Discharge rate of explosive volcanic eruption controls runout distance of pyroclastic density currents

We address, through quantitative analysis of results from independent studies, the control discharge rate explosive volcanic eruptions on runout distance highly hazardous pyroclastic density currents. analyze with statistical methods data 47 well-documented currents runouts ?3–185 km and generated by minor to super-eruptions rates Q?107–1012 kg/s. Our shows first that during phase is average 13.6 times greater than preceding plinian phase. further find both dilute turbulent two-layer flows a concentrated base correlates remarkably well rate. By applying power law relationships we infer, next model as yet unknown over 53 events, including 27 super-eruptions. At given rate, travel land generally farther their counterparts, they are even more mobile when propagating water. demonstrate current scales (Q/w)0.5, w particle settling velocity, in agreement theory. Assuming PDCs obey same principle infer velocities ?1–10 m/s for these show also classical deposit aspect ratio, AR, allows discriminate between emplacement (AR?5×10?5) current, which permits us discuss dynamics produced Ito (29 ka) Taupo (AD 232) eruptions.