The Andøya Slide and the Andøya Canyon, north-eastern Norwegian–Greenland Sea

Based on GLORIA side-scan sonar imagery, echo sounder records, 3.5 kHz profiles, multichannel seismics and gravity cores the Andøya Slide and Andøya Canyon, north-eastern Norwegian–Greenland Sea were mapped and interpreted. The Andøya Slide covers an area of about 9700 km2 of which the slide scar area comprise ca. 3600 km2. The slide has a total run-out distance of about 190 km. Slope failure is inferred to have occurred during the Holocene because the slide scar has prominent relief on the present sea floor. The area of sediment removal is characterised by an irregular relief were relatively consolidated sediments are exposed at the sea floor. Little or no unconsolidated sediments overlies the slide deposits. Earthquake activity is inferred to have triggered the slide. A Holocene age of the Andøya Slide implies that three giant slides (the Storegga, Trænadjupet and Andøya Slides) have occurred along the continental slope of Norway during the last 10,000 years. A large canyon, the Andøya Canyon, is located immediately south of the Andøya Slide. On the upper slope, the canyon has been incised about 1000 m in the bedrock, and the maximum width at the bottom and between the canyon shoulders is 2 and 12 km, respectively. The Andøya Canyon represents the upper part of the Lofoten Basin Channel. Based on analogy with other deep-sea canyon/channel systems, the Andøya Canyon/Lofoten Basin Channel is possibly of pre-Quaternary age. Holocene sediments recovered from within the canyon, and draping the flanking channel deposits, indicate that the Andøya Canyon is not presently active and has probably not been active during the Holocene. During the Holocene, the canyon acted as a trap for sediments settling from the winnowing Norwegian Current.