In this study, we investigate the source rupture process of the 2018 Hokkaido Eastern Iburi earthquake in Japan ( M JMA 6.7) and how the ground motion can be reproduced using available source and velocity models. First, we conduct a multiple-time-window kinematic waveform inversion using strong motion waveforms, which indicates that a large slip area located at a depth of 25–30 km in the up-dip direction from the hypocenter was caused by a rupture propagating upward 6–12 s after its initiation. Moreover, the high-seismicity area of aftershocks did not overlap with the large-slip area. Subsequently, using the obtained source model and a three-dimensional velocity structure model, we conduct a forward long-period (< 0.5 Hz) ground-motion simulation. The simulation was able to reproduce the overall ground-motion characteristics in the sedimentary layers of the Ishikari Lowland.

中文翻译：

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2018年日本北海道伊武里东部地震震源过程估算及长周期地震动正演模拟

在这项研究中，我们调查了 2018 年日本北海道东部伊布里地震 (M JMA 6.7) 的震源破裂过程，以及如何使用可用的震源和速度模型再现地面运动。首先，我们使用强运动波形进行了多时间窗口运动学波形反演，这表明位于震源上倾方向 25-30 km 深度的大滑移区是由向上传播的破裂引起的。启动后 6-12 秒。此外，余震高震区与大滑移区不重叠。随后，使用获得的震源模型和三维速度结构模型，我们进行了前向长周期（< 0.5 Hz）地震动模拟。