Marine Geology最新文献

{"title":"Turbidity current flow structure and its modulation by contour currents: Insights from 3D flume experiments","authors":"P.H. Adema ,&nbsp;J.T. Eggenhuisen ,&nbsp;J. Bleeker ,&nbsp;R. Silva Jacinto ,&nbsp;E. Miramontes","doi":"10.1016/j.margeo.2024.107469","DOIUrl":"10.1016/j.margeo.2024.107469","url":null,"abstract":"<div><div>Turbidity currents are the main agent transferring sediment, carbon, nutrients and pollutants (e.g. micro-plastics) from the continents to the deep sea. They flow through submarine canyons, connecting the continents to the oceans. Along their trajectory, these flows may interact with a suite of oceanographic processes, such as geostrophic contour currents, forming a mixed system, entraining material from the turbidity current into the large-scale ocean system<em>.</em> Turbidity current–contour current interaction is scarcely evaluated and their combined three-dimensional flow structure is poorly constrained. We conducted experiments showing the 3D flow structure of turbidity currents and how this structure is modified by contour currents for different contour current velocities, channel depths, and morphologies. Secondary flow cells are observed in the experimental turbidity currents inside the straight channel. This secondary flow is bi-cellular for the purely gravity-driven experiments. Contour currents collapse this bi-cellular structure into a single cell constrained to the downstream channel margin. Additionally, the contour currents modulate the overspilling behavior of the flow by reducing overspill on the upstream overbank and making overspill thicker and faster on the downstream overbank. Our results illustrate the importance of secondary circulation in turbidity currents and their structural modulation by contour currents.</div></div>","PeriodicalId":18229,"journal":{"name":"Marine Geology","volume":"480 ","pages":"Article 107469"},"PeriodicalIF":2.6,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143097650","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Investigating the origin and dynamics of Carolina Bays","authors":"Mark Lundine ,&nbsp;Arthur Trembanis","doi":"10.1016/j.margeo.2024.107449","DOIUrl":"10.1016/j.margeo.2024.107449","url":null,"abstract":"<div><div>This study compiles a myriad of previously published and novel results from field-based and remote sensing investigations of Carolina Bays (shallow, circular to elliptic, sandy-rimmed, coastal plain depressions), aiming at identifying possible origin mechanisms as well as future research avenues. These investigations include neural network-based detection and morphometric analysis of over 20,000 Carolina Bays across the Atlantic Coastal Plain from digital elevation models; sedimentological investigations at Bays in Delaware, Virginia, North Carolina, and South Carolina; satellite-based surface water mapping of Bay lakes in North Carolina; a compilation of published geochronological data extracted from Carolina Bay sediments; collection of hydrodynamic data from a Carolina Bay pond; and geologic and geomorphic comparisons between Bays and similar depressions found in North America. This synthesis shows that Carolina Bays and similar depressions are widespread on unglaciated provinces composed of unconsolidated sediments, where wind was likely the main forcing mechanism which initially scoured out the depressions. Wave processes likely produced the Bays' characteristic round to ovate planform shape, with water-level fluctuations leaving behind sand rims as paleoshorelines. Holocene warming, increased humidity, and an increase in vegetation cover has induced more benign geomorphic conditions within Carolina Bays, during which finer sediment and organic matter has filled in these depressions. Modern observations of Carolina Bays and related features show little modern geomorphic activity. Geochronological data shows that Bays originated and underwent geomorphic modification from Marine Isotope Stage 5 to Marine Isotope Stage 1, coeval with the growth and decay of the Laurentide Ice Sheet, as well as with the development of nearby sand dunes. The available geochronological evidence is not compatible with an impact origin for the Bays, particularly one related to the Younger Dryas impact hypothesis or one related to Australasian tektites dating to 788 ka. The results of this synthesis should encourage future research into field-based, modeling, and synthetic investigations of Bays and similar depressions.