Marine Geology最新文献_第3页

Geomorphic control of wave run-up by berm morphology on sandy beaches 沙质海滩护堤形态对波浪上升的地貌控制

IF 2.2 3区地球科学 Q2 GEOSCIENCES, MULTIDISCIPLINARY

Marine Geology

Pub Date : 2026-02-01 Epub Date: 2025-12-10 DOI: 10.1016/j.margeo.2025.107692

Yingtao Zhou , Zheng Li , Yu Zhu , Yuanshu Jiang , Xi Feng , Weibing Feng , Yulong Xue , Jutong Zhang

This study aims to advance the current understanding of the role that the berm plays in modulating wave run-up dynamics for elevation control purposes. Accurate prediction of wave run-up is essential for coastal hazard assessment and management, yet existing empirical models often fail to account for the dynamic influence of berm morphology. This study introduces a new empirical formula for wave run-up that solves the current wave run-up empirical formula can not adequately consider the instantaneous changes in the berm (including width, elevation, and onshore slope). Using field measurements from sandy beaches in Haikou, China, combined with numerical simulations (XBeach) and video-derived run-up data from a Coastal Shore-based Video Imagery Monitoring System (COSVIMS), we analyze run-up behavior on composite-profile beaches featuring a gentle berm and steep dune. Results demonstrate that berm geometry significantly attenuates run-up: a higher and wider berm reduces both vertical elevation and horizontal extent of run-up. The proposed model which including berm height (h_B), berm platform length (L_B), and the onshore slope of the berm ridge (β_Son) outperforms established formulations across multiple international beach datasets, showing higher correlation and lower root-mean-square error (RMSE = 0.046) than old models. By capturing real-time feedback between berm evolution and run-up, this improved formula resolves the issue of asynchrony between hydrodynamics and run-up, thereby providing a robust basis for real-time calculations of wave-topography interactions.

本研究旨在促进目前对护堤在调节波浪上升动力学以达到高程控制目的中的作用的理解。海浪上升的准确预测对海岸灾害评估和管理至关重要，但现有的经验模型往往不能考虑到护堤形态的动态影响。本文提出了一种新的波浪爬高经验公式，解决了目前波浪爬高经验公式不能充分考虑护堤瞬时变化（包括宽度、高程、岸坡）的问题。利用海口市沙滩的野外测量数据，结合数值模拟（XBeach）和海岸岸基视频图像监测系统（COSVIMS）的视频衍生助跑数据，分析了具有平缓护堤和陡峭沙丘的复合剖面海滩的助跑行为。结果表明，护堤的几何形状显著地减弱了爬升：更高和更宽的护堤降低了爬升的垂直高度和水平程度。该模型包含了滩高（hB）、滩台长度（LB）和滩脊岸坡（βSon），在多个国际海滩数据集上优于现有的公式，具有更高的相关性和更低的均方根误差（RMSE = 0.046）。该改进公式通过捕获堤道演变和助跑之间的实时反馈，解决了水动力和助跑之间的不同步问题，从而为波浪-地形相互作用的实时计算提供了坚实的基础。

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引用次数: 0

Control of sediment supply and fault-controlled topography on the evolution of undulating bedforms in the Eastern Shenhu Slope, northern South China Sea 南海北部神狐坡东部坡面起伏地貌演化中的沉积物供给控制与断层地形控制

IF 2.2 3区地球科学 Q2 GEOSCIENCES, MULTIDISCIPLINARY

Marine Geology

Pub Date : 2026-02-01 Epub Date: 2025-12-26 DOI: 10.1016/j.margeo.2025.107702

Kunwen Luo , Ming Su , Shan Liu , Zhi Lin Ng , Zhixuan Lin , Ce Wang , Hui Chen , Haiteng Zhuo

