The First Ascent of Ruapehu, North Island, New Zealand.
Ruapehu, with an altitude of 9,175 feet, is the highest mountain in the North Island of New Zealand, and is the southernmost of the three volcanoes Ruapehu, Ngauruhoe and Tongariro extending about 40 miles southwards of Lake Taupo; they are all practically extinct; Ruapehu sometimes throws up clouds of steam; Ngauruhoe, a cinder cone, sometimes ejects steam and scoria; while Tongariro, except for thermal springs, is practically quiescent.
The summit of Ruapehu was first reached by Mr. G. Beetham, M.H.R., and J. P. Maxwell, M.Inst.C.E., during February, 1879, from the southern end, when the great crater was first discovered.
During 1878, Mr. G. Beetham, accompanied by a young man, explored the Wangaehu Gorge of the mountain on the eastern side, but found that an ascent by that route appeared to be impracticable; and he decided to defer his attempt until the following year, by the southern spurs.
The mountain has extensive icefields and glaciers; and ancient moraines now covered with scrub and dwarf bush extending for long distances into the southern and western country indicating that the glaciers in former times were of much greater extent than they now are.
– 21 –
Very little was known of this part of the country when the ascent was made, as the only access to it was then by bridle tracks from the eastern coast; a day or two was therefore occupied by exploration before the ascent was attempted.
During this exploration, the upper margin of the Wangaehu Gorge was visited, disclosing a very magnificent spectacle. The River Wangaehu rises near the top of the gorge from the melting snow and icefields in and around the crater and which discharge at a lower level. The gorge appears to have been formed by the joint action of volcanic eruption and glaciers. The water is very strongly impregnated with acid and sulphur and is of a milky colour. These characteristics are, during hot summer weather, sometimes maintained until it reaches the sea. The early settlers on the west coast had a tradition that on one occasion a large body of ice reached the sea, having been expelled from this gorge by unusual thermal development.
In passing over the old lava streams on the way to the margin of this gorge, the explorers observed beehive-shaped hollow developments from six to eight feet high, obviously the result of bubbles formed by gases from the molten lava. These shells had split into pentagonal blocks during congealation.
The explorers pitched their camp on the upper margin of the dwarf bush covering the ancient side moraines of the mountain. The ascent from this on the selected route took nine hours following the scoria gullies formed by snow and rain, until the glacier was reached, this they crossed at the brow and followed up the western side moraine along the margin of the glacier until they got access to the great southern spur from the summit. When this summit was reached they found themselves on the lip of a great oval crater which they judged to be two or three miles in length. Immediately below them was an icefield some few acres in extent, with a circular pool of milky water in the middle; the surface of this water was many feet below that of the icefield, the walls of the pool were of ice. The waters of the pool broke out at a much lower level below the crater, and formed the source of the Wangaehu River.
The need to make the camp in daylight prevented further exploration. The descent to the camp occupied four and a half hours only. Various ascents from the northern side of the mountain have since been made, an easier route having since been found. Government surveyors who have been up during winter have found that the whole crater is then a great icefield with no appearance of a pool in any part of it, this latter development apparently being the result only of a long hot summer.
The dwarf birch bush on the lowest flanks of the mountain on the ancient moraines has a peculiarity. The moraines are composed mainly of huge blocks of lava. The trunks of the dwarf birch crawl along among the surfaces of the lava blocks, their branches only being vertical. It is interesting to know that amongst the remaining vestiges of Dartmoor oak forest in
– 22 –
Devonshire the oak trees growing among granite boulders and rocks formerly presented the same peculiarity, of horizontal creeping trunks and vertical branches springing therefrom.
J. P. Maxwell.
London,August 6th, 1925.
.jpg)