Fascinating blog sounds like your really have some great data. I was wondering if i might pick your brains if you have time? I’m currently writing an essay and have chosen the possible comet impact theory as an exploitation for the demise of Clovis culture in N. America and the collapse of the laurentide ice sheet circa 12,900 cal BP. I’m focusing on the so called charred layer that has been proposed as evidence for this impact and was wondering if it has appeared in any of your cores at all?

Kind regards

Tim

Good questions, unfortunately until our new cores are processed some of the answers are not clear! Whilst we know that the region is very prone to large landslides, the reason why is still unclear, there are several theories, the first relates to methane clathrates dissociating from sediment under excess pore pressure and destabilising the slope, this is under investigation by a team at NOC and one of the previous mentors on this course, Eric Attias. We are also looking at the earthquake theory, as the ice melted the land re-adjusted and the rebound can occur as large earthquakes which often trigger landslides. The region is at the mouth if the North Sea Fn, and area of exceptionally high sediment delivery, and this may also contribute to the slides.

What we hope to find in the new core dataset is some indication of the climate changes happening at the time. There is a rough correlation between the end of the ice ages and the slides, but none of them beyond Storegga have been accurately dated. We have hopefully got a good record of the penultimate slide, the Tampen Slide, which is currently dated to 125 ka BP, and the previous 5 slides are believed to have occurred roughly once every 100 ka, though the dating on these slides is purely through geophysical interpretation of the units they have disturbed.

This work will take some time, but we would hope to have some preliminary results within the next year. As to methane clathrates, potentially they could contribute substantially to global warming. Methane is approximately 21 times more powerful as a greenhouse gas than carbon dioxide, as such any large release would cause warming. What we don’t know at the moment, is whether this happens directly as a result of the slides.

Interestingly, although Storegga is the largest slide in the Nordic seas, there are other vulnerable regions on the margin, including the Traenadjupet region, and the Voring Plateau, as this part of the margin hosts some of the most important and vulnerable global currents, we need to also understand how changes in the currents affect the sea floor. It is possible that these slides occur more regularly than we have previously thought, and that is part of the wider work being undertaken by the Landslide Tsunami Project.

I hope that helps a little, these results will be very interesting when they come out!