Himalayan Journal vol.01
The Himalayan Journal

Publication year:

Kenneth Mason
    (G. L. Corbett)
  2. THE SHYOK DAM IN 1928
    (F. Ludlow)
    (Dr. J. de GRAAFF HUNTER)
    (MAJOR D. G. P. M. SHEWEN)
  11. TRAILL'S PASS, 1925
  13. Himalayan Expeditions



IN VIEW of the interest roused by the glacier block in the upper Shyok, and the effects of its possible burst and consequent floods, I have collected in this paper as much of the historical evidence of previous floods in the Indus basin as I have been able to find. It must be remembered that many of the early writers had an extremely limited knowledge of the geography of the region concerned, and that they were, therefore, somewhat liable to jump to erroneous conclusions, based on faulty or insufficient data.

As an example of this I may cite the great Indus flood of 1841, the origin of which was believed by several experts of the time to be in the upper Shyok valley. This belief was based on the analogy of the flood of 1835. Had the size of the Hunza and Gilgit tributaries been realised, such a mistake, which led to years of controversy, could never have been made. An obstruction as far up the Indus as Kumdan, 750 miles above Attock, cannot possibly render the Indus fordable at that place, for the Nubra, the main Indus, and the Gilgit rivers all contribute sufficient water to keep the level high.

I have also investigated the positions of the Shyok glaciers during the last 150 years, in the hope that their history would throw some light on the existing menace.

Transverse glaciers whose snouts project unchecked into main valleys are always liable to cause obstructions. A glacier flows mainly by regelation, that is, by alternate melting under pressure and refreezing. It slides forward, so to speak, on its melted ice. The glacier ends normally at the point where the rate of advance is balanced by the rate of melting. Should there be an excess of snowfall in the neve area of a glacier's basin, it is conceivable that the body of the glacier may advance at a greater rate, especially if its bed is steep, so that, unless there is a balancing increase of melting at the snout, this snout will advance further across the valley, and possibly block it.

There are however in practice one or two important considerations which tend to prevent complete blocks. The bed of a glacier has generally an uneven fall. Where changes of slope occur there will be crevasses and icefalls ; near the snout there may be a dead end." These features will take up some of the advance, before the snout becomes " alive " again.

Once the snout projects into the main river, there is erosion to take into account. Rivers in rapid flow, especially when carrying in suspension sharp moraine material, have enormous erosive powers, and frequently are capable of maintaining a passage under or round an advancing glacier, simply by tearing away the ice. Below such glaciers great ice-floes may frequently be seen, borne along by the swift current . The further down a river, therefore, the less likely are glacial obstructions.

A glacier snout is as likely to advance in winter as at any other time, for though a greater pressure may be required to melt the lower layers of ice upon which the glacier flows, there is almost a complete cessation of melting at the snout. And should the glacier reach the river-bed during winter, there is great danger of a complete block, for the river will be frozen and without erosive power.

Possibly when summer comes, a lake may form above the block, the percolation through the glacier's crevasses and tunnels being much less than the supply of water from upstream. It does not follow, however, that the dam will eventually burst and cause a catastrophe. The lake may fill throughout the summer nearly to the level of the dam and then freeze during the following winter. Early the next year percolation will again commence before the supply of water is resumed, by which time the lake may be almost empty. I saw this happening with the Kyagar dam across the upper Shaksgam, and if might quite easily happen in the upper Shyok.

Supposing the lake rises to the level of the surface of the glacier, i i, is even then by no means certain that the dam will suddenly collapse. A glacier is composed of consolidated layers of ice. Any transverse crevasses act as escapes to the water as the lake-level rises. During the summer they are eroded, in winter they tend to heal, and in the hpri n^ fresh ones may be formed. But the great masses of ice are ii.siially tightly bound, and as a whole the body is compact.

It is generally when a weak line occurs right through the breadth of the glacier that there is danger of collapse. From a study of the records of floods given below, it will be seen that floods caused by the Shyok glaciers appear to have occurred about 1780, in 1835, 1839, 1842, 1903, and 1926. Of these, only those in 1835 and 1926 seem to have been serious down the river as far as Skardu, and the effects of none were felt as low down the river as Attock, 750 miles away. If we examine the positions of the Shyok glaciers, we see that the valley has been blocked or almost blocked during the greater part of that time. Occasionally, indeed, we have records of one or other of them being clear of the main river. But throughout this period there has been continual danger of a block.

It is interesting to compare the effects of the two big floods in 1835 and 1926. On both occasions the villages of Deskit and Liakzun near the Nubra-Shyok confluence were badly damaged, and suffered some loss of life, while lower down the valley near Khapalu the low- lying lands near the river-bed were denuded of farms and the cultivation was destroyed. On both occasions damage, though not very serious damage, was caused below the Indus-Shyok junction near Gol, and at Skardu, but neither in 1835 nor in 1926 is there any recorded destruction below the confluence of the Indus and Gilgit rivers.

Compare the two great Indus floods of 1841 and 1858, the former caused by an earthen dam formed by the collapse of a spur of Nanga Parbat, and the latter by an obstruction, either to the Hunza river or in the Shingshal valley. In 1841, the Indus at Attock prior to the flood was fordable ; the water rose about a hundred feet at that place, about 260 miles below the block, where the lake itself was estimated to have been a thousand feet deep. In 1858, the Indus at Attock was actually above normal prior to the flood. The river rose 55 feet in seven and a half hours at the same place, which was 400 miles below the obstruction.

