Waves | 11 
some older editions of Coast Pilots and to compare them with 
more modern editions. They contain warnings of all sorts of 
mysterious rocks and shoals which are now known not to 
exist. 
UCED BY UP- 
THRUST OF BOTTOM 
TIDAL WAVES NOT RELATED TO TIDES 
A severe submarine earthquake causes a “doming up” of 
the surface of the sea for a considerable area, and then huge 
so-called tidal waves diverge from the area in all directions 
