【摘要】 通过对１９７６ 年唐山７．８ 级地震后的较强余震（１９７８ 年以后ＭＬ≥４．９）与华北中强地震的对比分析，发现唐山较强余震的发生与华北中强地震具有较好的相关性，并给出了对应概率。为预测未来唐山显著地震提供了定量依据。更多还原

【Abstract】 By comparative analysis of the relatively strong after shocks( M L ≥4.9 after 1978)after the Tangshan M7.8earthquake in 1976 and the moderately strong earthquakes in North China area,it is found that the relatively strong after shocks in Tangshan show a correlatability with the moderately strong earthquakes in North China area,and the corresponding probability has been given which has provided a quantitative basis for the prediction of notable earthquakes occurred in Tangshan in the future.更多还原