It is important to distinguish between a glacier dam and a block caused by a rock fall. The latter is composed of heterogenous unconsolidated material, loosely bound together with earth and mud. A lake forming above it is certain to destroy it as soon as its level reaches the top of the dam. As has been mentioned above, a glacier may act as a weir and gradually let the waters disperse gently.

It is difficult to see how anything can be done to avoid these floods. Perhaps something might be done with blocks caused by landslides, provided they were not too big ; but a dam a thousand feet deep and at least a mile wide at the base is a very large proposition, and the cost of demolishing it would probably be prohibitive.

The Kyagar Glacier Dam across the Shaksgam Valley in 1926. The upper level of the ice-blocks on the hillsides indicates the winter level of the frozen lake. The lowered water level shows that percolation through the dam has exceeded drainage into the lake since winter. (Photo. Kenneth Mason.)

The Kyagar Glacier Dam across the Shaksgam Valley in 1926. The upper level of the ice-blocks on the hillsides indicates the winter level of the frozen lake. The lowered water level shows that percolation through the dam has exceeded drainage into the lake since winter. (Photo. Kenneth Mason.)

With glacier obstructions, even when likely to cause serious inundations, such an expense could never be justified. As will be seen from the notes which follow, the two danger spots in the Indus basin are the Shingshal valley and the upper Shyok. In both areas we have large glaciers projecting transversely from the main Muztagh- Karakoram range into valleys of considerable size. These glaciers have large neve fields in regions of heavy snowfall, and they have comparatively steep beds; their snouts are consequently liable to seasonal variation. The block is usually complete when the glacier snout has not only stretched across the valley, but also turned down it for a distance of several hundred yards. From one to two miles of ice some three hundred feet deep would have to be demolished in order to open a passage. It would be a pretty piece of engineering, but it is almost certain that as soon as the breach is made, the glacier will flow onward again and cause another block. Some such suggestion appears to have been made after the flood of 1858, for I find, in a letter addressed to the Secretary of the Punjab and its Dependencies by Major Becher, the Deputy Commissioner of Kashmir, and dated 1st July, 1859, the following remark : " As regards the removal of the obstacle (when such an accident may again occur) by our scientific efforts, I think it is impracticable : the labour of removing such vast masses of mountains, or of glaciers, would be immense.”

Much may be done by careful watching and a sound system of warning. In the Shingshal valley men are despatched each year from the village of Shingshal to report on the positions of the glaciers, and as long ago as 1893 warning of a glacier burst was given in time to prevent loss of life. The problem is not quite so easy in the upper Shyok, for the nearest village, Panamik in the Nubra valley, is four marches away, and separated from the glaciers by the Saser pass. It is however not difficult, and an annual expenditure of a very small sum would prevent scares which are apt to be more costly in the long run.

Indus Floods.

1780 ? Shyok Glacier Flood ?-The evidence for this flood is very scanty. Henry Strachey found in 1848 an old woman of eighty in the village of Shyok who had witnessed a great flood about seventy years before, and who described it to him to have been on a scale similar to that of 1835 (Physical Geography of Western Tibet, p. 55).

1826 ? Flood (origin unknown).-Captain Alexander Cunningham attributes a flood reported to him to have occurred in this year, to a block in the upper Shyok. Henry Strachey, however, writes that there seems to have been no flood of any note in the Shyok between 1780 and 1835. The date and origin of this flood are, therefore, both open to doubt (Physical Geography of Western Tibet, p. 55). As Cunningham is known to have been incorrect in assigning the great Indus Flood of 1841 to the Shyok glaciers, it is reasonable to suppose that he may also have been incorrect about the origin of this.

1835[1]. Shyok Glacier Flood.-Henry Strachey describes this flood from the testimony of Yarkandi traders. According to them it occurred on the 17th day of the 5th month of the Sheep Year, i.e., some time in June 1835. It must be remembered that Strachey had only Thomson's description of the upper Shyok, and at that time the existence of the Chong Kumdan glacier was not established.

It is therefore uncertain which of the three glaciers was the cause of the block in the valley. Strachey writes that the block was effected by the glacier after abutting upon the steep wall upon its eastern side, being thrust upwards by pressure from behind till the ice reached a height of perhaps 700 feet. When the dam burst the Gapshan lake was liberated.

The village of Shyok, the highest permanent habitation in the valley, and distant about 100 miles from the Kumdan glacier is situated on a bank 200 to 300 feet above the river and was above the level of the flood, which from accounts appears to have passed the village during the night, with a rise of about fifty feet. The flood passed the Nubra-Shyok junction, about 150 miles from Kumdan, before daybreak and had run off by noon of the same day. The lower half of the village of Liakzun at the junction was swept away, ten out of twenty-two houses, with all their inmates, men and cattle, being destroyed ; and the village of Deskit suffered equal loss in its low-lying quarters. Strachey estimates that the river here rose not more than ten feet. " In Chorbat of Balti, from 30 to 80 miles below Mid- Nubra, and chiefly in the further part of that distance, no less than 150 farms were swept away from the low-lying lands in the river-bed, but with less destruction to human life, as the flood passed here between daybreak and sunrise..........”

