Journal of Geophysical Research: Earth Surface最新文献

Near Steady Late Pleistocene Tropical Denudation Rates in SW Madagascar 马达加斯加西南部近稳定的晚更新世热带剥蚀率

IF 3.5 2区地球科学

Journal of Geophysical Research: Earth Surface Pub Date : 2025-07-11 DOI: 10.1029/2024JF008147

Etienne Large, Julien Charreau, Pierre-Henri Blard, Germain Bayon, Eduardo Garzanti, Bernard Dennielou, Gwenaël Jouet, Natalia Vazquez Riveiros, Jacques Giraudeau, Laurie Reisberg, Aimeryc Shcumacher, Alfred Andriamamonjy, Amos Fety Michel Rakotondrazafy

{"title":"Near Steady Late Pleistocene Tropical Denudation Rates in SW Madagascar","authors":"Etienne Large, Julien Charreau, Pierre-Henri Blard, Germain Bayon, Eduardo Garzanti, Bernard Dennielou, Gwenaël Jouet, Natalia Vazquez Riveiros, Jacques Giraudeau, Laurie Reisberg, Aimeryc Shcumacher, Alfred Andriamamonjy, Amos Fety Michel Rakotondrazafy","doi":"10.1029/2024JF008147","DOIUrl":"https://doi.org/10.1029/2024JF008147","url":null,"abstract":"Denudation is a key parameter controlling the evolution of the Earth's surface, the production of soils, the stability of relief, or the long-term evolution of climate. Climate fluctuations conversely have a strong impact on denudation, but these complex feedback mechanisms are still under-constrained. To better predict future changes that will affect our habitat and understand the links between climate and denudation, precise quantification of paleo-denudation rates is required. In this work, we measure cosmogenic radionuclides (10Be) in turbidites of a well-dated marine sedimentary core recovered in the Mozambique Channel to provide a 900-ka long near-continuous record of paleo-denudation rates over the 100-ka climatic cycles. Neodymium isotopes and heavy mineral analysis were used to provide constraints on the provenance of terrigenous sediments exported from Madagascar to the studied site and show that temporal variations in sediment provenance are limited and decoupled from climatic cyclicity. Our 10Be-based paleo-denudation rates are in the same order as modern rates, ranging from 17.4 ± 5.8 mm/ka to 73.9 ± 29.4 mm/ka (1 standard deviation), and do not show major variations through the Middle and Late Pleistocene. Importantly, we did not identify a systematic significant impact of glacial/interglacial cyclicity on denudation rates. Denudation of this subtropical island may instead have been controlled by variability of monsoon intensity associated with shifts in the Inter Tropical Convergence Zone, but this interpretation remains speculative at this stage as it cannot be recorded within the resolution of cosmogenic-derived denudation rates.","PeriodicalId":15887,"journal":{"name":"Journal of Geophysical Research: Earth Surface","volume":"130 7","pages":""},"PeriodicalIF":3.5,"publicationDate":"2025-07-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2024JF008147","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144598421","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Controlling Factors on Water and Sediment Partitioning at Deltaic Bifurcations 三角洲分岔区水沙分配的控制因素

IF 3.5 2区地球科学

Journal of Geophysical Research: Earth Surface Pub Date : 2025-07-09 DOI: 10.1029/2024JF008152

