基于地震活动性资料估计鄂尔多斯块体周缘构造断层面倾角

本文以鄂尔多斯地区为研究对象,探讨了基于地震参数的鄂尔多斯周缘构造几何产状的研究方法.首先,以全国活动构造图为基础,结合地震活动性,确定了鄂尔多斯地区的地表活动构造分布图.其次,对这些活动断裂截取剖面,通过地震震源分布,运用最大似然估计法确定断层面的倾角.最后,结合震源机制解以及地质资料验证了所估计的倾角的可靠性.期望本文建立的鄂尔多斯地区断层几何模型,能为基于GPS观测开展该地区断层滑动速率反演、强震发震构造及强震危险性预测模拟等提供基础.

Estimate of dip angles of faults around Ordos Block based on earthquakes

We discuss the method of defining geometric shape of faults around Ordos Block based on earthquake location results. First, based on tectonic map of China, we construct the active fault distribution of Ordos in accordance with seismicity. Then, we obtain the section plane of each fault, draw the location result of earthquakes on it and use the maximum likelihood method to calculate dip angles of each fault. Last, to analyze the reliability of dip angles, we combine focal mechanism solutions and geological data to make comparison. The geometric fault model of Ordos we construct in this study could be the basic work of further research, like the inversion of fault slip rates based on GPS observation, seismo-tectonic of strong earthquakes and seismic hazard simulation and assessment of this area.