He focused on studying “small glaciers”, those located in the bottoms of glacial valleys in the Alps and which are “almost unknown to everyone”. Frédéric Mathieu has just launched a brand new magazine, Glacial relics, dedicated to the exploration of these “terminal” glaciers. Because most are indeed “threatened with imminent disappearance”. Interview.
What findings did you make during your research?
I study around fifty glaciers. I was interested in their evolution since the end of the Little Ice Age, that is to say from the 1860s. To do this, I worked on general maps dating from those years, then aerial shots from the 1930s until today.
The observation is that their condition is truly catastrophic, we are observing a spectacular decline. They are terminally ill. Either they have completely disappeared, or, if they were substantial and they rose a little high, they have receded several kilometers. These are glaciers of which almost nothing remains in appearance. They were a beautiful glacial feature with crevasses. Now, we only see scree in the landscape. Moreover, the IGN puts “former glaciers” on its maps. However, from the moment a glacier is covered with scree, its lifespan increases.
That’s to say ?
Beneath these scree remains buried ice, called “relic ice”, which will diffuse water throughout the biosphere for decades, depending on the volume. My challenge was to go into the field to explore these glaciers that we knew about a century ago and see if there was any buried ice left.
Should we see this as a sign of hope?
Compared to the 1860s, 80% of the ice has melted. The rest, that is to say not much, is buried under this scree. This means that the glacier is no longer regenerating, even if it can still release some water.
What are the prospects for future years? Are they as alarmist as the findings?
They are alarmist because the decline observed has not been uniform. Initially, it operated quietly, but from the end of the 20th century, we witnessed an acceleration with pronounced jolts during major heatwaves, such as those of 2003, 2019 and 2022. They really damaged what little remained of the glaciers.
The observation is clear: if we do not really reduce greenhouse gases, these glaciers will disappear. Those covered in scree will resist a little better. For others, life expectancy is less than ten years. However, a valley that no longer has ice means a whole part of the biosphere disappears.
How many do you estimate the number of small glaciers doomed to disappear in the Alps?
It’s difficult to answer precisely, but it’s around a hundred, maybe two hundred. Take the example of the Archeboc glacier. When I saw it, his glacial relic measured about two meters wide by two meters high. It is very likely that she has since disappeared. Whether large, like the Mer de Glace, or small, each glacier has its importance. That of Tabor still contains several hundred million cubic meters of fossil ice. This means that it will still be able to diffuse water for several decades. The problem is that we will really notice the change the day there is no more water and the animal or plant species in the area disappear.