A welcoming sign as people enter the Segamat town. The district has been hit with several tremors since the first earthquake which occurred on Aug 24. — THOMAS YONG/The Star
SEGAMAT: The old township of Segamat, said to have been founded in the 16th century, has many government offices and heritage buildings, some dating back to the 1940s.
These structures are all vulnerable to tremors due to their age.
A detailed inspection is now needed to minimise the risk of damage in the event of an earthquake stronger than those that hit the district recently, said a Universiti Teknologi Malaysia (UTM) researcher.
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“Buildings on soft soil are more at risk compared to those built on hard rock. If a quake occurs, the shaking could be amplified, leading to greater damage,” said Faculty of Civil Engineering senior lecturer Dr Mohd Zamri Ramli yesterday.
Under the surface: A welcome sign as people drive into Segamat. (Inset) Mohd Zamri (centre) showing how an earthquake impacts a building during an earthquake disaster risk management programme. — THOMAS YONG/The Star
A comprehensive study is needed to assess the structural resilience of these older buildings, he said, particularly critical facilities such as hospitals, schools and government offices.
Mohd Zamri was commenting on the series of tremors that shook Segamat last month, including a 4.1 magnitude quake, followed by several smaller aftershocks.
He explained that the tremors were caused by tectonic plate adjustments from active fault lines in Sumatra and Java rather than the presence of active local faults in Peninsular Malaysia.
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“These were aftershocks. The pattern shows decreasing intensity and longer intervals between tremors, which is normal,” he said.
While the chances of a major quake in Johor are minimal, he cautioned that it could not be entirely ruled out.
“The last significant quake in Johor was in 1922, more than a century ago. For an inactive fault, recurrence can take 20, 30 or even 100 years but we cannot say it will never happen,” he said.
Mohd Zamri said Segamat’s relatively low skyline means high-rise buildings are not the main concern but medium and low-rise structures, particularly older ones, will bear the brunt of localised tremors.
“In past earthquakes in Taiwan and Japan, it was often the medium and low-rise buildings that collapsed, not the taller ones, because of how seismic energy interacts with different structures.
“Information from residents who experienced the shaking is valuable for analysis. It helps us better understand the characteristics of local seismic activity,” he said.
On why Segamat experienced the tremors, Mohd Zamri pointed to the ancient Muar fault line, which has long been considered inactive.
“The stress from surrounding tectonic plates may have been released along this old fault, causing the tremors we felt. It is a case of external forces acting on internal weaknesses,” he said.