Gabriele Barile, Paola Passalacqua, Siyoon Kwon, Marco Tubino

{"title":"Controlling Factors on Water and Sediment Partitioning at Deltaic Bifurcations","authors":"Gabriele Barile, Paola Passalacqua, Siyoon Kwon, Marco Tubino","doi":"10.1029/2024JF008152","DOIUrl":"https://doi.org/10.1029/2024JF008152","url":null,"abstract":"Bifurcations in river-dominated deltas are the main actors in the routing of water and sediments throughout the fluvial network. In spite of previous acknowledgments of their importance, we still lack a comprehensive framework on how bifurcation geometry affects water and sediment partitioning. To investigate this issue, we first combine previously calibrated 2D hydrodynamic simulations on the Wax Lake Delta with a Lagrangian particle-tracking model, quantifying the partitioning of water and sediments with different buoyancy at five bifurcations and their correlations with differences in channel width, branching angle and inlet bed elevation between the downstream branches. We compare the sediment partitioning at bifurcations with available field data to validate our methodology. We then employ the same modeling tools on a simplified geometry, whose geometrical and hydraulic features resemble those of the bifurcations in the Wax Lake Delta. Model results show that the branching angle does not affect the partitioning of water and sediments. The combined effect of asymmetries in the channel width and inlet bed elevation is captured by a simple linear formula that accurately estimates the partitioning of water at bifurcations returned by the 2D calibrated hydrodynamic simulations. Our results also highlight the key role played by transverse gradients in the bathymetry of the upstream channel in determining the partitioning of sediments, suggesting that deeper portions of the cross-section of the upstream channel can cause a proportionately larger fraction of sediments with a larger Rouse number to be routed toward the corresponding bifurcate.","PeriodicalId":15887,"journal":{"name":"Journal of Geophysical Research: Earth Surface","volume":"130 7","pages":""},"PeriodicalIF":3.5,"publicationDate":"2025-07-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2024JF008152","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144581983","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Interplay of Freeze-Thaw Cycles and Avalanche Impact on Glacial Landslide-Debris Flow Geohazard Chain in the Southeastern Tibetan Plateau 冻融循环与雪崩对青藏高原东南部冰川滑坡-泥石流地质灾害链的影响

IF 3.5 2区地球科学

Journal of Geophysical Research: Earth Surface Pub Date : 2025-07-07 DOI: 10.1029/2024JF008052

Taosheng Huang, Tengfei Wang, Limin Zhang, Dalei Peng, Ping Shen

{"title":"Interplay of Freeze-Thaw Cycles and Avalanche Impact on Glacial Landslide-Debris Flow Geohazard Chain in the Southeastern Tibetan Plateau","authors":"Taosheng Huang, Tengfei Wang, Limin Zhang, Dalei Peng, Ping Shen","doi":"10.1029/2024JF008052","DOIUrl":"https://doi.org/10.1029/2024JF008052","url":null,"abstract":"Southeast Tibet suffers increasing hyper-mobility cascading geohazards, especially during the warm season. The glacial debris flow on 10 September 2020 in the Zelunglung Basin, transformed from a moraine landslide, exemplifies such geohazards, yet the landslide initiation or evolution process remained obscure. Literature deduced rock-ice avalanche can trigger moraine landslides and freeze-thaw cycles modify moraine deposit integrity, but their interplay effect is rarely touched. Here, we combined satellite remote-sensing, post-event investigation and multi-physics modeling to reveal these questions. Field investigations and satellite data suggest that a small rock-ice avalanche likely triggered a moraine landslide, setting off the cascading event with the evolution process as a small rock-ice avalanche (0.45-Mm3) → impact on moraine deposit → moraine landslide (1.14-Mm3) → glacial debris flow, where avalanching-moraine landslide is the key link, regarding the volume amplifying effect. Utilizing multi-physics modeling, we explored the interplay of freeze-thaw cycles and avalanche impacts on moraine deposit stability. Numerical results validate the avalanche as a primary instigator. Under such avalanche impacts, moraine deposits predominantly fail in warm seasons. Elevated water content from ice melting within moraine deposits, intensified during thawing and restrained during freezing, creates a conducive environment for excess pore pressure build-up and subsequent liquefaction when subjected to avalanche stresses, leading to transformation to debris flows. Thus, the seasonal freeze-thaw cycles exhibit a control effect on the key link and the whole chain. Our findings suggest increasing attention to potential locations of rock-ice avalanches through earth observation and seismic monitoring systems for hazard prediction and risk mitigation, particularly in warm seasons.","PeriodicalId":15887,"journal":{"name":"Journal of Geophysical Research: Earth Surface","volume":"130 7","pages":""},"PeriodicalIF":3.5,"publicationDate":"2025-07-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144573450","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Geomorphic Response to Extreme Flooding in Northern Yellowstone National Park, USA 美国黄石国家公园北部极端洪水的地貌响应

