BUTOLPOST – The Meteorology, Climatology and Geophysics Agency (BMKG) confirmed that the 7.7 magnitude tectonic earthquake that rocked the Sulawesi Sea on Monday (8/6/2026) and triggered a micro-scale tsunami did not originate from the megathrust zone as many people speculate.
BMKG Earthquake and Tsunami Director, Wijayanto, explained that the results of the National Earthquake Center’s analysis showed that the source of the earthquake was in the active subduction zone of the Philippine Sea Plate.
“Data from the National Earthquake Center shows that the Philippine Sea area is no longer included in the megathrust zone. This earthquake originated from the subduction zone,” said Wijayanto at a press conference in Jakarta, Monday.
According to BMKG, even though it did not originate from the megathrust zone, an earthquake of this magnitude was still capable of triggering deformation of the seabed which produced tsunami waves.
As of 08.20 WIB, a number of tsunami monitoring stations recorded a rise in sea level of between 9 and 75 centimeters in several areas. Among them were detected in Tanjung Sidupa Village, North Bolaang Mongondow Regency, North Sulawesi, and Talengen Village in the Sangihe Islands.
BMKG emphasized that the waves detected were still the first phase of a tsunami so monitoring continues to be carried out intensively.
“We will continue to monitor developments because what is currently recorded is still the first wave. If there are developments in other locations, we will immediately report them,” said Wijayanto.
Apart from triggering a tsunami, the main earthquake which occurred at 06.37 WIB was also followed by a series of aftershocks. As of 07.40 WIB, BMKG had recorded at least five aftershocks.
However, BMKG confirmed that the magnitude of the aftershocks showed a significant downward trend compared to the main earthquake, thus indicating a gradual release of energy in the area.
BMKG also reminded the public, especially those in the northern and eastern coastal areas of Indonesia, not to easily believe in unreliable information regarding the megathrust issue.
The public is asked to continue to follow official information and evacuation instructions from BMKG and the local government until the tsunami early warning status is completely lifted.
“We urge the public not to speculate on the megathrust issue which is not in accordance with scientific data. Continue to follow the official BMKG directions for mutual safety,” stressed Wijayanto.
Previously, a strong 7.7 magnitude earthquake centered in the Sulawesi Sea triggered an early tsunami warning for a number of areas in North Sulawesi, Gorontalo, Central Sulawesi, North Maluku and East Kalimantan.
