Sediment concentrations, flow conditions, and downstream evolution of two turbidity currents, Monterey Canyon, USA

Deep-Sea Research Part I: Oceanographic Research Papers
By: , and 

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Abstract

The capacity of turbidity currents to carry sand and coarser sediment from shallow to deep regions in the submarine environment has attracted the attention of researchers from different disciplines. Yet not only are field measurements of oceanic turbidity currents a rare achievement, but also the data that have been collected consist mostly of velocity records with very limited or no suspended sediment concentration or grain size distribution data. This work focuses on two turbidity currents measured in Monterey Canyon in 2002 with emphasis on suspended sediment from unique samples collected within the body of these currents. It is shown that concentration and grain size of the suspended material, primarily controlled by the source of the gravity flows and their interaction with bed material, play a significant role in shaping the characteristics of the turbidity currents as they travel down the canyon. Before the flows reach their normal or quasi-steady state, which is defined by bed slope, bed roughness, and suspended grain size, they might pass through a preliminary adjustment stage where they are subject to capacity-driven deposition, and release heavy material in excess. Flows composed of fine (silt/clay) sediments tend to be thicker than those with sands. The measured velocity and concentration data confirm that flow patterns differ between the front and body of turbidity currents and that, even after reaching normal state, the flow regime can be radically disrupted by abrupt changes in canyon morphology.

Additional publication details

Publication type Article
Publication Subtype Journal Article
Title Sediment concentrations, flow conditions, and downstream evolution of two turbidity currents, Monterey Canyon, USA
Series title Deep-Sea Research Part I: Oceanographic Research Papers
DOI 10.1016/j.dsr.2014.04.001
Volume 89
Year Published 2014
Language English
Publisher Elsevier Science
Publisher location New York, NY
Contributing office(s) Pacific Coastal and Marine Science Center
Description 24 p.
First page 11
Last page 34
Online Only (Y/N) N
Additional Online Files (Y/N) N