IF 3.5 2区地球科学

Journal of Geophysical Research: Earth Surface Pub Date : 2025-07-05 DOI: 10.1029/2024JF008215

Zachary P. DeLuca, Andrew C. Wilcox, Lyman P. Persico

{"title":"Geomorphic Response to Extreme Flooding in Northern Yellowstone National Park, USA","authors":"Zachary P. DeLuca, Andrew C. Wilcox, Lyman P. Persico","doi":"10.1029/2024JF008215","DOIUrl":"https://doi.org/10.1029/2024JF008215","url":null,"abstract":"Understanding and predicting flood-induced geomorphic change, and the relative influences of fluvial forces and valley-bottom geometry on system response, are persistent quandaries in geomorphic-process studies. We combined field surveys, remote sensing, and hydraulic modeling to assess the geomorphic effects of the June 2022 flooding in northern Yellowstone National Park, in the western United States, which was by far the largest recorded flood at nearby gaging stations and caused extensive damage to park infrastructure. We evaluate geomorphic response relative to two ways of calculating the hydraulic forcing produced by the flood: unit stream power and impulse, a metric that incorporates flow duration, grain size, channel-bed slope, flood depth, and a threshold based on threshold channel theory. Measurements of pre- and post-flood active-channel width change captured the geomorphic response associated with deposition- and erosion-related channel migration. The geomorphic response to flooding showed substantial variability. Notable lateral channel erosion in some cases occurred in areas of high flow strength, such as high-gradient reaches, but elsewhere was concentrated along erodible channel margins and/or downstream of confluences, where calculated flow forces were unremarkable. Channel widening was greater in partially confined reaches than in unconfined or confined reaches, and channel areas of extensive deposition were associated with decreases in valley-bottom confinement. Low-gradient, unconfined reaches where flood flow spread across floodplains showed little evidence of the passage of a historic flood. As climate change increases the propensity for hydroclimatic extremes and events such as the Yellowstone flood, investigation of links between flood forcings and geomorphic response is particularly important.","PeriodicalId":15887,"journal":{"name":"Journal of Geophysical Research: Earth Surface","volume":"130 7","pages":""},"PeriodicalIF":3.5,"publicationDate":"2025-07-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144558008","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Predicting the Three-Dimensional Stratigraphy of an Ice Rise 预测一次冰升的三维地层学

IF 3.5 2区地球科学

Journal of Geophysical Research: Earth Surface Pub Date : 2025-07-04 DOI: 10.1029/2024JF007924

A. C. J. Henry, C. Schannwell, V. Višnjević, J. Millstein, P. D. Bons, O. Eisen, R. Drews

{"title":"Predicting the Three-Dimensional Stratigraphy of an Ice Rise","authors":"A. C. J. Henry, C. Schannwell, V. Višnjević, J. Millstein, P. D. Bons, O. Eisen, R. Drews","doi":"10.1029/2024JF007924","DOIUrl":"https://doi.org/10.1029/2024JF007924","url":null,"abstract":"Ice rises located in ice shelves around Antarctica act as pinning points, impeding the flow of ice in ice shelves and in the upstream ice sheet. Ice rises preserve records of past climate and associated changes in ice flow in their stratigraphy. Typically, the flow of ice in ice rises is characterized by both converging and diverging patterns, experiencing transitions from contact with bathymetric features to floating on the ocean. In this study, we develop a three-dimensional ice flow model that is capable of simulating the internal stratigraphy of ice rises. The modeled stratigraphy can be compared with observed stratigraphy inferred from ground-penetrating radar observations. The model simulates three-dimensional ice flow described by the Stokes equations and evolution of ice temperature described by an advection-diffusion equation that impacts the non-linear ice rheology. We use our model to simulate the observed stratigraphy of Derwael Ice Rise in Dronning Maud Land, East Antarctica. Our results show a close agreement with the observed ice stratigraphy and suggest that the ice at 5% above the base is approximately 8,000 years old. Our new model enables us to relate the observed ice-rise stratigraphy to the ice flow and its changes.","PeriodicalId":15887,"journal":{"name":"Journal of Geophysical Research: Earth Surface","volume":"130 7","pages":""},"PeriodicalIF":3.5,"publicationDate":"2025-07-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2024JF007924","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144551085","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Seismic Evidence of Impact Breccia and Unlithified Sediments Under Hiawatha Glacier 海瓦塔冰川下冲击角砾岩和未岩化沉积物的地震证据

