Earthquake Prediction Research by Means of Telluric Potential Monitoring

为了检验VAN方法在地震预报中的适用性，在全国12个NTT大跨度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。研究了特什里亚加海峡2号(特什卡加-尼吉贝苏偶极子)上出现的异常电位变化的性质，并与久路附近地区的地震活动进行了对比。我们在尼吉贝图初中安装了一个短跨度的网络，在N-S和E-W方向上分别有50米和100米长的偶极子。用NTT大跨度偶极子在6-10月进行了同步观测。上述异常变化也出现在短跨度偶极子上。因此，问题中的异常变化不是由于NTT系统的噪声造成的。现在看来，这些潜在变化中至少有一部分是真正的先兆。为了弄清区域地下电导率的分布，进行了区域调查。在NTT的全力配合下，在7-11月期间，在25点进行了大跨度大地电势测量。

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.