Submarine slides from the walls of Smeerenburgfjorden, NW Svalbard

Abstract

The steep slopes of glacially eroded fjord walls are potential sites for slope failure and mass wasting (Syvitski et al. 1987). Slides of sedimentary material are relatively common but require that sediment is present on fjord sides, often deposited from glaciers before and during their retreat through fjord systems. This debris then fails, producing slides that run out onto fjord floors and leave scars on fjord side-walls. On the steep side-walls and floor of Smeerenburgfjorden, a 25 km long fjord in NW Spitsbergen, Svalbard, more than 30 slide scars and associated depositional zones are observed on both sides of the fjord (Fig. 1) (Ottesen & Dowdeswell 2009). The slide headwalls are usually located on slopes greater than 15°. The depositional zones of the slides are usually (but not always) blocky, and the scar surfaces are also relatively rough (Fig. 1a–d). Many of the slides appear to be composites of several individual failure events (Fig. 1b, c), whereas a few record only single failures (Fig. 1d). Examples of composite failures include at least four events in Figure 1b and three or more in …