Italian Expedition to Tibet and Pakistan to Conduct Further Observations on the Altitude of Mount Everest and K2. (Professor Ardito Desio, who organized and was in overall charge of the group that undertook the new measurements, has kindly supplied the Editor with a report from which we print the following excerpts.) Renato Moro informed me that the Base Camp at 5300 meters on the Tibetan slope near the Rongbuk Monastery could actually be reached by motor vehicle. Therefore I decided to give precedence to the measuring of Everest. On July 28 the expedition set off for Kathmandu. (It is assumed that the party traveled directly to the Everest Base Camp via the Kodari Road.—Editor.) The field party was made up as follows: Professor Alessandro Caporalli of the University of Padua in charge of geodesic measurements, Engineers Lionello Lavarini and Claudio Pigato, assistants to Caporalli, Dr. Attilio Bernini, physician, Dr. Mino Damato, journalist, Agostino Da Polenza, mountain guide, Kurt Diemberger, cine-photographer, Renato Moro, mountaineer, and Soro Dortei, mountain guide. I received no further news from them until on the tenth of August came the long-awaited telephone call informing me that the measurements of the height of Everest had been completed. All members were making preparations to leave for Pakistan. There was some difficulty in setting off for the Concordia Base Camp on the Baltoro Glacier. One of the helicopters managed to transport just the operators to near Urdokas and from there they continued on foot to Concordia. Professor Caporalli’s team was able to complete measurements of K2 in only four days.

The equipment used consisted essentially of an electronic diastimeter theodolite and a pair of GPS (Global Positioning System) receivers of the latest generation. The theodolite allowed us to measure horizontal and vertical angles with the greatest of accuracy, allowing for atmospheric turbulence. The diastimeter with infra-red rays incorporated made it possible to calculate to a precision of some millimeters distances up to three or four kilometers. 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 kilometers for periods of about 12 hours. These satellites transmit coded radio signals which, once they have been processed by the ground receiver, allow one to obtain, within a short time and from any point on 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 in relation to the plane of reference is determined by observing the satellites. In the second, the altitude of the mountain’s summit is determined by the theodolite, lining it up with 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 operated at the same time, even at a relative distance of several kilometers, leveling and triangulation with precision become considerably more rapid and reliable than with traditional techniques.

It is time to let the figures speak for themselves. Let us begin with K2, which presents fewer problems. The height of K2, after various computer corrections, came to 8616 meters, plus or minus 7 meters. It is thus 5 meters more than the height obtained by Colonel Montgomerie of the Survey of India over a century ago. In addition to K2, our expedition measured another two peaks. Our figures are followed by the traditional figures in parentheses: Broad Peak 8060m (8051m): Gasherbrum IV 7929m (7925m). As for Everest, the height arrived at from our measurements is 8872 meters, plus or minus 20 meters. This is 24 meters greater, therefore, than the figure previously considered the most valid.

Ardito Desio, Italy