Submarine landslide at Kick 'em Jenny volcano: analysis of an extreme scenario and its hazards
Presented by Dr. Frederic DONDIN on 23 Sep 2013 from 17:15 to 19:15
Type: Poster presentation
Session: Poster session
In the Lesser Antilles Volcanic Arc numerous sector collapse events have been identified in the last 30 years. So far 53 submarine deposits associated with sector collapse episodes have been identified off of the southern part of Montserrat and in the deep Grenada basin in the southern part of the arc. In both areas volumes of several tens of km3 have been identied. Some of these events were large enough to erode the submarine part of the island where they occurred e.g., Dominica, Martinique, St. Lucia or some previous submarine deposits (e.g., off of Montserrat south eastern coast). Kick 'em Jenny (KeJ) is the only submarine active volcano of the Lesser Antilles Arc. KeJ underwent 12 eruptions between 1939 and 2001 which makes it one of the most active volcanoes of the arc in the 20th century. KeJ is a strato-volcano located ca. 8 km north of Grenada on the steep (slope ca. 22°) eastern flank of the Grenada Basin. It culminates at −185 m u.s.l and the deepest sector within the vent is at ca. −264 m u.s.l. (Lindsay et al., 2005). According to Dondin et al. KeJ displays 3 episodes of sector collapses during its eruptive history recognized by 3 distinct generations of deposits off of its horseshoe-shaped structure. They showed that one of the deposit is ca. 4.4 km3 and has a runout of 14 km. Based on numerical simulations they also showed that the landslide behaved like a slump as it traveled as a stiff cohesive flow affected by minimal granular disaggregation and slumping on a non-lubricated surface. Dondin  previously revealed that such an event was capable of generating a regional tsunami with the closest islands being the most vulnerable. In this study we investigate the case of an extreme potential sub- marine landslide scenario that would involve the NW-SE sector of the current edifice of KeJ (Vcollapse ∼ 4.6 × 107 m3 ), and the tsunamigenic potential of such a landslide and its hazards for the surrounding islands. A numerical simulation of landslide propagation along an incline model is performed, retrieved from a preliminary slope stability analysis performed as a final step of a relative slope stability analysis after the Borselli et al.  method. The landslide numerical simulation and tsunami source were performed using the validated bi-fluid version of VolcFlow (Kelfoun et al. ), a code based on depth-integrated mass and momentum equations with a shallow water approximation for the mass-flow and the sea surface. The tsunami propagation is performed using FUNWAVE TVD (Shi et al. ), a validated code based on the resolution of the Boussinesq equations on a 30 seconds resolution bathymetry (GEBCO 08). References: Borselli, L., Capra, L. Sarocchi, D., De la Cruz-Reyna, S. (2011). Flank collapse scenarios at Volcán de Colima, Mexico: A relative instability analysis. Journal of Volcanology and Geothermal Research, 2008:51-65. Dondin, F. (2010). Simulations numériques et impact tsunamogène d'une détabilisation de flanc au volcan sous-marin Kick 'em Jenny, Petites Antilles. PhD thesis, Université des Antilles et de la Guyane, pp. 1-256. Dondin, F., Lebrun, J.-F., Kelfoun, K., Fournier, N., and Randriana- solo, A. (2012). Sector collapse at Kick 'em Jenny submarine volcano (Lesser Antilles) Numerical simulation and mass flow behaviour im- plications. Bulletin of Volcanology, 74:595607. GEBCO C.E.,( 2003). General Bathymetric Chart of the Ocean. British Oceanographic Data Center. Kelfoun, K., Giachetti, T. and Labazuy, P. (2010). Landslide-generated tsunamis at Réunion island. Journal of Geophysical Research, vol. 115, F04012, doi:10.1029/2009JF001381. Lindsay, J., Shepherd, J. B. and Wilson, D. (2005). Volcanic and scientific activity at Kick 'em Jenny submarine volcano 2001-2002: Implications for volcanic hazard in the southern Grenadines, Lesser Antilles. Natural Hazards, 34:1-24. Shi, F., Kirby, J. T., Harris, J. C., Geiman, J. D., and Grilli, S. T.(2012). A high-order adaptive time-stepping TVD solver for Boussi- nesq modeling of breaking waves and coastal inundation, Ocean Mod- elling, 4344, 3651, doi:10.1016/j.ocemod.2011.12.004.
Location: GEOMAR East shore
Address: Wischhofstr. 1-3 / D-24148 Kiel
- Dr. Frederic DONDIN Seismic Research Centre, The University of the West Indies, St Augustine, Trinidad & Tobago