October 5, 2011


Loben Expedition - undertaking an exploration trip to Tibet via Simikot in the October month of 2011.
A team of 06 members along with our experience trek crews take off to Simikot on 2nd of October to trek all the way to Tibet border. After entering Tibet from Taklakot border they will head toward Tsaprang region to explore Guge Kingdom. After the exploration of Tsaprang region the team will head back to Lake Manasorovar to trek around Mt. Kailash. The team will then drive to Everest Base camp and will concluded their trip by flying out of Lhasa

Pictures to follow soons:

The team : 


Loben Expeditions - Shishapangam South Expedition 2001 Autumn from September 08 to October 15

For detail check out : http://seblefou74.wordpress.com/

September 5, 2011

Loben Expedition team felicitation

Loben Expedition Team felicitated by Government of West Bengal for organizing 2nd successful West Bengal Mt Everest Expedition

June 25, 2011


Third Pole, club of Ukraine



Самонадеянность - гвоздь в крышку гроба

May 23, 2011

Mamata Banerjee gets towering gifts – from the Himalayas

Kathmandu, May 21 (IANS) When Elizabeth II was being crowned in London in 1953, the celebrations received an extra boost with the news arriving in London that Mt Everest had fallen with Edmund Hillary and Tenzing Norgay Sherpa becoming the first men to reach its 8,848-metre summit.

In an almost parallel situation, as feisty Trinamool leader Mamata Banerjee took oath of office and became the first woman chief minister of West Bengal, the mighty Himalayas bestowed gifts galore on her with four climbers from West Bengal conquering towering peaks and enhancing the image of her state.

Two men from Joypurbil in West Bengal’s Howrah district made the state proud Saturday by summiting Mt Everest as an individual initiative.

Rajib Bhattacharya, a 38-year-old small-time businessman from Howrah, walked tall as he stood on the world’s highest peak at 9.55 a.m., accompanied by his mountain guide Phurbu Sherpa from Nepal.

About two hours later, his travelling and mountaineering friend Dipankar Ghosh, 46, also reached the summit with his Sherpa guide Kama Sherpa, said Loben Sherpa of Loben Expeditions.

The number 13 proved lucky for the two Howrah heroes who are part of a 13-member expedition that also includes climbers from Australia, Japan, Brazil, Denmark and Sweden.

Sharon Cohrs, a 40-year-old Australian who is part of the expedition, will become the first breast cancer survivor to ascend Mt Everest. She is climbing to raise funds for research as well as raise awareness about the killer disease.

Earlier, a double bonanza for West Bengal came from another pair of bravehearts from Krishnanagar, Basanta Sinha Roy and Debashish Biswas.

Roy, 50, and Biswas, 40, summited Mt Kangchenjunga, the third highest peak in the world after Mt Everest and K2.

‘They reached the 8,586-metre summit Friday, the day Mamata Banerjee took her oath as the new chief minister of West Bengal,’ Loben Sherpa said.

‘It was a great gift for the new government with the feat enhancing West Bengal’s image as a land of intrepid climbers and adventurers.’

It was all the more remarkable since the duo had summited Mt Everest last year.

While Sinha Roy is an employee of Punjab National Bank, Biswas is an Income-Tax official in Kolkata.

Though after their achievement last year, they were felicitated by the then Left Front government in the presence of erstwhile chief minister Buddhadeb Bhattacharya, the two men had raised the funds needed for the expedition mostly on their own, taking personal loans that they could pay off only this year.

It has been an incredible mountaineering year for the individual Indian climber with 17 people trying to summit Mt Everest on their own and many succeeding. While Haryana leads the way with the majority of the aspirants from there, Orissa, Jharkhand and Arunachal Pradesh have also made their mark.

May 20, 2011


Loben Expedition North Everest Expedition member  Anny Kvithyll with Ang Tashi Sherpa and Nagda Sherpa left for summit from North side last night. 
Confirmation of her summit will be reach to us by today evening as we are unable to have satellite connection to ABC of Everest North. 


The team of two members Rajib Bhattarcharya and Dipankar Ghosh along with Climbing Sherpas- Furba Sherpa, Karma Sherpa and BC cook Buddhi Magar become the Second Bengal Civilian team to  conquer Mt. Everest this morning. 

