The response of turbidity currents to a canyon–fan transition: internal hydraulic jumps and depositional signatures

Kostic, Svetlana; Parker, Gary

doi:10.1080/00221686.2006.9521713

Cited by 134 publications

(197 citation statements)

References 38 publications

Supporting

Mentioning

188

Contrasting

Order By: Relevance

“…Similarly, numerical model developed by Kostic and Parker 14) has been applied to Monterey Submarine Channel off Monterey, California by Fildani, aided to conclude that the sediment waves on the outside levee of the Shepard bend appear to be net depositional cyclic steps 15) . Outcomes of this numerical study further concreted the idea that the sediment waves observed on the levees of many other submarine channels should probably be cyclic steps, perfectly agreeing with previuos research results 13),16), 17) . Numerical model proposed by Kostic and Parker based on "fourequation model" 18) , provided an insight into what can be expected once cyclic steps generated by turbidity currents in an experimental setting 19) .…”

Section: I_503supporting

confidence: 64%

Cyclic steps formed by turbidity currents

Dias

Izumi

Yokokawa

2011

J. JSCE

View full text Add to dashboard Cite

Levees of channels formed due to turbidity currents on submarine fans are often covered with step like bedforms. Circumstantial evidences emerged with numerical and experimental studies have suggested these sediment waves should probably be cyclic steps. The formation of cyclic steps in sub-aqueous environments through a mathematical perspective is presented in this research. A mathematical model preserving essential physics of the system is solved for one step wave length to obtain a preserved step shape of upstream migrating steps and the behavior of characteristic parameters governing this cyclic step formation phenomenon.

show abstract

Section: I_503supporting

confidence: 64%

Cyclic steps formed by turbidity currents

Dias

Izumi

Yokokawa

2011

J. JSCE

View full text Add to dashboard Cite

show abstract

“…7 and 8), with mean paleoflow toward the northeast. Lenticular erosive features in the Baviaans area may represent either: shallow scours, often associated with channel-lobe transition zones (e.g., Wynn et al, 2002;Macdonald et al, 2011aMacdonald et al, , 2011bHofstra et al, 2015;Pemberton et al, 2016;Brooks et al, 2018b) formed by hydraulic jumps where flows transition from super-to subcritical due to a reduction in slope gradient and/or flow confinement (Mutti andNormark, 1987, 1991;Weirich, 1989;Kostic and Parker, 2006;Sumner et al, 2013;Dorrell et al, 2016); or weakly confined distributive channels eroding into proximal lobes, with distributive patterns likely due to the reduction of slope gradient (e.g., van der Werff and . These characteristics indicate deposition in a base-of-slope area.…”

Section: Discussionmentioning

confidence: 99%

Disconnected submarine lobes as a record of stepped slope evolution over multiple sea-level cycles

et al. 2018

View full text Add to dashboard Cite

The effects of abrupt changes in slope angle and orientation on turbidity current behavior have been investigated in numerous physical and numerical experiments and examined in outcrop, subsurface, and modern systems. However, the long-term impact of subtle and evolving seabed topography on the stratigraphic architecture of deep-water systems requires fine-scale observations and extensive 3-D constraints. This study focuses on the Permian Laingsburg and Fort Brown formations, where multiple large sand-rich systems (Units A-F) have been mapped from entrenched slope valleys, through channel-levee systems, to basin-floor lobe complexes over a 2500 km 2 area. Here, we investigate three thinner (typically <5 m in thickness) and less extensive sand-rich packages, Units A/B, B/C, and D/E, between the large-scale systems. Typically, these sand-rich units are sharp-based and topped, and contain scours and mudstone clast conglomerates that indicate deposition from high-energy turbidity currents. The mapped thickness and facies distribution suggest a lobate form. These distinctive units were deposited in similar spatial positions within the basin-fill and suggest similar accommodation patterns on the slope and basin floor prior to the larger systems (B, C, and E). Stratigraphically, these thin units represent the first sand deposition following major periods of shut-down in sediment supply, and are interpreted as marking a partial re-establishment of sand delivery pathways creating "disconnected lobes" that are fed mainly by flows sourced from failures on the shelf and upper slope rather than major feeder channel-levee systems.Thickness and facies patterns throughout the deep-water stratigraphy suggest seabed topography was present early in the basin formation and maintained persistently in a similar area to ultimately form a stepped slope profile. The stepped slope profile evolved through three key stages of development: Phase 1, where sediment supply exceeds deformation rate (likely caused by differential subsidence); Phase 2, where sediment supply is on average equal to deformation rate; and Phase 3, where deformation rate outpaces sediment supply. This study demonstrates that smaller systems are a sensitive record of evolving seabed topography and they can consequently be used to recreate more accurate paleotopographic profiles.

