Fig. 1. (A) Study area (green solid rectangle) locates in the western part of the Gyeonggi Massif, middle part of the Korean peninsula. CFS: Chugaryung Fault System, YSF: Yangsan Fault, GY: Gyeongju earthquake, PO: Pohang earthquake. (B) The NNE-SSW directing Chugaryung Fault System (CFS in A) is composed of several fault lines numbered by 1 ~ 7. Gravity stations in the study area were about 5,000 points, which are indicated by green dots. (C) The Annual frequency of earthquake registered in the study area shows a clear difference before and after the Gyeongju earthquake (black rectangle). The annual earthquake frequency after the Gyeongju earthquake increased rapidly to more than 4 times.

Econ. Environ. Geol. 2021;54:743-52 https://doi.org/10.9719/EEG.2021.54.6.743

© 2021 Econ. Environ. Geol.