Te Ika a Maui, or New Zealand and its Inhabitants
Appendix F. — Mem. on the Earthquake in the Islands of New Zealand, January 23, 1855
Mem. on the Earthquake in the Islands of New Zealand, January 23, 1855.
This table was taken from Dr. Shortland's “New Zealand.”
Number of rainy days at Wellington in 10 months, 133.
Number of days on which the wind was from the N. or N.W., 202; ditto, ditto, from S. or S.E., 141.
The shock was of the greatest violence in the narrowest part of Cook's Straits, a few miles to the S. E. of Port Nicholson; but it was felt over the whole of the islands and by ships at sea 150 miles away from the coast; the whole extent of the area over which the convulsion was felt must have been 360,000 square miles.page 472
Its effects were most violent in the immediate vicinity of Wellington, where a tract of land of 4,600 square miles in extent was elevated to a height varying from one to nine feet, the greatest elevation being a rang of hills called the Rimutaka (a spur from the Tararua mountains), which terminates abruptly at the sea coast in Cook's Straits.
This range, which appears to have been in the direct line of the subterranean action, was elevated nine feet, while the whole country as far as Wai-nui, about two miles northward of the foot of the road leading down the Pari-pari, was elevated with it, though the elevation at the last named point was on the sea coast very slight. On the Eastern side of the range is the valley of the Wairarapa, the centre of which is occupied by a lake. This valley and plain remain on the same level as before, the range of hills having gone up alone, forming a perpendicular precipice of nine feet in height, which has been traced to a distance of ninety miles inland.
The valley of the Wai-rau, on the middle island (which appears to have formed part of a continuous basin with the Wairarapa), together with parts of the adjoining coast, subsided, during the shock, about five feet; so that now the tide flows eight miles further into the Wai-rau river than it formerly did.
The harbour of Port Nicholson, together with the valley of the Hutt, is elevated from four to five feet, the greater elevation being on the eastern side of the harbour, and the lesser on the western.
A rock, known as the “Ballet Rock,” a short distance from one of the points of Evans's Bay, which was formerly two feet under water at the lowest tides, and over which was placed a buoy to mark its position, is now nearly three feet above the surface at low water.
Very little tide now enters the Hutt river, in consequenee of the elevation.
The Rimutaka range was very much shaken in its elevation, and a great many large slips occurred, laying bare the western side as well as on the eastern.
In the lower part of the valley of the Hutt, numerous hillocks of sand were thrown up, forming cones, varying from two to four feet in height, and in many parts of the valley large fissures were formed, with partial subsidences in many places. In the plains of the Manamatu this was the case to a much greater degree.
In many places soft mud and slime were ejected, but this appeared more a mechanical effect than anything else, the liquid mud having pre-existed and been forced out at fissures formed during the vibration by superincumbent masses of more solid material.
Upon the whole the province of Wellington will gain considerable advantage from the earthquake:—
1st. Large portions of land can be easily reclaimed from the harbour for the extension of the town.
2d. The main road to the Hutt and the interior formerly suffered occasionally from the action of the waves during high winds, and many parts had to be retained by a sea-wall; now it will escape the damage of the one and the expense of the other, and the whole of that valuable valley will be rendered, if possible, more healthy from greater facility of drainage arising from the elevation.
3d. A much better coast road to the eastward is already formed for the temporary use of the colonists and the driving of cattle.
Edm. Robberts, Royal Engineers.