最大噴気直径を利用した火山噴気放出量及び放熱量測定法

抄録

A quantitative analysis method to estimate steam and heat discharge rates by remote sensing technique was developed, based on the theory of diffusion of volcanic steam. The visible maximum diameter of volcanic steam is related to the full width half maximum of the steam density distribution. The steam density at the center of the visible maximum diameter can be derived theoretically assuming Gaussian distribution of steam density. So, we can calculate the volcanic steam discharge rate, if we also know the velocity of rising steam. To realize the theory, we developed an analyzing system based on the theory using compact video camera and personal computer. This system can deal with many data of video pictures in a short analyzing time. To confirm the effectiveness of the method, we applied it to an actual steam well and obtained good coincidence between steam discharge rates from the new remote sensing method and the conventional direct method. We also applied the remote sensing method to estimate steam and heat discharge rates from an active volcano of which steam and heat discharge rates are known. As a result, we obtained reasonable values from the volcano.