As per Buddhi Magar over BC cook: Rajib Bhattarcharyya and Furba Sherpa reached the summit of Mt. Everest at around 10:05 a.m. Dipankar and Karma reached the summit at around 11:20 a.m.

They are all fine and are on the way back to south summit. 

They stared climbing from Base camp for camp II on the 18 of May spend night at camp II  on 18th May, reached Camp III on 19th May. They reached south col on May 20, 2011 at around 11: a.m. and after a rest of less than 10 hours they started for final summit bid in the night of 20th May at 09:00 pm.

Bengal 2 scale Kanchenjungha

Saturday , May 21 , 2011- The Telegraph, Kolkata, India

Darjeeling/Behrampore, May 20: On a day Mamata Banerjee climbed to the seat of power in Writers’ Buildings, Basanta Singha Roy and Debashis Biswas became the first Bengalis to scale Mount Kanchenjungha, the third highest mountain in the world.

Basanta, 50, an employee with a nationalised bank, and Debashis, 40, an income-tax official, climbed the peak, braving strong winds and unstable weather. The duo stood at the top of the mountain at 7.40am, along with three Sherpa brothers, Passang Pusur Sherpa, Pemba Chhoti Sherpa and Ang Tashi Sherpa.

Loben Sherpa of the Kathmandu-based Loben Expeditions told The Telegraph via e-mail that the five-member team had started the ascent from the summit camp about 6am today. “At 7.40am, Pemba informed the base camp over walkie-talkie that they had reached the top and all of them were fine. This was relayed to me via sat phone by Lila Rai from the base camp around 7.50 am,” said Loben. 

The expedition was organised by Loben Expeditions.

“Basanta and Debashis were the first from Bengal to conquer Mt Kanchenjungha. They were also the first civilian Bengalis to summit Mt Everest (29,029 feet) in May last year,” said Loben. He also said the three Sherpas were the first brothers to have climbed the peak together.

Both Basanta and Debashis, who work and stay in Calcutta, are members of the Mountaineering Association of Krishnagar in Nadia district. Even though people were glued to the television sets for Mamata’s swearing-in at Raj Bhavan, there were scenes of celebrations in Krishnagar. Members of the association, who received the news at 7.45am, announced the feat to the residents of town through loudspeakers.

“They had started the expedition from here (Krishnagar) on March 28 and 368 days after conquering Mt Everest, they were on top of Kanchenjungha that stands at 28,169 feet. They had scaled Mt Everest on May 17, 2010. No mountaineers have climbed two peaks in a gap of 368 days,” said Arup Sarkar, a member of the association.

A large number of people came to the association office to offer congratulations.
“There were phone calls also as people felt very happy about the achievement,” said Sarkar. He added that Kanchenjungha was conquered last by a British-American team in 1998.

Basanta and Debashis climbed from the Nepal side of the mountain. Climbing is banned on the other side that falls in Sikkim as the mountain is considered a holy place in the hill state.

Everest South side - update 20-May-2011

Dipankar, Rajiv, Karma and Furba of our second Bengal Everest Expedition reached South Col at 10:00 a.m this morning from Camp III. After a rest of more than 06 hours, the team are now heading toward the summit of Mt. Everest with a target to reach the top by tomorrow morning before 07:00.... Friend and family look forward for good news from the top................ 


Beside strong wind and unstable weather, Loben Expeditions Bengal Kanchejunga Expeditions summit the third highest peak in the world at 07:40 a.m. today. They started climbing from summit camp at 06:00 p.m yesterday and reach the summit at 07:40 a.m. this morning. Pemab walkie -talkie Lila (BC cook) form the the top- they said we are fine and we are all (Basanta, Debasis, Passang, Pemba and Tashi) on the top. Message relay to us at 07:50 via satellite phone from Baase camp by Lila Rai. 

Basanta Sigha Roy and Dibasish Biswas is the first persons to climb Mt. Kanchejunga from Kolkata via South side. They also become first persons to climb Mt. Everest from Kolkata last year with Loben Expeditions.

Passang Futur, Pemba Chotti and Tashi are probably the first three brothers to climb and stood together on  Mt. Kanchenjunga. 

