In early September 2026, a video on YouTube spread rapidly among residents of Greater Jakarta and Banten. Frankie MacDonald, a Canadian content creator who describes himself as an amateur weather observer, claimed that a magnitude 7.0 to 9.0 earthquake would hit Java and Jakarta before the end of 2026.
The claim caused widespread concern, prompting Indonesia’s Meteorology, Climatology, and Geophysical Agency (BMKG) to issue a public clarification. In a statement to CNBC Indonesia, quoted on September 8, 2026, BMKG’s Director of Earthquake and Tsunami, Wijayanto, stressed: “Earthquakes cannot yet be predicted as to exactly when and where they will occur.”
But if earthquakes cannot be predicted with certainty, what can science actually tell us about when one might occur?
A Zone That Has Been Quiet for 269 Years
The key term here is seismic gap.
In a separate statement to CNBC Indonesia on the same day, September 8, 2026, Daryono, a former Director of Earthquake and Tsunami at BMKG and now a member of the Indonesian Disaster Experts Association (IABI), explained that a seismic gap is an “active earthquake source zone that has not experienced a major earthquake for decades to hundreds of years.”
The Sunda Strait Megathrust Zone, which stretches south of Banten, has not recorded a major earthquake since 1757. As of 2026, that means 269 years without a significant release of energy.
Based on BMKG modeling, if the zone were to rupture all at once, its potential magnitude could reach 8.7 to 8.9. For comparison, the Mentawai-Siberut zone off the coast of Sumatra has experienced a similar gap since 1797, or 229 years without a major earthquake.
These figures may sound like a countdown. But geological experts, including former BMKG head Dwikorita Karnawati and independent geologist Awang Satyana, have repeatedly stressed that the magnitude 8.9 figure represents a worst-case scenario.
The scenario is used for building safety standards and mitigation infrastructure, as outlined in the 2024 Indonesian Earthquake Source and Hazard Map. It is not a prediction that an earthquake of that size will definitely occur, let alone in the near future.
In other words, a seismic gap is a long-term assessment of potential based on the history of earthquakes. It is not a countdown to a specific date.
Why “Quiet for a Long Time” Does Not Mean “About to Explode”
This is where one of the most common misunderstandings arises: the assumption that the longer an earthquake zone remains quiet, the closer it is to producing an earthquake. Scientifically, the relationship is not that simple.
A study published in the journal Scientific Reports in 2020 mapped similar seismic gaps along the southern coast of Java. The researchers used the relocation of thousands of small earthquakes and GPS data to measure slip deficit, the difference between the movement expected from tectonic plates and what is actually recorded at the surface.
However, the study explicitly noted that the presence of a seismic gap does not automatically mean elastic energy is building up to be released all at once. Some of that energy could instead be released gradually through slow slip, a movement of tectonic plates that produces little detectable earthquake activity.
This makes it difficult to detect using surface seismic data alone. Estimates of megathrust earthquake recurrence intervals are also not fixed numbers.
Another study cited in that research, based on analyses of ancient tsunami deposits along Java’s southern coast, estimated that major megathrust earthquakes in the region recur at intervals of roughly 500 years.
That is an extremely long timeframe with substantial uncertainty. It is far from the daily, monthly, or even yearly precision required for something to qualify as a “prediction.”
The Gold Standard No Scientist Has Yet Met
The United States Geological Survey (USGS), the official geological survey of the U.S. government and a global reference for earthquake science, has a strict definition of what qualifies as a valid earthquake prediction.
It must include three elements at once: the date and time, the location, and the magnitude, all with practically useful precision.
According to the USGS, no scientist or institution anywhere in the world, including the USGS itself, has so far succeeded in meeting all three criteria to predict a major earthquake before it occurs.
The USGS also emphasizes that those who claim to predict earthquakes generally fail to meet at least one of the three criteria. Others make predictions so broad that an earthquake will almost certainly occur somewhere, at some point, that appears to match the claim.
What science can do today is not prediction, but long-term probability estimates and early warnings. Earthquake early warning systems operate within seconds after an earthquake begins, not before it happens.
That is why BMKG, the USGS, and the global seismological community agree that claims like Frankie MacDonald’s video, which gives a specific date and region without verifiable scientific evidence, have no scientific basis, no matter how plausible the magnitude figures may sound.
The Sunda Strait does have a real seismic gap that has been studied for decades. What does not exist, and may never exist, is a precise calendar telling us when that gap will be filled.
