| Title | The stability of sublittoral, fine-grained sediments in a subarctic estuary |
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| Author | Amos, C L; Sutherland, T F; Zevenhuizen, J |
| Source | Sedimentology vol. 43, issue 1, 1996 p. 1-19, https://doi.org/10.1111/j.1365-3091.1996.tb01455.x |
| Year | 1996 |
| Alt Series | Geological Survey of Canada, Contribution Series 38194 |
| Publisher | Wiley-Blackwell |
| Document | serial |
| Lang. | English |
| Media | paper; on-line; digital |
| File format | html; pdf |
| Program | Regional Ocean Disposal Advisory Committee (RODAC) |
| Released | 1996 02 01 |
| Abstract | The erodibility of natural estuarine sediments was measured in sit along a longitudinal transect of Manitounuk Sound, Hudson Bay, using the benthic flume Sea Carousel. Sedimentation processes along the
transect varied from continuous, rapid, post?glacial sedimentation in the inner Sound, to glacial outcrops and seabed reworking of the outer Sound. The grain size and physical bulk properties reflect changes in depositional environment and correlate
with sediment erosion threshold stress (Tc), erosion rate (E), erosion type and still?water mass settling rate. There was a steady increase in ?c (0·8-2·0 Pa) with distance down the Sound in parallel with the decreasing sedimentation rate
(0·003-0·001 m yr-1) and increasing sediment bulk density (1650-2010 kg m-3). The near-surface friction coefficient varied up to 68° in proportion to the clay content of post-glacial material. Glacial sediments were characterized by variable results
and generally higher friction coefficients. Seabed erosion in Sea Carousel began with surface creep of loose aggregates, pellets and organic debris. This was followed by Type I bed erosion at rates that varied between 0·0002 and 0·0032 kg m-2 s-1
(mean 0·0015). Type I peak erosion rate was inversely related to applied bed shear stress (To). Type II erosion succeeded Type I, often after a broad transitional period. Simulations of suspended sediment concentration in Sea Carousel were made using
four commonly used erosion (E) algorithms. The best results were obtained using Krone's dimensionless ratio relationship: E=M(To/Tc-1). Simulations were highly sensitive to the definition of erosion threshold with sediment depth [Tc(z)]. Small errors
in definition of Tc(z) caused large errors in the prediction of suspended sediment concentration which far exceeded differences between the methods tested. |
| GEOSCAN ID | 204500 |
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