Example of torrential lava, occurring in July 2003, in the Valgaudemar valley (Hautes-Alpes).

The debris-flow transported a lot of wood, typical for the first event after winter.

When the moraine dike retaining the lake broke, a torrential flood of lava brutally buried our mammoth.

In summer 2016, a debris-flow transporting huge boulders destroyed the measuring system installed in the Illgraben gully near Leuk (canton of Valais).

The largest recorded debris-flow in recent times occurred in 1961 and had a volume of several hundred thousand cubic meters.

However scientists warn the volcano could release another massive debris flow over populated areas any time without warning.

However scientists warn the volcano could release another massive debris flow over populated areas anytime without warning.

Two earlier debris flows, around 4,450 and 7,300 years ago, sent rubble at least 32 kilometers from the volcano.

Two previous debris flows, about 4,450 and 7,300 years ago, sent debris at least 32 kilometers from the volcano.

Two previous debris flows, about 4,450 and 7,300 years ago, sent debris at least 32 km (20 mi) from the volcano.

The largest recorded debris-flow in recent times occurred in 1961 and had a volume of several hundred thousand cubic meters.

You can also observe the remnants of the flow of debris and pyroclastic flow from the 1990 eruption of Mount Fugendake, which will really bring home the perils of nature.

And this is what the new system measured: it detected the debris-flow on June 10, 2019 at 8:40 p.m. about 140 m upstream of the measuring system.

In addition, radar and laser devices, acceleration sensors on the force plate and video cameras provide data about the volume, water content, density and velocity of the debris-flow.