Jeong-Sik Oh hikes to find hidden fault lines, with the help of drones, aircraft and laser technologies

I work to protect South Korea’s people against earthquakes

“In this photo, I’m examining a previously hidden active fault line between two geological blocks. I discovered it with other researchers working for the Korea Active Fault Research Group (KAFRG). The site is on a ridge in a forested valley about an hour’s drive from my office at Kyungpook National University in Daegu, South Korea. It’s part of the Hwalseongri fault, situated just south of Gyeongju National Park.

In 2016 and 2017, large earthquakes occurred in this area, causing great concern in our country. Until the Tōhoku earthquake in 2011 caused the nuclear disaster at Fukushima in nearby Japan, people in South Korea had not paid much attention to active faults. We’ve become more worried about seismic risks since then.

In 2017, South Korea’s government founded KAFRG to create the country’s first active-fault map. I’m one of around 60 scientists working as part of the group, which is based at Pukyong National University in Busan. My mission is to identify active faults that have the potential to cause earthquakes.

To do this, I collect evidence known as geomorphic markers. My tasks include analysing such linear features, together with fault-related landforms and the structural correlation of faults. Using the information I provide, geologists and geophysicists can conduct more detailed studies of these faults.

My fieldwork for KAFRG often uses drones to look for fault lines. However, for land covered by forest, lidar (laser imaging detection and ranging) technology is more important. Our research team uses aircraft to obtain lidar data for the areas we need to study. But because geomorphic markers are often hard to find, we also need to walk through forests and cross rivers. The best tool of all is my feet.”

Nature 636, 514 (2024)

doi: https://doi.org/10.1038/d41586-024-03997-9

This interview has been edited for length and clarity.

This story originally appeared on: Nature - Author:Dave Tacon