May 19, 2011


Dipankar and Rajiv along with Karma and Furba reached Camp III this morning at around 10:00 a.m. They will be heading toward South Col. tomorrow morning at 06:00 a.m After a rest/sleep for 6-7 hours at South Col. they will start for Mt. Everest summit at around 07:00 p.m. They are expected to reach the summit by 06:00 a.m. in the morning of 21th May. 

May 18, 2011


Basanta, Debasish, Pemba, Passang and Tashi started to climb toward summit but due to high wind and snowfall they had to return back to summit camp. They may try again tomorrow. 

May 17, 2011


Loben Expeditions - Khangla pass and Meshokanta pass team successful cross Khangla pass besides heavy snowfall along with 13 team members from Ukraine, 10 staff and 25 porters. The team is the first one in the season to successful cross the pass, the team however has to alter the idea of crossing Meshokanta pass via Tilicho lake toward Thorong la due to heavy snowfall. Kangla pass is the only pass that access to Nar region via Manang. Nar phu is still very remote region within the close proximity of world famous Annapurna trek.The region of Nar Phu falls between the Annapurna and Larkya pass. 


Loben Expeditions Everest North expeditions: Anny and Sherpas climbed up to 7500m as acclimatization trip two weeks ago and now waiting for route fixed up to summit. Route fixing is under the contract of  Tibet Association of mountaineering. Due to heavy snow and strong wind it is still incomplete. Hopefully all the expeditions sherpa will have join effort to complete this job in next couple of days before the clients start summiting Mt. Everest from North side. Anna, was stuck for two days at Tingri in the middle of nowhere as Everest Base camp was suddenly closed for couple of days, she however manage to get back to Base camp. 

Mt. Everest expedition update- 16 May 2011

Loben Expeditions Bengal Everest team - Dipankar and Rajiv heading for Camp I tomorrow i.e. 17 May along with  Furba and Karma. They will be sleeping in camp I on 17th May and heading for Camp II on 18 May. They are planned to summit Mount Everest on the morning of 21th May 2011. The team had to retreat back to base camp on May 14 from Camp III after strong wind at Camp III and above. "Message from Base camp said :   we are fine and back to base camp due to strong wind we are heading back on May 18 to get to top on the morning of May 21". 


A quick from Mt. Kanchenjunga BC- all the our team (Loben Expeditions Bengal Kanchenjunga Expedition)  heading for Camp II  with a target to reach the summit on the 20th of May. Lila said over phone : sabai thik cha yeaha, sabai team haru May 20 ko summit plan gara ra, camp II ga ko cha. (Everthing is fine here, all team has moved to camp with a plan to summit on May 20. 

May 11, 2011


Dipankar, Rajiv and Karma left for camp III this morning from Camp II. They will sleep at Camp III today and will continue for South Col. tomorrow morning. Furbar will go directly from Camp II to Camp IV tomorrow. Four of them are planned to start for summit tomorrow evening from South Col.   

May 10, 2011


The team members and Sherpa are back in Base camp, they had return back to Base camp after heavy wind on the mountain. The team next plan is to climb from Base camp to Camp III all together with Sherpas (Pemba Chotti, Passang Futar and Tashi) set up summit camp and attempt the summit...... follow more update  

May 9, 2011

Manaslu Korea: Mission Accomplished

(Newsdesk) The Korean 2011 "For Freedom 2011 Manaslu expedition" mission was twofold: find the remains of Yun Chiwaon and Park Haeng Su and summit. Now it has been accomplished.

Last week, Fishtail Air issued a press release stating that the operation had recovered Park Heangsu from Manaslu 6400 meters by Fishtail Air’s AS350 B3+ helicopter.

"Park Haeng Su along with his friend were on their way up to the summit of Mt. Manaslu last year when they experienced harsh weather," said the report. "As a result of a white out they lost their way and called for rescue. Fishtail Air’s immediate search for them proved futile." 
"This year his body was found by the Sherpas and brought down to Camp II. Fishtail Air was once again given the responsibility of recovering the body from camp II to Kathmandu where his family and friends were awaiting for a better farewell."

Today Loben Sherpa, expedition organizer for the expedition shot over further news to ExplorersWeb that Mr. Kim Migaon, Mr. Sanu Sherpa & Mr. Chinjung Bhota made the summit of Mansalu this morning (09 May 2011) at 06:10 a.m.

