In:
Antarctic Science, Cambridge University Press (CUP), Vol. 15, No. 4 ( 2003-12), p. 537-546
Abstract:
Data from eight CTD casts and two one-year long current time series collected at 8 and 60 m above the seafloor of a sediment drift, off the Pacific Margin of the Antarctic Peninsula are presented, with special emphasis on bottom boundary layer dynamics and processes relevant to sediment settling and re-suspension. The water masses over the drift are characterized, including also a comparison with other measurements available from that region. The south-westward flow along the continental rise exhibits a strong topographic (bathymetric) control in the near-bottom current regime. A consistent mean flow deflection between an upper and lower current regime suggests that only the lower regime falls within a bottom (turbulent) Ekman layer. The bottom current regime is not energetic enough to maintain the coarse sediment fraction in suspension. The absence of evidence for a nepheloid layer justifies the assumption that most sediment was supplied to the margin during glacial periods. Two events, with peak velocities of up to 20 cm s −1 , are associated with barotropic eddies shown as negative (cyclonic) mean sea level anomalies detected by ERS/TOPEX satellite altimeters. These energetic bottom current pulses may give way to episodic sediment re-suspensions of the sortable (non-cohesive) part of the sediment, thus exerting a minor role in redistributing fine sediments through the mean flow regime.
Type of Medium:
Online Resource
ISSN:
0954-1020
,
1365-2079
DOI:
10.1017/S0954102003001652
Language:
English
Publisher:
Cambridge University Press (CUP)
Publication Date:
2003
detail.hit.zdb_id:
2104104-0
detail.hit.zdb_id:
1009128-2
SSG:
12
SSG:
13
SSG:
14
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