Seabed II: High-resolution Acoustic Seabed Surveys of the Deep Ocean

Hutchins, R. W.; Dodds, J.; Fader, G B J

doi:10.1007/978-94-011-7358-2_6

Cited by 4 publications

(1 citation statement)

References 8 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Various acoustic systems have been employed to collect data in the area, including SeaMARC I (Kosalos & Chayes, 1983) and SeaMOR I1 (Hutchins et al, 1985;Dodds & Fader, 1987) mapping systems, as well as conventional 3.5 kHz, Huntec 'deep-tow' boomer (Hutchins et al, 1976) and NSRF 'deep tow' sparker (Bidgood, 1974) systems. Twenty cores were obtained by standard large and narrow diameter piston and gravity coring techniques.…”

Section: Methodsmentioning

confidence: 99%

Late Quaternary sediment, sediment mass flow processes and slope stability on the Scotian Slope, Canada

Mosher

Moran²,

Hiscott

1994

Sedimentology

View full text Add to dashboard Cite

The study area, just to the west of the Verrill Canyon on the Scotian Slope, eastern Canada, exhibits both large and small scale sediment mass movement features. Study of high resolution seismic reflection and sidescan sonar data shows that a large portion (approximately 70%) of the near surface sediment (<20 m) in the area has undergone erosion, rotational slumping and internal deformation. Remoulded sediment observed in physical properties profiles of piston cores and sediment deformation structures are further evidence of slumping. Small scale mass flow events are recorded by abundant turbidites and debris flow deposits noted in piston cores. Sediment physical properties are highly dependent on sediment type (lithofacies). Frequent facies changes, both temporally and spatially, make correlation between cores difficult. Although the small scale mass movement events correlate with glacial recession on the continental shelf and lower relative sea levels, the triggering mechanisms for the large scale events are less obvious. Slope stability analyses indicate that, at present, the seabed is stable. The most plausible explanation for large scale slope failures in this region are ground accelerations related to earthquake shock. Our analyses demonstrate that it is unlikely that large magnitude, distant earthquakes, such as those previously proposed in the Laurentian Slope Seismic Zone (LSP) model, could initiate failure of sediment in the study region. Our data support the interpretation that more frequent, lower magnitude earthquakes, closer to the study region, as previously proposed in the Eastern Slope Experimental Source Zone (ESX) model, are the likely causes of large scale slope failures. Furthermore, excess pore pressures resulting from shallow gas and/or high sedimentation rates during deglaciation contribute to slope failure.

show abstract