Depositional and erosional bedforms are prevalent in submarine environments worldwide, and have the potential to preserve critical records of continental margin evolution, ocean circulation, climate variability, and paleo-geohazards. However, the origin and evolution of such bedforms remain debated. This study employs high-resolution three-dimensional seismic reflection data to investigate the origin, evolution, and controlling factors of undulating bedforms on the eastern Shenhu slope, northern South China Sea. Morphometric analyses of these bedforms, as well as morphometric-based calculating of turbidity currents velocity, distinguish them as turbidity current-generated bedforms. Initiated since Marine Isotope Stage (MIS) 38 (horizon SB3) until the present, bedforms on the Shenhu slope are divided into two stages: (1) from MIS 38 to MIS 20 (horizons SB3–SB4), where erosional crescentic scours and elongated troughs, are formed under vigorous turbidity currents; (2) from MIS 12 to the present (horizon SB5–seafloor), where depositional bedforms, sediment waves, with near-linear crests, formed under relatively weaker current. Their evolution was governed by the interplay of the progradation of the paleo-Pearl River shelf-edge delta and the development of a horsetail normal fault system in the upper slope, with an increase in sediment supply since 1.6 Ma and a decrease in fault activity between 2.58 Ma until 474 ka (MIS 12). Fault-controlled conduits enhanced current velocity and erosion until MIS 20, which transitioned into unconfined flows and depositional waves as faults were progressively buried. These findings highlight the pivotal roles of sediment supply and seafloor topography in shaping deep-water sedimentary systems, offering insights into the sedimentary dynamics on continental margins.

沉积和侵蚀床型在全球海底环境中普遍存在，并有可能保存大陆边缘演化、海洋环流、气候变化和古地质灾害的重要记录。然而，这种床型的起源和演化仍有争议。利用高分辨率三维地震反射资料，探讨了南海北部神狐坡东部起伏地貌的成因、演化及其控制因素。对这些床型的形态计量学分析，以及基于形态计量学的浊流流速计算，将它们区分为浊流产生的床型。神虎斜坡自38期（SB3层）开始至今，形成了两个阶段：1)38期至20期（SB3 - sb4层），形成了强浊流作用下的侵蚀新月形冲刷槽和细长槽；(2)从MIS 12到现在（sb5 -海床层），在相对较弱的洋流作用下形成了沉积层，沉积波具有近线性波峰。它们的演化受古珠江陆架边缘三角洲的进积和上坡马尾正断层系统发育的相互作用支配，1.6 Ma以来泥沙供应增加，2.58 Ma至474 ka之间断层活动减少（MIS 12）。断层控制的管道增强了流速和侵蚀，直到MIS 20，随着断层逐渐被掩埋，它转变为无约束流和沉积波。这些发现强调了沉积物供应和海底地形在形成深水沉积体系中的关键作用，为大陆边缘的沉积动力学提供了见解。

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引用次数: 0

Early Pleistocene (1.94–1.46 Ma) records for the upper Mediterranean Outflow Water branch reveal low and high latitude climate influences 早更新世（1.94-1.46 Ma）地中海上游流出水分支的记录揭示了低纬度和高纬度气候的影响

IF 2.2 3区地球科学 Q2 GEOSCIENCES, MULTIDISCIPLINARY

Marine Geology

Pub Date : 2026-02-01 Epub Date: 2025-12-13 DOI: 10.1016/j.margeo.2025.107697

Antje H.L. Voelker , Emanuelle Ducassou , Barbara Balestra , Jose Abel Flores , Gary D. Acton , Carl Richter , Chuang Xuan , Johanna Lofi , Ana Alberto , Henning Kuhnert , Carlos A. Alvarez Zarikian

The Mediterranean Outflow Water (MOW), modified by paleoceanographic conditions and tectonic processes, played a significant role in the formation of sediments drifts along the Iberian Margin. Using sediment samples from IODP Hole U1387C, we explore the Early Pleistocene history of the upper MOW core above the central Faro Drift in the Gulf of Cádiz. The time series of benthic foraminifer stable isotope and grain size related data have a rigorous stratigraphic framework consisting of nannofossil biostratigraphy and paleomagnetic and δ¹⁸O stratigraphy. The paleoenvironmental records are supplemented by natural gamma ray downhole logging data. Above the hiatus associated with the youngest dolostone, sandy to muddy contourite sedimentation started at 1.946 Ma, i.e., within Marine Isotope Stage (MIS) 74, at IODP Site U1387, slightly younger than at IODP Site U1389. Formation of contourite layers, reflected in the sortable silt and sand percentage records, strongly reacted to precession forcing, including semi- and quarter-precession cycles. The majority of the contourite beds developed during stadial (colder) climate periods, like previous observations from the Early to Late Pleistocene. Formation of contourite layers within MIS 53, MIS 55 and MIS 65, however, appear to be linked to the prevailing atmospheric conditions over North Africa. Periods of poor ventilation in the upper MOW were linked to insolation maxima and reduced ventilation in the Mediterranean Sea. Here, MIS 51 presents a peculiar case as poor ventilation reached from the surface to the lower North Atlantic Deep Water range, reflecting unique interglacial conditions that merit future exploration.