Loben also wrote that the expedition team found Park Haeng Su at an altitude of 7500 meters. "His body was carried down to camp II with the help of our Sherpa team and brought down to Kathmandu from Camp II (6400m) by Fishtail helicopter," Loben said.

The body will be cremated in Kathmandu on May 13 as per Korean and Buddhist ritual ceremony.

The search is now on also for Yun Chiwaon, Loben said.


May 8, 2011


Just had a text in from Andy and Nick (see below)....unfortunetly its bad news the weather hasn't improved so the guys have had to bail on their attempt and are now on their way back to Kathmandu. 

"Hi Dunk, we've been shut down by unsetttled weather and too much snow up high, its been over 2 weeks since we had the last snow free day, with no chance of getting on the South pillar we tried the easier West ridge but got hammered by the weather. We went a different way to the first ascent team found some very 'exciting' (very scary) climbing. There was way too much snow to make any progress on the upper ridge so bailed next morning. Should be back in Kathmandu in a week Nick and Andy"


News came all the way from the top of Mt. Manaslu that Mr. Kim Migaon, Mr. Sanu Sherpa & Mr. Chinjung Bhota  of "FOR FREEDOM 2011 MANASLU EXPEDITION" successful summit Mt. Mansalu this morning (09 May 2011) at 06:10 a.m.

The expedition main objective was to search the bodies of YUN CHIWAON and PARK HEANGSU, who disappear and died during 2010 Spring Manaslu expedition. The team has successfully searched and found the body of Mr. PARK HEANGSU at an altitude of 7400m. His body was carried down to camp II with the help of our Sherpa team and brought down to Kathmandu from Camp II (6400m) by Fishtail helicopter. Park Heansu body will be cremated in Kathmandu on May 13 as per Korean and Buddhist ritual ceremony.

Rest of the Sherpa team and member are now searching for the body of Mr. YUN CHIWAON   - Loben Sherpa  (Loben Expeditions/Trekking Camp Nepal)


LE Mt. EVEREST -South side
Our Everest team are ready for summit attempt on MAY 14 morning. Team members are at Base camp and leaving for Camp II on May 10. Sherpa (Karma and Furba) reached Camp II today they will continue climbing to Camp IV to set up last camp, before the team arrives 

LOBEN EVEREST Expedition  -North Side

Anna - manage to reach base camp today after she was stuck at Tingri for 02 days. She is now in Base camp - happy and well acclimatize and ready for the summit. Sherpa's of Anna(Ngad and Ang Tashi) has already set up summit camp and now they are waiting for right window for summit bid.  are ready for summit attempt on MAY 13. All members are Base camp and Sherpa went up to Camp III to set up Camp IV for final preparation. Anna will starting climbing from Base camp tomorrow to ABC.
Our Kanchenjunga expedition are going well at the same time - Pemba, Passang and Tahsi went up to camp IV two day back to set up summit camp and will be back to back tomorrow after that the final plan for Kanchenjunga summit will be made. The team of Kanchenjunga can be reach at 008821687701122. 

British Kyashar Expedition: 

Nick and Andy is back to base camp this morning after bad weather and lots of snow on the mountain they will decided whether to continue or not later.  
As per message from Palden

British Kusum Kangaru East Expedition: 
Graham and Ben is heading back to high camp tomorrow after couple of rest day in Base camp. As per 
message from Palden - base camp 

March 15, 2011

Mortality on Mount Everest, 1921-2006: A Descriptive Study

Tuesday, January 20, 2009
(Click here for Research Paper)
Re: 1. Firth PG, Zheng, H, Windsor JS, Sutherland AS, Imray CH, Moore GWK, Semple JL, Roach RC, Salisbury RA. Mortality on Mount Everest, 1921-2006: descriptive study. BMJ 2008; 337: a2654
2. Supplemental Data. Himalayandatabase.com

I was asked by a member of the IMF to submit a brief discussion of a recent medical study performed about deaths on Mount Everest. Some years ago I was in Delhi and was pleased to be able to visit the headquarters of the IMF. I was impressed with the library and the IMF commitment to helping climbers from around the world. I also appreciated the extensive information that was available, data that can help to improve the safety of climbers. In my early years I was a member of the Mountain Club of South Africa; now that I live in Boston I am now a member of the American Alpine Club. I think climbing associations are vital to further the aims of mountaineering, so I am pleased to provide some information to further the IMF’s goals and help improve the safety and enjoyment of climbers.