</div></div>","PeriodicalId":18229,"journal":{"name":"Marine Geology","volume":"480 ","pages":"Article 107449"},"PeriodicalIF":2.6,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143150022","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":"Geomorphology of the northern and southern continental margins of the Iberian Peninsula: Quaternary interplay of tectonics and sedimentation","authors":"Gemma Ercilla ,&nbsp;Jesús Galindo-Zaldívar ,&nbsp;Carmen Juan ,&nbsp;Ferran Estrada ,&nbsp;Jorge Iglesias ,&nbsp;Javier Valencia ,&nbsp;Víctor Tendero-Salmerón ,&nbsp;Elia d'Acremont ,&nbsp;María del Carmen Fernández-Puga ,&nbsp;Lourdes González-Castillo ,&nbsp;Asier Madarieta-Txurruka ,&nbsp;Desiree Palomino ,&nbsp;Manuel Teixeira ,&nbsp;Juan Tomás Vázquez","doi":"10.1016/j.margeo.2024.107467","DOIUrl":"10.1016/j.margeo.2024.107467","url":null,"abstract":"<div><div>Through a comparison of the physiography and Quaternary deposits and features of three tectonically deformed Iberian continental margins by the NW–SE convergent Eurasia-Iberian-Africa plates, we attempt to address the influence of the interplay of tectonics and sedimentation on their geomorphology. The areas include the currently active southern Iberian Alboran and Gulf of Vera margins in the SW Mediterranean and the inactive northern Iberian Cantabrian margin in the Atlantic. The margin study comprises two major physiographic compartments, the continental shelf and the distal margin, where the latter also includes the adjacent bathyal water depths. Similarities and differences are highlighted in the tectonic influences and their signatures in the sedimentary geomorphology during the Quaternary. On the continental shelf, the active or inactive onshore uplift appears to have conditioned the seafloor gradients and the preservation of the Quaternary deposits, which subsequently influenced their width. In the distal continental margin, offshore regional structural features (whether active or inactive) govern the complex and oversteepened topography, overall geometry of the sea basin, along-margin intraslope basins and regional tectonic tilting, influencing all the downslope and alongslope sedimentary processes. Thus, Quaternary tectonic processes and/or inherited morphotectonic parameters have influenced the geomorphology of shelf regressive deposits, canyons, gullies, fans, mass movement deposits, and contourites. Two types of tectonic margins based on sedimentary geomorphology are characterised: dismantled (Gulf of Vera and Cantabrian margins) and constructional (Iberian Alboran margin). This study has relevance far beyond the Iberian regional scale because it provides insights into the tectonic signatures of sedimentary geomorphology. The categorised margin types may serve as analogues for contemporary marine sedimentary basins where tectonics plays a prominent role in sediment transport, deposition, erosion, and remobilisation via their influence on both active and inactive topography.</div></div>","PeriodicalId":18229,"journal":{"name":"Marine Geology","volume":"480 ","pages":"Article 107467"},"PeriodicalIF":2.6,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143093137","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Impact of Paleocene–Eocene tectonic and climatic forcing on Arctic sediment transfer variability: SW Barents Sea, Norway","authors":"Amando P.E. Lasabuda ,&nbsp;Domenico Chiarella ,&nbsp;Tor Oftedal Sømme ,&nbsp;Sten-Andreas Grundvåg ,&nbsp;Isak Eikelmann ,&nbsp;Stig-Morten Knutsen ,&nbsp;Anthony George Doré ,&nbsp;Jan Sverre Laberg ,&nbsp;Tom Arne Rydningen ,&nbsp;Alfred Hanssen ,&nbsp;Bent Kjølhamar","doi":"10.1016/j.margeo.2024.107447","DOIUrl":"10.1016/j.margeo.2024.107447","url":null,"abstract":"<div><div>During the Paleocene and Eocene, many Arctic basins experienced multiple, yet synchronous periods of increased sedimentation rates. Several causal factors have been suggested including major volcanic events, tectonic plate reorganization and plate break-up, as well as widespread uplift along with contemporaneous and short-lived hyperthermal events. However, the significance of and relation between tectonic and climatic forcing on Arctic sediment transfer during the early