A DYNAMICAL MODEL OF A GEYSER INDUCED BY BOILING: AN APPLICATION OF THE DYNAMICAL MODEL OF A GEYSER INDUCED BY INFLOW OF GAS

Hiroyuki Kagami, Department of Preschool Education, Nagoya College, Japan

Abstract

 
We have proposed a static model, a dynamical model and a modified dynamical model of a geyser induced by inflow of gas based on observation and model experiments of it and have also proposed a combined model combining above two models. And numerical simulations of the modified dynamical model or the combined model reappear spouting dynamics of a geyser induced by inflow of gas and it becomes possible that parameters (volume of the underground space, depth of spouting hole and so on) under a geyser are estimated due to comparison between results of simulation and those of observation. Moreover we proposed a dynamical model which assumed more than two underground gas supply sources by extension of above-mentioned usual dynamical model. As a result, irregular spouting dynamics of a geyser induced by inflow of gas could also be reappeared by the modified model. As a result, spouting mechanism of all kinds of geysers induced by inflow of gas, that is, that of not only regularly spouting geysers but also irregular spouting geysers has been clarified.
However, in general, geysers are classified into two types dependent on inducer. That is, one is a geyser induced by inflow of gas and the other is a geyser induced by boiling. The latter is more popular and many ones exist all over the world. Though qualitative spouting models of a geyser induced by boiling have been proposed, its dynamics has not been discussed sufficiently. Therefore, in this study, we derive a dynamical model of a geyser induced by boiling applying the above-mentioned dynamical model of a geyser induced by inflow of gas. Then we try to estimate underground parameters of a geyser induced by boiling by comparison of results of numerical simulation of the model and those of observation of a geyser induced by boiling.
Moreover, this study also provides concrete and effective information based on which we take measures to protect geysers whose spouting dynamics (spouting period, reachable height during spouting and so on) have been gradually declining. If the declining geyser is dealt with suitably and the former spouting dynamics of it is maintained through effective use of this study, this will protect not only local people supported by tourists who visit there so as to see or use the geyser but also the precious environmental resources for us.