Earthquake Prediction Research by Means of Telluric Potential Monitoring

为了检验地震预报VAN方法的适用性，在全国12个NTT长跨距台站进行了大地电位连续观测。此外，在最有希望的Teshikaga站周围地区进行了地方和区域特别调查。当地的调查是为了研究出现在Teshiliaga通道2（Teshikaga-Nijibetsu偶极子）上的异常电位变化的性质，并可能与钏路附近地区的地震活动有关。我们在二别初中安装了一个短跨度网络，在南北和东西两个方向上都有50米和100米长的偶极子。在6月至10月期间，与NTT长跨距偶极子进行了同步观测。这种反常变化也出现在短跨距偶极子上。因此，所讨论的异常变化不是由于NTT系统的噪声。现在看来，这些潜在的变化中至少有一部分可能是真实的前兆。为弄清区域地下电导率的分布规律，进行了区域性调查。在NTT的全力配合下，7月至11月期间，在25.

To test the applicability of the VAN-method of earthquake prediction continuous observation of telluric potential was conducted at 12 NTT longspan stations scattered over the country. Moreover, both local and regional special investigations were made in the area surrounding the most promising Teshikaga station. The local investigation was made to study the nature of the anomalous potential changes which appear on Teshiliaga channel 2(Teshikaga-Nijibetsu dipole), and may be correlated with seismicity of the region off Kushiro. We installed a short-span network with 50m and 100m long dipoles in both N-S and E-W directions at the Nijibetsu Junior High School. Simultaneous observation with the NTT long-span dipoles was conducted during June-October. The anomalous changes in question appeared on the short-span dipoles also. Therefore, the anomalous changes in question are not due to noise from the NTT system. It now seems probable that at least some of these potential changes are real precursors. The regional investigation was made to clarify the regional subterranean electrical conductivity distribution. With a full cooperation of NTT, during July-November, long-span telluric potential measurement was conducted at 25.