THE SHYOK ICE-BARRIER IN 1931

CAPTAIN C. E. C. GREGORY

MY ORIGINAL intention was to spend some time shooting in the Hanle district of Ladakh and then go on to Phobrang and cross into Chinese Turkistan by way of the Aksai Chin. With this object I left Srinagar on the 12th April, and when passing through Leh arranged with Bishop Peter of the Moravian Mission to send my porters and supplies for the Changchenmo-Aksai-Chin crossing, to Phobrang. On arrival at the latter place I received word that my passport for Central Asia had not arrived, and it looked possible that I might not get one at all. I therefore went off to shoot round Dakpo Karpo and the Changchenmo; on my return again to Phobrang I learnt by wire that the passport had been despatched from Nanking on the 29th May and I judged that it should reach Leh by the 5th July at the latest.

I now decided to return to Leh and travel by the shorter and quicker route by the Karakoram pass. I left Leh on the 23rd June, having given instructions for the passport to be forwarded to me by special runner, and spent some time mapping the Chong Kumdan glacier and the Shyok lake. Having completed this work I pushed on to Daulat-Beg-oldi, close to the Karakoram pass, but after waiting some time for the passport, my supplies began to run short, and, though I tried to persuade my caravanbashi to go on to Suget for more, he refused to do so and I was forced to return. This short paper therefore is merely a brief summary of my observations of the Chong Kumdan glacier-dam*.

It was on the 28th June that I left Takshai, the last village in the Nubra valley. Up till that date no one had crossed the Saser pass that year and the inhabitants of Nubra stated that it was still deep in snow and unfit for pony-transport. I had three permanent porters with me and collected six more at Takshai (pay Re. l/-a day). In the Thulan-buti defile I met the first of the Yarkandi caravans. Their news was not very hopeful; they had stayed at Saser Brangsa, north of the pass, till their food was almost exhausted, and had then tried to force it, with the result that they had had to abandon their baggage on the pass after losing two ponies and three asses.

I therefore left my own animals at Skyangpo-che and moved up towards the pass with my coolies only, halting that evening at the first of the lakes. I intended to start at 5 A.M. the next morning, cross the pass and reach Saser Brangsa that day, but at midnight, when I looked out, the snow was frozen hard and the moon full, so that I felt it was an ideal opportunity to cross. I went over to the porters, but they were not for it, saying that it was too cold and that in their local boots they would get frostbitten, but that they would start at five. At five the next morning it was snowing hard and we were forced to remain there all day. It was again snowing at 5 A.M. on the 3rd July, but an hour later the sky looked better, the snow had stopped and the porters agreed to make a move. Fortunately for us the sun hardly came out all day and the eight miles to Saser Brangsa were covered in eight hours.

On the 4th July I moved the camp up the Shyok valley to the Kichik Kumdan glacier, from the terminal moraine of which I could see the snout of the Chong Kumdan glacier lying across the valley like a bar of silver. There was very little water in the Shyok, and at the Saser Brangsa ford it was only about a foot deep.

On the 5th I went up to the Chong Kumdan. The point from which the best view can be obtained is about a thousand feet above the main valley bottom on the right bank of the Shyok. From here the Shyok lake can be seen stretching away to the north, beyond the three miles of glittering ice-pinnacles of the Chong Kumdan glacier almost immediately below. The panorama published with this paper gives some idea of the magnificence of the spectacle.

The lake at that time was ten miles long and varied from a mile to a mile and a half wide. Later when I went round and camped at the north end of it, I found that its level was rising at a rate of from six to seven inches a day. Above the surface-level on the hillsides at the edge of the lake were to be seen previous marks caused by water-erosion. In July the lake was from thirty-five to forty feet below the highest erosion-mark* from which fact I concluded that by the beginning of the winter of 1931 the surface would be at its high-water level. As regards percolation through the ice-barrier, three hundred yards downstream of the snout of the glacier the Shyok river-bed was dry. On the 5th July there was very little water coming off the Chong Kumdan, and though on the 6th there was more, there was still less here than was issuing from the Kichik Kumdan glacier.

The Chong Kumdan glacier descends from a broad trough in the mountains. Standing at the snout it is up the Chong Kumdan valley and not up the main Shyok valley that one looks†. The Chong Kumdan glacier and lake, in fact, form the upper branches of a " Y ", the tail of which is the Shyok valley below the snout. Unless this is realized, the map, which shows a " T " lying on its side, is misleading. At the time of my visit the width of glacier against which the waters of the lake were resting was about 1500 yards, the same as that of the valley bottom immediately below the snout. The ice of Chong Kumdan, or left branch of the " Y ", extended for a distance of 1100 yards below the point where the eastern edge of the lake met the ice.

