Palu Koro Fault Zone Microzonation and Its Relation to Potential Hazard

The Mw 7.4 earthquake on September 28, 2018 in Palu-Donggala has resulted in significant fatalities and damages due to liquefaction and ground oscillation. Small-scale subsurface geological features on the zone are presumed to be a controlling factor for liquefaction. Therefore, we ran 130 microtremor measurements around the southern Palu region to study the microzonation related to hazard-prone areas, especially for liquefaction and collapsed construction. A series of single-station surveys were conducted to delineate the region's predominant period, amplification factor, and seismic vulnerability distribution. The resulting microzonation maps were cross-validated with geological maps, liquefaction zone, and collapsed building distribution. The study suggested several hazard-prone areas that should be paid attention to, especially for construction planning.