Paleogene are poorly understood. In this case study from the Barents Shelf margin in the Norwegian Arctic, we present previously unpublished cores combined with exploration wells, and new high-resolution 3D seismic data to investigate sedimentary stacking patterns and geomorphological features in the Sørvestsnaget Basin. Our integrated investigations reveal the development of climate-controlled and tectonically-driven submarine fans. The PETM fans display an individual fan as a result of single depositional event compared to the middle Eocene fans that show stacked submarine fans probably deposited during multi-phase events. Our stratigraphic forward modelling analysis indicates that regional-scale tectonically induced uplift significantly increased the amount of sand delivered to the basin as documented by a thickening of the basin fill succession. The climatic component contributes to sand transport variability to the basin, and thus the temporal evolution pattern of sand is much varied. Finally, we discuss our findings with the tectonic and climatic forcing factors in a circum-Arctic perspective.</div></div>","PeriodicalId":18229,"journal":{"name":"Marine Geology","volume":"480 ","pages":"Article 107447"},"PeriodicalIF":2.6,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143097643","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Geomorphological signatures of known hurricanes and validation of theoretical emplacement formulations: Coastal boulder deposits on Cuban low-lying marine terraces","authors":"Pedro Dunán-Avila ,&nbsp;Christine Authemayou ,&nbsp;Marion Jaud ,&nbsp;Kevin Pedoja ,&nbsp;Julius Jara-Muñoz ,&nbsp;Stephane Bertin ,&nbsp;Leandro Peñalver-Hernández ,&nbsp;France Floc'h ,&nbsp;Arelis Nuñez-Labañino ,&nbsp;Patricio Winckler ,&nbsp;Jean Pierre-Toledo ,&nbsp;Pedro Benítez-Frometa ,&nbsp;Hassan Ross-Cabrera ,&nbsp;Pauline Letortu ,&nbsp;Angel Raúl Rodríguez-Valdés ,&nbsp;Noel Coutín-Lobaina ,&nbsp;Denovan Chauveau","doi":"10.1016/j.margeo.2024.107438","DOIUrl":"10.1016/j.margeo.2024.107438","url":null,"abstract":"<div><div>Coastal boulder deposits, observed worldwide, provide geomorphological evidence of extreme wave events such as storms, hurricanes and tsunamis. Theoretical formulations have been developed for determining hydrodynamic conditions responsible for boulder emplacement on the shore, which increasingly make use of boulder geometry and associated site geomorphology. Nevertheless, information on extreme events responsible for the emplacement of coastal boulders is rarely available, meaning there has been limited opportunity to test existing formulations in the light of real hydrodynamic and geomorphic data. In this study, we take advantage of the important record of coastal boulder deposits on Cuba Island to compare the hydrodynamic parameters (minimum flow velocity) deduced from the boulders' morphology and emplacement characteristics, with hydrodynamic conditions (maximum wave height and orbital velocity) that occurred during the tropical cyclones responsible for the boulders' actual emplacement. We selected four sites where three hurricanes have emplaced five boulders on low-lying coral reef terraces over the last 50 years. Using terrestrial Structure-from-Motion photogrammetry, we determined with precision the boulders' shape and volume, which in combination with density, mode of emplacement and distance from the shore, were used to calculate the minimum flow velocity responsible for dislocation of the coral reef terrace and inland transport. To serve as comparisons, available modelled data of wave height and period were used to estimate the maximum orbital velocity that possibly occurred during the weather event using linear wave theory. Our results show that for all boulders studied except one, there is a good agreement between the values of minimum flow and maximal orbital velocities, with minimum flow velocities for boulder emplacement consistently smaller than the maximum wave orbital velocity during the weather event. The difference observed for one boulder is attributed to specific site effects, highlighting in this case the limitation of using distant hydrometeorological data for characterizing wave processes responsible for coastal boulder deposits. Helped by detailed data collected on boulders with large differences in morphology including size, and mode of emplacement, this study confirms the pertinence of using formulations relating boulder morphology and site characteristics to the minimum flow velocity that detached and transported the boulder. It further emphasizes the importance of obtaining adequate boulder and geomorphic setting characterizations to link geomorphological proxies and extreme wave events.