Continental Shelf Research最新文献

{"title":"Anomalously warm conditions decrease microphytoplankton abundance in Alfonso Basin, Southwest Gulf of California","authors":"Juan David Acevedo-Acosta ,&nbsp;Rafael Cervantes-Duarte ,&nbsp;Eduardo González-Rodríguez ,&nbsp;Jaime Gómez-Gutiérrez","doi":"10.1016/j.csr.2025.105582","DOIUrl":"10.1016/j.csr.2025.105582","url":null,"abstract":"<div><div>Global warming is significantly impacting coastal ecosystems, modifying the composition and abundance of microphytoplankton species assemblages. This study investigated the effects of prolonged anomalously warm conditions, particularly during El Niño events, on environmental conditions and net primary productivity (NPP) in Alfonso Basin, Southwest Gulf of California. We combined an <em>in situ</em> monthly time series of biogeochemical variables collected from 2022 to 2023 with 2003–2023 monthly satellite-derived data to identify the well-known seasonal pattern with a higher dinoflagellates/diatoms proportion in the summer and autumn and a lower dinoflagellate/diatom proportion in winter and spring. However, it remains unclear how this ratio has shifted under prolonged interannual anomalously warm conditions. Satellite 2003–2023 sea surface temperatures (SST) increased in an inverse relationship with mixed layer depth (MLD) and NPP, particularly from 2014 to 2023, when predominated SST positive anomalies. These changes were associated with decreased northwesterly winds, enhanced water column stratification, and the early influx of tropical seawater mass, all of which were driven by the transition from La Niña to El Niño event that occurred between June and December 2023. This interannual “tropicalization” phenomenon overall decreased microphytoplankton abundance and a shift in community composition increasing dinoflagellate/diatom ratio. We concluded that the interannual and decadal climate variability strongly modulate the dinoflagellate/diatom ratio dynamics. Anomalous warming events, such as those associated with El Niño and marine heat waves drive multi-year hydrological changes in the subtropical Alfonso Basin, resulting in an elevated dinoflagellate/diatom ratio under conditions of anomalous warm temperatures, increased stratification, and prevailing oligotrophic epipelagic conditions.</div></div>","PeriodicalId":50618,"journal":{"name":"Continental Shelf Research","volume":"296 ","pages":"Article 105582"},"PeriodicalIF":2.2,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145326451","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":"Responses of zooplankton (copepods) in the Indian mud bank-upwelling region","authors":"S. Parthasarathi ,&nbsp;R. Jyothibabu ,&nbsp;V. Vidhya ,&nbsp;L. Jagadeesan ,&nbsp;N. Arunpandi ,&nbsp;Unnimaya","doi":"10.1016/j.csr.2025.105576","DOIUrl":"10.1016/j.csr.2025.105576","url":null,"abstract":"<div><div>In 2014 and 2016, the ecology and composition of zooplankton in the Alappuzha mud bank-upwelling area along the southwest (Kerala) coast of India were studied using biweekly sampling from the Pre-Monsoon (PRM) in April to the late Southwest Monsoon (SWM) in September. The zooplankton community was composed of 17 taxa, with copepods accounting for over 70 % of the total abundance. The biomass and abundance increased during both the SWMs of 2014 and 2016, primarily due to an enhancement in phytoplankton caused by nutrient enrichment associated with coastal upwelling. Nonetheless, the 2016 SWM had more suspended sediments and a longer and more severe oxygen deficiency than the 2014 SWM, resulting in lower zooplankton biomass and abundance. Polychaete larvae and gelatinous zooplankton (siphonophores and appendicularians) were also more abundant during the 2016 SWM because of their adaptations to utilise the abundant food while oxygen levels are low. During the PRM, copepods largely consisted of omnivores that effectively used resources in the microbial food web, such as <em>Centropages orsini</em>, <em>C. furcatus</em>, <em>Acartia danae</em>, and <em>A. erythraea</em>. In contrast, the SWM was dominated by copepods such as <em>Temora turbinata</em>, <em>Pseudodiaptomus serricaudatus</em>, and <em>Oithona similis</em>. Due to its