Recurrent Pleistocene mega-failures on the SW Barents Sea margin

• Published in: Earth and planetary science letters Vol. 258; no. 3; pp. 605 - 618
• Main Authors: Hjelstuen, Berit Oline, Eldholm, Olav, Faleide, Jan Inge
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 30-06-2007
• Subjects: Barents Sea margin; glaciations; instabilities; trigger; PNE, Barents Sea; ANE, Norwegian Sea, Voering Plateau, Storegga Slide; glaciations; trigger; instabilities; slide; Barents Sea margin
• ISSN: 0012-821X; 1385-013X
• DOI: 10.1016/j.epsl.2007.04.025

Submarine slides have been instrumental in shaping the Late Neogene NE Atlantic continental margin. We document a margin setting north of 70°N capable of generating recurrent huge Pleistocene mass-movements. The 1.0–0.2 Ma old Bjørnøya Fan Slide Complex includes three buried mega-slides, which have left scars containing up to 500 m-thick debris units. The two largest slides may have had a retrogressive development, cover areas of the order of ∼
120
×
10
3 km
2, and involved ∼
25
×
10
3 km
3 of sediments. Thus, the failures involved an order of magnitude more sediment than the Storegga Slide, the world's largest exposed slide. The mega-slides occurred during the Northern Hemisphere Glaciations, characterized by greatly enhanced deposition rates leading to the construction of the 3-km-thick Bjørnøya Trough Mouth Fan that progressively loaded a softer Miocene–Oligocene substratum. This setting induced excess pore pressure and sediment instability, conditions favorable for sliding. External trigger mechanisms, such as earthquakes, may have facilitated the mass-wasting process.