Relative timing of the Storegga submarine slide, methane release, and climate change during the 8.2 ka cold event

This paper highlights the similarity in the timing between the 8.2 ka cold event across the North Atlantic region and one of the world’s largest underwater slides, the Storegga submarine landslide that took place on the continental slope west of Norway. We argue on the basis of a reinterpretation of the age of tsunami deposits that date the slide, as well as published ages of sediment directly resting upon the slide surface, that the slide occurred between 8100 and 8200 cal. yr, near the end of the 8.2 ka cold event. Because sediment exposed at the base of the slide contained less methane-gas-hydrate c. 8200 years ago than exists today and because Greenland ice cores do not show an increase in methane at the time of the slide, it is argued here that the slide did not release significant volumes of methane to the atmosphere and did not contribute to any change in temperature during or after the 8.2 ka cold event.