Megathrust Threats in Several Regions of Indonesia That Must Be Watched Out For
Author: Jacob Ereste
Freelance Journalist
The Head of the BMKG Earthquake and Tsunami Center, Daryono, has issued a warning regarding the threat of a Megathrust earthquake for Indonesia from two Megathrust zones just waiting for the right time. This means that a serious earthquake and tsunami will soon occur in Indonesia, as widely reported by CNBC Indonesia on June 7, 2025.
This is because Indonesia’s geographical location is on the Pacific Ring of Fire which brings together several plates, so that the threat of a Megathrust earthquake can arise from 13 segments spread across Indonesia.
Each of the Megathrusts is in the Sunda Strait and Mentawai-Siberut. From BMKG’s records, the two zones have not experienced an earthquake or seismic gap for centuries. Because in its habit, a large earthquake has its own cycle spanning hundreds of years.
Meanwhile, the National Research and Innovation Agency (BRAIN) said that it is necessary to be aware of the impact of the Megathrust in the southern region of West Java which extends to the Sunda Strait. Other researchers also warned that the energy locked in the subduction zone will continue to increase over time. Therefore, if this energy is released at once, the impact will cause a large earthquake of up to a magnitude of 8.7 which is very destructive to nature and human victims.
The BRIN Geological Disaster Research Center reported that the release of this earth’s energy not only triggers strong shocks, but also moves the sea water column which will cause a large tsunami. In terms of calculations, if the Megathrust occurs in the Pangandaran area, a 20-meter tsunami wave could spread to Banten and Lampung and even Jakarta. So, all of the Banten coast will be affected, only the height of the tsunami – the sea water – can be different, said Nuraini Rahma Hanifa from BRIN, as conveyed to CNBC Indonesia.
On the Banten coast, the tsunami is estimated to reach a height of 4 meters to 8 meters. This means that the sea water that spills onto land can reach Tangerang. Meanwhile, on the coast of Lampung, he said that all areas facing the Sunda Strait would be affected by the tsunami. Just imagine, if in Jakarta the sea water could soar as high as 1.8 meters. Although the arrival of water due to the tsunami was slower than in other areas. However, within 2.5 hours since the earthquake occurred, the overflow of water due to the tsunami had also inundated Jakarta.
From the calculations of experts in the South Java region, the tsunami will hit in just 40 minutes since the incident occurred. Meanwhile, in Lebak, Banten, in just 18 minutes the sea water has spread throughout the Lebak area. Only in the North Jakarta area will the overflow of sea water due to the tsunami hit after 2.5 hours.
Therefore, BRIN invites all Indonesian citizens to always be aware of the risk of megathrust, because the consequences are not only earthquakes and tsunamis that occur with the overflow of sea water that rises to land, but also damage to infrastructure – collapsed buildings and fallen trees to the loss of communication contacts to the paralyzed social and economic order – could increase the number of victims who are more important to save.
Even so, BMKG itself has not been able to confirm when this major disaster will occur. Head of BMKG, Dwikorita Karnawati admitted that her party continues to discuss the threat from nature so that the public is always ready to face the effects of the megathrust that will occur in Indonesia which is expected to occur in the near future.
BMKG itself has carried out mitigation and education, readiness, preparedness as part of the disaster anticipation steps due to megathrust. Starting from the placement of tsunami early warning system sensors. And Ins Tews was deliberately installed facing the direction of the megathrust. Of the 13 megathrust segments that threaten Indonesia starting from the Mentawai, Enggano, Sunda Strait, West Java, Central Java, East Java, Sumbangan, Aceh-Andaman, Nias-Simrlue regions to the North Sulawesi and Papua megathrusts.
Banten, June 10, 2025
—
