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.
CHAPTER II
THE ROUTE TO THE MOUNT COOK DISTRICT
A short description of the route to the Mount Cook district, and of the topographical features of the Mueller, Hooker, and Tasman Valleys
From Timaru on the east coast the traveller may comfortably reach the glaciers of Aorangi in a two days’ journey.