Why the Chile quake tsunami was smaller than feared

[Fumesucker]

http://www.newscientist.com/article/dn18588-why-the-chile-quake-tsunami-was-smaller-than-feared.html

Tim Henstock of the National Oceanography Centre at the University of Southampton, UK, speculates that the reason might be that Saturday's earthquake ruptured a relatively small segment of fault – around 350 kilometres. The length of fault rupture determines the distance at which a tsunami begins to lose energy. By comparison, the magnitude-9.1 earthquake that generated the 2004 Indian ocean tsunami ruptured around 1600 kilometres of fault.

Chile's recent tsunami was also highly focused. "It was quite a directed tsunami, rather than a 'stone in a pool' type propagation," explains Simon Haslett of the University of Wales, Newport. The tsunami was severe at the coast nearest the epicentre, and westward at the Juan Fernandez Islands, but the energy and height were lost quickly in other directions, he says.

Furthermore, the relatively deep origin of the earthquake – 35 kilometres – may have minimised the uplift on the sea floor that displaced the water. "The Chile quake was smaller and deeper than the Indian Ocean quake of 2004, so less energy was released and, most importantly, less of this reached the surface," says Bill McGuire of University College London.

[aquart]

1. Cool. We can think of it as a drill.

[GeorgeGist]

2. Speculation is not proof.

Look it up.

[clu]

3. ok tnx

n/t

[Fumesucker]

4. Speculation by an expert in the field is considerably more likely to prove true..

Than speculation by someone who knows nothing about it.

It might be years or decades before "proof" becomes available, I thought people might like to have a look into what some experts were thinking.. Silly me.