Morphodynamics of a field of crescent-shaped rippled scour depressions: Northern Monterey Bay, CA

Marine Geology
By: , and 

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Abstract

Despite the prevalence of rippled scour depression (RSD) on the world's continental shelves and their importance as nursery habitats for many commercially-important species, the processes responsible for their formation and geomorphic evolution are still not well understood. Most studies that focused on RSD evolution have been based on data acquired over multiple years to decades, and often during calmer summer months. Here, multiple geophysical seafloor mapping surveys of a field of RSD's off Santa Cruz, California, USA, were conducted over the course of two winters with distinctly different oceanographic forcing; these results were compared to time series oceanographic measurements made within the survey area, and put into the context of long-term trends from survey data collected during previous decades. Although the migration of these features across the seafloor occurs on decadal time scales, significant change was detected within a given year, depending on the wave climate and fluvial sediment input. RSDs shrank up to 16% or grew up to 28% in a span of a few months. Such change was predominantly the result of redistribution of fine-grained sediment input to the system by local rivers. Migration of the seafloor features appears to be the result of accumulation of fine-grained sediment at the boundary between the RSD and the surrounding fine-grained cap.

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Additional publication details

Publication type Article
Publication Subtype Journal Article
Title Morphodynamics of a field of crescent-shaped rippled scour depressions: Northern Monterey Bay, CA
Series title Marine Geology
DOI 10.1016/j.margeo.2018.10.006
Volume 407
Year Published 2019
Language English
Publisher Elsevier
Contributing office(s) Pacific Coastal and Marine Science Center
Description 16 p.
First page 44
Last page 59
Country United States
State California
Other Geospatial Northern Monterey Bay