Studies of submarine slope failures in the North Atlantic: Causes, timing and consequences

• Main Author: Elger, Judith
• Format: Thesis
• Language: English
• Published: 2016
• Subjects: North Atlantic
• Online Access: https://oceanrep.geomar.de/id/eprint/35470/; https://oceanrep.geomar.de/id/eprint/35470/1/Elger_Thesis.pdf

Submarine landslides are a significant geohazard to offshore infrastructure and coastal areas. They occur worldwide on the slopes of volcanic islands and continental margins. In the NE Atlantic, many large-scale Holocene and Pleistocene submarine landslides are located at the mouth of cross-shelf troughs and were probably triggered by earthquakes. Discussions on critical preconditioning processes for slope failure relate to cyclic sedimentation patterns during glacial periods, gas hydrate dissociation caused by changing pressure and temperature condition, and over-steepening due to toe erosion or uneven sedimentation patterns. However, the significant geological destabilizing processes leading to slope failure are still not fully understood and require further studies. The main objective of this thesis is to gain new insights about the initiation of submarine landslides and to identify which particular destabilizing preconditioning processes make slopes prone to failure. This aim is addressed by the reconstruction of the failure chronology of the newly discovered Fram Slide Complex, and by a numerical modeling approach that investigates a new preconditioning process related to gas hydrates. (.)