摘要
对于有代表性的八种岩石样品进行单轴压力实验,并着重于在载荷维持恒定及载荷刚一卸除的两个时间段内,观测岩石剩余磁化强度,应变,声发射等物理量随时间的变化。结果表明,参与实验的大部分样品剩余磁化强度在恒载期间仍有变化,且都保持与恒载前变化趋势一致,同时应变也有与恒载前相同趋势的变化。另外,在恒载结束、应力降至零后的最初阶段,剩磁及应变亦仍有变化。作者认为,以上现象是岩石流变性质的反映。对于无震期间地磁场变化以及大震前后地磁场的长期缓慢变化,都有过许多报导,用岩石压磁效应似不足以解释其中某些数量颇大的变化。与岩石流变性质相联系的磁效应,是另一种值得注意的可能机理。
An experiment of uniaxial compression on some pytical rock samples of 8 types is carried out, in which the remanent magnetization, strain and acoustic emission are recorded as the function of time and investigated especially for two periods, i. e. , under the constant loading and after unloading respectively. It is found that the remanent magnetization in 14 samples among total 16 still shows changes during constant loading and the tendency of these changes remains the same as that before the pressure keeping constant. In the mean time, the changes of strains are observed as well. On the other hand, in a short time period beginning at the end of unloading, the variations of remanent magnetization and strains are also observed. Above phenomena seem to be the reflection of Theological properties of rocks. It is interesting that some similar phenomena are observed in field, such as aseismic changes of geomagnetic field and secular variations of geomagnetic field before and after earthquakes. Some changes of rather large amounts are hardly explained by only piezomagnetic effect of rocks. The magnetic variation associated with Theological property of rocks is another possible mechanism of seismomagnetism which is worth notice.
出处
《中国地震》
CSCD
北大核心
1992年第2期53-60,共8页
Earthquake Research in China
基金
地震科学联合基金会资助课题