ability to survive in low-oxygen settings, <em>O. similis</em> was significantly more prevalent throughout the SWM in both years. <em>Temora turbinata</em>, an indicator species of upwelling, showed higher dominance in the 2016 SWM when oxygen deficiency was more intense and prolonged. Overall, the zooplankton community exhibited the following characteristics: (a) a temporal shift in composition and abundance, (b) dominance of copepods with a preference for the microbial food web during the PRM and hypoxia-adapted ones during the SWM, and (c) a decrease in overall abundance during the 2016 SWM, indicating the negative effects of oxygen deficiency and increased turbidity. Thus, this study establishes a baseline for comparing how zooplankton (copepods) react to different oxygen and turbidity levels in a coastal upwelling mud bank system during alternate SWMs.</div></div>","PeriodicalId":50618,"journal":{"name":"Continental Shelf Research","volume":"296 ","pages":"Article 105576"},"PeriodicalIF":2.2,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145326453","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":"Global marine plastic pollution: Sources, distribution, implications on human health and mitigation strategies","authors":"Abhay B. Fulke ,&nbsp;Shreya Bhanushali ,&nbsp;Harshal S. Jadhav","doi":"10.1016/j.csr.2025.105578","DOIUrl":"10.1016/j.csr.2025.105578","url":null,"abstract":"<div><div>Plastic pollution has emerged as a pressing environmental crisis, with global production surging from 2 million tonnes per year in the 1950s to a staggering 460 million tonnes in 2019. A substantial portion of this plastic waste, over 260,000 tonnes, finds its way into the world's oceans, profoundly impacting marine basins worldwide. Research indicates that an estimated 10 million metric tons of plastic are annually released into aquatic bodies. If current trends continue, an alarming 33 billion tonnes of plastic are projected to accumulate in marine ecosystems by 2050. The pervasive issue of marine litter is dominated by plastic debris, constituting approximately 80 % of all marine waste. Their widespread distribution has raised serious environmental and public health concerns. This comprehensive review identifies the diverse sources of marine plastic whose accumulation results in Global Marine Plastic Pollution (GMPP) and the global distribution of microplastics in the surface waters and sediments across continents and oceans. Moreover, this phenomenon leads to the ingestion of microplastics by various organisms within the marine ecosystem. The alarming nature of this situation calls for immediate action, which has been addressed through the implementation of international policy instruments at the global, regional, and national levels to combat marine plastic pollution. Furthermore, this review discusses the pivotal factors that promote the ingestion of microplastics and assesses their potential implications on marine organisms and human health.</div></div>","PeriodicalId":50618,"journal":{"name":"Continental Shelf Research","volume":"296 ","pages":"Article 105578"},"PeriodicalIF":2.2,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145418560","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":"Warming temperatures and prevalence of marine heatwaves in a temperate fjord","authors":"Claire T. Shellem ,&nbsp;Karin R. Bryan ,&nbsp;Conrad A. Pilditch ,&nbsp;Chris D. Cornelisen ,&nbsp;Joanne I. Ellis","doi":"10.1016/j.csr.2025.105603","DOIUrl":"10.1016/j.csr.2025.105603","url":null,"abstract":"<div><div>Climate change is causing shifts to thermal regimes in coastal marine environments often expressed as alarming marine heat waves; however, such changes are not well understood or observed in fjord environments. Ongoing exposure to intensifying marine heatwaves is becoming increasingly likely and could cause significant and even catastrophic outcomes on the unusual and sensitive ecosystems that characterize fjords. Here we identify spatial and temporal changes in temperature and salinity in the surface waters (0.5–19 m) of a temperate fjord, Doubtful Sound, New Zealand, utilising high resolution data. Data were collected between 2005 and 2023 and recorded