华北地区地震序列参数的分布特征

为系统地考察华北地区地震序列参数的分布特征，以期构建适合区域地震活动特征的短期概率预测模型和评估地震危险性，本文利用当前较为前沿的ETAS模型和R-J模型，采用连续滑动、多时段拟合的方式，对华北地区1970年以来的16个地震序列进行了参数拟合，并对参数的整体情况、参数之间的关系、参数与大地热流之间的关系等特征进行了分析研究.研究结果表明，主震发生后的早期阶段，地震序列参数变化相对较为剧烈，误差也较大；两种地震预测模型的序列参数呈现出一种优势分布特征，主要参数的平均值分别为α_ETAS=1.7404±0.3420，p_ETAS=0.9769±0.1396，a_OML=-1.6638±0.5284，b_OML=0.8312±0.1658，p_OML=0.9053±0.1527，这与国际上其他区域的研究具有很强的一致性；大多数情况下，ETAS模型参数p_ETAS高于R-J模型参数p_OML，平均偏高0.0716；序列参数α_ETAS与大地热流值整体上呈现一种负相关关系，激发次级余震的能力与大地热流具有一定的相关性.地震序列参数的分布特征以及与大地热流之间的关系对地震序列类型的判断，及基于地震序列参数构建定量化的短期概率预测模型，均有重要的应用价值.

Distribution characteristics of earthquake sequence parameters in North China

The purpose of this work is to systematically examine the distribution characteristics of earthquake sequence parameters in North China, which is helpful in establishing a short-term probability prediction model and assessing seismic hazard suitable for regional seismicity. Using currently advanced ETAS and R-J models and continuous sliding and multi-period fitting, the parameters for 16 earthquake sequences since 1970 in North China are fitted, and some parameters characteristics are analyzed such as the overall state of the parameters, the relationship between the parameters and the relationship between the parameters and the terrestrial heat flow. Results show intense changes and large errors in the early stage after the occurrence of the main shock. The sequence parameters of the two earthquake forecasting models exhibit a dominant distribution characteristic. The average values of the main parameters are α_ETAS=1.7404±0.3420,p_ETAS=0.9769±0.1396,a_OML=-1.6638±0.5284,b_OML=0.8312±0.1658,p_OML=0.9053±0.1527, which are highly consistent with those in other regions of the world. In most cases, the ETAS model parameter p_ETAS is higher than the R-J model parameter p_OML, with an average difference 0.0716. Sequence parameter α_ETAS and heat flow are of a negative correlation and the capability of stimulating secondary aftershocks have certain correlation with terrestrial heat flow. Understanding the distribution characteristics of earthquake sequence parameters and their relationship with the heat flow would help to better determining the type of earthquake sequence and constructing a quantitative short-term probability forecasting model based on earthquake sequence parameters.