| Titre | Assessing submarine slope stability through deterministic and probabilistic approaches: a case study on the west-central Scotia Slope |
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| Auteur | MacKillop, K; Fenton, G; Mosher, D ; Latour, V; Mitchelmore, P |
| Source | Submarine landslides - assessing the stability of submerged slopes; par Urlaub, M (éd.); Geosciences vol. 9, issue 1, 2018 p. 1-18, https://doi.org/10.3390/geosciences9010018  Accès
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| Image |  |
| Année | 2018 |
| Séries alt. | Ressources naturelles Canada, Contribution externe 20180395 |
| Éditeur | MDPI AG |
| Document | publication en série |
| Lang. | anglais |
| DOI | https://doi.org/10.3390/geosciences9010018 |
| Media | papier; en ligne; numérique |
| Formats | pdf |
| Province | Nouvelle-Écosse; Région extracotière de l'est |
| SNRC | 10 |
| Région | Scotian Slope; Océan Atlantique |
| Lat/Long OENS | -63.6667 -60.3333 43.5000 41.5000 |
| Sujets | sédiments marins; boues; dépôts de glissement de terrain; sables; carottes de sédiment marin; stabilité des pentes; analyses de la stabilité des pentes; glissements de pentes; détermination des
contraintes; essais de cisaillement; glissements de terrain; coulées de débris; glissements; érosion; marges continentales; talus continental; géostatistiques; modèles; carottages par piston; charge de fond; secousses séismiques; pressions
interstitielles; chenaux; masse volumique en vrac; resistance au cisaillement; lithologie; couleur; corrélation; Évaluation des risques; Méthodologie; géologie marine; géologie des dépôts meubles/géomorphologie; géomathématique; géologie de
l'ingénieur; Phanérozoïque; Cénozoïque; Quaternaire |
| Illustrations | cartes de localisation; cartes géolscientiques généralisées; profils; coupes lithologiques; tableaux; graphiques; graphiques |
| Programme | Géoscience en mer |
| Diffusé | 2018 12 28 |
| Résumé | (disponible en anglais seulement)
A simplified geostatistical approach was adopted to assess the effect of spatial variability of soil properties on slope stability analysis in order to
understand continental margin geologic processes and potential geohazards for an area of the central Scotian Slope, offshore Nova Scotia, Canada. The analyses are conducted on piston core samples, thus are restricted to ~12 m sub-seabed; however, the
approach provides insight into the general effects of spatial and temporal variability. Data processing using geostatistics and assessment of spatial correlation are used to characterize the current dataset. A deterministic assessment was performed
for both non-spatially averaged and spatially averaged core sections. The results indicate that the estimated factor of safety increased by about 30% when spatially averaged values were used. A probabilistic model is introduced to assess reliability
of the slope. The approach makes use of estimates of both the mean and variance of input random variables (e.g., Su and gamma-b). The model uses an exact probabilistic formulation for the total stress stability analysis and a Taylor series
approximation for the effective stress stability analysis. In both cases, the mean and variance of the factor of safety are computed, leading to estimates of failure probability. The results suggest that the deterministic analysis is conservative
with respect to slope reliability, although they do not lead to an estimate of the probability of failure. While these results indicate sediment instability is largely unlikely under static conditions, the reality is that many examples of submarine
slope failure are observed in the geologic record. These results suggest that cyclic loading (earthquakes) or pre-conditioning factors (elevation of pore pressures) are critical for slope instability on the Scotian Slope. |
| GEOSCAN ID | 313620 |
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