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Arctic Geo-hazards, Geo-fluids and Climate Change (ARCTIC GEO-HAZARDS)
Date du début: 21 mars 2014, Date de fin: 10 févr. 2018 PROJET  TERMINÉ 

Recent studies indicate that water and methane stored in deep sediments might be abruptly mobilized by warming due to Climate Change.At the particularly climate-sensitive Arctic margin, sudden migration of such deep geo-fluids might cause submarine slope instability andlandslides, and might even result in a significant release of methane into the atmosphere. Submarine landslides threaten infrastructuresand can generate tsunamis. Today’s high interest in Arctic resources indicates an impending increase in industrial seafloor usage,especially near coastal areas. During past climate oscillations, protruding and retreating Arctic glaciers favored deposition of alternatingsandy and clayey layers on the slope. These sediments differ in porosity, density and water content because they experienced disparatedepositional history and mechanical consolidation, due to past waning and waxing of grounded glaciers. Ongoing temperature rise mayhelp to free geo-fluids that change current flow rates. Upward fluid migration in fractures and sediment layers with different properties willcause local high pore pressures that will decrease the shear strength of layers and potentially trigger submarine slides. Similar geologicalscenarios occurring during past interglacial periods are viable for large-scale submarine slides discovered in the region.This project aims at developing a detailed 3D numerical modeling of fluid flow at a type-example of an Arctic continental margin. We willdetermine the hydrogeological system, and numerically simulate scenarios of changing fluid flow rates, and how they affect pore pressureto study their potential effect on slope stability along the continental slope offshore Svalbard Archipelago (Norway). Modeling will be basedon available, unpublished, recently collected 2D seismic data, multibeam bathymetry data, and core data from the region. Structuralinformation will be complemented with laboratory work that will provide sediment properties.