When we think of Mont Blanc, we think of excellent climbing, amazing views and incredible snow-capped peaks, but little know about the dark history of Mont Blanc and the once-thriving towns it destroyed in 1892 after the Mont Blanc Massif released a hidden lake within the Tête Rousse Glacier upon the town of Saint-Gervais-les-Bains and the small hamlet of Bionnay.
The 1892 Mont Blanc Catastrophe
Late in the evening on 11 July 1892, the Tête Rousse Glacier released 200,000 cubic meters of water and ice from within a large pocket hidden within the glacier that had accumulated water over the years, forming what is now called an “englacial lake.”
The timing of the flood contributed the massive loss of life in the small hamlet of Bionnay and the surrounding area – the townspeople were asleep and unable to escape; they had no chance at survival. The bathhouse of Saint Gervais was flooded, but, the most of the damage was done to the town of Bionnay, which was completely destroyed. The damaged reached as far as Le Fayet, and where water flowed, all that was left behind was 800,000 cubic meters of sediment. Among the only records found in Bionnay were school attendance sheets that marked the town’s children’s last day of attendance.
At the time of the event, one of the only safe people was Joseph Vallot, a glaciologist and the Director of the Mont Blanc Observatory in 1892. He noted in his accounts that after visiting the glacier, it was evident that part of the glacier’s terminus, or snout, had been torn away, revealing a 40-meter-long cavity where the displaced water was once contained. His estimations noted that 100,000 cubic meters of water, 100,000 cubic meters of ice, displaced rock and soil and the force of rushing water produced a weight of 500 kilograms that all fell upon the lower-lying towns. He warned that this would happen again in the future and advocated for explosives to be used to permanently route any accumulation of water away from the villages.
The Threat of Future Englacial Lake Floods
Englacial lakes are known to be very rare but dangerous natural occurrences, with only a few recent studies conducted on their anatomy, like the one featured in Discovery Channel’s Mont Blanc Mega Flood Disaster special. Because of this, where one is located and whether or not one of its walls will fail and produce a catastrophic flood is completely unpredictable.
In 1904, the predictions of Joseph Vallot were proved when a second pocket was discovered within the glacier. Authorities drilled a hole into it to release 22 cubic meters of water. Since then, concern has grown around the site, with a few scientific explorations having been conducted to better understand how englacial lakes are formed, identify them and possibly prevent future catastrophes; but the threat still remains even with the recent advancements in discovery. In 2010, the Daily Mail published an article detailing the growing concern of another glacial flood after a subglacial lake pocket was found under Mont Blanc. Up to 65 cubic meters of water was found in the reservoir, and hikers near Saint-Gervais were diverted away from the area. This pocket was approached differently, with engineers drilling holes into the top of the glacier and pumping out the retained water. The pocket was discovered by researchers of the French National Center for Scientific Research (CNRS).
Saint-Gervais and Bionnay
Once, and still, a luxury bath house town, Saint-Gervais-les-Bains played host to the rich and famous visiting France. It was a quiet town filled with the air of relaxation. For two hundred years, Saint-Gervais has maintained luxurious thermal spas that, for their hydrotherapeutic waters, became known as rejuvenating centers for health. Today, the town serves as a gateway to the Chamonix Valley and a staging post for climbing Mont Blanc. The town still boasts the beautiful 19th-century architecture and provides beauty treatments and thermal spas for its visitors.
Bionnay is a small hamlet just outside of Sain-Gervais and was a quiet countryside town filled with a relaxed population. The hamlet was home to the everyday school children, women and men who lived and worked a simple life. In 1892, Bionnay was completely swept away and almost all of its residents killed by the englacial flood. Today, Bionnay is home to private luxury Chalets that house adventurous ski tourists and still boasts its beautiful and countryside ambiance.
Blaizot, Denis. “La Catastrophe De Saint-Gervais (12-13 Juillet 1892).” La Catastrophe De Saint-Gervais. Gloubik Sciences, 30 July 2010. Web. 28 Jan. 2017. <http://sciences.gloubik.info/spip.php?article1017>.
Unknown, Author. “St Gervais, the History, the Life & the Property Market.” Alpine Blog RSS. France Property Angels, 24 May 2014. Web. 28 Jan. 2017. <http://francepropertyangels.com/alpine-property-blog/filter-categories/property/st-gervais-the-history-the-life-the-property-market/>.
Clark, Tim “Flood risk in French Alps after water pocket discovered under Mont Blanc glacier.” Daily Mail Online, 4 Aug. 2010. Web. 28 Jan 2017. http://www.dailymail.co.uk/travel/article-1300220/Flood-risk-Mont-Blanc-water-pocket-discovered-glacier.html
Contributors, Multiple. “Tête Rousse Glacier.” Wikipedia. Wikimedia Foundation, 22 Aug. 2010. Web. 28 Jan. 2017. <https://en.wikipedia.org/wiki/T%C3%AAte_Rousse_Glacier>.