SIMALUNGUN | INDATANEWS.COM - A tectonic earthquake measuring magnitude 6.4 struck the Simalungun region of North Sumatra on Saturday, August 15, 2026, at 5:54:52 p.m. Western Indonesia Time (WIB). The Meteorology, Climatology and Geophysics Agency (BMKG) said the earthquake occurred on land and posed no tsunami threat.
According to the
BMKG's latest analysis, the earthquake had a magnitude of M6.4 and occurred at a depth of 168 kilometers. The epicenter was located at 2.91° north latitude and 98.93° east longitude, approximately 11 kilometers southeast of
Simalungun, North Sumatra.
Dr. Wijayanto, S.T., M.Sc., Director of the Earthquake and Tsunami Division at the BMKG headquarters, said the location of the epicenter and the depth of the hypocenter indicated that the earthquake was a moderate-depth earthquake associated with tectonic plate subduction.
"Considering the location of the epicenter and the depth of the hypocenter, this was a moderate-depth earthquake caused by tectonic plate subduction," Wijayanto said on Saturday, August 15, 2026.
The BMKG also confirmed through post-earthquake modeling that there was no tsunami threat. Therefore, residents in the affected areas do not need to be concerned about a tsunami resulting from the earthquake.
Earthquake Epicenter Located on Land
In addition to analyzing the location and depth of the earthquake, the BMKG also examined the mechanism of the earthquake source. The results indicated a combined strike-slip and downward movement mechanism, known as an oblique normal fault.
Wijayanto explained that the characteristics of the earthquake were consistent with the location of the epicenter and the depth of the hypocenter. At a depth of 168 kilometers, the earthquake was classified as a moderate-depth earthquake.
The tremors were felt in several areas of North Sumatra with varying intensities. Based on estimates from the ground-shaking map, known as the Shakemap, the BMKG recorded intensity levels of V MMI in several areas.
Tremors at intensity V MMI, at which almost everyone feels the movement and many people are awakened from sleep, were recorded in Tebingtinggi, Kabanjahe and Limapuluh.
In several other areas, tremors were felt at intensity IV MMI. At this level, shaking can be felt by many people indoors during the daytime.
Areas recording intensity IV MMI included Raya in
Simalungun, Panombeian Pane in
Simalungun, Panei in
Simalungun, Pematangsiantar and Pangururan.
The different intensity levels show that the strength of the shaking perceived by residents can vary from one location to another. Both the distance from the epicenter and local geological and building conditions can influence the intensity of the shaking experienced by the population.
MODERATE-DEPTH EARTHQUAKE:
BMKG Earthquake and Tsunami Division Director Dr. Wijayanto explains that the
magnitude 6.4 earthquake in
Simalungun was a moderate-depth earthquake caused by tectonic plate subduction. (PHOTO: Doc.
BMKG)
BMKG Reports No Aftershocks So Far
The
BMKG continues to monitor seismic activity following the main earthquake. As of 6:16 p.m. WIB,
BMKG monitoring results showed no indication of further earthquakes or aftershocks.
Wijayanto said the BMKG would continue monitoring earthquake activity and provide the latest information to relevant authorities and the public.
"The
BMKG will continue to monitor the activity of possible aftershocks and inform the relevant authorities and the public of the latest findings," Wijayanto said.
The monitoring is important to ensure that the public receives information based on official BMKG observations and analyses. Residents are also urged to follow information only through official BMKG channels and not to immediately believe unverified reports.
PUBLIC URGED TO AVOID DAMAGED BUILDINGS: The
BMKG urges residents to remain calm, avoid unverifiable rumors and stay away from buildings that have developed cracks or other damage following the earthquake. (PHOTO: Doc.
BMKG)
BMKG Urges Public to Remain Calm
The
BMKG urged residents to remain calm following the earthquake in
Simalungun. At the same time, people were advised to avoid information or rumors from unreliable sources whose accuracy could not be verified.
The agency also called on residents to stay away from buildings that have developed cracks or other damage as a result of the tremors. This measure is important to prevent risks if the structural stability of a building can no longer be guaranteed.
People in the affected areas should also remain aware of their surroundings and ensure that their homes and other buildings they use are in a safe condition. If damage is found in a building, residents should not enter it until its safety has been assessed.
In view of the modeling results indicating that the earthquake posed no tsunami threat, and the absence of aftershocks as of 6:16 p.m. WIB, the BMKG continued to urge residents to follow official information and not to panic. The BMKG will update its information in accordance with the results of further monitoring in the field. (IDNC)
REPORTER:
Ahmad Zulfikar | EDITOR:
Fik Sagala