UNHAS Geophysics Guest Lecture: Discussing Local Site Effects and Earthquake Microzonation

Makassar – The Department of Geophysics, Faculty of Mathematics and Natural Sciences, Hasanuddin University, held a guest lecture titled “Local Site Effect and Earthquake Microzonation” on Friday, September 19, 2025. The virtual event via Zoom featured Ardian Yudhi Octantyo, S.Tr., M.DM., from the Directorate of Engineering Seismology, Potential Geophysics, and Time Signs of BMKG (the Indonesian Meteorology, Climatology, and Geophysics Agency) as the keynote speaker.

In his presentation, Ardian highlighted that Indonesia is among the world’s most seismically active regions, located along the Ring of Fire and at the convergence of three major tectonic plates: Indo-Australian, Pacific, and Eurasian. This unique geology makes the country highly vulnerable to earthquakes and tsunamis.

BMKG data shows a significant rise in earthquake occurrences. Between 1990 and 2008, the average was 2,254 earthquakes per year. However, from 2018 to 2023 the number rose sharply, exceeding 29,000 events in 2024. This increase is linked to both advances in detection systems and a natural trend of heightened tectonic activity.

The lecture focused on local site effects, which explain variations in ground shaking intensity depending on geological conditions. Ardian stressed the importance of earthquake microzonation maps, produced through geotechnical tests and seismic surveys, as essential references for spatial planning and infrastructure development.

He also addressed BMKG’s challenges in expanding accelerograph networks to Indonesia’s remote areas. He emphasized that increasing the number of instruments must go hand-in-hand with sustainable maintenance and monitoring systems to ensure optimal performance.

“Earthquakes are inevitable, but their impact can be reduced through scientific understanding, appropriate technology, and collective preparedness,” Ardian underlined.

Supported by SEG SC Unhas and HAGI SC Unhas as media partners, the guest lecture concluded with an engaging discussion, group photo session, and distribution of e-certificates. The event successfully fostered academic collaboration while enhancing awareness of earthquake hazard mitigation in Indonesia.

Group Photo of Participants in the Online Guest Lecture of Geophysics UNHAS on the Theme "Local Site Effects and Earthquake Microzonation"