The ML 5.8 earthquake that jolted Gyeongju in southeastern Korea in 2016 was the country’s largest inland event since instrumental seismic monitoring began in 1978. We developed dynamic rupture models of the Gyeongju event constrained by near‐source ground‐motion data using full 3D spontaneous dynamic rupture modeling with the slip‐weakening friction law. Based on our results, we propose two simple dynamic rupture models with constant strength excess (SE) and slip‐weakening distance (⁠Dc⁠) that produce near‐source ground‐motion waveforms compatible with recorded ones in the low‐frequency band. Both dynamic models exhibit relatively large stress‐drop values, consistent with previous estimates constrained by source spectrum analyses. The fracture energy estimates were also larger than those predicted by a scaling relationship with the seismic moment. The dynamic features constrained in this study by spontaneous rupture modeling and waveform comparison may help understand the source and ground‐motion characteristics of future large events in southeastern Korea and thus the seismic hazard of the region.

中文翻译：

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2016 ML 5.8 韩国庆州地震的动态破裂模型，受运动破裂模型和地震波形数据约束

2016 年在韩国东南部庆州发生的 ML 5.8 地震是自 1978 年开始仪器地震监测以来该国最大的内陆地震。我们使用全 3D 自发动态破裂，开发了受近源地面运动数据约束的庆州事件的动态破裂模型使用弱滑摩擦定律进行建模。根据我们的结果，我们提出了两个简单的动态破裂模型，具有恒定的超强度（SE）和滑移弱化距离（⁠Dc⁠），产生与低频段记录的波形兼容的近源地震动波形。两种动态模型都表现出相对较大的应力降值，与之前受源谱分析约束的估计一致。断裂能估计值也大于通过与地震矩的比例关系预测的值。本研究中通过自发破裂建模和波形比较所限制的动力特征可能有助于了解韩国东南部未来大型事件的震源和地面运动特征，从而了解该地区的地震危险性。