The main portion of the flood-water is said to have run off from Chorbat in a few hours, but the river was above normal in this confined part of the valley for two days. There does not seem to have been much damage below Khapalu (Physical Geography of Western Tibet, pp. 55-57). This 1835 flood had no consequences whatever in the lower Indus, and passed completely unnoticed in Hazara, Chach, and Attock (Becher in J.A.S.B., 1859, p. 227).

1839. Shyok Glacier Flood- Henry Strachey records another flood due to the same cause in the next Hog-Year, 1839 ; " but this was of much less extent, and passed Nubra at midday ; and as all the villages liable to inundation had been destroyed by the former flood, merely carried away the cattle and herdsmen that happened to be out at sea in the river flat " (Physical Geography of Western Tibet, p. 57).

1841. The Great Indus Flood.

(The following account of this catastrophe is compiled from all the evidence collected by Becher, Henderson, Montgomerie, Abbott and Drew.)
In December 1840 or January 1841, the west side of the Lechar spur of Nanga Parbat, opposite Gor, was precipitated into the Indus by an earthquake. The obstruction was approximately a thousand feet deep and completely closed the main river. In April 1841, Jabbar Khan, the Chief of Astor, warned Kashmir of this block and stated that the river would probably be held back for another month, and about the same time Raja Karim Khan of Gilgit sent warnings, written on birch-bark, down the main valley of the Indus.

At the end of May, or more probably in the beginning of June, the waters seem to have reached the top of the obstruction, and the lake, which then extended for nearly forty miles in length, and which was a thousand feet deep at the dam, was liberated.

Prior to the burst, the Indus at Attock was, and had been for many months, easily fordable, yet, in spite of this state and the warnings received, little notice was taken. The lake emptied itself in twenty-four hours, and swept everything before it.

A Sikh army was encamped on the plain of Chach, near Attock, close to the river. About 2 p.m. on a day very early in June the roar of waters was heard, and before the soldiers could reach safety, the river came down with an immediate rise of nearly eighty feet.

An interesting account of the flood narrated by a zemindar of Torbela is given by Captain Abbott in the Journal of the Asiatic Society of Bengal, Vol. XVII, 1848, p. 231, sqq.

"We began to exclaim, ‘What is this murmur? Is it the sound of cannon in the distance? Is Gundgurh bellowing? Is it Thunder V Suddenly someone cried out: 'The Rivers come!' And I looked and perceived that all the dry channels were already filled and that the river was racing furiously in an absolute wall of mud, for it had not at all the appearance or colour of water. They who saw it in time easily escaped. They who did not, were inevitably lost. It was a horrible mess of foul water, carcasses of soldiers, peasants, war-steeds, camels, prostitutes, tents, mules, asses, trees, and household furniture, in short every item of existence jumbled together in one flood of ruin. For Raja Goolab Singh's army was encamped in the bed of the Indus at Koolaye, 3 coss above Torbaila, in check of Poynda Khan. Part of the force was at the moment in hot pursuit, or the ruin would have been wider. The rest ran, some to large trees which were all soon uprooted and borne away, others to rocks which were speedily buried beneath the waters. Only they escaped who took at once to the mountain side. About five hundred of these troops were at once swept to destruction. The - mischief was immense. Hundreds of acres °of arable land were licked up and carried away by the waters. The whole of the Seesoo trees which adorned the river's banks: the famous Rurgutt tree of many stems, time out of mind, the chosen bivouac of travellers, were lost in an instant. The men in the trees, the horses and mules tethered to the stems all sunk alike into the gulf and disappeared for ever. As a woman with a wet towel sweeps away a legion of ants, so the river blotted out the army of the Raja "

A letter is quoted by Dr. Falconer as early as the 6th July, 1841, probably not more than a month after the catastrophe (Journal of the Asiatic Society of Bengal, Vol. X, 1841, p. 616). ".........Hundreds of villages and towns were swept away, with thousands of human beings and cattle. The Lundaye (or Cabul river, which joins the Indus close above the fort at Attock) had its water held up and forced back so as to inundate the towns of Nowshera and Akora........In the Huzara country, the flood swept away artillery guns with many hundreds of infantry and sowars ; and old Sham Sing Atarewallah, a Seik sirdar, had all his camp and followers carried downstream. ..... I have as yet only heard of the course of the inundation as far as Dera Ismail Khan, whence also the accounts are very distressing, and so they will continue to be, I suppose, till it reaches the sea, for nothing can contain it

The actual height of this flood at Attock is believed by early writers stationed there to have been approximately 92 feet above the low winter level of the river and approximately 42 feet above the normal high flood-level of summer. Early accounts agree that there was a definite bead of water, and not a mere rise of the river level.2
1842. Shyok Glacier Flood- According to Longstaff, a small flood took place in this year (G.J., Vol XXXY, p. 647).

1844. Gilgit River Flood.-Drew obtained evidence of a flood in the Gilgit valley in 1844. It appears to have had its origin near the head of the Ishkuman valley, which Hayward recognised as the source of floods, past and to be expected. This flood appears to have spent itself by the time it reached the Indus. It passed unnoticed at Attock (Jummoo and Kashmir Territories, p. 418).

