The seismic activity following the massive M7.6 earthquake that struck North Maluku on April 2, 2026, is showing a significant downward trend, according to the latest data from the Meteorology, Climatology, and Geophysics Agency (BMKG). Experts predict that the frequency of aftershocks will gradually diminish and completely subside within two to three weeks from the date of the initial quake.
This projection is based on statistical analysis of the tectonic sequence. While the overall number of events is dropping, officials warn that the period of decay is often unpredictable. Residents may still experience occasional tremors as the earth stabilizes, meaning the risk of localized shaking remains present despite the overall decline in activity.
As of 6:00 AM WIB on April 9, 2026, BMKG has recorded a total of 1,378 aftershocks. Of these, 25 were strong enough to be felt by local populations. The data reveals a consistent decline in daily occurrences, dropping from a peak of 394 events on the first day to 91 on the sixth day, and further down to 63 by the seventh day.
Analyzing the Seismic Decay and Local Impact
Nelly Florida Riama, the Deputy for Geophysics at BMKG, emphasized that while the trend is positive, the intensity of these aftershocks remains fluctuant. “Meskipun tren menunjukkan penurunan, intensitas gempa selama masa peluruhan ini bersifat fluktuatif, sehingga getaran yang dirasakan sesekali mungkin masih muncul sebelum kondisi benar-benar stabil,” Riama stated in Jakarta on Thursday.
To understand the precise impact of the M7.6 event, a joint survey team—comprising experts from the central office, the Region IV Meteorological, Climatology, and Geophysics Agency, and Technical Implementation Units (UPT) from North Maluku and North Sulawesi—has been conducting macroseismic surveys in the field. These efforts are designed to validate the actual shaking experienced by residents against the agency’s digital shake-maps.
The findings have confirmed that the most intense shaking reached a scale of VII MMI in the Pulau Batang Dua district. This level of intensity typically involves significant damage to poorly constructed buildings and can cause noticeable distress to residents.
Tsunami Verification and Coastal Effects
Beyond the shaking, BMKG officials have been verifying the reach of the tsunami that followed the main shock. Field officers confirmed inundation marks ranging from 0.5 to 1.5 meters in several key coastal areas, including Bitung, Pulau Lembeh, and the North and Southeast Minahasa regions.
The presence of these water marks serves as a critical verification of the agency’s “Siaga” (Alert) level Tsunami Early Warning, which was issued immediately following the event. By correlating the physical evidence of water penetration with the warning timing, the agency is assessing the effectiveness of its early warning systems in the region.
| Timeline | Number of Aftershocks | Trend Status |
|---|---|---|
| Day 1 (April 2) | 394 | Peak Activity |
| Day 6 | 91 | Significant Decrease |
| Day 7 | 63 | Continuing Decline |
| Cumulative (to April 9) | 1,378 | Decay Phase |
Mitigating Long-Term Risks: Liquefaction and Landslides
The recovery process is not merely about monitoring tremors. BMKG is currently implementing microzonation measurements to map soil vulnerability. This scientific process is essential for identifying areas prone to liquefaction—where soil behaves like a liquid during shaking—and potential landslides, both of which can be triggered by aftershocks even if the main quake has passed.
Parallel to these technical measurements, the agency has launched a massive socialization campaign. This effort is aimed at countering misinformation and hoaxes that often proliferate during natural disasters, which can lead to unnecessary panic and hinder official rescue and recovery operations.
According to Riama, the priority for teams on the ground is the education of the public regarding correct independent evacuation procedures. Ensuring that residents understand how to move to safety without waiting for official instructions in the first few seconds of a quake is seen as the most effective way to reduce casualties.
Safety Guidelines for Residents
Rahmat Triyono, the Acting Director of Earthquakes and Tsunamis at BMKG, has issued a specific advisory for those remaining in affected zones. He urges the public to remain vigilant but avoid panic. The primary concern now is the structural integrity of buildings that were damaged during the M7.6 event.
Residents are strongly advised to avoid entering or staying in buildings that exhibit significant structural cracks or visible damage, as aftershocks could trigger a total collapse of compromised structures. Those living near hilly terrain are warned to stay away from slopes, as the soil has been destabilized by the initial quake, making them highly susceptible to landslides.
To ensure the public receives accurate, real-time data, the agency requests that citizens rely exclusively on official channels. This includes the official BMKG website, the InfoBMKG mobile application, and the verified social media handle @infoBMKG.
The agency will maintain strict surveillance of tectonic activity in North Maluku. Monitoring will continue until all seismic parameters return to their baseline normal levels, ensuring that the transition from the emergency phase to the recovery phase is based on verified geological stability.
We invite you to share this update with those in the affected regions to help spread verified safety information. For further developments, stay tuned to our continuing coverage of the North Maluku recovery efforts.
