« السابقةمتابعة »
inner side, the top of the moraine is 30 or 40 feet above the level of the clear ice of the glacier.
The upper part of this moraine comes down nearly straight from the point B. The north branch glacier being, as was before noticed, considerably higher than the eastern, the moraine slopes down from the level of the former to that of the latter, forming a deep angular depression under the point B, (when it meets the foot of the north moraine of the east glacier ;) that gradually diminishes in depth up to the top of this glacier, which is here entirely covered with debris,, the moraines of its two sides being scattered all over it, for some distance above its union with the north or main branch. The appearance produced by this is that the northern branch runs over the eastern, or that the latter runs into the side of the former and is absorbed by it.
The eastern tributary brings down with it moraines which require no particular remark, beyond that already made, viz. that they spread over the whole of its breadth at its extremity.
Besides these lateral moraines, is a medial one, which, similar to several described by Professor Forbes, is first seen as a dirty stripe among the white ice cliffs of the fall at the head of the north glacier. As it comes down the level ice it gradually begins to assume the decided appearance of a moraine, and increasing by degrees at last becomes very large. It continues in a well defined form for some short distance beyond where the western moraine is dispersed ; but there it also is scattered over the ice, and the two become blended together and ultimately extend to meet the debris which is similarly dispersed by the eastern moraine from the opposite side of the glacier.
The whole of the moraines in the middle of the length of the glacier, where it is most regular, are very considerably raised above the general surface of the ice, which in some parts is, I should think, as much as 100 feet below the tops of the western and medial moraines. It is not to be supposed that this great elevation is caused to any considerable extent by the mere mass of rocks and rubbish collected in the moraine; it results from the ice below the mass being protected by it from external melting influences, which constantly depress the level of the clear ice beyond the moraine. On the very tops of the moraines pure ice was often seen hardly covered by the stones. The protection given to the ice by the great lateral moraines, raises
the sides of the glacier so much that a very considerable hollow is caused in its middle, which is a striking feature in the first appearance of its lower extremity.
The ice of which the glacier is composed agrees most exactly in its nature with the Alpine Glacier ice as described by Professor Forbes. It is perfectly pure and clear, but where seen in considerable masses stripes of a darker and lighter bluish green are distinctly visible. It is composed of bands of ice containing small air bubbles, alternating with others quite free from them. In many places the surface presents a striated appearance, arising from the different degrees of compactness of these differently colored bands, and their consequently different rates of melting.
The direction of these colored veins as seen in crevasses, or in the striated surfaces of the ice, follow laws exactly similar to those observed in the Alps. The dip was most distinctly inwards, i. e. towards the longitudinal axis, and upwards, i. e. towards the origin of the glacier, in every part; the stratification being more perpendicular near the head, and more nearly horizontal in the lower parts. The direction of the strata in plan, was also very clearly marked in many parts of the ice, and was plainly in curves, having their branches nearly parallel to the sides of the glacier, and their apices directed downwards; the curvature in the centre not being at all sudden. I no where could perceive "dirt bands."
The crevasses (perhaps owing to my visit having been made somewhat early in the summer) were much less numerous and terrific than I had expected. Although considerable detours were at times necessary in crossing them, I remember no place that I thought dangerous or difficult to pass. They are developed across the direction of the glacier's length along both of its sides, commencing from the small tributary on the west side, and from the union of the eastern glacier on the other; and continuing almost to the end, those on the west being, I think the largest. They are generally wider towards the edges of the glacier, closing up as they approach the centre. They are nearly vertical, and are directed from the sides upwards, or towards the head. of the glacier, those on the west bearing nearly E. and W., those on the east bearing nearly N. and S., thus forming angles of about 45° with the axis of the glacier.
Many pools of water (the Baignoirs of the Alps) were seen on the surface of the ice; some of the largest were said by our guides, who are in the habit of visiting the glacier, to be found in the same place every year. The clear surface of the ice everywhere assumes a more or less undulating form, from the action of the water that drains from it as it melts; and the small streams, into which the drainage collects, end, as in the glacier of the Alps, by falling into some of the crevasses. The remains of the last winter's snow was hardly perceptible on any part of the glacier.
The occurrence of stones standing up on bases of ice (Glacier Tables) above the general surface of the glacier, is common, but all that I saw were small. I also observed what appeared to be imperfect glacier cones, or the remains of them, but these also were small.
The ice of the glacier coming into direct contact with the cliff below the point A, I was enabled to examine the effect produced upon the rocks; I found it covered with grooves or scratches, sloping in about the same direction as the surface of the ice at the spot. These grooves extend to 20 or 30 feet above the present level of the glacier. I also observed, that almost everywhere a space was left between the rock and ice, the latter appearing to shrink from contact with the former. This was of course the effect of the heat of the rock melting the ice. I regret that an attempt that I made to measure the actual motion of this glacier proved ineffectual, owing to circumstances which it is not necessary to detail.