</div></div>","PeriodicalId":18229,"journal":{"name":"Marine Geology","volume":"480 ","pages":"Article 107438"},"PeriodicalIF":2.6,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143097646","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Sediment gravity flows drive the buildup of the modern Huanghe (Yellow River) delta front","authors":"Yupeng Pan ,&nbsp;Shihao Liu ,&nbsp;Fei Xing ,&nbsp;Ya Ping Wang ,&nbsp;Yonggui Yu ,&nbsp;Ting Chen ,&nbsp;Qingsong Liu","doi":"10.1016/j.margeo.2024.107468","DOIUrl":"10.1016/j.margeo.2024.107468","url":null,"abstract":"<div><div>The rapid development of the delta front is heavily influenced by sediment gravity flows (SGFs), posing significant challenges to coastal infrastructure. Accurately assessing the long-term impacts of SGFs—triggered by river floods, slope failures, and wave activities—on delta front geomorphology and sedimentation patterns remains a complex task. This complexity is heightened during the formative stages of delta development, where distinguishing between the contributions of different SGF triggers is particularly challenging. To address this, we employed the forward stratigraphic model Sedflux-2D, integrating key input parameters, such as initial bathymetry, river discharge, suspended sediment concentration, and wave height, based on observed values. The model was calibrated against seismic stratigraphy and sediment core grain size data to reconstruct the annual-to-decadal evolution of the modern Huanghe Delta (MHD). By comparing the simulated outputs with present-day bathymetry and grain size distributions, we quantitatively evaluated the impacts of SGFs driven by primary factors such as wave energy, river discharge, and slope stability on MHD front development. Our findings reveal that, during the transition from nearshore to offshore environments, sediment grain size distribution within the delta strata is predominantly controlled by SGFs driven by waves, river fed, and collapses. Hyperpycnal flows, generated by river floods, contribute significantly to deltaic sediment dynamics, accounting for approximately 20 % of total sediment volume and 30–50 % of foreset progradation over sub-decadal to decadal timescales. Collapse-induced SGFs, meanwhile, are responsible for approximately 25 % of foreset sediment volume loss, influencing bottomset development beyond 10 m water depth. These findings highlight the critical role of hyperpycnal flows in shaping the MHD front. This study integrates forward simulation with inverse sediment record analysis, providing a robust framework for quantifying the contributions of SGFs to delta front development. The comprehensive insights gained from this approach are essential for informed decision-making in delta management.</div></div>","PeriodicalId":18229,"journal":{"name":"Marine Geology","volume":"480 ","pages":"Article 107468"},"PeriodicalIF":2.6,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143150024","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":"Sediment flux variation and environmental implications in the East Hainan Coast, South China Sea during the last 20 ka—a luminescence chronological investigation","authors":"Yang Li ,&nbsp;Yan Li ,&nbsp;Mianjin Chen ,&nbsp;Yulong Xue ,&nbsp;Jingran Zhang ,&nbsp;Li Wang ,&nbsp;Changliang Tong ,&nbsp;Liang Yi","doi":"10.1016/j.margeo.2024.107453","DOIUrl":"10.1016/j.margeo.2024.107453","url":null,"abstract":"<div><div>Sediments deposited on the continental shelf are indicative of paleo sea-level and terrestrial-marine interaction. A reliable chronology of the continental shelf sediments is required for paleoenvironmental and paleoceanographical investigations. In this study, the chronology of the terrestrial-to-marine sedimentary sequence in the East Hainan Coast, South China Sea (SCS), was established using luminescence and radiocarbon dating approaches. The luminescence characteristics of quartz post-infrared (pIR)-blue and pIR-pulsed OSL signals, K-feldspar and polymineral