2 Dr. Falconer in a letter to the J.A.S.B., dated July 6th, 1841, commented on the first reports of the cataclysm. These reports placed the site of the obstruction near " the plains of Gilgheet," and stated that it had held back the Indus, so that " the river at Attock was converted into an easy ford." Falconer set aside the Gilgit origin and propounded the theory that the stoppage occurred much higher up, on the Indus above Skardu, or more probably in the upper Shyok (approximately 750 miles above Attock). He had himself visited Skardu, where he had learned from Raja Ahmad Shah that great floods occurred occasionally (one had happened as recently as 1833 or 1835), in consequence of the advance of the upper Shyok glaciers. Afterwards Captains Abbott and Alexander Cunningham both attributed this 1841 catastrophe to glacier blocks in the upper Shyok, and as late as the 7th January, 1859, Captain Henderson, who was stationed at Attock, and. who took careful note of the great flood of 1858, wrote to the J.A.S.B., supporting this view. It must be remembered that at that time the Gilgit and Hunsa branches of the Indus were almost unknown, and that a block as high up the river as the Shyok could never cause the Indus at Attock to be fordable unless blocks occurred simultaneously in the main Indus and in the Hunza river.

In July 1859, Major Becher, the Deputy Commissioner of Kashmir, wrote to the J.A.8.B., and quoted a certain newswriter, Mirza Ahud, who had written to Sir George Clerk at Ambala in April 1841, prior to the bursting of the dam, and placed it on the Indus below Bunji. Independently of Becher, Captain Montgomerie of the Great Trigonometrical Survey of India came to the same conclusion, after questioning men who had seen the dam while the lake was in existence. F. Drew, in his Jummoo and Kashmir Territories, p. 414, sqq., publishes an account of the flood which agrees closely with the account given above, and there is not the slightest doubt that the dam was directly caused by a great fall of rock from the western spurs of Nanga Parbat.

1855. Middle Indus Flood.-Godwin Austen reports a minor flood in the middle Indus about 1855. His report runs : “Camp Gol on Indus, 29th August, 1860. A flood occurred at Gol about five years ago in the month of June. Very muddy water came down the ravine (slowly at first), and the people who saw it left their houses and ran up the hillsides. Twelve old men, who could not run away, were drowned, twenty houses and about five hundred apricot trees, were washed away. There was but little snow on the hills at the time, and the ravine is by no means a large one. The villagers go up it constantly and yet were not aware of its being in any way dammed up, though the water must have been in considerable quantity, as the flood altered the course of the Indus. It is a mystery to me where sufficient water could have been collected. This account was given by Wazzir Husain of Gol" (J.A.S.B., Vol. XXX, 1860, p. 107). Gol is about four miles below the Shyok-Indus confluence.

1858. The Second Great Indus Flood.

(The account of this flood is taken from the memorandum written by Captain Henderson, who was stationed at Attock at the time the waters passed that place.)
Captain Henderson states that the Indus river actually rose earlier this year than normally, and that it was far from fordable at Attock throughout the year. He was actually on the river in a small row-boat at 6 a.m. when the first flood-waters began to arrive at Attock. He records that the river rose approximately 26 feet in the first hour, 12 in the second, 7 in the third, 4 in the fourth, and 6 in the next 3 ½ hours when it attained a maximum at 1-30 p.m. It thus rose 55 feet in 7 ½ hours. There was no wall of water or wave.

The annual flooding at Attock in July and August normally reaches fifty feet. On this occasion it reached 80 feet above its cold weather level, i.e., 30 feet above its normal, and only 12 feet below the level of the great flood of 1841.

The waters extended over the Chach plain, and rolled over the stream of the Kabul river, filling up its channel and adjacent low ground to a length of thirty miles from the junction, with an average breadth of more than two miles, and a depth of 60 feet above the original level of the stream near the junction. The Kabul river acted as a safety valve and, at the expense of much destruction of this well- cultivated tract of country, saved the lower valley of the Indus.

Below Attock the flood's violence rapidly diminished. Between Shadipur and Makhad the rise was only 10 or 12 feet above the normal flood. At Kalabagli it was only 8 feet above, and below that place it was insignificant.

The fall of the river at Attock was slow at first. After high flood it only dropped eight feet in five hours. It remained above normal flood throughout the 11th August until evening. , During the night of 11/12th it fell twenty feet, and on the 12th the river was almost down to its pre-flood level. The waters of this flood, therefore, took approximately 48 hours to pass Attock (J.A.S.B., Vol. XXVIII, 1859, pp. 199 sqq.).

The site of this dam was certainly on the Hunza river or a tributary to it, for the gateway of Nomal Fort was found among the debris.3 Major Becher early in 1859 questioned men from Gilgit, Hunza, Nagar and Gor. All agreed that the obstruction was in the Hunza valley about a day's march above the fort of Hunza (Baltit). It was stated to have been caused by the subsidence of a mountainside called Phungurh, on the left bank, which collapsed owing to the action of rain and snow during the winter of 1857-58. The river was dammed for six months, during which time warnings were sent down the main river and down the Indus (J.A.S.B., Vol. XXVIII, 1859, pp. 219 sqq.).

