The riddle of Snow Lake and the glacier with no outlet

When the British explorer Martin Conway stood on top of the 5128m Hispar La pass in the Pakistan Karakoram in 1892, he described the landscape before him as one of the finest mountain views he had ever seen.

He was expecting to see another valley like the one he had ascended up the Hispar Glacier. Instead they found themselves looking down on a vast basin of snow that he named the Great Snow Lake.

From the midst of the snowy lake rose a series of mountain islands white like the snow that buried their bases, and there were endless bays and straits as of white water nestling amongst them. It was the vast blank plain that gave so extraordinary character to the scene, and the contrast between this and the splintered needles that jutted their 10,000 feet of precipice into the air. Martin Conway, Climbing and Exploration in the Karakoram-Himalayas

In addition to being awestruck by the scene, he was a little nervous. The Hispar La is the apex of one of the longest glacier systems in the world. Behind him on the eastern side was the 49km Hispar Glacier, and ahead lay the 67km Biafo Glacier, a total distance of 116km of ice.

Conway didn’t know this. He was the first explorer ever to stand there, and from the pass, the outlet of the Snow Lake was hidden by a ridge. Various reports had reached him of “a mysterious blocking of this Hispar pass by some change in the glaciers.” They wondered whether the level of the lake had been raised by this blockage, and they would find an impassable icefall at its outlet. When they descended from the pass and rounded the ridge, they were relieved to discover the gently sloping Biafo Glacier forming a path ahead of them.

Exploration usually provides answers to geographical questions, but what happened next in that part of the Karakoram only created mystery. The next explorers to pass that way were the American husband and wife team of William Hunter and Fanny Bullock Workman. They were an intrepid couple, who completed no fewer than fourteen pioneering expeditions in the Himalayas and Karakoram, climbing a number of new peaks. But they were to mapmaking what lemmings are to aviation, and they were frequently getting into arguments with the Royal Geographical Society about their reports.

The riddle of Snow Lake is a good example of this. When they first set eyes on it, they estimated its size to be 300 square miles, and speculated that it might be an icecap, as opposed to simply a huge glacial basin. If it was an icecap, then it would be one of the few outside the polar regions. This would mean that instead of being enclosed by mountains and ridges, it lay on top of them, feeding a series of glaciers around its edges.

In 1908 the Workmans (or should that be the Workmen?) climbed a 5882m summit close to the Hispar La called Cornice Peak. From the summit they believed they could see another strange geographical phenomenon, which Fanny described in one of her books.

Straight across, beyond the Hispar southern ridge, I saw the void between it and another parallel ridge which indicated the presence, 2000 feet below, of Cornice glacier, first discovered by us, from the Col des Aiguilles at the head of the Hoh Lumba glacier, in 1903. The high wall and mass of peaks cutting it off from the Biafo on the east, and the almost perpendicular walls separating it from the Hoh Lumba and Sosbon glaciers on the south were clearly seen, as well as the cols we had climbed at the heads of these glaciers ; also the western boundary formed by the Alchori mountains, which we followed up in 1903 and found no opening in.

I was thus able from this peak to obtain confirmatory evidence of our opinion, formed from observation in 1903, that Cornice glacier lies in a deep hollow, with no observable outlet at any point. We have examined its barriers on every side, and believe it to be an example of what Sir Martin Conway says cannot exist, an enclosed glacier. Fanny Bullock Workman, The Call of the Snowy Hispar

Conway argued there could not be such a thing as an enclosed glacier, or one with no outlet. He said that if this were possible, then for thousands of years snow would have been falling onto it, and the ice would either have piled up so high that it would have overflowed the walls of the surrounding mountains, or melted, finding an outlet as water. Fanny Bullock Workman’s argument was much simpler: she had seen it; he hadn’t.

Shades of Kilimanjaro and the snow on the Equator controversy, perhaps? The Christian missionary Johannes Rebmann was widely ridiculed by scientists when he first described seeing a giant snow mountain on the Equator. They said it couldn’t exist, but of course, it did.

Thirty years passed with these two questions unanswered. Was the Snow Lake an icecap, and was there a glacier without any outlet?

