'QUAKE EFFECTS.

Star (Christchurch), Volume LXIV, Issue 783, 8 June 1933, Page 4

'QUAKE EFFECTS.

Interesting Paper by Professor Speight. The physical effects upon the ex* trenie north of Osnterburv of the Arthur's Pass earthquake which occurred , on March 9, 1929, were detailed in an j interesting manner by Professor R. Speight in a paper which he read at a meeting of the Philosophical Institute of Canterbury last evening. The paper was based on investigations of the earthquake area made bv Professor Speight during a visit in the earlv part of this year. Professor Speight said that the fact that an earthquake had occurred in a region where shocks had previously been unknown showed that earthquakes might reasonably be expected to arise in the future in areas which were not now considered to be dangerous. “ In my opinion the epicentral area is located to the east of Arthur’s Pass, and i the belt of country where the disturb- j ance was greatest extends in an E.N.E. direction through the head of the Poulter River and on into the upper valley of the south branch of the Hurunui River,” said Professor Speight. “ That is, the line of disturbance is probably a south-westerly extension of the seismic area near Hanmer Plains and Glen Wye, which has been responsible for the majority of the several shocks, with the exception of the Murchison and Cheviot earthquakes, felt in the North Canterbury area.” South Hurunui. Professor Speight said that, with the object of seeing what the district would yield, excursions had been made into the various valleys of the area likely to be affected. He had begun with | the area which promised the most data, the south branch of the Hurunui, The evidence of earthquake action ; was definite along both sides of the reach of the river, said Professor : Speight, slips of large size being com- ’ mon, especially towards the upper part. ' Some of these slips were comparable ' with those in the Murchison area. “It is remarkable that the belt where : slips occur is somewhat narrow, never ; much more than three miles wide and ‘ usually less,” said Professor Speight. ' “I am informed on good authority that ] such slips do not occur on the northern ■side of the Crawford Range, where 1 similar steep slopes lead down to the ] north branch of the Hurunui. The evidence therefore suggests disturbance on \ a continuation of the Hanmer Plains— Glen Wye line and its extension, to- [ ward.s the south-west into country not • suspected previously of being un- ! stable.”

At the head of the Poulter Valley, , 1 said Professor Speight, effects similar | to those in the south branch area also ‘ existed. The Minchin Valiev showed interesting physical features of earthquake origin, and there were a few small slips in the valleys of the Bealev and the Otira, which indicated a fall-ing-off in intensity of the disturbance in that direction. Professor Speight concluded his paper by detailing the information whiefi had been gained from his investigations. He said that they showed that the earthquake had an intensity approaching if not equalling that of the Murchison earthquake, and therefore it probably had an intensity of nine on the Rossi-Forel scale in the area of maximum disturbance. Papers were also read on the following subjects: ‘‘The Small-Leaved Pittosporums of New Zealand” (Mr R M. Laing), ‘‘The Egg of the Long-Tail-ed Cuckoo,” and ‘‘Some Observations on the Habits of the Short-tailed Bat.” both by the president. Mr E. F. Stead, j