358 ANNUAL REPORT SMITHSONIAN INSTITUTION, 1962 



IT 



Figure 6— Distance from shore that a wave can travel in indicated times, and estimated 

 position of Maremoto if it began at the same instant as the earthquake. 



of the sea floor, during the displacement of the fault, produced a part 

 of the movement. 



2. Benioff has, for years, been proposing that tsunamis are gener- 

 ated by the coupling of surface waves in the earth to sea waves [3, 

 17, 19]. The strain seismograph records from Nana, Peru, show that 

 waves of the correct period existed. The waves may have been pro- 

 duced by a flexing, due to vertical fault movement, or by a vertical 

 warping produced by f rictional and inertial forces during strike-slip 



