There has been an argument that the cause of earthquakes in Gyeongju and Pohang is massive rocks existing underground rather than the earth’s fault lines.
Research Group Geophysics and Geoinformation of the University of Kiel in Germany conducted underground surveys using three-dimensional imaging with gravity field values to map the regions under Gyeonju and Pohang.
Dr. Choi Sungchan (University of Kiel) said, “There is independent low-density cylindrical granite, and below it, there is LVZ (low-velocity zone) which could be very vulnerable to high-temperature ground.”
In other words, the earthquake that happened in Gyeongju and Pohang is specific to southeastern Korea, which is different from general earthquakes that happen at active fault lines.
Professor Yu Inchang (Kyungpook National University) said, “I can tell you that the independent granite bodies which are located deep underground might reoccur in the future. There needs to be more research and analysis conducted to learn more about the unique nature of earthquakes in Korea.
The specialists said that these underground structures are relatively less stable so they could cause more earthquakes; therefore, we should learn more about the geological features in order to develop prevention measures for future earthquakes.