Research

Active Fault & Earthquake Hazard Assessment

Forces responsible for tectonic plate motions are accommodated by active faults.

The stored energy on active faults are released mostly by earthquakes.

I am trying to understand the history of paleo-earthquakes in a given active fault system, and its implications for earthquake hazard assessment.

Mapping Faults

· Large paleo-earthquakes resulted in ruptures on the Earth's surface, and this provides an opportunity to map the active faults.

· High-resolution fault mapping is an essential part for active fault study and seismic hazard assessment.

The HRS imagery mapping for the 1905 Bulnay earthquake surface rupture [Choi et al., 2018].

Fault Zone Architectures

· Internal structures of the faults are a result of repeated earthquakes, and they are able to affect to slip behaviors of the next earthquake.

· By studying fault zone architecture, it is possible to explore the evolutional history of the fault and to examine the characteristics of future earthquakes.

A cross-sectional fault zone model of the Yangsan Fault in Korea [Choi et al., 2009].

Continental Strike-Slip Earthquakes

· Continental strike-slip earthquakes are prone to major sources for seismic hazard.

· Fault geometry and slip variations along strike-slip earthquake surface ruptures are one of the most useful tools to study earthquake rupture processes.

· Fault segmentation plays a key role in understanding the history of earthquake ruptures both during individual events and over multiple events.

Geometry, slip distribution, and segmentation of the 1957 Gobi-Altay earthquake surface rupture [Choi et al., 2012]

Korean Active Tectonics

· Historical earthquakes in Korea have caused considerable damages, and yet I think we still have a poor map of active faults in the region.

· Korean active faults should be identified and studied in more detail based on high-resolution fault mapping and paleoseismology.

Segmentation of the Yangsan Fault in SE Korea [Choi et al., 2017].