WHICH IS THE HIGHEST MOUNTAIN IN THE WORLD ?
Results of the Ev-K2-CNR 1987 Expedition
ON 7-8 MARCH 1987, the New York Times and radio and television networks and the principal Italian newspapers reported that K2 was the highest mountain in the world, i.e. 8859 m which makes it [eleven metres higher than Everest.
This sensational announcement resulted from the news of measurements made by Prof. George Wallerstein, an astronomer at I he University of Washington. In this operation, Prof. Wallerstein Bled one of the most modern pieces of equipment, which works via Digitals transmitted by certain artificial satellites.
In the course of a chance meeting on 11 April with Prof. Luigi Bernardi, president of the CNR (National Research Council) I suggested sponsoring an expedition to remeasure the heights of K.2 and Everest in situ, using identical equipment. This suggestion met with instant approval.
I got down straight away to making an initial rough draft for the Organization of the expedition.
Scarcely more than a week later, I received a telephone call from Agostino Da Polenza in Bergamo. This mountaineer was the first Italian to scale the north face of K2, with the Santon expedition in1983; he now runs a kind of mountaineering tourist bureau, which in organizes climbing expeditions to peaks of 8000 m. Agostino wanted to shed some light on the possibility of measuring the height Of K2. I then told him about my project, and the following morning he dropped in at Milan to meet me.
This was the beginning of a fruitful partnership between the two of us, and it was at this point that preparations for the expedition started getting underway in earnest. Speed was essential, for it was also imperative not to take up too much of the expedition members time, and to keep costs down to a minimum.
At this point I should remind you that the traditional altimetric heights of 8611 m for K2 and 8848 m for Everest were obtained with traditional equipment and measuring systems about a century ago. These measurements were carried out by the Survey of India and at that, time, more precise measurements than these could not have been made. In order to carry out the measurements, it was necessary to get hold of equipment known by the initials GPS (Global Positioning System). In the first instance, I got in touch with the Military Geographical Institute, who seemed willing to help out, but I was subsequently informed that for the moment they did not have this equipment at their disposal.
This news meant that I urgently needed to find another organization who might be in a position to supply us with the equipment and personnel to perform the measurements. This was by no means an easy task, since, whatever door I knocked at, I always came away with a negative response. This was essentially due to the fact that these organizations did not actually have GPS available. A whole month went by in this fashion.
Finally, at the beginning of June I managed to find a private organization of Padua which was the only body in Italy that not only owned two operational GPS systems, but also had personnel trained to use them. Negotiations were swiftly concluded; not, however, without considerably increasing our financial commitment. While the society's technicians, under the direction of Prof. Alessan-dro Caporali - a lecturer at the University of Padua, went off to the Dolomites to practise with the equipment, Agostino Da Polenza took advantage of the fact that at that time he had the job of accompanying a mountain-climbing expedition to Nanga Parbat in Pakistan to get in touch with the authorities of that country to request the use of two military helicopters in service on the borders, in order to get quickly to the operative base camp of K2 on the Baltoro glacier, bearing in mind that the border between Pakistan and India, which is still garrisoned by troops, runs along the crest of the mountain. In making these approaches, we were rendered assistance by General Omar Ali Mirza, President of the Pakistan Alpine Club, who was taken on as a member of the expedition.
As far as the measurement of Everest was concerned, the logistical problem appeared to be more straightforward than had been foreseen. This was due to the fact that the mountaineer Renato Moro, who has just returned from leading an expedition to Everest, informed me that the base camp, at a height of 5300 m on the Tibetan slope near the monastery of Rongbuk, could actually be reached by motor vehicle, and he offered to accompany the expedition himself. Therefore, in view of the lesser difficulties involved in carrying out this operation, I decided to give precedence to the measuring of Everest, and on 28 July the expedition, with Agostino Da Polenza as guide, set off for Kathmandu.
The expedition party, consisting entirely of unpaid volunteers, was made up ten members; among them three technicians, one doctor, one journalist, three alpine guides and one cine-photographer.
As for myself, I intended to step in only if it should turn out that my presence were required, as did in fact happen during the course of operations in Pakistan.
After the expedition had set off for Kathmandu, I received no further news from them, until on 10 August came the long-awaited telephone call informing me that the measurement of the height of Everest had been completed in magnificent weather conditions, and that all the members of the expedition were already making preparations to leave for Pakistan.
I experienced a considerable sense of relief on hearing this news, after the worries that had put me under pressure so much of the time during the preparatory phase of the expedition. At the same time, I clearly felt that the trust I had placed in my men, who were engaged in an operation which was far from easy, had been more than merited. This assured me that the Pakistan operations, although accompanied by even greater difficulties to be surmounted, Would succeed in completing the scientific programme within the Projected time of about one month. And so, on 15 August the expedition party disembarked at Islamabad, the capital of Pakistan, and got ready to start off again for the Karakoram. That evening, however, Agostino Da Polenza rang to inform me that my presence as leader of the expedition was required, to resolve certain logistical problems. However, I could not leave Italy soon, so I sent a telegram to say that I would arrive the following week. So it was , with the help also of General Mirza, the entire expedition party left Islamabad and drove to the oasis of Skardu in Baltistan.
