NEAR MASTERTON

Wairarapa Times-Age, 26 June 1942, Page 3

NEAR MASTERTON

EPICENTRE OF EARTHQUAKE DOMINION OBSERVATORY’S REPORT. MAJOR DISTURBANCE BELIEVED OVER. The Dominion Observatory reported last night that seismograph readings at Christchurch, combined with its own readings, confirmed that the epicentre of the big earthquake _on Wednesday night was in the neighbourhood of Masterton. The first shake as recorded at the Dominion Observatory was just before 8.15 p.m. This was the worst earthquake felt in Wellington for a considerable time. Its intensity was 4 to 5 on the Rossi-Forel scale, which divides earthquakes into 10 groups of progressive intensity 4 to 5 including shocks “felt generally by everyone; disturbance of movable objects; creaking of floors.” But the intensity of this shock like the bigger one which was to follow, varied considerably in different parts of the city and suburbs. In the Hutt Valley both the shocks were apparently felt more severely than in Wellington itself. After the first shake, which was felt for 15 to. 20 seconds, came a period of absolute quiescence, the seismographs not recording the slightest tremor. This was an unusual feature, surveying the disturbance as a whole. A second, or two before 11.17 p.m. the main shock came. It was of an intensity of 7 to 8 on the Rossi-Forel scale, 8 on the scale being defined as “strong shock; fall of chimneys, cracks in walls of buildings.” But, here again the intensity varied considerably according to locality. Judging by the records made by the seismographs, this shock could have been felt for from 60 to 90 seconds. Many people felt it for fully a minute, and oscillations continued to be recorded for a long time after they could be felt. In addition to the noise caused by creaking houses and overthrown objects, the earthquake was accompanied by loud subterranean rumblings. After-shocks continued throughout the night and on into yesterday morning, qnd the seismological tracings show that they were very numerous.

But the progressive decline of their frequency and intensity is. regarded as a reassuring sign, indicating that the major part of the disturbance is over. The strongest of the after-shocks, and the last of any intensity, was recorded at 1.12 a.m., being estimated as 4 on the Rossi-Forel scale.