Mass wasting on the submarine Lomonosov Ridge, central Arctic Ocean

A total of seven arcuate transverse troughs 5–6 km wide, 7–9 km long and 150–200 m deep are present on both sides of the crest of the central part of Lomonosov Ridge, Arctic Ocean. The troughs occur within a restricted ridge length of ca. 65 km. Trough morphology and disrupted, piecewise continuous sub-bottom reflections down to a common stratigraphic horizon below the troughs indicate lateral spread of progressively disintegrating sediment blocks above a glide plane. Lomonosov Ridge is aseismic, but the spatially restricted mass waste occurrences suggest sediment instability induced by earthquake loading. Another possibility is a pressure wave from a possible impact of an extraterrestrial object on Alpha Ridge about 500 km away. The slide event(s) is likely to be pre-late Pleistocene as sediment deposition within one of the slide scars appears continuous over the last c. 600 ka.