OCEAXOGRAPHY 183 



The network has functioned with precision and saved many lives 

 and millions of dollars. The seismologists and tide observers of the 

 network are proud of the fact that they have not misssed a warning or 

 given a false alarm during their 14 years of operation. 



In that regard, we say we did not give a false alarm. We have called 

 alarms or warnings when we knew a tsunami was coming but the 

 wave may have been only a few feet in height. "We have no way 

 of predicting this. 



Thus at times even though they evacuated waterfront areas, the 

 waves were just high enough to slap into the docks. 



I think the reason for the loss of life this time was because the two 

 previous tsunamis did not generate large waves, and, as this was at 

 midnight, I feel that the people did not get out even though the 

 warning somided in these areas. 



I have one other thing which I would like to show you gentlemen, 

 if I may. TMs is a travel-time chart. On tliis chart we have plotted 

 the location of the epicenter. When that earthquake occurred, it 

 sent seismic waves through the groimd and, as you can see, it took 12 

 minutes to Tucson, 15 minutes 10 seconds to Fairbanks, 13 minutes to 

 Honolulu, and so forth. 



The minute these stations recorded an arrival of a major earth- 

 quake, a bell rang in their obseiwatories, the seismologists awakened 

 and innnediately scamied their seismogram and fomid out how far 

 this earthquake was from their actual location. They wired tliis 

 information to Honolulu. Honolulu knew that the earthquake was 

 say 6,000 miles from Fairbanks. They swing distance arcs on a globe 

 and the intereection of those arcs must be the epicenter or focal point 

 of the earthquake. 



The next point is to determme whether or not this earthquake, 

 which occurred under the sea, was generating a tsimami. That is very 

 difficult. Nobody knows exactly why most of them do not generate 

 tsunamis and a few of them do. I have heard the reasoning that if 

 an earthquake occurs right where the water and land join, it would 

 create a tsmiami because all this pressure would be released into the 

 water. 



On the other hand, if it is a mile down, it might not create a 

 tsmiami. That is just a theory. 



Honolulu will immediately wire these different tide stations and 

 tell the observers to read their gages and note whether this long 

 period wave, whose period is anywhere between 15 minutes and a half 

 hour, has been recorded. They can tell how long it will take that 

 wave to travel between the epicenter and an individual station. 



The minute they receive a positive report that is definite, they will 

 issue a warning. 



The other day they put out the actual warning, not the advisory, 

 514 hours before the wave hit. I think they waited to be sure that 

 Tahiti still recorded a wave. "Wlien they found that there was a big 

 wave at Tahiti, they put out the warning. 



The reason for checking this is that you do not want to put out 

 umiecessaiy warnings. If you do people will not get out of their 

 homes but will just brush them off. 



Mr. Miller. Was there not a great deal of damage done in Tokyo? 



Captain Earle. Yes, sir; there was. That wave traveled through 

 liere. I have noted articles that said the Japanese were not warned 



