Magnitude 3.2 Segamat Quake Linked To Mersing Fault Reactivation - JMG

PUTRAJAYA, Aug 28 (Bernama) -- The magnitude 3.2 tremor that struck Segamat, Johor yesterday was caused by the reactivation of the Mersing Fault due to regional tectonic stress, according to the Department of Minerals and Geoscience Malaysia (JMG).

In a statement today, JMG said Malaysia lies on the relatively stable Sunda Plate but remains influenced by regional forces, particularly from the Sunda subduction zone off western Sumatra.

These pressures can reactivate existing faults in Peninsular Malaysia, triggering small to moderate earthquakes.

“Preliminary mapping placed the Segamat epicentre near the extension of the Mersing Fault, which trends west-northwest to east-southeast.

“Seismological analysis indicated a left-lateral strike-slip movement, with the northern block shifting west and the southern block moving east.” the statement read.

JMG said the shallow depth of about 10 km confirmed the tremor was caused by continental crust movement, not volcanic activity or deep-sea subduction.

Peninsular Malaysia has previously recorded tremors in Bukit Tinggi (Pahang), Kenyir (Terengganu), Kuala Pilah (Negeri Sembilan) and Manjung–Temenggor (Perak). Johor also experienced minor quakes in 2021 and 2023 linked to seismic activity off Sumatra.

“These incidents, including the Segamat quake, show that the continental plate beneath Peninsular Malaysia still stores tectonic stress that may be released periodically,” the statement said.

As such, JMG stressed the need for continuous monitoring, updated fault mapping and early warning systems to improve preparedness and protect infrastructure.

Together with MetMalaysia under the Ministry of Natural Resources and Environmental Sustainability (NRES), the department will step up monitoring and scientific analysis in at-risk areas, whether from local or regional seismic activity.

-- BERNAMA