Frank White wrote:

massive chunks of the Canary Islands (in the Atlantic) and the
Hawaiian Islands (in the Pacific) that are at risk of breaking
loose and sending walls of water even HIGHER than the Sumartarn
quake at their respective shores...


URL of one of the sites discussing Hawaii land slides and tsunamis:

http://www.mbari.org/volcanism/Hawaii/HR-Landslides.htm

A seamount can also have a tsunami producing land slide.

Animated GIF of the tsunami expected when the Cascadia subduction fault
next acts up. Part of it is pointed straight at Seattle.

http://quake.usgs.gov/tsunami/GIFanimation.html

Averages 800 yrs. Last major quake was 700 yrs ago.