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[1] A fluorescent dye tracer was injected into the pycnocline on the Oregon shelf at a depth of 9–10 m. It spread rapidly cross-shelf as two distinct layers, one above the other in the water column, split by interleaving dye-free water. The vertical scale of these layers, and associated density steps, was 1–2 m, and the horizontal extent of interleaving(More)
[1] Hydrographic observations made with an undulating vehicle carrying a CTD and concurrent shipboard ADCP velocity observations over a 12-day period are combined to investigate vertical mixing and cross-frontal fluxes on the Northern Flank of Georges Bank. The CTD density time series is analyzed to detect the presence of vertical overturns, the statistics(More)
[1] Observations, from the Oregon continental shelf, describe the slumping of a coastal upwelling front in response to a reversal of winds from upwellingto downwellingfavorable. Initially, the front outcropped in a surface mixed layer of depth 10–20 m with a pronounced cross-shelf density gradient. Following wind reversal, both the unbalanced cross-shelf(More)
In contrast to generally sparse biological communities in open-ocean settings, seamounts and ridges are perceived as areas of elevated productivity and biodiversity capable of supporting commercial fisheries. We investigated the origin of this apparent biological enhancement over a segment of the North Mid-Atlantic Ridge (MAR) using sonar, corers, trawls,(More)
[1] During March–April 1999, 2 weeks of undulating CTD and shipboard acoustic Doppler current profiler surveys revealed the variability of the intense internal tide on the northern edge of Georges Bank. The nature of the internal tide was modulated by episodic surface intrusions of cool, fresh Scotian Shelf Water (SSW), stratifying the otherwise vertically(More)
Scallop dredging grounds in the Firth of Lorn, western Scotland, are juxtaposed with rocky reef habitats raising concerns that reef communities may be impacted by sediment disturbed by nearby scallop dredging. A particle-tracking model of sediment transport and settling is applied at two scales. In the near-field, a suspension of typical(More)
Using underwater gliders we have identified canyon driven upwelling across the Celtic Sea shelf-break, in the vicinity of Whittard Canyon. The presence of this upwelling appears to be tied to the direction and strength of the local slope current, which is in itself highly variable. During typical summer time equatorward flow, an unbalanced pressure gradient(More)
Verena Häussermann, Carolina S. Gutstein, Michael Bedington, David Cassis, Carlos Olavarria, Andrew C. Dale, Ana M. Valenzuela-Toro, Maria Jose Perez-Alvarez, Hector H. Sepúlveda, Kaitlin M. McConnell, Fanny E. Horwitz and Günter Försterra 1 Facultad de Ciencias Naturales, Escuela de Ciencias del Mar, Pontificia Universidad Católica de Valparaı́so,(More)
While large mass mortality events (MMEs) are well known for toothed whales, they have been rare in baleen whales due to their less gregarious behaviour. Although in most cases the cause of mortality has not been conclusively identified, some baleen whale mortality events have been linked to bio-oceanographic conditions, such as harmful algal blooms (HABs).(More)