【摘要】 通过岩石高温高压破裂实验与有机玻璃破裂试验的应力-应变曲线对比、地震波形记录(观测资料)与试样破裂波形(实验资料)对比、地震前后定点应变与主破裂前后应变形态变化的对比,认为慢地震是临界或亚临界破裂或预先滑动所致,是低频应变波动。它是材料屈服、弱化或塑性变化的必然结果。而慢前兆则是临近大地震(大破裂)前出现的诸如形变、低频地震波(破裂弹性波)等的短期及临震前兆现象,它比较可靠。但由于许多岩石主破裂前并无明显的临界破裂或预滑动现象,也并非所有岩石都一定出现明显屈服,所以也并非每个地震前都有慢地震,因此,也就不一定都出现低频波动。从而,也并不一定都出现相同的短期、临震前兆现象。更多还原

【Abstract】 By comparing the stress-strain curves of rock samples at high temperature and high pressure with ones of plexiglas at usual temperature and axial compression, and contrasting seismic wave with ones recorded when fracture occurs in the sample , and balancing the fixed-point strain of pre- and post-earthquake with the variation of strain field pre- and main-fracture of rock sample, we understand that slow earthquake results from critical or sub-critical fracture, or pre-slid, and it is a strain wave with low frequency. It is an inevitable result due to material yield, weakening or plastic variation. The slow precursor is a sort of credible, short-term and impending precursors, such as deformation, strains wave with low frequency before the large earthquake (large fracture). Since the obvious critical-or sub-critical fracture, pre-slid or obvious yield was not observed before the fracture in all rocks, therefore, there won’t be slow earthquake and the wave with low frequency before all strong earthquakes. As a result, the same short-term and impending precursor is not observed before all strong earthquakes.更多还原