THE ERUPTION OF RUAPEHU

Wanganui Chronicle, Volume LXXXI, Issue 18965, 17 March 1924, Page 9

THE ERUPTION OF RUAPEHU

ON MARCH 10, 1895. (By Geo. Cred Allen). Some of those who read the above heading may exclaim, “What! we never heard of that before!” Quite likely; because the Government of that day did it’s level best to suppress all mention of if. Why? Because, if it became generally known, intending settlers might be scared away. Three men from the neighbourhood went up to the snowfield which covers the summit of Ruapehu, on the third day after the eruption began, and, T.n their return to Karioi, said they could not see the water of the crater-lake because of the clouds of sulphurous heated vapour coming up from it. All three told me, separately, that lava rocks were being thrown out in a north-east-erly direction for about three miles. These men were David Sutherland, John Craig, jnr., and John Chase. Mr Sutherland was head shepherd of Mr Studholme’s run, Mr Craig was a settler near Karioi, and Mr Chase an intelligent, half-caste lining at Raetihi. About a fortnight after the beginning of the eruption, a young assistantsurveyor was sent by the Government to Ruapehu, evidently with instructions as to what he was not to see. His report began, “I was aware before ascending the -mountain that the story about rocks being ejected was untrue.” (I quote from memory, and these are probably not the exact words). I was living at the time on the left bank of the Wangaehu, 6 miles above Mangamahu, and on the morning of Sunday, March 10, went down to the church service at Mangamahu. Mr Craig senr., was at the service, and after it, he and I started up-river. Directly we saw the river we exclaimed about its rapid-rise and turbid condition, for the weather was quite fine. He was going on to his land near Karioi, and I parted from him at my gate seven miles above Mangamahu. At the door my daughter met me exclaiming “Oh, father! Ruapehu is in eruption, and you can see it from tho ridge above the dam.” I rode up to the ridge and saw a magnificent sight. A column of white vapour was rising vertically from the south end of the mountain to a height of about 6,000 feet, at which height it was caught by a light westerly breeze and rolled away to the eastward in great white clouds. The vapour did not show for about I,oooft. above the mountain, no doubt because tho heat from the crater was so great that the steam did not condense till that distance from it. thing may be seen at the spout of a boiling kettle. I resolved at once to visit the mountain as soon as possible, and I wrote to Mr Martin, photographer and Messrs Randal, builders, asking them to join me in the trip. (I asked some otners, but tjiey were unable or unwilling io coma). The weather became verji bad,' there was almost constant rain, and the roads both above and below Mangamahu wore blocked by slips, so that we did not get away from my house till the middle of April. We camped on ■the third night on tho Mamoenui stream, in the Kaimanawa mountains, about a mile east of tho 12th mile post on the Karioi-Tokaanu Road. The weather continued bad, and the Messrs Randall went away for three davs to visit friends near Raetihi.

There came a fine day and Mr Martin and I made a start for the mountain. We rode to the head of the Manga-toetoe-nui stream , (about 7,000 feet) and tethered our horses.

Mr Martin had insisted on wearing tt ?® vour * te Pair of hobnailed boots which I had warned him would cause him to slip on any hard ice, and in taking his big camera which weighed with its case, about 151bs, the result was that he spent about as much time lying on the ice, as walking. On one narrow ledge he fell backward on the camera, with his legs hanging over the edge of a precipice. I managed to get him up with great risk to both. So much time had been lost by his frequent falls that about 8,500 feet, I said we must go back as soon as we had eaten some lunch; this was about 4 p.m.

We loft the impediment on a ledge and got back to (he horses just before dark. When we arrived at tho road, ' we simultaneously exclaimed, “Thank God!”

Two days after the partial ascent fe the erater of Mr Martin and myself, the Messrs Randall retitrned, and on the next morning we breakfasted by candlelight, got the horses in, and made another start. We arrived at the source of the Manga-toetoe-nui, and there again tethered our horses. Mr Randal, being somewhat lame, returned to tho eamp. There being now a considerable depth of snow above 6,000 feet, Mr Martin had no difficulty in keeping on his legs; and wo got on well; and, before noon

attained the place where the impediments had been left on the previous day. We ate our lunch, and were about to start for the crater-lip when a snow storm came on, and we could not see fifty yards away. As it appeared likely to continue, I said that I thought we must not risk going further, as, though we could probably get to the summit in a couple of hours, we might not be able to find our way back to the horses, as the foiling snow would fill our footmarks. Of course this was very disappointing, as we had considerably exceeded the time we could reasonably spare. I said that if Mr Martin would leave the camera, etc., here, I would come up with him again on the first fine day. However, ho thought it best to give up; and so we went back to the horse camp where we found very little snow had fallen.