The original article may be downloaded without cost from the British Medical Journal (BMJ) website BMJ.com, or accessed via the IMF website which has a link to the article. Additional information, which includes more a detailed plot of deaths, deaths at and below base camp, the details and importance of summit times, and a further informal discussion, is available for free online at Himalayandatabase.com.
What did this study examine, and how was it done?
The study set out to examine the circumstances of all deaths on Everest expeditions between 1921 and 2006. We identified all deaths on Everest expeditions by searching the Himalayan Database and expedition books. We then located accounts of these deaths by examining reports in the Database, expedition books, climbing journals, or on the Internet, or by directly contact with witnesses. Four doctors, all of whom had climbed on Everest, classified the deaths using a descriptive classification system. Three had summited Everest; one had turned back at 8300m. All four reviewers had a particular interest in high altitude physiology, and had practical experience in managing high altitude illness. The classifications were then pooled and differences were resolved by consensus. The degree of disagreement between the independent assessments was measured to give an indication of the reliability or certainty of the final classification system. The final results can be found on the website of the Himalayadatabase and in the BMJ article.

We then looked at specific subsets of events. As most mountaineers are interested in what happens higher on the mountain we focused on events above base camps, defined as the last encampment before technical (roped) climbing began. As the majority of summits were via the ‘standard’ Southeast and North ridge routes, during the spring season, and in the last 25 years, we also examined this group in detail. This minimized variables such as season, the differing difficulty of the technical routes, and the changes in expedition styles that have occurred over the decades. We looked at the specific circumstances of the deaths of those that died after climbing above 8000m.
To examine the effect of weather, we used measures of barometric pressure at 9000m obtained from a dataset at the National Center for Environmental Prediction. This has been used previously in studies of weather conditions on Everest.

What were the most significant findings?
For the entire study period, the mortality rate of mountaineers above base camp was 1.3%. Among climbers it was 1.6%, among sherpas it was 1.1%.
Deaths could be classified as involving trauma (objective hazards or falls), as non-traumatic (high altitude illness, hypothermia or sudden death) or as a disappearance (unwitnessed death, body not found). During the spring seasons on the standard routes, most climbers died above 8000m during a summit bid. The death rate on the north was 3.4%; on the south side it was 2.5%. Most summits occurred during good weather windows, and most deaths also occurred during fair weather. When storms played a role in deaths, many climbers tended to die on a single day; however the majority of deaths occurred on days when weather had not markedly deteriorated.
Most mountaineers who died above 8000m died during descent from the summit. Climbers died at a much higher rate during the descent than sherpas. Late summit times were associated with subsequent death. Many developed symptoms suggestive of high altitude cerebral edema (HACE): confusion, loss of consciousness, and a staggering gait. Symptoms of high altitude pulmonary edema (HAPE) were rare in those that died. An common early sign was marked fatigue, as reflected in reports that the mountaineer looked exhausted, the tendency to fall behind other climbers on the party, and a late summit time.
So: Most climbers die during summit attempts, when they are climbing above 8000m. On well-established routes, with relatively few technical difficulties, with most climbers climbing during good weather windows, many of the climbers who died developed confusion and inco-ordination. These symptoms often became debilitating during the descent. Slower climbing speeds and late summit times were early signs associated with subsequent deaths.

While obviously technical difficulties, bad weather, lack of protective ropes, difficulty of rescue and breakdown in teamwork all play roles in deaths at extreme altitude, a significant fatal effect of very high altitude therefore appears to impairment of thinking and co-ordination. Excessive fatigue appears to be an early warning sign.

How did people die above 8000m?
We classified deaths by a descriptive technique. Of 94 deaths of mountaineers who reached 8000m, we classified deaths as those that involved a fall (34%), disappeared (29%), high altitude illness (11%), suddenly death (5%), hypothermia (2%) or we couldn’t decide exactly a single classification (15%) – usually between HACE or hypothermia. We used this technique since it allowed us to classify a very varied series of accounts, of a very varied set of circumstances, in an objective and reproducible way that minimized our own interpretation or bias. From this foundation, we could then examine the deaths in more detail and try to look for factors we speculated might have caused the fatalities. This was therefore a descriptive classification, not necessarily one that demonstrates the underlying ‘cause’ of death
Of these deaths, a large number involved climbers that developed neurological problems before falling or disappearing – confusion or staggering gait. This would suggest that neurological problems were an underlying ‘cause’ of many of these deaths.

