302 HOBBS— SEISMIC GEOLOGY. [April 24, 



more destructive to human life than the shocks which proceeded it. 

 The earthquake water wave which inundated the shore of Japan on 

 June 15, 1896, destroyed human Hves to the number of 29.953. 

 Such waves have been especially destructive along the western coast 

 of South America. The new seismology, by instrumental methods, 

 points more and more definitely to the cause of such disturbances in 

 the subsidence of great sections of the neighboring ocean floor; yet 

 with the exception of relatively small waves within the Mediter- 

 ranean, we are without observational data in the form of soundings 

 in confirmation of this hypothesis. The bottom of the ocean is each 

 year being charted in new areas, and we are fast accumulating data 

 on which to base a decisive series of observations to settle this im- 

 portant question. This will certainly be one of the larger problems 

 for investigation in seismic geology. 



Conclusion. — It has been possible to indicate a few only of those 

 directions along which efifort will be directed in the early future of 

 seismic geology. From this summary, I think it will be seen that 

 there remain no other fields of investigation so long neglected and 

 yet so full of promise in important discoveries, which are likely to 

 touch so intimately the lives and happiness of human beings. What 

 we have already learned is much of it as yet only half learned, and 

 we need careful experimentation on lines already marked out, so 

 that recommendations may be made for adapting our lives to future 

 seismic conditions. Probably nine tenths of the danger from earth- 

 quakes can be avoided through practical methods of construction, but 

 the relative cost of the difl^erent means of securing immunity must 

 be carefully considered. The studies which are necessary are on 

 such a scale that they call for generous government support, and 

 it cannot be too strongly urged that the United States government 

 undertake a work so clearly demanded by the situation. This sup- 

 port should be nothing less than the foundation of a bureau for 

 earthquake investigation, with regular appropriations sufficient to 

 carry out studies by a system of correlated earthquake stations, and 

 also upon the ground of each devastated region whether it be at 

 home or abroad. 



University of Michigan, 

 April 21, 1909. 



