Landslides surfing on water: a preliminary study

Abstract

We conjecture that in some cases, landslides impacting onto a water surface might acquire a vertical momentum that makes them slide horizontally at the water level, instead of plunging immediately into deep water, a process that we name surfing. An example of this behavior could be the recent (2002) landslide from the Sciara del Fuoco (Stromboli, Italy), which caused a tsunami with 10-15 meters high run-up waves. By examination of photographs, laboratory experiments, theoretical estimates, and numerical calculations, we preliminarily investigate the surfing conditions for landslides. The effect might also have an impact on the generation and propagation of tsunami waves