TephraFits

TephraFits is a Matlab function for describing the geometry of tephra fallout deposits. Using field data, it allows to:

• Fit contour maps using using exponential, power-law and Weibull methods (Fierstein and Nathenson 1992; Bonadonna and Houghton 2005; Bonadonna and Costa 2012);
• Calculate the deposit volume using isopach;
• Calculate the deposit mass using isomass;
• Estimate the decay of clast diameter using isopleth;
• Calculate transects as a distance from the vent;
• Classify eruptions using Pyle (1989) and Bonadonna and Costa (2013);
• Perform uncertainty assessment using Monte-Carlo simulations (Biass et al. 2014).

The associated paper has been accepted in Journal of Applied Volcanology.

Documentation

For a detail description of the usage of the function, navigate to the root of TephraFits in Matlab and type:

>> help tephraFits

Additionally, the file demo.m contains examples and additional updates are described at https://e5k.github.io.

Citation

TephraFits was published as a Methodology paper in Journal of Applied Volcanology available here and here. Please cite as:

Biass S, Bonadonna C, Houghton BF (2019) A step-by-step evaluation of empirical methods to quantify eruption source parameters from tephra-fall deposits. J Appl Volcanol 8:1–16

Biass S, Bonadonna C, Houghton BF (2019). TephraFits. doi:10.5281/zenodo.3590642

License

TephraFits is released under a GPL3 license, which means that everybody should feel free to contribute, comment, suggest and modify the code for as long as any new update remains open-source. A copy of the complete license comes with this function.

The GPL3 License covers tephraFits. The authors of dependencies used in this function retain the copyright to their works. In particular, I am grateful to:

• J. Landsey for the function bplot
• J. D'Errico for the function fminsearchbnd
• J. Wells for the function rsquare
• A. Horchler for the function waittext

Don't hesitate to contact me by email should you have a suggestion or find a bug.

Hope this code will help!

Copyright Seb Biass (sbiasse AT ntu DOT edu DOT sg) - 2018

References

• Biass, S., Bagheri, G., Aeberhard, W., Bonadonna, C., 2014. TError: towards a better quantification of the uncertainty propagated during the characterization of tephra deposits. Stat. Volcanol. 1, 1–27. doi:10.5038/2163-338X.1.2
• Bonadonna, C., Costa, A., 2012. Estimating the volume of tephra deposits: A new simple strategy. Geology 40, 415–418.
• Bonadonna, C., Houghton, B., 2005. Total grain-size distribution and volume of tephra-fall deposits. Bull Volcanol 67, 441–456.
• Bonadonna, C., Cioni, R., Pistolesi, M., Connor, C., Scollo, S., Pioli, L., Rosi, M., 2013. Determination of the largest clast sizes of tephra deposits for the characterization of explosive eruptions: a study of the IAVCEI commission on tephra hazard modelling. Bull. Volcanol. 75, 1–15. doi:10.1007/s00445-012-0680-3
• Fierstein, J., Nathenson, M., 1992. Another look at the calculation of fallout tephra volumes. Bull Volcanol 54, 156–167.
• Pyle, D., 1989. The thickness, volume and grainsize of tephra fall deposits. Bull Volcanol 51, 1–15.