IIL— GEOLOGY. 



Art. XXXII. — Tlie Earthquake in the Avmri. 

 By Professor Hutton. 



[Read before the Pliilosophical Institute of Canterbury, 6th September, 



1S8S.I * 



Plates XV.-XVII. 

 The earthquake that took place on Saturday, the 1st Septem- 

 ber, 1888, was felt from Invercargill in the south to New Ply- 

 mouth and Masterton in the north, a distance of about six 

 hundred miles, but was most severe in the neighbourhood of 

 the Hanmer Plains, which are nearer to the northern limit of 

 the disturbed area than to its southern limit by about fifty 

 miles. The shock commenced soon after 4 a.m., with a rum- 

 bling noise and slight shakes for a second or two, followed by 

 the main shock, lasting from forty to sixty seconds, or even 

 more in some places. Judging from my own feelings at Christ- 

 church, I should say that the shock was a backward-and-for- 

 ward oscillation that began gradually and as gradually died 

 away after about forty-five seconds' duration, and that it was 

 not accompanied by any sharp jerks. It was followed within 

 the next quarter of an hour by two much smaller shocks, 

 while other slight ones occurred continual!}- until 5 or 6 a.m., 

 these slighter shocks being only felt in the x\muri, at Boat- 

 man's, Eeefton, and Westport. All Saturday, Sunday, and 

 Monday the gi'ound at the Hanmer Plains was quivering ; 

 with smarter shocks, felt on the west coast and at Christ- 

 church, at about 3.55 a.m. and 4.25 p.m. on Saturday, at 11.15 

 a.m. on Sunday, and at 8'15 a.m. on Monday. At Westport 

 small earthquakes occurred almost every day for a fortnight ; 

 at Reefton every day for nine days ; while in the Hanmer 

 Plains they were tolerably frequent up to the end of the 

 month, with heavier shocks, felt on the west coast and at 

 Christchurch, on the 9th and 28th September, and again on 

 the 12th October. A slight shock was felt in the Amuri on 

 the 28th October, and another at about 11 a.m. on the 13th 



* A rough draft of this paper was read on 6th September, 1888, but 

 it has been added to and revised up to 20tli November, 1888. 



