The panorama of the Aletsch Glacier and the Fiescher Glacier in the Swiss Alps belongs to the most spectacular mountain landscapes in Europe.
The promising thunderstorm conditions in August 2015 were ideally suited to photographing this panorama from the summit of Eggishorn (2,869 meters, 9,413 feet). The active thunderstorm line was still about 6 kilometers (3.7 miles) away when these images were taken. The heavy rainfall of the approaching storm can be seen in the unstructured gray clouds on the left side of the image behind Bettmerhorn (2,857 meters, 9,373 feet). This seemed to leave enough time to complete the 57 individual exposures for this 220° panorama and begin the descent from the summit in time.
Yet even to a trained meteorological eye, the rapidly changing cloud cover concealed the formation of a new thunderstorm cell directly above Eggishorn. Working behind my sturdy metal tripod, I first noticed a tingling sensation rising from my feet toward my head, followed by the hairs on my body standing on end. What I felt was the electrical pre-discharge associated with the developing lightning channel. Instinctively, I threw myself to the ground, only to realize immediately that the metal tripod was now standing above me. At that very moment, there was a deafening bang as lightning struck, and the thunder rolled through the broad glacial valley before echoing back from the opposite mountain walls.
As I slowly rose, I noticed flames of St. Elmo’s fire sparkling from my fingertips. These rare and ghostly luminous phenomena, caused by electrical charges in the atmosphere, glow blue-violet because of the spectral emission lines of oxygen and nitrogen. Never before had I come so close to being struck by lightning. I could literally smell and taste the electrical charge in the air around me while adrenaline surged through my body. In feverish haste, I finished the remaining two exposures, threw the photographic equipment unsorted into my backpack, and rushed from the summit toward the valley as the next lightning bolts were already striking far too close. On the way down, the heavy rain finally poured over me. Gradually, however, the thunderstorm lost its intensity and drifted away.
With a length of 22 kilometers (13.7 miles) and a width of 1,500 meters (4,900 feet), the Aletsch Glacier is the largest and longest glacier in the European Alps. Its meltwater flows through the Massa Gorge into the Rhône. The glacier originates at Konkordiaplatz in the Jungfrau region at an elevation of 3,800 meters (12,467 feet). Its cold accumulation zone can be seen where the pale yellow light of the sun illuminates the glacier. This region receives more snow in winter than can melt during summer and is where the glacier gains mass.
The numerous dark bands that give the glacier its characteristic appearance are medial moraines. They form where the individual glaciers feeding the ice stream meet and merge. The rock debris carried along the margins of each glacier accumulates along these medial moraines. Where these bands first become visible upslope, the equilibrium line is located, where the average air temperature is around 0°C (32°F). Below this line lies the much larger and warmer ablation zone, where more ice melts than is supplied from the accumulation zone.
The view of this ice giant therefore reveals a glacier in severe mass-balance decline. At the end of summer, its medial moraines are visible even at the highest elevations. The darker the ice surface becomes, the more solar energy it absorbs, causing the surface to warm and the ice to melt faster. This self-reinforcing feedback accelerates ice loss as temperatures continue to rise.
Climate change is leaving its unmistakable imprint on the Aletsch Glacier. Its condition reflects the changing climate of our planet. During the height of the last ice ages, the Aletsch Glacier filled the entire valley. Wherever bare rock is exposed today, the valley was once covered by ice. Only the jagged and rugged peaks protruded above the vast ice system.
During the ice ages, the shape of the glacier was not determined by the relief of the ground beneath it. At the last maximum extent of the Alpine glaciers around 1850, the ice of the Aletsch Glacier was approximately 100 meters (330 feet) higher than today. This former ice level can still be recognized by the vegetation-free lateral moraines and rock faces that stand out brightly against the much darker rocky terrain above.
Since 1850, the glacier has retreated more than 3 kilometers (1.9 miles). At the terminus, it is currently losing about 10 meters (33 feet) of length per year. During hot summers, however, the loss can exceed 100 meters (330 feet). Its flow velocity varies between 50 and 180 meters (164 to 590 feet) per year, depending on the location of measurement. The ice thickness ranges from 900 meters (2,950 feet) at Konkordiaplatz to 150 meters (492 feet) at the terminus. Climate projections suggest that by the end of this century, the Aletsch Glacier will have disappeared as a continuous body of ice.
In the Moosfluh area toward the terminus of the Aletsch Glacier, the rapid retreat of the ice is destabilizing the surrounding mountain slopes. This slowly moving landslide could eventually trigger a massive rockfall. As the glacier retreats, it can no longer stabilize the mountain slopes as effectively. At the same time, permafrost is retreating from the bedrock. This allows rain and meltwater to penetrate deeper into the rock, further weakening it. Repeated freezing and thawing continues to rapidly erode the bedrock. Such freeze-thaw cycles now occur on more than half of the days throughout the year in the Aletsch Glacier region.
In the basin between Eggishorn and Strahlhorn lies the small lake Märjelensee. At the glacier’s maximum level in 1850, Märjelensee was dammed by the ice and formed a glacial lake that repeatedly and abruptly drained through channels opening within the glacier’s crevasses. These sudden outbursts generated torrential floods that cascaded through the Massa Gorge into the Rhône Valley. By contrast, the larger Vordersee is a more recently formed reservoir.
On the far right side of the image, the 4,274-meter (14,022-foot) Finsteraarhorn is illuminated by the pale yellow light of the thunderstorm. The 14.8-kilometer (9.2-mile) Fiescher Glacier originates in this mountain range. It is the second-longest glacier in the Alps after the Aletsch Glacier.
The feeling of experiencing this stormy atmosphere on the summit of Eggishorn, high above the Aletsch Glacier, was intoxicating. The dramatic light across the landscape and the visceral experience of almost being struck by lightning made the adventure behind this photograph unique and unforgettable.
