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The New Zealand Alps and their glaciers

It is unnecessary for me in these days of universal education and enlightenment to describe the geographical position of New Zealand, the ‘Britain of the South,’ and the future playground of Australasia.

Everyone knows that New Zealand consists of three islands, situate between the 34th and 47th degrees of south latitude, off the south-east coast of Australia. Reference to almost any handbook of the colony will furnish every information regarding settlement, population, government, climate, and so on, and I do not propose to dwell longer than is necessary on any general matters of this nature.

It is advisable, however, to describe in as brief and concise a manner as possible the general physical features of a country containing such varieties of scenery and climate, more especially those of the South Island (or Middle Island as it is sometimes called), where the High Alps and their wonderful glaciers are situated.

Speaking generally, the highest mountains of New Zealand may be said to run in a north-easterly direction from the southernmost point of the South Island through the whole country, like a vast backbone, to the north-eastern point of the North Island.

The main formation of the mountains dates back to Jurassic times, so that the geological structure may be said to be one of great antiquity.

Volcanic action has long since ceased throughout the South Island; but there are many active volcanoes in the North, where a perfect wonderland of hot-springs, solfataras, and silica terraces exists.

As a whole, the country is heavily timbered—more thickly on the western parts, where the greater rainfall occurs. This is notably the case in the South Island, where the hot and moisture laden winds from tropical regions are deprived by the Alpine chain of their aqueous vapour.

The Southern Alps proper may be said to extend over a distance of about one hundred miles of the middle part of the South Island, the chain being situated closer to the western than the eastern ocean. The slopes on the western side are the more precipitous, and are clothed with heavy timber and intersected by innumerable mountain torrents, fed in most cases by glaciers, some of which descend to within 600 feet of sea-level.

Ranges of outlying foot-hills occur on the eastern side, snow-covered in winter, amongst which many large glacier-fed rivers have cut their way, and meander over the plains (probably of entirely fluviatile formation) which slope gradually from the outer bases of the foot-hills to the eastern ocean.

The peaks of the Alps range in height from 7,000 to 12,350 feet above sea-level, the majority of those over 10,000 feet being contiguous to the culminating point in altitude—Aorangi—more popularly known as Mount Cook. Here also are found the largest glaciers.

The snow-line is a low one when compared with that of Alpine countries in the northern hemisphere and in relative latitudes. It would be difficult to compute its average altitude, but in parts where large glaciers and snow-fields exist it is even as low as 5,000 feet above sea-level.

By comparison with Switzerland, for instance, it may safely be said that the snow-line in New Zealand is from 2,000 to 3,000 feet lower; consequently we have the same Alpine conditions at a much lower level. Owing to this interesting fact, we find that the New Zealand glaciers attain far greater dimensions than those of Switzerland, although the peaks do not rise to such a height above sea-level.

In themselves, I believe the mountains compare favourably as to size or actual height above the valleys below them; Aorangi, for instance, rising for nearly 10,000 feet from the Hooker Glacier, and Mount Sefton 8,500 feet from the Mueller Glacier, whilst the western precipices of Mount Tasman (11,475 feet) are stupendous.

The enormous length attained in remote times by the New Zealand glaciers is evident on all hands at the lower parts of the valleys, the heads of which they now occupy; whilst the formation of nearly all the lakes in the South Island can be traced to the action of ice and the deposition of terminal moraines, prior to a period of retreat of the ice.

There is an interesting feature in the glaciers of this country peculiar to them; I refer to the deposition of singularly extensive moraines. The lower parts of the large glaciers on the eastern slopes are, in nearly every instance, completely covered with accumulated débris derived from the moraines. This is variously accounted for by the antiquity of the mountain chain, the slow rate of motion in the ice, and great denudation from rocks which are much jointed and offer but little resistance to the splitting powers of freezing infiltrated water.

The western glaciers I am not personally acquainted with, but I understand that they do not carry anything like the amount of moraine, and I imagine the cause of the disparity will be found in a faster motion of the ice, and (a yet more potent factor) in the dip of the strata of the rocks, which is from east to west, the broken faces being eastward and the slab-like faces westward.