PUBLISHED ONAugust 24, 2025 5:29 AMUPDATEDAugust 25, 2025 5:40 PMBYSean LerA 4.1-magnitude earthquake jolted Johor on Sunday morning (Aug 24).
In the hours after, social media was abuzz with discussions on how an earthquake can happen in Malaysia since the country is situated outside the Pacific Ring of Fire.
Some also asked if an earthquake will happen in Singapore.
In an interview with Malaysian media outlet The Star in March, Institute of Geology Malaysia president Abd Rasid Jaapar highlighted that while Malaysia is not situated along the collision zone of major tectonic plates, several minor tremors have been recorded in certain areas over recent years.
Jaapar added that while there is presently no significant earthquake risk in Malaysia, the risks exist, citing the seismic activities in Bukit Tinggi.
“Earthquakes are unpredictable in both location and magnitude.
“If we claim there is no risk at all, that would be inaccurate. Natural events like earthquakes are unpredictable, so we must remain cautious, but there is no need for undue concern,” Jaapar told The Star.
A series of 13 minor earthquakes — ranging from 2.5 to 3.5 magnitude — occurred along Malaysia's Bukit Tinggi fault, spanning the Selangor and Pahang border from Nov 30, 2007 to Jan 14, 2008.
In a written reply to a parliamentary question posed by retired Member of Parliament Dr Lim Wee Kiak in 2015, then-Environment and Water Resources Minister Dr Vivian Balakrishnan said that the likelihood of an earthquake occurring in Singapore is "extremely low".
"Most earthquakes tend to occur at the active margins of tectonic plates, such as in Sumatra, Java, the Philippines, Japan and South America.
"Singapore is situated about 400km from the nearest plate margin. The crust underlying Singapore is considered stable by experts in geology, and the records from our seismic stations and global positioning instruments show no evidence of active faults within Singapore," said Dr Balakrishnan.
On the frequently asked questions section of its website, the Earth Observatory of Singapore (EOS) echoed this, but cautioned that big earthquakes occurring on the nearest plate boundary — the Sunda Megathrust, offshore Sumatra — may affect Singapore.
"An earthquake powerful enough could swing the buildings located over reclaimed land or sediments," said EOS.
In a 2023 update posted on its website, Singapore's Building and Construction Authority said that buildings in Singapore are designed to be sufficiently robust to withstand tremors caused by distant earthquakes.
This is enshrined in the Singapore Standards — Design of Structures for Earthquake Resistance — which follow European standards.
On Feb 25, 2022, Singapore experienced tremors when a 6.0-magnitude earthquake struck the western coast of Sumatra.
Writing for The Straits Times in 2022, senior research fellow at the Nanyang Technological University, Dr Karen Lythogoe, said that more research is needed to assess the activity of geological faults and seismic hazard in Singapore and the neighbouring regions.
AsiaOne spoke to Associate Professor Wei Shengji from the Active Tectonics and Earthquakes department at the Nanyang Technological University's Asian School of the Environment to understand if Singaporeans should be concerned.
Using seismic data recorded in Singapore between 2006 and 2022, Assoc Prof Wei said that his team had detected over 200 micro-seismic events compared to what was availble in the regional and global earthquake catalogue, adding that most of them took place tens of kilometres away from Singapore.
He added that even with the current dataset, it is not always clear which fault hosted each of the seismic events.
"Based on the highly scattered distribution of past seismic events, which are far from the 4.1-magnitude earthquake in Segamat, Johor, it seems more reasonable that a different fault that those which hosted other events may have ruptured on Sunday," said Assoc Prof Wei, adding that there may be more active faults than experts are aware of.
This was echoed by Dr Mohd Zamri Ramli, who is part of the University Teknologi Malaysia's engineering seismology and earthquake engineering research team.
Dr Ramli told Malaysian media outlet The Star that past geological data showed no evidence of active faults in Segamat except for some activity recorded in Mersing, along the Mersing fault line.
"However, the 4.1-magnitude tremor at 6.13am on Aug 24, followed by a 2.8-magnitude aftershock four hours later in Yong Peng, suggests the presence of a fault that requires further detailed study," added Dr Ramli.
Both Assoc Prof Wei and Dr Ramli separately concurred that further detailed studies are required to understand if the Segamat event may be due to a small inactive fault that may have been reactivated, or a different fault.
Assoc Prof was however careful to assure that the level of activity of such faults is "dramatically lower than those plate boundary faults".
He also emphasised that the tremors felt in Singapore, such as in 2022, would happen when the magnitude of the seismic event is over six and at interpolate areas such as the Sumatran subduction zone in Indonesia.
"Key scientific data should be collected, and more research conducted to better understand and quantify the level of seismic risk.
"This is a continuous and join effort between engineers, scientists and policy makers to build a safer Singapore," said Assoc Prof Wei.
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