Braiding of submarine channels controlled by aspect ratio similar to rivers

Foreman, Brady Z.; Lai, Shiow-Suey; Komatsu, Yuhei; Paola, Chris

doi:10.1038/ngeo2505

Cited by 22 publications

(34 citation statements)

References 25 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Reduced gravity -due to lower planetary mass -on Mars requires deeper flows for equivalent basal stresses, and enhances sediment suspension and thus also overbank sedimentation rates 9 . This raises the possibility that the mechanism postulated by Foreman et al 4 for the restriction of braiding in the deep-sea may apply more broadly to other planetary bodies characterised by reduced gravity and salinity. In combination, reduced gravity and salt-induced flocculation are proposed to encourage rapid accretion of cohesive banks, maintenance of channel width, and stabilisation of meandering planforms 9 .…”

Section: News and Viewsmentioning

confidence: 99%

“…Foreman et al 4 demonstrate that braided channels on the sea floor can form in the same way that they do on land, but suggest that the conditions for braiding are rarely met in submarine environments. Intriguingly, the work implies that true braided systems may be a far rarer channel pattern than previously thought: as observed, braided channels may be largely absent in submarine systems on Earth, and on bodies elsewhere in the Solar System.…”

Section: News and Viewsmentioning

confidence: 99%

“…Foreman et al 4 conducted experiments in two laboratories to examine whether gravity currents can form braided channels. In each case they utilized broad subaqueous sheets (width to depth ratios of 350:1 to 1000:1) of denser saline fluid mixed with sediment, over initially flat beds of lowdensity non-cohesive sediment consisting of plastic particles or crushed walnut shells.…”

mentioning

confidence: 99%

“…They note that the reduced density difference between the particulate-water mixture and the surrounding seawater, which drives submarine gravity flows, requires that flows must be deeper relative to rivers for the same basal stress. Foreman et al 4 use experiments to show that given similar conditions to rivers, submarine flows are capable of producing braided channels, however their rarity in nature suggests that submarine channel processes are very different from their terrestrial cousins. In addition, the suspension-dominated flows GEOMORPHOLOGY Undersea river patterns Braided channels are rare on ocean floors, but abundant on land.…”

mentioning

confidence: 99%

See 3 more Smart Citations

Undersea river patterns

Peakall

2015

Nature Geosci

View full text Add to dashboard Cite

Section: News and Viewsmentioning

confidence: 99%

Section: News and Viewsmentioning

confidence: 99%

mentioning

confidence: 99%

mentioning

confidence: 99%

See 2 more Smart Citations

Undersea river patterns

Peakall

2015

Nature Geosci

View full text Add to dashboard Cite

“…The experiments by Foreman et al . () indicated that submarine braided channels form under high flow width to depth ratios (i.e. >100), similar to fluvial channels (Parker, ).…”

Section: Introductionmentioning

confidence: 97%

Geometry and dynamics of braided channels and bars under experimental density currents

et al. 2018

Self Cite

View full text Add to dashboard Cite

Submarine channels convey turbidity currents, the primary means for distributing sand and coarser sediments to the deep ocean. In some cases, submarine channels have been shown to braid, in a similar way to rivers. Yet the strength of the analogy between the subaerial and submarine braided channels is incompletely understood. Six experiments with subaqueous density currents and two experiments with subaerial rivers were conducted to quantify: (i) submarine channel kinematics; and (ii) the responses of channel and bar geometry to subaerial versus submarine basin conditions, inlet conditions and the ratio of ‘flow to sediment’ discharge (Qw/Qs). For a range of Qw/Qs values spanning a factor of 2·7, subaqueous braided channels consistently developed, were deeper upstream compared to downstream, and alternated with zones of sheet flow downstream. Topographic analyses included spatial statistics and mapping bars and channels using a reduced‐complexity flow model. The ratio of the estimated depth‐slope product for the submarine channels versus the subaerial channels was greater than unity, consistent with theoretical predictions, but with downstream variations ranging over a factor of 10. For the same inlet geometry and Qw/Qs, a subaqueous experiment produced deeper, steeper channels with fewer channel threads than its subaerial counterpart. For the subaqueous cases, neither slope, nor braiding index, nor bar aspect ratio varied consistently with Qw/Qs. For the subaqueous channels, the timescale for avulsion was double the time to migrate one channel width, and one‐third the time to aggrade one channel depth. The experiments inform a new stratigraphic model for submarine braided channels, wherein sand bodies are more laterally connected and less vertically persistent than those formed by submarine meandering channels.

show abstract

An experimental approach to submarine canyon evolution

Lai

Gerber

Amblàs

2016

Geophysical Research Letters

Self Cite

View full text Add to dashboard Cite

We present results from a sandbox experiment designed to investigate how sediment gravity flows form and shape submarine canyons. In the experiment, unconfined saline gravity flows were released onto an inclined sand bed bounded on the downstream end by a movable floor that was used to increase relief during the experiment. In areas unaffected by the flows, we observed featureless, angle‐of‐repose submarine slopes formed by retrogressive breaching processes. In contrast, areas influenced by gravity flows cascading across the shelf break were deeply incised by submarine canyons with well‐developed channel networks. Normalized canyon long profiles extracted from successive high‐resolution digital elevation models collapse to a single profile when referenced to the migrating shelf‐slope break, indicating self‐similar growth in the relief defined by the canyon and intercanyon profiles. Although our experimental approach is simple, the resulting canyon morphology and behavior appear similar in several important respects to that observed in the field.

show abstract

Braiding of submarine channels controlled by aspect ratio similar to rivers

Cited by 22 publications

References 25 publications

Undersea river patterns

Undersea river patterns

Geometry and dynamics of braided channels and bars under experimental density currents

An experimental approach to submarine canyon evolution

Contact Info

Product

Resources

About