[Abstract]

Using commercial Windows PC and digital cameras, we have developed an automatic image recording system, which is inexpensive, small and lightweight. This system automatically records camera images in a digital form and transfers them to a remote server through telephone lines. This system can be flexibly applied to the observation and monitoring of eruption columns even under severe conditions. With this system we have recoded images of the eruption columns of Miyakejima Volcano, Japan, every 10 seconds from 12 August 2000 to 13 May 2002. These images revealed how the vents of volcanic gas ejection developed during August 2000. The images after September 2000 showed that the column was relatively high in summer, probably reflecting the amount of vapor in the ambient atmosphere. Keywords: image recording system, Miyakejima eruption, eruption columns, vents development, vapor in the ambient atmosphere

e-mail:

terada@eos.hokudai.ac.j