Sector collapse at Kick 'em Jenny submarine volcano (Lesser Antilles): Numerical simulation and landslide behaviour

Abstract

Kick 'em Jenny volcano is the only known active submarine volcano in the Lesser Antilles. It lies within a horseshoe-shaped structure open to the west northwest, toward the deep Grenada Basin. A detailed bathymetric survey of the basin slope at Kick 'em Jenny and resulting high-resolution digital elevation model allowed the identification of a major submarine landslide deposit. This deposit is thought to result from a single sector collapse event at Kick 'em Jenny and to be linked to the formation of the horseshoe-shaped structure. We estimated the volume and the leading-edge runout of the landslide to be ca. 4. 4 km 3 and 14 km, respectively. We modelled a sector collapse event of a proto Kick 'em Jenny volcano using VolcFlow, a finite difference code based on depth-integrated mass and momentum equations. Our models show that the landslide can be simulated by either a Coulomb-type rheology with low basal friction angles (5. 5°-6. 5°) and a significant internal friction angle (above 17. 5°) or, with better results, by a Bingham rheology with low Bingham kinematic viscosity (0 < ν B < 30 m 2/s) and high shear strength (130