Ocean warming and gas hydrate stability on the mid-Norwegian margin at the Storegga Slide

Landslide tsunami hazard in the Indonesian Sunda Arc

“…This reduces the effective shear strength and leads to instability. Elevated pore pressure can moreover result from melting of gas hydrates, as suspected for landslides in the North Atlantic (Sultan et al, 2004;Mienert et al, 2005), but also off Indonesia evidences for gas hydrates have been found (Kopp, 2002). Another important cause is steepening of the slope.…”

Geological Hazards

“…The slide runs from the shallow depths of the shelf of Norway to the abyssal plain with a slope angle of 0.6°; major areas of the slide have an inclination <0.4° (Kvalstad et al, 2002). The genesis of the Storegga Slide is debated extensively and consensus about the mechanism for its formation has not emerged so far (Bugge et al, 1987;Berndt et al, 2002;Maslin et al, 2004;Sultan et al, 2004;Mienert et al, 2005;Kvalstad et al, 2002Kvalstad et al, , 2005Bryn et al, 2005). In general, excess pore pressure is considered the main causative mechanism for the genesis of the slide; however, the interpretation for the generation of excess pore pressure differs significantly.…”

Fangliao Slide — a large slope failure in the upper Kaoping Slope off southwest Taiwan

“…The preconditioning factors of slope failure are associated with high environmental stresses (e.g., earthquakes, folds and submarine canyon fan systems) (Hampton et al 1996) and overpressure in sedimentary layers due to rapid sedimentation and gas generation (Micallef et al 2009;Urlaub et al 2015;Cukur et al 2016). Thus, gas hydrate dissociation could play an important role on generating slope failures (McIver 1982;Mienert et al 2002;Horozal et al 2017), as was hypothesized in the case of the Storegga Slide off Norway (Bunz et al 2003;Berndt et al 2005;Mienert et al 2005;Brown et al 2006;Micallef et al 2009), the Cape Fear Slide off SE U. S. (Popenoe et al 1993;Schmuck and Paull 1993), the Blake Ridge Collapse off SE U. S. (Booth et al 1994;Dillon et al 1998), the Humboldt Slide off California U. S. (Gardner et al 1999;Yun et al 1999), and the Gulf of Cadiz slides off SW Spain (Baraza et al 1999). In the Storegga Slide, the area of gas hydrate dissociation is near the headwall of the slide and numerous fluid escape features were observed in the vicinity of the northern sidewall.…”

“…In the Storegga Slide, the area of gas hydrate dissociation is near the headwall of the slide and numerous fluid escape features were observed in the vicinity of the northern sidewall. It suggests that the Storegga Slide is closely related to gas hydrate dissociation (Berndt et al 2005;Mienert et al 2005). However, the morphology of Storegga Slide shows a retrogressive slide mechanism (Kvalstad et al 2005).…”