受古海洋条件和构造作用的影响，地中海流出水在伊比利亚边缘沉积物漂移的形成中起着重要作用。利用odp U1387C孔沉积物样品，研究了Cádiz湾法罗流中心上部MOW上部岩心的早更新世历史。底栖有孔虫稳定同位素时间序列和粒度相关数据具有由纳米化石生物地层学、古地磁地层学和δ18O地层学组成的严格的地层格架。自然伽马测井资料补充了古环境记录。在与最年轻的白云岩相关的断裂带之上，在IODP站点U1387，砂质到泥质轮廓岩沉积开始于1.946 Ma，即在海洋同位素阶段（MIS） 74，略低于IODP站点U1389。可分选的粉砂和砂的百分比记录表明，等高沉积层的形成强烈地反映了岁差强迫，包括半岁差和四分之一岁差旋回。大部分的等长岩层是在正常（较冷）气候时期发育的，就像以前从早更新世到晚更新世的观测结果一样。然而，MIS 53、MIS 55和MIS 65内轮廓层的形成似乎与北非的主要大气条件有关。MOW上部通风不良的时期与地中海的日照最大值和通风减少有关。在这里，MIS 51呈现了一个特殊的情况，即从北大西洋深水区到地表的通风不良，反映了独特的间冰期条件，值得未来的勘探。

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引用次数: 0

The updated distribution of clay minerals in the World Ocean 世界海洋粘土矿物的最新分布

IF 2.2 3区地球科学 Q2 GEOSCIENCES, MULTIDISCIPLINARY

Marine Geology

Pub Date : 2026-02-01 Epub Date: 2025-12-08 DOI: 10.1016/j.margeo.2025.107695

Taylor R. Lee , Taylor Vander , Trilby Hill , Jeffrey Obelcz , Benjamin Phrampus , Jordan Graw

Clay mineral content in marine sediments is central to a wide variety of applications in the marine geosciences, including paleoclimate reconstruction and slope stability analyses. Most studies are not applicable to a global scale, focusing on single locations or regional areas. Additionally, dominant clay mineral data (kaolinite, illite, smectite, chlorite) are not curated for “big data” applications necessary to produce estimates on a global scale. Geospatial machine learning (GML) techniques have successfully produced global predictions of geological seafloor properties, such as sedimentation rate and total organic carbon. Here, we curate observed data of dominant clay mineral concentration for use in a GML algorithm to predict global surficial (< 1 m) seafloor estimates of relative clay mineral abundances. Our global seafloor clay mineral predictions are qualitatively similar to previous global estimates, but have more dynamic range and finer-scale spatial variation. Our results show that GML predictions are the best data-driven estimate (∼2-3× decrease in error) of clay mineral concentration where it has not been previously measured.

Plain language summary

Clay minerals in marine seafloor sediments are important to a variety of marine geology applications including reconstructing ancient climates and assessing slope instability hazards. Most of these studies publish sparse data that is limited to particular regions of the world. The inconsistent formatting of these data makes it difficult to utilize in a “big data” framework (e.g., machine learning applications). We harvest thousands of sparse clay mineral observations from a variety of different public sources including literature and repositories. We standardize these data in a manner compatible with machine learning efforts. We then utilize machine learning algorithms to estimate the global distribution of dominant clay minerals in shallow marine seafloor (< 1 m) sediments. Finally, we compare our predictions with previously published maps. Our predictions are descriptively similar, but statistically more accurate.

