"Global marine methane seepage: Spatiotemporal patterns and ocean current control","authors":"Xin Ni , Xiuguo Liu , Shilong Pang , Yifei Dong , Binbin Guo , Yuhang Zhang , Yang Wu , Danyi Su , Andi Xu , Qinmeng Yuan , Xuemin Wu , Lin Yang , Xiaoyu Wu , Zhigang Wang , Xi Xiao , Qianyong Liang","doi":"10.1016/j.margeo.2025.107589","DOIUrl":"10.1016/j.margeo.2025.107589","url":null,"abstract":"<div><div>Marine sediments contain substantial methane reservoirs that play a significant role in global carbon cycling and climate systems. However, methane seepage is significantly influenced by ocean dynamics, with poorly understood spatiotemporal patterns. To investigate the spatiotemporal distribution patterns of methane seepage and the regulatory mechanisms of ocean currents, comprehensive coordinates and flux data of methane seepage from multiple marine regions worldwide were compiled. The spatial characteristics of methane seepage were quantified using nearest neighbor analysis and kernel density estimation, whereas the local and global autocorrelation between seepage activities, ocean currents, and sea surface temperatures were evaluated using Moran's index. Two clustering algorithms, spatiotemporal density-based spatial clustering of applications with noise (ST-DBSCAN) and ordering points to identify the clustering structure (OPTICS), were employed to identify the synergistic effects between temperature gradients and ocean current convergence zones through multiscale and hierarchical clustering approaches. Deep ocean currents may regulate methane seepage through multiple pathways: affecting hydrate stability via temperature gradients, altering local pressure fields through water level and flow velocity fluctuations, and influencing microbial geochemical processes through water mass exchange. The results indicate that methane seepage is most active in the circum-Pacific region and continental shelf areas, with approximately 42 % of seepage hotspots occurring in warm–cold current convergence zones. Mesoscale identification at 500 km reveals the influence of hydrodynamic processes such as eddies and fronts, whereas accessibility analysis quantitatively characterizes the hierarchical spatial associations of methane seepage, indicating enhanced seepage activity in warm current regions. These findings demonstrate the multiple control mechanisms of ocean currents on seafloor methane release through coupled temperature, pressure, and geochemical effects. This research provides a scientific foundation and a technical reference for quantitatively assessing the potential contribution of marine methane to global carbon cycling and identifying areas susceptible to elevated seepage.</div></div>","PeriodicalId":18229,"journal":{"name":"Marine Geology","volume":"487 ","pages":"Article 107589"},"PeriodicalIF":2.6,"publicationDate":"2025-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144154884","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 : 2025-09-01Epub Date: 2025-05-16DOI: 10.1016/j.margeo.2025.107580
Amin Rashidi , Mohammad Mokhtari , Katsuichiro Goda , Mehdi Masoodi , Parvaneh Faridi
Seismic profiles have revealed historical submarine landslides within the western part of the Makran Subduction Zone (MSZ). A specific underwater landslide, identified off the coast of Chabahar, Iran, has been modeled to assess the potential hazard of the resultant tsunami waves in the MSZ. This submerged landslide near Chabahar has a volume of 7 km3. To evaluate the tsunami hazard, three scenarios have been developed: one static and two dynamic. According to the simulations, Chabahar experiences high waves, reaching heights of 5 m around its coast, with corresponding runup amplitudes of up to 10 m. Emphasizing the significance of dynamic considerations in understanding the tsunamigenesis of submarine landslides, the two dynamic scenarios differ primarily in landslide travel distance and, consequently, duration. The numerical modeling outcomes indicate that the dynamic scenario with the longer travel distance yields higher tsunami waves, reaching a maximum height of 15 m in the Oman Sea. Conversely, the other dynamic scenario generates waves with amplitudes similar to those produced in the static scenario. It takes about 15 min for the tsunami to reach Chabahar Station. Major ports in the region, including Chabahar, Jask, Muscat, and Sur, face elevated threats from the potential impact of this landslide-triggered tsunami. Notably, the shoreline of Pakistan exhibits a comparatively lower threat level in contrast to Iran and Oman. Looking ahead, future studies aim to compile a comprehensive database of tsunamigenic scenarios based on all potential landslides identified through seismic sections and bathymetry topology. This will enhance our understanding of the region's tsunami hazard from landslide-tsunamis.
{"title":"A landslide tsunami hazard assessment in the Makran Subduction Zone","authors":"Amin Rashidi , Mohammad Mokhtari , Katsuichiro Goda , Mehdi Masoodi , Parvaneh Faridi","doi":"10.1016/j.margeo.2025.107580","DOIUrl":"10.1016/j.margeo.2025.107580","url":null,"abstract":"<div><div>Seismic profiles have revealed historical submarine landslides within the western part of the Makran Subduction Zone (MSZ). A specific underwater landslide, identified off the coast of Chabahar, Iran, has been modeled to assess the potential hazard of the resultant tsunami waves in the MSZ. This submerged landslide near Chabahar has a volume of 7 km<sup>3</sup>. To evaluate the tsunami hazard, three scenarios have been developed: one static and two dynamic. According to the simulations<strong>,</strong> Chabahar experiences high waves, reaching heights of 5 m around its coast, with corresponding runup amplitudes of up to 10 m. Emphasizing the significance of dynamic considerations in understanding the tsunamigenesis of submarine landslides, the two dynamic scenarios differ primarily in landslide travel distance and, consequently, duration. The numerical modeling outcomes indicate that the dynamic scenario with the longer travel distance yields higher tsunami waves, reaching a maximum height of 15 m in the Oman Sea. Conversely, the other dynamic scenario generates waves with amplitudes similar to those produced in the static scenario. It takes about 15 min for the tsunami to reach Chabahar Station. Major ports in the region, including Chabahar, Jask, Muscat, and Sur, face elevated threats from the potential impact of this landslide-triggered tsunami. Notably, the shoreline of Pakistan exhibits a comparatively lower threat level in contrast to Iran and Oman. Looking ahead, future studies aim to compile a comprehensive database of tsunamigenic scenarios based on all potential landslides identified through seismic sections and bathymetry topology. This will enhance our understanding of the region's tsunami hazard from landslide-tsunamis.</div></div>","PeriodicalId":18229,"journal":{"name":"Marine Geology","volume":"487 ","pages":"Article 107580"},"PeriodicalIF":2.6,"publicationDate":"2025-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144089359","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}
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