Recent slope mobilizations in the Storegga Slide area

• Main Authors: Berndt, Christian, Crutchley, Gareth, Krastel, Sebastian, Karstens, Jens, Dumke, Ines, Dünnbier, Karolin
• Format: Conference Object
• Language: unknown
• Published: 2012
• Subjects: Norway; Nyegga; Storegga; Iceland; North Atlantic
• Online Access: https://oceanrep.geomar.de/id/eprint/42742/

With ~3500 km3 of mobilized material the Storegga Slide off mid-Norway is one of the largest known sub-marine slope failures. It occurred approximately 8150 years ago and there is strong evidence suggesting that the slide caused a large tsunami that propagated through the North Atlantic and affected the coasts of Norway, Iceland and the U.K. In the Nyegga area along the northern side wall of the slide numerous shallow faults exist. These faults detach within the top 100 m below the sea floor at various stratigraphic levels below, at, and above the main slide plain of the Storegga Slide. Previous studies proposed that these faults are evidence for partial slope movements during the Storegga Slide event indicating that the adjacent slopes were deformed due to the stress variations caused by the Storegga Slide. New high-resolution Parasound data that we have collected in May 2012 onboard RV Meteor show offsets of reflectors that are buried less than 3 m below the sea floor. Assuming that the sedimentation rates derived from a near-by Marion Dufresne sediment core, can be extrapolated to the study area, these reflector offsets suggest that the faults are younger than the Storegga Slide. Given a several million year-long history of repeated slope failures in the area it is important to obtain more precise dates for the activity of the faults in order to assess if these faults can be used as an indicator for future slope failures in the area or if they are the result of small-scale adjustments of the head wall topography in the wake of the Storegga Slide.