Abstract
The areas which should be watchful against the tsunamis are (1) the V-shaped or U-shaped bays, (2) the tied islands, and (3) the areas which lie between the points and the roots of the headlands. The highest wave in Hokkaido (Japan) attacked western side of Erimo He adland on May 24, 1960. The distributions of energies along the coast of a head-land being attacked by the tsunamis of various directions of advances, can be analysed by the calculus of variations. With the developments (the increases of the populations) of the areas around the headlands, this investigation should be pushed.