The height of the ice at the snout was about ninety feet; where it was holding up the lake it might be as much as two hundred. Here it was a mass of pinnacles and it was difficult to judge the height. These pinnacles extend for a distance of three miles up the glacier and are due, I think, to the effect of the warm dry wind blowing up the main valley. They and their attendant ice-walls make climbing on the glacier difficult and crampons, ice-axe and rope are essential. I did not come across any bad crevasses, but the surface was badly cracked, and there would have been danger of an accident with laden or inexperienced men. The height of the pinnacles was from sixty to eighty feet. Once the sun reached the glacier surface, stones and ice started to fall; for this reason it was unsafe to be on the glacier after eight o'clock.

A curious feature of the Chong Kumdan glacier was the complete absence of dead lateral moraine. The valley out of which the glacier emerges has steep cliffs on either side and the glacier ice reached right up to these cliffs. The terminal moraine consisted of a small pile of stones, out of all proportion to the size of the glacier. The channel cut in the ice by the escaping waters in 1929 could be clearly seen and acted as a central drain for the surface ablation of the glacier. Should the lake overtop the glacier, its waters would use this channel and probably open it up so rapidly that a flood would follow. If the barrier actually breaks, it seems to me probable that it will do so in August 1932, this being the month that it has usually burst before. With the water up to the high-water level and the old scar in the glacier, with the almost complete absence of percolation, I consider that the lake is almost certain to overtop the barrier or burst it in 1932.

Should anyone think of going up to the ice-barrier in 1932, I would suggest that, after halting at Saser Brangsa, they move up the right bank of the Shyok to just short of Kichik Kumdan, using porters only from Saser Brangsa onwards. The next camp should be pitched near the snout and the party should start the next morning very early, pass the two side glaciers on the right bank of the Chong Kumdan, and cross the main glacier just above where it is joined by the lake. Should there be a break, in all probability this route will be above it and will remain. On the north side of the glacier a camp could be pitched on the spur on the west edge of the lake, just above the point where the lake meets the ice. This would save the long detour by the Depsang plains. Also, the two metal boats left by Gunn in 1929 at the mouth of the Chip-chap have now been removed.

I ought perhaps to warn people against attempting to climb the cliffs on the left bank of the Shyok just below the glacier. Though it is possible to do so and to reach the lake by this route, the chimneys that have to be traversed form dangerous stone-shoots. I would also recommend that any party moving on the glacier itself should be clear of it by 8 A.M., when the sun may get on to it and render it dangerous from falling ice and stones.

 

Note by the Editor.

Thanks to the courtesy of Captain Gregory and Messrs. Ludlow and Gunn, we have now some forty photographs of this glacier, taken from various points during the last four years. Much as I should like to do so, it is not possible to publish all these, though a careful examination makes clear some very interesting conclusions. In addition to the photographs and accounts of these observers, we also have a report by Mr. P. C. Yisser of his observations in July 1930.

The photographs taken in 1928 and 1929 from below the snout are very similar. The larger series of 1929 show some definite features that led me then, in spite of Gunn's report, to doubt whether the glacier had begun to retreat, and I then foretold that the channel cut by the lake would heal during the winter of 1929-30, and that another lake would be impounded14. These features are very marked when the 1929 photographs are compared with Captain Gregory's beautiful series taken in 1931.

In 1929 the upstream photographs show a vertical, and in places an overhanging, dam face holding the lake. The ice at the edges of the lake showed cracks and the ice-pinnacles emerged almost directly from the water's edge. The ice itself showed intensely white in the photographs, and even from a distance little englacial or medial moraine could be observed. These features may be seen to some extent in the two photographs in the Himalayan Journal, vol. ii, opposite pages 38 and 46. A complete series of fourteen photographs by Ludlow emphasizes them.

In 1931 there was a marked change. The lateral pinnacles were much reduced in size and became more degenerate ; masses of medial moraine were being carried to the edge of the ice and were falling into the lake.

In 1929 the lake edge of the dam had a marked convex bulge into the lake, probably owing to pressure against the rock wall opposite. The 1931 dam showed a straight, almost a concave, edge to the lake.

