The Dominion THURSDAY, JUNE 20, 1929. THE EARTHQUAKE

Dominion, Volume 22, Issue 226, 20 June 1929, Page 10

The Dominion THURSDAY, JUNE 20, 1929. THE EARTHQUAKE

' Familiarity with earth tremors of varying, hut rarely .j e ™u s , people in this country to regarcl these i "“ r SeisSo£c” C sdesS Ihas 1 has made very great advances during the beismo g , su j t o f co-operative organisation n St the l "conecSn of daa from all over the world. Investigation has been directed chiefly upon three points: the cause ° f s the possibility of The re uKuined ;£7a7 ~' y S”ara S^si^slX'^S 1 general iUSTtrSelssum^s Tpon'St investigations that there was a close connection beiweon earthquakes and volcanic activity has been considerably modified i the light of collaborated data. That there may be some■ c ° n is admittedly possible, but it has also been demonstrated that seismic disturbances may occur independently of volcanic a £tion. • > President of the Geological Society and a past-President o the Seismological Society, of America, points out that the California earthquake of 1906 was a most instructive occurrence. There were no volcanoes connected with it, so that idea was not invoked. It was, he says, a sudden slip on an old rift n the earns crust estimated at more than 180 miles long and at least 25 miles deep ’ His theory is that the actual disturbance was the culminatin point in a more or less prolonged strain exerted by the pressure of an immense mass .upon a weaker section,, and that these stresses distributed in zones which correspond with the deeper parts of the ocean “One great belt of ocean deeps, he says, borders the two Americas, extends down the coast of Asia into the East Indian Archipelago, and continues toward New Zealand. . Dr. Willis’s theory of stresses is supported by conclusions arrived at by Dr. Imamura, of the University of Tokio, and an Internationa authority on seismology. On the possibility of predicting advent of an earthquake, he asserts that many earthquake shocks are preceded a few hours by a slow, minute, imperceptible local tilting of the earth’s crust, like the bending that may sometimes be seen to precede the final fracture of an overloaded piece of timber. With an extremely delicate apparatus, described as a clinogiapn, he detected, he claims, the preliminary warnings of. the Japanese earthquake of 1927. There has since been installed in his country a network of clinograph stations, which, it is asserted, will announce some hours ahead the least tilt by the ringing of a bell, thus giving people time to escape from buildings. . The enormous destruction and loss of life occasioned by earthquakes occurring in thickly-populated centres has directed attention to the problem of earthquake-proof buildings. On this point, Dr. Willis declares that “it is not the well-built skyscraper, which rests on deep foundations set on rock, but the skimped brick or weak ferro-concrete building for which we should feel anxious. In this connection some interesting experiments in building construction have been carried out in Tokio. The new Mitsui Bank building is a notable instance. As the result of collaboration between. Japanese scientists and American structural engineers, certain, important departures from conventional design were made to suit Japanese conditions, and the result is a building regarded as absolutely earth-quake-proof, at an increase of from 10 to 15 per cent, of the ordinary cost. It remains to be seen, of course, how this building will stand the test of Tokio’s next severe earthquake. , For years after the big New Zealand earthquake of the fifties, architects and builders pinned their faith on wood. It has been scientifically demonstrated, however, that the well-constructed steel reinforced building answers satisfactorily the safety requirements evolved by scientific study and experiment. This week’s disastrous experience in the South Island should provide useful data in this respect. Further, it should impel public opinion to insist upon more encouragement for local scientific research work in the problems of siesmology.