Some of the largest tsunamis known have been generated within closed waters where the amplitude of the wave is created because of the constriction of the geography. In 1958 (07/09),
an earthquake caused a landslide into Lituya Bay in Alaska, a constricted fiord bordering upon 3 glaciers in the southern panhandle. The resulting wave reached a height of 1,720 feet (524 m) as measured by the affected foliage. This is the world record for a historical tsunami.
This gives a whole new meaning to that common term, "100 year flood", doesn't it?
Hey, that’s only a third of a mile. ;’) The amazing thing about it is, not only were there witnesses, some of them survived. Talk about your wrong place at the wrong time...