海洋沉积物中的粘土矿物含量在海洋地球科学中有着广泛的应用，包括古气候重建和边坡稳定性分析。大多数研究并不适用于全球范围，而是侧重于单个地点或区域。此外，主要的粘土矿物数据（高岭石、伊利石、蒙脱石、绿泥石）并没有为“大数据”应用进行整理，而产生全球范围内的估算是必要的。地理空间机器学习（GML）技术已经成功地产生了海底地质属性的全球预测，如沉积速率和总有机碳。在这里，我们整理了主要粘土矿物浓度的观测数据，用于GML算法来预测全球表面（< 1 m）海底相对粘土矿物丰度的估计。我们的全球海底粘土矿物预测在质量上与以前的全球估计相似，但具有更大的动态范围和更细尺度的空间变化。我们的研究结果表明，GML预测是以前没有测量过的粘土矿物浓度的最佳数据驱动估计（误差降低~ 2-3倍）。海洋海底沉积物中的粘土矿物对各种海洋地质应用非常重要，包括重建古代气候和评估边坡不稳定危险。大多数这些研究发表的稀疏数据仅限于世界上的特定地区。这些数据格式的不一致使得在“大数据”框架（例如，机器学习应用程序）中难以利用。我们从各种不同的公共资源（包括文献和存储库）中收获了数千个稀疏的粘土矿物观察结果。我们以一种与机器学习兼容的方式对这些数据进行标准化。然后，我们利用机器学习算法来估计浅海海底（< 1 m）沉积物中主要粘土矿物的全球分布。最后，我们将我们的预测与之前发表的地图进行比较。我们的预测在描述上是相似的，但在统计上更准确。

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引用次数: 0

Sea-level and basement structural controls on Late Quaternary sedimentation in a tropical wave-dominated delta: Evidence from subsurface cores in Kaveri Delta, India 海平面和基底构造对热带波主导型三角洲晚第四纪沉积的控制：来自印度Kaveri三角洲地下岩心的证据

IF 2.2 3区地球科学 Q2 GEOSCIENCES, MULTIDISCIPLINARY

Marine Geology

Pub Date : 2026-02-01 Epub Date: 2025-12-24 DOI: 10.1016/j.margeo.2025.107700

Kartika Goswami , Linto Alappat , Manoj K. Jaiswal , Sivakumar Krishnan , Anbarasu Kumaresan , Senthil Kumar Sadasivam , Xianjiao Ou

The Kaveri (Cauvery) River delta on the southeast coast of India is among the largest sedimentary archives of peninsular India, preserving a complex record of sea-level fluctuations, fluvial dynamics, and tectonic controls in a tropical wave-dominated setting. This study presents results from four 25 m-deep sediment cores, analysed for chronology using quartz optically stimulated luminescence (OSL) dating, along with sedimentological characterisation and micropalaeontological (foraminiferal) analysis. Chronological data reveal four marine transgressions during MIS 5.5 (∼122 ka), MIS 5.1 (∼72 ka), MIS 3 (∼41 ka), and MIS 1 (9-6 ka). Corresponding foraminiferal assemblages confirm episodic marine influence well into the deltaic interior. Stratigraphic contrasts between inland and coastal cores indicate that the structural high along the Vedaranyam Ridge influenced accommodation space and sediment trapping within the adjoining Nagapattinam depression. Our findings emphasise that Late Quaternary delta development was governed by both allogenic (climate, sea level) and autogenic (sediment load, channel dynamics) processes. Notably, while Holocene sea-level records are relatively well documented, reliable evidence for Pleistocene highstands from the east coast of India remains sparse and discontinuous. By providing one of the few continuous stratigraphic and chronological records of multiple late Pleistocene highstands from the east coast of India, this study offers new insights into long-term deltaic response to external forcing in low-latitude coastal systems.

位于印度东南海岸的Kaveri （Cauvery）河三角洲是印度半岛最大的沉积档案之一，在热带波浪主导的环境中保存了海平面波动、河流动力学和构造控制的复杂记录。这项研究展示了四个25米深的沉积物岩心的结果，使用石英光学刺激发光（OSL）测年法分析了年代学，以及沉积学特征和微古生物学（有孔虫）分析。时间数据显示在MIS 5.5 （~ 122 ka）、MIS 5.1 （~ 72 ka）、MIS 3 （~ 41 ka）和MIS 1 （9-6 ka）期间发生了4次海侵。相应的有孔虫组合证实了海相对三角洲内部的影响。内陆岩心与沿海岩心的地层对比表明，沿Vedaranyam脊的构造高压影响了相邻Nagapattinam凹陷内的可容纳空间和沉积圈闭。我们的研究结果强调，晚第四纪三角洲的发育是由异体（气候、海平面）和自生（泥沙负荷、河道动力学）过程共同控制的。值得注意的是，虽然全新世的海平面记录相对较好，但来自印度东海岸的更新世高地的可靠证据仍然稀少且不连续。通过提供印度东海岸多个晚更新世高地的为数不多的连续地层和年代学记录之一，本研究为低纬度沿海系统中三角洲对外部强迫的长期响应提供了新的见解。

