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Transition of a Hyperpycnal Flow Into a Saline Turbidity Current Due to Differential Diffusivities
Author(s) -
Zhao Liang,
Ouillon Raphael,
Vowinckel Bernhard,
Meiburg Eckart,
Kneller Benjamin,
He Zhiguo
Publication year - 2018
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 - 10.1029/2018gl080150
Subject(s) - turbidity current , entrainment (biomusicology) , turbidity , sediment , turbulence , geology , transition zone , diffusion , turbulent diffusion , soil science , geomorphology , hydrology (agriculture) , mechanics , oceanography , geotechnical engineering , geophysics , physics , thermodynamics , sedimentary depositional environment , structural basin , rhythm , acoustics
We provide a new perspective on the transition of hyperpycnal flows into saline turbidity currents, which permits longer runout lengths than might be otherwise expected. This mechanism relies on the differential turbulent diffusion of salt and sediment, and in contrast to ambient saltwater entrainment it enables the salinification of the freshwater current without diluting the sediment concentration field by a corresponding amount. The freshness‐to‐sediment ratio is introduced in order to quantify the transition process. The results of high‐resolution simulations provide estimates for the transition distance of hyperpycnal model flows into saline turbidity currents.