Captain Montgomerie of the Survey of India undertook independent inquiries and came to the same conclusion as Becher ; and Drew, in his Jummoo and Kashmir Territories, p. 419, sums up the evidence, and after inquiring again at Gilgit, concluded that Becher and Montgomerie were right, except that he placed the barrier in the Shingshal tributary of the Hunza river and not in the main valley itself. According to Drew, the flood was caused by " the bursting of the barrier of a lake that had been made by a land-slip, not by a glacier, in the Shin(g)shal valley."4
3 Captain Henderson of Attock had already accepted the fallacy that the 1841 flood had its origin in the upper Shyok glaciers, after reading and being convinced by the writings of Abbott and Cunningham. Owing to certain similarities between the two floods and to the fact that warnings were received on both occasions down the Indus, he concluded that the 1858 flood was caused by the Shyok glaciers also. Where the two occasions differed, Henderson assumed that the account of the earlier one was at fault, and he paid no heed to the very important difference that while the river at Attock before the 1841 flood was fordable, it was during the summer of 1858 higher than normal. There is nothing in Henderson's account of the happenings at Attock incompatible with a Hunza valley origin for the latter, and I feel certain that Henderson was wrong.

4 This mention of the Shingshal valley is the first that I have been able to trace in any records. Drew's account was written in the early 'seventies, before we knew where it was or what it contained ; and his enquiries were sufficiently long after the occurrence for him to be liable to error, especially in view of the then prevailing geographical ignorance of Hunza.

Mr. H. Todd, the present Political Agent of Gilgit, who has kindly looked through these notes has now written to me as follows :-" I am surprised that you do not refer to the Ghammesar landslide some seven miles above Altit and one mile below Atabad. I think it must have been responsible for a very big flood-probably the one that occurred in 1858. At Ghammesar a huge landslide from the mountains on the left blocked up the valley. The people say that the lake stretched right back to Pasu .... The Mir points out a line of silt on the hill above the present water level at Pasu, and declares it to be the bed of the lake then formed. This would make the lake of enormous size. To make such a rise as you mention at Attock from such a small river as the Hunza, there must have been a tremendous accumulation of water, so perhaps he is right."

This account agrees so closely with the contemporary evidence obtained by Becher and Montgomerie, that I feel certain that the Ghammesar landslide was the cause of the 1858 flood.

1865. Gilgit River Flood.-Drew mentions a flood which passed Gilgit at the end of June 1865, or beginning of July, and which, like that of 1844, originated in the Ishkuman valley. Five men of the guard at Gilgit rope-bridge were drowned, but the effects of the flood seem to have been very local, and it seems to have passed down the Indus unobserved (Jummoo and Kashmir Territories, p. 420).

1873 ? Hunza Valley Flood.-In 1913 I was informed by the head man of the village of Pasu that about forty years before that date, the Batura glacier had advanced and blocked the Hunza valley, causing a lake to form north of it. I was told that this obstruction eventually burst, and that the consequent flood carried away the old village of Pasu, and caused destruction down the valley.

The whole appearance of the Hunza valley about Pasu shows evidence of having been badly damaged at some time by water, but I am not convinced that this was due to a flood. And the actual date of the occurrence is very much open to doubt. I do not believe that the Batura glacier has blocked the Hunza valley in recent years, for there is much too much water draining into it during the summer. The current of the river is in fact, in my opinion, so strong in summer at this point, that erosion would almost certainly keep a channel open.

Nor is there any other record of a flood about 1873, certainly not in the Indus valley, which must have been affected if the main valley had been obstructed. I therefore suggest that the destruction of the old village of Pasu was caused by the 1858 block in the Hunza valley, near Ghammesar, which formed a lake extending to and submerging Pasu.

1893. Shingshal Valley Flood.-Sir Francis Younghusband, in the discussion after the Vissers' paper before the Royal Geographical Society on 22nd February, 1926, remarked :-" In 1893, there was a glacier block (in the Shingshal), which burst in that year. The lake was watched and warning given. Disaster was thus prevented" (G.J., Vol. LXVIII, p. 457).

1903. Upper Shyok Valley Flood.-Dt. T. G. Longstafi records :-" In 1903 a bad flood occurred, which Oliver (British Joint Commissioner for Ladakh) attributes to the bursting of the Kichik Kumdan dam " (G.J., Vol. XXXV, 1910, p. 649).

1906. Shingshal Valley Flood.-A glacier in the Shingshal valley dammed the river prior to July this year, and a lake formed behind the barrier. " In July a most serious flood was caused in this way, which, amongst other damage, wrecked the suspension bridge at Askurdas, and the bridge across the Gilgit river at Chamogah and practically destroyed the whole road between Nomal and Chalt " (Frontier and Overseas Expeditions from India, Vol. I, p. 10).

1926. Upper Shyok Valley Flood.-In June 1925 the Roosevelt expedition found the Shyok valley blocked by the Chong Kumdan glacier, and was forced to turn back and make a detour over the Depsang plains. This block appears to have continued throughout the following winter and spring. In June 1926 the valley was still blocked, and the lake which had formed above extended to beyond Yapchan (Gapshan), some six miles above the dam. The depth of water in the Shyok river was 1 foot in June and 2 feet in October some three weeks before the ice-barrier gave way.

In late October the dam broke, and the pent-up lake escaped and flooded down the Shyok. The flood swept down the valley and carried away the suspension bridge at Tirit, just above the Nubra- Shyok confluence and 150 miles from the Kumdan snout. The village of Deskit, near the same confluence, was almost destroyed, and the excellent pony-road between Deskit and Khapalu, completed in 1912, was torn away in a number of places. Wherever cultivation was low-lying, as at Abadan and Surmo, it was completely destroyed, and the fields buried beneath an avalanche of boulders ; and except for a few houses on a knoll, the whole village of Abadan, 250 miles from the Kumdan glacier, and consisting of 23 houses, was destroyed. In the gorges between Unmaru and Biagdangdo, some 24 to 36 miles below the Nubra confluence, and from 182 to 194 miles below the dam, the flood is said to have passed about 70 feet above the normal flood level. This gorge checked the flow, and permitted the flood to expend some of its force up the broad Nubra river, where the village of Liakzun was almost wiped out, and where some central Asian caravans suffered loss. The flood-waters do not appear to have travelled up the Nubra more than about ten miles, and the loss of life appears to have been very small.

