Investigation of the Earthquake Prediction by the observation of Groundwater Radon Concentration at the Kamioka Mine, Gifu Prefecture

Gifu prefecture is located in the middle of Japan，and there are many active faults.We have carried out continuous monitoring of radon concentration，water flow rate，water temperature at20wells。We observed groundwater at the Wariishi hot spring，Kamioka，Gifu Prefecture。We made clear the relationship between the change of groundwater flow and the occurrence of earthquakes by using geological method。The average of radon concentration of the Wariishi hot spring was 2.54Bq/l with a liquid scintillation method。It is obvious from the analysis of the water flow rate using the BAYTAP-G that the water flow rate at the Wariishi hot spring has periodic fluctuations mainly induced by the Earth‘s tides.The water temperature went down by about1degree at the Wariishi hot spring eight hours before the series of earthquakes at the Nagano and Gifu boundary。And there was co-seismic phenomena at the Wariishi hot spring，where the water temperature went up about1.5 degrees，and the water flow rate increased by 79 liters per minute，from57liters per minute，after the Hida region Earthquake which had a magnitude of 5.4。The magnitude M is related to the distanceΔfrom the epicenter。As a result of the change of the water flow rate，when the three earthquakes，each of which had a magnitude of more than 6.6，and this earthquke occurred，the equality Mc≥2.3 logΔ+1.5 arose。Consequently the analysis of water flow rate demonstrated that the phase of K I D 21 I D 2，amplitude of O I D 21 I D 2 and K I D 21 I D 2 changed after this earthquake.

Gifu prefecture is located in the middle of Japan, and there are many active faults. We have carried out continuous monitoring of radon concentration, water flow rate, water temperature at 20 wells. We observed groundwater at the Wariishi hot spring, Kamioka, Gifu Prefecture. We made clear the relationship between the change of groundwater flow and the occurrence of earthquakes by using geological method. The average of radon concentration of the Wariishi hot spring was 2.54Bq/l with a liquid scintillation method. It is obvious from the analysis of the water flow rate using the BAYTAP-G that the water flow rate at the Wariishi hot spring has periodic fluctuations mainly induced by the Earth's tides. The water temperature went down by about 1 degree at the Wariishi hot spring eight hours before the series of earthquakes at the Nagano and Gifu boundary. And there was co-seismic phenomena at the Wariishi hot spring, where the water temperature went up about 1.5degrees, and the water flow rate increased by 79 liters per minute, from 57 liters per minute, after the Hida region Earthquake which had a magnitude of 5.4. The magnitude M is related to the distance Δ from the epicenter. As a result of the change of the water flow rate, when the three earthquakes, each of which had a magnitude of more than 6.6, and this earthquke occurred, the equality Mc ≧ 2.3log Δ +1.5 arose. Consequently the analysis of water flow rate demonstrated that the phase of KィイD21ィエD2, amplitude of OィイD21ィエD2 and KィイD21ィエD2 changed after this earthquake.