Mountains

Cho Oyu Expedition: Kathmandu to Lhasa

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Lhasa, Tibet, China – 12,065’

The expedition to Cho Oyu is in full swing, and I’m happy to report that the team is in good health and high spirits.  Well to be honest, we’re not that lively since most of us, myself included, are still addled by jetlag.  (Lhasa is on Beijing time, 12 hours ahead of EDT, though Cho Oyu basecamp will be on Nepal time, 9 hours and 45 minutes ahead of EDT.)  Despite the listless atmosphere that permeates dinner, we’ve gotten to know each other a bit and are settling into society that will be our only company for our four weeks on the mountain.

On Tuesday, after nearly twenty-four hours of travel, I reached Kathmandu from New York City.  The frenzy of preparing and packing and traveling melted away, and my world got smaller.  Mountaineering requires an intense focus on the elements that will help you sustain your life in an unforgiving and inhospitable environment.  In the months leading up to this trip I addressed the foundational prerequisites for success at high altitude: implementing and executing a training regimen, repairing or purchasing gear, and researching the types of challenges I am likely to face.  Now in Nepal, it was time to focus on the minutia that would continue to sustain me for the expedition, whether purchasing a spare watch battery or a calling back home.

Kathmandu Streets

For two days I wandered the frenetic streets of Kathmandu doing these errands, large and small, in an effort to put me at ease so that I could meet the challenges to come.  This quest played itself out on a maze of cobble stone streets that resemble those of Florence with a few notable differences:  the ubiquitous clothing stores hawk knock off climbing gear, not the dernier cri; the scooters, while just as plentiful as in Italy, contribute to a persistent noxious cloud of exhaust and dust; and, of course, Catholic iconography has been replaced with that of Hinduism and Buddhism.

The humid, smoggy frenzy of Kathmandu was reluctant to release us from its grasp when our departure was delayed for three hours due to weather.  Once airborne, our flight path took us to the east where we saw the summits of Cho Oyu, Everest, Lhotse, and Makalu projecting above the tide of the monsoon clouds.  With their passing, we turned north, following those clouds on their march towards the Tibetan plateau and soon descended towards Lhasa in the province of Ü. 

The Himalayas

Lhasa immediately defied my expectations.  While my mind was filled with images of a pastoral, pious town, I was greeted with a modern Chinese city of 500,000 people.  The well-manicured highway took us past neon lights and sprawling suburban apartment buildings, demonstrating the success of the Chinese’s modernization efforts since they assumed control of Tibet in 1959.

Norbulingka

Our visit is concurrent with the Shoton Festival, which has brought thousands of pilgrims to the monasteries and temples of Lhasa to prostrate themselves and ask for favors and good luck for the coming year.   We observed these rituals during a visit to Barkor Square in old town.  Our exploration of the Jokhang, the most important temple in Tibetan Buddhism, took us through winding passages lit only by yak butter candles, which produced a miasma which nearly overwhelmed me on occasion.  Thereafter we visited the impressive and imposing Potala Palace, the winter enclave of the Dalai Lama and historical seat of the Tibetan government.  The Potala is a short drive from the Norbulingka, the Dalai Lama’s summer retreat, where picnickers enjoyed traditional Tibetan opera and explored the gardens and forests around the palace.  We finished our tour of Lhasa with a trip to the Sera Monastery.  Rock paintings of Buddhist icons adorn the hills above the monastery, and we tried, and failed, to make sense of the structure of the debates in which Sera’s monks were engaged.

Today we begin our drift towards the boundaries of civilization.  A six-hour drive will take us through the Tsang Province to Shigatse, a town of 80,000, where we will rest and continue our acclimatization.

The Deadly Power of the 2015 Everest Avalanche

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The 18 deaths on Everest are a small fraction of the 5200+ fatalities across Nepal due to last Saturday's earthquake.  The tragedy of the avalanche at Everest Base Camp is dwarfed by the catastrophe facing the residents of Nepal's major cities.  In the next few weeks, when the Western climbers return to the comfort of home, Nepalis will continue to reel from the destruction, recovering bodies of those who perished and beginning to rebuild the vast tracts of the country that lay in ruins.  If you've been moved by the stories of the destruction in Nepal, please consider donating to the relief efforts.  Both the Huffington Post and Charity Navigator have a useful index of charities providing earthquake-related aid in the region.

