Time ripe for big quakes?

Press, 7 April 1979, Page 9

Time ripe for big quakes?

NZPA-Reuter Paris American and Japanese scientists have said that the time may be ripe for big earthquakes in heav-ily-populated regions of their countries.

They based their fears on evidence of large seismic movements at regular intervals dating back for centuries in southern California and the industrial coastal area of Japan, west of Tokyo. The scientists were attending an international symposium on earthquake prediction organised by the United Nations Educational, Scientific, and Cultural Organisation. Dr Robert Wesson of the United States Geological Survey told a news conference that substantial seismic disturbances recurred on average once every 160 years in southern California. The last such movement, in the Los Angeles area, was in 1857, Dr Wesson said, “so we are now within range of this average.”

Another warning signal was the appearance in 1975 of “land uplift” of as much as 0.5 metre in the region between the Pacific coast and the Arizona border. “We do not frankly understand the origin of this uplift, so we shall be concerned about that region,” Dr Wesson said.

Professor Tsuneji Rikitake, of the Tokyo Institute of Technology, said Japanese scientists were expecting what he described as a very big earthquake in the Tokai area between Tokyo, Nagoya, and Osaka.

“You can imagine what would happen if an earthquake hit our fast bullet train, travelling at 200 km/h,” Professor Rikitake said.

The Japanese expert said earthquakes hit the area on average once in 120 years. The last big movement there was in 1854, when 20,000 people were killed.

“We are making every sort of measurement to test the behaviour of the Earth’s crust, and the accumulation of pressure,” Professor Rikitake said.

The Japanese Meteorological Agency in Tokyo kept a day and night watch, and was ready to summon a prediction council of six university professors if danger threatened.