Geological Agency: Mitigation of the real threat of the Lembang Fault cannot be delayed

The area located near the fault line is potentially at risk of experiencing very strong tremors. Non-engineered buildings will certainly be very vulnerable.

Bandung (ANTARA) - The Geological Agency of the Ministry of Energy and Mineral Resources (ESDM) has affirmed that the potential threat of earthquakes from the activity of the Lembang Fault is a real risk that must be immediately anticipated seriously through sustainable mitigation efforts.

The Head of Earth Investigation at the Center for Volcanology and Geological Hazard Mitigation (PVMBG), Supartoyo, in Bandung, Thursday, said that the potential for earthquakes up to magnitude 6.8–7 could occur if all segments of the Lembang Fault, which is approximately 29 kilometers long, move.

“If all segments move, then the potential magnitude could reach 6.8 to 7. This is the basis in preparing the worst-case scenario for contingency plans (future risks),” he said.

According to him, this scenario can occur in the area around the fault, where the ground acceleration is estimated to be between 0.6 to 0.8 g and the intensity of the vibrations is estimated to exceed VIII MMI.

This condition has the potential to cause significant damage, especially to buildings that are not designed with earthquake-resistant standards.

“The area located near the fault line is potentially at risk of experiencing very strong tremors. Non-engineered buildings will certainly be very vulnerable,” he said.

He also explained that the magnitude of the impact of the earthquake is not only determined by the magnitude, but also by the proximity to the earthquake source, the depth of the hypocenter, local geological conditions, and the quality of building construction on the surface.

“Magnitude is not the only factor. Proximity to the earthquake source and soil conditions greatly affect the level of damage that occurs,” he said.

Based on data from the Geological Agency, the number of damaging earthquakes in Indonesia from 2000 to 2025 ranges from five to 41 events per year.

In 2026, until now, six damaging earthquake events have been recorded based on a compilation of data from various sources, including the National Disaster Management Agency (BNPB).

A number of major earthquake events in Indonesia also show significant economic impacts, such as the 2006 Yogyakarta earthquake causing losses of around IDR 29.2 trillion, the 2004 Aceh earthquake and tsunami around IDR 13.4 trillion, the 2018 Palu earthquake around IDR 8.5 trillion, and the 2022 Cianjur earthquake around IDR 4 trillion.

Supartoyo assessed that these losses occurred due to disasters in a very short time, even less than 15 minutes, but had a long-term impact on social life and regional development.

“The losses can be equivalent to the regional development budget for one year. Therefore, mitigation must be seen as an investment, not a burden,” he said.

He emphasized that mitigation must be carried out in accordance with Law Number 24 of 2007 concerning Disaster Management through structural and non-structural approaches.

Structural mitigation includes the construction and strengthening of earthquake-resistant buildings, while non-structural mitigation includes socialization, simulations, training, and the preparation of regulations.

“Earthquakes cannot be prevented, but the risks can be reduced if preparedness and construction standards are consistently applied,” he said.

With the potential for activity of the Lembang Fault which is located near densely populated areas in the Greater Bandung area, he believes that mitigation efforts can no longer be delayed so that the impact on casualties and economic losses can be minimized.