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The inherent instability of leveed seafloor channels
Author(s) -
Dorrell Robert M.,
Burns Alan D.,
McCaffrey William D.
Publication year - 2015
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1002/2015gl063809
Subject(s) - geology , aggradation , channel (broadcasting) , seafloor spreading , forcing (mathematics) , levee , instability , flow (mathematics) , avulsion , geomorphology , geophysics , climatology , fluvial , mechanics , computer science , geotechnical engineering , physics , computer network , structural basin
New analytical models demonstrate that under aggradational flow conditions, seafloor channel‐levee systems are inherently unstable; both channel area and stability necessarily decrease at long timescales. In time such systems must avulse purely through internal (autogenic) forcing. Although autogenic instabilities likely arise over long enough time for additional allogenic forcing to be expected, channel‐levee sensitivity to variations in flow character depends on the prior degree of system evolution. Recalibrated modern Amazon Fan avulsion timings are consistent with this model, challenging accepted interpretations of avulsion triggering.