基岩断层面的古地震研究

古地震研究是获得较为完整地震记录、拓展地震记录历史的最有效方法，目前最常用的探槽技术无法解决基岩区活动断层的古地震研究难题。本项目将在“高精度断层面形貌学定量研究（40872128）”和“断层面形貌几何特征与破裂过程的相关性研究（41372210）”的基础上，采用高精度断层面形貌分析技术和宇宙成因核素测年技术，开展基岩断层面的古地震研究。连续的风化侵蚀作用和周期性的地震活动造成基岩断层面的显著垂直分带性，每个分带都与地震相关；基于形貌分析技术获得的分带的形貌特征参数、宇宙成因核素测年技术获得的分带的暴露年龄，拟合断层面形貌特征与暴露时间的相关关系；根据这一相关关系，获取目标断层的古地震系列和研究区的地震时空分布规律；最后，结合探槽古地震研究成果，构建研究区和目标断层的强震复发模型。

Paleo-earthquake research is the most effective method to obtain relatively complete seismic records and expand the history of seismic records. At present, the most commonly used trenching technique cannot be used to do paleo-earthquake research in bedrock areas. This project will use a fault surface morphology Based on “Quantitative study of high-resolution fault surface morphology (40872128)” and “Relationship between morphologic characteristics of a fault surface and rupture process (41372210)”, we will make a study of paleo-earthquake on bedrock fault surface, using high-precision morphologic analysis and cosmogenic nuclides dating techniques. Continuous weathering and periodic seismic activity result in significant vertical zoning of bedrock fault surface, and each zoning band is related to an earthquake. The correlation between the morphologic parameter and exposure age is fitted based on the morphologic analysis and cosmogenic nuclides dating of several test fault surface. According to this correlation, we obtain the paleo-earthquake series of the target fault and the earthquake spatio-temporal distribution in the study area. Finally, combined with the results of previous trenching paleo-seismological researches, we construct a recurrence model of strong earthquakes to the test study area and target faults.