There, they had some difficulty in setting off again in the military helicopters for the Concordia base camp on the Baltoro glacier, on account of bad weather. In the end, however, one of the helicopters managed to transport just the operators to a point near Urdukas, the base camp of the Italian expedition in 1929. From there they continued on foot to Concordia. Here once again luck was on our side since, thanks to the magnificent weather, Prof. Caporali's team was able to complete the measurement of K2 and other two peaks in only four days. After this the whole expedition party returned to Skardu and from there, 29 August, they transferred to Islamabad, where I had already been for a few days.
I cannot express how happy I was that morning when I met up with the members of the expedition party on their return from Baltoro! They, too, were jubilant, and this was also because they had the clear feeling that they had completed in full the task that had been assigned to them, and had done so within the time limits scheduled.
The entire expedition party left Pakistan with their burdensome luggage and arrived in Milan late in the afternoon on 30 August. At the airport Prof. Rossi Bernardi, President of the CNR, was waiting to greet the party; he congratulated the travellers returning from their long journey on fully attaining the goals of the expedition in record time, that is the space of about a month, using the most modern equipment to measure the heights of Everest, the highest mountain in the Himalaya, and K2, the highest mountain in the Karakoram.
With the operative phase of the expedition thus concluded, it was time to turn to the matter of processing the data that had been gathered and carrying out various checks to ensure maximum precision in the results obtained from the measurements.
As I pointed out earlier, the official altimetric heights of K.2 and Everest were originally given as 8611 m and 8848 m respectively. Since then other calculations have been made, often with disputed or debatable results, so that they do not actually justify any substantial modification to the original figures. What is innovatory about the measurements carried out by our expedition lies in the fact that for the first time, the heights of the mountains were calculated practically simultaneously using the same measuring equipment, which, as I said before, was the very best available at the present time. The altitudes of the two mountains, and those of Falchan Kangri (Broad Peak) and Gasherbrum IV, which are visible from Concordia, can all be measured in relation to the same plane of reference, established independently of sea level and known as WGS 84 (World Geodetic System 84). This means that the heights of the mountains can be directly campared with strict accuracy. This is something which, in the past, using traditional techniques, was not possible.
The equipment used consists essentially of an electronic diastimeter theodolite and a pair of GPS satellite receivers of the latest generation. As it is known the theodolite allows us to measure horizontal and vertical angles with the greatest accuracy, allowing for atmospheric turbulence. The diastimeter with infrared rays incorporated made it possible to calculate, to a precision of some millimetres, distances of up to three or four kilometres. The new GPS technology is based on the use of the USA Navstar satellites, designed to provide a service for positioning in navigation. The satellites describe orbits at a height of 20,000 km. for periods of about twelve hours.
These satellites transmit coded radio which, once they have been processed by the ground receiver, allow one to obtain, within a short time and from any point of the earth's surface, the exact location (longitude, latitude and altitude) of the instrument's antenna.
When two of the receivers are used in conjunction, the accuracy of the measurements is far greater. The measuring is then done in two distinct phases. In the first phase, the altitude of the base camp in relation to the plane of reference is determined by observing the satellites. In the second, the altitude of the mountain's summit in relation to the base camp is determined with the theodolite, lining it up from different points. The absolute height of the peak is thus the sum of these two terms: the height determined by GPS and that obtained by theodolite, subject to appropriate corrections for the earth's curvature and atmospheric refraction. The most technologically innovative aspect of GPS lies in the fact that when two or more antennae operate at the same time, even at relative distances of several kilometres, levelling and triangulation with precision become considerably more rapid and reliable than with traditional techniques. And now it is time to let the figures speak for themselves. Let us begin with K2, which presents fewer problems.
It was Colonel Montgomerie who, in 1856, measured the heights of the peaks of the Karakoram range from Haramukh (4877 m) 212 km away, and noticed that one of the peaks towered above all the others, he immediately informed his assistant. As it was the second he had measured, he gave it the number 2, prefixing it with the initial letter of the word Karakoram: and so the abbreviation K2 came about.
Its height was measured from another eight stations at distances ranging from 94 to 220 km, and the average of these measurements came to 28,250 feet, i.e. 8610.60 m. Various corrections were subsequently made, but the above figure was consistently maintained, and in most cases rounded up to 8611 m.
Let us now to Everest. I would mention in passing that it is named after the Englishman George Everest who, in 1830, reorganized the Survey on India and in 1841 completed the geodesic grid of the Himalayan arc.