at 15-min intervals at three sites, an outer-, mid- and inner-fjord site. IIncreasing temperature anomalies, including two marine heatwave events, were superimposed on seasonal and interannual temperature and salinity patterns. We detect both increasing temperatures through time, from the surface to 19 m and a notable freshening of the near surface low salinity layer. Annual mean temperatures increased at a rate of 0.39–0.67 °C per decade, with the deeper waters (11–19 m) warming faster than shallow waters (&lt;2 m). This is one of the first studies to document the temporal oceanic progression of a heatwave into a fjord, taking several hours for the most intense temperatures to travel from the outermost site to the innermost site, about 30 km. The documented heatwaves in this temperate fjord caused increases of 2–3 °C above mean summer temperatures. Marine heatwaves are emerging as a pervasive threat to marine communities; hence the ecological implications of these findings are considered.</div></div>","PeriodicalId":50618,"journal":{"name":"Continental Shelf Research","volume":"296 ","pages":"Article 105603"},"PeriodicalIF":2.2,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145467315","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":"Detection and temporal variation of the thermal front system in the Midriff Archipelago Region of the Gulf of California","authors":"Amelia Sánchez-Pérez ,&nbsp;Leonardo Tenorio-Fernández ,&nbsp;Emmanuel Romero ,&nbsp;Jorge Montes-Aréchiga ,&nbsp;Laura Sánchez-Velasco","doi":"10.1016/j.csr.2025.105581","DOIUrl":"10.1016/j.csr.2025.105581","url":null,"abstract":"<div><div>Based on 20 years of remote-sensing sea surface temperature (SST) data (2004–2023), the temporal persistence of thermal fronts in the Midriff Archipelago Region (MAR), was analyzed. Using the Front Probability Index and wavelet analysis, six main areas of thermal front formation were identified, along with their oscillation periods. The potential relationship between wind and the formation of thermal fronts was also examined using squared wavelet coherence analysis. The thermal front system exhibited significant seasonal variations in terms of formation, location, and intensity. Most intense fronts were formed in specific areas near both coasts, particularly during spring and summer. Most of the year, fronts in five of the six front-forming areas studied were oriented parallel to the axis of the Gulf of California, while in the remaining area they were predominantly transverse to the Gulf of California axis, mainly during winter. The primary periods of variation for thermal fronts were identified as annual and semiannual. This seasonal pattern ensures the constant presence of fronts in the MAR, highlighting the complexity and dynamics of the system. The formation of fronts is attributed to the interaction of various favorable conditions. The results revealed a high coherence between winds and SST gradients. Southerly winds, which prevail during spring and summer, enhanced the formation and distribution of thermal fronts in the western region while reducing them in the east, whereas northerly winds, dominant in fall and winter, had the opposite effect, reducing fronts in the west and intensifying them in the east. Consequently, this study provides a robust foundation for understanding the temporal and spatial variability of thermal front formation in the MAR, serving as a basis for future research on their potential and their impacts on local marine ecosystems.</div></div>","PeriodicalId":50618,"journal":{"name":"Continental Shelf Research","volume":"296 ","pages":"Article 105581"},"PeriodicalIF":2.2,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145271310","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":"How tides significantly alter the flushing of two large neighboring inverse estuaries","authors":"J. Kämpf","doi":"10.1016/j.csr.2025.105605","DOIUrl":"10.1016/j.csr.2025.105605","url":null,"abstract":"<div><div>A three-dimensional hydrodynamic model is applied to study the flushing of two large neighboring inverse estuaries, Spencer Gulf and Gulf St. Vincent, South Australia, with and without tides. A density-driven overturning