Khumbu Icefall and the Valley of Silence

National Geographic has a blog written by people who are now climbing Mount Everest. Here’s Sam Elias training in the Khumbu Icefall near the Everest Base Camp:

As usual, it’s the Sherpas who impress me most:

Years of experience, or maybe the mountain itself, had told the Sherpas that passing through the Ballroom on this day was not a good idea, something would happen. “Big ice will fall.” Panuru’s words echoed in my head. “How do they know?” I wondered.

I was sitting in my tent fitting my crampons onto my boots when I heard it. I know the sound now. Before, when the loud rumbling began I instinctively thought of a giant semi barreling down a highway. But there are no vehicles here.


Every year, the route through the Khumbu is set by the “ice doctors,” a small team of Sherpas who take mortal risks to navigate the safest passage through the Icefall, putting up ropes in the steep sections and stretching ladders across the abyss-like crevasses.

Crossing the ladders is an adventure for some. For the Sherpas, setting them up is a job.

Khumbu Icefall

Suppose you take the southeast route to Mount Everest, on the Nepal side. When you climb up from Base Camp, the first thing you’ll hit is the Khumbu Icefall, a crazy and ever-changing mass of ice at the bottom of the Khumbu Glacier:

As the National Geographic blog put it:

Like a gargantuan bulldozer, the Khumbu glacier plows down off the Lhotse Face between Mounts Everest and Nuptse. Dropping over a cliff just above Base Camp, this mile-wide river of ice shatters into building-size blocks and steeple-size spires called seracs. It’s riven with cracks called crevasses that can be hundreds of feet deep. To reach our expedition’s two goals — the Southeast Ridge and the West Ridge, which both begin atop the Khumbu glacier in the Western Cwm — we must travel up through this labyrinth of raging ice.

To cross the crevasses, you use bridges that the Sherpas have made by lashing ladders together with rope. Here’s Nima Dorje Tamang crossing one. The clouds are like a ceiling… but there’s no floor:

The picture above is again from National Geographic.

The glacier advances about a meter each day around here. Most climbers try to cross before the sun rises, when the cold keeps things frozen. As the intense sunlight warms things, the icefall becomes more dangerous. Blocks of ice tumble down the glacier from time to time, ranging in size from cars to houses… and sometimes entire large towers of ice collapse. They say bodies of people who die in here sometimes show up at the base of the icefall years later.

Here’s Kenton Cool talking about the Khumbu Icefall. “It can implode underneath you, it can drop on you above – or god forbid, you can fall into its inner depths, never to be seen again.”

And this is photographer Leo Dickinson speaking about the dangers of this place. Look at the fellow poking at snow with a pick around 0:58, revealing that it would be deadly to step there!


The Valley of Silence

Suppose you succeed in crossing the Khumbu Icefall—including the last crevasse, shown in this photo by Olaf Rieck. Then you have reached the Western Cwm, also known as the Valley of Silence:

In the middle background is Lhotse. At far right you see a bit of Nuptse. And at left there’s Sāgārmatha, also known in Tibetan as Chomolungma… or in English, Mount Everest.

‘Cwm’, pronounced ‘coom’, is Welsh for a bowl shaped valley, also known as a ‘cirque’. This one is a 4-kilometer-long valley carved out by the Khumbu Glacier, which starts at the base of Lhotse. It’s the easiest way to approach Everest from the southeast. However, it’s cut by massive crevasses that bar entrance to the upper part: here you must cross to the far right, over to the base of Nuptse, and through a narrow passageway known as the Nuptse corner.

It’s called the Valley of Silence because it’s often windless and deathly quiet. On days like that, the surrounding snow-covered slopes surrounding are so bright that the valley becomes a kind of solar oven, with temperatures soaring to 35 °C (95 °F) despite an elevation of 6000 to 6800 metres (19,600-22,300 feet). But when sun turns to shade, the temperature can plummet to below freezing in minutes!

The photo above was taken by the Moving Mountains Trust. See the people? You may need to click for a bigger version! For more, see:

• Alan Arnette, Life in the Western Cwm.

Want to go further? When you’ve reached Base Camp II near the top of the Western Cwm, you still have 2300 meters to climb… and now it gets steep! I’m sorry, I’m quitting here and heading back down—it’s my bedtime. Good luck!

