(5)            The talus cone of le Jeur Noir (Muraz, VS)

The talus cone of Muraz is so perfect that it is not possible to miss it. Its slope angle is 35°, the ideal one (Fig. 1) and its conic form is demonstrated.

Active talus cones possess a frequent activity to avoid any human construction. They are natural hazard “naturally” managed. It is a typical hazard with high frequency but low energy (Figs. 2 and 3).

Fig. 1 : View of the conic talus slope.

Fig. 2 : (a) Talus slope presenting an ideal slope of 35° (Base map digitize and modified from Monthey 1284; Swisstopo).

Fig. 3: The 3D histogram of the topographic orientation indicates that topography is near a cone of slope 35° ( Projection of the lower hemisphere of Schmidt).