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| 地震前低频事件的实验研究 | |
| 引用本文： | 李世愚,唐林波,刘建新,和雪松,苏昉,孙为.地震前低频事件的实验研究[J].地震地磁观测与研究,2002,23(4):1-7. |
| 作者姓名： | 李世愚 唐林波 刘建新 和雪松 苏昉 孙为 |
| 作者单位： | 1. 中国北京,100081,中国地震局地球物理研究所;中国北京,100081,中国地震局构造物理开放实验室 2. 中国北京,102200,石油大学;中国北京,100081,中国地震局构造物理开放实验室 3. 中国北京,102200,石油大学 |
| 基金项目： | 本项研究得到科技部社会公益研究专项资金项目2001DIB20107,地震科学联合基金会的资助 |
| 摘 要： | 介绍了几种强震前超低频事件的观测证据,并通过实验,研究了产生和传播机理。初步结果表明,微破裂的集结和断层的破裂起始会出现超低频脉冲,并透射到空气中形成次声波。塑性体的冲击或超临界流体的膨胀比脆性破裂更容易激发（超）低频波,且不伴随明显高频辐射成分。这样可以较为合理地解释震前“平衡”背景下的（超）低频事件。对实验中破坏前的低频脉冲给出了断裂力学解释。断裂力学的实验和膨胀－－扩容理论证明了震前会产生断层的张裂隙,从而为超临界流体提供了运移空间。流体在运移过程中突然涨缩会激发（超）低频辐射波。讨论了改进（超）低频事件的观测条件问题。 |
| 关 键 词： | 地震前兆 超低频辐射 实验研究 次声波 地震成核 |
| 文章编号： | 1003-3246(2002)04-0001-07 |
| 修稿时间： | 2002年3月12日 |
Experimental investigation of precursory low-frequency events before strong earthquakes |
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| LiShiyu,Tang Linbo,Liu Jianxin,He Xuesong,Su Fang,Sun Wei.Experimental investigation of precursory low-frequency events before strong earthquakes[J].Seismological and Geomagnetic Observation and Research,2002,23(4):1-7. | |
| Authors: | LiShiyu Tang Linbo Liu Jianxin He Xuesong Su Fang Sun Wei |
| Abstract: | In this paper, some evidence from observation of precursory low-frequency events before strong earthquakes are presented, and the mechanism of producing and propagation is investigated experimentally. The primary results show that the ultra low-frequency pulses may produce in the process of nucleation of micro-cracks and faults, and transmit to the air as infrasonic sound. The plastic impact or the dilatancy of ultra-critical liquid can excite ultra low frequency easier without obvious high-frequency radiation. The phenomenon of low frequency pulses before failure of the sample is interpreted by using the theory of fracture mechanics. Theses results may interpret the low-frequency events under the "quiet" background before strong earthquakes more rationally. The experiments of fracture mechanics and the D-D theory prove that tensile cracks may be brought before earthquakes, and so as to offer the space of liquid transmission. In the process of transmission, the liquid may dilate and contract and excite(ultra) low frequency radiate wave. Besides, the improving of observation condition of low-frequency events is discussed. |
| Keywords: | earthquake precursors ultra low frequency experimental research infrasonic sound earthquake nucleation |
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