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引用次数: 0

Decadal shoreline variability in urban beaches: Contributions from structural changes, storms, and nourishments to tipping points 城市海滩的年代际海岸线变化：结构变化、风暴和营养对临界点的贡献

IF 2.2 3区地球科学 Q2 GEOSCIENCES, MULTIDISCIPLINARY

Marine Geology

Pub Date : 2026-02-01 Epub Date: 2025-11-25 DOI: 10.1016/j.margeo.2025.107683

J. Guillén, G. Simarro

The beaches of Barcelona are sediment-starved, heavily engineered, and subject to frequent human interventions. Over two decades of daily shoreline data obtained through video monitoring have yielded a comprehensive dataset, which is analysed to evaluate decadal shoreline dynamics, anthropogenic influences, and interactions with wave forcing across multiple urban beaches. Despite an overall erosive trend, shoreline retreat has been intermittently counteracted by periodic sand nourishments and the construction of coastal protection structures. A statistical definition of equilibrium shoreline position is introduced based on the frequency distribution of shoreline locations and potential drivers of abrupt shifts (“tipping points”) in shoreline behavior are identified. The analysis includes assessments of post-nourishment retreat rates and explores correlations between shoreline change and storm wave energy. While individual beach responses exhibit moderate correlation with wave energy, this relationship becomes more robust when data are aggregated over longer temporal windows or spatially across all beaches, highlighting the relevance of local controls. These findings provide a valuable first-order framework for anticipating shoreline behavior in urban beach settings and inform future coastal management strategies, although further refinement through advanced morphodynamic modeling is recommended to enhance predictive accuracy.

巴塞罗那的海滩缺乏沉积物，经过大量的工程设计，经常受到人类的干预。通过视频监测获得的20多年的每日海岸线数据产生了一个全面的数据集，分析该数据集以评估年代际海岸线动态，人为影响以及与多个城市海滩波浪强迫的相互作用。尽管总体上有侵蚀趋势，但海岸线的退缩已经被周期性的沙质滋养和海岸保护结构的建设间歇性地抵消了。基于岸线位置的频率分布，引入了平衡岸线位置的统计定义，并确定了岸线行为突变（“引爆点”）的潜在驱动因素。分析包括对营养后退缩率的评估，并探索海岸线变化与风暴波能量之间的相关性。虽然个别海滩的反应与波浪能量表现出适度的相关性，但当数据在较长的时间窗口或在所有海滩的空间上汇总时，这种关系变得更加强大，突出了局部控制的相关性。这些发现为预测城市海滩环境中的海岸线行为提供了一个有价值的一级框架，并为未来的海岸管理策略提供了信息，尽管建议通过先进的形态动力学建模进一步改进以提高预测准确性。

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引用次数: 0

Gran Roque Island partly submerged by a 2500-year-old tsunami, Los Roques Archipelago, Venezuela Leeward Antilles Islands 大罗克岛部分被2500年前的海啸淹没，委内瑞拉洛斯罗克群岛背风安的列斯群岛

IF 2.2 3区地球科学 Q2 GEOSCIENCES, MULTIDISCIPLINARY

Marine Geology

Pub Date : 2026-02-01 Epub Date: 2025-12-08 DOI: 10.1016/j.margeo.2025.107696

Franck A. Audemard M. , Carlos E. Reinoza Gómez , Jesús Rafael Padilla Vásquez , Melody Philippon , Gabriela Quintana Sánchez , Valerie Clouard , Jean Roger , Sirel Colón Useche , Alejandra Fabiola Leal Guzmán , José Alejandro Méndez Dot , Jean-Frédéric Lebrun

