IAVCEI Commission on Tephra Hazard Modelling

OBJECTIVES

This IAVCEI commission was specifically born to deal with tephra hazard issues. We feel that it is extremely important to gather together scientists with different tephra hazard experiences (e.g. modelers, model users, field volcanologists) in order to integrate and improve current hazard approaches and tephra-dispersal models.

Therefore the commission is open to anyone interested in tephra hazard and anyone interested in contributing might join the group at any time (simply email us!).

Our primary goals are:

(i) Calibrating existing tephra-dispersal models;

(ii) Identifying potential improvements to existing models that would increase precision and accuracy;

(iii) Compiling a comprehensive dataset for modeling validation;

(iv) Defining a tephra-sampling protocol in order to standardize tephra collection and quantify the accuracy of eruptive parameters derived from field data;

(v) Determining feasibility of running specific models on different types of computer systems, such as individual personal computers, parallelized clusters, or remote servers using an internationally accessible Web-based interface;

(vi) Presenting the results in a framework that allows new research to be incorporated into analytical and numerical models for tephra hazard assessments.

To achieve these goals, we propose the following plan to be carried out in a series of meetings:

1) Exchange relevant published and unpublished information about modeling approaches and data used for model parameters.

2) Assemble data from a range of well-documented tephra-fall deposits for use in model testing.

3) Develop a shared, on-line database of open-source codes and data to facilitate rapid development and use of dispersion models.

4) Test model accuracies and associated uncertainties in calculating observed tephra-fall characteristics using measured eruption data as input parameters.

5) Improve existing models by integrating test results.

6) Obtain extramural funding to develop the tested models into a useable hazard analysis tool that can be widely distributed.

Our first meeting took place during the Cities on Volcanoes 3 conference in Hilo (Hawaii, July 2003). During this meeting we discussed goals #1 and #2, and how to proceed for goal #3 and #4. Our second meeting took place during the IAVCEI 2004 conference and was focused on the discussion of goals #5 and #6. Our third meeting was run as a 3-day pre-conference workshop associated with Cities on Volcanoes 4 in Quito (Ecuador, January 2006). During this last meeting we started working on the determination of crucial field parameters for the study of tephra deposits and their implications for tephra modeling. In particular, we focused on the determination of the “maximum clast”. Results of this meeting where presented and discussed during IAVCEI 2008 in Iceland (forth meeting).