The first measurements of the height of Everest were made between 1849 and 1850 from eleven stations situated at distances of between 94 and 191 km. The average of these measurements was calculated as 29.141 ft i.e. 8882 m, give or take 5-13 m, though the figure adopted on topographical maps and in publications at that time was 29,028 ft i.e. 8847 m, rounded up to 8848 m.1 Although some minor adjustments were subsequently put forward, the height that has been most widely accepted up till now has always been the one indicated above.
At this point, let us finally look at the results of the measurements that we made in August 1987.
In the case of K2, the height of the summit, after various computer corrections, came to 8616 m give or take 7 m. It is thus 5 m more than that obtained by Col. Montgomerie over a century ago.
1. The original height of Everest computed upto 1852 was 29,002 ft. In 1906, using more accurate values for refraction, deflection of the vertical and the geoid, it was averaged out at 29,141 ft. The current height of 29,028 ft (8848 m) was established in the SO1 Technical Paper, No. 8 (1954) by B. L. Gulatee.-Ed.
In addition to K.2, our expedition measured another two peaks, Falchan Kangri (Broad Peak) and Gasherbrum IV. Below are-given the height that we obtained, with the traditional figure alongside:
Falchan Kangri .., ... 8060 m (8051 m)
Gasherbrum IV ... ... 7929 m (7925 m)
As for the Everest, the height arrived at from our measurements is 8872 m, give or take 20 m; 24 m greater, therefore, than the previous figure.
All the figures we obtained show greater than the traditional ones, with differences ranging from 24 m for Everest, to 4-9 m for K2, Falchan Kangri and Gasherbrum IV. A comparison with the older measurements show that 8872 m, the orthometric height of Everest we have determined is closer to that (8882 m) measured in 1905 from the hills using a coefficient of refraction of 0.05, or to the value 8852 m deduced in 1931 by De Graaf Hunter using a refined model of refraction to the value (8848 m) usually given in the maps or the value (8840 m) determined by Waugh. This latter value was felt too low already in the paper by the Survey of India.
The uncertainty of our value for Everest is somewhere between 20 and 30 m, and is due primarily to the performance of the GPS and to the local profile of the geoid. The orthometric height determined for K2, is slightly higher than that, 8610.6 m, measured by Col. Montgomerie, yet not enough to confirm Wellerstein's preliminary observation. The estimated uncertainty is 7 m and 17 m. Because the height increase is also marginal for the nearby mountains, the officially quoted heights can be considered as firm.
The main objective of the Everest-K2-CNR expedition was first and foremost to establish whether K2 was in the fact higher than Everest, as claimed in the international press on the basis of Wallerstein's measurements on K2. This was the primary question and I believe it can be said to have been settled once for all.
The second objective was to find out how much higher Everest is than K2 in term of size. From the measurements we took, the answer would appear to be that the difference is 250 m, i.e. not greatly different from the traditional measurement of a hundred years ago of 237 m.
The third objective was to establish the current height above sea level of Everest and K2, a problem which is closely linked to the previous one. This third objective was only achieved with the approximate measurements owing to limited time available for geodetic operations at the locations for the reasons explained in the first part, and owing to the need to supply answers in a fairly short space of time to the numerous and pressing request I received from all over the world. The results given are those obtained from the instruments used, i.e. a preliminary elaboration of the data. I should state at this point that another expedition will in fact be needed to give full definitive answer to these third objectives.
Although our heights cannot be assumed as definitive it is symptomatic that all the figures we obtained show greater heights than the traditional ones with differences ranging from 4 m ^or Gasherbrum IV, to 24 m for Everest. If we assume provisonally that there have been no errors in the old and recent measurements, the area Of K2 must have risen in the last century at a rate of 2.8 cm a year, and that of Everest at a rate of 1T.5 cm. In the light of what is currently known, these figures seem to be excessive, at least with regard to Everest.
How can we explain this problem?
The most plausible explanations are either that there has been n sudden elevation of the mountains in the last century, or the measurements were imprecise. The most logical conclusion seems to be to attribute the difference partly to one factor, partly to the other.
At this point, I should like to mention an experience concerning (he Everest area. Some years ago, toward the end of an excursion across the southern Tibet in the company of some Chinese colleagues, not far below the Yagru Shohn pass at a height of 4950 m, some fragment of bone were pointed out to me. They occurred within a sandy layer of lacustrine origin, turned up in clearing the road. They were in fact fossil bones of Hipparion, an ancestor of the horse, of which remains have been found on the southern slope of the Himalaya only about a thousand metres above the sea level.
What does all this mean? It means that in the last two million years, this area has risen 4000 m at a rate of about 2 mm a year. The figure seems to be significant, but it is too small if we compare it with the figures given for K2 and particularly for Everest.
The problem may by solved with further investigations, particularly in the Everest area, where I hope to be able of organising further expeditions also devoted to tackling other problems of geodetic, geophysic and geologic interest in connection with those of my previous expeditions in the Karakoram and Hindu Kush mountain ranges.