For the last five weeks I've been checking the International Mountain Guides (IMG) Everest blog with religious devotion.  Until a few days ago, Luke Reilly, my guide for my mountaineering expedition to Ecuador in January, and Nic Dumensil, a fellow climber on that Ecuador trip, were on Everest gearing up for a summit attempt.  Through blogs and Facebook feeds, I followed Luke and Nic as they acquired climbing permits in Kathmandu, trekked across the Khumbu Valley, climbed Lobuche to acclimatize, and settled into base camp.  It was exciting to read the dispatches and cheer them on from afar, but with Saturday's 7.8 magnitude earthquake and the resulting avalanche, my buoyant ritual became a grim vigil.  Nic and Luke are safe, as is the entire IMG expedition, but 18 other climbers are dead and many more are critically injured.  All the Everest climbing expeditions are retreating back towards Kathmandu, which is itself a difficult proposition because much of Nepal's infrastructure has been destroyed. 

Everest 2015 Avalanche Facts
Serac Size1100 ft x 300 ft (330 m x 92 m)
Serac Weight1.4 million tons
Serac Impact Velocity180mph
Energy Released2.0 kilotons of TNT

I have read and re-read every report from the last few days, attempting to make sense of the violence endured by the climbers.  The devastation simply didn't add up to me.  Mountaineers only make camp in locations that are shielded from hazards such as rock fall and avalanches, and the location of Everest Base Camp is a time-tested safe haven amid the chaos of the Khumbu Glacier.  Make Hamill, an IMG guide, verifies this in his account to National Geographic:  "[I]n the middle of the expansive U shaped Khumbu Valley, we feel safe, buffered by lateral moraines and ice ridges a half a mile wide."  So how did an avalanche surmount the ridges with enough energy to create such devastation?  The first clues came for me in this video:

Video from Everest Base Camp of the powder cloud and gust front of the 2015 Everest avalanche

This wasn't your typical avalanche.  Most avalanche fatalities are due to asphyxiation due to burial (source), but most deaths in this avalanche were due to trauma.  Sure the video shows a powder cloud, but photos of the aftermath of the avalanche only show a dusting of snow on broken tents and scattered equipment.  What's different here is that a blast wave, and not a tide of snow, caused the destruction.  You can actually see evidence of this in the video:  Notice how the prayer flags languidly hang from their tethers (before 0:18 in the video) only to be drawn horizontally by the gust front (0:22 and later) as the avalanche approaches.

According to first-hand accounts, this "avalanche" was spawned when a tenuously perched serac broke free from its ridge and plummeted over 2300 ft (700 meters) to the valley floor.  The photos on the the IMG Everest Blog (here and here) show the serac ("ice cliff") that caused all this destruction.  When the serac hit the valley floor, the energy released caused a shockwave, which rocketed 1.9 km (1.2 mi) towards base camp, over the protective walls of rock and ice that normally shield the camp from avalanches and rock falls.

So what is a serac?  Perhaps not surprisingly, "serac" is a just fancy word for a beautiful chunk of ice that will eventually break loose and hurtle downhill.  Seracs are usually seen at the terminus of glaciers or wherever a glacier flows over a ridge or convex feature on a mountain.  Once a section of ice detaches from the main body of the glacier, the ice becomes a serac.  Thereafter, mechanical stress - due to glacier movement, snow loading, or vibrations caused by human or seismic activity - or melting due to solar heating can cause the serac to break loose and hurtle downward.  Below you can see a photo I took on the Nisqually Glacier of Mount Rainier in 2013.  You can see seracs in the top center of the photo which will eventually break loose and join the pile of rubble in the center of the photo.

Seracs on Mount Rainier, 2013 (Patrick Mauro)

Based on a crude analysis of the IMG photos, the serac measures 330m (1100 ft) in length and 92m (300 ft) in height.  Approximating the serac as a triangular prism, the ice in the serac weighs 1.3 billion kilograms or 1.4 million tons.  Using simple conservation of energy equations, released from a height of 700m (2300 ft), the ice fall would impact the ground at 180 mph (80 m/s) with an energy of 9.0 trillion joules, or 2.0 kilotons of TNT.  (In the rarefied atmosphere of the Khumbu Valley, energy lost due to drag is insignificant.)  The energy released is equivalent to 66% of the destructive power of the Halifax Explosion, which killed 2000 people, and 14% of the Little Boy atomic bomb dropped on Hiroshima.  It's no wonder now that the avalanche was so deadly and a miracle that more people weren't killed.

There have been some incisive editorials in the last few days challenging the wisdom of mountaineers to attempt a mountain as dangerous as Everest.  Explaining why climbers challenge themselves in these deadly environs is a complicated task, which I'll leave for a later time.  For now, consider that 18 people died when the equivalent of a tactical nuclear weapon was loosed only a mile away from them.  Imagine the terror of those in areas closer to the epicenter of the earthquake, and the helplessness the survivors must feel as they try to recover from this disaster.  I, for one, have contributed to the relief efforts in Nepal, and if you feel so compelled, check out the links at the top of the article for a list of charities involved in the recovery efforts.