基于QSSP的震源破裂过程反演方法

在Qt平台上，基于QSSP软件，利用C⁺⁺进行地震破裂过程反演方法研究。采用按阶段反演的方法，第1阶段反演采用热浴算法进行全局搜索，先按断层区域的构造背景等初始条件对参数范围进行划取，在该范围内随机给定一组初始值开始迭代，使波形初步拟合避开局部最优解；第2阶段反演使用拟牛顿法进行快速收敛，提高波形拟合程度，迭代至目标函数小于误差条件时停止，输出满足误差条件的待解模型参数。为避免模型参数出现病态问题，使用拉普拉斯方程建立平滑矩阵并引入平滑因子对断层模型进行平滑约束。使用棋盘模型验证该方法的稳定性和可靠性。最后，将全国13个台站的重力数据积分后对2013-04-20芦山7.0级地震的破裂过程进行反演，并与其他研究结论进行对比分析。

Inversion Method of Source Rupture Process Based on QSSP

We use C⁺⁺ to apply an inversion method for source rupture of earthquakes on Qt platform based on QSSP software. The algorithm is divided into two stages. The first stage is a global search by heat bath algorithm, which consists of two steps. First, we divide the parameter range according to the initial conditions such as the tectonic background of the fault area. Second, we define random parameters at each range and start the iteration for making the preliminary waveform fitting avoid the local optimal solution. The second stage is a fast convergency by quasi-Newton algorithm, which improves the fitting level of waveform. In this stage, the iteration will stop until the result of objective function is less than the error, and output fits undetermined parameters. In this paper, to avoid the parameter ill-posed problem, we use the Laplace equation to establish the smoothing matrix, and the smoothing factor is introduced to smooth constraint on the fault model. In addition, we use checkerboard model to ensure the stability and reliability of the above method. At last, we reverse the rupture process of the Lushan M_S7.0 earthquake on April 20, 2013 using gravity data from 13 gravity stations, and compare with other research.