Geochemical characterization of resuspended sediment on the southeast slope of the Faeroe-Shetland Channel

Grain size, La/Yb and Th/Sc of settling particles in the western North Pacific: Evidence for lateral transport of small Asian loess

“…Since the grain size distribution of lithogenic par- ticles in this study ranged from 0.6 µm to 30 µm (Fig. 4), which is in the size range of the bulk settling particles (Bonnin et al, 2005), we can consider that all lithogenic particles were collected with the same trapping efficiency. Therefore the observed LLP/SLP ratios will not change, even if a correction is made for trapping efficiency.…”

“…In fact, Otosaka et al (2004) reported a very low trapping efficiency (0.38) at 1000 m at the same location. The grain size distribution of the bulk settling particles ranged from 0.6 µm to approximately 200 µm because the settling particles include particles with a large grain size (for example, foraminifera having carbonate testa) and particles with a small grain size (for example, lithogenic particles) (Bonnin et al, 2005). If trapping efficiency depends on the grain size of particles, there is difference in trapping efficiency as between carbonate and lithogenic particles.…”

“…Otosaka et al (2004) studied the transport process of lithogenic particles in the western North Pacific using only chemical components, and they did not measured the grain size distribution, which is one of the factors that control the behavior of particles in the ocean (Rea and Hovan, 1995). Although it is important to measure the grain size distribution in order to understand the transport process, there have been very few investigations of the grain size of settling particles (e.g., Ratmeyer et al, 1999;Li et al, 2004;Bonnin et al, 2005).…”

Burst resuspension of seabed material at the foot of the continental slope in the Rockall Channel

“…Strong slope currents van Weering, 1998, Durrieu de Madron et al, 1999) or internal waves impinging on the slope have been proposed as potential mechanisms for sediment resuspension and transport on the slope (Thorpe and White, 1988;Gardner, 1989;van Raaphorst et al, 2001;Cacchione et al, 2002). Results from oceanographic surveys carried out in the Faeroe-Shetland Channel in the framework of PROCS (Processes at the Continental Slope) showed that internal solibores caused abrupt changes in the current regime and in the suspended particle load near the bottom and facilitated sediment transport up the slope (Bonnin et al, 2002(Bonnin et al, , 2005. Such shortterm processes have a profound effect on the sedimentology and geochemistry of surface sediments (Bonnin and van Raaphorst, 2004) and are also thought to strongly influence the distribution of large epibenthic communities such as corals and sponges (Klitgaard et al, 1997).…”

Mapping turbidity layers using seismic oceanography methods

“…However, the data on sediment traps from PROCS were published in (van Raaphorst et al, 2001 and references therein). Median grain size was found to decrease with depth over the slope, from 274 µm at 649 m to 158 µm at 801 m. A later study (Bonnin et al, 2005) found the median grains size of the surface sediment to be approximately 150 µm, and to remain at this value at depths greater than 600 m. Approximately 70 % of sediment fell within the size range 63-250 µm (Bonnin et al, 2005 their Fig. 7).…”