Research
Articles
Goûter vs Trois Monts: an honest comparison of the two normal routes
The Gouter route is PD with a rockfall funnel that killed 102 people between 1990 and 2017. The Trois Monts is AD- with serac zones that shed ~60,000 m³ of ice in a single 2025 collapse — and it is the standard diversion when the Gouter is out of condition. Neither is the safe one. This is the side-by-side: grades, huts, hazards, escape options, and why guides cancel rather than upgrade.
The Grand Couloir: what the seismic sensors say — and why the 2026 accident broke the rulebook
Seismic sensors in the Grand Couloir du Gouter recorded one rockfall every 24 minutes during critical hours, with peak activity 18:00-20:00 and a statistically safest window at 09:00-10:00. Guides cross pre-dawn anyway — and both rules rest on the same assumption: that the night refreezes the mountain. On 18 July 2026, a UIAGM guide and his client were killed crossing at 02:30 in a heatwave. This is what the data says, why the old rule failed, and the rule that actually holds.
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