Tephra2 Forward Modeling Tool

Input Parameters

First Step

Set the Basic Eruption Parameters

Eruption Mass (units = kg)

small volume large volume

Plume Height (units = m)

short plume tall plume

Define a Beta Distribution for Release of Particles from the Plume

Alpha parameter

0 10

Beta parameter

0 10

Define the Grain-size Distribution for the Eruption

Maximum Grain-size
(units = phi)

         51 mm
Coarse lapilli

 1 mm
Coarse ash

Minimum Grain-size
(units = phi)

      1 mm
Coarse ash

0.001 mm
Fine-ash

Mean Grain-size
(units = phi)

  -4.0
coarse

5.0
fine

Standard Deviation (Sigma)
(units = phi)

small
sigma

large
sigma

2.0

Define Diffusion Parmeters within the Eruption Column

Diffusion Coefficient
for coarse particles (units = m² s^-1)

low (0)
plume
spread

(1e9) high
plume
spread

Eddy Diffusion
for fine particles (units = m² s^-1)

low (0)
atmosphere
turbulence

(1) high
atmosphere
turbulence

0.04

Fall Time Threshold
for change in diffusion (units = sec)

     0
short
fall-time

1e9
long
fall-time

Specify a Density Model for Pyroclasts

Density for Lithic particles (units = kg m^-3)

Density for Pumice particles (units = kg m^-3)

Specify Number of Integration Steps

Column integration steps

      50
shorter
runtime

200
longer
runtime

Particle integration steps

     50
shorter
runtime

100
longer
runtime

Wind Field above the Volcano

Select an option

Wind File from NOAA Reanalysis II
(1 year of wind data, sampled 4 times daily)

January

December

Wind field above the vent
(3 columns separated by a space)

Example:
4000 20 90 (m m s^-1 deg-from-N)

Please be patient. Code execution may take up to 10 minutes depending on the scale of your submission. You will be notified when your run has completed.