强震前近震中区地电场异常研究

Geoelectric Field Ratio Anomalies near Epicenter Area before Earthquakes

摘要:

对国内地电场观测的分析结果表明，地电场观测资料中存在着各种不规则的扰动变化和多种频谱的周期性变化，这种与地磁场或者固体潮正常变化相关的电场变化和地震前兆变化混杂在一起，很难从原始资料中识别和提取地震前兆信息。考虑到与地震有关的近场变化对地震预测的研究更具实际意义，本文中选取了汶川、玉树地震震源区附近的39个台站和文安地区12个台站的地电场观测资料，通过计算同台、同测向观测资料的长、短极距测值的比值对地震前兆信息进行分析、研究。结果表明，震中区的多数台站地电场的比值震前存在不同形态的异常变化。

Abstract: The analysis of geoelectric observation in Chinaindicates that geoelectric data contain various irregular changes and multiform spectrum periodic changes. These changes are correlated with normal geomagnetic field or earth tide and mixed with seismic precursor information, which make it difficult to detect and extract seismic precursor information from raw data. Considering that changes in near field are more significant to earthquake prediction, the data from 39 stations near the epicenter area of Wenchuan and Yushu earthquake and 12 near the epicenter area of Wen’an earthquake have been collected in order to calculate the ratio for further research using the long and short dipole distance observation data in the same direction of the same station. The result indicates that most of the stations appear ratio anomaly with different shape before an earthquake in the epicenter area.