Radiocarbon dating of sediment cores from throughout the slide scar indicates that the Storegga Slide occurred around 8150 years before present (BP) 8. The failure of the central slide segment involved ~500 to 800 km³ and is considered the main contributor to tsunami generation 7. Based on seismically constrained pre-slide seafloor reconstructions, the first phase of the Storegga Slide mobilized ~1300 to 1600 km³, contributing 50% of the total slide volume, while lateral spreading and minor secondary slope failures added up to ~600 to 900 km³. Finally, the central slide segment failed and incised several hundred meters deep into the substrate 4, 6. ![]() During the second phase, remaining sediments were affected by lateral spreading along a well-defined glide plane as well as some minor, local slope failures 6. The first phase initiated more than 100 km downslope from the headwall and developed retrogressively upslope, removing up to 50 m of poorly consolidated, glacial sediments from the northern half of the slide scar, which transformed into debris flows and turbidity currents and were deposited hundreds of kilometers away in the Norway Basin 4, 5, 6. Previous analyses concluded that the Storegga Slide developed in multiple phases. With an estimated volume of 2400 to 3200 km³, the Storegga Slide is the largest known continental margin slope failure, stretching approximately 300 km along the mid-Norwegian continental shelf-break and extending over 800 km into the Norway Basin 4 (Fig. ![]() Morphological analyses of the continental margins of the North Atlantic have revealed dozens of late-Quaternary slide scars associated with slope failures of even greater dimensions 2, 3. ![]() ![]() The 1929 Grand Banks earthquake triggered the most recent large-scale landslide on open continental slopes, incorporating 200 km 3 of seafloor sediments, which caused a tsunami with run-up heights of up to 13 m on the Newfoundland coast 1.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |