Hoqbbn. — Becent Earthquakes in New Zealand. 301 



Art. XLIV. — -Notes on some Recent Earthquakes in New Zealand. 

 By G. Hogben, M.A., F.G.S. 



[Read before the Wellington Philosophical Society, 24th September, 1913.] 



Inner New Zealand Region. 



(1.) 16th March, 1912. — A sharp shock. Epicentrum about sixteen 

 miles north-west of Westport.j 1 ' 



(2.) 26th May, 1912. — Felt at Stratford, New Plymouth, Auckland, 

 Thames, Morrinsville, Tauranga, Wangan.ui, Wellington. Maximum inten- 

 sity, observed at New Plymouth, VII -VIII on the Rossi-Forel scale. 

 Several chimneys fell at New Plymouth ; one chimney fell at Auckland. 

 Intensity at Hamilton, VI- VII, R.-F. scale. Double origin : (a.) 38° 28' 

 S., 173° 51' E., forty miles north by west of New Plymouth, about sixteen 

 miles from the origin of earthquake of 24th June, 1891 ; (b) near south 

 west end of Waiheke Island, at the entrance of the Firth of Thames. 



(3.) 22nd February, 1913.— Westport earthquake, VIII-IX, R.-F. scale. 

 Epicentral area, at least twenty miles long, running north-north-east ; 

 principal movement from a point about twenty-two miles west-south- 

 west from Westport, opposite Tauranga Bay. 



(1.) 16th April, 1913.— Sharp, IV-V, R.-F. scale. Origin near Lake 

 Manapouri. 



(5.) 12th July, 1913. — 'Sharp, near origin of earthquake of 24th June, 1891 . 



It will be noted that these five earthquakes (besides a number of slighter 

 shocks felt at Westport and some proceeding from an origin apparently 

 north-west of Cape Farewell) came from origins lying near a line parallel 

 to the general axis of New Zealand. Moreover, the origin of a very severe 

 earthquake on 7th September, 1910, observed at all the chief stations of 

 the world, was near the Kermadecs on a continuation of the same line. 

 Near the same line, to the south -south -west, in lat. 52° S., 153° E., occurred 

 also another world earthquake on 3rd February, 1910. 



Outer New Zealand Region. 



(6.) 12th April, 1913. — Felt all along the east coast, in the Wairarapa, 

 Wellington, and Manawatu districts. Probably proceeded from the well- 

 known region, 200 miles east-south-east of Wellington (between Wellington 

 and the Chatham Islands), which gave us the severe shock of 9th August, 

 1904. As in that shock also, the level at Wellington was slightly tilted 

 towards the west. This suggests a series of folding movements about axes 

 nearly parallel to the general axis. 



Further Notes on the Westport Earthquake of 22nd February, 



1913. 



Times. — Christchurch (Milne seismograph): Preliminary tremors (1), 

 1.09-1 ; long waves commence, 1.09-7 ; maximum, 1.10-1. Riverview 

 Observatory, Sydney (Wiechert horizontal pendulum) : P.t., 1.08-2 ; long 

 waves, 1.12-6 and 1.16-15. Westport: 1.08, or perhaps 1.07-5 (Morgan). 

 Nelson (galvanometer), 1.09. (All times are Greenwich mean civil time.) 



It is difficult to determine which times at Sydney and Christchurch 

 belong to the same phases (the instrument at Wellington was not working, 



