Tide-supported gravity flows on the upper delta front, Fraser River delta, Canada

Korhan Ayranci; D. Gwyn Lintern; Philip R. Hill; Shahin E. Dashtgard

doi:10.1016/j.margeo.2012.09.007

Tide-supported gravity flows on the upper delta front, Fraser River delta, Canada

Korhan Ayranci^*, D. Gwyn Lintern, Philip R. Hill, Shahin E. Dashtgard

^*Corresponding author for this work

Research output: Contribution to journal › Article › peer-review

51 Scopus citations

Abstract

Three anomalous events (AEs) were recorded off the Fraser River, Canada during the freshet of 2008, and are ascribed to quasi-continuous gravity flows. These flows transport warm, low-salinity Fraser River waters to the upper delta front of the Fraser delta to at least 50. m water depth. All flows occurred during the freshet and spring ebbing tide, and were characterized by deposition of fine-grained sand and silt beds with likely high-water contents. These sediments were susceptible to resuspension by the subsequent flood-tide current, producing very high near bed suspended sediment concentrations (SSC) with enough excess density to generate hyper-concentrated flows. Our observations show that these episodic events result from the combination of high river discharge, high SSC, and strong tides, and therefore, are likely to occur on the delta fronts of other large tide-dominated and tide-influenced rivers. In shallow-water basins (< 50. m water depth), these tide-supported gravity flows can affect sediment deposition on both the delta front and prodelta.

Original language	English
Pages (from-to)	166-170
Number of pages	5
Journal	Marine Geology
Volume	326-328
DOIs	https://doi.org/10.1016/j.margeo.2012.09.007
State	Published - 1 Oct 2012
Externally published	Yes

Bibliographical note

Funding Information:
We kindly thank Nexen Inc. , Suncor Energy , Statoil Ltd. , and the Natural Sciences and Engineering Research Council (NSERC) of Canada for their financial support. We also thank the VENUS team at the University of Victoria for their contribution to this work. The VENUS cable observatory infrastructure was primarily funded by the Canada Foundation for Innovation (CFI) and the British Columbia Knowledge Development Fund . Operating support is provided by CFI , NSERC , Fisheries and Oceans Canada and Natural Resources Canada (Earth Sciences sector). This is ESS Contribution # 20120230.

Keywords

Deltas
Gravity flow
Hyperpycnal
Salinity
Turbidites
VENUS

ASJC Scopus subject areas

Oceanography
Geology
Geochemistry and Petrology

Access to Document

10.1016/j.margeo.2012.09.007

Cite this

@article{b0c87d7637884c209b9971d7d9ccb2de,

title = "Tide-supported gravity flows on the upper delta front, Fraser River delta, Canada",

abstract = "Three anomalous events (AEs) were recorded off the Fraser River, Canada during the freshet of 2008, and are ascribed to quasi-continuous gravity flows. These flows transport warm, low-salinity Fraser River waters to the upper delta front of the Fraser delta to at least 50. m water depth. All flows occurred during the freshet and spring ebbing tide, and were characterized by deposition of fine-grained sand and silt beds with likely high-water contents. These sediments were susceptible to resuspension by the subsequent flood-tide current, producing very high near bed suspended sediment concentrations (SSC) with enough excess density to generate hyper-concentrated flows. Our observations show that these episodic events result from the combination of high river discharge, high SSC, and strong tides, and therefore, are likely to occur on the delta fronts of other large tide-dominated and tide-influenced rivers. In shallow-water basins (< 50. m water depth), these tide-supported gravity flows can affect sediment deposition on both the delta front and prodelta.",

keywords = "Deltas, Gravity flow, Hyperpycnal, Salinity, Turbidites, VENUS",

author = "Korhan Ayranci and Lintern, \{D. Gwyn\} and Hill, \{Philip R.\} and Dashtgard, \{Shahin E.\}",

