EARTH TREMORS

New Zealand Herald, Volume LXXIV, Issue 22628, 16 January 1937, Page 12

EARTH TREMORS

SUSCEPTIBLE AREAS POSITION OF AUCKLAND NO ABSOLUTE IMMUNITY LIVING IN FOOLS' PARADISE The generally current opinion that Auckland is immune from the danger of earthquakes was referred to by Mr. R. C. Hayes, acting-Dominion Seismologist, in addressing the physics section of the Science Congress yesterday. That this idea was erroneous was amply demonstrated by a particularly violent earthquake which occurred near the town in 1834-35. "In fact," said Mr. Hayes, "places which are continually experiencing small tremors are nore likely to avoid any serious upheavals than places where m> shocks have been recorded over a long period. The minor tremors act as safety valves in relieving the stresses which are continually being built up." Mainly Occur in March The importance of- earthquakes .in the Dominion was fully realised by the authorities, and, apart from the two main observatories at Wellington and Christchurch, there were eleven subsidiary stations in Now Zealand, and one in the Chatham Islands. In addition a seismograph would be installed shortly at Kaitaia, providing valuable coverage in the extreme north. Tn Australia there were only three seismological stations, although it was expected another station would be opened shortly. In investigating past earthquakes in the Dominion, Mr. Hayes said, he found that they tended to occur mainly March, with a secondary maximum in September, while the month of January was most free from disturbances. Earthquakes occurred most frequently over the central portion of the North Island and in Nelson,, which districts account for from 15 to 30 per cent of the total. Auckland itself experiences less than 1 per cent of New Zealand tremors. Hawke's Bay and Wellington The most violent earthquakes had been experienced in the Hawke's Bay and Wellington provinces, and over the northern portion of the South Island from Kaikoura northward. The epicentres of the earthquakes which affected the Dominion were all grouped in the region lying between Samoa. New Caledonia and the East Cape. In the centre of this region some of the most deep-seated earthquakes in the Pacific occurred, from 300 to 400 miles deep. The possibilitv that we were living in a fool's paradise, and that the gravity of the earthquake problem was rot sufficiently appreciated in this country, were stressed by Dr. L. Bastings in a subsequent paper. Dr. Bastings urged that our model earthquake building by-laws were far from satisfactory and that scientific consideration should be given to the type of subsoil upon which buildings were erected, as the nature of this vitally affected the safety of the building in a severe tremor.

"Most people believe that although we experience some earthquakes here, Japan is a far more dangerous place to live in," added Dr. Bastings. "As a matter of fact New Zealand experiences more violent earthquakes for its area than does Japan."