TSUNAMIS Alexandra Norris

Tsunamis Deep water Small amplitudes and long wavelengths Travel at well over 800 km/h Shallow water Wave Shoaling will compress and slow the wave to around 80 km/h Wavelength will decease and amplitude will increase

Seismic tsunamis

Quantification of Tsunamis Sieberg (1927) Soloviev-Imamura tsunami intensity scale H av is the average coastal height Hatori(1986) Tsunami magnitude M t H is amplitude measured by tide gages, and Δ is the shortest path form the earthquake epicentre to the tide station Murty and Loomis (1980) E is energy (ergs)

Numerical modeling The MOST-3 solves the nonlinear shallow-water wave equations η is the wave displacement, d is the undisturbed water depth, u is the horizontal velocities, g is the acceleration due to gravity, R and is the bottom friction term.

Meteotsunamis Tsunami-like waves that are induced by atmospheric processes rather than by seismic sources Same periods, same spatial scales, similar physical properties, but Less energetic then seismic tsunamis Caused by atmospheric gravity waves, pressure jumps, frontal passages, squalls, etc. “rissaga” in Balearic Islands, “marubbio” in Sicily, “milghuba” in Malta, “abiki” in Nagasaki Bay, Japan

Megatsunamis Informal name for Tsunamis with extremely large amplitudes Originate from landslides or impact events 1792: Mount Unzen, Japan 1958: Lituya Bay, Alaska, USA 1963: Vajont Dam, Italy

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