Tephra2 Inversion Tool

Tephra2-inversion can use field measurements of tephra (location: easting and northing, accumulation: mass (kg/m^2) or thickness) to estimate a set of possible eruption parameters that could be used by the forward modeling tool to recreate an eruption deposit that closely matches the field data supplied. The inversion is particularly sensitive to the wind field. The inversion tool tests NOAA REANALYSIS wind models, from one year, to find the wind field that best recreates the tephra deposit sampled.

Tephra2-inversion - At a Glance

Inputs

Tephra2-inversion inputs:

  • Volcanic vent location. Choose the volcano from pull down menu.
  • Eruption mass. Specify a range for the total mass of pyroclastic ejecta (kg)
  • Plume height (m); specify a range (minimum and maximum).
  • Set alpha and beta, parameters in a Beta distribution which control the eruption column shape, which is strongly dependent on initial volatile content.
  • Set the total particle size distribution of the pyroclastic ejecta, assuming a lognormal distribution. Set minimum, maximum, mean (median) and standard deviation.
  • Set particle diffusion constants to account for particle-particle interaction and turbulence (both in the eruption plume and in the atmsophere for analogous eruptions).
  • Set particle densities.
  • Wind velocity varies as a function of height. Wind velocity is constant within a given stratum. Wind velocities as a function of height are sampled from the NOAA REANALYSIS database for the volcano

Outputs

Tephra2-inversion outputs:

  • You can download the various files created during the inversion process

Tephra2-inversion is under construction ยป

References

Connor, Laura J., and Charles B. Connor (2006) Inversion is the key to dispersion: understanding eruption dynamics by inverting tephra fallout In H. M. Mader, S. G. Coles, C. B. Connor & L. J. Connor (Eds.), Statistics in Volcanology, Geological Society of London Special Publications 231. DOI 10.1144/IAVCEI001.18