FORECASTING OF EARTHQUAKES

Press, Volume LXXIII, Issue 22005, 1 February 1937, Page 10

FORECASTING OF EARTHQUAKES

Definite Dangers Indicated DR. C. E. ADAMS EXPLAINS OFFICIAL POLICY j "It would be foolish and even dangerous to forecast earthquakes in New Zealand without absolute certainty," said Dr. C. E. Adams, formerly director of the Dominion Observatory, in an interview with "The Press" last evening. Dr. Adams wished to correct any wrong impressions which he said might have been gathered from the published statements of Major Edgar Booth, lecturer in physics at the University of Sydney, who recently, suggested that earthquake forecasting might be profitably practised in the Dominion. "The attitude of the Dominion Observatory has always been that until a prediction can be made with the same accuracy as predictions in astronomy for eclipses, etc., are made, the less said the better," Dr. Adams said. "There is no use keeping people always on their toes with imaginary predictions. It would surely be more sensible to put our buildings in order so that they would withstand the earthquake shocks." Dr. Adams said it should not be thought that a problem of vital importance in New Zealand as earthquake prediction had been neglected by the authorities. A beginning was made in the eighties by the late MiGeorge Hogben, who obtained the first two seismographs for use in New Zealand. He also established a system of reports from observers. Government activities in this work had always been crippled because of lack of funds, but gradually a number of seismographs had been obtained and now about 15 stations were established. In this way much precise information of the locations and origins of earthquakes had been obtained. All the details of this work were set out and easily accessible to the public in the publications of the Dominion Observatory and in the New Zealand Year Book. "Old Fiction" It was very interesting to see, Dr. Adams said, that Major Booth revived the old fiction about the accuracy of Japanese prediction of earthquakes. It had never been possible to find any definite evidence from the Japanese reports. The late Dr. Omori, who was one of the greatest seismologists in Japan, was a very careful man and never made any sensational announcements. It was true that from his observations he was able to predict the eruption of a volcano, and thereby save many lives, but he was by no means so successful with earthquake prediction. Dr. Omori satisfied himself that a series of earthquakes had ended in the period just before 1923 and he left the country in full confidence that there would be no serious shock for some time. He was in Sydney a short time later and was in the Riverview Observatory when the great Japanese earthquake of 1923 occurred. He blamed himself for not anticipating the disaster, and for the loss of may lives, and it is thought that concern about this accelerated his death. After every earthquake in New Zealand it was customary to receive reports from many predictors, Dr. Adams said. One man after the Napier earthquake claimed to have predicted it. Investigation was made, and it was found that he had forecast a shock in the Masterton area and further south. It could be imagined what would have happened had the people of Masterton acted upon this, and left tor Napier for safety. Certainty Desired Predictions might be made with a certain degree of accuracy, but this was not enough. It opened up great dangers, and the Dominion Observatory would not be a party to forecasting until they could be made with absolute certainty. t Information was being gathered, and the subject was being studied as fully as the means allowed. The observatory was working in conjunction with others to build up an adequate body of facts. The problem was a great one, and required the best brains among seismologists, mathematicians, physicists, and geologists. . A reasonable expansion or the scientific study of earthquakes was certainly required in New Zealand. The best course was for the observatory to proceed on its present basis with such additions in staff and equipment as the Government could afford. The work already done was sound and valuable, and a reorganisation seemed unnecessary. One important advance Would be the selection of a suitable man for training in instrumental seismology in Japan or California. Meanwhile it was surely the most sensible course, Dr. Adams said, to proceed with the improvement of New Zealand buildings, so that they could withstand earthquakes. Much of the danger at present was due to the erection of too heavy buildings. Not only should careful thought be given to new buildings but existing buildings should be made safe. Building Methods There were two opposed schools of thought on the question of buildings and earthquakes. The first endeavoured to fix buildings rigidly to the earth. This caused the whole force of the shock to be transmitted to the building, which was wrenched in every possible way. It was difficult to equip structures against this, as there was no adequate knowledge of the force and direction of the shock. The second school assumed that if j it was not possible to build strongly enough to resist shock, then it was, wise to dodge it by putting in a slipjoint between the earth and the buildings. The value of this method was well illustrated during the Napier earthquake. Buildings standing on the shingle at West Shore, without embedded foundations, and with slipjoints, escaped almost unscathed. In comparing these and the rigid buildings, Dr. Adams drew an analogy with the effect-of a high wind driving across a plantation of trees. Frequently, he said, rigid trees would be blown down, while the saplings, bending before the force of the wind, came up again after it had passed.