Triggers and consequences of landslide-induced impulse waves – 3D dynamic reconstruction of the Taan Fiord 2015 tsunami event

Natural multi-hazards as landslide-induced tsunamis require a multi-disciplinary approach to analyze the cascade effects that pose significant threat mountain communities and surrounding territory. This paper comprises detailed study of both landslide evolution wave dynamics October 2015 Taan Fiord (Alaska) tsunami event, which represents highly valuable case for generic methodology development single code applications using numerical software Flow3D testing its applicability cascading hazard evaluation. First, geomorphological analysis unstable slope is performed by elaborating diverse digital elevation models, where vertical displacement −90 m observed before final collapse, influence listric faults within slide body results in bulging glacier at toe. Data from time-series analyses suggests retreat (and reduction local buttresses) critically destabilized leading catastrophic failure. The reconstructed volume estimated be 49.4 Mm3, 26 Mm3 entered fiord triggered tsunami. Second, are recreated with Flow3D. Both dense fluid granular media models used compared verify their performance initiating impulse wave, measured impact speed ranging between 32 49 ms−1 triggers maximum amplitude about 95–99 m. run-up 193 Hoof Hill Fan approaches, but general overestimations (about 9–12%) observations, area, computed inundation process. A good approximation along entire length found propagation approach. Beyond Taan-Fiord evaluation hydraulic other settings, this work points out (i) necessity high temporal resolution multi-stage failure properly estimate volume, (ii) applied reproduce event on one only, (iii) how these can adopted develop maps related potential hazards natural basins.