The Planpincieux glacier could collapse
With an elevation ranging from 3,660 m to 2,345 m (12,007 ft to 7,693 ft), this glacier is located on the Italian side of the Mont-Blanc massif, on the southern side of the Grandes Jorasses peak.
This summer, the glacier was moving with a speed of 50-60 cm (16-23in) / day. A record speed, as before 2019, the Planpincieux glacier had moved at a rate only occasionally exceeding 30 cm (11.8in) / day during summer months (The Independent).
This kind of fast movements within the glacier leads to the formation of crevasses, according to the Alaska Satellite Facility.
Dr Daniele Giordan is a geologist who works for the Italian National Research Council and is part of the team that has been monitoring the glacier since 2013.
“This year, we noticed again the presence of a large crevasse,” he said. “The opening of this crevasse can create the collapse of a very large block.”
Fractures in the glacier after summer months is normal, continues Dr Giordan, but the crack detected this time was extremely wide.
Dr Giordan declared for The New York Times that a block of 250,000 cubic metres or 8.8 million cubic feet (around 2.16 times the size of the Royal Albert Hall or 6.75 times the size of the United States Capitol Building) has splintered and could collapse.
The alarm was raised by the Valle d'Aosta regional government and the Fondazione Montagna Sicura (Safe Mountain Foundation) on Wednesday, 24 September 2019.
Monitoring of the Planpincieux Glacier, photo source @www.irpi.cnr.it
How does global warming affect glaciers?
Caused mostly by the burning of fossil fuels and the resulting buildup of greenhouse gases in the atmosphere, global warming is the most pressing issue of our times.
Global warming is exacerbating yearly. According to NASA’s Goddard Institute for Space Studies (GISS), the average global temperature on Earth has increased by about 0.8° Celsius (1.4° Fahrenheit) since 1880. Two-thirds of the warming has occurred since 1975.
The climate change is even more drastic in the Alpes, as the mountains have warmed by 1.5 degrees Celcius in the last century (wwf.panda.org).
And the rising temperature is highly affecting glaciers from all over the world.
Scientists from the National Snow & Ice Data Center argue that since the beginning of the twentieth century, glaciers from all over the world have been retreating at unprecedented rates. Some of them have disappeared already and many more may vanish within a matter of decades. For example, more than 85 per cent of the snows of Kilimanjaro had retreated in the past 100 years and they are believed to disappear within two decades (The Telegraph).
But rising temperature is not the only major factor leading to the retreat of the glaciers. The decrease in winter precipitation (snow) also has negative impacts on the glaciers (ScienceDaily).
Indeed, glaciers advance when snow is added to the upper region of the glacier. Provided that there is a subfreezing temperature, the water will go down the glacier, it will eventually melt and increase its mass.
In the absence of precipitation, glaciers do not advance. Moreover, rising temperatures cause the glaciers to melt from their lower region, causing fractures and the possibility of the frozen upper region of the glacier to collapse.
Being a temperate glacier, the Planpincieux is even more affected by global warming. As opposed to a polar glacier, a temperate one is at the melting point, meaning that liquid water coexists with the ice (USGS.gov).
Due to their consistency, temperate glaciers are heavily affected by even small changes in temperature.
Near the Planpincieux glacier' s peak front, there is a morphological step that determines a strong propensity to the activation of frequent ice falls in particular during the summer.
Experts fear that a large portion of the upper part of the glacier could detach and create a serac fall which will menace the Planpincieux hamlet (Instituto di Ricerca per la Protezione Idrogeologica).
It is impossible to predict when the glacier will collapse
As a precautionary measure, Stefano Miserocchi, the mayor of Courmayeur, decided to close roads in the Val Ferret on the Italian side of Mont-Blanc massif and to evacuate mountain huts in the Rochefort area.
He said there was no threat to residential areas and tourist facilities.
As we move toward winter and temperatures will drop and more precipitation is expected, it might be that the glacier will be steadier, so no one can say when or if the glacier collapses.
"These phenomena once again show how the mountain is going through a period of major change due to climate factors and, therefore, it is particularly vulnerable," Mayor Miserocchi told Italian media.
Mont-Blanc seen from the Val Ferret, photo source @https://commons.wikimedia.org/, licensed under CC BY-SA 4.0
Many collapses this summer
Global warming is heavily impacting the Mont-Blanc massif as many collapses took place this summer and the Mer de Glace has been severely shrinking throughout the years.
Young people and adults from all over the world are becoming more aware of climate change. On 20 September 2019, the Global Climate Strike took place all over the world and Chamonix joined it.
Moreover, scientists argue that the rising temperatures might prompt the actual physical disintegration of the mountains, as it is the case with the Matterhorn, one of Europe's tallest peaks.
Two people died on July 29th, 2019, when a rock pillar broke away in the Matterhorn mountain, in the Swiss Alps. Photo by Chil, licensed under CC BY-SA 3.0, photo source @wikimedia.org