【摘要】 海原断裂是中国西部的一条重要活动走滑断裂带 ,192 0年沿该带发生的 8.5级大震形成了长达 2 30km的地表破裂带和 10m的左旋走滑位移 .近 10余年来 ,国内外学者对海原断裂开展了古地震研究 ,揭示出大量的古地震事件 ,为研究该断裂带上强震复发规律提供了重要的基础资料 .本文利用这些古地震资料 ,采用泊松模型和布朗过程时间模型 (Brownianpas sagetimemodel) ,并考虑海原断裂带 3个段落组合的不同尺度的破裂 (单段破裂、双段破裂和全带破裂 ) ,经加权分析计算得到了海原断裂带未来百年强震 (M≥ 6 .7)复发的可能性及其震级分布 .计算结果表明 ,海原断裂带未来百年M≥ 6 .7地震发生的可能性为 0 .0 35 .更多还原

【Abstract】 The Haiyuan fault is a major strike-slip active fault in north-central China, along which Haiyuan earthquake with magnitude 8.5 occurred in 1920, and produced a 230 km long surface reupture zone with a maximum left-lateral displacement of 10 m. In recent years, some researchers have studied the paleoearthquake along the Haiyuan fault and revealed a lot of paleoearthquake events. All available information allows more reliable analysis of earthquake recurrence interval and earthquake rupture patterns along the Haiyuan fault. Based on this paleoseismological information, the recurrence probability and magnitude distribution for M≥6.7 earthquake in future 100a along the Haiyuan fault can be obtained through weighted computation, by using Poisson and Brownian passage time models and considering different rupture patterns. The result shows that the earthquake probability of M≥6.7 is about 0.035 in 100-years along the Haiyuan fault.更多还原