In this incredible footage, a French paraglider named Rémi Bourdelle while flying above Couloir du Gypaète in the French Alps.
In the insane clip, a boulder gets catapulted and leaves a huge trail of rocks and dust in its path.
The rockfall sends tons of debris down the slopes, and Bourdelle gets to have a front row seat from a literal sky-box. The paraglider records the footage from his headset camera. As he looks around at the rockfall below, it’s clear how quickly the avalanche advances and how it picks up steam as it rolls down the mountain.
You can watch the entire viral clip below.
“While flying in the garden, I see a little rock fall above the Gypaète couloir, nothing scary for the time being but a few seconds later, it’s a huge mountains section that has collapse,” Bourdelle wrote of the footage. “The sound is loud, the stones bounce everywhere and the tress are like bowling pins… The biggest stones end their crazy run near the paravalanche at the forest edge. Something to think about when you fly very close to the cliff.”
The French Alps are the portions of the Alps mountain range that stand within France. They are located in the Auvergne-Rhône-Alpes and Provence-Alpes-Côte d’Azur regions.
At 15,774 ft, Mont Blanc, on the France–Italy border, is the highest mountain in the Alps and also the highest Western European mountain.
Rockfalls Caused Primarily by Geological and Weathering Conditions
A rockfall is considered a group of rocks free-fall from a cliff. The term can also be used for the collapse of rock from roof or walls of mine or quarry workings.
A rockfall occurs when a fragment of rock becomes detached by sliding, toppling, or falling. The rock then falls along a vertical or sub-vertical cliff, and continues to proceed down the slope. It bounces and sprays other rock trajectories along its path.
Moreover, a rockfall could also be considered “the natural downward motion of a detached block or series of blocks with a small volume involving free falling, bouncing, rolling, and sliding.”
Geology and climate make up the main causes of rockfall. Factors include condition of the rock mass, discontinuities within the rock mass, susceptibility to weather, and ground and surface water. Additionally, freeze-thaw, root-wedging, and external stresses cause rockfalls.
For instance, a tree could be blown by the wind and cause stress on its roots. This could in turn loosen rocks and trigger a fall. Then, pieces of rock collect at the bottom, and rocks then fall from the cliff and can dislodge other rocks. It basically creates an avalanche effect.
Normally, rockfall events can be prevented in one of two ways: either by passive mitigation or active mitigation. Passive mitigation is where only the effects of the rockfall event are mitigated and are generally employed in the deposition or run-out zones.
Active measures include rock bolting, slope retention systems, shotcrete, etc.