Two M 5 earthquakes struck the southeastern Korean Peninsula in September 2016 and November 2017, causing damage near the epicentral areas.We analyze the stress-drop scaling of these two earthquake sequences using coda-based methods and Bayesian inversion. The 2016 Gyeongju earthquake sequence is a typical earthquake sequence generated by tectonic processes. In contrast, the 2017 Pohang earthquake sequence is believed to be related to fluid injections conducted for the development of enhanced geothermal systems. As the two sequences occurred in the same tectonic regime, our study provides a good opportunity to compare the stress-drop scaling between a tectonic earthquake sequence and an earthquake sequence influenced by fluid injections. We found that the stress drops of events in the Pohang sequence are lower than those of the Gyeongju sequence with similar magnitude. Although it is likely that this difference results from focal depth variations, a reduction of stress drop due to fluid injections cannot be ruled out.

中文翻译：

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使用基于尾声的方法对 2016 年庆州和 2017 年浦项地震序列的应力降标度

2016 年 9 月和 2017 年 11 月，朝鲜半岛东南部发生了两次 M 5 级地震，在震中区附近造成破坏。我们使用基于尾声的方法和贝叶斯反演分析了这两次地震序列的应力降标度。2016年庆州地震序列是构造过程产生的典型地震序列。相比之下，2017 年浦项地震序列被认为与为开发增强型地热系统而进行的流体注入有关。由于这两个序列发生在同一构造体系中，我们的研究提供了一个很好的机会来比较构造地震序列和受流体注入影响的地震序列之间的应力降尺度。我们发现浦项序列事件的应力降低于具有相似震级的庆州序列。尽管这种差异很可能是由焦深变化引起的，但不能排除由于流体注入而导致的应力降降低。