IF 3.5 2区地球科学

Journal of Geophysical Research: Earth Surface Pub Date : 2025-07-01 DOI: 10.1029/2024JF008247

Rishi Chandra, Kiya L. Riverman, Daniella N. DellaGiustina, Erin C. Pettit, Nicholas C. Schmerr, Georgia Carroll, Veronica J. Bray, S. Hop Bailey

{"title":"Seismic Evidence of Impact Breccia and Unlithified Sediments Under Hiawatha Glacier","authors":"Rishi Chandra, Kiya L. Riverman, Daniella N. DellaGiustina, Erin C. Pettit, Nicholas C. Schmerr, Georgia Carroll, Veronica J. Bray, S. Hop Bailey","doi":"10.1029/2024JF008247","DOIUrl":"https://doi.org/10.1029/2024JF008247","url":null,"abstract":"Hiawatha Crater in northwest Greenland is one of only two putative impact craters under an ice sheet. Hiawatha therefore offers a rare proxy for understanding the interactions between active glacial dynamics and impact craters on other planetary bodies. Here we characterize Hiawatha's subglacial environment, presenting the results of two active-source seismic experiments and interpreting them in concert with previous radar sounding analysis. Seismic reflectivities at a site with a single basal radar reflector are consistent with a substrate of impact melt-bearing breccia. At a site where radar sounding revealed a porewater reflector 10–15 m below the base of the ice sheet, our seismic results are consistent with a substrate of unlithified sediments. We propose a model where supraglacial water supplies heat for basal melting, leading to rain–out of unconsolidated sediment from debris-rich basal ice (fringe) and permitting a permeable porewater-bearing basal layer to persist without consolidating.","PeriodicalId":15887,"journal":{"name":"Journal of Geophysical Research: Earth Surface","volume":"130 7","pages":""},"PeriodicalIF":3.5,"publicationDate":"2025-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2024JF008247","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144519869","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Impacts of Exotic Saltmarsh Vegetation Removal and Native Saltmarsh Vegetation Restoration on Bed Level Change and Surficial Sediment Distribution in an Estuary Wetland 外来盐沼植被清除和原生盐沼植被恢复对河口湿地河床变化和表层沉积物分布的影响

IF 3.5 2区地球科学

Journal of Geophysical Research: Earth Surface Pub Date : 2025-06-30 DOI: 10.1029/2024JF008119

Yiming Wu, Zeng Zhou, Chuning Dong, Hang Zheng, Wenbo Lin, Jujuan Gao, Pingping Guo, Yuxian Gu, Tongchao Le, Karin R. Bryan

{"title":"Impacts of Exotic Saltmarsh Vegetation Removal and Native Saltmarsh Vegetation Restoration on Bed Level Change and Surficial Sediment Distribution in an Estuary Wetland","authors":"Yiming Wu, Zeng Zhou, Chuning Dong, Hang Zheng, Wenbo Lin, Jujuan Gao, Pingping Guo, Yuxian Gu, Tongchao Le, Karin R. Bryan","doi":"10.1029/2024JF008119","DOIUrl":"https://doi.org/10.1029/2024JF008119","url":null,"abstract":"The invasion of exotic saltmarsh species precipitates the degradation of native estuarine wetlands. In response, saltmarsh restoration projects, which concentrate on removing exotic saltmarsh species and replanting native ones, have been widely adopted to protect wetland biodiversity and restore ecosystem services. However, the morphological and sedimentary responses of wetlands during the restoration process remain unclear. This study investigates the impacts of saltmarsh restoration on bed level changes and surficial sediment distribution in the Shanyutan Wetland, Southeast China. A biomorphodynamic model is developed that integrates a remote-sensing-informed vegetation module with hydrodynamics and sediment transport processes. This model is used to explore the drivers of these morphodynamic changes and to understand the underlying mechanisms. Model results indicate that the removal of exotic saltmarshes induces erosion along saltmarsh edges and within zones near tidal channels, accompanied by a reduction in mud content. Meanwhile, the interior saltmarsh areas experience a modest increase in mud accumulation. The influence of this removal extends beyond the initial removed site, leading to sand deposition seawards of the salt marsh. Replanting native species contributes to an average increase in bed elevation, though it shows limited efficacy in enhancing mud content. These findings suggest that while wetland elevation may recover from the initial erosion induced by vegetation removal to reach a pre-removal state within 1–3 years, restoring sediment distribution by native saltmarsh replanting remains challenging. Overall, this research deepens our understanding of morphodynamic responses during estuarine wetland restoration and offers critical insights for landscape reconstruction in wetland management.","PeriodicalId":15887,"journal":{"name":"Journal of Geophysical Research: Earth Surface","volume":"130 7","pages":""},"PeriodicalIF":3.5,"publicationDate":"2025-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144514774","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Numerical Simulation of Sound-Side Barrier-Island Inundation and Breaching During Hurricane Dorian (2019) 飓风“多里安”（2019）期间声侧屏障-岛屿淹没与决口的数值模拟

