Abstract. A modelling approach to understand the tsunamigenic potentiality of
submarine landslides will provide new perspectives on tsunami hazard threat,
mostly in polar margins where global climatic change and its related ocean
warming may induce future landslides. Here, we use the L-ML-HySEA (Landslide Multilayer Hyperbolic Systems and Efficient Algorithms)
numerical model, including wave dispersion, to provide new insights into
factors controlling the tsunami characteristics triggered by the Storfjorden
LS-1 landslide (southwestern Svalbard). Tsunami waves, determined mainly by
the sliding mechanism and the bathymetry, consist of two initial wave
dipoles, with troughs to the northeast (Spitsbergen and towards the
continent) and crests to the south (seawards) and southwest (Bear Island),
reaching more than 3 m of amplitude above the landslide and finally merging
into a single wave dipole. The tsunami wave propagation and its coastal
impact are governed by the Storfjorden and Kveithola glacial troughs and by
the bordering Spitsbergen Bank, which shape the continental shelf. This
local bathymetry controls the direction of propagation with a crescent shape
front, in plan view, and is responsible for shoaling effects of amplitude
values (4.2 m in trough to 4.3 m in crest), amplification (3.7 m in trough to
4 m in crest) and diffraction of the tsunami waves, as well as influencing
their coastal impact times.