Gran Roque Island (GRI), as the most northeastern salient of the Los Roques Archipelago, has been affected by several extreme-wave events (EWEs), as is recorded by several coastal boulder deposits (CBDs). The particular shape of its windward elevated coast and of its rather simple geology made of 2-end components: on one hand Mesozoic meta-igneous mafic rocks, and on the other Holocene sedimentary environments of typical active carbonate reef systems, allow differentiating a foreshore-lying CBD built by frequent storm and hurricanes from an inland CBD, which was deposited by a much larger and unusual EWE (tsunami). The former CBD is the source of the latter one. The source of this tsunami-transported CBD is unequivocal and forms and accumulates in the seashore of the Mal Viento Bay, the only opening of GRI to the North. This latter singularity also allows proposing that this 2500 yr cal BP tsunami must have generated in the northeastern Caribbean, because of the narrow opening to the North of this bay. A tsunamigenic earthquake about that time seems to have impacted, at least: a) Saint Thomas (Virgin Islands), b) lagoon Guichard in Saint Martin, c) 3 localities along the Atlantic coast of Martinique and d) Gran Roque Island (GRI). This pre-Current Era event now appears to have several run-ups at different localities. In the case of GRI, it has entrained blocks of diabase as heavy as 8.5–9 tons (volume of 3 m³) over a foreshore top of 2.2 m above msl, requiring a flow depth of 8.2 m. In a more realistic estimation, if the largest block is approximated to a 1-m-diameter, 3-m-long cylinder (volume of 2.35 m³ and ≈ 7 tons), a 6.5 m tsunami wave may have been sufficient to transport it inland by rolling/saltation.

大罗克岛（GRI）作为洛斯罗克群岛最东北的突出部分，受到了几次极端波事件（ewe）的影响，这是几个海岸巨石沉积（CBDs）的记录。其迎风隆起海岸的特殊形状和由两部分组成的相当简单的地质构造：一方面是中生代变质火成岩基性岩，另一方面是全新世典型的活跃碳酸盐礁系统沉积环境，这使得它能够区分出一个由频繁的风暴和飓风形成的滨前CBD和一个由更大、更不寻常的海啸形成的内陆CBD。前者是后者的根源。这个由海啸带来的CBD的来源是明确的，它形成并积聚在Mal Viento海湾的海滨，这是GRI唯一向北开放的地方。后一个奇点也允许提出这个2500年前的海啸一定是在加勒比海东北部产生的，因为这个海湾的北部有一个狭窄的开口。大约在那个时候发生的海啸性地震似乎至少影响了：A)圣托马斯（维尔京群岛），b)圣马丁岛的吉查德泻湖，c)马提尼克岛大西洋沿岸的3个地方和d)格兰罗克岛（GRI）。这个前现代时代的事件现在似乎在不同的地方有几个运行。在GRI的情况下，它携带重达8.5-9吨（体积为3立方米）的辉绿岩块在msl以上2.2米的前海岸顶部，需要8.2米的水流深度。在更现实的估计中，如果最大的块体近似为直径1米、长3米的圆柱体（体积为2.35立方米，≈7吨），则6.5米的海啸波可能足以通过滚动/跳跃将其运送到内陆。

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引用次数: 0

Morphodynamics of a composite barrier system, Westward Ho!, North Devon, UK 一个复合势垒系统的形态动力学，向西Ho！，北德文郡，英国

IF 2.2 3区地球科学 Q2 GEOSCIENCES, MULTIDISCIPLINARY

Marine Geology

Pub Date : 2026-02-01 Epub Date: 2025-11-26 DOI: 10.1016/j.margeo.2025.107684

C.L. Rimmer, G. Masselink, M. Wiggins, L. Biermann

Understanding and predicting the morphodynamic evolution of gravel barrier systems is essential for coastal management, as these features provide natural protection for infrastructure and ecosystems. This study uses the composite gravel barrier system of Westward Ho!, south west England, characterised by a sandy intertidal region and a gravel high tide ridge, to quantify the morphological behaviour of this barrier system and link the dynamics to the external forcing, notably sea-level rise and waves. Since 1887, the barrier has retreated by 97 m, with an average retreat rate of 0.71 m yr⁻¹. Over the period 2007–2024, the system lost approximately 216,000 m³ of sediment, equivalent to 3.6 m³ m⁻¹ yr⁻¹. It is suggested that most of this material was transported to a beach-dune system north of the barrier, across an estuary. Over the past two decades, the retreat rate of the southern section has slowed to 0.18 m yr⁻¹, while the retreat rate of the northern section has increased to 2.39 m yr⁻¹. This suggests segmentation is occurring, with the southern end becoming swash-aligned and the northern end drift-aligned. Morphological changes did not strongly correlate with SLR or wave power (cross-shore or longshore). The low-tide shoreline appears near equilibrium with prevailing wave direction, but the gravel ridge is slightly misaligned, suggesting net northward sediment transport. Given current trends, the barrier is expected to continue retreating and losing sediment for several decades. However, a comprehensive understanding of the system's future behaviour requires development of a mixed-sediment morphodynamic model.

