9418770 Dehn This award supports a 12-month Science and Technology Agency of Japan Postdoctoral Fellowship for Dr. Jonathan Dehn at the Geological Survey of Japan, Sapporo, Japan. Dr. Dehn will work with Dr. Takarada at the Hokkaido Branch on a research project entitled, "Japan STA Program: Computer Modeling of Volcanic Eruptions." The modeling of a volcanic system from eruption to deposition has been missing in volcanology. Dehn and Takarada will study the volcanogenic particles created during low energy volcanic eruptions throughout Japan. This data will be used to formulate modular quantitative models of the eruptions. Each physical component of the volcanic eruption will be modeled including vesiculation, fragmentation, ejection, subaerial transport, subaqueous transport, deposition, deformation, secondary fragmentation and mass wasting. The research team will develop a modular computer program for each component which can be added or deleted from the whole model in order to simulate nearly any volcanic condition. This model would be an important basis for comprehensive modeling of volcanic systems, and could be come a useful tool not only in the understanding of active systems but also in interpretation of ancient volcanoes and their deposits. The model would be of great use in volcanic hazard determination as well as modeling of eruptions on other planets. ***