IR and post-IR IRSL (pIRIR) signals, were thoroughly studied and compared using six representative samples. The quartz pIR-blue and pIR-pulsed OSL ages are generally consistent with each other. The pIRIR₁₅₀ (subscript shows the stimulation temperature) ages slightly underestimate the associated quartz luminescence ages, likely due to fading under-correction. Chronology of the sediments was established using the post-IR blue OSL ages, indicating the terrestrial-to-marine sedimentation occurred during the last 20 ka. Episodic sedimentation in the East Hainan Coast was revealed by slow sedimentation during the periods of pre- (19.7–11.5 ka) and mid-Holocene (8.7–7.0 ka), while rapid sedimentation occurred during the early Holocene (11.5–8.7 ka). The exposed environment and the Younger Dryas cold event may be attributed to the slow sedimentation during the periods of ca. 19.7–14.3 and 12.9–11.5 ka, whilst the rapidly rising sea-level during 14.3–12.9 ka resulted in rare sedimentation under the coastal to neritic environments. Tremendous fluvial input corresponding to considerable precipitation resulted from intensification of the East Asian Summer Monsoon during the early Holocene (11.5–8.7 ka). Deepening water level, inundation of the Qiongzhou Strait and vegetation densification, may change the process of sediment transportation, source and flux, causing slow sedimentation in the eastern inner shelf to the Hainan Island in the mid-Holocene (8.7–7.0 ka).</div></div>","PeriodicalId":18229,"journal":{"name":"Marine Geology","volume":"480 ","pages":"Article 107453"},"PeriodicalIF":2.6,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143150023","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":"High-precision estimation of a paleo-tsunami inundation area by identifying tsunami traces beyond sandy tsunami deposits: A case study of the 869 CE Jogan tsunami in Fukushima, northeastern Japan","authors":"Kaito Komeiji ,&nbsp;Tetsuya Shinozaki ,&nbsp;Daisuke Sugawara ,&nbsp;Takashi Ishizawa ,&nbsp;Minoru Ikehara ,&nbsp;Shigehiro Fujino","doi":"10.1016/j.margeo.2025.107490","DOIUrl":"10.1016/j.margeo.2025.107490","url":null,"abstract":"<div><div>Previous tsunami deposit studies have considered the distribution of visible sandy tsunami deposits as a tool to establish inundation areas and limits, but use of this area for tsunami magnitude estimation may cause it to be underestimated because the actual inundation limit of a tsunami rarely coincide with the depositional limit of visible sandy tsunami deposits. In this study, we aimed to reconstruct with high accuracy the inundation area of the Jogan tsunami, which occurred off the Pacific coast of the Tohoku region of Japan in 869 CE, by using sedimentological and geochemical methods to identify tsunami traces inland from the depositional limit of the tsunami deposits that are difficult to see by eye. We collected sediment samples at Minamisoma City, Fukushima Prefecture. Based on radiocarbon dating, grain-size analysis of sand, increased amounts of marine-derived elements such as Ca and Sr, and the presence of characteristic biomarkers, visible traces of sandy Jogan tsunami deposits were recognized up to 2280 m from the present coastline. Although no visible sandy tsunami deposits were observed farther inland, at 2790 m from the present coastline, evidence of seawater inundation was inferred from computed tomography image analysis, grain-size distribution of sand, presence of pumice, detection of squalene, and other allochthonous biomarkers. Detection of tsunami traces enables a highly accurate estimation of tsunami inundation areas, leading to a more accurate estimation of the source and scale of earthquakes.</div></div>","PeriodicalId":18229,"journal":{"name":"Marine Geology","volume":"481 ","pages":"Article 107490"},"PeriodicalIF":2.6,"publicationDate":"2025-01-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143177755","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Sediment bypassing around a headland in a high-energy coastal environment","authors":"Charlotte F.K. Uphues ,&nbsp;Graziela Miot da Silva ,&nbsp;Arnold van Rooijen ,&nbsp;Patrick A. Hesp","doi":"10.1016/j.margeo.2025.107491","DOIUrl":"10.1016/j.margeo.2025.107491","url":null,"abstract":"<div><div>Accurately estimating sediment transport rates is essential for predicting shoreline