News Note 1 
THE ADDITION OF seven tide stations in Chile will give Alaska, Oregon, Washington, Hawaii, 
and many Pacific Basin nations up to two or more hours additional warning time when a de- 
structive tsunami is generated off the Chilean coast. 
This was disclosed by Mark G. Spaeth of the Environmental Science Services Administration’s 
Coast and Geodetic Survey. 
Spaeth, a geophysicist in the Office of Seismology and Geomagnetism, made the disclosure 
following his return from an 18-day trip to South America designed to improve the Tsunami 
Warning System in the Pacific. The System is operated by the Coast and Geodetic Survey in 
Honolulu. 
Spaeth conferred in Valparaiso with officials of the Chilean Hydrographic Institute, and agree- 
ment was reached to supply reports on tide conditions from seven additional tide stations to 
the C&GS Honolulu Observatory, which issues the warnings. Until now, there were only two 
participating tide stations in the Tsunami Warning System along the entire coast of South Amer- 
ica — at Valparaiso, Chile, and Callao, Peru. 
"This should greatly reduce the time needed to confirm the existence of tsunamis originating 
along the South American coast," said Spaeth, "and provide up to two or more hours additional 
warning time to people throughout the Pacific Basin when a destructive wave is generated." 
A I960 tsunami off the Chilean coast caused deaths and extensive damage in Chile, Hawaii, 
the Philippines, Japan, and Okinawa. In spite of six hours’ warning, 61 persons were killed 
in the Hawaiian city of Hilo. All Chilean coastal towns between the 36th and 44th parallels were 
destroyed or severely damaged by earthquake and the ensuing tsunami. In California, a half- 
million dollars’ damage was caused to harbor installations and ships at Los Angeles, San Diego, 
Cresent City, and Half Moon Bay. Crescent City was also the scene of widespread destruction 
from a tsunami generated by the March 1964 earthquake in Alaska. Eleven persons lost their 
lives in this community. 
Spaeth also conferred with scientists in the Panama Canal Zone, Peru, and Ecuador. As a re- 
sult, further steps to strengthen the Warning System may be taken in these areas. 
"Tsunami" is the Japanese name for a seismic sea wave, the destructive oceanic offspring of 
earthquakes and volcanic eruptions. Although frequently, and mistakenly, called tidal waves, they 
are not related to the tides. 
The phenomenon is a series of ocean waves, not unlike those made when a pebble is dropped 
into a pond, which travel up to 600 miles or more per hour. In the open ocean the crests of the 
waves are sometimes hundreds of miles apart and always only a few feet high. As the tsunami 
nears the coast, the speed diminishes and the waves increase in height. They cannot be seen 
from the air, nor felt aboard ships in deep water. This is why tide stations are essential in the Warn- 
ing System — to report to the System Headquarters at Honolulu any change in water level, following 
large earthquakes, that could indicate a tsunami has been generated. The Honolulu Office in turn 
alerts Civil Defense agencies in communities the tsunami may strike so the low-lying areas can be 
evacuated. 
The Tsunami Warning System was established by the Coast and Geodetic Survey following 
the disastrous Aleutian tsunami of April 1, 1946, which struck the Hawaiian Islands without warn- 
ing, leaving 159 persons dead and about $25 million property damage. But this was the last 
tsunami to strike Hawaii without warning, because the Coast and Geodetic Survey developed 
and installed a network of seismographs around the Pacific to detect the earthquakes which cause 
tsunamis. 
1 From: Earthquake Information Bulletin 1(3): 1-4 (1967). 
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