Malaysia’s state of Johor experienced a 3.2-magnitude earthquake in Segamat today (27th), marking the third earthquake to hit the state within a week. Authorities have attributed this event to the reactivation of an ancient fault line.
The Malaysian Meteorological Department (MetMalaysia) confirmed that the earthquake occurred at 8:59 a.m. with its epicenter located at approximately 2.33 degrees north latitude and 102.79 degrees east longitude, about 18 kilometers south of Segamat in Johor. The quake had a depth of 10 kilometers and was felt in various parts of Johor and southern Pahang.
Local media reported that residents in Segamat heard a loud noise and felt their doors and windows shaking for several seconds.
This incident marks the third earthquake to hit Johor within a week.
On August 24th at 7:25 a.m., the Meteorological Department confirmed that an earthquake occurred at 6:13 a.m. around 5 kilometers west of Segamat, with a shallow depth of about 10 kilometers.
Local netizens took to social media to share their experiences of being awakened from sleep by the earthquake. Surveillance footage from a house showed vehicles in the yard shaking intensely, triggering burglar alarms. Videos also depicted startled birds in a homeowner’s enclosure chirping frantically and varying degrees of damage to structures.
On the same day, at noon, the Meteorological Department once again confirmed on Facebook that a 2.8-magnitude earthquake occurred at approximately 28 kilometers northwest of Labis at 9 a.m., with a depth of 10 kilometers. The two earthquake locations were around 120 kilometers apart.
The earthquake on the 24th was also felt in Mersing, Labis, Batu Pahat, and surrounding areas at moderate intensity, fortunately resulting in no casualties.
Reports from various media outlets such as Bernama, Selangor Times, Reddot, and 8TV News indicate that officials attribute the earthquake in Segamat on the 24th to activity along the sinistral strike-slip fault.
Citing a statement from the Malaysian Geological and Mineral Sciences Department (JMG) on the 25th, Bernama reported that the epicenter of the Segamat earthquake was near the Mersing Fault Zone, which runs in a west-northwest to east-southeast direction. The earthquake involved a movement of the crustal block to the west on the northern side of the fault and to the east on the southern side.
The JMG explained that the event signifies the reactivation of an ancient fault, releasing accumulated tectonic energy within the continental crust. With a focal depth of only 10 kilometers, the earthquake was determined to be caused by continental crustal movements, not volcanic activity or deep-sea subduction.
The JMG emphasized that Malaysia sits atop the relatively stable Sunda Plate but is influenced by regional tectonic stress, having experienced slight tremors in 2021 and 2023, although not in Johor. Previous records indicate that Johor had two on-land earthquakes in 1922, on January 31st (magnitude 5.4) and February 7th (magnitude 5.0), but the exact locations were unspecified.
The earthquake in Segamat adds to the historical record of reactivated ancient faults on the Malay Peninsula. Previous seismic events include those in Pahang’s Bukit Tinggi (2007-2010), Kenyir Lake in Terengganu (1984), Kuala Pilah in Negeri Sembilan (1987), and Manjung-Tambun-Temenggor in Perak (1990).
Officials noted that the Malay Peninsula is not a major seismic zone, but the risk of small to moderate earthquakes persists.
Seismologist Mohamad Zaini, in an interview with Oriental Daily, predicted that the earthquakes in Segamat and Labis suggest unrecognized active fault activity in Johor.
Professor Azlan Adnan, head of the earthquake research group at Malaysia’s Polytechnic University, mentioned that new buildings constructed post-2017 generally adhere to earthquake-resistant designs. However, older buildings built before 2017 largely lack such features. Coupled with a general lack of earthquake evacuation awareness among the populace, the potential consequences of a strong earthquake or tsunami could be unimaginable.