How reliable is this classification system?
Since an observer examining an account might read different things into what happened, we used four reviewers, all of who examined the accounts independently of one another. For all 212 deaths during Everest expeditions, there was an initial unanimous agreement for 165 (78%) of classifications. This number does not give a full measure of agreement – if, for example, only one reviewer disagreed on the remainder, this would be less disagreement than if all four reviewers came up with four completely different classifications. So we used a statistical test called the Fleiss Kappa test that measure the degree of inter-rater agreement. The kappa value was 0.63, which implies ‘substantial agreement.’ It is impossible to accurately classify all deaths due to the variability in accounts, the differing circumstances, and the possibility of unknown causes. If one has a classification system that gives 100% agreement, this would probably be too insensitive a reflection of complex events. We felt the measure of agreement reflects the best balance between agreement and uncertainty in a classification system of an uncertain subject matter.

What causes the confusion and loss of co-ordination?
We felt that these symptoms were consistent with cerebral edema (HACE), caused by the low oxygen atmospheric content at extreme altitude. HACE is due to inadequate acclimatization to the low oxygen levels, which results in the blood vessels in the brain leaking fluid into the surrounding brain tissue (edema). Confusion and loss of co-ordination follow. Direct deterioration of the brain’s functioning may also occur, although relatively little is known about this at present.
Hypothermia or extreme cold can also cause these symptoms. In some cases we felt the cold was the primary cause of the symptoms, in others we concluded it was due to HACE, and in some cases we couldn’t determine which was the primary cause. A climber who is incapacitated by HACE will easily develop hypothermia in the extreme cold above 8000m. However we felt it was unlikely that hypothermia was the sole or primary cause of neurological deterioration in most cases.
We also looked for signs of visual disturbances (snow blindness or retinal hemorrhages) that might masquerade as confusion or uncoordinated gait. Although we know that these are significant problems at extreme altitude, we didn’t find evidence to suggest that visual problems were a common primary explanation for the symptoms. We didn’t think the symptoms could be explained by visual disruption alone.
Other physical features associated with extreme altitude, such as high ionic radiation, are not know to cause these effects in the relevant time frame.
We therefore often interpreted the described symptoms as evidence of fluid leaking from blood vessels in the brain, due to inadequate acclimatization to the low oxygen availability at extreme altitude.

Couldn’t the deaths and neurological symptoms on descent simply be due to climbers running out of oxygen?
Running out of supplemental oxygen probably doesn’t help the functioning of the brain. However, we saw similar patterns of mortality in climbers who died while climbing without supplemental oxygen – i.e. most of these climbers died during the descent. This suggests the problems cannot simply be explained by loss of oxygen. In addition, it is not uncommon for climbers to have failures of their delivery sets while climbing up. However we didn’t detect any deaths due to this. We interpreted this as implying that mountaineers developed some problem that heightened their susceptibility to loss of supplemental oxygen. This might include sub-clinical HAPE and/or HACE that is not obvious when oxygen-enriched air is used, but which becomes obvious when the supplemental oxygen runs out.

So is HAPE rare at extreme altitude?
This study suggests that it is unusual for non-survivors to develop florid HAPE. This may be because mountaineers who get HAPE turn back early and survive, because those with severe HAPE are still able to get down and live, because those prone to HAPE get it lower down the mountain, or because the use of supplemental oxygen (which lowers the blood pressure in the lungs) alters the response to altitude. Another caveat is that this study is the first to examine the problems in the ‘death zone’ in detail – perhaps other future studies may have other results. However we detected very few deaths that clearly involved HAPE. So although HAPE may occur at extreme altitude, it was rarely a clear or obvious factor in fatalities.

So how do you tell if you are getting HACE?
Unfortunately once you get HACE you are in severe trouble – your insight is impaired, since you are confused and may not realize what is happening. As you are confused and uncoordinated, it is difficult for other mountaineers to rescue you since they have to physically haul you down the mountain. In the absence of a large team, this is hard to do (but not impossible – organized teams can get even severely impaired climbers down to lower altitude where they can make good recoveries).
The earliest sign seems to be marked fatigue – sense of extreme exhaustion, falling behind the group, and making the summit later in the day.

