Block SPECIES_TGSD

These blocks define the TGSD for each species and are used by the SetTgsd task to generate some basic distributions

1. NUMBER_OF_BINS = (integer)
   • Number of bins in the TGSD
   • Note: This value can be different from the number of classes defined in the granulometry file *.grn created by the SetSrc task if aggregate bins are included later on or if a cut-off diameter is imposed
2. FI_RANGE = (float_list)
   • A list of two values defining the minimum and maximum diameters in phi units
3. DENSITY_RANGE = (float_list)
   • A list of two values defining the minimum and maximum densities
   • Note: Linear interpolation (in phi) is assumed between the extremes
4. SPHERICITY_RANGE = (float_list)
   • A list of two values defining the minimum and maximum values for sphericity
   • Note: Linear interpolation (in phi) is assumed between the extremes
5. DISTRIBUTION = (options)
   • Type of TGSD distribution
   • Input options:
     • GAUSSIAN: Gaussian distribution
     • BIGAUSSIAN: bi-Gaussian distribution
     • WEIBULL: Weibull distribution
     • BIWEIBULL: bi-Weibull distribution
     • CUSTOM: Custom distribution from an external user file
     • ESTIMATE: TGSD is estimated from column height and magma viscosity (for tephra species only)

Sub-block IF_GAUSSIAN

Used when DISTRIBUTION=GAUSSIAN

1. FI_MEAN = (float)
   • Mean of the gaussian distribution in phi units
2. FI_DISP = (float)
   • Standard deviation of the gaussian distribution in phi units

Sub-block IF_BIGAUSSIAN

Used when DISTRIBUTION=BIGAUSSIAN

1. FI_MEAN = (float_list)
   • A list of two values in phi units defining the means of two gaussian distributions
2. FI_DISP = (float_list)
   • A list of two values in phi units defining the standard deviations of two gaussian distributions
3. MIXING_FACTOR = (float)
   • The mixing factor between both gaussian distributions

Sub-block IF_WEIBULL

Used when DISTRIBUTION=WEIBULL

1. FI_SCALE = (float)
   • Parameter of the Weibull distribution
2. W_SHAPE = (float)
   • Parameter of the Weibull distribution

Sub-block IF_BIWEIBULL

Used when DISTRIBUTION=BIWEIBULL

1. FI_SCALE = (float_list)
   • List of parameters for the bi-Weibull distribution
2. W_SHAPE = (float_list)
   • List of parameters for the bi-Weibull distribution
3. MIXING_FACTOR = (float)
   • Parameter of the bi-Weibull distribution

Sub-block IF_CUSTOM

Used when DISTRIBUTION=CUSTOM

1. FILE = (string)
   • Path to the file with the custom TGSD

Sub-block IF_ESTIMATE

Used when DISTRIBUTION=ESTIMATE

1. VISCOSITY_(PAS) = (float)
   • Magma viscosity in Pa.s
2. HEIGHT_ABOVE_VENT_(M) = (float)
   • Eruption column height above vent in meters