了解和预测砾石屏障系统的形态动力学演化对海岸管理至关重要，因为这些特征为基础设施和生态系统提供了自然保护。本研究采用西禾组复合砾石屏障体系。以沙质潮间带和砾石涨潮脊为特征的英格兰西南部，量化该屏障系统的形态行为，并将动力学与外部强迫联系起来，特别是海平面上升和海浪。自1887年以来，该屏障后退了97米，平均后退速度为0.71米/年。在2007-2024年期间，该系统损失了大约216000立方米的沉积物，相当于3.6立方米m−1年−1年。据推测，大部分这些物质被运输到屏障北部的海滩-沙丘系统，穿过河口。近20年来，南段退缩速度已减缓至0.18 m yr - 1，而北段退缩速度已增加至2.39 m yr - 1。这表明分割正在发生，南端变成斜向，北端变成漂向。形态变化与单反或波浪功率（跨岸或长岸）没有很强的相关性。低潮岸线与盛行波方向接近平衡，但砾石脊稍有错位，表明泥沙向北净输运。鉴于目前的趋势，预计在未来几十年里，这一屏障将继续后退并失去沉积物。然而，要全面了解该系统的未来行为，需要开发混合沉积物形态动力学模型。

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引用次数: 0

Sedimentary dynamics in the subaqueous delta of the abandoned estuary: Effects of strong wave activity and riverine re-supply 废弃河口水下三角洲的沉积动力学：强波活动和河流补给的影响

IF 2.2 3区地球科学 Q2 GEOSCIENCES, MULTIDISCIPLINARY

Marine Geology

Pub Date : 2026-01-01 Epub Date: 2025-10-08 DOI: 10.1016/j.margeo.2025.107662

Chaoran Lin , Longhai Zhu , Yaping Wang , Rui Bao , Rijun Hu , Lingpeng Meng

Global climate change and the decline in riverine sediment supply are profoundly reshaping the fate and trajectory of numerous river deltas around the world. Notably, subaqueous deltas of abandoned estuaries (SDAEs) resulting from river diversion represent an extreme example of zero riverine sediment supply, yet studies of these environments remain scarce. Based on in-situ bottom boundary layer observations in both spring and summer in the SDAE of the Yellow River, we examined the variation patterns and controlling mechanisms of sediment dynamics —under the effect of strong wave activity and the new secondary distribution. Strong wave events exhibited a pronounced dual influence on SSC; alongshore wave substantially increase SSC (>21.28 g/L) by enhancing sediment resuspension and liquefaction, whereas onshore wave significantly reduce nearshore SSC through water mass replacement (with values rapidly dropping from 13.11 g/L to 1.14 g/L). Riverine re-supply due to the new secondary course of the Yellow River has altered sediment transport pathways, enabling SSC in the SDAE to reach as high as 22.34 g/L under calm weather conditions, and resulting in a net alongshore sediment flux of 117 kg/m². We identified and established three conceptual models of fluid mud formation mechanisms: wave-supported, wave-current coupled fluid mud (WCFM), and river advection. We identified and established three conceptual models of fluid mud formation: wave-supported, wave-current coupled fluid mud (WCFM), and river advection. Identification of the WCFM highlights the sustained impact of strong wave activity on sediment transport within the SDAE. These findings advance our understanding of sediment dynamics in the SDAEs and provide valuable theoretical references and comparative examples for the studying the global evolution of abandoned or sediment-starved delta.