circulation, peaking in austral late winter and spring, controls the flushing of both gulfs. Tidal effects significantly affect the flushing of both estuaries with seawater from the ambient continental shelf. Tidally enhanced friction slows the mean flow and significantly reduces the flushing of the Upper Spencer Gulf by ∼9 months. Here, the tidal effect indirectly creates a more hypersaline, dynamically sheltered environment that ecologically supports the world's only mass aggregation of the Giant Australian Cuttlefish (<em>Sepia apama</em>). On the other hand, tidal mixing prevents the accumulation of dense water in a seafloor depression in the lower Gulf St. Vincent which increases the flushing of this region by ∼6 months. Findings of this study reveal the significance and opposite roles that tides play in the unique marine environment of South Australian gulfs.</div></div>","PeriodicalId":50618,"journal":{"name":"Continental Shelf Research","volume":"296 ","pages":"Article 105605"},"PeriodicalIF":2.2,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145520171","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":"Coriolis force effects on the density driven estuarine circulation: Inception of a coastal current","authors":"Tobias Kukulka ,&nbsp;Robert J. Chant","doi":"10.1016/j.csr.2025.105601","DOIUrl":"10.1016/j.csr.2025.105601","url":null,"abstract":"&lt;div&gt;&lt;div&gt;This study investigates theoretically the impact of the Coriolis force on the gravitationally driven estuarine circulation based on the tidally averaged coupled nonlinear momentum and salinity budget equations. Without Coriolis force, it was previously shown that the governing non-dimensional equations for the estuarine circulation depend on two non-dimensional numbers which control the effects of lateral advection and mixing. With Coriolis force, the estuarine circulation is controlled by one additional parameter, a non-dimensional Coriolis parameter, &lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;mi&gt;ϕ&lt;/mi&gt;&lt;msup&gt;&lt;mrow&gt;&lt;mi&gt;δ&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mo&gt;−&lt;/mo&gt;&lt;mn&gt;1&lt;/mn&gt;&lt;/mrow&gt;&lt;/msup&gt;&lt;mo&gt;=&lt;/mo&gt;&lt;mi&gt;f&lt;/mi&gt;&lt;msub&gt;&lt;mrow&gt;&lt;mi&gt;h&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mn&gt;0&lt;/mn&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;msubsup&gt;&lt;mrow&gt;&lt;mi&gt;u&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mi&gt;S&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mo&gt;−&lt;/mo&gt;&lt;mn&gt;1&lt;/mn&gt;&lt;/mrow&gt;&lt;/msubsup&gt;&lt;msup&gt;&lt;mrow&gt;&lt;mi&gt;δ&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mo&gt;−&lt;/mo&gt;&lt;mn&gt;1&lt;/mn&gt;&lt;/mrow&gt;&lt;/msup&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt;, where &lt;span&gt;&lt;math&gt;&lt;mi&gt;f&lt;/mi&gt;&lt;/math&gt;&lt;/span&gt;, &lt;span&gt;&lt;math&gt;&lt;msub&gt;&lt;mrow&gt;&lt;mi&gt;h&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mn&gt;0&lt;/mn&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;/math&gt;&lt;/span&gt;, &lt;span&gt;&lt;math&gt;&lt;msub&gt;&lt;mrow&gt;&lt;mi&gt;u&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mi&gt;S&lt;/mi&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;/math&gt;&lt;/span&gt;, and &lt;span&gt;&lt;math&gt;&lt;mi&gt;δ&lt;/mi&gt;&lt;/math&gt;&lt;/span&gt; symbolize, respectively, the Coriolis parameter, maximum depth, classic estuarine circulation velocity scale, and depth to width aspect ratio. For sufficiently strong vertical mixing, the scaling with Coriolis force predicts qualitatively the dominant budget terms, straightforwardly extending previous scaling results. For this extended scaling, the lateral velocity scale is obtained assuming a balance between vertical friction and pressure gradient forces. For sufficiently rapid rotation and weak vertical mixing, however, the along-channel velocity approaches a geostrophic thermal wind balance violating the straightforward extended scaling. For rapidly rotating estuaries, the equations are alternatively rescaled assuming a geostrophic balance for the along-channel velocity. This rapid rotation scaling reveals the Ekman number