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Table 1 Variables and values used in calculations

From: Using infrasound to constrain ash plume rise

Gas velocity modelling
Variable Definition Value/units Reference
u Eruption velocity (Calculated, see below)  
Π Acoustic power (Not calculated)  
ρ air Air density 1.4 kg m-3  
c Speed of sound 320 m s-1 McNutt et al. (2013)
τ Source duration 2 s  
K d Dipole source empirical constant 10-2 Woulff and McGetchin (1976)
R Volcanic vent radius 30 m Wessels et al. (2013)
r Source-receiver distance 12.2 km McNutt et al. (2013)
Plume modelling
  Parameter Value/units Reference
  Vent longitude and latitude 60.48°, –152.74°  
  Vent elevation 2400 m  
  Gas mass fraction 0.03 Mastin et al. (2013)
  Source temperature 1173 K Mastin et al. (2013)
  Solid pyroclastic density 1200 kg m-3 Mastin et al. (2013)
  No-wind train coefficient 0.09 Woodhouse et al. (2013)
  Wind entrainment coefficient 0.9 Woodhouse et al. (2013)
  Calculated peak eruption velocities Event 2: 315 m s-1  
   Event 17: 251 m s-1