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本文探讨了用P波频谱研究正交和斜交震源破裂方式的方法。计算和分析了正交和斜交双侧、三侧破裂P波远场理论位移谱,并采用网格尝试法确定震源参数,研究了邢台地区1966年3月8日马兰6.8级地震和1966年3月22日东汪6.7级地震的破裂过程。研究结果表明:马兰地震的破裂方式是斜交三侧破裂。北北东方向为主破裂,破裂长度约29公里,其北东端在3月22日7.2级主震震区附近。东旺地震的破裂方式是正交三侧破裂,南南西方向为主破裂,破裂长度约23公里。另两侧破裂分别指向北西西方向,即8分钟后的7.2级主震方向及北北东方向,即四天后发生的6.5级百尺口地震的方向,虽然破裂规模较小(分别为10公里及6公里),但对其后这两地震的发生起了促进作用。这两地震的结果与余震震中分布图中显示的图象均很相象。
In this paper, the method of using P-wave spectrum to study the mode of orthogonality and skewed source rupture is discussed. Calculated and analyzed the theoretical displacement spectrum of the far-field and far-off P wave in orthogonality and skewed planes, and determined the source parameters by using the grid method. The earthquake of Mänin on March 8, 1966 in Xingtai region and the earthquake of 1966 March 22 Dongwang earthquake 6.7 earthquake rupture process. The result shows that the rupture of Malan earthquake is rupture on three sides of skewness. North-east direction of the main rupture, rupture length of about 29 km, its north-east end in the March 22 earthquake near the main shock 7.2. Dongwang earthquake rupture is orthogonal to the three sides rupture, mainly ruptured south-southwest, rupture length of about 23 km. The ruptures on the other two sides point northwest and west respectively, that is, the direction of the 7.2-magnitude main shock after 8 minutes and the north-northeast direction, that is, the direction of the 6.5-magnitude Bajikoukou earthquake occurred four days later. Though the rupture scale is small (10 km And 6 km) but contributed to the subsequent occurrence of these two earthquakes. The results of these two earthquakes are very similar to the images shown in the epicenter distribution of aftershocks.