Ek&lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;mo&gt;=&lt;/mo&gt;&lt;msub&gt;&lt;mrow&gt;&lt;mi&gt;K&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mi&gt;Z&lt;/mi&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;mo&gt;/&lt;/mo&gt;&lt;mrow&gt;&lt;mo&gt;(&lt;/mo&gt;&lt;mi&gt;f&lt;/mi&gt;&lt;msubsup&gt;&lt;mrow&gt;&lt;mi&gt;h&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mn&gt;0&lt;/mn&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mn&gt;2&lt;/mn&gt;&lt;/mrow&gt;&lt;/msubsup&gt;&lt;mo&gt;)&lt;/mo&gt;&lt;/mrow&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt; as a key non-dimensional number consistent with earlier work (&lt;span&gt;&lt;math&gt;&lt;msub&gt;&lt;mrow&gt;&lt;mi&gt;K&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mi&gt;Z&lt;/mi&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;/math&gt;&lt;/span&gt; is a vertical mixing coefficient). The rapid rotation scaling applies for sufficiently small Ek and predicts a geostrophic balance for the cross-channel direction and, with greater &lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;mi&gt;ϕ&lt;/mi&gt;&lt;msup&gt;&lt;mrow&gt;&lt;mi&gt;δ&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mo&gt;−&lt;/mo&gt;&lt;mn&gt;1&lt;/mn&gt;&lt;/mrow&gt;&lt;/msup&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt;, a mixed geostrophic-Ekman balance in the along-channel direction so that the along-channel velocity approaches a coastal current structure. Furthermore, for rapidly rotating estuaries, the dynamics is nonlinear due to nonlinear coupling of momentum with salinity. The","PeriodicalId":50618,"journal":{"name":"Continental Shelf Research","volume":"296 ","pages":"Article 105601"},"PeriodicalIF":2.2,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145520753","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":"Thermal fronts variability in the Pacific off Mexico and their impact on chlorophyll","authors":"Erick D. Ruvalcaba-Aroche ,&nbsp;Emilio Beier ,&nbsp;Laura Sánchez-Velasco","doi":"10.1016/j.csr.2025.105600","DOIUrl":"10.1016/j.csr.2025.105600","url":null,"abstract":"<div><div>The tropical branch of the California Current (TBCC) converges with tropical waters in the Pacific off Mexico, generating thermal fronts whose hydrographic structure and ecological implications remain poorly understood. Using satellite-derived sea surface temperature (SST) data (2003–2021) and <em>in situ</em> measurements from four oceanographic cruises, this study examines the spatiotemporal variability of thermal fronts and their relationship with chlorophyll-<em>a</em> (CHL) as a proxy for productivity. Fronts were persistent along the peninsular coast, driven by coastal upwelling, with seasonal shifts in distribution: spring showed the highest frontal prevalence south of 24 °N, while summer activity shifted northward (26–28 °N). Autumn and winter exhibited minimal frontal activity. Seasonal variability explained 20–50 % of frontal occurrence in coastal zones and the oceanic zone south of 23 °N but was negligible offshore. The cold phase of ENSO (La Niña) correlated with enhanced frontal activity and elevated CHL, particularly south of 24 °N. A significant positive correlation between frontal probability and mesoscale CHL anomalies highlighted two key oceanic regions where fronts likely boost productivity: near Punta Eugenia (25–29 °N) and Cabo San Lucas (20–24 °N), especially in spring and summer. <em>In situ</em> data revealed that spring fronts featured steep thermocline slopes and coincided with CHL gradients, whereas autumn fronts lacked vertical structure and ecological influence. These findings underscore the role of thermal fronts in modulating productivity in the TBCC, particularly during spring and summer, while emphasizing the limited ecological impact of density-compensated fronts in autumn.