Measurement of Seismic Wave Using Vertical Earth Potential Difference Method and Its Wavelet Analysis

垂直地电位差法地震波测量及其小波分析

• 批准号: 07650467
• 负责人: TAKEUCHI Nobunao
• 金额: $ 1.41万
• 依托单位: Tohoku University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 1995
• 资助国家: 日本
• 起止时间: 1995 至 1996
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-07650467/
• 关键词: KOBE EARTHQUAKE; EARTHPOTENTIAL; EAST OFF HOKKAIDO EARTHQUAKE; SEISMIC WAVE; REFERENCE ELECTRODE; STREAMING POTENTIAL; 照合電極; 落雷位置評定; 地電位差計測; ウェブレット変換; 垂直方向地電位差

To observe the earth potential difference (EPD) signals induced by seismic waves a modified method, measured in the vertical direction underground, has been operated continuously at Aobayama in Sendai. This method is succsesfully used to reduce the unnecessary signals induced by artificial and natural earth current sources. On all earthquakes of more than I Japanese intensity scale we can clearly observe EPD signals. The P-wave arraival times agree quiet well with ones obtained by meteorological agency seismograph. Though less than 1 scale in Sendai the EPD signals of the Southen Hyougo Prefecture earthquake (the Kobe eartquake) have been clearly recorded in this method.The EPD signals are observed at three vertical different positions underground in the Aobayama site. We have following characteristics of the earth electric field underground induced by seismic waves, (1)the electrical field in the vertical direction is higher than in the horizontal direction by one order, (2)this field increases repidly coming up to the ground surface.We have obtained the seismic waveform records from the Earthquake Obsrervatory of Tohoku University which is located apart 700m from the Aobayama site. Spectrum analysis has been performed for both wave records. Of accelaration, velocity and displacement of the earth, the EPD signal seems to be proportion to the earth accelaration signal. We estimate the ratio of electric field to pressure drop in the earth. This ratio is reasonable on the assumpution of the streaming potential which is induced by the earth accelaration.

为了观测地震波引起的地电位差（EPD）信号，在仙台青叶山连续进行了一种改进的方法，在地下垂直方向上进行了测量。该方法已成功地用于消除人工和自然地电流源引起的不必要信号。在所有超过日本强度等级I的地震中，我们都可以清楚地观察到EPD信号。P波到达时间与气象局地震仪记录的P波到达时间吻合较好。用这种方法，在仙台不到一个标度的情况下，对日本兵库县南部地震（科比地震）的EPD信号进行了清晰的记录。地震波在地下引起的大地电场具有以下特点：（1）垂直方向的电场比水平方向的电场高一个数量级，（2）到地表时电场迅速增大。对这两个波记录进行了频谱分析。在地球加速度、速度和位移中，EPD信号似乎与地球加速度信号成正比。我们估计了地球中电场与压降的比值。这一比值对计算地球加速度引起的流动电位是合理的。

项目成果

竹内伸直: "北海道東方沖地震の直前後における雷活動と電位差微少変動信号" 電気学会論文誌C分冊. 116巻6号. 719-724 (1996)

No. Takeuchi：“北海道东部近海地震前后的闪电活动和电位差微小波动信号”，日本电气工程师学会学报，第 116 卷，第 6 期，719-724（1996 年）

N.Takeuchi: ""Long Term Observation of Earth Potential Difference and its Relationship with Electro-Static Field at Ground Surface (Qualitative Analysis of Micro Variation in Earth Potential Difference)"" The Transactions of The Institute of Electrical En

N.Takeuchi：“大地电位差的长期观测及其与地表静电场的关系（大地电位差微变化的定性分析）”《电气工程研究所学报》

竹内伸直: "北海道東方沖地震の直前後における雷活動と電位差微小変動信号" 電気学会論文誌C分冊. 116巻6号. 719-724 (1996)

Nobuaki Takeuchi：“北海道东部近海地震前后的闪电活动和电位差微小波动信号”，日本电气工程师学会学报，第 116 卷，第 6 期，719-724（1996 年）

N.Takeuchi: ""Lightning Activity and Earth Potential Difference signals about the East Off Hokkaido Earthquake"" The Transactions of The Institute of Electrical Engineers of Japan. Vol.116-C,No.6. 719-724 (1996)

N.Takeuchi：“北海道东部地震的闪电活动和地电位差信号”，日本电气工程师学会会刊。

N.Takeuchi: ""Characteristics of Earth Potential Difference Generations by Seismic Wave"" The Transactions of The Institute of Electrical Engineers of Japan. Vol.116-C,No.9. 1064-1069 (1996)

N.Takeuchi：“地震波产生的地球电位差的特征”，日本电气工程师学会会刊。