A5064783580- Geological formations and processes
- Geology and Paleoclimatology Research
- Hydrology and Sediment Transport Processes
- Underwater Acoustics Research
- Geological and Geophysical Studies
- Geophysical Methods and Applications
- Particle Dynamics in Fluid Flows
- earthquake and tectonic studies
- Landslides and related hazards
- Methane Hydrates and Related Phenomena
- Coastal wetland ecosystem dynamics
- Soil erosion and sediment transport
- Granular flow and fluidized beds
- Coastal and Marine Dynamics
- Fluid Dynamics and Turbulent Flows
- Hydrocarbon exploration and reservoir analysis
- Ultrasonics and Acoustic Wave Propagation
- Aeolian processes and effects
- Flow Measurement and Analysis
- Underwater Vehicles and Communication Systems
- Oceanographic and Atmospheric Processes
- Geophysical and Geoelectrical Methods
- Nanofluid Flow and Heat Transfer
- Groundwater flow and contamination studies
- Coagulation and Flocculation Studies
University of Leeds
2016-2025
Cheshire West and Chester
2020
East Sussex County Council
2016
University of East Anglia
2000
Autonomous Underwater Vehicles (AUVs) have a wide range of applications in marine geoscience, and are increasingly being used the scientific, military, commercial, policy sectors. Their ability to operate autonomously host vessel makes them well suited exploration extreme environments, from world's deepest hydrothermal vents beneath polar ice sheets. They revolutionised our image seafloor, providing higher resolution seafloor mapping data than can be achieved surface vessels, particularly...
Abstract Flows with high suspended sediment concentrations are common in many sedimentary environments, and their flow properties may show a transitional behaviour between fully turbulent quasi‐laminar plug flows. The characteristics of these flows known to be function both clay concentration type, as well the applied fluid stress, but so far interaction loose bed has received little attention. Information on this type is essential for recognition prediction structures formed by cohesive in,...
Sediment fluxes in aquatic environments are crucially dependent on bedform dynamics. However, sediment-flux predictions rely almost completely clean-sand studies, despite most being composed of mixtures non-cohesive sands, physically cohesive muds and biologically extracellular polymeric substances (EPS) generated by microorganisms. EPS associated with surficial biofilms known to stabilize sediment increase erosion thresholds. Here we present experimental data showing that the pervasive...
Although analogies have been drawn between some types of meandering rivers and medium- to high-sinuosity, aggradational, leveed submarine channels, a number different or additional processes operate in channels. Analysis several individual channels suggests that they undergo much slower bend growth than alluvial may reach planform equilibrium, contrast rivers, which bends progressively migrate downstream. Sinuous should therefore aggrade produce isolated ribbons thalweg deposits (of...
Abstract New phase diagrams for the dynamic structure of clay-laden open-channel flows are proposed. These can be used to distinguish between turbulent Newtonian, transitional, and laminar non-Newtonian flow behavior, on basis balance forces (approximated by horizontal components velocity turbulence intensity) cohesive suspended clay concentration rheology). Stability regimes five different types defined using a comprehensive series laboratory flume experiments at depth-averaged velocities...
Abstract Co‐genetic debrite–turbidite beds occur in a variety of modern and ancient turbidite systems. Their basic character is distinctive. An ungraded muddy sandstone interval encased within mud‐poor graded sandstone, siltstone mudstone. The preserves evidence en masse deposition thus termed debrite. mudstone show features indicating progressive layer‐by‐layer are called turbidite. Palaeocurrent indicators, ubiquitous stratigraphic association the position hemipelagic intervals demonstrate...
Abstract Realistic physical models of meandering rivers have proven extremely difficult to produce, particularly in comparison the formation braided laboratory. Here we address question why such realistic model meanders are so reproduce, through most modeling channels yet achieved. This paper demonstrates that cohesion is a key variable development and maintenance single-thread channels. In particular, must be sufficient force planform away from state but low enough for active migration...
The use of sedimentary structures as indicators flow and sediment morphodynamics in ancient sediments lies at the very heart sedimentology, allows reconstruction formative conditions generated a wide range grain sizes environments. However, vast majority past research has documented detailed bedforms essentially cohesionless that lack presence mud within bed itself. Yet most environments possess fine-grained recent work shown how this fine may substantially modify fluid dynamics such flows....
