Skip to main content

Research Repository

Advanced Search

Near‐Bed Structure of Sediment Gravity Flows Measured by Motion‐Sensing “Boulder‐Like” Benthic Event Detectors (BEDs) in Monterey Canyon

Gwiazda, R.; Paull, C.K.; Kieft, B.; Klimov, D.; Herlien, R.; Lundsten, E.; McCann, M.; Cartigny, Matthieu J.; Hamilton, A.; Xu, J.; Maier, Katherine L.; Parsons, D.R.; Talling, Peter J.

Near‐Bed Structure of Sediment Gravity Flows Measured by Motion‐Sensing “Boulder‐Like” Benthic Event Detectors (BEDs) in Monterey Canyon Thumbnail


Authors

R. Gwiazda

C.K. Paull

B. Kieft

D. Klimov

R. Herlien

E. Lundsten

M. McCann

A. Hamilton

J. Xu

Katherine L. Maier

D.R. Parsons



Abstract

The near-bed section of submarine gravity flows travels at the highest and most destructive speeds making direct measurements of this region of the flow difficult. Here results are presented from “boulder-like” Benthic Event Detectors (BEDs) that measured their own rotation, depth and temperature while carried within the near-bed region of gravity flows. BEDs were deployed in Monterey Canyon from 200 to 500 m water depth for 18 months (2016–2017) during the Coordinated Canyon Experiment. BEDs moved in 10 out of 14 gravity flows that transited the upper canyon. BEDs moved within the body of the flow because the initial velocities of the BEDs were 66 ± 16% (1 SD) of the flow transit velocities. BEDs rotated freely during most of their first moves and gained depth faster than in later moves, when their motion was more random and wobblier. The differences in BED motions between first and later moves suggest BEDs moved at different depths within the flow. The inferred near-bed flow structure is strongly stratified with a fast, less-dense layer moving above a slower and denser layer. Coherent changes between pressure and acceleration indicate that BEDs rode a crescent shaped bedform (CSB) morphology that persisted throughout flow events. The variability in BED speeds while riding the CSB morphology indicates a fluid-like nature of the near-bed layer. BED motions ended after being caught in the trough of a CSB. Based on recorded temperature decay rates after flow events, the thickness of redeposited sediment is 2–3 m.

Citation

Gwiazda, R., Paull, C., Kieft, B., Klimov, D., Herlien, R., Lundsten, E., …Talling, P. J. (2022). Near‐Bed Structure of Sediment Gravity Flows Measured by Motion‐Sensing “Boulder‐Like” Benthic Event Detectors (BEDs) in Monterey Canyon. Journal of Geophysical Research: Earth Surface, 127(2), https://doi.org/10.1029/2021jf006437

Journal Article Type Article
Acceptance Date Jan 21, 2022
Online Publication Date Feb 8, 2022
Publication Date 2022
Deposit Date May 16, 2022
Publicly Available Date May 16, 2022
Journal Journal of geophysical research. Earth surface.
Print ISSN 2169-9011
Electronic ISSN 2169-9011
Publisher American Geophysical Union
Peer Reviewed Peer Reviewed
Volume 127
Issue 2
DOI https://doi.org/10.1029/2021jf006437

Files

Published Journal Article (4.6 Mb)
PDF

Publisher Licence URL
http://creativecommons.org/licenses/by/4.0/

Copyright Statement
This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.





You might also like



Downloadable Citations