The valley of the Kuphinee, for a mile or two below the end of the glacier, has much the same general character as that of the Piudur, but is more rugged and desolate in appearace. A fine peak of pure snow (probably Nunda Kot, or No.15) is seen from below the glacier, but is lost sight of behind an intermediate point, on a nearer approach.
The direction of the glacier (fig. 4) is almost due N. and South, and the whole breadth of the valley, in its upper part, about & mile, is occupied by it. It commences about 2 miles above the river source, in a very precipitous fall of ice. We went up about 200 feet of the lower part of this, much beyond which it would probably have been impossible to ascend owing to the excessive steepness alone. A cliff of ice about 60 feet or 70 feet high rose immediately above the point which we reached. The ice was perfect, with the ribbon structure quite visible; the bands
were very highly inclined, and I think farther apart than in the lower parts of the glacier. The direction of the structural lines was in no degree parallel to the sides of the glacier, but much more nearly perpendicular to them. The precise contrary of this was observed by Professor Forbes under apparently similar circumstances, in the glacier du Taléfre in the Alps.
From the foot of the fall, the surface of the glacier was on the whole very even, though its slope downwards was very considerable. It still had remaining on its upper half a good deal of unmelted snow, which was disagreeable to walk over, as it was seldom strong enough to make us indifferent to what was under it.
The main glacier is joined by two small tributaries on the east, and by one on the west; all are highly inclined and bring down considerable quantities of debris. The moraines are altogether confined to the sides of the glacier, though many small stones are scattered over every part of the ice. Here, as in the glacier of the Pindur, the protection given by the moraines to the ice on the sides raises them greatly, and leaves a deep hollow in the middle of the glacier at its end. The crevasses here also are most strongly marked near the sides, and are inclined at an angle of about 45° from the longitudinal axis, downwards. The structure of the ice is in all respects precisely as was seen in the Pindur Glacier. I am unable to offer any decided opinion as to whether these glaciers have ever varied considerably from their present limits. During the very short period of my visit to these regions, I saw no direct evidence of it. The shepherds who take their flocks to the pastures in the valleys near the glaciers during the summer months, (for there are no fixed habitations within 14 or 15 miles of them,) have no idea of any motion in the glacier, but say that they suppose the ends of them to be gradually receding. Their statements are however of a very vague nature, and as far as I could judge, are founded on their views of what ought to be rather than of what really is. Some very decided change in the state of things is however certainly indicated by the long plateaus, which I before mentioned, running for a mile or two below the present terminations of both glaciers, nearly parallel to the rivers, but several hundred feet above them. I consider it to be impossible, that these level banks above the rivers have been caused by deposits from the ravines in the sides of the
valleys, for such deposits would have had very irregular surfaces; and indeed their present effect in destroying the regularity of the plateaus is every where visible. Had the same appearance been noticed in any other part of the river's course, it would at once have been attributed to the action of the water at some former period; and it would have been supposed, that the bed had afterwards been excavated to its present depth. If this was the case, the glaciers while the plateau was forming, must either have terminated considerably higher up the valleys, or have stood altogether at a much higher level; in either of these ways the water could have been delivered at a level sufficiently high to form the plateau. But it may admit of doubt, whether the quantity of water in the rivers, as they are at present, is sufficient to account for such an extent of level deposit, or for such a depth of erosion of their beds; for at this great elevation they are not subject to those violent floods that occur lower down; for nearly half the year too they must be almost inert.
The only other way that occurs to me of accounting for the appearance, is that it has been occasioned by an extension of the glacier, and that the level top of the plateau shows the limit to which the tops of the moraines reached, as the glacier gradually receded.. From the very cursory nature of my examination of the matter however I am unable to do more than point out the fact, and what possibly may have caused it.
There is another circumstance relating to these rivers which is also worthy of notice, namely, that in the upper 2 or 3 miles of their course their fall is considerably less than in the 2 or 3 miles immediately succeeding those. Thus in the Kuphinee, the average fall in the first 3 miles is about 400 feet, in the next 4 miles about 650 feet per mile; but as the average is only about 160 feet for the next 8 miles, it is highly probable that the fall in the 4th and 5th miles will be considerably greater than in the 6th and 7th. I therefore infer that it is quite possible that the fall in the 4th and 5th miles may be as much as 800 feet per mile, or even more; which the appearance of the rivers would fully justify.
Smaller extensions of the glacier of the Pindur were visible in many places. They were marked by mounds of a rounded form, covered with grass, projecting from the modern moraines in a curved direction. concave to the glacier. I did not remark them at the Kuphinee.