地震予知のための地下水テレメータ観測システム

抄録

Since the Tokai district was designated as an“ntensified Observation Area” in 1974, many kinds of observation for the purpose of earthquake prediction have been done by various institutes. Among them, automatic data collection and real time monitoring of the changes in groundwater level and radon concentration were started in 1976 by Geological Survey of Japan (GSJ). These data are automatically transmitted through the telephone line, and received by an engineering work station at GSJ, in Tsukuba. During these observation period, we have detected some ground water anomalies caused by earthquakes.
This system is constructed with taking the following points into account.
1) Water level is observed in pressured ground water. The ground water, that is sensitive to barometric pressure and earth tide, is expected fairly sensitive to an earthquake.
2) Radon is observed in self-flowing ground water, because it is difficult to control pumping power for non-self-flowing ground water and distinguish radon anomalies from pumping rate fluctuations.
3) Aiming low operation cost and flexibility of the system, data transmitting path has been changed from simple conventional telemetering equipment to computer communication. These computers on the observation sites are sampling data every 2 minutes, and transmitting data every hour.
4) The computer at data collecting center has been substituted from mini-computer system to engineering work station with LAN system. So, high quality data processing can be performed on specified independent computer system.