We study the ground motion simulations based on three finite-source models for the 2007 Mw6.6 Niigata Chuetsu-oki, Japan, earthquake in order to discuss the performance of the input ground motion estimations for the near-field seismic hazard analysis. The three models include a kinematic source inverted from the regional accelerations, a dynamic source on a planar fault with three asperities inferred from the very-near-field ground motion particle motions, and another dynamic source model with conjugate fault segments. The ground motions are calculated for an available 3D geological model using a finite-difference method. For the comparison, we apply a goodness-of-fit score to the ground motion parameters at different stations, including the nearest one that is almost directly above the ruptured fault segments. The dynamic rupture models show good performance. We find that seismologically inferred earthquake asperities on a single fault plane can be expressed with two conjugate segments. The rupture transfer from one segment to another can generate a significant radiation; this could be interpreted as an asperity projected onto a single fault plane. This example illustrates the importance of the fault geometry that has to be taken into account when estimating the very-near-field ground motion.

中文翻译：

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从动态破裂建模的角度看地震学的不规则性：2007年日本中越冲绳Mw6.6地震。

我们研究了基于三种有限源模型的2007年日本新泻州中越冲绳Mw6.6地震的地震动模拟，以讨论输入地震动估算在近场地震灾害分析中的性能。这三个模型包括从区域加速度反转的运动学源，从近场地面运动粒子运动推断出的具有三个凹凸的平面断层上的动态源以及具有共轭断层段的另一个动态源模型。使用有限差分方法为可用的3D地质模型计算地面运动。为了进行比较，我们对不同站点的地面运动参数应用了拟合优度评分，包括最近的一个几乎在破裂断层段正上方的参数。动态破裂模型显示出良好的性能。我们发现，可以用两个共轭线段表示单个断层平面上的地震推断的地震凹凸。从一个片段到另一个片段的破裂转移会产生大量的辐射。这可以解释为将粗糙投影到单个断层平面上。该示例说明了估算极近场地面运动时必须考虑的断层几何形状的重要性。