Soufriere Hills Eruption, July 2008

Activation of International Charter for the Soufriere Hills eruption means local people can return home safely

Geoff Wadge, University of Reading working with British Geological Survey

Soufriere hills fig 1
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From 27 to 28 July 2008 Soufriere Hills Volcano, Montserrat experienced an intense swarm of long-period seismicity that culminated in an explosion and eruptive column collapse. The resultant pyroclastic flows set buildings alight in the remnants of Plymouth, the largely destroyed former capital. Together with R. Stewart (Acting Director of the Montserrat Volcano Observatory), Professor Wadge activated the International Charter for Space and Major Disasters via the Cabinet Office on 29 July to obtain the most up-to-data remotely sensed data on the state of the volcano. The volcano was covered in cloud and so the effects of the explosion on the stability of the large lava dome could not be determined visually.  By 1 August we had obtained high-resolution X-band radar images from the TerraSAR-X satellite that, together with earlier, equivalent data, were able to show the source and scale of the explosion’s effects on the lava dome. The Montserrat government’s civil protection committee were informed of this and were able to revoke the precautionary evacuation of people at risk from the dome on 6 August, a week or so before the dome was next seen by eye. 

References
Ager, G., Wadge, G.,Tragheim, D., Jordan, C. (2008) Volcanic eruption of 29th July 2008 on the island of Montserrat. Charter final operation report. Charter for Space and Major Disasters, Charter ID:213, British Geological Survey Report no. CR/08/179, 48pp.

Soufriere hills fig 2
Click on image to see more detail.

TerraSAR-X change difference radar image, showing the changes caused by the eruption of 28 July 2008. The small area of cyan colour is the Gages Wall vent of the volcano that was the source of the explosion. Pyroclastic flows of pumice flowed east and west from this vent and the magenta coloured area in this image shows the western flow which extended  4 kilometres into the abandoned former capital Plymouth. The still-populated area at risk from the eruption lies to the north in the Belham Valley.