Submarine slope stability on high-latitude glaciated Svalbard–Barents Sea margin

Slope stability is evaluated at two locations on high latitude, deep sea fans along the Svalbard–Barents Sea margin, based on available samples and using an “infinite slope” analysis. The stability evaluation uses the Mohr–Coulomb failure criterion, and a semi-analytical approach based on Gibson's formulation for determining the excess pore pressure build-up due to sedimentation. The main results are presented in the form of contour plots of slope safety factors in a diagram with axes of time and thickness of deposit. The results show that during rapid sedimentation, which mostly takes place during periods of maximum glaciation with the ice front located along the shelf edge, slope failure will occur with a frequency varying between 95 and 170 years. Only part of the upper sedimented layer will be mobilised (10–30 m), while the remaining thickness (40–70 m) will remain at the initial sedimentation site. These results may explain why the continental slope is characterised by relatively uniform sediment thickness from upper to lower slope.