
Fissures, Landslips, etc.
These were formed chiefly in the valleys of the Hope and Waiau-ua Rivers. On the Hanmer River there were a few small cracks near the edge of the terraces, and a few others on an island in the bed of the Percival: all these appear to

have been filled up again before November. Small landslips occurred in the cutting leading to the bridge over the Waiauua, and two larger ones at the approach to the ferry. Up the Waiau-ua no fissures are reported until opposite the Grantham River, where there are some cracks 4in. or 6in. wide. From here, along the south side of the river, they get more and more abundant to Hopefield and Glynn Wye, but were seldom more than a foot in breadth, the larger ones being generally near the river. On the flat of Shingle Creek there were several fissures 4in. to 6in. wide. A large fissure was reported at the back of the house at Hopefield, and two circular holes about 4ft. in diameter and several feet deep are said to have been formed near Glynn Wye. Near this place fissures were very numerous in the terraces, some being more than a foot wide. Up the Hope they were still larger, some being more than 2ft. broad and several feet deep. Wire fences on the terraces were moved in places from 5ft. to 8½ft. horizontally. All these fissures were in alluvial deposits, and were more or less parallel to the valley of the Hope and Waiau-ua Rivers. Above the junction of the Boyle with the Hope the fissures get smaller and less numerous and more confined to the edge of the terraces, but there are numerous landslips on the sides of the mountains. Beyond Kiwi Creek no fissures have been noticed in the valley of the Hope, but some continue up the alluvium of Kiwi Creek. None are reported in the valley of the Boyle, and none in the Waiau-ua above Hopefield. As a glance at the map will show, all these fissures are confined to the alluvial deposits; none have been detected in solid rock.
At Tekoa Station, on the Mandamus River, numerous and large blocks of rock fell from the cliffs, making a great noise.
In the Bealey several landslips occurred, and in the Otira Gorge part of the road slipped down. At the accommodation-house at the entrance to the Otira Gorge the shock was felt very severely. Stones and rocks rolled down the mountainside in great numbers, striking each other and leaving long trains of fire behind them—a phenomenon which has been observed before in landslips. A large fissure was formed in Kelly's Creek, but I have not been able to obtain any particulars about it.
A miner from the Totara Flat District, between Greymouth and Reefton, reports that a number of trees on both sides of his claim were thrown down; and this was probably due to slips. A shepherd who was in Jones's hut, in the Upper Hope, also reported that dead branches were shaken from the trees, and it appears that many dead trees were also broken off about 10ft. from the ground, some at least a foot in diameter. In some places near here green trees 25ft. to 30ft. in height have been torn up by the roots; and this was probably due to slips.

None of the hot springs were permanently altered, although those on Hanmer Plains were much agitated, became muddy, and emitted more gas, but with no extra flow of water. By the 5th September they were merely discoloured, and they gradually got quite clear again. Sulphuretted hydrogen escaped from the ground in many places near the hot springs; and it was reported that it escaped from other places on the plain, but there is no evidence of this. A small opening was made close to the swimming-bath, which spouted out mud and gas, with very little water, for the three days that the ground was in constant movement.
All these phenomena appear to me to be secondary effects of the earthquake—that is, they were not the cause of the shock, but were produced by the reaction of the earth-wave in its propagation through the earth. Fissures which are more or less parallel to some superficial feature of the surface must almost certainly be themselves superficial; and fissures which are confined to alluvial deposits must almost certainly have originated in those deposits. They can, I think, all be explained by the principles laid down by Oldham and Mallet in their paper on the earthquake in Cachar of 1869.*
[Footnote] * “Quarterly Journal of the Geological Society of London,” vol. xxviii., p. 255.
