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The precautions to be taken against a direct strike consist in getting away from the summit or ridges, and, if this is impossible, to get as close to the rock as possible without lying down. A squatting position with head low is ideal. Any pinnacle in the vicinity that is five to ten times the height of the squatting position will give lightning-rod protection.
From a study of potential distribution on an idealized mountain (see figure) several important theoretical conclusions may be reached.
Since the potential lines are farther apart near the base, it is apparent that it is safer near the base. The long ledge is safer than the sloping ridge near it. The vertical portion of the ridge conducts large currents. Thus, one may conclude that the steeper the rock, at any given height above the base, the more dangerous its ground current.
The protection from ground-current injury should consist of getting on rock with the least slope available. The climber should be sure that he stays as far from the wall as possible to minimize the danger of a discharge from the wall to the body. One point of contact with the rock should be the maximum. The danger of rappelling is immediately apparent, as it automatically gives the climber two points of contact with a very great potential difference.
Combining the precautions against both ground currents and a direct strike, we find that the best position would consist of squatting with the head down and feet together in the middle of a wide ledge or as gentle a slope as is available. Ice ax, crampons, pitons, and other sharply pointed objects should be some distance away. Possibly the ice axes could be placed ferrule up to form crude lightning rods (especially if the handle is wet or its conductivity is otherwise improved, e.g., by wire).
The cave shown is similar to the one in which an accident on Bugaboo Spire took place in which lightning indirectly caused the death of two climbers and nearly killed two others. The potential gradient is seen to be high in the vicinity of the cave, owing to the steepness of the floor and sides. It is presumed that this is the reason for the injury and deaths, inasmuch as a direct strike inside the cave is highly unlikely. All were leaning against the rock at the time of the discharge, which would account for the burns that they suffered on the back and legs. From an analysis of this situation, it would seem that a position on the somewhat level portion of the ridge would have been safer.
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