全球气候变化和河流沉积物供应的减少正在深刻地重塑世界各地众多河流三角洲的命运和轨迹。值得注意的是，河流改道导致的废弃河口水下三角洲（SDAEs）是河流沉积物零供应的一个极端例子，但对这些环境的研究仍然很少。基于黄河南岸河段春夏两季底边界层观测资料，探讨了强波活动和新的二次分布作用下泥沙动力的变化规律和控制机制。强波事件对SSC具有明显的双重影响；近岸波通过加强沉积物再悬浮和液化作用显著增加SSC (21.28 g/L)，而近岸波通过水体质量替代作用显著减少SSC（从13.11 g/L迅速下降到1.14 g/L）。黄河新次河道的河道再补给改变了输沙路径，使SDAE的SSC在平静天气条件下高达22.34 g/L，导致净岸沙通量为117 kg/m2。我们确定并建立了三种流体泥浆形成机制的概念模型：波支撑、波流耦合流体泥浆（WCFM）和河流平流。我们确定并建立了三种流体泥浆形成的概念模型：波支撑、波流耦合流体泥浆（WCFM）和河流平流。WCFM的确定强调了强波活动对SDAE内沉积物输运的持续影响。这些发现促进了我们对SDAEs沉积动力学的认识，并为研究遗弃或缺沙三角洲的全球演化提供了有价值的理论参考和比较实例。

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引用次数: 0

A submarine mud volcano eruption triggered a 100 m thick mass flow 海底泥火山爆发引发了100米厚的物质流

IF 2.2 3区地球科学 Q2 GEOSCIENCES, MULTIDISCIPLINARY

Marine Geology

Pub Date : 2026-01-01 Epub Date: 2025-11-05 DOI: 10.1016/j.margeo.2025.107680

Muhedeen A. Lawal, Ann E. Cook, Derek E. Sawyer

Offshore mud volcanoes can be sites of energetic eruptions and flank collapse. Using three dimensional seismic data from the Gulf of Mexico, we reveal an extensive mass flow (>1.1 × 10⁹ m³) that is linked to one of the region's largest and active mud volcanoes, the Kohl mud volcano. Our analysis reveals a collapsed southeastern crater flank that is ∼1300 m wide and marked by collapse scarps at Kohl. The resulting mass flow is characterized by basin-verging (∼16°) toe thrusts, widens downslope, and ends abruptly at a moat on the seafloor. Unlike typical thin, less cohesive mud volcano flows, this deposit is ∼100 m thick, extends ∼6000 m downslope, and originates from the failed southeastern flank. The deposit is bound by kilometer-scale faults that connect the collapse scarp upslope at the mud volcano crater, and exhibits localized erosion below its debris tongue, typical of mass transport deposits. Erosive and compressional behaviors define the terminal phase of the mass flow emplacement and likely reflect an energetic emplacement event. We argue that an energetic eruption and subsequent crater rim and flank collapse provides the most plausible explanation for our observations, highlighting the feedback between submarine mud volcanism and mass wasting. This study represents an important step forward for understanding how submarine mud volcanism influences the formation of thick and erosive mass flows and the processes that govern the emplacement of such flows on seafloors globally.

近海泥火山可能是剧烈喷发和侧翼塌陷的场所。利用来自墨西哥湾的三维地震数据，我们揭示了一个广泛的质量流（>1.1 × 109 m3），它与该地区最大和活跃的泥火山之一科尔泥火山有关。我们的分析揭示了一个塌陷的东南火山口侧面，大约1300米宽，在科尔以塌陷的悬崖为标志。由此产生的质量流的特征是盆地边缘（~ 16°）脚趾推力，下坡变宽，并在海底护城河处突然结束。不同于典型的薄的、粘性较低的泥火山流，该沉积物厚约100米，下坡延伸约6000米，起源于断裂的东南侧翼。该矿床被连接泥火山火山口上坡的崩塌陡坡的千米级断层所束缚，并在其碎屑舌下表现出局部侵蚀，这是典型的块体搬运矿床。侵蚀和挤压行为定义了质量流侵位的结束阶段，可能反映了一次高能侵位事件。我们认为，一次高能喷发和随后的火山口边缘和侧面塌陷为我们的观察提供了最合理的解释，突出了海底泥火山活动和大量消耗之间的反馈。这项研究是了解海底泥火山作用如何影响厚的侵蚀物质流的形成以及控制这些物质流在全球海底就位的过程的重要一步。

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引用次数: 0