It was still early—about 2 p.m.—so we determined that, instead of taking a bee-line eastward to our camp, we would make a detour northeastward to where the ejected rocks were said to have been thrown. The descent was easy to the 3,000 ft. general level of the plateau on which Ruapehu stands. The country consisted of easy sloping ridges and galleys formed of volcanic ashes. Both in the gulleys and on the ridges there were hundreds of lava boulders, of sizes varying from that of a ten by ten foot room, down to that of a chest of drawers. Most of these were covered with mosses and lichens. But on to some of them had fallen blocks of red or black 'ava which had smashed them and themselves to junks of various sizes. These were spread in all directions over a circle of 40 or 50 feet radius. The difference between the old weatherworn boulders and the new fall len blocks of lava was convincing. We consulted on the spot whether the smashing of the rocks could be accounted for in any other way than that the clean ones had been cast upon the weatherworn ones by the recent eruption; and we decided that the positive statement of Sutherland, Craig, and Chase must be accepted in preference to the negative evidence of the assist-ant-surveyor.

We brought away speciments of the ancient rocks, and of the newly ejected ones, and got back to camp to cat the good supper Mr Randal had prepared. We started for our tomes next day, fairly satisfied with the result of our twenty-three days outing, of which only five were rainless. Although Mr Martin was disappointed at not being able to get photos of the crater-lake, he got many other good views of the neighbourhood, some of which I still possess. As to the probability of danger from future eruptions of Ruapehu, I take a sanguine view.

The eruption of March 10, 1895, was the first within the memory of man. I believe I am right in saying that the Maoris have no tradition of any eruption of Ruapehu, though Ngati-tu-wha-retoa have lived on the foot-slopes of the Tongariro group for ages. So long as Auruhdfe (vulgo Ngauruhoe) continues to act as a perennial safety-valve, there is little risk of Ruapehu again “busting-up.” But if it did, there is every probability that, the ejecta would be thrown in a north-eastgrly direction, in which case they would fall clear of any occupied land. Probably they would fall westward of the Waiouru-Tokaauu road. I have no map of the Touguriro group here, but I think it is about 25 miles from the Ohakune end on the south, to the Roto-a-Ira (Lake of Ira) end on the north. The width of the group is about fifteen miles from Waimarine on the west, ,towards the Kaimanawa range on the- east. Ruapehu is forest-clad up to 4,000 feet on the south and west, and has some forest patches on the south-east. Auruhoe and the rest of the Tongariro group have only patches on the east and west sides, but for the most part are bare except of tussock grass.

I infer from this that the tendency of ejections is from south-west to northeast; and if so, that settlements on the Ohakune, Raetihi, and Waimhriuo sides are safe. The land on the east foot of Ruapehu, and the plain eastward of it is a sandy desert called Rangipo. So much of the supposed useless country about Taupo and Murimotoe has been reclaimed that it is not wise to say that any of this country is irreclaimable; but thousands of acres of this Rangipo desert have not even tussock grass on them.

The crater-lake occupies the southern hall of the plateau at the summit of .Ruapehu. The northern half is no doubt also a crater, now inactive and full of snow, practically flat on the surface. The lake varies in size from time to time according to the seasons, on account of the encroachments, or withdrawals, of the ice-cliffs on the western end. Mr Archibald Willis and my son Frank and I, estimated it at about a quarter of a mile from west to east,

and half that length from north to south. The water was partly covered with a yellow sulphur-scum, and was tepid, which coused constant undermining of the ice-cliffs at the western end, and the frequent fall of great blocks of ice. But there is plenty of evidence that the lake had been frozen over, and boiling, at various times before the eruption of March 10, 1894, which occurred a year and two days after our visit.

Besides the rocks which were ejected, vast quantities of liquid mud were thrown out. Most of this fell into the 'head-waters of the Wangaehu Rivetcausing it to become a mere sludgechannel for the whole of its course to the sea, 117 miles. My abode was on the left bank of the river 70 miles down. For the first two or three days, the usual blue coloured water was replaced by liquid mud of the consistency of thick porridge. The roar of the rapids was rcpleced by sounds resembling the flop, flop, of simmering porridge. By the end of the week the river was bringing down what looked like thin cream, and after a few days more it resumed its usual pale blue tint.

Besides what mud was thrown into the Wangaehu, sufficient was ejectejj into the head waters of the Tongariro (commonly called the Upper Waikato) to discolour it right down to Lake Taupo; and into the Manga-nui-a-Te Ao to discolour it down to the Wanganui. , The Wangaehu had been described as ‘‘The Greatest Mineral River in the World.” After the eruption its water became so clear that whitebait, which had never been seen in it before were found forty miles up. Eels had never been seen in it before the eruption, but were known to come tip when the river was flooded during their breeding-time. A few years after the eruption eels were caught in the Wangaehu six miles above Mangamahu. I don’t know whether the river has returned to its qualification as ‘‘The Greatest Mineral River in the World.”