changes and guiding coastal management strategies. While existing longshore transport models primarily assume alongshore uniform sandy shorelines, the reality is usually more complex. Many coastal environments exhibit natural features and engineered structures that challenge these models by altering sediment transport and morphodynamic processes. This study presents observations from an extensive field campaign at the Cape Dombey headland in Robe, South Australia, incorporating a co-located acoustic current meter and sediment profiler to examine sediment bypassing during summer and winter. Offshore and nearshore wave characteristics and water levels were measured, with nearshore wave heights ranging from <span><math><mo>∼</mo></math></span>0.5 m in summer to &gt;2.5 m during winter storms. Statistical analysis revealed wave refraction, diffraction, and breaking over a submerged headland extension as the main drivers for wave transformation around the headland. Three distinct hydrodynamic regimes were identified, characterized by specific current directions and sediment transport rates around the headland. A novel conceptual model for headland bypassing is proposed, describing these regimes and identifying sediment transport patterns over event time scales. Sediment transport rates under swell-dominant (Regime 2) and sea-dominant (Regime 3) conditions were up to 30 and 40 times higher than during calm conditions (Regime 1). Our conceptual model builds upon existing models by providing a detailed description of headland bypassing mechanisms under various hydrodynamic forcing conditions. This study advances understanding of sediment transport around headlands in high-energy environments and provides an adaptable framework for measuring and analyzing headland bypassing in other coastal settings.</div></div>","PeriodicalId":18229,"journal":{"name":"Marine Geology","volume":"481 ","pages":"Article 107491"},"PeriodicalIF":2.6,"publicationDate":"2025-01-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143177756","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Modeling gas, hydrates, and slope stability on the U.S. Atlantic margin during Pleistocene glacial cycles","authors":"Olin R. Carty ,&nbsp;Warren T. Wood ,&nbsp;Benjamin J. Phrampus ,&nbsp;Taylor R. Lee ,&nbsp;Jennifer M. Frederick ,&nbsp;Michael Nole ,&nbsp;David Fukuyama ,&nbsp;Hugh Daigle","doi":"10.1016/j.margeo.2025.107492","DOIUrl":"10.1016/j.margeo.2025.107492","url":null,"abstract":"<div><div>Changes in temperature and sea level can cause dissociation of methane hydrates in shallow marine sediments, leading to seafloor destabilization. Along the U.S. Atlantic margin, there exists a well-documented history of slope failure and numerous recorded occurrences of gas seeps. Several studies have linked slope failure in the region to gas seepage and hydrate dissociation driven by glacial-interglacial transitions, but this linkage has not been quantitatively demonstrated. Along the shelf edge, in an area where shallow methane gas seeps have been identified, we modeled methane gas and hydrate formation using ensembles of one-dimensional fluid flow simulations. Methane gas formation was modeled over the last 120,000 years to simulate a glacial-interglacial cycle. We ran this model at 16,044 individual locations in the region between <span><math><msup><mn>29</mn><mo>∘</mo></msup></math></span> N – <span><math><msup><mn>45</mn><mo>∘</mo></msup></math></span> N and <span><math><msup><mn>82</mn><mo>∘</mo></msup></math></span> W – <span><math><msup><mn>66</mn><mo>∘</mo></msup></math></span> W at a resolution of 1 × 1 arcminutes, focusing specifically on water depths between 200 and 1000 m that bracket the seafloor outcrop of the base of the hydrate stability zone. Using historic temperature and pressure records from the last 120,000 years, sediment properties in the area, and factor of safety calculations, we found that hydrate dissociation alone is unlikely to cause slope failure in the region, implying that an additional driving force would be necessary for failure to occur.</div></div>","PeriodicalId":18229,"journal":{"name":"Marine Geology","volume":"481 ","pages":"Article 107492"},"PeriodicalIF":2.6,"publicationDate":"2025-01-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143372414","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}