Shear cell measurements of the internal and basal friction angles of pyroclastic material: implications for flowability of pyroclastic density currents

Dataset for measurements of internal and bed friction angles of pyroclastic material. Dataset includes the measurements of the normal stress, σ, and the shear stress, τ for fine and coarse pyroclastic material. The internal friction angles were measured for pre-shear normal stress, σp = 9, 7.5, 6, 4.5, 3, and 1.5 kPa. The bed friction angles were measured for pre-shear normal stress, σp = 9, 6, and 3 kPa for sandpaper of grit 40, 60, 120, 240, 320, and 400.