There he arrived, a seething deluge of rubble, with “chunks of ice the size of cars,” as British tourist Harry Shimmin wrote on Instagram. “Yes, I let it arrive at the last second before I started moving. And yes, I know it would have been safer if I had taken shelter right away. I took a huge risk,” Shimmin admits afterwards.
But the moment the ice avalanche thundered at him this week, high in the mountains of Kyrgyzstan, he was transfixed. Shimmin was on a nature walk with eight Britons, an American and a mountain guide when it happened. A breaking glacier point, high above him. Just when he was filming, some distance from the group. “Five minutes into our journey and we would all have been dead,” writes Shimmin. Now two of the tourists were slightly injured by tripping. Shimmin himself escaped unscathed.
Another ice avalanche. The last bodies of the 11 victims who fell when an ice mass broke off the glacier on the Marmolada, in the Italian Alps, were recovered this week in the Italian Alps. And in India last year, 204 people died when millions of tons of ice and rock fell from no less than 3.5 kilometers high on a power plant.
The climate is behind it, said Italian Prime Minister Mario Draghi, immediately after the disaster in Italy. Because more heat, more melt. ‘This summer could be the perfect storm for glacial disaster’, warned the Milanese glaciologist Giovanni Baccolo, referring to the heat and light snowfall, which could further insulate the glaciers. “Glaciers like the ones on Marmolada are climatic fossils, they should be receding.”
Or are appearances deceiving and is it simply because more and more people are walking around in the mountains, with the camera always at the ready? An unraveling, in three observations.
1. Glacier avalanches are of all times
‘Someone came walking into the village of Kandersteg, sweaty and exhausted, shouting: The Altels has fallen! Everything is dead, people and cattle, everything! (…) Some parts of the body were seen here and there; they dug and found the more or less mutilated corpses. They were surprised in their sleep, almost completely naked; Councilor Rothen was hurled 150 yards away.’
That’s how it went, according to a report in the Haagsche Courant from that time, on September 11, 1895, in the Swiss Alps. During the ice avalanche that morning, 4 million cubic meters of ice came down, with a deafening noise. Pastures at the bottom of the mountain were buried, everywhere were ‘ice balls that glittered like white marble’, six people and 170 cows were killed.
Think of glaciers and most people think: that’s that slow thing that creeps down very gradually and then slowly withers away from melting. But fractures followed by a devastating ice avalanche, usually on a steep slope such as in Kyrgyzstan or on the Marmolada, are also sometimes present. Peering at satellite photos of the broken glacier in Kyrgyzstan, glacier researcher Bas Altena (Utrecht University) detects dark spots, which indicate ‘a lot of dynamism’ in the area. ‘So a lot of rock avalanches. And now also a documentation of an ice avalanche.’
There are several types of ice avalanches, Swiss and French glaciologists led by Jérome Faillettaz of the University of Zurich write in a review article published last year. If the glacier is frozen solid on a cold, dry surface, a slab of ice can tear off the top – judging by the photos, as happened on the Marmolada. Or the bottom is warm enough: then the glacier can be ‘lubricated’ from below by melt water and a part can tear loose and shoot away, like a melting ice cream that slides off its wooden stick.
Things can also go wrong on gently sloping slopes, if the bottom of the glacier melts into a muddy sludge over which you would slip as an ordinary person, documented the Norwegian Andreas Kääb together with international colleagues. A relatively newly discovered phenomenon, brought to light on September 20, 2002, when a massive mass of ice and debris ripped off the Kolka Glacier in the Russian Caucasus. More than 120 people were killed, including a 27-person film crew, whose ranks were idol Sergei Bodrov Jr., a sort of Leonardo di Caprio of Russia.
The estimated speed of that flat ice avalanche was no less than 300 kilometers per hour. It’s that speed, combined with the mass, that makes ice tsunamis so deadly, Altena says. ‘Falling ice has more impact than a dry rock avalanche, because the ice can change phase during the discharge, which acts as a lubricant.’
