A step-by-step evaluation of empirical methods to quantify eruption source parameters from tephra-fall deposits

Table 3 Output variables of each fit type. nbSegments is the number of exponential segments

	Variable	Description	Size
Global
	X, Y	X and Y values of the fit used for plotting	n×100
	Ym	Computed Y values at observed X locations	n× number of X values
Deposit-specific
Isomass	mass_kg	Mass (kg)	1×n
	magnitude	Magnitude (Pyle 2000)	1×n
Isopach	volume_km3	Volume (km³)	1×n
	VEI	Volcanic explosivity index (Newhall and Self 1982; Houghton et al. 2013)	1×n
Fit-specific
Exponential	T0	Ordinate of the exponential segments	nbSegments×n
	k	Slope of the exponential segments	nbSegments×n
	I	Sqrt(Area) of intersection of the exponential segments	nbSegments×n
	b	Distance at which the y value halves. See text for details	nbSegments×n
	r2	R² value of the exponential fits	nbSegments×n
Power–law	m	Power–law coefficient	1×n
	TPL	Power–law exponent	1×n
	r2	R² value of the power–law fit	1×n
Weibull	theta	θ parameter of the Weibull fit	1×n
	lambda	λ parameter of the Weibull fit (km)	1×n
	n	n parameter of the Weibull fit	1×n
	r2	R² of the Weibull fit	1×n
	H	When dataType is isopleth, plume height (km asl) calculated with equation 7 of Bonadonna and Costa (2013)	1×n
Other
	range	Range of volume (km³; isopach) or mass (kg; isomass) corresponding to the interval of percentiles specified by errorBound (Table 1)	1×2

If the probabilistic mode is disabled, n=1. If the probabilistic mode is activated, TephraFits also outputs a second set of variables containing the outputs of all single Monte Carlo simulations, in which case variable names are appended by a P (e.g. VEIP) and n is the number of runs (nbRuns; Table 1)

ISSN: 2191-5040