“…For instance, we do not take into account material heterogeneity, segregation and fragmentation processes, bed erosion and incorporation of air and/or water, or density variations that can be caused by the expansion or contraction of the material and their impact on pore fluid pressure [see Delannay et al, 2017 for a review of processes]. HySEA was developed by the EDANYA group [Asunción-Hernández et al, 2012, Asunción et al, 2013, Castro Díaz et al, 2005, 2006, 2008a,b, Macías et al, 2015 and has been successfully used to simulate tsunamis generated by landslides [Kirby et al, 2022 (for a benchmarking exercise); Macías et al, 2021, Esposti Ongaro et al, 2021. From the depth-averaged equations, six unknowns are solved by the model, (h 1 , u 1x , u 1y ) and (h 2 , u 2x , u 2y ), representing the vertical height and horizontal velocity of the fluid (index 1) and granular layer (index 2), respectively, averaged in the vertical direction.…”