Downstream of the glacier, the 1928 photographs show a protuberant tongue, possibly due to snout-spread, in the centre of the Shyok valley. There is little difference in 1929, both before and after the burst. The edges in both 1928 and 1929 were vertical (slightly more so in 1928 than after the burst in 1929, probably due to seasonal ablation in August). In 1931, as shown in the illustrations in this volume, not only the snout-tongue, but the whole snout-face was breaking up into detached ice-pinnacles very much interspersed with englacial and surface moraine. In pinnacled glaciers such as this, moraine-banks are only left as isolated terminal moraines when the ice-pinnacles are dead*. ' Retreat' is most irregular, and, as could be seen in the neighbourhood of the Kichik Kumdan glacier in 1928, much dead ice is left below the living snout.

If further proof were required that ' retreat' and degeneration has now set in, it is to be found in the pictures of 1929 and 1931 which give a longitudinal profile of the glacier surface. Ludlow's and Gunn's photographs of 1928 and 1929 show that of the portion of the glacier lying across the Shyok valley, the highest point lay then towards the left bank of the Shyok, which indicates that the ice had been forced up by pressure against the wall. The panorama looking up the Shyok across the glacier, published in the present volume, shows that the highest point in 1931 was where the glacier enters the Shyok valley. From here the height tailed off towards the left bank, indicating a relief from pressure. This panorama also shows very distinct signs of pinnacle degeneration, particularly towards both edges and the opposing wall.

In 1929 the waters of the lake cut a channel approximately five hundred feet wide. The channel apparently commenced from near the right or western shore of the lake, took a course towards the centre of the glacier and emerged near the left or eastern side of the Shyok valley. In July 1930 the Vissers reported that the channel had completely healed and that there was no sign of it, though traces of the burst were still to be seen below the snout. In the same month, in 1931, though there was still no percolation through the glacier and no water issuing from beneath the ice, the channel had again opened out and acted as a central drain for surface water from the glacier. These facts again point conclusively to a release from pressure.

Estimates of the height of the ice at the snout and of the depth of the water at the dam are difficult to compare. In the snout observations we do not know whether the observations were made at the same spot. Ludlow's estimate in 1928, from some distance away was, " at its snout it could hardly have been less than 200 feet high ". Gunn gives the height in August 1929 as " about 500 feet". Visser does not mention it, but in July 1931, Gregory gives it at about 90 feet. A few days before the burst in 1929 Gunn gives the depth of the lake at the dam as about four hundred feet; in July 1930, when the reformed lake had reached a length of three miles, Visser calculated the depth at the dam to be 133 feet; in July 1931, Gregory thought that it might be as much as 200 feet. Too much reliance must not be placed on these figures ; it is notoriously difficult to make such estimates. But even assuming that Ludlow was liberal, that Gunn was radical, and that Gregory was conservative, these figures do bear out the conclusions given above from examination of the ice-formation in the photographs.

The two points of human interest are : Will the dam burst catastrophically ? And if so, when ? The second question may be answered first. There can only be a catastrophe if the dam bursts when the river is at or near normal high summer-level. This is between mid- July and October, inclusive. Damage from scour and isolated accidents from drowning may occur at other periods, but villages and grazing should be above the flood level. The point is: Will the dam hold till then ? In my opinion, though there was no percolation in July last year, degeneration had set in to such an extent that in all probability there was a good deal of leakage before the winter. By October I believe the glacier may have been too degenerate for any substantial recuperation during the winter, and that spring and summer ablation in 1932 with normal periodic decline will relieve the lake of much of its water. It is an opinion that I hesitate to put forward, for observations of the little glaciers of other parts of the world are of no value for comparison. Of one thing I feel certain. I still maintain that after 1932, there will be no further danger of a block for over thirty years.

The above Note was sent to Captain Gregory, who comments as follows :

Now that I have had time to examine carefully the state of the glacier snout as shown in Gunn's photographs, I too think that degeneration has set in ; but at the same time, though I do not know very much about the subject, I shall be very astonished if so great a volume of water can be carried away by percolation. It may be of interest to mention the following facts which may affect the percolation question. In 1931 on the 7th and 8th July there was no percolation at the snout when I was there. On the 12th July I crossed the Shyok at Saser Brangsa ; the water was then knee-high as against about eight inches on the 4th July, say ten inches higher. On the 17th and 18th July I was at Yapchan when the lake was rising at the rate of six or seven inches a day. On the 22nd I again crossed the Shyok at Saser Brangsa ; the water was now -up to the men's hips, say 2 feet 10 inches at midday. The crossings on the 12th and 22nd were made at the same time of day, and the difference of level may have been merely seasonal. When I crossed the Shyok at Khalsar, about 135 miles downstream of the barrier, there was a good deal of water and a Yarkandi had been drowned the day before, but the men at the ferry did not say anything about the water being particularly high. I wonder whether percolation set in just after I left the Chip-chap.

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