Article
Geology
Justine Poppeschi, Kazushi Nakata, Hajime Naruse
Summary: Submarine leveed channels are common in submarine fans, but their formation parameters have not been studied. This study conducted four experimental series to simulate and study the conditions for the formation of submarine channels. The experiments showed that dilute flows can form purely depositional channel levees without erosive features. The formation of submarine channels is related to channel width and muddy suspended sediment.
Article
Physics, Fluids & Plasmas
Cheng-Hsien Lee, Jia-You Chen
Summary: This study investigates the effects of particle size and initial concentration on subaqueous granular collapse on an inclined plane. Experimental and numerical simulation results validate the multiphase model and reveal that particle size and initial concentration significantly affect the initial sliding volume and front speed.
PHYSICAL REVIEW FLUIDS
(2022)
Article
Mechanics
Jorge S. Salinas, S. Balachandar, Santiago L. Zuniga, M. Shringarpure, J. Fedele, D. Hoyal, M. Cantero
Summary: Gravity currents are studied in this work, focusing on the flow of a heavier fluid along the bottom of a sloping bed, beneath a stagnant lighter ambient fluid. The thickness of the current increases due to entrainment of ambient fluid. The rate of penetration of mean momentum, mean concentration, and turbulence-related quantities into the ambient fluid are analyzed, with a comparison to wall-bounded turbulent flows.
Article
Engineering, Geological
Hongwei Liu, Xiaoyan Zhao, Paolo Frattini, Giovanni Battista Crosta, Fabio Vittorio De Blasio, Yuhao Wan, Xuze Zhu
Summary: Rock avalanches are rapid and destructive flow-like movements of dry debris mass. This study conducted flume experiments to investigate the mobility and erosion of granular flows on an erodible substrate. The results showed that the properties of the substrate significantly influenced the flow dynamics, with total mass and grain size affecting both mobility and erosion effects.
ENGINEERING GEOLOGY
(2023)
Article
Geology
George Pantopoulos, Rafael Manica, Adam D. McArthur, Juliano Kuchle
Summary: The study focused on the fractionation of particles in deep-water sediment gravity flows, especially in experimental settings using coal and kaolin particles. The results show observable correlations between particle shape parameters, with circularity and roundness being dominant controls on shape variation. Additionally, differences in particle shape parameter distributions were observed in different areas within the experimental basin, especially in non-cohesive flow experiments.
Article
Materials Science, Multidisciplinary
M. Rusinowicz, G. Parry, F. Volpi, D. Mercier, S. Eve, U. Luders, F. Lallemand, M. Choquet, M. Braccini, C. Boujrouf, E. Hug, R. Coq Germanicus, M. Verdier
Summary: The mechanical study of a microelectronic-dedicated stack with Si3N4 and AlSiCu layers was conducted using nanoindentation and Finite Element Method (FEM) modeling. The damage process and cracking patterns were analyzed, with a novel procedure for identifying the Si3N4 layer tensile strength presented. The results were validated through observation of structure cross-sections with a Scanning Electron Microscope (SEM) after Focused Ion Beam (FIB) milling. The proposed identification procedure can be adapted to other systems with similar multiple-cracking patterns under indentation.
JOURNAL OF THE MECHANICS AND PHYSICS OF SOLIDS
(2022)
Article
Environmental Sciences
Mohammad Amir Khan, Nayan Sharma, Giuseppe Francesco Cesare Lama, Murtaza Hasan, Rishav Garg, Gianluigi Busico, Raied Saad Alharbi
Summary: This study investigates the hydrodynamic implications of braided rivers' geomorphological evolution, focusing on the three-dimensional turbulence structures generated around sediment bars. By measuring 3D velocity fields and analyzing 3D Turbulent Kinetic Energy components, the research sheds light on different flume-scale 3D turbulence structures and introduces the novel concept of 3D Hole Size analysis for extreme events separation.
Article
Geosciences, Multidisciplinary
R. Brighenti, L. Spaggiari, A. Segalini, R. Savi, G. Capparelli
Summary: This study presents results of laboratory tests on the impact of simulated debris flows on physical barrier models. The experimental setup allowed for varying channel inclination and barrier geometry, with results compared to a simplified analytical model to assess prediction capability and safety design of deformable protection barriers.
