KUALA LUMPUR: The 4.1 magnitude earthquake that struck Segamat should be taken as a “wake-up call” for Malaysia to strengthen seismic monitoring, disaster preparedness and structural safety audits, say structural and seismic experts.
Malaysian Academy of Sciences fellow and Malaysian Structural Steel Association (MSSA) deputy president Dr Azlan Adnan said the 6.13am tremor was likely triggered by tectonic stress release on a minor fault previously unmapped or thought inactive in southern Peninsular Malaysia.
“Johor, including Segamat, was previously considered outside active zones like Sabah or Sumatra, but the risk is not zero. From an engineering seismology perspective, this is an early signal that local geological structures must be identified, characterised and closely monitored.
“This requires detailed fault-mapping studies, effective site-effect assessments and a denser monitoring network in the region,” he said.
Azlan said records from MetMalaysia showed the peak ground acceleration intensity reached 10%, a level that could potentially cause minor damage to nearby structures if repeated.
Commenting on aftershock risks, he said the first 72 hours after a tremor were the most critical.
“Smaller aftershocks are possible. The likelihood of a stronger quake remains low, but not impossible. Caution should be exercised as though this were a foreshock until subsequent activity subsides and no dangerous clustering is detected.
“If it is indeed a foreshock, then a stronger earthquake of greater magnitude than 4.1 could occur,” he warned.
In terms of impact, he said that older or poorly-maintained structures, non-structural components such as suspended ceilings, decorative stonework and rooftop water tanks, as well as slopes and retaining walls, were at risk of light to moderate damage if tremors recur.
“Water, electricity and telecommunications may also be disrupted if equipment used is not quake-resistant. We should not wait for major damage before strengthening preparedness,” he said, Bernama reported.
Azlan urged the government, technical agencies, local authorities and researchers to work together in strengthening high-density seismometer networks, applying Global Navigation Satellite System and Interferometric Synthetic Aperture Radar technologies, conducting urban microzonation studies and carrying out rapid audits of critical buildings.
He also advised the public to practise international safety guidelines such as “Drop, Cover, Hold On” during tremors, exit calmly once shaking stops, avoid using lifts, check for structural damage and keep a 72-hour emergency kit with water, food, flashlights, medicines and a family communication plan.