Skardu is approximately 350 miles below the site of the Shyok dam ; very little damage occurred at this place in 1926. Bunji, 130 miles lower down, suffered no ill effects, and the suspension bridges above and below this place were undamaged. At Attock, 750 miles from the Shyok dam, the flood seems to have passed almost unnoticed.

1927. Shingshal Valley Flood.-Captain Morris records that in June or July " one of the glacier lakes above that place- (Shingshal)-burst and caused heavy floods in the valley." In 1925 a considerable lake was observed above the Khurdopin glacier, under which the waters then found an outlet. It seems probable that this outlet became choked, probably by pressure from behind, and that the catastrophe, which was predicted by the Vissers in 1925, occurred two years afterwards, though the damage does not appear to have been severe (Among the Karakoram Glaciers, p. 128; G.J., Vol. LXXI, p. 525).

The Chong Kumdan, Kichik Kumdan, and Aktash Glaciers.

The following notes have been collected to show as far as possible the positions of the snouts of the three glaciers in the upper Shyok which are liable to cause obstructions to the main valley. It will be observed that during many of the years the actual positions are not available. Fortunately, however, the main trade route gives some indication, for when all the glaciers are clear of the Shyok river-bed, traders pass directly up the valley. When one or more of the glaciers project into the river-bed, summer caravans must cross the Shyok at Saser Brangsa and take the Chongtash-Murgo route to the Depsang plains. This fact is, however, no proof of a complete block, for whereas in summer there may be too much water in the Shyok for caravans to ford immediately below the glaciers, in winter the level is so diminished that there may be a clear passage over the river ice. The state of the terminal ice can only be inferred either by an actual visit to the snouts, by the condition of the Shyok ford at Saser Brangsa during the months of high water (July to September), or by the liberation of a lake caused by the bursting of a glacier dam. Nor can small seasonal advances and retreats of the glacier snouts be determined when these snouts project into the river, for there is no means of estimating the amount of terminal ice eroded by the current.
All three glaciers are of the transverse type. The lengths are Chong Kumdan, 9 miles ; Kichik Kumdan, 7 miles ; Aktash, 5 miles. Their falls, 3,000 feet (333 feet per mile) ; 3,500 feet (500 feet per mile) and 2,000 feet (400 feet per mile), respectively.

About 1780.-Henry Strachey in 1848 obtained evidence of a flood caused by the bursting of one of the Shyok glacier dams about 70 years earlier (Physical Geography of Western Tibet; p. 55).

1812.--Mir Izzet Ullah passed up the banks of the Shyok river, " beyond the glacier of Khamdan" (Calcutta Quarterly Oriental Magazine, 1825, Vol, III). The glaciers appear to have been clear of the river for Izzet Ullah writes :-

“On our left hand between South and West is a mountain of ice, which remains unmelted throughout the year" (Travels beyond the Himalaya, by Mir Izzet Ullah, transl. H. H. Wilson in J.A.S.B., Vol. VII, 1842-43, p. 297).

1812-24.-All glaciers appear to have been clear of the river during this period, and there seems to have been no flood during this time. About 1824, the snouts were about a quarter of a mile from the eastern wall of the valley (Physical Geography of Western Tibet, p. 56).

1826 ?-A flood in this year is attributed by Captain Alexander Cunningham to the glaciers in the upper Shyok. Both the date and the origin are open to doubt (J.A.S.B., Vol. XXVIII, p. 222).

1829-30 - A doubtful itinerary by Gardiner during this period seems to refer to the Karakoram route (J.A.S.B., Vol. XXII, p. 284). The places mentioned are unrecognisable, and nothing can be deduced.

1835[2].-Henry Strachey describes the upper Shyok glacier block and subsequent flood in Physical Geography of Western Tibet, p. 55. According to him this flood was caused by the Chong Kumdan glacier, which after abutting upon the steep wall of rock upon its eastern side is " thrust upwards by the pressure from behind till the ice reaches a vast height .... perhaps 700 vertical feet, above the valley bottom." This dam burst in June 1835, but in spite* of the disastrous effects, only the terminal ice was carried away, and the trade route was still unable to follow the valley past the snouts.

1839.-Strachey writes : " In spite of so great a cataclysm as this in 1835, a debacle from the Kumdan glaciers occurred again in the next Hog-Year or 1839 " (Physical Geography of Western Tibet, p. 57).

1842.-According to Longstaff, another small flood took place in this year (G.J., Vol. XXXV, p. 647). The period 1835-1842 appears to have been one of maximum advance of the ice.

1848-In August Dr. Thomas Thomson, the first Englishman to reach the Karakoram pass, examined the Shyok glaciers from Saser Brangsa. On the 15th he found the average depth of the Saser ford to be about a foot and a half, while at one spot it was two feet deep. At this period of the year this almost certainly indicates a partial block of the valley above. Later in the month he visited the Aktash and Kichik Kumdan glaciers.