Abstract Biologically active, fine‐grained sediment forms abundant sedimentary deposits on Earth's surface, and mixed mud‐sand dominates many coasts, deltas, estuaries. Our predictions of transport bed roughness in these environments presently rely empirically based form predictors that are exclusively biologically inactive cohesionless silt, sand, gravel. This approach underpins paleoenvironmental reconstructions successions, which analysis cross‐stratification bounding surfaces produced by...
The dimensions and dynamics of subaqueous bedforms are well known for cohesionless sediments. However, the effect physical cohesion imparted by cohesive clay within mixed sand-mud substrates has not been examined, despite its recognized influence on sediment stability. Here we present a series controlled laboratory experiments to establish substrate content bedform mixtures sand exposed unidirectional flow. results show that steepness decrease linearly with content, comparison existing...
Abstract Flutes and tool marks are commonly observed sedimentary structures on the bases of sandstones in deep‐water successions. These sole universally used as palaeocurrent indicators but, sharp contrast to most structures, they not palaeohydraulic reconstructions or aid prediction spatial distribution sediments. Since Kuenen's famous 1953 paper, flutes systems have been linked turbidity currents, reflected standard Bouma sequence taught generations geologists. Yet, these present a series...
Abstract Three sets of lock exchange experiments were run to look at the generation turbidity currents from debris flows. The flows ranged reasonably dilute (4% volumetric concentration) dense (40% with cohesive, non‐cohesive and mixed cohesive/non‐cohesive sediment. Concentration was measured one height using an Ultrasonic High Meter. Velocity Doppler Velocimetry Profiling 10 different heights in each run. resulting range plug well Comparison concentration profiles, velocity time–height...
Abstract: The frequency and origin of thickening-upward packages in the sediments deep-sea environments has been a topic much recent debate. Excellent bed-scale exposures Carboniferous Ross Formation, western Ireland, allow single surfaces to be traced laterally detailed architecture whole evaluated using multiple vertical logs. deposits comprise architectural elements including bed-sets, lobe-elements composite lobes, with being arranged depositional packages. Results show that these are...
A series of large-scale erosional scours are described from four modern deep-water canyon and/or channel systems along the northeast Atlantic continental margin. Regional-scale geophysical data indicate that most occur in zones rapid flow expansion, such as termini and margins. High-resolution images cover ∼25 km2 at 2 × m pixel size, were obtained depths 4200–4900 using Autosub6000, an autonomous underwater vehicle equipped with EM2000 multibeam bathymetry system. Sedimentological...
Research Article| May 07, 2018 Deep-water channel-lobe transition zone dynamics: Processes and depositional architecture, an example from the Karoo Basin, South Africa Hannah L. Brooks; Brooks † 1Stratigraphy Group, School of Earth Environment, University Leeds, LS2 9JT, UK †eehlb@leeds.ac.uk Search for other works by this author on: GSW Google Scholar David M. Hodgson; Hodgson Rufus Brunt; Brunt 2Stratigraphy Environmental Sciences, Manchester, M13 9PL, Jeff Peakall; Peakall Menno Hofstra;...
A detailed field investigation of a saline gravity current in the southwest Black Sea has enabled first complete analysis three-dimensional flow structure and dynamics series linked hydraulic jumps stratified, density-driven, flows. These observations were collected using an acoustic Doppler profiler mounted on autonomous underwater vehicle, reveal that internal mixing processes jumps, including expansion recirculation, provide previously unrecognised mechanism for grain-size sorting...
ABSTRACT Mixed grain‐size bedforms comprise alternating sand‐rich and poorly sorted mud‐rich laminae bands. These have been identified in distal submarine settings formed underneath unidirectional flows. This study documents mixed a proximal slope setting beneath both combined Core outcrop data with well‐constrained palaeogeographical context are used to describe two types of bedform. Type A current ripples low‐amplitude bed‐waves concave planar sandstone–mudstone foresets that pass into...
Research Article| October 01, 2005 Whole flow field dynamics and velocity pulsing within natural sediment-laden underflows James L. Best; Best 1Earth Biosphere Institute, School of Earth Environment, University Leeds, Leeds LS2 9JT, UK Search for other works by this author on: GSW Google Scholar Ray A. Kostaschuk; Kostaschuk 2Department Geography, Guelph, Ontario N1G 2W1, Canada Jeffrey Peakall; Peakall 3Earth Paul V. Villard; Villard 4Geomorphic Solutions, The Sernas Group Inc.,...