Tsunamis

Long period sea waves produced by sudden/ abrupt movement of large volumes of water.

DEFINITION = unique high-magnitude waves caused by catastrophic events such as earthquakes, plate movements, volcanic activity, landslides and meteor impacts (Holden, 2005)

Over 90% of destructive tsunamis are caused by earthquakes of magnitude 7.5 or more.

Tsunamis generally occur along tectonic boundaries

• Approx 80% transpire within the ‘Ring of Fire’ = a geologically active area in the Pacific Ocean 

Wind waves have a wavelength (from crest to crest) of about 100m and a height of roughly 2-3m

A tsunami in the deep ocean has a wavelength of about 200 km - travels at well over 

800 km/hour

Large wavelength = wave oscillation at any given point takes 20 or 30 minutes to complete a cycle, amplitude of only about 1m…