THE EARTHQUAKE PROBLEM HECK 



375 



The problem, then, is prevention of disaster due to moderately 

 severe earthquakes and reduction of damage due to great ones. Engi- 

 neers are beginning to agree that major structures should be designed 

 with regard to earthquake stress if the history of the region indi- 

 cates that they are likely to be subjected to such stress. They are 

 recoo-nizino: the lack of information and are demanding that more 

 accurate information be obtained. 



— ^ — ^jVwv^^' vv^a^vawa/vw^ Wk|\|\/W^^V 'v^'Wvvwk.^^WV wivw\v-*»v^ Aiwyw^/^v^ivsAAv^ ; \/ • \ « . 



FiGDRB 5. — Record made by Wood-Anderson seismometer at Tucson Magnetic Observa- 

 tory, Tucson, Ariz., on November 18, 1929. Grand Banks earthquake. E.-W. 

 component 



It is of particular interest to know that in 1931 Congress pro- 

 vided funds for undertaking this work which will start early in 

 1932. Suitable plans have been worked out in cooperation with 

 organizations on the Pacific Coast and the first instruments for 

 securing information regarding earthquake motions of interest to 



ll'-VrJ'-^y\r\f-^^^^ 



FiGCKB 6. — Seismngram recorded by Wenner horizontal component seismograph at 

 United States Bureau of Standards, Washington, D. C. 



engineers will be made in this region. This does not mean that this 

 is the only part of the United States where strong earthquakes may 

 occur. In fact, the most severe earthquakes in this countr}'^ during 

 the past five years have been in the East, but it is a region where 

 earthquakes of severity have occurred in a number of localities and 

 therefore with suitable distribution of instruments earlier results 

 may be anticipated there than elsewhere. Furthermore, the demand 



