| Abstract |
Geothermal energy is relatively clean. For this reason, it is one of the important energy resources for us, although the scale is not so large. The usable energy is stored generally as hydrothermal fluid occupying underground fractures and/or pores. This implies that it is the most important to know the 3-dimensional shape of the geological and geothermal structures for the exploration of it. Many geological and geothermal data collected during the exploration are analyzed by various procedures, and are displayed as geological and isotherm maps, and so on. Each map is always drawn on a Z-dimensional sheet. The 3-dimensional shape of the accurate structure is constructed only within the brain of the exploration engineer who treated most of data. If the other engineer wishes to know the 3-dimensional structure, he must spend a lot of time to understand the presented maps. On the contrary, if the engineer can use the suitable stereographic tool, he should easily understand the3-dimensional structure. A computer system for the stereography has been developed for the above purpose. The system possess functions necessary to observe interactively 3-dimensional geological and geothermal structures. That is, it can display quickly desirable figures from all directions. The application of this system to the Nishiyama geothermal filed is stated in the following chapters. |