Article
Multidisciplinary Sciences
Sojiro Fukuda, Marijke G. W. de Vet, Edward W. G. Skevington, Elena Bastianon, Roberto Fernandez, Xuxu Wu, William D. McCaffrey, Hajime Naruse, Daniel R. Parsons, Robert M. Dorrell
Summary: Gravity currents, such as sediment-laden turbidity currents, are natural flows that are driven by a density difference. Material transport in gravity currents is fundamentally different from fluvial systems, and the current understanding is insufficient. Research shows that buoyancy production in gravity currents has a non-linear dependence on available flow power, indicating an underestimation of total kinetic energy lost.
NATURE COMMUNICATIONS
(2023)
Article
Mechanics
Ching-Sen Wu
Summary: This study investigates the evolution of bottom-propagating gravity currents with the presence of densified obstacles submerged in a channel using large-eddy simulations. The study finds that the submergence ratio and gap-spacing ratio of the obstacles significantly affect the propagation of gravity currents. Different flow morphologies are observed based on the values of these parameters. The study also reveals a turning point in the drag acting on the gravity current when the gap spacing exceeds a certain value. The propagation of the gravity current is not highly sensitive to the retarding effect and energy conversion is promoted.
Article
Mechanics
Dongrui Han, Yakun Guo, Pengcheng Jiao, Yeping Yuan, Ying-Tien Lin, Zhiguo He
Summary: This study investigates the effects of rough and porous bed and sedimentation processes on the characteristics of saline and turbidity currents. It finds that the local current concentration responds differently to turbulence bursting events, with saline currents having an immediate response while turbidity currents respond slowly. The study also examines the transfer of turbulent momentum fluxes in different directions and shows that the formation of sweep and ejection events depends on the directions of flux transfer. Additionally, the study explores the anisotropy of gravity currents and its sensitivity to the RP boundary and sedimentation processes.
Article
Geology
George Lu, Mathew Wells, Ian van Strygen, Robert E. Hecky
Summary: When a sediment laden river flows into a stratified water body, the water mass can intrude as an overflow, interflow or underflow, depending on the density contrast. Different modes of sediment driven convection occur in each case.
Article
Geology
Rebecca G. Englert, Stephen M. Hubbard, Matthieu J. B. Cartigny, Michael A. Clare, Daniel S. Coutts, Sophie Hage, John Hughes Clarke, Zane Jobe, D. Gwyn Lintern, Cooper Stacey, Daniela Vendettuoli
Summary: This study explores the formation and evolution of cyclic steps in deep-water sedimentary rocks through sedimentological and quantitative three-dimensional architectural analyses of modern and ancient datasets. It reveals similarities in deposit dimensions, facies, and architecture across different turbidite-dominated settings and timescales, shedding light on the stratigraphic expression of small-scale, sandy upslope-migrating bedforms on the seafloor.
Article
Geology
Jonathan Wilkin, Alan Cuthbertson, Sue Dawson, Dorrik Stow, Karl Stephen, Uisdean Nicholson, Nadia Penna
Summary: The transition between the slope and basin floor is marked by a slope break, causing channels to terminate and turbidity currents to lose confinement. Understanding how these slope breaks and losses of confinement influence the hydrodynamic evolution of turbidity currents and impact their deopositional variability is crucial. Flume experiments were conducted to study the impact of channel slope angle and initial suspended sediment concentrations on the hydrodynamics and deposit geometries of turbidity currents subject to a simultaneous slope break and loss of confinement. The results showed that turbidity currents increase their densimetric Froude numbers and shear velocities when encountering the slope break and loss of confinement.
Article
Engineering, Geological
Yan Li, Wei Hu, Janusz Wasowski, Yangshuai Zheng, Mauri McSaveney
Summary: Underestimating local scouring in loose cohesionless landslide deposits may lead to rapid and episodic failure of hazard mitigation structures. The erosion rate can be high and irreversible without artificial intervention once a hydraulic drop is formed, highlighting the importance of proper understanding and engineering solutions in erosion-sensitive deposits.
ENGINEERING GEOLOGY
(2021)