IF 3.5 2区地球科学

Journal of Geophysical Research: Earth Surface Pub Date : 2025-06-20 DOI: 10.1029/2025JF008309

John C. Warner, Christopher R. Sherwood, Christie A. Hegermiller, Zafer Defne, Joe Zambon, Ruoying He, George Xue, Daoyang Bao, Dongxiao Yin, Melissa Moulton

{"title":"Numerical Simulation of Sound-Side Barrier-Island Inundation and Breaching During Hurricane Dorian (2019)","authors":"John C. Warner, Christopher R. Sherwood, Christie A. Hegermiller, Zafer Defne, Joe Zambon, Ruoying He, George Xue, Daoyang Bao, Dongxiao Yin, Melissa Moulton","doi":"10.1029/2025JF008309","DOIUrl":"https://doi.org/10.1029/2025JF008309","url":null,"abstract":"Hurricane-induced morphological changes and associated community hazards along sandy, barrier-island coastlines have been studied primarily from the perspective of ocean-side attack by storm-driven ocean surge and large waves. Thus, our understanding of long-term barrier island morphological change focuses on beach erosion, overwash, and inlet formation. In contrast, outwash events with inundation from the sound side, such as one that occurred in Cape Lookout National Seashore, North Carolina, USA during Hurricane Dorian (September 2019), are understudied. Studying such events can improve understanding of barrier island response and stability for a broader range of conditions. Here, we model the hydrodynamics and morphological evolution of a barrier island using a coupled wave-current-sediment transport modeling system. Wind-driven surge in Pamlico Sound led to overtopping from the sound side, which eroded outwash channels and transported sediment seaward into the nearshore. Simulations reproduce the channel features observed with aerial imagery and provide information not available from the remote-sensing observations, including channel depths (>2 m) and the fate of the eroded sand. We found that >99% of the eroded sand was deposited in the nearshore, within 1,000 m of the shoreline in depths <10 m, suggesting that the deposited sediment remains available for littoral transport and beach recovery. Simulations with combinations of coarse or fine sediment and vegetated or unvegetated landcover indicate that channel position did not vary with grain size or vegetation, while volume of erosion and channel morphology were more responsive to variations in grain size and less responsive to presence of vegetation.","PeriodicalId":15887,"journal":{"name":"Journal of Geophysical Research: Earth Surface","volume":"130 6","pages":""},"PeriodicalIF":3.5,"publicationDate":"2025-06-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2025JF008309","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144331803","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Impact of Interfacial Friction at the Ice-Bed Boundary on Glacier Sliding 冰床边界界面摩擦对冰川滑动的影响

IF 3.5 2区地球科学

Journal of Geophysical Research: Earth Surface Pub Date : 2025-06-18 DOI: 10.1029/2022JF007028