For more

Cut your carbon footprint. Travel virtually:

Mount Everest summit—interactive 360 degree panorama.

Reality Maps viewer for Everest.

Michael Murphy writes:

I had become intrigued by the story of Marco Siffredi, a French snowboarder who was the first to successfully descend Everest on a snowboard via the Norton Couloir. His second attempt to descend a far more serious route, the Hornbein Couloir ended in his demise.

[….] I used Reality Maps to trace his route. It is no wonder he did not make it.

17 Responses to Khumbu Icefall and the Valley of Silence

  1. arch1 says:

    Pardon the dilletante-ish nature of the Q, but for anyone who knows..

    If Khumbu icefall is so dangerous, why do people elect to go through it rather than skirting it by either climbing up the S side of the W ridge, or the N side of the Lhotse/Nuptse ridge?

    Would bypassing Khumbu be even more dangerous for some reason? Or is the immediate danger of Khumbu (most of which may(?) be borne by the route setters) being traded off for time/convenience/energy (which come to think of it might pose dangers of its own, and not just to route setters)?

    • John Baez says:

      arch1 wrote:

      Pardon the dilletante-ish nature of the Q…

      Sure! It was a dilletante-ish post. It’s not like I’m a mountain climber or something.

      I can only guess that the Khumbu Icefall is the least bad of alternative ways to get up from the southeast.

      I think there are also routes from the north, but there you have to go through Tibet, which is an administrative hassle… I don’t know how much easier or harder those climbs are. If anyone knows, I’d like to hear. (I know this isn’t arch1’s question.)

      • Frederik De Roo says:

        Here’s a nice comparison of the two main routes.

        • arch1 says:

          Thanks, this *was* very interesting. It also starts to quantify the icefall danger, and it also suggests a partial answer to my Q (people may elect not to bypass Khumbu *on the left* because of the avalanche risk).

      • Patrick Powers says:

        It is harder to get a permit from the Chinese. The mountain is made of limestone, and the strata are slanted so that they rise from south to north. This means that the cliffs on the north side are more daunting.

        Reinhold Messner climbed the north side solo during the monsoon, which still seems impossible to me. He bypassed the cliffs by climbing a couloir.

  2. arch1 says:

    (Just to clarify – the Q isn’t asking about an alternative global route, but rather about the possibility of “skirting around” Khumbu, by climbing a bit up one side or the other of the Western Cwm, on the way to Camp 1)

  3. Yunhyong Kim says:

    Today David Breashears (who climbed the Everest several times) gave a presentation about the melting glaciers at the Microsoft Faculty Summit 2012. JUst thought you might be interested. The images documenting some of the changes are on this website:

  4. John Baez says:

    Tour the southern approach to Mount Everest in this 2-gigapixel image created by David Brashears.

  5. […] Grylls details life at the various camps (Base Camp and Camps 1-4), trekking through the Khumbu Ice Fall, including his harrowing near-death hanging by a rope incident. It can happen to anyone, even to […]

  6. John Baez says:

    Listen to this:

    Avalanche sweeps 12 Sherpas off Mt. Everest, Weekend Edition, National Public Radio,19 April 2014.

    The climbers were on the south side, which is the route that originates in Nepal and goes up the Khumbu Glacier to the South Pole then on to the summit. They key point on this is climbing up through the Khumbu Icefall, and this is a stretch of glaciers that tumbles over a drop. And it’s sort of like a river rapids, if you can imagine, but ice. And so there’s blocks, and there’s a lot of objective hazards. And it’s the most dangerous part on the route as you go towards the summit.

    And in this case, we had Sherpas that were carrying loads through the icefall. And one of the hanging glaciers to the east of the climbing route, hanging off the west shoulder of Everest released, and then that avalanche of ice blocks is what took the lives of the Sherpas.

  7. animalgeeks says:

    Reblogged this on Animal Geeks and commented:
    As a kiwi, Mt Everest has always featured in my conscience, I have been doing some research, trying to understand the dangers at the Khumbu icefall. I found the videos in this very helpful.

  8. Larry Martin says:

    Who do I contact about licensing the Everest Route map for a kids’ book?


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