BMKG Records 17 Aftershocks After M4.7 Tremor in Indonesia's West Sumatra
Reporter
December 29, 2025 | 12:32 pm
TEMPO.CO, Jakarta - The Meteorology, Climatology, and Geophysics Agency (BMKG) has recorded a total of 17 aftershocks in Agam, West Sumatra, since the M4.7 earthquake struck last Sunday. The earthquake's epicenter was located in the Kajai Talamu Segment of the Sumatra Fault, which stretches towards Sianok.
"We have recorded 17 aftershocks until this morning," said Suaidi Ahadi, the Head of the BMKG Geophysics Station in Padang Panjang, when contacted by Tempo on Monday morning, December 29, 2025.
The two main earthquakes were felt by residents. The first earthquake with a magnitude of 4.6—previously reported as M4.7—occurred at 09:11 a.m. local time, centered 18 kilometers northeast of Agam.
Four minutes later, at exactly 09:15 AM, a second tremor with a magnitude of M4.7 struck the region.
Both epicenters had the same depth, which was 10 kilometers. "We can also call it twin earthquakes, but in the same segment," explained Suaidi.
Based on BMKG's shakemap, the earthquakes were felt in Agam, Pasaman, West Pasaman, and Bukittinggi with a III to IV MMI (Modified Mercalli Intensity) scale. The shakings were felt indoors, akin to trucks passing by, rattling windows and doors. Meanwhile, in Padang Panjang and Payakumbuh, the tremors were felt in a lower II-III MMI scale.
Suaidi explained that these earthquakes were shallow tectonic tremors triggered by the activities of the Kajai-Talamau Segment, which is part of the Sumatra Fault. "Yes, the Kajai-Talamau Segment, which is the source of this earthquake, is on the same line as the major earthquakes that occurred in Bonjol and Talamau a few years ago," he said.
He also reported that as a result of these consecutive earthquakes, minor damage was reported in several buildings in the Agam Regency. Cracked walls were reported on four houses in the area.
He urged residents of Agam and its surrounding areas to remain vigilant against potential aftershocks and to pay attention to the hilly conditions, considering that the high rainfall levels can trigger post-earthquake landslides.
Read: Earthquake Hits Gayo Lues, Tremors Felt Across Flood-Hit Aceh Tamiang
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