Seabed morphology and sedimentary processes on high-gradient trough mouth fans offshore Troms, northern Norway

Abstract

9Trough mouth fans (TMF) situated at the mouths of formerly glaciated cross-shelf troughs are 10 important palaeoclimatic archives. Whereas the sedimentary processes of large, low-gradient 11TMFs have received considerable interest, little attention has been paid to the other end 12 member of this landform class, i.e. TMFs with higher slope gradients. Detailed swath-13 bathymetric data and seismic profiles from the continental margin offshore Troms, northern 14

Geomorphology and development of a high-latitude channel system: the INBIS channel case (NW Barents Sea, Arctic)

“…Similar V-shaped gullies on steep TMF slopes in both Arctic (e.g. Rydningen et al, 2015) and Antarctic (e.g. Vorren et al, 1998;Laberg & Vorren, 1995, 1996, 2000).…”

The Kongsfjorden Channel System offshore NW Svalbard: downslope sedimentary processes in a contour-current-dominated setting

“…[30,31,70,71]). They can be subdivided into low-gradient and high-gradient TMFs, respectively [60]. Based on Rydningen et al [60], low-gradient TMFs have surface inclinations of 0.5°-1.0°, whereas the surfaces of high-gradient TMFs typically have slope angles of 1°-15°.…”

“…Gully formation has probably mainly taken place during glaciations when grounded ice reached the mouth of the Kongsfjorden Trough. Various mechanisms may have led to their formation, including descending dense water masses rejected from brine formation, turbidity flows beyond the mouths of glacial troughs or retrogressive slope failure (compare with [8,19,43,48,60,71]). Sediment supply into the gully system may also have occurred during interglacials, due to winnowing of fine-grained material from the upper parts of the continental slope (compare, e.g.…”

“…Sediment supply into the gully system may also have occurred during interglacials, due to winnowing of fine-grained material from the upper parts of the continental slope (compare, e.g. with [2,60]). However, sediment flux has most probably been significantly lower compared to glacials.…”

“…[32]) and/or (3) debris flows transformed and disintegrated into turbidity flows (compare with, e.g. [9,60]). …”