The Aktash glacier extended right across the Shyok river, which flowed out below the ice. The ice, however, did not extend to the foot of the precipice on the left bank as far as Thomson could see, but he was unable to judge the position of the snout in the middle. Thomson noted the ancient moraine, " deposited at a period when the glacier must have been more bulky than it now is," and crossed the glacier with some difficulty.

He also found the Kichik Kumdan glacier impossible to cross, for he records :

" At the bottom of the valley it spread out in a fan-shaped manner to a width of at least a mile ; perhaps indeed much more, for as I failed in getting round it, I was unable to ascertain precisely." He found that at its south-east corner it was nearly a hundred yards from the river, and here was its true snout from which issued a considerable stream. Further on he found the glacier " fairly projecting into the Shyok in such a manner that I could not see anything of what lay beyond." The terminal cliff varied in height from fifteen to thirty feet.

Thomson believed that there was a third glacier beyond, but he did not see it. He adds that it was highly improbable that any permanent lake existed above the glaciers (Western Himalaya and Tibet by Thomas Thomson, pp. 420, 440 sqq.).

1855.-Captain Henderson found the glaciers projecting into the Shyok in August of this year (J.A.S.B., Vol. XXVIII, 1859, p. 222).

1862.-First survey of the upper Shyok by E. C. Eyall of the Survey of India. The Aktash glacier is shown one mile, and the Kichik Kumdan half a mile back from the river. The Chong Kumdan is shown as closing the road, but not blocking the river.

1864.-W. H. Johnson, Survey of India, found that the summer road was over the Depsang plains, so presumably the valley route was again rendered impassable by the glaciers.

1865-During the winter Johnson passed down the Upper Shyok. His itinerary is thus described :-

" The route from Gapshan passes some large glaciers and lays down the right bank of the Shyok river, till its junction with the above- mentioned stream (the Saser) whence it ascends to Sarsil (Saser Brangsa)." From this it would appear that all the glaciers were clear of the Shyok river in this winter, though it is possible that Johnson passed the snouts on the river ice, the river itself being of course much reduced from its river level (Johnson's Itineraries, in old Survey of India Report).

1869-R. B. Shaw in July returned from Kashgaria. The Chong Kumdan projected into the Shyok and compelled him to ford the river. The Kichik Kumdan completely blocked the road, having advanced since April of this year, when one of his guides had passed the snout by the river-bed. Shaw found the ice of the glacier right up to the cliffs of the left bank of the Shyok, the river forcing its way under tunnels in the ice. The Aktash glacier does not seem to have formed any obstacle (High Tartary, Yarkand, and Kashgar by R. B. Shaw, p. 433, and illustrations, p. 434).

1873.-Gordon and other members of the Forsyth Mission made their way round the snouts of the Kichik and Chong Kumdan glaciers. Of the Kichik Kumdan he writes : " The end of the glacier continues down the right bank of the stream " (i.e., the Shyok) " for over two miles, forming a perfect wall of ice rising from the water about 120 feet, and showing a surface covered with countless pinnacles and points. Portions of it still stand at several places on the opposite bank, where the original mass was forced against the great up-rising red cliffs, and blocked the stream, thus forming a lake, which at last burst this ice-barrier by the increasing pressure of its collected waters " (The Roof of the World, pp. 17, 18, and Frontispiece).

Of the Chong Kumdan he says : " It shoots down from a lateral valley to the north-west, and almost touches the opposite side of the valley. It probably at one time formed a long and extensive shallow lake above" (Op. cit., p. 8 and illustrations). Gordon does not mention the Aktash glacier, which may, therefore, be assumed to have been clear of the river.

1889.-Younghusband travelled by the Depsang route. At this period, therefore, it may be presumed that the road up the valley was blocked (The Heart of a Continent, p. 225).

1894.-Church and Phelps passed the snouts of all the glaciers.

1899.-The British Joint-Commissioner commenced building a road along the valley. It was carried beyond the Aktash glacier, but progress was arrested by the advance of the Kichik Kumdan glacier. Traders however continued to pass round the ends of all glaciers in winter-time, up to the winter of 1902-03.
    1902 -In April, Sven Hedin passed the snouts of the glaciers on the river ice. The Aktash glacier was well clear of the road. The Kichik Kumdan was stretching almost to the cliffs across the river, and there was only a narrow passage 10 metres wide near the cliffs. The Chong Kumdan did not stop the road, although there was little room to spare, it being about 30 to 40 metres from the diminished river-bed (Scientific Results of a Journey in Central Asia, Vol. IV, p. 410, where seven photographs are shown ; see also G.J., Vol. 36, 1910, p. 186, where there is a discussion on Longstaffs observations of 1909).

    1903 -A bad flood occurred in the Shyok, attributed by the British Joint-Commissioner to the bursting of the Kichik Kumdan dam.

    1905 -The Aktash glacier advanced across the river-bed but the river forced a passage under the ice. Ellsworth Huntington in June took the Depsang route (The Pulse of Asia, p. 81).

