Particle-bearing currents in uniform density and two-layer fluids

Sutherland, Bruce; Gingras, Murray K.; Knudson, Calla; Steverango, Luke; Surma, Christopher

doi:10.1103/physrevfluids.3.023801

Cited by 21 publications

(16 citation statements)

References 30 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Experiments have shown that dilute (0.5–7 kg/m 3 ) river plumes entering saline water can settle toward the seabed by double diffusion or settling‐driven convection (Hoyal et al, , ; Jazi & Wells, ; Parsons et al, ; Sutherland et al, ). In these experiments turbidity currents were only generated when settling plumes had concentrations >1 kg/m 3 (Parsons et al, ).…”

Section: Discussionmentioning

confidence: 99%

“…(b) River discharge versus suspended load in 150 rivers worldwide (based on Mulder & Syvitski, 1995), with corresponding mechanisms described in previous studies and in this study. 10.1029/2019GL084526 Parsons et al, 2001;Sutherland et al, 2018). In these experiments turbidity currents were only generated when settling plumes had concentrations >1 kg/m 3 (Parsons et al, 2001).…”

Section: A Reduced Threshold Sediment Concentration For Generating Tumentioning

confidence: 99%

See 1 more Smart Citation

Direct Monitoring Reveals Initiation of Turbidity Currents From Extremely Dilute River Plumes

Hage

Cartigny

Sumner

et al. 2019

Geophysical Research Letters

View full text Add to dashboard Cite

Rivers (on land) and turbidity currents (in the ocean) are the most important sediment transport processes on Earth. Yet how rivers generate turbidity currents as they enter the coastal ocean remains poorly understood. The current paradigm, based on laboratory experiments, is that turbidity currents are triggered when river plumes exceed a threshold sediment concentration of ~1 kg/m3. Here we present direct observations of an exceptionally dilute river plume, with sediment concentrations 1 order of magnitude below this threshold (0.07 kg/m3), which generated a fast (1.5 m/s), erosive, short‐lived (6 min) turbidity current. However, no turbidity current occurred during subsequent river plumes. We infer that turbidity currents are generated when fine sediment, accumulating in a tidal turbidity maximum, is released during spring tide. This means that very dilute river plumes can generate turbidity currents more frequently and in a wider range of locations than previously thought.

show abstract

Section: Discussionmentioning

confidence: 99%

Section: A Reduced Threshold Sediment Concentration For Generating Tumentioning

confidence: 99%

Direct Monitoring Reveals Initiation of Turbidity Currents From Extremely Dilute River Plumes

Hage

Cartigny

Sumner

et al. 2019

Geophysical Research Letters

View full text Add to dashboard Cite

show abstract

“…So-called particle-laden flows can lead to double-diffusive fingering (Section 5) below the warm riverine intrusion (Davarpanah Jazi & Wells 2016). Once the particle-laden water has intruded into the interior of the receiving water body, the suspended sediment particles will settle out and the riverine water (without particles) may become lighter and cause convective plumes (Sutherland et al 2018).…”

Section: River Inflowsmentioning

confidence: 99%

Convection in Lakes

Bouffard

Wüest

2019

Annu. Rev. Fluid Mech.

104

View full text Add to dashboard Cite

Lakes and other confined water bodies are not exposed to tides, and their wind forcing is usually much weaker compared to ocean basins and estuaries. Hence, convective processes are often the dominant drivers for shaping mixing and stratification structures in inland waters. Due to the diverse environments of lakes—defined by local morphological, geochemical, and meteorological conditions, among others—a fascinating variety of convective processes can develop with remarkably unique signatures. Whereas the classical cooling-induced and shear-induced convections are well-known phenomena due to their dominant roles in ocean basins, other convective processes are specific to lakes and often overlooked, for example, sidearm, under-ice, and double-diffusive convection or thermobaric instability and bioconvection. Additionally, the peculiar properties of the density function at low salinities/temperatures leave distinctive traces. In this review, we present these various processes and connect observations with theories and model results.

show abstract

“…Settling-driven gravitational instabilities can affect the sedimentation from buoyant flows that are associated with various natural systems including river (hypopycnal) plumes (Hoyal et al, 1999b;Maxworthy, 1999;Parsons et al, 2001;Henniger and Kleiser, 2012;Davarpanah Jazi and Wells, 2016;Sutherland et al, 2018;Davarpanah Jazi and Wells, 2020), magma FIGURE 1 | Schematic representation of the mechanism by which settling-driven gravitational instabilities arise. (A) The particle suspension (gray) initially overlies particle-free fluid (blue) and the density profile is stable.…”

Section: Introductionmentioning

confidence: 99%

The Influence of Particle Concentration on the Formation of Settling-Driven Gravitational Instabilities at the Base of Volcanic Clouds

Fries

Lemus

Jarvis³

et al. 2021

Front. Earth Sci.

View full text Add to dashboard Cite

Settling-driven gravitational instabilities observed at the base of volcanic ash clouds have the potential to play a substantial role in volcanic ash sedimentation. They originate from a narrow, gravitationally unstable region called a Particle Boundary Layer (PBL) that forms at the lower cloud-atmosphere interface and generates downward-moving ash fingers that enhance the ash sedimentation rate. We use scaled laboratory experiments in combination with particle imaging and Planar Laser Induced Fluorescence (PLIF) techniques to investigate the effect of particle concentration on PBL and finger formation. Results show that, as particles settle across an initial density interface and are incorporated within the dense underlying fluid, the PBL grows below the interface as a narrow region of small excess density. This detaches upon reaching a critical thickness, that scales with (ν2/g′)1/3, where ν is the kinematic viscosity and g′ is the reduced gravity of the PBL, leading to the formation of fingers. During this process, the fluid above and below the interface remains poorly mixed, with only small quantities of the upper fluid phase being injected through fingers. In addition, our measurements confirm previous findings over a wider set of initial conditions that show that both the number of fingers and their velocity increase with particle concentration. We also quantify how the vertical particle mass flux below the particle suspension evolves with time and with the particle concentration. Finally, we identify a dimensionless number that depends on the measurable cloud mass-loading and thickness, which can be used to assess the potential for settling-driven gravitational instabilities to form. Our results suggest that fingers from volcanic clouds characterised by high ash concentrations not only are more likely to develop, but they are also expected to form more quickly and propagate at higher velocities than fingers associated with ash-poor clouds.

show abstract

Particle-bearing currents in uniform density and two-layer fluids

Cited by 21 publications

References 30 publications

Direct Monitoring Reveals Initiation of Turbidity Currents From Extremely Dilute River Plumes

Direct Monitoring Reveals Initiation of Turbidity Currents From Extremely Dilute River Plumes

Convection in Lakes

The Influence of Particle Concentration on the Formation of Settling-Driven Gravitational Instabilities at the Base of Volcanic Clouds

Contact Info

Product

Resources

About