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Indonesia Braces for Potential Megathrust Earthquake and Tsunami: BRIN Urges Mitigation Measures
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Jakarta, CNBC Indonesia – Scientists from the Center for Geological Hazard Research at the National Research and Innovation Agency (BRIN), Nuraini Rahma Hanifa, are warning the public to be vigilant about potential disasters that could strike at any time. Rahma emphasized the risk of megathrust earthquakes in southern Java, which could generate tsunamis similar to the one experienced in Aceh.
The scientist stressed that this threat should be taken seriously by stakeholders and the public to mitigate the impact of potential disasters. Rahma’s research indicates that the megathrust segment in southern Java, including the Sunda Strait, has significant tectonic energy and the potential to cause earthquakes with magnitudes ranging from 8.7 to 9.1.
"If this megathrust occurs, it could trigger intense shaking and a tsunami that could reach Jakarta in approximately 2.5 hours," Rahma explained, according to a BRIN website statement on Friday (9/1/2025).
Simulations suggest that if a tsunami were to occur, wave heights could reach up to 20 meters along the southern coast of Java, 3-15 meters in the Sunda Strait, and around 1.8 meters along the northern coast of Jakarta. previous historical events like the 2006 Pangandaran tsunami, triggered by a marine landslide near Nusa Kambangan.
"The energy stored in the southern Java subduction zone continues to increase over time. If released suddenly, it could cause widespread damage from a high tsunami, not only in southern Java but also in other coastal areas," Rahma added.
[[[[Image Caption: Illustration of the Sunda Strait. (Dok. BMKG)]
BRIN emphasizes the importance of mitigation through structural and non-structural approaches. Structural measures include building tsunami barriers, wave breakers, and planning coastal areas with a safety buffer of at least 250 meters from the shoreline. Natural solutions like mangrove forests and other coastal vegetation can also help absorb tsunami energy.
Non-structural measures involve educating the public about disaster mitigation, conducting evacuation drills, and ensuring adequate evacuation routes and shelters.
"It’s crucial for communities to understand tsunami risks, have effective early warning systems, and be able to respond quickly," Rahma said.
In urban areas like Jakarta, where population density is high and soil is prone to amplifying shaking, mitigation efforts also include retrofitting or strengthening building structures.
"Retrofitting is crucial, especially for buildings in highly populated areas, as intense shaking could cause massive damage and loss of life," Rahma added.
For industrial areas like Cilegon, secondary hazards such as fires caused by fuel or chemical leaks in large factories also pose a threat and require strict safety standards.
Rahma noted that based on paleotsunami research, megathrust earthquakes in southern Java have a recurrence period of approximately 400-600 years. The last known event was in 1699, which means that the energy stored is now at a critical level.
"Disasters like the Aceh tsunami teach us that preparedness and disaster mitigation are key to saving lives," Rahma proclaimed.
To implement disaster preparedness, BRIN continues to collaborate with the Ministry of Maritime Affairs and Fisheries (KKP), the Indonesian Meteorological, Geophysical, and Climatological Agency (BMKG), and other related institutions to strengthen Tsunami Early Warning Systems, especially in the Sunda Strait and southern Java regions.
Rahma believes that the 20th anniversary of the Aceh tsunami serves as a momentum to raise awareness about similar potential disasters in the future, and with the support of research and technology, disasters can be managed more systematically and effectively.
With comprehensive mitigation efforts, Indonesia aims to minimize damage and losses from potential megathrust earthquakes and tsunamis in the future.
"We can’t predict when an earthquake will happen, but we can prepare. Adaptation, education, and collaboration are key to reducing disaster risks," Rahma concluded.
_source: CNBC Indonesia