</div></div>","PeriodicalId":50618,"journal":{"name":"Continental Shelf Research","volume":"296 ","pages":"Article 105600"},"PeriodicalIF":2.2,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145418564","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":"Ebb-tidal delta and sand bar construction offshore Shell Island, Florida","authors":"John A. Goff","doi":"10.1016/j.csr.2025.105597","DOIUrl":"10.1016/j.csr.2025.105597","url":null,"abstract":"<div><div>The shoreface is a highly dynamic sedimentary environment, and also a challenging one to obtain stratigraphic data due to shallow depths and surf zone condition. A pole-mounted chirp subbottom profiler survey was conducted in May 2021 along the shoreface of Shell Island, Florida. These data are investigated with the aim characterizing sediment dynamics of an underwater unexploded ordinance test bed location. The Shell Island shoreface consists of three principal sedimentary units in the shallow subsurface. The substrate consists of the MAFLA marine sand sheet, which is organized into oblique-to-shore sand ridges, and which merges with the barrier island sands of Shell Island. Along the lower shoreface/inner shelf, this substrate is overlain by an ebb-tidal delta unit associated with sands exiting through St. Andrews Pass, the 1930's-era ship channel constructed by the US-Amy Corps of Engineers for access to Saint Andrews Bay, and transported to the SE. The ebb-tidal delta is prograding alongshore to the SE, as evidenced by the internal dipping reflectors, and consistent with the measured sediment transport direction. I calculate that the ebb-tidal delta has grown by ∼0.92x10⁶ m³/yr since the opening of the Pass. Along the upper shoreface, the substrate is overlain by the nearshore sandbar, organized into crescentic morphology of alternating highs and lows with a spacing of ∼750 m alongshore. The sand bars are underlain by a strong seaward-dipping reflector, inferred to be the basal surface for mobile sands. The sand bars overlie the ebb-tidal delta unit, indicating a prograding shoreline.</div></div>","PeriodicalId":50618,"journal":{"name":"Continental Shelf Research","volume":"296 ","pages":"Article 105597"},"PeriodicalIF":2.2,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145364468","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":"Characterisation of the eddy-driven variability inshore of the Agulhas Current using sea surface temperature observations","authors":"N. Burgher ,&nbsp;L. Braby ,&nbsp;S. Herbette ,&nbsp;JC Hermes ,&nbsp;MJ Roberts","doi":"10.1016/j.csr.2025.105598","DOIUrl":"10.1016/j.csr.2025.105598","url":null,"abstract":"<div><div>Off the east coast of South Africa, coastal waters inshore of the Agulhas Current are largely affected by oceanic mesoscale turbulence, primarily in the form of meanders such as Natal Pulses and Durban Eddies. This study utilises forty years of modern, high-resolution satellite sea surface temperature (SST) data, offering both improved spatial detail and a longer time series than previous products, to characterise these eddies using an automated meander detection algorithm. Notably, automated detection has never before been applied to Durban Eddies, and Natal Pulses have not been analysed using such a high-resolution, long-term SST dataset. The algorithm successfully estimated the daily position of the inshore edge and core of the Agulhas Current and the “first occurrence” of Agulhas waters for the period of the study —the latter defined as the initial emergence of Agulhas Current waters in a filament or plume associated with Natal Pulses. The analysis reveals that the inshore edge of the Agulhas Current is not subject to seasonal variation but is significantly influenced by the presence of Natal Pulses and Durban Eddies. The first occurrence of Agulhas Current waters was only detected during the passage of Natal Pulses. Results indicate increased variability in regions south of 29.8°S, with Natal Pulses showing an increase in size and surface lifespan in the southern region. Conversely, Durban Eddies exhibit a decrease in size and surface lifespan as they propagate southward. Furthermore, seasonal SST anomalies are generally small, with cold events more frequent; Natal Pulses cause higher variability, while Durban Eddies maintain relative stability.</div></div>","PeriodicalId":50618,"journal":{"name":"Continental Shelf Research","volume":"296 ","pages":"Article 105598"},"PeriodicalIF":2.2,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145418563","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}