show abstract

“…Recent flume and numerical models indicate that supercritical flows can produce upstream-migrating asymmetric bedforms with a wide range of scales (Figs. 5, 6;Sun and Parker 2005;Kostic and Parker 2006;Fildani et al 2006;Spinewine et al 2009;Cartigny et al 2011;Kostic 2011;). They provide a potential explanation for bedforms seen in fjord-head deltas (Figs.…”

Section: (B) Supercritical-flow Dynamics and Depositsmentioning

confidence: 99%

Key Future Directions For Research On Turbidity Currents and Their Deposits

Talling

Allin

Armitage

et al. 2015

Journal of Sedimentary Research

163

117

View full text Add to dashboard Cite

Turbidity currents, and other types of submarine sediment density flow, redistribute more sediment across the surface of the Earth than any other sediment flow process, yet their sediment concentration has never been measured directly in the deep ocean. The deposits of these flows are of societal importance as imperfect records of past earthquakes and tsunamogenic landslides and as the reservoir rocks for many deep-water petroleum accumulations. Key future research directions on these flows and their deposits were identified at an informal workshop in September 2013. This contribution summarizes conclusions from that workshop, and engages the wider community in this debate. International efforts are needed for an initiative to monitor and understand a series of test sites where flows occur frequently, which needs coordination to optimize sharing of equipment and interpretation of data. Direct monitoring observations should be combined with cores and seismic data to link flow and deposit character, whilst experimental and numerical models play a key role in understanding field observations. Such an initiative may be timely and feasible, due to recent technological advances in monitoring sensors, moorings, and autonomous data recovery. This is illustrated here by recently collected data from the Squamish River delta, Monterey Canyon, Congo Canyon, and offshore SE Taiwan. A series of other key topics are then highlighted. Theoretical considerations suggest that supercritical flows may often occur on gradients of greater than , 0.6u. Trains of up-slope-migrating bedforms have recently been mapped in a wide range of marine and freshwater settings. They may result from repeated hydraulic jumps in supercritical flows, and dense (greater than approximately 10% volume) near-bed layers may need to be invoked to explain transport of heavy (25 to 1,000 kg) blocks. Future work needs to understand how sediment is transported in these bedforms, the internal structure and preservation potential of their deposits, and their use in facies prediction. Turbulence damping may be widespread and commonplace in submarine sediment density flows, particularly as flows decelerate, because it can occur at low (, 0.1%) volume concentrations. This could have important implications for flow evolution and deposit geometries. Better quantitative constraints are needed on what controls flow capacity and competence, together with improved constraints on bed erosion and sediment resuspension. Recent advances in understanding dilute or mainly saline flows in submarine channels should be extended to explore how flow behavior changes as sediment concentrations increase. The petroleum industry requires predictive models of longer-term channel system behavior and resulting deposit architecture, and for these purposes it is important to distinguish between geomorphic and stratigraphic surfaces

show abstract

The response of turbidity currents to a canyon–fan transition: internal hydraulic jumps and depositional signatures

Cited by 134 publications

References 38 publications

Cyclic steps formed by turbidity currents

Cyclic steps formed by turbidity currents

Disconnected submarine lobes as a record of stepped slope evolution over multiple sea-level cycles

Key Future Directions For Research On Turbidity Currents and Their Deposits

Contact Info

Product

Resources

About