Frequency and triggering of small-scale submarine landslides on decadal timescales: Analysis of 4D bathymetric data from the continental slope offshore Nice (France)
| Autor: | Alfredo Taboada, Sébastien Migeon, Emmanuel Tric, Alexandre Dano, Françoise Couboulex, Maëlle Kelner, Thomas Lebourg |
|---|---|
| Přispěvatelé: | Géoazur (GEOAZUR 7329), Institut national des sciences de l'Univers (INSU - CNRS)-Institut de Recherche pour le Développement (IRD [France-Sud])-Centre National de la Recherche Scientifique (CNRS)-Observatoire de la Côte d'Azur, Université Côte d'Azur (UCA)-Université Côte d'Azur (UCA), Géosciences Montpellier, Institut national des sciences de l'Univers (INSU - CNRS)-Université de Montpellier (UM)-Université des Antilles (UA)-Centre National de la Recherche Scientifique (CNRS), Université Côte d'Azur (UCA)-Institut national des sciences de l'Univers (INSU - CNRS)-Institut de Recherche pour le Développement (IRD [France-Sud])-Centre National de la Recherche Scientifique (CNRS)-Observatoire de la Côte d'Azur, Université Côte d'Azur (UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA) |
| Rok vydání: | 2016 |
| Předmět: |
geography
geography.geographical_feature_category 010504 meteorology & atmospheric sciences Continental shelf [SDU.STU]Sciences of the Universe [physics]/Earth Sciences Sediment Geology Landslide 010502 geochemistry & geophysics Oceanography 01 natural sciences Deposition (geology) 13. Climate action Geochemistry and Petrology Erosion Bathymetry Submarine pipeline 14. Life underwater Geomorphology 0105 earth and related environmental sciences Submarine landslide |
| Zdroj: | Marine Geology Marine Geology, Elsevier, 2016, 379, pp.281-297. ⟨10.1016/j.margeo.2016.06.009⟩ |
| ISSN: | 0025-3227 |
| Popis: | International audience; Time-series bathymetric data acquired from 1967 to 2011 are used to evaluate the morphological evolution of the continental shelf and upper continental slope off the city of Nice (SE France, Ligurian Sea). Mapping in water depths of 0–300 m was undertaken to identify the changing morphology of landslide scars and their erosive chutes. Quantitative Digital Terrain Model (DTM) comparisons reveal areas of erosion and deposition over intervals of 5–8 years. Sediment remobilization events on the upper slope (above depths of 200 m) are frequent and significant; landslide scars with volumes > 25,000 m3 can occur with frequencies of < 8 years. Shelf break retreat toward the coastline can reach 60 m over 7–8 years where the continental shelf is wider (> 200 m). Periods of quiescence (1980–1990 and 2006–2011) are seen to alternate with periods when rapid retrogressive failure increase sediment volumes eroded from the upper slope-shelf transition by an order of magnitude (1999–2006). Temporal variations in landslide activity were correlated to several potential triggering factors that individually would not induce failures, including earthquake activity, rapid deposition of fine-grained sediments on a steep slope, and rainfall leading to fresh groundwater circulation below the shelf. This 4D bathymetric study suggests that over the last 50 years the most important factor triggering landslides offshore Nice is overpressure due to freshwater outflows. |
| Databáze: | OpenAIRE |
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