OLD FAULT LINE

Wairarapa Times-Age, 29 June 1942, Page 4

OLD FAULT LINE

EPICENTRE OF EARTHQUAKE FOUR MILES FROM MASTERTON. WELL OVER THREE HUNDRED SHAKES RECORDED. (By Telegraph—Press Association.) WELLINGTON, This Day. While final placing of the epicentre of Wednesday night’s earthquake must of necessity await the receipt and correlation of reports from many parts of the Dominion, the Seismological Branch of the Department of Scientific and Industrial Research has provisionally placed it as 56 miles away from Wellington in direct line, about four miles due north of Masterton. This is on one of the old fault lines lying to the east of the 'Tararua and Ruahine Ranges. The records of the Wellington seismological station show that up to 9 а. yesterday there had been 350 after-quakes. Between the time of the earthquake on Wednesday night, and 7 a.m. the following morning, there were nearly 200 shakes recorded, while in the following 26 hours (to 9 a.m. Friday), there were another 94. The 24 hours ending 9 a.m. Saturday recorded 34, and to the same time yesterday another 23 were shown on the recording chart.The seismological authorities have tentatively estimated the force of the earthquake in the various areas as follows:— Masterton and district 9, Palmerston North 8, Wellington 7|, Wanganui to Porangahau line 71, New Plymouth to Waipawa line 6, Blenheim б. The Wellington and Christchurch records agree in suggesting that the focus of the disturbance was not deepseated. The intensity figures of the earthquake quoted are those of the Rossi-FOrel scale, which is a schedule based on the degree to which the quake is felt by inhabitants of the area, and on the type and degree of the

damage caused. The maximum strength on the scale is 10, which applies to a major disaster, with buildings ruined, disturbance of earth strata, and fissures opening in the ground. An earthquake recorded on the Wellington seismograph at 1.15 p.m. on Saturday appears to have occurred in a different area altogether, approximately 300 miles away.. Preliminary investigation of the record suggests that it was of fair force and deep focus. An observer in Palmerston North reports feeling a tremor of about 10 seconds’ duration with a swaying movement about that time. The Seismological Branch of the Department of Scientific Research would welcome authenticated details of the lights reported to have been seen by observers who were looking outf over Cook Strait.