- 12 March 2013 | Environment
The earthquake zones off of certain coasts - like those of Japan and Java - make them especially vulnerable to tsunamis.
The new study authored by Utku Kanoglu and Costas Synolakis has changed the way scientists explain the rules of tsunami. Until now, it was largely believed that the maximum tsunami height onshore could not exceed the depth of the seafloor.
The recent research shows that when focusing occurs, the scaling relationship breaks down and flooding can be up to 50 percent deeper with waves that do not lose height as they get closer to shore.
Also, it was thought that tsunamis usually decrease in height continuously as they move away from where they are created and grow close to shore, just as wind waves do. The study's authors instead suggest that the crest of the tsunami remains fairly intact close to the source.
"Our results show that some shorelines with huge earthquake zones just offshore face a double whammy: not only they are exposed to the tsunamis, but under certain conditions, focusing amplifies these tsunamis far more than shoaling and produces devastating effects", explained Utku Kanoglu, professor at the Middle East Technical University.
Remember that tsunami waves are not surfable. And what is a tsunami?
Learn the effects of shoaling and refraction in wave height and how waves are formed.