Volcano Monitoring Practical

Four volcanoes are involved in the practical and the student group should be split accordingly (with large classes it may be necessary to have different groups assessing the same volcano, although I generally give them different numbers so that it is not obvious that the volcanoes are the same). I have found that the optimum group size is 6-8 students.

The timing of events are all based upon real eruptions: volcano 1 is based on the Pinatubo eruption of 1991, volcano 2 on the Krakatau eruption of 1883, volcano 3 on the 1991-1993 eruption at Mount Etna (although in this practical it doesn't erupt) and volcano 4 is based upon a mixture of the Japanese volcano Unzen (1991 pyroclastic flow eruption) and Mount St Helens (1980). The hazard zonation maps for volcanoes 1 and 4 are identical.

The initial instructions for the four volcanoes should provide the students with enough information about volcanic alert levels. However, the students will need to have heard about COSPEC measurements, gravity measurements, harmonic tremors and gas emissions from volcanic flanks (although these are all at a fairly basic level in the practical).

It will be necessary for each group to designate one student member who will collect the activity reports. Subsequent reports will only be given on submission of the previous decisions and students should therefore keep a record of the date of the previous report, the alert level, evacuations etc. on the Summary Sheet. It is also important to make sure that the students cannot see how many activity reports are remaining, as this will effect their decision on when the final eruption will take place (it is tempting for the students to interpret some of the precursor activity as leading to an imminent eruption).

In order to maintain 'stress' levels it is useful to put pressure on slower groups - this often leads to hurried, rash decisions.

In the past I would follow the prediction part of the practical with a presentation by each group, in which the spokesperson outlines the information which was available for each volcano, the activity reports, the hazard zonation map (I generally provide these for the students on an overhead transparency) and the decisions the group chose and their reasons for the decisions. However, if the group size is too large for presentations to be practical it has been useful to combine two groups to discuss their actions with each other; this works particularly well if the groups have been working on the same volcano.

I have found that common 'errors' are for students to:

• evacuate too many villages too quickly (many groups happily evacuate all villages at the slightest sign of trouble. It is important for the students to appreciate the problems involved with evacuation);
• go to a high alert level too quickly
• try to lower the alert level too quickly
• allow people to return to villages when it appears that volcanic activity has decreased

I would be grateful for any comments and suggestions about how the practical could be improved.

Practical Files

• An introductory note for the students, plus information about the hazard alert levels used at Mount Pinatubo.
• Hazard zonation map for volcanoes 1, 3 & 4 and a very basic location map for volcano 2.
• Summary sheet.
• Daily activity reports. These should be cut into separate 'days' and given to the students when they submit the previous report. The students should keep a note of their decisions on the summary sheet. The practical works best if the students cannot see the number of activity reports remaining.

Phil Gravestock
GDN Project Officer

GEMRU
Francis Close Hall
Swindon Road
Cheltenham
Gloucestershire, UK
GL50 4AZ

Tel: 01242 543368
Fax: 01242 532997
Email: pgravestock@glos.ac.uk