J. P. Roldán-Blasco, F. Gimbert, O. Gagliardini, A. Gilbert

{"title":"Impact of Interfacial Friction at the Ice-Bed Boundary on Glacier Sliding","authors":"J. P. Roldán-Blasco, F. Gimbert, O. Gagliardini, A. Gilbert","doi":"10.1029/2022JF007028","DOIUrl":"https://doi.org/10.1029/2022JF007028","url":null,"abstract":"Current theories for describing glacier sliding over hard beds assume that basal drag is entirely due to normal forces acting on meter-scale bed roughness and neglect tangential friction at the ice-bed interface. However, this interfacial friction is likely to account for a significant proportion of basal drag in the presence of basal debris or cold ice, and may render current sliding theories inaccurate. The aim of the study is to evaluate if current sliding laws still apply in the presence of interfacial friction. We propose a simplified analytical model of glacier sliding controlled by both ice creep around bed irregularities, as proposed by Weertman (1957, https://doi.org/10.3189/s0022143000024709), and interfacial friction at the ice-bed boundary determined by Coulomb dependency. We show that reduced sliding speed from additional interfacial friction is mitigated by increased ice deformation near the bed, which occurs as a result of additional basal deviatoric stresses reducing the effective viscosity. We further generalize these results using a numerical model of glacier sliding over a sinusoidal bed, capable of simulating cavity formation and basal sliding with several formulations of interfacial friction. We find that the additional friction generally does not modify the form of previously proposed friction laws but significantly increases the maximum resistive shear stress of the bed. These results suggest that friction laws that are commonly used in ice-sheet models and whose parameters are empirically optimized, could be still used in circumstances where interfacial friction is non-negligible.","PeriodicalId":15887,"journal":{"name":"Journal of Geophysical Research: Earth Surface","volume":"130 6","pages":""},"PeriodicalIF":3.5,"publicationDate":"2025-06-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2022JF007028","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144309173","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Direct Interception of Particles by a Vegetation Stem With Varying Adhesive Forces 具有不同粘附力的植物茎直接拦截颗粒

IF 3.5 2区地球科学

Journal of Geophysical Research: Earth Surface Pub Date : 2025-06-17 DOI: 10.1029/2024JF007915

Mahdi Khademishamami, Lawrence Sanford, William Nardin, Elizabeth North

{"title":"Direct Interception of Particles by a Vegetation Stem With Varying Adhesive Forces","authors":"Mahdi Khademishamami, Lawrence Sanford, William Nardin, Elizabeth North","doi":"10.1029/2024JF007915","DOIUrl":"https://doi.org/10.1029/2024JF007915","url":null,"abstract":"The direct interception of particles by vegetation stems has been reported in field studies of saltmarsh platforms as a major cause for removing suspended particles and pollutants. Laboratory observations and numerical models reported in the literature have computed the attachment efficiency under the assumption that particles stick and do not move when they collide with the surface of the collector (i.e., perfect attachment). This study was aimed at lifting this assumption using a Discrete Element Model (DEM) with varying adhesive contact forces coupled with Computational Fluid Dynamics (CFD). The CFD-DEM model considers the stickiness of the collector through a surface energy parameter. Model predictions showed good agreement with laboratory observations. The final configuration of particles on the collector's surface and the attachment efficiency changed when the collector's surface energy was varied. In some cases, the attachment efficiency was twice that under the perfect attachment assumption, indicating that modeling studies with perfect attachment may underestimate suspended particle removal. As biofilms are considered the main cause of the adhesiveness of stems, our study shows that any biofilm formation that could create a surface energy as low as 0.01 <math>\u0000 <semantics>\u0000 <mrow>\u0000 <mtext>mJ</mtext>\u0000 <mo>/</mo>\u0000 <msup>\u0000 <mi>m</mi>\u0000 <mn>2</mn>\u0000 </msup>\u0000 </mrow>\u0000 <annotation> $text{mJ}/{mathrm{m}}^{2}$</annotation>\u0000 </semantics></math> could lead to attachment of particles on a single saltmarsh stem.","PeriodicalId":15887,"journal":{"name":"Journal of Geophysical Research: Earth Surface","volume":"130 6","pages":""},"PeriodicalIF":3.5,"publicationDate":"2025-06-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2024JF007915","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144300293","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0