How late is late? Everyone is exhausted at 8000m – how fast do the individual need to climb?
Unfortunately we don’t have records of what time mountaineers left summit camps at, or what camp they left from on the North Side. There is also no record of the exact oxygen flow rates that climbers used, which will impact on their climbing speed. Almost all survivors make the summit by around noon to very early afternoon. However assuming most leave around 10pm - midnight, this means a maximum of about 12 –14 hours. The risk of death associated with slower climbing speeds and later summit times goes up dramatically after this. Graphs of summits times of survivors and non-survivors are available at Himalayandatabase.com.

In recent years large numbers of climbers make summit bids on the same days. Measuring ascent speed against other mountaineers is another yardstick. Mountaineers who died tended to fall behind the others in their team.

What about other symptoms?
Other early signs of HACE include nausea, vomiting and headache. These symptoms seemed rare in those that died. The precise mechanisms that lead to these symptoms are unknown – one theory is that they may be related to stretching of the sensitive membranes covering the brain as it swells. We speculate that at extreme altitude, the brain does not swell as much before debilitating confusion and loss of coordination set in, so headache and nausea are not reliable early warning signs. However perhaps witnesses simply didn’t report these events, or those mountaineers with these symptoms turned back earlier and survived. Further study will be needed to confirm this.
NOTE: Although this is speculation, it seems that fatal cases of HACE are not reliably preceded by headache or vomiting. Although one might assume that climbers who die are simply victims of their own stubbornness in not turning back earlier, this may not be the case. Rather they mistake the early warning sign (severe exhaustion) for the expected fatigue experienced while climbing at extreme altitude. Warning signs such as headache or nausea may not occur. As HACE sets in, they become confused and lack insight into their condition. Although this study has not proved this (it is very difficult to demonstrate the definite absence of something), this speculation should be considered by climbers at these altitudes.
Couldn’t the late summit time-death association simply be explained by more time at risk of being caught in bad weather?
We were somewhat surprised to see how rarely bad weather played a role in deaths at very high altitudes during the spring. We were able to use weather data collected over years to look at an association of deaths with changes in atmospheric conditions. The most useful marker was barometric pressure, although other weather markers have also been collected. Most summit bids occur in good weather – and most days when deaths occur have reasonable weather too. When the weather does turn bad it can kill a lot of people if it catches entire teams out on the mountain. However the 1996 “Into Thin Air” storms are quiet unusual events. This may be because weather forecasting has improved, and so mountaineers tend to pick the right time to try for the summit.

Is it possible to acclimatize to 8000m?
This study cannot directly address this issue. Certainly the low descent mortality rates among the sherpas suggest that mortality rates amongst climbers could be lower. Because they are employed to place ropes and transport equipment, sherpas tend to spend more time at very high altitudes. But as they have been through a competitive process to win jobs as sherpas, there is a selection bias in this group. Many are born and live at high altitude (Sherpas or ethnic Tibetans) and may have adaptive advantages to high altitude. So it is difficult to tell if they are sending more time at very high altitude because they acclimate better, or if they are better acclimated because they spend more time at very high altitude, or both. Other factors, such as greater climbing experience or the tendency to climb in groups may also play a role. So the ability of lowlanders to acclimate to very high altitudes remains ill defined and needs further work.
Any other notes of caution?
This is a single study – later studies, differing interpretations and advances in the understanding of high altitude physiology at extreme altitude may alter the conclusions mountaineers should draw. A catastrophic event such as a mountaineering death is often the result of the convergence of multiple factors. While we have examined the effect of high altitude illness, other factors play a role in fatalities. The mountaineer should simply use this study as one guide in assessing the many complex decisions that need to be made to ensure safety in high places.
I hope this is of help to Himalayan mountaineers. The Himalayas are the highest range in the world, and the challenges of extreme altitude are unique to this area. An understanding of the events in the ‘death zone’ is essential to safe mountaineering.
Thank you for allowing me the opportunity to post on your website. Happy and safe climbing!

Paul Firth, MBChB
Department of Anesthesia and Critical Care, Massachusetts General Hospital
Boston, Massachusetts, USA

February 25, 2011