The argument was still unresolved when the dynamic duo Eric Shipton and Bill Tilman travelled to the Karakoram in 1937, hoping to map new territory and answer a few questions. It fell to Tilman to solve the riddle of the Snow Lake. He famously had a dislike of science, preferring exploration for its own sake. His chapter in Shipton’s book Blank on the Map (which, as I’ve mentioned before, is now available as a sensibly priced ebook) is one of the funniest chapters he ever wrote, and well worth a read.

Tilman welcomed the opportunity to prove the scientists wrong. And so:

Shipton and Spender had derided the idea of a completely enclosed glacier, while Auden and I supported the Doctor and Mrs Workman — more, perhaps, from chivalrous motives than for any scientific reason. So upon me lay the task of establishing (I hoped) the truth of the Workmans’ assertion, and of confounding the scientific sceptics — a consummation always desirable, if seldom attainable. Bill Tilman, in Eric Shipton’s Blank on the Map

But before they could solve either of these mysteries, they were to stumble across a third one. They were approaching Snow Lake when they came upon a set of tracks “eight inches in diameter, eighteen inches apart, almost circular, without sign of toe or heel.”

The Sherpas were in no doubt they were the tracks of a yeti. They explained to Tilman that it was one of the smaller yetis that feed on a diet of humans, rather than the larger variety, which feeds on yaks.

“If no one has been here for thirty years then it must be devilish hungry,” quipped Tilman.

The Sherpas were not as amused by this remark as Tilman expected.

Although I’ve never seen a yeti myself, it’s surprising that they believed these tracks belonged to one, even the smaller variety. Everybody knows that yetis have human feet. It’s much more likely these circular tracks belonged to an elephant.

Anyway, I’m digressing. When they reached the Snow Lake, Tilman was disappointed. Instead of the 300 square mile basin the Workmans described, Tilman estimated it to be six miles by three, or at most 20 square miles. In fact it’s a little wider than this, but not by much. It certainly wasn’t what anyone would describe as an icecap.

“It is a disappointingly small area for such a grandiose name, and though one might wish secretly to find the first impressions of earlier and better travellers confirmed, a discrepancy of that size is difficult to overlook,” he said.

Still, at least Tilman still had the opportunity to find a enclosed glacier and confound the scientists. After a brief exploration of the surrounding ridges, they located the Workman’s Cornice Glacier and descended a col, the Sokho La, onto it. Here Tilman had another difference of opinion with his Sherpas, only this time their positions were reversed.

I had tried to impress upon the Sherpas the peculiarities of this glacier — that no river issued from it — that presently we should come to a blank wall and find ourselves entirely shut in by mountains. They listened politely but … their belief in the strange behaviour of the glacier was no greater than mine in the man-eating propensities of the yeti.

They rounded a corner and descended out of the mist. Grass appeared, and they camped in a meadow with flowers, birds and insects. They found these things pleasant after five weeks in the bleak glacier regions, but they hardly indicated the absence of an outlet. The following day they descended a river valley and reached a village, where they were able to obtain some eggs.

“In a drab world it would be refreshing to report the discovery of a glacier flowing uphill, or even of one which did not flow at all,” said a disappointed Tilman. “It gives me no pleasure, therefore, to have to affirm that this glacier behaved as others do.”

In his autobiography That Untravelled World, Eric Shipton reported that he was searching through the archives of the Survey of India a few years later, when he came across Tilman’s sketch map of his journey. Conway’s Snow Lake and the Workmans’ Cornice Glacier were clearly marked on the map, but Tilman had given them two alternative names: Martin’s Moonshine and Fanny’s Fantasy.

Times have moved on, and romantic types will be disappointed to learn that the 10-day Biafo and Hispar Glacier traverse, passing Snow Lake and crossing the Hispar La, is now a popular trekking route. It requires ice axe and rope skills, but many trekking agencies offer fully supported treks.

I’ll finish with this little time lapse video of Snow Lake that I found on YouTube. The soothing music belies the fact that this harsh but beautiful landscape is also the habitat of man-eating yetis.

Watch on YouTube