2. The hand of the climate is present, but often difficult to identify
It can’t be a coincidence, experts think. The glacial disaster on the Marmolada occurred after days of mild weather. The glacier may be at 3,300 meters altitude, on the highest peak of the Dolomites, prior to the rupture it was 10 degrees, according to a reconstruction in the French newspaper Le Monde. Ideal for leading to expanding meltwater in crevices in the glacier, which would have gradually pushed the now broken off piece loose.
“There is almost always some kind of weather factor involved. For example, warm weather or rain causes meltwater to reach the bottom of the glacier, making it easier to slide,’ says Walter Immerzeel, professor of mountain hydrology at Utrecht University. It is therefore entirely conceivable that the warming climate will lead to more glaciers breaking down: more heat and rain is what you get.
Take the collapse of two adjacent glaciers in Tibet in July and September 2016. Some shepherds were killed, in the West the disaster did not even make the news. But in the stately scientific magazine Nature Geoscience disaster did appear. Since scientists have been tracking the glaciers since 1961, Andrew Kääb .’s team was able to reconstruct in detail what had happened.
The climate clearly had a hand in it. In the decades leading up to the disaster, the glacier had gradually retreated higher up. Meanwhile, there was more snowfall, making the glacier on top heavier. The result was a hydrocephalus glacier: a mass of bubs on top, while the foot that gave it stability melted away.
And then it started to rain again. About 20 centimeters fell the summer before the disaster. From satellite photos, Kääb’s group saw mudflows forming at the bottom of the glacier several days before the collapse. Although the slope on which the top-heavy glacier rested only sloped about 5 to 7 degrees, that lubricated the thing enough for an icy slide. On July 17, 2016, at a quarter past eleven in the morning, glacier number one went down; two months later, glacier number two followed, just a few miles away.
But no ice disaster is the same. Other times, the hand of the climate is more difficult or even impossible to identify, notes an American-European research team, which last year traced what exactly went wrong with the glacial disaster with the 204 deadlast February in India.
Yes, ‘the stability of glacier-capped and perpetually frozen mountain sides is particularly sensitive to climate change,’ the team writes in science. But in this case, the glacier was a kilometer above the frost line, and the disaster may have simply been caused by chemical crushing of the rock soil. What aggravated the disaster was the eerie height from which the glacier clambered down. The friction melted the ice and created a raging, churning river of ice full of debris and rock, flattening everything in its path.
3. Warning helps (and sometimes bending too)
And if such a mass of ice of tens of millions of cubic meters then comes at you at 300 kilometers per hour – what then? Fences and nets to stop snow avalanches will probably only help to a limited extent. After the Swiss glacial disaster of 1895, witnesses saw how the ice had completely crushed a forest. The trees were ‘all uprooted and lay side by side as regularly as if they had been laid there by human hands’.
Better keep an eye on the glaciers then? Must be possible, Vincent suggests. Bursting glaciers can give off specific seismic signals—ice quakes—that can tell you if meltwater is pushing the glacier apart somewhere inside. Take the Swiss Weisshorn Glacier, an overhanging slab of ice that has broken off five times since 1973. In the month before the last breach, in 2005, Swiss Jérome Faillettaz observed 1,731 icequakes, most of which were heard as a deep, growling sound. Get out.
Water or cracks can also be a giveaway: think of the slippery mud streams that started flowing under the twin glaciers in Tibet. Prior to the Marmolada disaster, a striking crevasse with a small lake on top was seen: not exactly a favorable sign either. ‘You will have to look at it per region and per type of glacier,’ Immerzeel thinks. ‘I think that at some point we will be able to roughly estimate what kind of risks there are. But a prediction in the sense of: the Marmolada will break down on 4 July, that’s impossible.’
For Harry Shimmin, the Brit who saw the ice avalanche in Kyrgyzstan approaching, the solution was simple: one step to the side, and duck, behind a solid rock. On his video you can just see how the avalanche, literally, flies over him. “It got dark and harder to breathe. For a moment I thought I was going to die. Only when it was over did the adrenaline kick in.’