Wadge, G., & Isaacs, M. C. (1988). Mapping the volcanic hazards from Soufriere Hills Volcano, Montserrat, West Indies using an image processor. Journal of the Geological Society, London, 145, 1988, pp. 541-551. Caption: Figure 9, p.549 "Sequential hazard zone of Soufriere Hills Volcano. Zone 1 is the earliest hazard zone affected by mudflows derived from the major fumaroles. Zones 2-7 represent those areas that would be covered by deposits from an eruption centred on Castle Peak dome that increased sequentially in strength by five increments."