The earthquake hazard level of Makassar

An earthquake is a natural disaster that is often found in Indonesia because its geological area is a meeting between three large tectonic plates. Earthquakes have a high level of danger due to unpredictable events. In the Sulawesi region, especially Makassar, in 2017, there was an earthquake measuring 3 SR-6 SR, with a shallow epicenter. Epicenter distance calculation is used to determine the value of peak ground acceleration (PGA), which can then affect the intensity value in the hypocenter. This study aims to analyze the level of earthquake hazard using the PGA value as the basis for the initial reference of earthquake disaster mitigation. Variables used include rock type (geology), slope and the value of peak ground acceleration (PGA). Data on rock types were obtained from the Makassar City BPBD, and slope variables were processed from the SRTM DEM. Next, an overlay analysis was conducted to determine the level of earthquake hazard using a GIS application. The results showed that Makassar City had a majority of 94% of its area has a low level of earthquake hazard, while 6% of the area that had an earthquake hazard level was quite high in the east of Makassar. The frequency of earthquakes that were felt to be influential by the community (scale III MMI) was only two times in the last three decades (1996 and 2018).