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A. IjlAMURA 



4. Seismic zones. It will be seen that the origins of some of 

 these earthquakes are included within a narrow space or long belt 

 which corresponds to certain weak lines on the earth's crust. Such a 

 belt constitutes a so-called seismic zone. We may recognize ten such 

 zones in all, the most noteworthy being that which runs off n arly 

 ])arallel to the Pacific coast. The earthquakes belonging to this zone 

 have generally been un-local ; and the disasters due to tvnami or the 

 seismic tidal waves were sometimes more serious than the direct 

 effects of the earthquakes themselves. The seismic zone along the 

 Sinano-gawa Valley (zone III) has been ably studied by Prof. Omori, 

 who has shown tliat there exists a certain regularitv in the transference 