    1906 -David Fraser wrote of his visit to the upper Shyok in 1906 : " I saw it " (i.e., the Aktash glacier) " when crossing the Shyok river at a distance of about five miles. Unfortunately I was unable to visit the upper side owing to the state of the water " (Marches of Hindustan, p. 142). It is probable that the Aktash did not completely block the valley, or there would not have been sufficient water to deter Knight from visiting it.
      1908. -Sir Aurel Stein crossed from Central Asia over the Depsang plains in October of this year. It seems probable that the Shyok was almost if not entirely blocked by one or more glaciers at this period (Ruins of Desert Cathay, Vol. II, p. 486).
        1909 -All three glaciers had advanced and blocked the Shyok. Longstaff, who made this observation, shows on his map the Aktash and Kichik Kumdan glaciers right across the river-bed, while he shows the Chong Kumdan as leaving a passage for the river. No lakes are however, shown upstream of any of the glaciers, and none are mentioned. It appears, therefore, that the river escaped through tunnels or by percolation through the sandy bed. About the Chong Kumdan Longstaff writes : " Its snout projected far into the river, but we were unable to see whether any part of it reached the further bank (G.J., Vol. XXXV, p. 641, where there are photographs of the Aktash glacier across the road and of the others from the south. See also the appendix to Longstaff's paper, p. 647, of the same Journal.) Sven Hedin considered that there had been a considerable advance of the Aktash glacier since 1902 (G.J., Vol. XXXVI, 1910, p. 186).
          1914.-De Filippi put his depot down on the Depsang plains. The Eimo glacier was carefully surveyed and the Chong Kumdan glacier sketched. The latter is shown on Wood's map as reaching the Shyok river bank. The Kichik Kumdan and Aktash glaciers are not shown on Wood's map, which omits the portion between the Chong Kumdan and Saser Brangsa, Wood in his report writes that in June, Shib Lai of the Survey of India, was sent back from the Depsang plains, to " carry out so far as he was able a survey of the old route up the Shyok river. He found the Kumdan glaciers blocking the river, and was unable to cross them." Presumably the Kichik Kumdan is referred to. (Explorations in the Eastern Karakoram and the Upper Yarkand Valley, p. 7).

          1919-1925.-I was told in 1926 that the valley route had been open for six years previous to 1925.

          1925.-The Roosevelts, who passed up the valley in June, write : " Started up the Shyok river from Saser. We had to ford some five times during the day .... We passed the next fords without trouble. Just when we thought the worst of the difficulties were behind us, we turned a bend and saw the Rimo glacier stretched across the entire valley .... Two hours' fruitless search convinced us that there was no possibility of getting the ponies across."

          The glacier here called the " Eimo " is most certainly the Chong Kumdan. This point has been referred to Kermit Roosevelt, who agrees.

          The party was forced to turn back and crossed the Depsang plains. Here they met a Yarkandi caravan which had attempted to take the Shyok route from the north, but had been stopped by the same glacier (East of the Sun and West of the Moon, pp. 59-61).

          1928.-In early June the valley was reported dammed by two glaciers, the Chong Kumdan and probably the Kichik Kumdan. A lake had formed upstream of the former, and by August extended to beyond Yapchan or Gapshan, a distance of some six miles from the glacier. The depth of water in the Shyok river at the Saser Brangsa ford was 1 foot in June and 2 feet in early October some three weeks before the ice-barrier gave way.

          The dam burst at the end of October.

          1928.-During the summer the Chong Kumdan glacier was again reported to be blocking the Shyok valley, and it was expected that the barrier would give way during the period of high flood. Ludlow examined the glaciers early in August. He found the terminal ice- pinnacles of the Aktash glacier, except in one spot to be 200 yards or more from the Shyok; but he doubted whether the Aktash would ever completely block the Shyok, and form a lake upstream of it. He found no indication of such a lake in the past, and considered the Shyok bed sufficiently sandy and porous to allow drainage under the ice, as seems to have happened in 1905.

          Ludlow found the Kichik Kumdan ice-pinnacles more than a hundred yards from the river bank, but remarked that the actual tongue nearly reached it. From his photographs it is evident that his belief that the glacier is retreating is well founded. It is also probable that the ice is diminishing in volume.

          The Chong Kumdan completely blocked the Shyok river, and its snout had spread down the main valley for a distance of from 500- 600 yards. The dam rose steeply for this distance from its tongue, and was covered with detritus. The lake up river of the Chong Kumdan dam extended above the Chip-chap confluence for a distance of 3 ½ -4 miles, giving it a total length of from 10-12 miles. Its level was rising about 1 ½ feet a day on August 1st and 2nd, though Ludlow considered this rise abnormal (see Ludlow's paper The Shyok Dam in 1928, ante). A good account with some interesting and instructive photographs appeared in the Times of India, Illustrated, for October 14th and 21st, 1928.

          [1] Vigne, writing in 1838, says that this flood occurred five years before Alexander Cunningham in his Ladak, and Becher in the Journal of the Asiatic society of Bengal, quoting from Vigne, accept the date of the flood as 1833 It is difficult now to make certain which date is correct, but I prefer to accept 1835 on the evidence of Strachey.

          [2] Vigne describes a flood in 1833, or rather states that a flood occurred five years before 1838. According to Strachey, there was no flood between about 1780 and 1835 ; and he states that it occurred " on the 17th day of the 5th moon of the Sheep Year," i.e., in June 1835. It seems certain that Vigne refers to this flood, and that both Cunningham in his LadaJc, and Becher in J.A.S.B., Vol. XXVIII, 1859, p. 226, are wrong in accepting Vigne's date. According to Strachey, Cunningham is wrong also in assigning the 1826 flood to the Shyok glaciers.