note = "Funding Information: We kindly thank Nexen Inc. , Suncor Energy , Statoil Ltd. , and the Natural Sciences and Engineering Research Council (NSERC) of Canada for their financial support. We also thank the VENUS team at the University of Victoria for their contribution to this work. The VENUS cable observatory infrastructure was primarily funded by the Canada Foundation for Innovation (CFI) and the British Columbia Knowledge Development Fund . Operating support is provided by CFI , NSERC , Fisheries and Oceans Canada and Natural Resources Canada (Earth Sciences sector). This is ESS Contribution \# 20120230.",

year = "2012",

month = oct,

day = "1",

doi = "10.1016/j.margeo.2012.09.007",

language = "English",

volume = "326-328",

pages = "166--170",

journal = "Marine Geology",

issn = "0025-3227",

publisher = "Elsevier B.V.",

}

TY - JOUR

T1 - Tide-supported gravity flows on the upper delta front, Fraser River delta, Canada

AU - Ayranci, Korhan

AU - Lintern, D. Gwyn

AU - Hill, Philip R.

AU - Dashtgard, Shahin E.

N1 - Funding Information: We kindly thank Nexen Inc. , Suncor Energy , Statoil Ltd. , and the Natural Sciences and Engineering Research Council (NSERC) of Canada for their financial support. We also thank the VENUS team at the University of Victoria for their contribution to this work. The VENUS cable observatory infrastructure was primarily funded by the Canada Foundation for Innovation (CFI) and the British Columbia Knowledge Development Fund . Operating support is provided by CFI , NSERC , Fisheries and Oceans Canada and Natural Resources Canada (Earth Sciences sector). This is ESS Contribution # 20120230.

PY - 2012/10/1

Y1 - 2012/10/1

N2 - Three anomalous events (AEs) were recorded off the Fraser River, Canada during the freshet of 2008, and are ascribed to quasi-continuous gravity flows. These flows transport warm, low-salinity Fraser River waters to the upper delta front of the Fraser delta to at least 50. m water depth. All flows occurred during the freshet and spring ebbing tide, and were characterized by deposition of fine-grained sand and silt beds with likely high-water contents. These sediments were susceptible to resuspension by the subsequent flood-tide current, producing very high near bed suspended sediment concentrations (SSC) with enough excess density to generate hyper-concentrated flows. Our observations show that these episodic events result from the combination of high river discharge, high SSC, and strong tides, and therefore, are likely to occur on the delta fronts of other large tide-dominated and tide-influenced rivers. In shallow-water basins (< 50. m water depth), these tide-supported gravity flows can affect sediment deposition on both the delta front and prodelta.

AB - Three anomalous events (AEs) were recorded off the Fraser River, Canada during the freshet of 2008, and are ascribed to quasi-continuous gravity flows. These flows transport warm, low-salinity Fraser River waters to the upper delta front of the Fraser delta to at least 50. m water depth. All flows occurred during the freshet and spring ebbing tide, and were characterized by deposition of fine-grained sand and silt beds with likely high-water contents. These sediments were susceptible to resuspension by the subsequent flood-tide current, producing very high near bed suspended sediment concentrations (SSC) with enough excess density to generate hyper-concentrated flows. Our observations show that these episodic events result from the combination of high river discharge, high SSC, and strong tides, and therefore, are likely to occur on the delta fronts of other large tide-dominated and tide-influenced rivers. In shallow-water basins (< 50. m water depth), these tide-supported gravity flows can affect sediment deposition on both the delta front and prodelta.

KW - Deltas

KW - Gravity flow

KW - Hyperpycnal

KW - Salinity

KW - Turbidites

KW - VENUS

UR - https://www.scopus.com/pages/publications/84868208070

U2 - 10.1016/j.margeo.2012.09.007

DO - 10.1016/j.margeo.2012.09.007

M3 - Article

AN - SCOPUS:84868208070

SN - 0025-3227

VL - 326-328

SP - 166

EP - 170

JO - Marine Geology

JF - Marine Geology

ER -

Tide-supported gravity flows on the upper delta front, Fraser River delta, Canada

Abstract

Bibliographical note

Keywords

ASJC Scopus subject areas

Access to Document

Fingerprint

Cite this