Does Retrogression Always Account for the Large Volume of Submarine Megaslides? Evidence to the Contrary From the Tampen Slide, Offshore Norway
| Autor: | Felix Gross, Christian Berndt, Benjamin Bellwald, Sverre Planke, Reidun Myklebust, Aaron Micallef, Peter J. Talling, Rachel S. Barrett, Sebastian Krastel |
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| Rok vydání: | 2021 |
| Předmět: |
010504 meteorology & atmospheric sciences
010502 geochemistry & geophysics Earthquakes -- Norway 01 natural sciences Tsunamis -- Research Debris flow Head (geology) Glide plane Geochemistry and Petrology Passive margin Tsunamis -- Norway Submarine geology -- Research Earth and Planetary Sciences (miscellaneous) 14. Life underwater 0105 earth and related environmental sciences geography geography.geographical_feature_category Submarine topography -- Norway Volcanic eruptions -- Norway Landslide Landslides -- Risk assessment Geophysics 13. Climate action Space and Planetary Science Submarine pipeline Landslides -- Norway Oceanic basin Geology Seismology Submarine landslide |
| Zdroj: | Journal of Geophysical Research: Solid Earth Journal of geophysical research : solid earth, 2021, Vol.126(2) [Peer Reviewed Journal] |
| ISSN: | 2169-9313 |
| DOI: | 10.1029/2020jb020655 |
| Popis: | Submarine landslides can be several orders of magnitude larger than their terrestrial counterparts and can pose significant hazards across entire ocean basins. The landslide failure mechanism strongly controls the associated tsunami hazard. The Tampen Slide offshore Norway is one of the largest landslides on Earth but remains poorly understood due to its subsequent burial beneath up to 450 m of sediments. Here, we use laterally extensive (16,000 km2), high-resolution processed 3-D seismic reflection data to characterize the upper Tampen Slide. We identify longitudinal (downslope, movement-parallel) chutes and ridges that are up to 40 m high, as well as extensional and compressional (cross-slope) ridges. This is the first time that longitudinal ridges of such size have been imaged in a deep marine setting. The first phase of the Tampen Slide involved the simultaneous translation of over 720 km3 of sediments along a single failure plane. This was followed by spreading along the head- and sidewall, and the formation of a retrogressive debris flow and slump, the volumes of which are insignificant compared to the first failure. The process responsible for movement of such a large sediment volume along a single glide plane differs significantly from that of other passive margin megaslides, which typically comprise numerous smaller landslides that fail retrogressively along multiple glide planes. The trigger mechanism (e.g., an earthquake), the presence of mechanically strong obstructions (e.g., volcanic structural high), and the number and location of weak layers may be key factors that determine whether megaslides develop along a single plane or retrogressively. peer-reviewed |
| Databáze: | OpenAIRE |
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