Content of research

○ For geothermal resource development, which has been actively promoted in recent years, geothermal reservoirs are examined through base structure surveys. We have been investigating the basement structure through gravity surveys, precise seismic source distribution, and seismic velocity structure analysis.
○ For geothermal power generation, steam is produced and hot water is returned to the underground, but it is necessary to monitor the level of the geothermal reservoir to ensure the sustainable use of resources. We will examine the appropriate resource utilization volume through physical assessment of the subsurface fluid conditions using precise gravity measurements and crustal deformation observations.
○ The injection of high-pressure fluids into geothermal wells may induce noticeable tremors and cause problems. We will provide guidelines for appropriate and sustainable resource development by developing a method to evaluate the risk of induced earthquakes based on such parameters as the crustal stress state in the geothermal development area, surrounding faults, the characteristics of the seismic activity, and fluid injection volume.

Potential for social implementation

• ・Surveys of potential hot spring resources
• ・Monitoring and evaluation of hot spring resources
• ・Evaluation of potential geothermal resources
• ・Assessment of the impact of subsurface disposal of carbon dioxide (CCS)
• ・Evaluation of earthquakes induced by oil development
• ・Drilling well design through stress field analysis

Appealing points to industry and local governments

The results of earthquake and crustal movement research can be used to monitor geothermal reservoirs required for geothermal power generation projects.
To proceed with development and commercialization while obtaining an understanding of the local community, we have to respond to the social demand to quantitatively evaluate the risk of earthquakes induced by geothermal development to control their occurrence. We will propose risk assessment methods based on resource monitoring using our knowledge of volcanology and seismology.