Rapidly-migrating and internally-generated knickpoints can control submarine channel evolution
Type | Article | ||||||||||||||||
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Date | 2020-06 | ||||||||||||||||
Language | English | ||||||||||||||||
Author(s) | Heijnen Maarten S.1, 2, Clare Michael A.1, Cartigny Matthieu J. B.3, 4, Talling Peter J.3, 4, Hage Sophie2, 8, Lintern D. Gwyn5, Stacey Cooper5, Parsons Daniel R.6, Simmons Stephen M.6, Chen Ye6, Sumner Esther J.2, Dix Justin K.2, Clarke John E. Hughes7 | ||||||||||||||||
Affiliation(s) | 1 : Natl Oceanog Ctr, European Way, Southampton SO14 3ZH, Hants, England. 2 : Univ Southampton, Natl Oceanog Ctr, Ocean & Earth Sci, European Way, Southampton SO14 3ZH, Hants, England. 3 : Univ Durham, Dept Geog, South Rd, Durham DH1 3LE, England. 4 : Univ Durham, Dept Earth Sci, South Rd, Durham DH1 3LE, England. 5 : Geol Survey Canada, Nat Resources Canada, Box 6000,9860 West Saanich Rd, Sidney, BC, Canada. 6 : Univ Hull, Energy & Environm Inst, Cottingham Rd, Kingston Upon Hull HU6 7RX, N Humberside, England. 7 : Univ New Hampshire, Ctr Coastal & Ocean Mapping, Earth Sci, 24 Colovos Rd, Durham, NC USA. 8 : Univ Calgary, Dept Geosci, Calgary, AB T2N 1N4, Canada. |
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Source | Nature Communications (2041-1723) (Nature Research), 2020-06 , Vol. 11 , N. 1 , P. 3129 (15p.) | ||||||||||||||||
DOI | 10.1038/s41467-020-16861-x | ||||||||||||||||
WOS© Times Cited | 38 | ||||||||||||||||
Keyword(s) | Geomorphology, Sedimentology | ||||||||||||||||
Abstract | Submarine channels are the primary conduits for terrestrial sediment, organic carbon, and pollutant transport to the deep sea. Submarine channels are far more difficult to monitor than rivers, and thus less well understood. Here we present 9 years of time-lapse mapping of an active submarine channel along its full length in Bute Inlet, Canada. Past studies suggested that meander-bend migration, levee-deposition, or migration of (supercritical-flow) bedforms controls the evolution of submarine channels. We show for the first time how rapid (100-450m/year) upstream migration of 5-to-30 m high knickpoints can control submarine channel evolution. Knickpoint migration-related changes include deep (>25m) erosion, and lateral migration of the channel. Knickpoints in rivers are created by external factors, such as tectonics, or base-level change. However, the knickpoints in Bute Inlet appear internally generated. Similar knickpoints are found in several submarine channels worldwide, and are thus globally important for how channels operate. The authors analyse 9 years of time-lapse surveys in Bute Inlet, British Columbia (CA), to show how an active submarine channel evolves. They show how channel evolution is controlled by fast upstream-migration of steep knickpoints, which are similar to waterfalls in rivers. |
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